Surgical Principles and Procedures Notes PDF

1. Halsted’s principles of surgery - Willian Halsted (1852-1922) introduced 10 principles, developed anesthesia (with cocaine) 1. asepsis (no microorganisms that cause disease) 2. gentle 3. blood supply 4. hemostasis 5. tissue trauma 6. time 7. appose tissues 8. moist 9. u...

1. Halsted’s principles of surgery - Willian Halsted (1852-1922) introduced 10 principles, developed anesthesia (with cocaine) 1. asepsis (no microorganisms that cause disease) 2. gentle 3. blood supply 4. hemostasis 5. tissue trauma 6. time 7. appose tissues 8. moist 9. use instruments 10. pretty sutures 2. Incision and excision of tissues - scalpel for sharp incision (usually collagen, poorly vasculated tissue), not for subcut exploration, anatomical dissection for visualization o scalpel blades 1. large (long straight) – no 20 2. small (thinner skin, curving) – no 15 3. small pointed (stab or sharp dissection) – no 11 o grips 1. pencil (contoured) 2. palm (strong, straight) 3. fingertip (best accuracy, long straight) o methods 1. press cut (hollow fluid filled structures) 2. sliding (safe, most common, delicate) skin immobilized with thumb and forefinger, skin tight 3. stab (immobilized with forceps or stay sutures) - scissors for flaccid tissues for blunt or sharp dissection o sharp o blunt ▪ tearing, not cutting, separate tissues ▪ no damage to vessels, nerves ▪ subcut and muscle should separate easily ▪ fingers should be first and best dissecting instrument 3. Hemostasis - simple: injury → vasoconstriction → platelet plug formation → thromboplastin catalyzes prothrombin to thrombin → fibrinogen polymerize → long fibrin strands bound to platelets → hemostatic clot - important since o blocks vision o ideal for bacterial growth → infections o irritate tissues o severe hemorrhage → shock, death - methods o digital pressure (1-5min, swabs can be used, 1st strategy) o hemostats (if 1st ineffective, hemostats crush tissue (→ thromboplastin → coagulation), 5min at site) o packing with swabs (if in deep cavity, pack tightly for 5-10min) o lavage with saline (remove clots and lift tissues, chimney smoke active bleeding, can be cold) o ligatures (discrete bleeding point, grasped with hemostat, after first knot removed) 1. simple ligature 2. transfixing ligature – will not slip, pass through structure before ligation, in OHE and castration 3. mass ligature – e.g. splenectomy o topical hemostatic agents o tourniquet o diathermy (electrosurgery – cut, coagulate, destroy small parts) – for vein or 1-2mm artery 1. monopolar – pencil and electrode, risk of patient burns 2. bipolar – forceps electrode, better control 4. Care and handling of tissues 1. avoid excessive blunt dissection 2. avoid excessive traction 3. handle only necessary tissues 4. separate only planes necessary 5. keep tissues moist 6. avoid exposure to irritant or inflammatory substance (e.g. urine, bile) 7. avoid changes in retractor position 8. do not allow retractors to tear or stretch tissue 9. use appropriate instruments - surgical forceps (toothed) – grasp, prevent sliding, preferred - atraumatic forceps – for fragile tissues (e.g. liver) grasping 5. Closure of tissue planes - goals o restoration of function o eliminate risk of displacement of contents o eliminate dead space o hemostasis o relief of tension o restore epithelial cover - choose number of layers, suture pattern → no excessive handling and too much suture material o no need to close all, some can be combined o should not disturb normal movement of tissue 6. Minimizing operative time - increased time →  o higher infection rate o tissues dry o more handling and thus trauma o more bacterial contamination o longer anesthesia → risk of hypotension, hypothermia, hypoxia, dehydration - common mistakes o poor position o poor understanding of anatomy o fear of cutting wrong o poor visualization o untidy instrument table o not enough hemostasis - simple principles o surgical plan o positioning o review anatomy o practice skills o use assistant o if nervous, take time out o good anamnesis, phys exam with laboratory 7. Surgery of abdominal wall - ventral layers: 1. skin 2. subcutaneous fat 3. external layer of rectus sheath 4. abdominal rectus muscle 5. internal lamina of rectus sheath 6. transverse fascia 7. peritoneum - lateral layers: 1. skin 2. cutaneous trunci muscle 3. deep fascia 4. external abdominal oblique 5. internal abdominal oblique 6. transverse abdominal m 7. transverse fascia 8. peritoneum - vessels o caudal/cranial superficial epigastric o in males external pudendal next to penis - linea alba – fusion of aponeuroses (sheet elastic tendon-like) of external and internal oblique muscles at median ventral abdominal wall, between 2 rectus abdominis o wider, (thicker) in cranial part - natural openings o femoral canal - separated with inguinal ligament from inguinal canal  o inguinal canal – bilaterally symmetrical openings caudoventrally o umbilicus – scar in middle of linea alba o diaphragm openings for aorta, caudal vena cava, esophagus - complications for all: herniation, hemorrhage, suture abscess and reactions, wound infection, edema, septic peritonitis, adhesions, ileus 8. Exploratory laparotomy - laparotomy (surgical approach to