Approach to the Small Animal Abdomen 2025 PDF

APPROACH TO THE SMALL ANIMAL A B D O M E N 2025 ALISON LIVESEY MRCVS LEARNING OBJECTIVES By the end of this lecture you should be able to: 1. Understand the indications for surgical abdominal exploration in companion animals 2. Describe how to perform safe, e...

APPROACH TO THE SMALL ANIMAL A B D O M E N 2025 ALISON LIVESEY MRCVS LEARNING OBJECTIVES By the end of this lecture you should be able to: 1. Understand the indications for surgical abdominal exploration in companion animals 2. Describe how to perform safe, effective and systematic exploration of the abdomen in small animals 3. Describe the standard surgical approach to the abdomen in small animals 4. Describe the standard 3 layer closure of a ventral midline abdominal wound in small animals 5. Recognise the significance of more specialised procedures such as laparoscopy #uniofsurrey 2  ABDOMINAL EXPLORATORY PROCEDURES Routinely performed in first opinion practice Useful diagnostic & therapeutic tool Standard approach Neutering, FB retrieval, urinary calculi removal, biopsy... Healthy stable patients AND critically unwell patients » TIP: learn ‘normal’ – routine spays #universityofsurrey 3 INDICATIONS Diagnostic/prognostic Therapeutic Preventative Sampling to Haemoabdomen Neutering * get/confirm diagnosis Peritonitis Gastropexy Culture Mass removal (plication) Histopathology Obstruction/Torsion Colopexy Cytology Trauma/Hernia Visual inspection Calculi Congenital (shunt/ectopic ureter) Enteral/cystostomy tube placement Dystocia/Pyometra Sub total colectomy #universityofsurrey 4 INTESTINAL PLICATION Previously performed to prevent recurrence intussusception No longer advised EXPLORATORY LAPAROTOMY - OPEN CELIOTOMY Advantages Disadvantages Direct visual and Invasive tactile inspection Costs? Good sample Risk collection GA, pain/morbidity Potential to perform Time consuming? therapeutic procedure #universityofsurrey 6 DO I NEED TO REFER THIS PATIENT? ▪ Haemoabdomen-splenic bleed versus hepatic bleed? ▪ Perforated foreign body? ▪ Do I have the equipment to perform this procedure? ▪ Do I have the aftercare for this patient? ▪ Am I sure this is an abdominal problem vs. spinal problem WHEN TO EX LAP? AVOID UNNECESSARY SURGERY Utilise other tools to get diagnosis Thorough history and physical exam Radiography +/- contrast Get help with interpretation Serial rads-care with Barium Risks with aspiration pneumonia/abdominal spills Ultrasound Endoscopy Minimally invasive biopsy techniques CT/MRI Localise to abdomen-care with spinal pain Too unstable to survive GA/procedure Total costs (diagnostics and ex lap vs straight to ex lap) #universityofsurrey 8 SUCCESSIVE RADIOGRAPHS SI Diameter >1.9 compared to L 5 vertebral body height likely to be obstructed IMAGING This dog had no Foreign Body Imaging This picture taken 24 hours after barium-FB in stomach Contrast radiography largely superseded by ultrasound Intussusception best diagnosed by ultrasound  POINT OF CARE ULTRASOUND-LOOK FOR FLUID 1) Diaphragmatic-hepatic view (DH) 2) Cystocolic (CC) 3) Splenorenal (SR) 4) Hepatorenal (HR) Free fluid always abnormal Does not always indicate septic peritonitis PREPARE THE OWNER – GOOD COMMUNICATION » Emotive, costly, outcomes unknown, last resort »Good communication and informed consent How you decided Ex lap best option? May be the best option if FB not visible on xray Risks of potential procedure? Potential outcomes during the procedure and after? Diagnostic, prognostic or therapeutic options likely to be? Potential for euthanasia under GA? #universityofsurrey 1 PRE-OPERATIVE STABILISATION » ↓ morbidity/mortality