Surgery Exam Topics 2022/2023 PDF

Topics for surgery exam 2022/2023 1. Halsted’s Principles of Surgery William Stewart Halsted - American surgeon - 1852-1922 - emphasized strict aseptic technique during surgical procedures - introduced fundamental surgical principles that bear his name -...

Topics for surgery exam 2022/2023 1. Halsted’s Principles of Surgery William Stewart Halsted - American surgeon - 1852-1922 - emphasized strict aseptic technique during surgical procedures - introduced fundamental surgical principles that bear his name - developed conduction anesthesia by injecting his own nerve trunks with cocaine Halsted’s Principles of Surgery 1. strict asepsis during preparation and surgery 2. handle tissue gentle 3. preserve blood supply 4. good hemostasis to improve visibility and limit infection and dead space 5. minimize tissue trauma 6. minimize surgery time through knowledge of anatomy and technique 7. appose tissues accurately (place near each other) 8. keep tissues moist, especially abdominal and thoracic organs 9. correct use of instruments and materials 10. make pretty skin sutures Basic techniques - incision and excision of tissues (approach) - maintenance of hemostasis - handling and care of exposed tissues - use of sutures, knots, and other materials to restore anatomical structure and support tissues during healing 2. Incision and excision of tissue Incision and excision of tissue Using of scalpel - sharp scalpel with disposable steel blades is standard soft tissue cutting instrument - scalpel is used for sharp incisions where plane of tissue to be cut is known and identified, and likelihood of damaging adjacent structures is minimal - in general, tissues that are incised with scalpel are collagen-rich and poorly vascular - scalpel is used to make stab incision through tough layers (linea alba, submucosa of the stomach and bladder wall) - scalpel should NOT to be used for: o extensive subcutaneous exploration o anatomical style dissection to tease tissues apart for greater visualization - larger blades (e.g. No 10 and 20) are generally used to make long straight incisions KOE EI TARVI MUISTAA NUMEROITA  - smaller blades (e.g. No 15) are useful for thinner skin, curving incision and those that need to follow contours - small pointed blades (e.g. No 11) are used to make stab incisions or for sharp dissection in restricted areas such as joints Straight skin incision - for straight skin incision with large blade, scalpel is held in palm of hand with for finger stabilizing grip (palm grip), guiding it and modulating amount of pressure Contoured skin incision - for contoured skin incision, or one made with smaller blade, scalpel is best held in standard pencil grip, which facilitates using tip of blade Grips of scalpel - pencil grip – allows shorter, finer and more precise incision, scalpel is 30-40 degree greater angle to tissue - palm grip is strongest grip on scalpel and allows exertion of great pressure on tissues (often unnecessary) (used in cow) - fingertip grip offers best accuracy and stability for longer incisions Methods of cutting with scalpel - press cutting o use pencil grip and application if increasing pressure in same direction as proposed motion of blade o used to initiate incision is hollow, fluid-filled structures (gastrotomy, cystotomy) - sliding o safest and most common method of incising tissues with scalpel o uses pencil grip for short incisions through delicate tissues o fingertip grip is preferred for long incisions Skin incision - skin should always be immobilized be thumb and forefinger of nondominant hand, to ensure that it does not slide away or bunch up as scalpel passes, which would lead to ragged incision or one that slices obliquely through skin, increasing postoperative inflammation and discharge Stab incisions - layer of tissue to be incised should be immobilized with forceps or stay sutures, and pulled taut to avoid it moving away from blade - it should be elevated from underlying structures that could be damaged by blade Parameters of incision - length - shape o linear incision o spindle shaped incision - direction Using of scissors - scissors are best suited for flaccid tissues - properly used, scissors stabilize flaccid tissues between blades during cutting and provide excellent control over both depth and direction of incision - scissors are used for either sharp or blunt dissection - sharp dissection: scissor cutting, push cutting Grips of scissors Blunt dissection - blunt dissection means tearing instead of cutting - blunt dissection is technique for gently separating tissues while avoiding injury to important nearby structures such as blood vessels, nerves, or veins - unless using too much force, subcutaneous tissue and muscle will separate easily, while surrounding nerves, vessels, and tendons will remain intact - blunt dissection can be done by fingers, probe, forceps and scissors - fingers are first and best dissecting instrument 3. Hemostasis Hemostasis - hemostasis is a complex procedure that involves platelet activation and circulation clotting factors - good hemostasis is one of most important principle of surgery - hemostasis is important because: o bleeding blocks vision on surgical field, reducing operative accuracy and efficiency o blood on field, gloves, instruments and drapes provides ideal environment for bacterial growth and increases likelihood of infections o extravasated blood is irritating to tissues, prevents proper coaptation of wound edges, delays healing and encourages infection o severe or protracted hemorrhage may result in shock, progressive hypoxemia, and death of patient Methods of hemostasis - digital pressure - hemostats - packing with surgical swabs  - lavage with saline - ligatures - topical hemostatic agents - tourniquets Digital pressure - digital pressure stems flow while enough platelets accumulate to form a plug, or stable clot forms - pressure should be applied for at least 6o seconds in cases of minor hemorrhage and up to 5 minutes for more serious hemorrhage - hemostasis may be assisted by first applying surgical swabs to site, providing scaffold upon with blood clot can form - digital pressure is recommended as first strategy for bleeding even from large arteries and can be effective Hemostats - if simple digital pressure is ineffective, bleeding point can be identified and hemostat applied - hemostat crushes tissues releasing tissue thromboplastin that further stimulates coagulation - hemostats are left on position for at least 5 minutes Surgical swabs (good for oral cavity, eye cavity) - if bleeding point is deep within tissues, body cavity, or in close proximity to structure that might be damaged by hemostasis, further pressure may be applied by packing cavity tightly with surgical swabs - swabs are packed on top of one another and held in position until blood stops oozing through fabric - packing can be used for single bleeding points, or generalized bleeding from viscera such as liver - packing is left in place for at least 5 – 10 minutes, after what packing is removed piece by piece, last swab is removed carefully to avoid dislodging blood clots Lavage with saline - if hemorrhage continues in body cavity or confined space, it can be difficult to identify exact point of bleeding - saline lavage to remove blood clots and clear the field, then flooding area and looking down through saline pool, can be helpful for lifting adjacent flimsy tissues away from bleeding point - ongoing hemorrhage into saline pool appears as “chimney smoke” from bleeding point - pressure and cold temperature of saline, will also help in stopping bleeding Ligatures - ligatures are used for discrete bleeding points that are unlikely to stop of their own accord, or where it is feared they may resume bleeding during surgery - simple ligature - source of bleeding should be grasped by hemostat with minimal inclusion of neighboring tissues - surgeon passes thread around vessel, and ties off vessel with knot  - after first knot has been tied, surgeon removes artery forceps and ties second knot, and cuts threads with scissors just above knot (leaving as little thread, as possible – foreign material!) Simple ligature Transfixing ligature (used in ovariohysterectomy bc will not slip) - transfixing ligatures pass through structure to be ligated before being wrapped around and tied again - this serves to reduce risk of ligature slipping off end of pedicle and facilitates maintenance of inward pressure - transfixion ligatures are appropriate for closed castration, particularly in large dogs, where slippage of vessels within tunica vaginalis might otherwise occur - they may be also applied to suspensory ligament of ovary for ovariohysterectomy, to flat surfaces, such as liver or perforated blood vessel where complete occlusion of lumen is not desirable Mass-ligature Diathermy - diathermy (electrosurgery) units produce heat at surgical site for coagulation - makes use of high-frequency electrical current to o cut o coagulate o fulgurate Monopolar diathermy - pencil instrument - active electrode is placed in entry site and can be used to cut tissue and coagulate bleeding - return electrode pad is attached to patient, so electrical current flows from generator to electrode through target tissue, to patient return pad and back to generator - risk of patient burns presents Bipolar diathermy - forceps electrode - used for those procedures where tissues can be easily grabbed on both sides - current moves through tissue that is held between forceps - gives better control over area being targeted, and helps prevent damage to other sensitive tissues - risk of patient burns is very low Diathermy Bleeding from skin edges 1. apply pressure o most bleeding from skin edges stops on its own after pressure is applied over area for few minutes with swab 2. if you have access to electrosurgery device o wipe away blood and touch bleeding spot with electrode, bleeding usually stops 3. close wound with continuous suture Bleeding from blood vessel 1. apply pressure o it prevents further blood loss and may allow vessel to clot, thereby stopping bleeding o try this technique for at least 2–3 minutes o if it is unsuccessful, following alternatives should be tried 2. if you have access to an electrosurgery unit o if the vessel is vein or small (1–2 mm) artery 3. if you do not have access to electrosurgery unit or if vessel is larger vein or larger (3–4 mm) artery, end of vessel should be ligated off with suture for secure hemostasis 4. Care and handling of tissue Care and handling of tissue - avoid excessive blunt dissection - avoid excessive traction - handle tissues only when absolutely necessary - separate only those tissue planes necessary for visualization