abdomen) and celiotomy (entering through midline) o upper midline – from xiphoid to umbilicus ▪ stomach, pancreas, liver o lower midline – from umbilicus to pubic symphysis ▪ neutering o paramedian – off midline (through rectus m) ▪ if linea alba already scar, e.g. repeated caesarian o paracostal – parallel with last rib ▪ liver, diaphragmatic hernia - ventral laparotomy in small animals o indications: exploratory laparotomy, surgeries on abdominal organs o anesthesia: general anesthesia + regional and local (lidocaine, bupivacaine) o surgical site preparation: ▪ hair is clipped from xiphoid region to pubic bone ▪ surgical site is prepared in general aseptic rules o equipment: ▪ general set of surgical instruments, retractors (ex. Balfour retractor) ▪ reabsorbable synthetic suture, monofilament or multifilament (not to skin) o steps: 1. incision front or behind umbilicus 2. cut trough skin, subcutaneous tissue and external lamina of rectus sheet 3. linea alba exposed → make a stab incision with scalpel (let organs fall down) 4. insert thumb forceps with the tips placed caudally to lift upward the linea alba and make a cranial to caudal incision 5. abdominal exploration 6. closure: o 1. layer simple continuous sutures placed on external lamina of rectus abdominis o 2. layer continuous sutures closes subcutaneous connective tissue 3. layer skin closed with intra-dermic continuous suture / simple interrupted - exam question: should we stitch peritoneum when closing the abdominal wall? → answer: no, because painful to stitch, can inflame, heals rapidly, no strength added so mainly other structures 9. Parts of abdominal wall hernia - hernia – protrusion of internal organ through defect in wall of abdominal cavity (normal place), seen as subcutaneous swelling - true hernia – protrusion of abdominal content through existing or potential opening in body wall that gas become pathologically enlarged or disrupted o usually congenital - false hernia – protrusion of abdominal contents through rupture of body wall o usually traumatic - can be located for example o umbilical, scrotal, abdominal, inguinal, perineal, femoral, diaphragmatic - parts of abdominal wall hernia o hernial ring – actual defect in abdominal wall o hernial sac (external and internal) – surround hernia contents, NOT in false hernia o hernial content – organs or structures permitted through ring (fat, intestinal loop, omentum) - reducible hernia - small, soft, nonpainful, can be gently manipulated back into abdomen - irreducible hernia – firm, tissues not freely movable 10. Umbilical hernia - on umbilical ring during fetal development does not either grow over or gets ruptured during birth o breed predisposition: basenji, pointer - surgery of reducible umbilical hernia o equipment: 1. general set of instruments 2. non-resorbable synthetic suture o steps if small, contains only fat: 1. animal is fixed on its back or in dorsal position, surgical site is cleaned and disinfected with general aseptic rules 2. incision is made directly over hernia 3. internal hernial sac is inverted 4. hernia ring is closed without debriding (tuoreistus) of edges of ring 5. simple interrupted pattern (also absorbable can be used) o steps if large or inflamed hernia 1. animal is fixed on its back or in dorsal position, surgical site is cleaned and disinfected with general aseptic rules 2. incision is made around hernia 3. through surgical wound → internal hernia sac is separated from external one using fingers (scissors or scalpel also) 4. necessary to expose 1–2 cm of hernia ring around abdominal wall 5. internal hernial sac is reduced into abdominal cavity 6. edges of hernial orifice are joined with simple interrupted suture, so internal hernial sac remains intact and abdominal cavity closed 7. skin is closed with interrupted suture o irreducible hernia 1. with fat/omentum → ligated and removed → ring closed 2. with intestines/organs → ring enlarged cranially and caudally along linea alba o squeezed hernia 1. if organs inside, check viability → if necrotic, remove - AB used for irreducible or squeezed hernia - for young animals with reducible/fat containing ok to wait until neutering 11. Inguinal hernia - omentum, intestine, bladder or uterus through inguinal canal, more frequent in small dogs o constipation, obesity, gestation predispose - congenital, inherited, traumatic - unilateral common on left, can be also bilateral - can be o direct – contents protrude through inguinal canal near vaginal process (more in female) o indirect – contents protrude through vaginal process to vaginal cavity (males), and also form scrotal hernia - inguinal canal o in ventral/anterior abdominal wall o pubic artery, vein and nerve run through, additionally 1. in males spermatic cord and vessels, cremaster muscles 2. in females round ligament of uterus o superficial inguinal ring – slit-like external entrance going posteriorly, formed by external abdominal oblique aponeurosis and inguinal arch o deep inguinal ring – internal entrance to inguinal canal, formed by internal abdominal oblique, inguinal arch, and transverse fascia - inguinal hernia affected by anatomic, hormonal and metabolic factors - steps of inguinal hernia surgery o equipment 1. slowly resorbable / non-resorbable monofilament for hernia 2. reabsorbable for subcutis, skin 1. prepare site, know anatomy 2. incision is made from above superficial inguinal ring till internal hernial sac 3. internal hernial sac is fixed using fingers and bluntly dissected along its whole length till hernial orifice 4. internal hernial sac is cut open and hernial contents is reduced back to abdominal cavity 5. empty internal hernial sac is ligated in its neck, amputated and hernial orifice is closed with interrupted suture (leave opening in caudomedial part since external pudendal vessels and genitofemoral nerve are there) 6. subcutaneous tissue closed using synthetic resorbable suture material, essential not to leave any hollows, as tissue proliferation level in this region is very high 7. skin is closed with intra-dermic suture or simple interrupted suture 12. Scrotal hernia - usually small intestine goes through inguinal canal to scrotum into either vaginal cavity (more) or outside parietal lamina of tunica vaginalis, most frequently in swine but rare - congenital, usually reducible - surgery fast after diagnosis, risk of adhesions - steps for surgery: 1. incision is made above inguinal canal 2. hernial contents is reduced through inguinal canal into abdominal cavity (if necessary, internal hernial sac is opened)  3. internal hernial sac (parietal lamina of tunica vaginalis) is narrowed in hernial neck area close to hernial orifice (inguinal canal) using mattress suture 4. cranial part of inguinal canal is closed with slowly resorbable suture material - if done with castration (as usually): 1. internal hernial sac opened, hernial contents reduced 2. testicle is massaged out through the scrotum 3. ligament of epididymis is cut through 4. blood vessels and sperm duct are ligated and cut through 5. internal hernial sac is ligated in its neck, removed 6. inguinal canal closed with interrupted suture - femoral hernias extremely rare, usually abdominal fat with femoral artery and vein 13. Topographic anatomy of gastrointestinal system - stomach o continuation of esophagus in cranial abdomen o shape depends on fulfillment 1. empty/moderate → V-shape 2. filled → spherical o parts for anatomy 1. greater and lesser curvatures 2. parts: cardia, fundus, body, pylorus (on left in VD view) fundus least vascularized, only storage 3. ligaments: hepatogastric, hepatoduodenal, gastrosplenic, gastrophrenic 4. blood: celiac artery divides to spenic, left gastric, hepatic arteries EXAMM gastroepiploic artery between great curvature and spleen → do not ligate in splenectomy o structure of wall 1. mucous membrane 2. submucosa (strongest) 3. muscular 4. serous membrane - omenta – ligaments or mesenterial membranes for abdominal organs, with intense blood and lymph supply, contains fat o holds organs in place, blood deposit, thermal insulation, produce and reabsorb abdominal fluid, regulate BP - intestines: duodenum → jejunim → ileum → cecum → colon → rectum o layers: 1. mucous membrane 2. submucosa 3. circular muscle 4. longitudinal muscle 5. serosa o rectum – begins in pelvic inlet, ends ventral to 2-3rd caudal vertebra → anal canal most inside peritoneal cavity, retroperitoneal part lacks serosal layers cranial rectal artery (in cats also middle and caudal) o anal canal – 1-2cm long with columnar, intermediate and cutaneous zone o internal (smooth muscle) and external (skeletal muscle) anal sphincters  o anal sacs between those muscles 14. Main principles of gastric and intestinal surgery - main principles of gastric surgery o less bacteria than in elsewhere in GIT o perioperative AB, depending on case o access 1. common: ventral medial laparotomy form sternal manubrium to umbilicus 2. Balfour retractors o minimizing contamination 1. stomach isolated from wound with large moist sterile tampons 2. fixating sutures used 3. different instruments for clean and clean-contaminated parts (as stomach opened → clean-contaminated) 4. local lavage with NaCl (keep clean) o closing gastric wound 1. 1st layer: mucous membrane closed with simple continuous 2. 2nd layer: submucosa, muscular, serous membrane closed with intestinal suture (e.g. Cushing, Connell, Lembert) 3. absorbable monofilament used (e.g. PDS) - main principles of intestinal surgery o fluid therapy 1. usually fluid-electrolyte balance disorders, dehydration (hypokalemia can lead to heart problems) → rehydrate o SI has lot of bacteria, if mucous membrane damaged, may cause infection → preventive use of AB 60min before surgery (1st generation cephalosporin) o assessment of viability: pink/red, peristalsis, pulsation of mesenterial bv (biopsy may be needed) o suture material: 1. reabsorbable monofilament (PDS) or nonabsorbable (nylon), also possible with multifilament 2. submucosa strongest layer – close well to heal well better contact in edges with one layer suture 3. use cushing, simple continuous or schmieden 15. Gastrotomy - indications: o foreign body removal, ulcers, neoplasia (take all 4 layers) - preparation: o 24h fasting o fix dehydration o preoperative antibacterial therapy (2h before) - materials: o absorbable monofilament - steps: 1. animal is placed and fixed on its back 2. abdominal wall is opened along median line between xiphoid and umbilicus  