Lower GIT Surgery Flashcards
Describe the intestinal tract anatomy
- Duodenum; fixed proximal part, starts at the pylorus
- common bile & pancreatic ducts
- Jejunum; starts at duodenojejunal flexure
- Ileum; short terminal portion
- antimesenteric vascular supply
Blood supply of Intestines?
Cranial mesenteric artery
Layers of Intestinal tract?
Mucosa, submucosa, muscularis, serosa
How long is the critical period for intestinal healing ?
3-5 days
What are the three phases of intestinal healing?
» * Lag phase: day 1-3/4
» fibrin clot, minimise leakage
» By day 3, epithelial migration seals the wound
» * Proliferative phase: day 3/4- 14
» Proliferation of fibroblasts, collagen produced
» rapid gain in strength (near normal in 14=17 days)
» * Maturation phase: day 14-180,
» reorganisation and maturation of collagen
When does wound breakdown potentially happen?
In lag phase; most dehisence at 3-5 days
hat material should we use on intestinal closure?
» Suture material: monofilament synthetic absorbable (PDS)
* (surgical staplers)
* round bodied or tapercut needle
* Swaged
* 3-0, 4-0
What suture pattern to use on intestinal closure?
» Suture pattern: Appositional, single-layer
» simple interrupted or continuous, modified gambee
» well apposed with moderate tension
» ensure submucosa engaged
» 2mm from edge, 2-3 mm apart
How can we reinforce suture lines?
Omental patch ‘abdo police’, serosal patch ‘surgical parachute)
Describe Omentalisation
; routine in abdominal surgery
➢ wrap sites in omentum +/- tacking sutures
➢ important in colorectal & oesophageal surgery
* placed on surface of organs where viability doubtful or cannot resect
Describe serosal patching
» If viability doubtful, or when healing is impaired
* hypoproteinaemia, peritonitis, or chemotherapy
➢ remote intestinal loop sutured adjacent to the wound
» Rarely needed
Describe steps to enterotomy
- Exteriorise and pack off affected bowel
- Occlude either side of incision with fingers/atraumatic clamps
- Sharp longitudinal incision on antimesenteric border
- Close; simple interrupted or continuous appositional pattern
➢ suture 2-3 mm from edge, 2-3 mm apart, submucosa engaged
➢ longitudinally or transversely - Leak test
- Omentalise
- Abdominal lavage & suction
- Count swabs
- Change gloves & kit
10.Close abdomen routinely
What should we do after closing intestines?
LEAK TEST it with enough fluid to get firm pressure
What are soem different intestinal biopsy techniques?
- Endoscopic biopsy: least invasive
» Direct visualisation
» Limited; mucosa & submucosa and areas within reach of endoscope - Wedge resection: small enterotomy
» full thickness - Punch biopsy: dermal punch
» full thickness
Describe how you would do an enterectomy & end to end anastomosis
- Exteriorise segment of intestines, pack off with swabs
- Milk luminal contents away from resection site
- Place clamps (traumatic or atraumatic) either side of area to be resected
- Occlude oral and aboral to clamps with fingers/atraumatic clamps in healthy tissue
- Make window in mesentery
- Identify blood supply to affected segment & double ligate vessels
- Sharply excise between clamps
- Perform anastomosis with sutures or staples
➢ place sutures at mesenteric & anti mesenteric borders first - Leak test & place additional sutures as needed
10.Close mesenteric rents
11.Omentalise
What should we be aware of? !
Preservation of blood supply
How do we anastamose with luminal disparity?
Describe Dehisence (from peritonitis) as post op cpmplication
- 16% of patients after small intestinal surgery
- 3-5 days post operatively
- Acute vomiting, depression, anorexia, abdominal pain, hypovolaemic&endotoxic shock
How can we diagnose post op peritonitis?
- Serology; ↑ band neutrophil
- Rads; difficult to interpret (+contrast difficult with ileus)
- Ultrasound; useful for abdominocentesis
- Definitive diagnosis; cytology
- consider repeating cytology at intervals to look for changes
What should we do if signs of acute abdo crisis post op?
SURGERY
➢ Extra sutures, or resection and anastomosis
➢ Copious lavage
➢ Omental or serosal patching is mandatory
➢ +/- peritoneal drains or open peritoneal drainage
What are some risk factors to dehisence & peritonitis?
pre-operative peritonitis,
low albumin, intestinal trauma,
intestinal foreign bodies and multiple
intestinal procedures.
Mortality: 50-80%
What may be a good indicator of septic peritonitis in dogs?
