Surgery E1 SG PDF

Surgery E1 SG Historical Figures Aristotle: grandfather of comparative medicine that investigated similarities and differences btw species. Described the absence of the gallbladder in horse Andreas Vesalius: father of modern human anatomy Ambroise Pare: treatment of gunshot wounds in horses, lig...

Surgery E1 SG Historical Figures Aristotle: grandfather of comparative medicine that investigated similarities and differences btw species. Described the absence of the gallbladder in horse Andreas Vesalius: father of modern human anatomy Ambroise Pare: treatment of gunshot wounds in horses, ligation in order to control hemorrhage Joseph Lister: antiseptic surgery by using concepts from Louis Pasteur Morton: dentist that was the first to use ether (highly flammable) Roentgen: german physicist that discovered radiographs Thomas edison: fluoroscope (radiograph that lights up to allow for visualization) in 1896 John hunter: scientific method approach to medicine and surgery Halsted: change of surgical approach from fast to meticulous in the early 1900s using hemostasis, local anesthetics, and emphasis on patient care Cesarean Section First time = 272 BC ○ High mortality if done on live mother Increased survival with closed uterus Low low mortality of both dam and offspring Patient Prep Clipping with 40 blade At least 20 cm on either surgery side * Ophthalmic and dental procedures with NO PREP * Dirty scrub with clorohex and alcohol Once clamp has penetrated drape = CONTAMINATED Surgeon getting “ready” order 1) Open table drape (open outwards) 2) Open outer pack and drop inner layer onto table (sterile) 3) Open suture and scalpel onto table  4) Open gown and gloves onto sterile gown* 5) Make sure table adjusted correctly, patient adjusted, table adjusted, and everyone is ready for you to scrub 6) Go sterile scrub and put on sterile gloves and gown 7) Open pack 8) Drape and clamp 2 rounds of towl clamps 9) Fenestration 10) Organize instruments (handles towards surgeon) 11) Cut! Sterile areas Hands above elbows “Prayer” position Waist and above is sterile Surgery report Animal positioning ○ ex) dorsal recumbency in V trough Area prepared and how it was prepared ○ ex) ventral abdomen from xiphoid process to pubis using 4% chlorohex and alcohol Approach with location, length, and instruments used ○ ex) 20cm incision with #10 scalpel blade Major findings with what was explored and pathology Major procedures in order ○ ex) ligation with size of suture, transection with instrument used, blunt and sharp dissection, and implants placed (EXACT numbers, sizes) Incision closure ○ ex) layers, patterns, sutures, needle type Incisional dressings ○ ex) incision dressed with Telfa pad with Kling gauze Anesthesia recovery and/or complications Suturing Goal: maintain apposition (holding tissue together) until wound’s tissue strength returns ~ tension strength of suture should correspond to tissue healing time (sutures REMOVED post healing) Suture materials classified based on… 1) Structure (monofilament vs. multifilament) 2) Behavior (absorbable vs. nonabsorbable) 3) Origin (synthetic, organic, vs. metallic) Increasing # of sutures is preferred compared to increasing suture size (weaken closure) Size ○ 12-0 smallest ex) renal transplant with cat ○ 4-0 / 3-0 = SQ SA suturing ○ 2-0 = SQ LA suturing ○ 2-3 = LA linea alba suturing ○ 7 largest “Leadrope” thick ○ Use the smallest DIAMETER suture that will adequately secure wounded tissue NO advantage to using stronger suture than the tissue Multifilament ○ Braided ex) polyester or coated caprolactam ○ Flexible ○ Easier handling ○ Less memory ○ Intermediate stiffness ○ Increased capillarity (do NOT use if area has possibility of infection) ○ Increased drag Increased likelihood of cutting tissue ○ ex) polyglycolic acid (dexon) and polyglactin 910 (vicryl) Monofilament ○ Noncapillary ○ Used for skin ○ Nylon Increased stiffness Non-absorable ○ Less drag ○ More memory ○ Decreased handling ability ○ More prone to weaken with forceps or needle drivers  ○ ex) polydiozanone (PDS II), polyglyconate (maxon), poliglecaprone 25 (monocryl), glycomer 631 (biosyn) Absorbable