3. omentum is carefully pushed to side and stomach is taken out of wound to greatest possible extent 4. fixating sutures are placed at both ends of the incision in order to prevent retraction (only through serosa) 5. wound and area around it are covered with sterile sponges to avoid contamination 6. incision is made between greater and lesser stomach curvatures in less vascularized place 7. gastric contents is removed and gastric wall is examined 8. gastric wall is closed with two–layer suture a. mucous membrane with simple continuous b. submucosa, muscular layer and serous membrane closed with intestinal suture, e.g cushing 9. fixating sutures are removed 10. stomach is carefully reduced back to abdominal cavity - after: o start feeding 4-12h o gastroprotectors o AB 16. Pyloromyotomy and pyloroplasty - aim to increase pylorus diameter, surgical solution to pyloric mucosal hypertrophy or pyloric stenosis (careful since surgical errors bad) - Fredet- Ramsted pyloromyotomy steps o least complicated, temporary (since incision will heal and muscular layer grows back), not used so much 1. pylorus is held between index finger and thumb of non-dominating hand 2. longitudinal incision penetrating serous membrane and muscular layer is made into less vascularized area of ventral pylorus 3. mucous membrane and submucosa should remain intact (in case of injury, it is closed with sutures) 4. it is important to make certain that incision has fully cut through muscular layer and exposed mucous membrane, 2-3cm long - Heineke-Mikulicz pyloroplasty steps o simple, often used, suture material: reabsorbable monofilament 1. longitudinal incision is made into pyloric ventral surface 2. incision goes through all layers 3. fixating sutures are placed in middle of incision on both sides of wound 4. wound is closed transversally with simple continuous suture - Y-U pyloroplasty steps o widens most lumen 1. longitudinal incision (leg) in ventral part of pylorus 2. first incision only penetrates through serous membrane 3. incision goes further and splits in two incisions going parallel to greater and lesser curvatures (shoulders) → Y–shape incision emerges a. corner between „shoulders“ cannot be too sharp and narrow, can result in necrosis b. all parts of Y-shape incision (leg and shoulders) should be of same length 4. when first incision through serous membrane is made → following incisions go deeper and penetrate through muscular level and mucous membrane  5. severely hypertrophied (enlarged) mucous membrane can be removed 6. closing of top of gastric wall starts at duodenal end of incision 7. incision is closed with simple interrupted suture 8. so, Y – shape incision turns into a U – shape one, suturing continues in both directions 17. Enterotomy, intestinal resection and anastomosis - enterotomy – opening of intestine - enterectomy or intestinal resection – removal of part of intestine o for foreign bodies, neoplasia, invaginations - enteroplication – fixating parts of intestine to another - enteropexy – fixating intestine to abdominal wall - intestines: duodenum → jejunim → ileum → cecum → colon → rectum - layers: o mucous membrane o submucosa o circular muscle o longitudinal muscle o serosa - obstructions: changes in fluid balance (can be also in ileocolic place with sand) o in x-ray measure 5th lumbar → SI lumen should not be 2x that o torsion is by the base (around), volvulus is by the side (around own axis) - enterotomy steps 1. part of intestine containing foreign body is taken out through wound and isolated from wound with sterile tampons 2. 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 3. intestine is opened longitudinally on left side of mesentery above foreign body (scalpel no 11) 4. length of incision should allow for easy removal of foreign body 5. if necessary, incision is lengthened using Metzenbaum scissors 6. after removal of foreign body, edges of enterotomy wound are cleaned and closed with one–layer simple continuous suture - intestinal resection 1. raise intestinal segment out of wound, isolate from rest of abdomen with tampons 2. mesenterial vessels supplying this segment are ligated 3. cut mesentery, save as much as you can 4. doyens intestinal clamps to intestine 5. remove 3-4mm of healthy intestinal wall with pathological segment ▪ keep mesenterial edge longer than antimesenterial edge - different methods for anastomosis o end-to-end preferred 1. ends between clamps next to one another with open ends towards surgeon 2. starting from mesenterial edge, intestines are closed with simple interrupted 3. intestinal edges closed on both sides using simple interrupted or continuous suture 4. mesentery closed with simple continuous 5. check for blood flow, find vessels  o side-to-side if diameter significantly different, not so common 1. both ends of intestine closed with two layer suture (simple continuous, cushing) 2. ends placed next to another along peristalsis 3. empty intestinal contents away, fixate with intestinal clamps 4. joined close to mesentery with 4-8cm continuous suture through serosa and muscular layers o stapling intestinal ends (with GI anastomosis and thoracoabdominal stapler) quick and simple, expensive 1. intestinal ends side by side with antimesenterial