excision - keep tissues moist with regular application of saline - avoid exposure to irritant or inflammatory substances (e.g. talc, lint, urine, bile, blood, intestinal contents) - avoid repeated changes in retractor position - do not allow retractors to tear or stretch tissue excessive - use appropriate instruments Using surgical thumb forceps - toothed forceps (surgical) are designed to grasp tissue and prevent it sliding between jaws, while use of toothed forceps might be seem to be overly traumatic, it is preferable to using blunt forceps and having to reapply them as they lose their grip  - atraumatic forceps are indicated for fragile tissues such as liver, lung or blood vessels, where perforation will result in leakage of air, blood or other fluid, these forceps are used for grasping and tissue manipulation but are not appropriate for tissue retraction 5. Closure of tissue planes Closure of tissue planes Goals of closure of tissue planes - immediate restoration of function (muscle bellies, pleural space) - eliminate risk of displacement of contents (abdominal wall, hollow organs) - elimination of dead space - haemostasias (particularly in subcutis) - relief of tension of other layers - restoration of epithelial coverage Closure of tissue planes - number of layers and types of suture pattern should be chosen to fulfil above goals in timely fashion without excessive tissue handling and without leaving inappropriately large amounts of suture material in wound - it is not always necessary to close every tissue plane that was incised, and some individual tissue planes may be combined for closure - closure of tissue planes should ideally not impede normal movement of tissue (gliding of tendons, independent action of muscles) 6. Minimizing operative time Minimizing operative time - increased surgical time leads to higher infection rate - tissues dry out - there is more opportunity for tissue handling (which in itself causes trauma) - there is more bacterial contamination from the environment - the patient is subjected to longer anesthetic time with grater risk of hypotension, hypothermia, hypoxia and dehydration Common mistakes that prolong surgical time - poor positioning on operation table - poor understanding of local anatomy - fear to cutting wrong thing - poor retraction and visualization - keeping untidy instrument table - not establishing adequate hemostasis Simple principles for surgeon - develop surgical plan preoperatively  - make sure that person positioning patient on table knows exactly what is required for given procedure - review important anatomy!!! - practice skills in identifying and dividing tissue planes - use surgical assistant - If nervous or flustered, take time out! Take a few deep breaths. Enjoy yourself! DON’T PANIC! Additional tips - anamnesis - physical examination - laboratory investigations - do not be afraid - do not be afraid to say no - be prepared Post surgical complication are normal, but you can minimize them! 7. Topographic anatomy of soft abdominal wall The body wall - body wall consists of sheets of muscle that maintain abdominal integrity, provide support and strength for movements - open surgeries on intra abdominal structures involves breaching this well designed system, and it is important to ensure robust and long lasting repair Topographic anatomy of soft abdominal wall - muscles o external abdominal oblique (cranioventral) o internal abdominal oblique (caudoventral) o transversus abdominalis (dorsovental) o rectus abdominis (craniocaudal) - ventral abdominal wall (from exterior towards interior) o skin o external lamina of rectus sheath  o abdominal rectus muscle o internal lamina of rectus sheath o transverse fascia o peritoneum - lateral abdominal wall (from exterior towards interior): o skin o cutaneous trunci muscle o deep fascia o external abdominal oblique muscle o internal abdominal oblique muscle o transverse abdominal muscle o transverse fascia o peritoneum External abdominal oblique muscle Internal abdominal oblique muscle Transverse abdominal muscle Abdominal rectus muscle Transverse fascia and peritoneum Abdominal cavity - exam question: should we stitch peritoneum when closing the abdominal wall? → answer: no, because extremely painful to stitch Female Male (remember external pudendal artery) Topographic anatomy of soft abdominal wall - Linea alba (linea alba) – is fusion of aponeuroses (sheet elastic tendolike) of external and internal oblique abdominal muscles at median level of ventral abdominal wall, between two rectus abdominis muscles - Linea alba is wider in cranial part of abdomen and narrower – in caudal part Natural openings - femoral canals – separated from inguinal canal with inguinal ligament - inguinal canals – bilaterally symmetrical openings in caudoventral abdomen - umbilicus – scar in middle of linea alba - also in diaphragm: artery, vein, esophacig openings 8. Exploratory laparotomy Laparotomy - surgical approach to abdomen - upper midline incision – extends from the xiphoid process to umbilicus - lower midline incision – extends from umbilicus to pubic symphysis area - paramedian incision - paracostal incision – parallel with last rib (for liver) Approaches Ventral laparotomy in small animals - indications: exploratory laparotomy, surgeries on abdominal organs - anesthesia: general anesthesia + regional and local - surgical site preparation: hair is clipped from xiphoid region to pubic bone, thereafter, surgical site is prepared in compliance with general aseptic rules - equipment: general set of surgical instruments, retractors (ex. Balfour retractor) Ventral laparotomy in small animals – step by step - incision is made either in front of or behind the umbilicus, if necessary – over umbilicus - after cutting through skin, subcutaneous tissue, and external lamina of rectus sheath, linea alba, becomes exposed - make stab incision to line alba with scalpel - stab incision and letting air into abdominal cavity allows abdominal organs to “fall” dorsally, away from ventral aspect of abdominal wall - insert thumb forceps with tips placed caudally to lift upward on linea alba and make cranial to caudal incision - use systematic approach for abdominal exploration - abdominal organs should be inspected by direct vision and palpation first picture jejunum, mesentery, mesenterial lymphnode (lymphoma) linear foreign body in jejunum (licated jejunum) Closure - wound is closed using resorbable synthetic suture material - suture apposition of peritoneum is no longer performed since peritoneum heals rapidly without closure - first layer of simple continuous sutures is placed on external lamina of rectus abdominis (resorbable mono- or multifilament) - second layer is continuous sutures closes subcutaneous connective tissue (resorbable mono- or multifilament) - skin is closed with intra–dermic continuous suture (resorbable monofilament) or simple interrupted suture (non-resorbable monofilament) - muscles always tight Doing first cut you can remove it, to remove bleeding continuous is okay in abdominal wall stitch subcutis so good that you don’t need to stitch skin (but still stitch it) you can use any glue (that is transparent and instant) Complications - wound dehiscence or herniation - hemorrhage - suture abscess and reactions 9. Parts of abdominal wall hernia Hernias - hernia – protrusion of an internal organ throw defect in wall of anatomical cavity in which it normally lies - true hernia – is protrusion of abdominal contents through existing or potential opening in body wall that has become pathologically enlarged or disrupted - false hernia – is protrusion of abdominal contents through rupture of body wall - presented as subcutaneous swelling Abdominal wall hernias - abdominal wall hernias are abnormal openings in muscle wall of abdominal cavity that allow protrusion of intra-abdominal fat or organs into subcutaneous or intramuscular space - most often congenital Hernias - umbilical hernia (hernia umbilicalis) - scrotal hernia (hernia scrotalis) - abdominal hernia (hernia abdominalis) - inguinal hernia (hernia inguinalis) - perineal hernia (hernia perinealis) - femoral hernia (hernia femoralis) - diaphragmatic hernia (hernia diafragmalis) - hiatal hernia (hernia hiatus) Parts of abdominal wall hernia - hernial ring is actual defect in abdominal wall - hernial sac (external and internal) surrounds hernia contents - hernial contents are organs or structures that are permitted to pass through ring (commonly fat, intestinal loop or omentum) - true congenital abdominal hernias have peritoneal sac surrounding hernia contents - false (traumatic) hernias do not have peritoneal sac Reducible vs irreducible - reducible abdominal wall hernias appear as small, soft, nonpainful swellings with hernia contents that can be gently manipulated (reduced) back into abdominal cavity - if hernia is firm and tissues within it are not freely movable, hernia is classified as irreducible (incarcerated) 10. Umbilical hernia Umbilical hernia (hernia umbilicalis) - occur on ventral abdominal midline through umbilical ring - hernia is formed because umbilical ring in abdominal wall during fetal development does not either grow over or gets ruptured during birth (traumatic) - breed predisposition: basenjis, Pekingese, pointers (gastroschisis in puppy, organs out of abdominal cavity) - we can recommend to fix the hernia when in ovariohysterectomy, no need to rush to surgery, in the same time as other abdominal surgery Surgery of reducible umbilical hernia - animal is fixed on its back or in dorsal position - surgical site is cleaned and disinfected in compliance with general aseptic rules - equipment: general set of surgical instruments  - in case of small umbilical hernia that contains only fat, incision is made directly over hernia o internal hernial sac is inverted and hernia ring is closed without debriding edges of ring o simple interrupted suture pattern with synthetic monofilament absorbable or nonabsorbable - in case of a large or inflamed hernia, incision is made around it - thereafter, through surgical wound, internal hernia sac is separated from external one using fingers (scissors and scalpel can also be used) - it is necessary to expose 1–2 cm of hernia ring around abdominal wall - internal hernial sac is reduced into abdominal cavity - edges of hernial orifice are joined with simple interrupted suture - after such surgery internal hernial sac remains intact and abdominal cavity closed - skin is closed with interrupted suture, non–resorbable synthetic suture material is used Surgery of irreducible hernia - surgical technique is similar to one of used for reducible hernia - if hernia contains irreducible fat and/or omentum, they are ligated at base of