suture mechanisms (surgical/cat gut, chromic gut, and multifilament) ○ Used when you canNOT remove them ○ Organic sutures digested by tissue enzymes and phagocytized ex) Catgut but possible inflammatory rxn. Mainly used in cattle ○ Synthetic polymers broken down by hydrolysis Polyglycolic acid/dexon, polyglactin 910/vicryl, and poliglecaprone 25/monocryl RAPIDLY degraded in infected urine Nonabsorbable suture mechanisms ○ Encapsulated or walled off by fibrous CT ○ Use when CAN remove sutures (mainly skin) Normally 10-14 days = suture removal (take out every other suture at first for wounds under tension) ○ Silk = organic Decreased stiffness examples if Slightly weaker AVOID with contaminated sites Great handling characteristics and common to use ○ Braided or monofilament = synthetic Strong Minimal tissue rxn I ○ Stainless steel = metallic Minimal tissue rxn Can CUT tissue, not commonly used Preferred method to place non-absorbable sutures? → inert as it reduces inflammation Knot = WEAKEST point in suture pattern → very important to be secure to avoid dehiscence 4 throws = secure ligature 5 throws = larger suture with LA  Capillarity: “absorbability” which is the process by which fluid and bacteria are carried into the interstices of multifilament fibers. → infection can persist as neutrophils and macrophages too large to enter fiber interstices Catgut absorbable suture: nonsynthetic/organic made of submucosa of sheep intestine or serosa of bovine intestine that elicits notable inflammatory rxn. → quickly degraded when exposed to digestive enzymes (MUST be within tissues and have contact with body fluids to absorb) Suture selection considerations? 1) Time 2) Infection risk 3) Wound healing 4) Dimension and suture strength Muscle suturing Not commonly recommended as it has poor holding power Sutures placed parallel to muscle fibers Tendon suturing Strong Nonabsorbable ○ Tendons = slow healing Minimal reaction Taper or taper-cut needle ○ Less traumatic to tissue Parenchymal organ suturing (liver, spleen, kidneys) Absorbable monofilament ○ ex) Monocryl Surgical yield: amount of angular deformation needle can withstand before being deformed Ductility: needle’s resistance to breaking under amount of bending Sharpness: angle of point and taper ratio of needle Common curved needles = ⅜ and ½ INSERT NEEDLE POINT CHART Delicate  Taper vs. reverse cutting vs. cutting needles? Taper: round needle that does NOT increase hole when passing through ○ Used for delicate tissue (ex- mesentery) so Reverse cutting: cutting edge on convex (outside) aspect and flat on inner aspect so skin will not tear when pulling suture through ○ More commonly used Conventional cutting: cutting edge concave aspect (inner), more prone to tears ○ Rare use Buhner needle: used in purse string prolapses F S needle: used to close cow skin, tough, NO need for needle holders Tissue healing? Internal organs, SQ, and skin = fast Fascia = slow ○ ex) linea alba = 8 wks Appositional: bringing edges of tissue together in order for site to properly heal (side to side). Subcutaneous vs. subcuticular sutures? Subcutaneous: simple continuous to provide more apposition so less tension applied on skin sutures. Ex) Fat Subcuticular: starts with burying knot and advanced in dermal tissue where bites are PARALLEL to long axis of incision and ends with buried knot. Absorbable with a cutting needle. Ex) Intradermal Horizontal Mattress pattern Strong tension relieving BUT can impede blood supply if Mainly used with stents (do not want to pull tissue too tight and cause necrosis) Eversion- movement outward Bites parallel to cut edge Vertical Mattress pattern Stronger than horizontal and less impingement of blood supply Eversion Bites perpendicular to cut edge I ffIt Near 34mm gaeai ers Installed Hontifest cruciate Gambee pattern Interrupted pattern used in intestinal surgery to reduce mucosal eversion (outward rotation of tissue) Simple Continuous pattern Series of simple interrupted sutures with knot at either end Perpendicular to incision where suture advanced above incision line at diagonal Maximum tissue apposition (perferred) dehiscence