edges 2. GIA stapler in those endings and antimesenterial edges pressed together → create connection 3. fixating sutures to both ends 4. TA stapler placed on ends, connecting those - linear foreign body o start from mouth, do not pull, see if string there o then stomach, then intestines o several enterotomy incisions - enteroplication – fixing one intestinal part to another o prevent invaginations (usually in jejunum and ileum) o placed side to side with no sharp turns o simple interrupted between mesenterial and antimesenterial, not through mucosa 18. Topographic anatomy of urinary system - cystotomy – surgical opening of urinary bladder - cystectomy – surgical removal of part of urinary bladder - cystolithectomy. surgical removal of urinary bladder stones - urethrotomy – surgical opening of urethra - urethrostomy – creation of permanent urethral fistula - Urinary bladder o pear shaped, distensible balloon of smooth muscle o place depends on fulfillment, but in ventral abdominal wall (can extend to umbilical region if too much) o parts: neck, body, apex, vesical trigone (ureter openings, internal urethra orifice) o ligament: median vesical (attach to perlvic floor), paired lateral vesical o blood: cranial, middle, caudal vesical a o layers: serosa, muscular, mucous membrane o nerves: hypogastric, pudendal - urethra o urine leaves bladder through this o layers: external membrane, muscular, mucous membrane o in male divided to: prostatic, membranous and penile urethra ▪ bulbospongiosus, corpus cavernosus, bulbus (in dogs), os penis 19. Main principles of urinary surgery - healthy bladder incisions heal quickly, mm only 5d o entire wall 14-21d until normal strength - 75% of wall can be remover → regenerates in 3-4m - resorbable (3-0→5-0) monofilaments used (no non absorbable since can cause stones) o round, atraumatic needle - suture does not penetrate mucous membrane - one layer simple continuous - AB not usually needed (but if longer surgery then yes) o if catheter or already bacteria → AB (amox+clavu, cephalosporins) - recovery of urethra o optimal condition mm only 7d to complete recovery o risk of edema, catheter prevents structures o fast absorbable monofilaments used 20. Cystotomy - indications: removal of stones (more in males), tumors, treatment of rupture - steps 1. caudal median laparotomy, in male dogs incision continued laterally from prepuce 2. at beginning, surgeon checks whether there is any free urine in abdominal cavity 3. urinary bladder is carefully palpated, if it is full – it is punctured using syringe 4. before opening, bladder is taken out of wound and isolated using large tampons and sheets to avoid abdominal contamination 5. fixating sutures placed 6. incision into ventral or dorsal wall is made using scalpel nr 11 7. incision is close to apex and away from ureters and urethra, in between blood vessels incision is lengthened using scissors 8. all layers are penetrated 9. ventral cystotomy allows for more efficient examination of vesical trigone region 10. mucous membrane needs to be handled very carefully!, do not damage vesical trigone! 11. bladder stones carefully removed using surgical spoon 12. catheter is retrogradely (takautuvasti) inserted into urethra 13. urinary bladder is rinsed using NaCl 0.9% solution (at least 3x) 14. biopsy of mucous membrane sample is conducted as part of bacterial examination 15. close with one-layer suture – simple continuous suture must not penetrate mucous wall! 16. after closing, bladder is reduced back into abdominal cavity 17. laparotomy wound is closed with three–layer suture! - afterwards catheter inside bladder for 2-3d, bladder rinsed (BUT often not left inside after removal of stones) 21. Urethrotomy and urethrostomy - urethrotomy: treatment of urethral obstructions o can be prescrotal, scrotal, perineal - prescrotal urethrotomy (stones in distal urethra) o fast-absorbable monofilaments (rapid) 4–0, 5-0 o steps  1. insert sterile catheter into urethra till place of obstruction 2. animal is placed on its back 3. cutaneous incision of 1–2 cm is made above obstruction between penile bone and scrotum, incision continues till retractor muscle of penis 4. retractor muscle is visualized, mobilized and pushed laterally to get access to urethra 5. penis is fixated using fingers 6. urethra is normally 3–4 mm wide, pink, surrounded by white cavernous bodies 7. urethra is opened using scalpel and stones are carefully removed 8. urethra is rinsed using NaCl 0.9% solution 9. catheter is inserted further into bladder 10. urethra is left to gradually recover (in this case, catheterization is necessary) or closed with simple continuous suture 11. wound is closed with two–layer suture: subcutaneous tissue is closed with simple continuous suture (urethra can be also closed too) skin is closed with subcuticular suture - perineal urethrotomy (stones in isthmus urethra, urethra bends around ischial arch) 1. animal is in prone position, tail is raised and fixated in this position 2. anus is closed with tobacco–pouch (purse string) suture 3. sterile catheter is inserted into urethra till obstruction place 4. skin and subcutaneous tissue are cut through with scalpel in middle between anus and scrotum 5. retractor muscle is visualized, mobilized