hernia and removed, and hernia ring closed routinely - if herniated contents contain intestines or other abdominal organs, hernia ring should be enlarged cranially and caudally along Linea alba Surgery of squeezed hernia - if intestines or other organs were squeezed inside of hernia, viability of these should be examined - if intestine contains gases or fluids, it is first punctured - in case of necrosis resection and anastomosis or organ removal should be performed Umbilical hernia - if abdominal muscles are weak or severely damaged, Marlex or Prolene synthetic mesh is used for closing - postoperative treatment and care: o in case of irreducible or squeezed hernia, antibacterial therapy is prescribed o analgesia o skin sutures are removed 10 – 14 days after surgery o collar - possible complications: o wound infection o reherniation - prognosis: o commonly good 11. Inguinal hernia (direct vs indirect) Inguinal hernia (hernia inguinalis)  - in case of inguinal hernia, omentum, rarely, loop of small intestine, bladder, part of large intestine or uterus protrude through from abdominal cavity into inguinal canal - this type of hernia occurs in all animal species, although it is more frequent in small dog breeds (Miniature Poodle, Pomeranian Spitz, Chihuahua, Pekingese, American Cocker Spaniel, Cavalier King Charles Spaniel) - this type of hernia rarely occurs in felines - obesity, chronic constipation, and gestation may contribute to hernia formation - it may be congenital and inherited, or traumatic - it can be uni- or bilateral - in dogs, unilateral hernia is most frequently formed on left - inguinal hernia may be direct and indirect o in case of direct hernia, hernial contents (omentum or organs) protrude through inguinal canal near vaginal process (more frequent in female animals) o in case of indirect hernia, hernial contents protrudes through vaginal process into vaginal cavity (in males) and may also form scrotal hernia Inguinal canal (canalis inguinalis) - paired inguinal or vaginal canal is located in rear part of ventral/ anterior abdominal wall - pubic artery, vein, and nerve, as well as, in male animals, spermatic cord (including blood vessels and nerves) and cremaster muscle, and, in female animals, round ligament of uterus, go through this region veins etc more caudally!! leave open for those if correcting hernia from here (caudoventrally) Inguinal canal (hernia inguinalis) - superficial inguinal ring is slit–like external entrance going posteriorly from the anterior part of inguinal canal, it is formed by external abdominal oblique aponeurosis and inguinal arch - deep inguinal ring is internal entrance into inguinal canal, it is formed by caudal edge of internal abdominal oblique muscle, inguinal arch, and transverse fascia Inguinal hernia - etiology: o anatomic factors o hormonal factors o metabolic factors Surgery of inguinal hernia - knowledge on topographic anatomy is essential! - having prepared surgical site, incision is made from above superficial inguinal ring till internal hernial sac - internal hernial sac is fixed using fingers and bluntly dissected along its whole length till hernial orifice - internal hernial sac is cut open and hernial contents is reduced back to abdominal cavity - empty internal hernial sac is ligated in its neck, amputated and hernial orifice is closed with interrupted suture using synthetic slowly resorbable or non–resorbable suture material - NB! o it is crucial to remember that external pudendal artery, vein, and genitofemoral nerve are located in caudomedial part of inguinal canal o be careful when closing not to damage them, severe hemorrhage may occur, if those are damaged, it is equally important not to press or ligate these blood vessels and nerve - empty the bladder if suspected to be in the hernia Surgery of inguinal hernia - subcutaneous tissue is closed using synthetic resorbable suture material, it is essential not to leave any hollows, as tissue proliferation level in this region is very high - skin is closed with intra–dermic suture (resorbable monofilament) or simple interrupted suture (non–resorbable monofilament) - postoperative treatment and care: o analgetics (NSAIDs, opioids) o commonly, antibacterial therapy is not necessary o collar! o activity restrictions for at least 14 days after surgery! - ovariohysterectomy is recommended Inguinal hernia - complications (statistically 17%) o hematoma o pain when moving  o severe edema in the inguinal region o wound infection o reherniation - prognosis: good 12. Scrotal hernia Scrotal hernia (hernia scrotalis) - in case of scrotal hernia, loops of small intestine protrude through inguinal canal into scrotum, where they are either located in vaginal cavity (more frequently) or outside parietal lamina of tunica vaginalis - it occurs in all species, although is most frequent in swine - it is commonly congenital - scrotal hernia is usually reducible, irreducible scrotal hernias are rare, and squeezed hernias – very rare Scrotal hernia in canine/ dogs - indirect inguinal hernias - occur rarely - young male animals - surgery is performed promptly after diagnosis - high risk of adhesions - surgery may be performed together with castration (recommended) or without it - incision is made above inguinal canal - hernial contents is reduced through inguinal canal into abdominal cavity (if necessary, internal hernial sac is opened) - internal hernial sac (parietal lamina of tunica vaginalis) is narrowed in hernial neck area close to hernial orifice (inguinal canal) using mattress suture - cranial part of inguinal canal is closed with slowly resorbable suture material - surgery of hernia combined with castration - internal hernial sac is opened, hernial contents is reduced through inguinal canal - testicle is massaged out through scrotum, ligament of epididymis is cut through, blood vessels and sperm duct are ligated and cut through - internal hernial sac is ligated in its neck area close to inguinal canal and removed - inguinal canal is closed with interrupted suture without pressing or ligating blood vessels and nerve - thereafter, other testicle is removed Femoral hernias - extremely rare - abdominal fat is seen protruding caudomedial to femoral artery and vein - may be consequence of trauma, prepubic ligament rupture or complication of pectineal myectomy 13. Topographic anatomy of gastrointestinal system Gastrointestinal surgery Stomach topography - stomach is continuation of esophagus located in cranial part of abdominal cavity - shape of stomach depends on its degree of its fulfilment o empty or moderately filled stomach looks like V-shaped curved bag o significantly filled stomach is more or less spherical - lower curved part of stomach is termed greater stomach curvature and area between upper part of esophagus and end of stomach – lesser stomach curvature - ventrodorsal view: o right: fundus of stomach (fundus ventriculi), corpus of stomach (corpus ventriculi) o left: pylorus (pylorus) Stomach structure - stomach wall consists of four layers: o mucous membrane o submucosa (strongest layer) o muscular layer o serous membrane Stomach topography - stomach has structurally four ligaments that hold it in place: o hepatogastric ligament (lig. hepatogastricum) o hepatoduodenal ligament (lig. hepatoduodenale) o gastrosplenic ligament (lig. gastrolienale) o gastrophrenic ligament (lig. gastrophrenicum) - (all of these ligaments can be cut) Stomach blood supply - celiac artery (a. celiaca) supplies stomach with blood, this artery starts from abdominal aorta in between lumbar and diaphragmic regions, it is relatively short blood vessel (1–2 cm) - in dogs, this artery is divided into three blood vessels: o splenic artery (a. lienalis) o left gastric artery (a. gastrica sinistra) o hepatic artery (a.hepatica) - most important: there is gastrosplenic artery, ligate it if spleen removed, in greater curvature very important (gastroepiploic and on up left and right gastric!!!) (EXAMMM) Omenta - omenta are ligaments of abdominal organs, they, to greater or less extent, contain - adipose tissue - omentum is mesenterial membrane that has very intense blood and lymph supply, as well as angiogenic, immunogenic, and adhesive features Functions of omenta - hold stomach and other abdominal organs in place  - thanks to numerous blood vessels, function as blood depositaries - function as thermal insulators of abdominal organs - close wounds passing through abdominal wall - produce and resorb abdominal fluids - indirectly regulate blood pressure 14. Main principles of gastric and intestinal surgery Main principles of gastric surgery - compared to other parts of gastrointestinal tract (GIT), number of bacteria in stomach is significantly smaller - perioperative use of antibiotics is indicated - application of preventive antibacterial therapy depends on particular case - access o commonly, ventral median laparotomy is used, where incision starts from sternal manubrium and continues till umbilicus o Balfour retractors are usually used for better visualization of stomach o paracostal laparotomy is alternative access method (it is rarely applied) - minimizing contamination risks o stomach is isolated from laparotomy wound with large moist sterile tampons and sheets o fixating sutures are located in corners of presumable incision site (2–0, 3–0 monofilament with atraumatic needle) o different sets of instruments should be used for clean and clean–contaminated parts of surgery o local lavage using NaCl - closing gastric wound o 1st layer: mucous membrane is closed with simple continuous suture o 2nd layer: submucosa, muscular layer, and serous membrane are closed with intestinal suture (Cushing, Connell, or Lembert suture patterns) o omentalisation! (draining abdominal abscess by putting omentum inside) - choice of suture material o absorbable monofilament: polydioxanone, polygliconate, polyglicapron 25 o thickness: 4–0 – to be used on cats, 3–0 – small dogs, 2–0 – large dogs Main principles of intestinal surgery - fluid therapy o commonly, fluid–electrolyte balance disorders occur in gastrointestinal patients o in patients suffering from ileus, fluid secretion into lumen of intestine is increased and fluid absorption into blood flow is decreased o those patients are always dehydrated o animals with mechanic intestinal obstruction are usually hypopotassemic, hyponatremic, and hyperchloremic. o first thing to do is to rehydrate patient! If necessary, potassium is also administered - preventive use of antibiotics o small intestine of cats and dogs contains both gram–positive and gram–negative microflora o intestinal mucosal barrier does not allow bacteria to intrude into organism and isolates them within intestine  o if mucous membrane