risk ex) closing linea alba and SQ tissue insulturematerial Ford interlocking = modification of this pattern ○ Left to right placement (opposite) Running pattern Suture advanced above and below incision line Fewer points of contact SC Running Less secure Inverting suture patterns: creates “seal” so won't leak for uterus, GIT, and urinary bladder where tissues does NOT come out to tissue edge Lembert pattern Vertical mattress variation where continuous placement Inverting pattern ○ CAREFUL NOT to “cuff” tissue deep to suture line in LA as possible obstruction i Ex) hollow viscera ** Difference btw Cushing and Connell patterns? ** Cushings: extends to submucosal layer, common with GIT or urinary bladder in LA, placed parallel from edge Connell: enters lumen delete cushings Parker-Kerr Oversew pattern Two-layer closure for inverted closure of transected, clamped, stump of hollow viscera Starts with cushing/connell Rarely used as causes lots of tissue inversion Heuristics: specific elements of skills (in surgery) 1) Cognitive with planning movements 2) Perceptual with recognizing tissues 3) Motor with handling tissues Surgical principles attributed to Dr. William Halsted? Meticulous techniques: handling tissue gently, aseptic technique, preserve tissue blood supply, eliminate dead space (can fill with blood creating seroma), control hemorrhage, and appose tissues with minimal tension Hemostasis Local anesthetics Patient care Iairflowoutlackcozexchan.ge Greatest dead space = SQ layer (can tack BW to SQ to minimize this in spay sx) Aberdeen knot compared to square knot @ end of continuous suture line? Use hands instead of instruments with one knot over the other Knot volume way LESS compared to square knot = less FB, increased healing, less o knot strength (increased holding capacity) bacteria, and increased Still only need 4 throws = secure ligature Good tissue handling with sutures Needle holders account for MOST wasted time if poor technique used MINIMAL closure of ratchet ○ Only for dense tissue (at least one “click”) Do NOT use thumb forceps on intestines Goal = mantaintain tissue apposition while avoiding ischemia Pencil grip = “Pressing” Fingertip grip = “Sliding” Pressing sliding Sharp vs. blunt dissection? Blunt- delicate organs or tissues when spreading out tissue ○ ex) femoral a. = use mosquito hemostat or finger Preserving blood supply Sharp- tougher tissue Dissection- separating tissue into smaller pieces Transection- removing tissue Electrocautery vs. electrosurgery? Electrocautery: coagulation of small tissue where electric current does NOT enter body and is generated into metal wire or probe Electrosurgery: coagulation of tissue where current ENTERS body, creating a circuit ○ Vessels < 1.5 - 2mm in diameter (larger = ligation or hemoclips) ○ “Cut” setting: constant wavelength with hemorrhage risk as no coagulation ○ “Coagulation” setting: intermittent wavelength that produces less heat Tissue dependent (can be used on muscle) ○ Monopolar vs. bipolar devices Monopolar: most common, active electrode through patient to ground plate. NEED large ground plate or else burn risk to patient. Direct- dry and clean field where lower amount of heat produced Indirect- touching electrode to instrument for more precise energy application and coagulation Bipolar: forceps-like handpiece is used where current passes through one tip of forceps to the opposite tip through tissue being held with forceps. Force transmits straight through tissue with NO ground plate needed. Used with precise coagulation to prevent damage to adjacent structures (ex- spinal surgery) Double ligation on large artery using circumferential and transfixation ligature Circumferential = used first, closest to the heart when following blood supply ○ Less likely to bleed ○ More likely to slip Transfixation= used next, ONLY square throws if used on blood vessels ○ Surgeons throw used on tissue ex) spay sx on ovarian pedicle ○ Used for larger arteries with SMALLEST suture size possible (improves knot security) ○ More likely to bleed b/c penetration into lumen of vessel ○ Less likely to slip Advantages using CO2 laser in surgery