and pushed laterally 6. paired bulbospongiosus muscles are separated from one another in their adhesion point 7. corpus spongiosum is incised and urethra opened 8. urinary stones are removed, urethra is rinsed 9. catheter is inserted into bladder 10. urethra is left to gradually recover or is closed using resorbable monofilament (4–0, 5–0) with simple continuous suture 11. corpus spongiosum is closed with simple continuous suture using synthetic resorbable suture material (4 – 0) 12. wound is closed with two–layer suture: bulbospongiosus muscles and subcutaneous tissue are closed with simple continuous suture skin is closed with subcuticular suture - urethrostomy: stone removal, stricture, neoplasia, trauma, penis amputation → “making new urethral opening” o can be prescrotal, scrotal, perineal, prepubic - prescrotal urethrostomy o similar to urethrotomy o difference is that in this mucous membrane is attached to skin with simple interrupted suture, resorbable monofilament starting from caudal corner o length of incision is 6-8x diameter of urethra - scrotal urethrostomy (preferred since wider and superficial urethra) o started with castration via scrotum o othervise similar to prescrotal but incision site  o then incision to urethra above catheter o mucous membrane attached to skin - perineal urethrostomy (only if no other possibilities since thick cavernous tissue → hemorrhage) o similar to perineal urethrotomy o length if insicion 4-6cm, urethral 1.5-2cm o mucous membrane attached to skin with interrupted o mostly used in cats! (cut some muscles to success so not puling urethra) - penis amputation 1. penis is dissected free of underlying and surrounding tissues 2. reflect penis dorsally and to either side to unable ischiocavernosus muscles to be isolated and sectioned 3. enable penile ligaments, trim retractor penis muscle away from its dorsum 4. make longitudinal incision into dorsal penile urethra and amputate distal penis 22. Topographic anatomy of male/female genital organs - 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 o catsration indication: sexual urge suppression, prevention of escape, therapeutic (inflammation of testes, scrotum, prostate etc), prevention of congenital disease adrenal glands produce testosterone also! o testis – paired ovoid organs in scrotum, produce male hormones, gametes o scrotum – protrusion of abdominal wall, divided to ▪ skin – thin, pigmented ▪ tunica dartos – omnidirection smooth muscle extending to skin, fibers, wrinkle scrotum if thermal or mechanical irritation o layers 1. skin 2. tunica dartos 3. external spermatic fascia 4. cremaster muscle (adheres to vaginal tunic) 5. internal spermatic fascia???? 6. vaginal tunic (peritoneum, thickest) parietal lamina visceral lamina (cover spermatic cord, testis) o area between visceral and parietal lamina is canalis vaginalis up and cavum vaginale at level of testis o blood: testicular, external pubic, cremasteric vessels o innervation: caudal mesenteric plexus, iliohypogastric, ilioinguinal, genitofemoral nerves o ligaments: proper ligament, epididymal tail gubernaculum in young pull testis out o spermatic cord: vessels, nerves, deferent duct o epididymis: head, body, tail - female  o indications, prevent: estrus, mammary tumors (if done before 1st heat), pyometra, neoplasia, congenital disease o ovaries – in abdominal cavity, caudally from kidneys, close to apex of uterine horn hang on mesovarium bursa ovarica surrounds (in dogs contain fat and cover completely, in cats fo fat and cover only laterally) ligaments: utero-ovarian ligament, suspensory ligament of ovary o in dogs no vessels in suspensory ligament, in cat vessels in both o vessels: ovarian artery, uterine artery o uterus tubular organ with horns, body, cervix 3 layers: serous membrane (perimetrium), muscular (myometrium), mucous membrane (endometrium) ligaments: mesometrium (to dorsal wall), round ligament of uterus (to inguinal ring), intercornual engalt o mesometrium, mesosalpinx, mesovarium → broad ligament of uterus cervix and body short in carnivores blood: uterine artery from pubic artery, ovarian and vaginal a. 23. Male/female neutering surgery - good anesthesia with local anesthesia o infiltration of parenchyma of testis with lidocaine and as pulling out, incision line - castration of dogs and cats o testes small, longitudinal axis diagonally o optimal age: 3-6 months (when growing is over → so usually later) - male dog closed (open preferred) o scrotum opened to parietal lamina of vaginal tunic, prepared off surrounding tissues o vaginal tunic prepared off surrounding tissue, testis remain inside and spermatic cord and testis covered with vaginal tunic removed (cavum vaginale closed) o used in pathologies (e.g. hernia, prolapse, necrosis, inflammation) 1. dorsal recumbency 2. hind legs tied caudally, to access for pre-scrotal approach 3. ensure that both testicles are descended, clip area prescrotal area, prep aseptically 4. scrotum and testes grabbed and manipulated through drape 5. one testicle selected and manipulated cranially such that it can be visualized at midline under skin of pre-scrotal surgical field 6. incision in midline about the size of the testis is carefully made over the testis TO white of