is mechanically or pathologically damaged, the bacteria may intrude into surrounding tissues and cause surgical infection o preventive use of antibiotics is indicated 60 min before surgery o usually, first generation of cephalosporin (cefazolin) is used - assessment of intestinal wall viability o viable intestinal wall ▪ is pink or red ▪ is with peristaltic activity ▪ is with pulsation of mesenterial blood vessels o clinical assessment may not always accurate o biopsy o fluorescein test - choice of suture material o it depends of particular situation o synthetic resorbable monofilament (polyglicapron, polydioxanone, polyglyconate) is perfect choice. o synthetic nonabsorbable monofilament (nylon, polypropylene) o it is also possible to use multifilament but it may induce contamination o all suture materials induce inflammatory reaction of intestinal wall, however, one induced by multifilament is usually more severe - choice of suture material for wound closing o submucosa is strongest layer of intestinal wall o correct closing of submucosa guarantees fast and efficient healing o in case of insufficient contact of submucosa edges, wound heals more slowly and less efficiently - choice of suture material for closing intestinal wound o contact of submucosa edges is better if a one–layer suture is used o two–layer suture may result in avascular necrosis in upturned tissue parts and prolonged healing period o only Schmieden, Cushing, or simple continuous suture types are used 15. Gastrotomy Gastrotomy - indications: o removal of foreign bodies from stomach o gastric ulcers o removal of gastric neoplasia (take all the 4 layers) - patient preparation: o 24–hour fasting o dehydration (fix this before) o preoperative antibacterial therapy – 2 hours before surgery - animal is placed and fixed on its back - abdominal wall is opened along median line between xiphoid and umbilicus - omentum is carefully pushed to side and stomach is taken out of wound to greatest possible extent  - fixating sutures are placed at both ends of incision in order to prevent retraction, needle only penetrates serous membrane layer - wound and area around it are covered with sterile sponges to avoid contamination - incision is made between greater and lesser stomach curvatures in less vascularized place - gastric contents is removed and gastric wall is examined - gastric wall is closed with two–layer suture - fixating sutures are removed - stomach is carefully reduced back to abdominal cavity - usually the site is between lesser and greater curvature, see the vessels, do not cut those, the incision can be both ways - postoperative treatment: o start to feed 4–12 h after surgery o fluid therapy o gastroprotectors (omeprazole, ranitidine) o antiemetic therapy o antibacterial therapy 16. Pyloromyotomy and pyloroplasty Pyloromyotomy and pyloroplasty - aim of pyloromyotomy and pyloroplasty surgeries is to increase diameter of pylorus - procedure is used as surgical solution for chronic pyloric mucosal hypertrophy or pyloric stenosis - both procedures should be performed with precautions, very carefully, because surgical failures and errors are particularly complicated to rectify Fredet-Ramstedt pyloromyotomy - it is least complicated method - effect of procedure is frequently temporary (effect short so teacher does not use this) - pylorus is held between index finger and thumb of non-dominating hand - longitudinal incision penetrating serous membrane and muscular layer is made into less vascularized area of ventral pylorus, mucous membrane should remain intact (in case of injury, it is closed with sutures) - it is important to make certain that incision has fully cut through muscular layer and exposed mucous membrane Heineke-Mikulicz pyloroplasty - simple method (most often used) - longitudinal incision is made into pyloric ventral surface - incision goes through all layers - fixating sutures are placed in middle of incision on both sides of wound - wound is closed transversally with simple continuous suture - suture material: 2–0 or 3-0 resorbable monofilament Y-U pyloroplasty - this method widens most lumen of pylorus - procedure starts with longitudinal incision (leg) in ventral part of pylorus - first, incision only penetrates through serous membrane - incision goes further and splits in two incisions going parallel to greater and lesser curvatures (shoulders) - thus, Y–shape incision emerges  - corner between „shoulders“ cannot be too sharp and narrow, as it can result in necrosis - all parts of Y-shape incision (leg and shoulders) should be of same length - when first incision through serous membrane is made, following incisions go deeper and penetrate through muscular level and mucous membrane - severely hypertrophied mucous membrane can be removed - closing of top of gastric wall starts at duodenal end of incision, incision is closed with - simple interrupted suture - thus, Y – shape incision turns into U – shape one - suturing continues in both directions - (do not leave triangles to wound since those will necrotize usually, make round edges) 17. Enterotomy, intestinal resection and anastomosis Intestinal surgery - enterotomy – opening of intestine - enterectomy or intestinal resection – removal of part of intestine - enteroplication (entero-enteropexy) – fixating parts of intestine to one another - enteropexy – fixating intestine to abdominal wall - enterotomy or intestinal resection o indications: ▪ removal of foreign bodies from intestine ▪ removal of neoplasias from intestine ▪ invagination treatment Intestinal anatomy - small intestine: o duodenum (duodenum) o jejunum (jejunum) o ileum (ileum) - large intestine: o caecum (caecum) o colon (colon) o rectum (rectum) Intestinal obstruction - this is frequently occurring pathology in dogs, cats, rabbits, or rodents - foreign bodies, invaginations, neoplasias, strictures - all types of obstructions may cause both local changes of intestine as well as systemic reactions - intestinal fluid contains lot of potassium, natrium, and hydrochloric acid o vomiting out intestinal fluid causes hyperchloremic hypopotassemia metabolic alkalosis Obstructions - changes in organism are, to major extent, related to fluid balance: excessive fluid secretions into lumen of intestine; malabsorption of water and water-soluble substances; fluid, electrolyte, and acid–alkali balance disorders; proliferation and translocation of intestinal microflora - - first adhesions, then button on stomach and in next wine cork in stomach - if you measure 5. lumbar vertebra, small intestine lumen should not be 2x much that, if it is, the surgery - intestinal torsion in pictures in base of mesentery → ischemia and necrosis, if everything like in the picture → euthanasia o you can remove 50-60% if needed but usually all the intestines are necrotized (mesenteric torsion) → euthanasia o tosion is by the base (around), volvulus is by the side (around own axis) Obstructions common place of obstructions, foreign bodies rarely but sand impaction is common Enterotomy - part of intestine containing foreign body is taken out through wound and isolated from wound with sterile tampons  - part of intestine under surgery, is emptied to both sides using fingers, and intestinal clamps are placed for 5–7 cm on both sides of operation site to prevent intestinal contents from flowing back - intestine is opened longitudinally on left side of mesentery above foreign body (scalpel number 11), length of incision should allow for easy removal of foreign body, if necessary, incision is lengthened using Metzenbaum scissors - after removal of foreign body, edges of enterotomy wound are cleaned and closed with one–layer simple continuous suture Intestinal resection and anastomosis - in order to be certain that anastomosis is performed on healthy and viable parts of the intestine, 3– 4 mm of healthy intestinal wall should be removed together with pathologically changed segment - during procedure, it is essential to keep mesenterial edge of intestinal segment longer than antimesenterial edge - moving intestinal segment is raised out of wound and, in order to prevent contamination, isolated from rest of abdominal cavity using sterile tampons or sheets - mesenterial blood vessels supplying this segment are ligated - mesentery is cut through in places, where blood vessels are ligated; attempt to preserve as much of mesentery as possible should be made - Doyen’s intestinal clamps are used to isolate segment of intestine Intestinal anastomosis - end–to–end sewing is preferred method - ends located between intestinal clamps are placed next to one another with their open ends towards surgeon, and intestinal edges located next to each other are joined starting from mesenterial edge (simple interrupted suture), furthermore, corners of intestine are sewn together at antimesenterial edge - afterwards, intestinal edges are closed on both sides using simple interrupted suture or simple continuous suture - mesentery is closed using simple continuous suture - we always need to see if there is blood supply, see the vessels feeding the area - you can go from mesentery to up, and other side also from mesentery up, do not go around, blood supply  - do not ligate the other vessels, stitch like 2 pic, use parallel mattress, if there is opening the intestine can go there → always leave it as close to previous anatomy - pictures for different diameter (not to use side-to-side) - ends of intestine are joined side–to–side if diameters of ends are significantly different, this method is rarely used nowadays - both ends of intestine are closed with two–layer suture (simple continuous suture, Cushing suture) - closed intestinal ends are placed next to one another along intestinal peristalsis, emptied from intestinal contents with stroking movements, fixated using intestinal clamps and joined close to mesentery with 4–8 cm of continuous sutures penetrating serous membrane and muscular layer Intestinal resection and anastomosis - stapling of intestinal ends o intestinal ends may be joined using gastrointestinal anastomosis stapler and thoracoabdominal stapler o quick and simple method o requires expensive equipment - two intestinal ends are placed side by side next to one another (antimesenterial edges contact) - legs of GIA–stapler are placed in each intestinal segment and antimesenterial edges are pressed together - GIA–stapler cutter is activated creating connection points between two segments - fixating sutures are placed on both ends of segment - TA–stapler is placed on ends hermetically closing them - free edges of ends are cut off Linear foreign body - start with opening mouth and see under tongue, next is gastrotomy and then going lower o do not pull → may make openings in