Most common in SA surgery Light energy absorbed by water into ST with little heat dissipating into surrounding tissues Less bleeding, pain, tissue swelling, and risk of infection ex) cat declawing procedures Laser pros and cons? Pros: decreased bleeding, swelling, and pain, kills bacteria as cuts Cons: specialized training, expensive equipment, and excessive thermal damage to surrounding tissues can occur ○ Negative effects of wound healing on primary closed incision Langer’s lines: relaxed skin tension lines where incisions should be made parallel to them → pinch skin and visualize which direction skin moves Tension IMPEDES healing Suture with increased # of sutures = preferred Limb immobilization ○ ex) splint so whenever animal takes step = less tension = less damage to wound area Tension relieving techniques ○ Walking sutures where skin is “pulled” over top of defect Evens out tension and decreases dead space ○ Vertical mattress, horizontal mattress, near-far-far-near suture patterns (best apposition and tension relief but MOST suture in wound) ○ Stents distribute tension evenly along suture to prevent pull-through ○ Close primary wound and create small wounds around in order for them to heal by second intention (speed healing of overall primary wound) ○ Buttons = pressure/tension distribution ATTACH SUTURE PICS Differences btw LA and SA suturing LA = larger suture, thicker skin, longer suture, frequent surgeon’s throws, RARE use of intradermal patterns, bites 15 mm apart SA = PDS II (monocryl) preferred for linea alba closure, intradermal patterns common, bites 5 mm apart ~ soaking sponge/cloth with saline before removing from hemorrhage = prevent clot disruption incisions agentstats precise #3 blade handle = #10, 11, 15 blades #4 blade handle = #20 or 22 blades 12 declawing Yarge hookonblade bladeused in 10blades mostngmmon  endothelium damage x̅ Haemophilia Inflammation proliferation remodeling Wah feet fjfifi i T.fi day thromoin.fi brinmeshwork grapation Eg i.II plasmin coreauownfio.in MAKE CHART/diagram of process Ofeedbackwantithrome Phases of wound healing? 1) Hemostasis = quick! ○ Balance vasoconstriction and vasodilation ○ Goal = stop bleeding while maintaining profusion 2) Inflammation = 4-6 days “debridement phase” with neutrophil (early) recruitment and then monocyte (later) transformation with pro-inflammatory functions helping in ALL phases of wound healing (macrophages). @ end = apoptosis of cells 3) Proliferation = 4-24 days with fibroplasia, angiogenesis, and epithelialization granulationtissue I 4) Remodeling = 21 days - 2 years where scar tissue forms ○ Highly variable ○ Some wounds take YEARS to heal ○ Matrix metalloproteinases- collagenases, gelatinases, and stromelysins Steps involved in hemostasis Endothelial cell disruption with vasoconstriction ○ Exposure vWF → coagulation cascade Endothelial cells release vasodilators → increase blood flow = redness and heat associated with inflammation ○ Mediated by? Histamines, NO, LTs, PGs, complement Into Post-capillary venule leakniness where protein leakage → edema! ○ Decreased osmotic pressure (concentration gradient across membrane) ○ Increased blood viscosity ○ Increased interstitial pressure (btw spaces within cells in tissues) Edema: results of protein leakage that facilitates delivery of soluble factors and cells → PAIN and loss of function, common in distal extremities (gravity) Vascular congestion: fluid loss due to edema with hemoconcentration (increase RBC concentration). Neutrophil diapedesis encouraged by what? Increased capillary permeability (leakiness) → first line of defense against contaminated wounds where they work to destroy debris and phagocytize bacteria → process ends when wound is completely cleaned up (end of early inflam.) Proud flesh: excessive granulation tissue from lack of apoptosis of cells, healing of wound is halted, excess bubbling could be present Size > dime = surgically removed to allow for healing to start again Steroids: decrease granulation tissue but also decrease epithelization and destroy bloods vessels initially aiding with healing ○ Inhibit phospholipases that initiate