vaginal tunic (through skin, fascia, cremaster muscle) 7. testis is pushed through incision 8. fascial attachment between tail of epididymis and scrotum broken down (in large dogs – cutting) 9. once tail has been broken → testis firmly grabbed and pulled cranially 10. clamp is placed across cord to define level at which cord will be cut 11. cord is mass ligated with 0 or 2-0 multifilament absorbable suture (in large dogs can be transfixing ligature) 12. second ligature placed 0,5cm distal to first 13. hemostatic forceps placed on cord distal to ligatures but proximal to where cord will be cut  14. cord is cut 15. free end of cord inspected for any bleeding → return to body cavity 16. repeat same for second testis, incision through scrotal septum 17. any subcutaneous dead space can be closed with inverted cruciate suture using 0 or 2-0 monofilament absorbable suture material 18. subcutaneous layer closed well (helps prevent oozing and possible post-operative swelling/hematoma formation) 19. skin layer closed with horizontal intradermal pattern, 2-0 or 3-0 monofilament absorbable suture material - feline castration (open method) 1. patient in dorsal recumbency 2. hind legs tied cranially to allow adequate access for scrotal approach 3. check that testes are descended, area is clipped and prepped 4. one of testes is selected and immobilized between thumb and first finger of left hand 5. make a 0,5 to 1 cm incision over each testicle at end of scrotum from cranial to caudal 6. incise parietal vaginal tunic over testicle and exteriorize testicle 7. ductus deferens is separated from testicular blood vessels and testis using fingers or scalpel 8. ductus deferens is tied around testicular blood vessels with 5-6 knots and testis is cut off (ALSO other methods: ligature with material or knot around own axis) - male dog open method o scrotal wall and parietal lamina of vaginal tunic are cut through, cavum vaginale opened, testicle popped out, break gubernaculum, testis removed o used if no pathology in testes or inguinal canal - complications: hemorrhage, wound secretion retention, spermatic cord infection, omentum or intestine prolapse - cryptorchism o one or both testes failed to descend to scrotum and remain in abdominal cavity or canalis vaginalis (dog, stallion, boar) bilateral are sterile, unilateral not → castrate wholy! dogs: chihuahua, poodles cats: persian, engal o abdominal, inguinal, prescrotal o usually testes descend to scrotum 30-40d after birth (gubernaculum) o risk of neoplasia (since higher temperatures → more prone to infection) o prescrotal – removed similarly to open standard castration o inguinal – incision above testis, inguinal canal can be sutured smaller, otherwise open normal method o abdominal – find from sperm duct from prostate, ligate blood vessels and sperm duct separately → remove EXAM → if testicle in abdominal cavity, no tunica vaginalis → only open method possible - female ovariohysterectomy (OHE) o performed during anestrus (since blood vessels much smaller) o okay to remove only ovaries but can become pyo still, cut to cervix 1. incision goes caudally along median line starting from umbilicus  2. opening abdominal cavity 3. omentum is pushed side in front of intestines 4. right (higher, harder) or left ovary is found (using fingers/spay hook) 5. suspensory ligament together with blood vessels supplying ovary are ligated and ovary is removed (in dogs might need to break the ligament before removal) 6. uterine blood vessels are also ligated together with the uterine body and cut through 24. Phimosis and paraphimosis - phimosis penis is in preputial bag and narrowed opening does not let out there o inability to protrude penis beyond preputial orifice o not even in urination → painful, gets worse o congenital o steps 1. V-shaped incision is made over dorsal surface of prepuce, joining orifice 2. wedge of skin, subcutis and mucosa taken out 3. preputial mucosa sutured to skin with simple interrupted sutures - paraphimosis o impossible to retract penis into prepuce after extruded from preputial ostium due changes of prepuce (most frequent in dogs and horses) o caused by mechanical or freezing injury to penis, hair may also impede retraction in long haired animals o steps 1. prolapsed, swollen penis cleanse and rinsed with antiseptic solution 2. ventral and dorsal incision through all layers are made to prepuce 3. mucous membrane attached to skin with sutures 4. necrotic penis is amputated 25. Perineal hernia - occurs when perineal muscles separate, allow rectum, pelvic or abdominal contents to displace perineal skin o pelvic diaphragm muscles (medial coccygeal, levator ani) fail to support rectal wall, allow persistent rectal distension and impair defecation (pelvic diaphragm stronger in females) sacrotuberous ligament rostral to pelvic diaphragm (not in cats) sciatic nerve cranial and lateral to that o cause not understood but connected to male hormones, straining and congenital or acquired muscle weakness or atrophy conditions that cause straining and may predispose to hernia → prostatitis, cystitis, UT obstruction, rectal dilation, constipation o unilateral or bilateral o most between levator ani, external anal sphincter, internal obturator muscle o