there, if resistance, make incision Linear foreign body - linear foreign body location is determined. - process of linear foreign body removal via enterotomy starts in the proximal part of gastrointestinal tract - in order to remove linear foreign body from intestine, several enterotomy incisions are made - attempt to remove linear foreign body through only one incision may severely damage or perforate intestinal wall Enteroplication - fixating intestinal parts to one another - it is used to treat and prevent intestinal invagination - after correction of invagination or enterectomy, intestinal parts are placed side by side in loops trying to avoid occurrence any sharp bends - it is essential to appropriately fixate jejunum and ileum - it is not necessary to fixate duodenum as invagination rarely occurs in this part of intestine - when intestinal parts are evenly placed in loops side by side, they are sewn together with simple interrupted sutures using resorbable monofilament - sutures are placed between mesenterial and antimesenterial edges. - sutures penetrate serous membrane, muscular layer, and submucosa Complications following intestinal surgery - septic peritonitis - adhesions - short bowel syndrome (rare malabsorption disorder caused by a lack of functional small intestine, primary symptom is diarrhea) - ileus Postoperative treatment - fluid therapy - antibacterial therapy - analgesia o fentanyl o buprenorphine - antiemetic drugs - FEEDING! o enterocytes receive nutrients only directly from the feed present in intestine  o glutamine is primary nutrient for enterocytes o it is important to start feeding and watering 4 – 12 hours after surgery o it is essential to avoid hypoglycemia 18. Topographic anatomy of urinary system Terminology - cystotomy –surgical opening of the urinary bladder - urethrotomy– surgical opening of the urethra - cystectomy – surgical removal of a part of the urinary bladder - cystolithectomy– surgical removal of urinary bladder stones - urethrostomy– creation of a permanent urethral fistula Topographic anatomy of urinary bladder - position of urinary bladder depends on its degree of fulfilment and species - in carnivores urinary bladder, irrespective of degree of fulfilment, is always located on ventral abdominal wall, extending, in case of excessively full bladder, till umbilical region - urinary bladder can be considered as distensible balloon of smooth muscle, covered by serosa and lined by epithelium Urinary bladder - dorsal and ventral surfaces are distinguished in full pear–shaped urinary bladder - urinary bladder consists of: o neck o body o apex Topographic anatomy of urinary bladder - urinary bladder ligaments: o median vesical ligament (lig. vesicae medianum) is thin ligament that extends to umbilicus and holds urinary bladder attached to pelvic floor (A) - bladder is laterally attached to sides of pelvis with pair of lateral vesical ligaments (lig. vesicae laterale) (B) - ureters enter neck of bladder and, in males, sperm ducts, located in urogenital sulcus on top of bladder, enter opening of urethra - urethra starts at neck of bladder - blood supply: cranial, middle and caudal vesical arteries - vesical wall comprises (from outside inwards) serous membrane, muscular layer, and mucous membrane - smooth mucosal area located between two ureter orifices and internal urethra orifice is termed vesical trigone Innervation Blood supply Urethra - urethra (urethra) is organ through which urine leaves bladder - urethral wall comprises (from outside inwards) external membrane, muscular layer, and mucous membrane 19. Main principles of urinary surgery Main principles of urinary bladder surgery  - incision wounds in healthy bladder heal very quickly - it only takes mucous membrane five days to heal - it only takes entire vesical wall 14–21 days to regain its normal strength - various resorbable synthetic monofilaments are suitable for sutures of vesical wall - non resorbable suture material or surgical clamps are not suitable for closing vesical wall as they may cause appearance of vesical concernments (in 9.4% of dogs and 4% of cats) - thickness of suture material is 3–0 to 5–0 - round atraumatic needle is used - suture materials → - sutures o suture must not penetrate mucous membrane! o one–layer sutures used for closing vesical wall ▪ simple continuous suture - antibacterial therapy o it is not commonly needed o E. coli, Proteus spp., Staphylococcus intermedius o if surgery lasts longer than 90 min, following drugs are used: ▪ amoxicillin with clavulanic acid ▪ third generation cephalosporins ▪ enrofloxacin 20. Cystotomy Cystotomy - indications: removal of urinary stones from the bladder, biopsy of vesical tumors and tumor removal, treatment of vesical ruptures - urinary stones occur in all animals, however, they are most frequent in dogs and cats, mainly in male animals - commonly, part of vesical wall is removed together with tumor, even if 75% of wall is removed, it completely regenerates in 3–4 months! - approach: caudal median laparotomy; in male dogs, incision is continued laterally from prepuce - at beginning, surgeon checks whether there is any free urine in abdominal cavity - urinary bladder is carefully palpated, if it is full – it is punctured using syringe - before opening, bladder is taken out of wound and isolated using large tampons and sheets to avoid abdominal contamination - on both sides of presumable incision at apex of the bladder fixating sutures are placed - incision into ventral or dorsal wall is made using scalpel nr 11 - incision is close to apex and away from ureters and urethra, in between blood vessels, incision is lengthened using scissors - all layers are penetrated - ventral cystotomy allows for more efficient examination of vesical trigone region  - mucous membrane needs to be handled very carefully! - do not damage vesical trigone! - bladder stones need to be carefully removed using surgical spoon - catheter is retrogradely inserted into urethra and latter is rinsed - afterwards, urinary bladder is rinsed using NaCl 0.9% solution (at least three times) - biopsy of mucous membrane sample is conducted as part of bacterial examination - after closing, bladder is reduced back into abdominal cavity - laparotomy wound is closed with three–layer suture - post–operative treatment and care: o analgesia (opioids, NSAIDs) o fluid therapy o antibacterial therapy if indicated o catheter remains in the bladder for 2–3 days, bladder is rinsed 21. Urethrotomy and urethrostomy Recovery of urethra - in optimal conditions, it takes mucous membrane seven days to completely recover. - risk of edema of urethral tissues - catheterization? + stricture prevention - catheter may cause mucous membrane irritation - suture material: fast–absorbable monofilaments (rapid) 4– 0, 5–0: polydioxanone (Ethicon), polyglyconate (Maxon), poliglecaprone (Monocryl) Urethrotomy in small animals - indication: treatment of urethral obstructions - urethrotomy: o prescrotal o scrotal o perineal Prescrotal urethrotomy in male dogs - procedure is used to remove stones from distal urethra - anesthesia: general anesthesia - insert sterile catheter into urethra till place of obstruction  - animal is placed on its back - cutaneous incision of 1–2 cm is made above obstruction between penile bone and scrotum, incision continues till retractor muscle of penis - retractor muscle is visualized, mobilized and pushed laterally to get access to urethra - penis is fixated using fingers - urethra is normally 3–4 mm wide, pink, surrounded by white cavernous bodies - afterwards, urethra is opened using scalpel and the stones are carefully removed - urethra is rinsed using NaCl 0.9% solution - catheter is inserted further into bladder. - urethra is left to gradually recover (in this case, catheterization is necessary) or closed with simple continuous suture using synthetic fast–resorbable monofilament (4–0 or 5-0) - wound is closed with a two–layer suture: o 1. subcutaneous tissue is closed with simple continuous suture o 2. skin is closed with subcuticular suture - post–operative complications: hemorrhage, urethral stricture Perineal urethrotomy in male dogs - perineal urethrotomy is used for stone removal from isthmus of urethra, place where urethra bends around ischial arch (isthmus urethrae) - animal is in prone position, tail is raised and fixated in this position - anus is closed with tobacco–pouch suture - sterile catheter is inserted into urethra till the obstruction place - skin and subcutaneous tissue are cut through with scalpel in middle between anus and scrotum - retractor muscle is visualized, mobilized and pushed laterally - paired bulbospongiosus muscles are separated from one another in their adhesion point - afterwards, corpus spongiosum is incised and urethra opened - urinary stones are removed and urethra – rinsed - catheter is inserted into bladder - urethra is left to gradually recover or is closed using resorbable monofilament (4–0, 5–0) - corpus spongiosum is closed with simple continuous suture using synthetic resorbable suture material (4–0) - wound is closed with two–layer suture: o 1. bulbospongiosus muscles and subcutaneous tissue are closed with simple continuous suture o 2. skin is closed with subcuticular suture Urethrostomy  - indications: o urinary stone removal o urethral stricture o urethral neoplasia or trauma o penis amputation - depending on exact place of procedure, prescrotal, scrotal, perineal and prepubic urethrostomies are distinguished Prescrotal urethrostomy - prescrotal urethrostomy is performed similarly to prescrotal urethrotomy o only difference is that, in case of urethrostomy, mucous membrane is attached to skin. - length of incision has to be 6–8 times longer than diameter of urethra - urethral mucous membrane is attached to skin with simple interrupted suture using synthetic resorbable monofilament 3–0 to 5–0) - suturing starts in caudal corner of incision Scrotal urethrostomy in male dogs - procedure is performed together with castration - this is preferred method because urethra is wider and more superficial in this region, and cavernous tissue around it is thinner - animal is castrated via scrotum - afterwards, incision penetrating subcutaneous tissue is made above urethra - retractor muscle is visualized, mobilized and pushed laterally - urethra is opened longitudinally above catheter - urethral mucous membrane is attached to scrotal skin Perineal urethrostomy in male dogs - this method is only used if other methods are not possible - cavernous tissue in this region is thick and hemorrhage may be profuse - technique is similar to perineal urethrotomy one - length of skin incision is 4–6 cm, and length of urethral incision is 1.5–2.0 cm  - urethral