arachidonic acid cascade COX-1 and COX-2 inhibitors (anti-inflammatorys): inhibit cyclooxygenase → both moderate inflammation of Granulation tissue formation ~ day 5 Formed during the proliferation phase of wound healing by… ○ Macrophages debride and produce cytokines and GFs that stimulate BV formation (angiogenesis) and fibroplasia (formation granulation tissue) by DIRECTING fibroblasts ○ Fibroblasts proliferate and make ECM that produces type III collagen initially and then type I collagen later on before differentiating into myofibroblasts that contain actin to “squeeze” wound down woundcontraction ○ Blood vessels carry oxygen and nutrients needed for cell metabolism and growth Great temporary barrier of infection that prevents any bacteria from entering wound No nerve endings present ○ Can cut into it Wounds gradually increase strength during this stage → 7-14 days matching suture removal time Increase tissue hypoxia = increase vessel ingrowth (only method to bring nutrients to area) or Epitheliazation Often forms around layer of granulation tissue (centripedal) Protection layer Skin cells can NOT migrate over tissue Do NOT use Neosporin once at this stage as neosporin will destroy these cells ○ Completely unnecessary as granulation tissue already protecting wound Healing stops when…? Wound edges MEET! Things on  to Shock → SIRS → MOD SIRS: Systemic inflammatory response syndrome COULD be normal response but normally seen as an overreaction to a variety of different causes ○ ex) burns, heatstroke, neoplasia, pancreatitis, trauma “Cytokine storm”, leukocyte dysfunction, or delayed resolution to inflammation DIC possible towards the end MUST meet with 2 of the causes 1) Hyper or hypothermia 2) Tachycardia 3) Tachypnea 4) Leukopenia initially followed by leukocytosis (>48hrs) when WBCs released from sequestered areas Primarily neutrophil change 5) Depression Hyperthermia = IL-1, IL-6, TNF-alpha, and PGE2 (pro-inflammatory cytokines) acting on hypothalamus to produce fever Hypothermia = shock with vasoconstriction where blood canNOT go into tissues → cyanotic extremities (cold ears, limbs) → very BAD Process of tachycardia? Direct increase of HR due to pain Vasodilation → hypotension (from fluid shift with dehydration) → decrease cardiac output → increasing HR (compensate) Process of tachypnea? Pain directly causing rapid, shallow breathing Vasodilation with clotting dysfunction → hypoperfusion → lactic acidosis → metabolic acidosis Stress response associated with IL-1 and TNFalpha → increased corticosteroids → REDUCE healing as they decrease inflammtion and growth factors Stress leuk: neutrophilia, monocytosis (dogs), lymphopena, eosinopenia MODS: Multiple organ dysfunction syndrome where combination of shock, endothelial cell dysfunction, inflammation, etc cause fatal organ dysfunction L → homeostasis cannot be maintained without intervention  horaco abdominal 1m LDS ligatingdividing doublerowstaples mesentericvessels ffÉtFfidÉ chain Ecraseur Serra Emasculator crush Emasculator eastestaneously 8919 casestudiese vomiting intraabdominal pressure thansuturestrength footcasts P Later ffm EYnTealing Bellywrap useto coverhernia toreduce size preventstrangulation Blocks Highpoint Child.totostaiedosmhgualdwhgtbe as it loosenswhen wet Lowpoint a geinnta.EE gneea astern ssufciticatPa soebook them abaxial Beta Parmardigitain ciciaeinieiiiiiiden.si eseaisk ff.figiIndo sagly.aem when notgoingthrottling  Absorbable (common name) Generic name Non-absorbable (common name) Generic name Vicryl Polyglactin 910 multi, medium term Nylon Polyamide mono or multi, stiff Monocryl Poliglecarpone 25 mono, medium term Novafil Polybutester mono PDS II Polydiaxanone closing SA linea alba, long term Prolene Polypropylene mono, vas. anastomoses Maxon Polyglyconate mono, long term Ethibond Coated Polyester multi Catgut Surgical Gut notable inflammatory response Perma-hand Silk multi, less stiff, good handling Dexon Polyglycolic acid multi Stainless steel Surgical Steel metallic, rare use, cut tissue degraded in urine inert placement monofilament memory handling noncapillarity multifilament memory handling capillarity.TW