surrounded by perineal fascia, subcutaneous tissue and skin o may contain fat, serous fluid, rectum, rectal diverticulum, prostate, urinary bladder, SI may become obstructed, strangulated o common in intact male dogs  short tail boston terrier, bower older dogs o herniorrhaphy recommended with castration (no reoccurrence) o stool softeners for 2-3d before o prophylactic AB - steps o incision over hernia beginning near tail base to midway of ischial tuberosity and pubis, curved outward a bit o herniorrhaphy 1. incise subcutaneous tissue and hernial sac 2. identify and reduce hernial contents by dissecting attachments 3. take biopsy of abnormal material inside hernia 4. reduce the contents with sponges 5. identify the muscles involved in hernia, internal pudendal vessels, pudendal nerve, caudal rectal vessels and nerve, sacrotuberous ligament o traditional herniorrhaphy 1. simple interrupted suture with 0 or 2-0 monofilament, large curved needle 2. start dorsally and suture between external anal sphincter and levator ani or coccygeus or both 3. sutures less than 1cm apart 4. when going ventrolaterally, incorporate sacrotuberous ligament (go through not around because ischiadic nerve) 5. suture external anal sphincter and internal obturator 6. avoid pudendal vessels and nerves 7. remove sponge used to maintain reduction before tying last few sutures 8. evaluate repair and add more sutures if needed 9. lavage area 10. close subcutaneous tissues with interrupted or continuous 3-0 or 4-0 monofilament absorbable 11. close skin with interrupted nonabsorbable o internal obturator transposition herniorrhaphy 1. incise fascia and peritoneum along caudal border of ischium and origin of internal obturator muscle 2. elevate periosteum and internal obturator 3. move dorsomedially or roll up muscle into defect, between coccygeus, levator ania and external anal sphincter 4. if needed transect obturator tendon 5. avoid caudal gluteal vessels, nerve 6. simple interrupted sutures as in traditional - after surgery normal care + stool softeners for 1-2m 26. Anatomy of ear - inner ear – membranous and bony labyrinth, functions in 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 (varies in dogs) – cartilage interposed between skin surfaces - fascial nerve exits stylomastoid foramen caudal to ear, goes near middle ear - anatomy o tympanic membrane (malleus touches) o auditory ossicles: stapes, incus, malleus o tympanic cavity inside tympanic bulla o semicircular canals o bony labyrinth - canine ear o main vessels along convex surface o main branches on both surfaces o vertical and horizontal canal - feline o tympanic cavity divided into two with bony septum o promontory has nerves in there - preop o assess severity, extent (otoscopy, x-ray/CT/MRI) o can be thickening of canal, sharp pain, head tilt, neurologic deficiencies, facial nerve deficiencies o very painful op so use morphine, LA with bupivacaine o preop AB recommended o culture of deep tissues in surgery 27. Total ear canal ablation (TECA) - indications o chronic otitis media, severe calcification of ear cartilage, severe epithelial hyperplasia, neoplasia, polyps, stenotic ear canal - precautions o serious complications (not in mild disease, good surgeon) o bilateral procedure may be required o skin disease treated before o lateral bulla osteotomy (BO) if otitis externa and media (otherwise trapped there) - materials and instruments o electrosurgery o curettes o rongeurs (for bone) o retractors o culture swabs - TECA 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 - communicate with owners (expectations, may affect hearing, pinna deformity) - modified TECA for upright ear carriage (flap at base along ear margins but smaller) - lateral BO technique (exudate and secretory epithelium can be removed) 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 BO o alone or with lateral ear resection o cats with inflammatory polyps o bilateral procedure with no reposition of patient - lateral ear resection (only vertical canal removed, all other stay) o improve drainage, ventilation o used if: minimal hyperplasia in ear canal, small neoplasia in vertical canal o often no cure (medications for rest of life) - vertical ear canal ablation o improve drainage, ventilation o used if: disease in vertical canal, neoplasia, otitis externa o often no cure - complications o numerous and serious o infection o vestibular dysfunction o horner syndrome o deafness o chronic fistulation, abcessation o avascular necrosis in pinna o facial nerve paralysis 28. Aural hematoma - collection of blood within cartilage plate of ear - cause not well understood (head shaking or scratching) - appear fluid filled, soft and fluctuant → firm and thickened after fibrosis - medical management o needle aspirations, recurrence likely o corticosteroids into cavity after drainage (90% success), e.g. dexamethasone - surgical treatment o different techniques o soon after occurring, within days to prevent enlargement of fibrosis o goals: removal of hematoma, no recurrence, natural appearance of ear o steps  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 o seldom recur if good treatment and underlying problem treated o may lose carriage of pinna o head bands checked, not too tight