Chronic Acute/Emergency Co-morbidities Intravenous fluid Clotting Hypovolaemic CVS Dehydrated Correct electrolytes Correct electrolytes Correct dehydration Parenteral nutrition #universityofsurrey 1 WHAT WILL YOU FIND? BE PREPARED What do you need? Intestinal mass Biopsy Abdominal retractors Enterectomy/anastomosis Suction/lavage Foreign body obstruction Multiple haemostats – curved, long Enterotomy/enterectomy handled Intussusception Extra swabs Splenic mass Assistant? Liver mass Blood transfusion? Disseminated neoplasia Place a feeding tube prior to closure #universityofsurrey 1 ADEQUATE EXPOSURE HALSTED’S PRINCIPLES 1. Gentle tissue handling 2. Meticulous haemostasis 3. Preservation of blood supply 4. Strict aseptic technique 5. Tension free closure 6. Accurate apposition of tissues 7. Eliminate dead space #universityofsurrey 11 PREPARE THE PATIENT Dorsal recumbency WIDE CLIP & PREP – be prepared 4 corner draping Retract prepuce/catheterise Large surgical incision Xiphoid to pubis Extend incision parapreputial in male dog s Sever preputial muscle Ligate branches of epigastric vessels Fossum, Small Animal Surgery #universityofsurrey 12 EX LAP MALE PATIENT Tobias, K. M. (2017). Manual of small animal soft tissue surgery Wiley Blackwell.  Spay prep BSAVA Manual of Canine and Feline Abdominal Surgery #universityofsurrey 13  BSAVA Manual of Canine and Feline Abdominal Surgery #universityofsurrey 14 SURGICAL APPROACH; MIDLINE ABDOMINAL INCISION * Swab count! (instrument count) Ventral midline skin incision Sharp -Slide Cut - one long smooth incision (avoid stop & go incising) Fingertip Grip Sharply dissect subcutaneous tissues Do not excessively undermine Expose linea alba BSAVA Manual of Canine and Feline Abdominal Surgery #universityofsurrey 15  COMMON ERRORS IN SKIN INCISIONS Stop and go’ cutting – serrated edges – healing problems Not incising long enough Not full thickness in one go use distance of skin separation as a guide – roughly 1.5 cm gap Not stabilising skin around the incision Incising too deep in first cut leads to bleeding or worse Going ‘off – line’ Incise with scalpel perpendicular to the floor (hold perpendicular to skin surface) overriding edges at closure due to angle of cut #universityofsurrey 16  SURGICAL APPROACH Tent linea alba with forceps Stab incision with scalpel Reverse blade Beware bladder, engorged stomach/intestines/uterus, spleen, mass Check for adhesions #universityofsurrey Clinician’s brief 17 SURGICAL APPROACH Carefully extend incision along linea with scissors or blade Tent with fingers/forceps Reverse/backhand cut with scissors Avoid rectus abdominis muscle Long incision Better exposure Less painful BSAVA Manual of Canine and Feline Abdominal Surgery #universityofsurrey 18 SURGICAL APPROACH Remove falciform fat Abdominal retractors Moistened laparotomy swabs http://www.vetsurgeryonline.com/ #universityofsurrey 19  Ligated falciform fat xyphoid diaphragm pubis #universityofsurrey 20 ABDOMINAL EXPLORATION FULL SYSTEMATIC APPROACH Cranial → caudal vs quadrants Texture/appearance/location Abdominal fluid Gut motility Presence and appearance/size of Lymph tissues Gentle tissue handling – gloved fingers, moistened swabs, stay sutures Avoid tissue desiccation – moistened swabs/saline flush NOTE: If trauma/haemorrhage/leakage of GIT contents or dystocia – identify and treat first » TIP: ask someone to take notes/photos so you don’t forget later #universityofsurrey 21 IDENTIFY, PALPATE AND VISUALLY INSPECT ALL ORGANS » Cranial quadrant Liver – all lobes Gallbladder (between right medial and quadrate lobes) Can express gall bladder to make a judgement on