mucous membrane is attached to skin with interrupted suture Perineal urethrostomy in male cats - major site for urethrostomy in cats. - in majority of cases, this site adequately addresses obstructive lesions in distal urethra Surgical manipulations - penis is dissected free of underlying and surrounding tissues - reflect penis dorsally and to either side to unable ischiocavernosus muscles to be isolated and sectioned - enable penile ligaments. Trim retractor penis muscle away from its dorsum. - make longitudinal incision into dorsal penile urethra and amputate distal penis 22. Topographic anatomy of male/female genital organs Genital organ surgery - remember difference of sterilization or castration (sterilization is leaving the organs behind but ligating the organ for not be able to reproduce, castration is taking something out) Male – castration (castratio, orchidectomia) - it is probably one of oldest surgical techniques in world - indication: o sexual urge suppression (all species) o prevention of escape from home (cats and dogs) ▪ (for bunnies does not always work for all behavioral issues, remember to tell to owner) o therapeutic purposes (inflammations of testes, scrotum, spermatic cord, and prepuce or neoplasms, prostatic hypertrophy) o prevention of congenital diseases (most commonly in pets) - adrenal glands also produce testosterone! → animal will not be without sex hormones Testis - paired ovoid organs, located in scrotum - responsible for producing male hormones and gametes Topographic anatomy - scrotum (scrotum) – is protrusion of abdominal wall - scrotum has two integuments: o skin of scrotum (cutis scroti) – is relatively thin layer that may be pigmented ▪ very sensitive in dogs  o dartos tunic (tunica dartos) – consists of omnidirectional smooth muscle cells that extend into skin, elastic and collagen fibers, which wrinkle skin of scrotum in case of thermal and mechanical irritation - integuments of testis and spermatic cord: o external spermatic fascia (fascia spermatica externa) o cremaster muscle (musculus cremaster) starts at iliac fascia and adheres to vaginal tunic of testis o (internal spermatic fascia????) o vaginal tunic (tunica vaginalis) – actually peritoneum, thickest one ▪ visceral laminae (lamina visceralis) covering spermatic cord, testis and epididymis ▪ parietal laminae (lamina parietalis) located externally - area between visceral and parietal laminae at spermatic cord level is termed canalis vaginalis (canalis vaginalis); and one at level of testis – cavum vaginale (cavum vaginale) - blood supply: o testis: testicular artery and vein (a. et v. testicularis) o scrotum: external pubic and cremasteric artery (a. cremasterica), venous blood flows along veins bearing same names - innervation: o testis: sympathetic fibers of caudal mesenteric plexus (plexus mesentericus caudalis) o scrotum: iliohypogastric nerve (n. iliohypogastricus), ilioinguinal nerve (n. ilioinguinalis), genitofemoral nerve (n. geniofemoralis) - cremaster muscle in the picture - gubernaculum ligament – pull testes out into the scrotum, since in newborn animals not always in scrotum (EXAM) Blood supply (artery starts from aorta) Female – topographic anatomy of female genital organs in carnivores  - ovaries are located in abdominal cavity caudally from kidneys, close to apex of uterine horn - they hang on mesovarium - bursa ovarica (bursa ovarica) surrounds ovary and is located in middle latter, mesovarium, and mesosalpinx - utero–ovarian ligament (lig. ovarii proprium) is fibromuscular formation located between uterine side of ovary and apex of uterine horn - lymph and blood vessels, as well as nerves enter ovary via mesovarium - cranial thickened edge of mesovarium forms suspensory ligament of ovary (lig. suspensorium ovarii) - in dogs, deep and rich in adipose tissue bursa ovarica completely surrounds organ - in cats, bursa ovarica does not contain adipose tissue and only laterally covers ovary - shortness of suspensory ligament of ovary in dogs, makes surgical removal of ovary more complicated, unlike cats, ligament in dogs is not vascularized - blood supply: ovarian artery, frequently – branches of uterine artery - uterus is tubular organ comprising uterine horns, body and cervix - uterine cavity is inside uterine horns and body - uterine wall consists of three layers: serous membrane, muscular layer, and mucous membrane - uterus attaches with following ligaments: o mesometrium (mesometrium) attaches uterus to pelvic dorsal wall and lumbar region, mesometrium, mesosalpinx, and mesovarium form broad ligament of uterus (lig. latum uteri) o round ligament of uterus (lig. teres uteri) attaches to deep inguinal ring or vaginal process - in carnivores, uterine cervix and body are relatively short - thin uterine horns start behind ovaries and are located in abdominal wall, they split at body and form Y – shaped structure - uterine horns are partially connected with intercornual ligament (lig. intercornuale) - blood supply: uterine artery starts from pubic artery and anastomoses uterine branches of ovarian and vaginal arteries 23. Male/female neutering surgery MALE: Closed method  - during procedure performed using closed method, scrotum is opened with incision going till parietal lamina of vaginal tunic - latter is preparated off surrounding tissues, and testis with parietal lamina of vaginal tunic are removed, testis and spermatic cord remain covered with parietal lamina of vaginal tunic, cavum vaginale remains closed - this method is used in case of various pathologies, e.g. invaginated and scrotal hernias, risk of intestinal prolapse, as well as necrosis or inflammation of testis (or abscess, tumor etc) o usual castration may be also performed using closed method but we prefer the open method - insicion prescrotally in dogs since so sensitive skin Open method - in case of open method use, both scrotal wall and parietal lamina of vaginal tunic are cut through, opening cavum vaginale, and, thereafter, exposed testis is removed - this method is only used when there are no pathological changes are in the testes, vaginal tunic, or inguinal canal - opening vaginal tunic, testicle popped out, (when out- spermatic duct) - attachement of gubernaculum, break the ligament - 2 ligatures! Anesthesia - general anesthesia combined with local anesthesia o infiltration of incision line and parenchyma of testis: needle is inserted above incision line into testis, bottom–up, ¾ of its depth and 2% lidocaine solution is injected into parenchyma of testis o thereafter, tip of needle is pulled below skin, and incision line on scrotum is anesthetized Castration of dogs and cats - testes are small and longitudinal axis is located diagonally - in dogs, scrotum is located between thighs and is visible from behind - in cats, scrotum is located directly between anus and penis in perineal region, it is covered with long hair - optimal age: 3–6 months o very discussable, teacher does not prefer 3 months o hormones important for growth – castration when growing is done o 6-7m, sometimes 9m Canine castration (closed) - anesthetized patient is positioned in dorsal recumbency - hind legs are tied caudally to allow for adequate access for pre-scrotal approach - before proceeding, ensure that both testes are descended, pre-scrotal area has been clipped free of hair and skin has been appropriately scrubbed  - entire scrotum need not be clipped, and doing so may cause excessive post-operative discomfort and self trauma, however reasonably wide region adjacent to prescrotal area must be clipped and prepped to prevent contamination of surgical field - to make initial incision scrotum and testes are grasped and manipulated through drape with left hand, push cranially - one of testes is selected and manipulated cranially such that it can be visualized at midline under skin of prescrotal surgical field - with testis immobilized with left hand, and scalpel blade held in right - midline pre-scrotal incision about size of testis is carefully made over testis down to glistening white of vaginal tunic - once incision is made both hands can be employed to manipulate first testis - testis is pushed out through incision that has been created and fascial attachment between tail of epididymis and scrotum must be broken down, in large dogs this can require cutting this ligament - once tail of testis has been broken down, testis is firmly grasped with dry sponge and pulled cranially - simple, steady and firm traction breaks down surrounding tissues more easily and effectively than stripping with gauze - clamp is placed across cord to define level at which cord will be cut - cord is ligated with 0 or 2-0 multifilament absorbable suture material - second ligature is placed 0,5 cm distal to first - hemostatic forceps are then placed on cord distal to where ligatures have been placed but proximal to where cord will be cut - cord is cut, using previously placed clamp as cutting guide for scalpel blade - free end of cord is inspected and observed for any hemorrhage as it is allowed to return into body cavity - second testis is moved forward and immobilized with one hand as first one was, scrotal septum is incised through skin incision and whole procedure repeated - any subcutaneous dead space can usually be closed with an inverted cruciate suture using 0 or 2-0 monofilament absorbable suture material - well opposed subcutaneous layer helps prevent oozing of small vessels in subcutaneous space and possible postoperative swelling or hematoma formation - skin layer is closed with horizontal intradermal pattern, using 2-0 or 3-0 monofilament absorbable suture material for bigger dogs okay to use one transfixating and one mass ligature, in small dogs only 2 mass no need to suture the inguinal rings (as was taught previously) Feline castration  - anesthetized patient is positioned in dorsal recumbency - hind legs are tied cranially to allow adequate access for scrotal approach - before proceeding, ensure that both testicles are descended and surgical site has been appropriately clipped and prepped - scrotum and small area around scrotum should be clipped to prevent hair from entering the incision - one of testes is selected and immobilized between thumb and first finger of left hand - make a 0.5- to 1-cm incision over each testicle at end of scrotum from cranial to caudal - incise parietal vaginal tunic over testicle and exteriorize testicle - ductus deferens is separated from testicular blood vessels and testis using fingers or scalpel - ductus deferens is tied around testicular blood vessels with 5–6 knots and testis is cut off Castration of male cats (open method) Post–castration complications  - hemorrhage (quite common) o scrotum – no problem? o abdominal cavity – bigger problem o bleeding from wound – if wasn’t closed good enough o less common in cats - wound secretion retention - spermatic cord infection (funiculitis) - omentum prolapse - intestine prolapse Cryptorchism - cryptorchism (kryptorchism) – is abnormal condition, where one or two testes have failed to descend into scrotum and remain in either abdominal cavity or are located in canalis vaginalis - it occurs most frequently in stallions, boars and dogs - abdominal (majorly in dogs, cats, and boars), inguinal (in stallions), or prescrotal (in dogs and cats) cryptorchism are distinguished - cryptorchism is commonly unilateral - testes descend into scrotum 30–40 days after birth ideally - descent of testes is affected by development of gubernaculum - cryptorchism is usually diagnosed in dogs, who are older than 6 months - bilateral cryptorchids are sterile (unilateral are not sterile!) - risk of neoplasias o reason is because testicle needs lower temperature, but if it is in higher temperature and is more prone to get an infection Cryptorchism in small animals - dogs: o Chihuahua o Miniature Schnauzer o Pomeranian o All poodles o Siberian husky o Yorkshire terrier - cats: o Persian cats o Bengal cat o British shorthair - access to prescrotal cryptorchism is achieved similarly to standard castration - testis is pushed out through prescrotal incision and removed using open method - in case of inguinal cryptorchism, testis is fixated through skin and the incision is made directly above testis - testis is removed using open method, if necessary, inguinal canal is sutured and made narrower - castrate the animal fully (some owners might ask for only one but it is congenital→ offspring may have this too)  - abdominal cryptorchism o if it is impossible to palpate testis in prescrotal or inguinal region, laparotomy is performed (ventral median or paramedian) o testis of cryptorchid are usually smaller compared to normal testes o first, sperm duct starting from prostate gland needs to be found, and only then it is possible to find testis (with help of sperm duct, starting from the prostate) o testicular blood vessels and sperm duct are ligated separately o testis is removed - difference between normal and cryptorchism Cryptorchism do them separately, from different wounds since there is bigger risk of bleeding if testicle in abdominal cavity, it does not have tunica vaginalis → not possible to do closed method, do open FEMALE Ovariohysterectomy in small animals - indications: o prevention of estrus and conception o prevention of mammary gland tumors (if done before first heat → prevents tumors, if made later, still can get the tumors) o pyometra prevention o prevention of uterine, ovarian, and vaginal neoplasias o prevention of congenital diseases - dogs and cats do not have menopause (can have puppies in very old age!) Ovariohysterectomy - surgical technique o planned ovariohysterectomy (OHE) is performed during anestrous period (blood vessels are much smaller!!) o incision goes caudally along median line starting from umbilicus o after opening abdominal cavity, omentum is pushed in front of intestines and either right (more difficult, higher because kidneys!!) or left ovary is found (using either fingers or special hook) o suspensory ligament together with blood vessels supplying ovary are ligated and ovary is removed (in dogs might need to be break ligament before removal) o uterine blood vessels are also ligated together with uterine body and are cut through Instruments its okay to remove only ovaries, but can become pyometra still, in dog important to cut in cervix since can leave stump pyometra if the uterus removed2, buttt only cutting ovaries is fine but still risk of pyometra Complications - intraoperative - postoperative - side effects from removing hormonal influence of gonads 24. Phimosis and paraphimosis Phimosis - in case of phimosis, penis is located in preputial bag and, due to narrowed opening, is unable to extrude - phimosis is inability to protrude penis beyond preputial orifice - penis of animal suffering from this condition does not extrude of prepuce during urination, therefore, urination is frequently painful and aggravated - congenital! - surgery is performed under general anesthesia - to enlarge opening, V-shaped incision is made over dorsal surface of prepuce adjacent to orifice - wedge of skin, subcutaneous tissue and preputial mucosa is resected - bleeding vessels are ligated or cauterized and preputial mucosa is sutured to skin with simple interrupted fine sutures Paraphimosis - paraphimosis is condition, where it is impossible to retract penis back into prepuce after it has extruded from preputial ostium, it happens due to changes of prepuce - this condition is also called „Spanish collar“ - condition most frequently occurs in dogs and horses - condition is caused by mechanical or freezing injury of penis - in long–haired dogs and cats, hair around penis may impede its retraction - first, prolapsed and swollen penis needs to be cleaned and rinsed with antiseptic solution - then ventral and dorsal incisions penetrating all layers are made into prepuce, and mucous membrane is attached to skin with sutures - necrotic penis has to be amputated 25. Perineal hernia Perineal hernia - perineal hernias occur when perineal muscles separate, allowing rectum, pelvic, and/or abdominal contents to displace perineal skin - perineal hernia occurs when pelvic diaphragm muscles fail to support rectal wall, allowing persistent rectal distention and impaired defecation - cause of pelvic diaphragm weakening is poorly understood but believed to be associated with male hormones, straining, and congenital or acquired muscle weakness or atrophy - pelvic diaphragm is stronger in female dogs than in males - conditions that cause straining and may predispose to perineal herniation o prostatitis o cystitis o urinary tract obstruction o colorectal obstruction o rectal deviation or dilatation  o perianal inflammation o anal sacculitis o diarrhea o constipation - herniation may be unilateral or bilateral - most herniations occur between levator ani, external anal sphincter, and internal obturator muscles (caudal hernia) - hernial contents are surrounded by thin layer of perineal fascia (hernial sac), subcutaneous tissue, and skin - hernial sac may contain pelvic or retroperitoneal fat, serous fluid, deviated or dilated rectum, rectal diverticulum, prostate, urinary bladder, or small intestine - organs displaced into hernia may become obstructed and strangulated - perineal hernias are common in dogs and rare in cats o they occur almost exclusively in intact male dogs (93%) - dogs with short tails may be predisposed to herniation - breeds most commonly affected are Boston Terriers, Boxers, Pekingese, Collies, Poodles, Dachshunds, Old English Sheepdogs - most perineal hernias occur in dogs over 5 years of age - median age is approximately 10 years - herniorrhaphy should always be recommended - castration is recommended during herniorrhaphy because it has been reported to reduce recurrence - noncastrated dogs have recurrence rate 2.7 times greater than castrated dogs - two most commonly used techniques are o traditional, or anatomic reapposition o internal obturator roll-up, or transposition technique - stool softeners should be given 2 to 3 days before surgery - large intestine should be evacuated with laxatives, enemas, and manual extraction - prophylactic antibiotics effective against Gram-negative and anaerobic organisms should be given intravenously - pelvic diaphragm is composed of paired medial coccygeal and levator ani muscles - sacrotuberous ligament in dog is fibrous band running from transverse process of last sacral and first caudal vertebrae to lateral angle of ischiatic tuberosity rostral to pelvic diaphragm - cats do not have sacrotuberous ligament - sciatic nerve lies just cranial and lateral to sacrotuberous ligament Approach - incision is made over hernia beginning near tail base and extending just ventral to point midway between ischial tuberosity and pubis - incision is curved outward slightly so that it midpoint is directed away from anus - picture: Incision A, traditional perineal herniorrhaphy; incision B, superficial gluteal transposition; 1, purse-string suture in the anus; 2, iliac crest; 3, greater trochanter of the femur; and 4, ischial tuberosity. The incision for the internal obturator muscle transposition should extend 2 to 3 cm ventral to the ischial tuberosity Herniorrhaphy - incise subcutaneous tissue and hernial sac - identify and reduce hernial contents by dissecting subcutaneous and fibrous attachments - biopsy any abnormal structures within hernia (e.g., prostate, masses) - maintain hernial reduction by packing defect with moistened, tagged sponge - identify muscles involved in hernia, internal pudendal artery and vein, pudendal nerve, caudal rectal vessels and nerve, and sacrotuberous ligament Traditional Herniorrhaphy - preplace simple interrupted 0 or 2-0 monofilament sutures using large, curved needle - begin suture placement between external anal sphincter and levator ani, coccygeus, or both muscles - space sutures less than 1 cm apart - as placement progresses ventrally and laterally, incorporate sacrotuberous ligament for secure repair if necessary - to avoid entrapping sciatic nerve, place sutures through rather than around sacrotuberous ligament - direct ventral sutures between external anal sphincter and internal obturator muscle - be cognizant of pudendal vessels and nerves at all times to avoid traumatizing these structures - tie sutures beginning dorsally and progressing ventrally - remove sponge used to maintain reduction before tying last few sutures - evaluate repair; place additional sutures if weaknesses or defects persist - lavage area - close subcutaneous tissues in interrupted or continuous appositional pattern with 3-0 or 4-0 monofilament absorbable suture and close skin in appositional interrupted pattern with nonabsorbable suture Internal Obturator Transposition Herniorrhaphy - incise fascia and periosteum along the caudal border of ischium and origin of internal obturator muscle  - using periosteal elevator, elevate periosteum and internal obturator muscle from ischium - transpose dorsomedially or roll up muscle into defect to allow apposition between coccygeus, levator ani, and external anal sphincter - transect internal obturator tendon of insertion, if necessary, to get adequate coverage of defect - take care to avoid transection of caudal gluteal vessels and perineal nerve - preplace simple interrupted sutures as with traditional technique - begin by apposing combined levator ani and coccygeus muscles with external anal sphincter muscle