duct patency Diaphragm Spleen and stomach Duodenum and pancreas (right and left limb) Kidneys and adrenals Ovaries and uterus » Caudal quadrant Jejunum, ileum and colon Lymph nodes Urinary bladder https://todaysveterinarypractice.com/radiology- imaging/imaging-essentials-small-animal-abdominal- ultrasonography-liver-gallbladder-part-1/ Prostate #universityofsurrey 22 IDENTIFY, PALPATE AND VISUALLY INSPECT ALL ORGANS »Right quadrant Duodenal manoeuvre right kidney adrenal gland ovary ureter »Left quadrant Colon manoeuvre left paravertebral fossa #universityofsurrey Clinician’s brief 23 IDENTIFY, PALPATE AND VISUALLY INSPECT ALL ORGANS »GIT Exteriorise and ‘run through’ Examine omentum and mesentry »Keep organs moist with swabs and flush https://vetgirlontherun.com/run-the-bowel-abdominal- expore-vetgirl-veterinary-ce-video-blog #universityofsurrey 24 DUODENO-COLIC LIGAMENT Often can inspect the colic lymph nodes here Common site of obstruction Need to break down the ligament to resect this piece of intestine  I didn’t find anything! What do I do? What will I tell the owners? There is no such thing as a negative ex lap SAMPLE Biopsy areas of interest – risk vs benefit Lymph nodes/lymph tissue/GALT Explain risks of potential procedures prior to sx Fluid for cytology/Air dried smears/impression smears Gallbladder Urine Abdominal fluid Histopathology and cytology Bacterial culture and sensitivity Tissues Fluids #universityofsurrey Images from http://www.vetsurgeryonline.com/27 BIOPSY Isolate area of interest Pack off with moistened laparotomy swabs Gentle tissue handling Stay sutures Atraumatic forceps Assistant’s fingers Take sufficient samples – size and number Close appropriately for organ Fossum, Small Animal Surgery Use appropriate suture material monofilament, absorbable, small needle, round bodied Prepare samples appropriately – EDTA, formalin, slide LABEL SAMPLES Change kit and gloves prior to closure if entered hollow viscous/neoplasia #universityofsurrey 28 WOUND CLOSURE Count your swabs! Check biopsy sites Count your swabs! Copious lavage WARM, sterile saline Completely remove via suction Change instruments and gloves If entered a contaminated viscous GIT, bladder etc FB, biopsy Count your swabs! Peritoneal/incisional block BSAVA Manual of Canine and Feline Abdominal Surgery #universityofsurrey 29 WOUND Count your swabs! CLOSURE #universityofsurrey 30 Retained swab  WOUND CLOSURE – 3 LAYER CLOSURE * 1. Linea alba Incorporate rectus abdominis muscle sheath Wide bites 0.5-1 cm 0.5-1 cm apart Avoid subcut tissues Simple continuous or interrupted Synthetic absorbable #universityofsurrey 31 #universityofsurrey 32 NUMBER OF THROWS Suture material Interrupted Continuous Start knot Continuous end knot Polyglactin 910 (vicryl) 3 3 6 Polydiaxanone (PDS) 4 5 7 Polypropylene (prolene) 3 3 5 Nylon 5 5 6 Poliglecaprone 25 (Monocryl) 4 4 6 » For interrupted Minimum of 3 throw for multifilament Minimum of 4 throws for monofilament » Continuous One throw added to start Two throws added to end #universityofsurrey 33 #universityofsurrey 34 #universityofsurrey 35 WOUND CLOSURE – 3 LAYER CLOSURE * 2. Subcutaneous layer Obliterate dead space and appose skin edges Simple continuous Synthetic absorbable Male dog suture preputial muscle High risk seroma male dog 3. Skin closure Do not overtighten Intradermal, simple interrupted, ford interlocking, staples #universityofsurrey 36 First layer – closed rectus sheath/linea alba Second layer – closed subcut #universityofsurrey Third layer – intradermal skin closure 37  Top Tips – 3 layer closure » Suture appropriate size for patient » 3-0 (2 metric) for small cat; 2-0 (3 metric) small dog; 0 (3.5 metric) medium to large dog;1 (4 metric) giant breed dog » Simple continuous does not increase risk of dehiscence if performed correctly » 6-8 throws at each end of continuous pattern (+1 for end of row) » Bites 5-10 mm of the external fascial sheath » Pass needle slightly obliquely, to avoid eversion of the linea » In male dogs, two layers to close the subcutaneous fat and preputial muscle » Avoid dead space » Do not overtighten skin sutures » Obliterate dead space with subcut closure #universityofsurrey 38 POST-OPERATIVE PATIENT CARE Analgesia Antibiosis if indicated Turning if non ambulatory Care of catheters, drains, feeding tubes Continued monitoring of hydration and fluid replacement/maintenance Serial monitoring and exam Dependent upon procedures performed #universityofsurrey 39 COMPLICATION OF LAPAROTOMY WOUND Seroma formation Wound breakdown/dehiscence→herniation Avoid with good technique and proper post operative rest Infection Suture reaction Adhesions Iatrogenic peritoneal fb COUNT YOUR SWABS Can lead to abscess formation years after #universityofsurrey 40 COMPLICATIONS OF LAPAROTOMY Peritonitis – inflammation of peritoneum Caused by abdominal sx (rupture/necrosis of organ, FB penetration, GDV) Mortality 50-70% Clinical signs anorexia/depression, V+/D+, fluid dripping form surgical incison, abdo pain, progresses to shock Diagnostics bloods – generalised dehydration and infection HCT and TP, hypoproteinaemic, hypoglycaemic Abdominocentesis and cytology Treatment antibiotics, supportive care, peritoneal lavage #universityofsurrey 41 COMMON MISTAKES not large enough clip not large enough incision not exploring all areas not taking enough or appropriate biopsies not being prepared for likely findings – know when to refer if you need to choosing the wrong cases? #universityofsurrey 42 #universityofsurrey 43 LAPAROSCOPY Advantages Disadvantages Minimally invasive Limited tactile Good visual inspection inspection Unable to perform Good biopsy samples some procedures from most organs Specialists equipment Potential to perform and training some therapeutic Costs procedures Time consuming? #universityofsurrey 44 LAPAROSCOPY Common uses in companion animals Ovariectomy (ovariohysterectomy) Biopsy Liver Cholecystectomy Lap- assisted gastropexy Lap- assisted cyrptorchid castration Lap- assisted cystotomy? Detection of small lesions/assessment of disease (Can ‘have a look’) #universityofsurrey 45 LAPAROSCOPY » Wide clip and prep » Abdomen inflated with CO2 using veress needle (blind) Trochar » Trocar/cannula inserted for scope (blind) » Further instrument port inserted (under direct visualisation) » Surgical procedures performed by placing instruments into the port and working inside the inflated abdomen » Tissue can be removed from abdomen via ports » Lap assisted techniques Locate tissue of interest inside abdomen Withdraw tissue out of abdomen via a further incision for procedure Veress needle #universityofsurrey 46 TOP TIPS – EX LAP Good work up before proceeding Be prepared to deal with what you find Have a plan A, B, C Be thorough, systematic approach Don’t get side tracked! Take appropriate samples and package them correctly Gentle tissue handling – stay sutures, assistant Be logical and use your knowledge Good client communication essential #universityofsurrey 48  https://todaysveterinarypractice.co m/soft-tissue-surgery/a-guide-to- exploratory-laparotomy/ https://www.veterinary- practice.com/article/step-by- step-approach-to-the-abdominal- cavity-in-small-animals-part-1 Video: Exploratory Laparotomy – Veterinary Surgery Online #universityofsurrey 49