dorsally - then place sutures between internal obturator and external anal sphincter medially and levator ani and coccygeus muscles laterally Postoperative Care - analgesics should be given as necessary to minimize straining and rectal prolapse. If rectal prolapse occurs, purse-string suture should be placed - cold compresses applied immediately after surgery and two to three times daily for 15 to 20 minutes during first 48 to 72 hours minimize hemorrhage and inflammation - after herniorrhaphy, patients should be monitored for signs of wound infection (i.e., redness, pain, swelling, discharge) - stool softeners should be continued for 1 to 2 months - animal should be fed canned diet high in fiber Complications - fecal incontinence - rectal eversion/prolapse - sciatic paralysis - rectocutaneous fistulae 26. Anatomy of the ear Surgery of ear Surgical anatomy - inner ear – membranous and bony labyrinth, functions for hearing and balance - middle ear – formed by tympanic cavity, connects to pharynx via auditory tube - external ear – formed by auditory meatus and short canal  - pinna - facial nerve exits stylomastoid foramen caudal to ear, courses ventral to horizontal canal close to middle ear Canine ear → - several landmarks for surgery at base of ear - pinna varies greatly in size and shape - cartilage interposed between two skin surfaces - main vessels located along convex surface of ear - main branches of nerves on either surface Feline tympanic cavity → - divided into two compartments by thin, bony septum - postganglionic sympathetic nerves form plexus on structure known as promontory (trauma during surgery – Horner syndrome) Preoperative concerns - assessment of extent & severity of disease (also unilateral/bilateral?) o otoscopic examination o diagnostic imaging (X-R, CT, MRI) - abnormalities should be noted before surgery to avoid confusion with problems caused by intraoperative trauma - thickening, calcification of ear canal – irreversible inflammatory disease - sharp pain response on palpation – middle ear infection? - head tilt – severe pain/otitis media/otitis interna? - neurologic deficiencies/vestibular dysfunction – otitis interna? - facial nerve deficiencies – facial nerve embedded in horizontal canal/serious concurrent middle ear disease? Anesthetic considerations and postOP - preoperative bloodwork (HCT, TP; electrolytes, BUN, Crea in older) - ear surgery often very painful (TECA, canal resections) - hydromorphone and morphine may be preferred over butorphanol and buprenorphine - local anesthetics – bupivacaine hydrochloride (open surgical site) - postoperative constant rate infusions (e.g. FLK) - Elizabethan collar postoperatively - normal wound care, sutures removed in 10-14 days Antibiotic therapy - preoperative antibiotics recommended - severe infection treated with systemic and/or topical antibiotics for several weeks before surgery is performed - cultures of deep tissues taken during surgery are often more useful than preoperative cultures– initial treatment empirical 27. Total ear canal ablation Total ear canal ablation (TECA) - indications: o chronic otitis media (nonresponsive to medical management) o severe calcification of the ear cartilage o severe epithelial hyperplasia extends beyond pinna or vertical ear canal o neoplasia of ear canal o nasopharyngeal/inflammatory polyps (preferably ventral bulla osteotomy) ▪ located in nasopharynx, auditory tube, tympanic cavity, or all three o severely stenotic ear canals o in case lateral ear resection has failed TECA - precautions - potential for serious complications! – this surgery should not be performed: o on animals with mild disease o by surgeons unfamiliar with anatomy of ear - bilateral procedure required – single-stage or staggered surgery may be performed - skin disease (often co-exists) should be treated before surgery is planned - bulla osteotomy in conjunction with TECA must be performed in case of otitis externa and media! (removing avenue for drainage can be disastrous) Suture materials and special instruments - electrosurgery useful (numerous small vessels) - small curettes - rongeurs of various sizes - retractors - culture swabs (both aerobic and anaerobic) Surgical technique 1. animal in lateral recumbency, head elevated; skin prepared for aseptic surgery 2. T-shaped incision, continued around opening of vertical ear canal 3. dissection around vertical canal, continued to level of external acoustic meatus 4. excision of horizontal canal attachment to acoustic meatus (histologic examination?) 5. deep cultures around or just inside external acoustic meatus obtained 6. careful removal of secretory tissue adherent to rim of meatus 7. (lateral bulla osteotomy performed) 8. placement of Penrose drain if desired 9. subcutaneous tissue and skin closed Communication with pet owners - owners’ expectations must be considered before surgery - TECA may diminish hearing and may be considered unacceptable - most owners of dogs with severe, chronic otitis externa or media do not report substantial changes in their animal’s hearing after this procedure (auditory function declines minimally) - pinna deformity can be source of dissatisfaction – single-pedicle advancement flap may be used Modified TECA (single-pedicle advancement flap at base of pinna) - may facilitate upright ear carriage (better cosmetic result) Lateral bulla osteotomy (BO) - tympanic cavity exposed– exudate, secretory epithelium can be removed - offers less exposure to tympanic cavity than ventral BO - preferred in conjunction with TECA (no need to reposition patient) 1. tissue bluntly dissected from lateral aspect of bulla 2. damaging external carotid artery and maxillary vein avoided (they travel just ventral to bulla) 3. caudal aspect of middle ear canal exposed by rongeur 4. curette used to remove infected material (curetting in rostral (dorsal) or rostromedial area of tympanic cavity avoided so as not to damage auditory ossicles or inner ear structures) 5. removal of remaining debris by gently irrigating cavity with saline 6. subcutaneous tissue and skin closed Ventral bulla osteotomy - performed alone or in conjunction with lateral ear resection - technique of choice in cats with inflammatory polyps - bilateral procedures can be performed without need to reposition patient Lateral ear canal resection - increased drainage, improved ventilation - indications: o minimal hyperplasia of ear canal epithelium o small neoplasia in lateral aspect of vertical canal - often not cure – medical management of ear likely necessary for remainder of animal’s life Vertical ear canal ablation - increased drainage, improved ventilation - indications: o diseased vertical canal, normal horizontal canal o neoplasia in vertical canal o otitis externa (unresponsive to medical management) - often not cure – medical management of ear likely necessary for remainder of animal’s life Complications - numerous and occasionally serious - superficial wound infection - vestibular dysfunction - Horner syndrome - deafness - chronic fistulation/abscessation - avascular necrosis of skin of pinna - facial nerve paralysis (usually resolves within few weeks) o loss of blink reflex – artificial tears! - swelling (bilateral procedures) may lead to upper airway obstruction (esp. cats) 28. Aural haematoma Aural hematoma - collection of blood within cartilage plate of ear - cause not well understood – appears to be result of head shaking or scratching at ear (often underlying problem) - initially appear fluid filled, soft, and fluctuant, but eventually may become firm and thickened as result of fibrosis Medical management - needle aspiration (daily?) can be performed, but recurrence likely - use of corticosteroids administered by variety of routes has been described to treat aural hematomas - corticosteroids directly into hematoma cavity following drainage of fluid has successful resolution in over 90% of cases o reported dosages of intralesional corticosteroids ▪ dexamethasone 0,2-0,4 mg in saline q24h for 1-5d ▪ methylprednisolone 0,5-1,0 mL q7d for 1-3w ▪ triamcinolone 0,1-1,0 mL q7d for 1-3w Surgical treatment - numerous techniques described - hematomas should be treated soon after they occur, preferably within several days (to prevent enlargement or fibrosis) - no specific anesthesiologic requirements - goals of surgery:  o removal of hematoma o prevention of recurrence o retention of natural appearance of ear 1. S-shaped incision on concave surface (exposing hematoma from end to end) 2. removal of fibrin clot, irrigation of cavity 3. placement of 0,75-1 cm sutures (2-0/3-0 monofilament) (parallel to major vessels) 4. incision not closed (slight gap allows drainage) 5. placement of light protective bandage over ear; supporting ear over animal’s head 6. removal of bandage and sutures in 14 to 21 days after scar tissue has formed Prognosis and complications - seldom recur if properly addressed and underlying problem successfully treated - cats or dogs with erect or semierect ears may lose carriage of pinna - head bandages must be checked periodically to ensure that they are not too tight (potential necrosis) and are not restricting breathing 29. Dental medicine and surgery ADDITIONAL INFORMATION FROM SLIDES: Rectum, Anus, and Perineum Surgery Outline - anatomy - anal and rectal prolapse - anal sacculectomy - perineal hernia Rectum - rectum begins at pelvic inlet and ends ventral to second or third caudal vertebrae in beginning of anal canal - most of rectum is within peritoneal cavity - short segment continues retroperitoneally before it joins anal canal - retroperitoneal portion of rectum lacks serosal layer, which can have implications for surgical healing - blood supply: o dogs: cranial rectal artery o cats: cranial, middle and caudal rectal arteries Anal canal - anal canal is continuation of rectum to anus and is only 1 to 2 cm long - it is divided into three zones: o columnar zone o intermediate zone o cutaneous zone - columnar zone has series of longitudinal mucosal and submucosal ridges called anal columns - pockets between these columns are anal sinuses, which extend caudally and end in blind Sphincters - internal and external anal sphincter muscles surround terminal rectum and anal canal to control defecation - anal sacs lie between these two muscles on each side of anus - internal anal sphincter is caudal thickening of circular smooth muscle lining anal canal - it is involuntary smooth muscle that works with other muscles of defecation to prevent indiscriminate defecation - it is innervated by parasympathetic branches of pelvic nerve, which are inhibitory - motor fibers from hypogastric nerves are sympathetic to internal anal sphincter - external anal sphincter is large, circumferential band of sk