Glucose
Describe ileus as post op comp?
- secondary to abdo surgery, peritonitis, electrolyte disorders and some drugs
- sympathetic nervous system ↓ myoelectrical activity for ~ 24 hours post-op
Why can we see ileus?
Poor surgical technique: poor tissue handling, desiccation of tissues, excess retraction and
prolonged surgical time
CLS of Ileus?
vomiting/regurgitation and abdominal distension
* usually within 24 hours
Tx for ileus?
Tx underlying cause
➢ Prokinetics - Metoclopramide
➢ symptomatically or prophylactically
➢ stimulates duodenal & jejunal peristalsis, increases gastric contractility, decreases pyloric tone, and
decreases gastric emptying and intestinal transit
Describe short bowel syndrome
» Rarely reported in small animals,
» If >70% of small intestine resected, ileocaecocolic valve resection
» Clinical signs: watery diarrhoea and weight loss
Short and long term tx for short bowel syndrome?
» Short-term medical treatment: intravenous fluids +/- total parenteral nutrition
» Long-term management: enteral nutrition that is easily digestible, high in fibre fed in small meals 6-8
times daily
» +/-Anti-diarrhoeal drugs
» +/-Antibiotics for bacterial overgrowth
What nutrition considerations with post op intestine sx?
» Evidence that withholding food is more detrimental to intestinal healing than early feeding
» Enterocytes receive nutrients directly from enteral feedings
» Primary energy source is glutamine
» Hypoalbuminemia → Increases risk of dehiscence
how should we feed them then?
» Current best practice → provide small, highly digestible food as soon as the animal is able to eat
(certainly within 12 hours)
» Consider pre placing feeding tubes (nasogastric, oesophageal) at surgery
» significant weight loss or anticipated to not eat after surgery
what is the most common indication for intestinal sx?
FB -> partial or complete obstruction
What can happen with FB?
- Obstructs due to Narrowing at pylorus, distal duodenum, proximal jejunum
- Mucosal trauma as travels through intestinal tract
most common obstruction site?
in jejunum but occurred at all areas of GIT
what increases mortality with intestinal sx?
Longer duration of signs, linear foreign body and multiple intestinal procedures significantly increase
mortality.
* Degree of obstruction and location do not affect survival.
Dx of intestinal FB?
Radiography
* Radio-opaque FBs
* Non radio-opaque
* Dilated loops of bowel proximal to complete obstruction;
* normal small intestinal diameter = 1.6 times the height L5
* >80% chance of obstruction if diameter is >1.95 times the height of L5
* Partial obstruction may require ultrasound or contrast study
Tx for FB?
Stabilisation, then enterotomy
➢ Incise aboral to the level of obstruction
➢ Milk foreign body down to incision
➢ enterectomy if bowel not viable
PG?
usually quite favorable
Describe linear FBs?
- Rarely cause complete obstruction
- Fixed proximally, under tongue (cats) or pylorus (dogs);
- intestines ‘walk up’ the linear material with peristalsis
- Erodes mesenteric border → perforation and peritonitis
Dx of intestinal FB?
Radiographic and ultrasonographic findings include intestinal PLICATION and tapered gas bubbles
Tx for linear FB?
- Gastrotomy and multiple enterotomies
- Single enterotomy catheter technique
- Enterectomy if large areas of perforation
Pg for linear fb?
» Prognosis; good for cats with no perforations
» Prognosis; guarded for dogs (>30% have perforation and >40% require resection)
Describe intussuception
- Invagination(‘telescoping’) of one intestinal segment (intussusceptum) into lumen of another
(intussuscipiens) - young → gastrointestinal disease or parasitism
- older→ mass lesions
CLs of intussuception?
» Clinical signs: obstruction; vomiting, diarrhoea, depression, anorexia.
* can protrude from anus
* differentiate from rectal prolapse by passing probe between prolapse and rectum
Dx of intussuception?
palpation of a ‘sausage’ shaped abdominal mass, radiographs Ultrasonography →‘target’
pattern
Tx for intussuception?
Gentle traction to reduce if possible
* If nonviable, then enterectomy
* +/- enteroplication (not routinely recommended)
Describe mesenteric volvulus
- Twisting of intestines around root of the mesentery
- Uncommon
- vascular compromise, tissue ischemia, and luminal obstruction
Who do we see mesenteric volvulus in ?
- Signalment: Male, medium-to-large, sporting or working breeds; German shepherds & English pointers
- Young adult dogs (2 to 4 years of age)
CLs of mesenteric volvulus?
- Clinical signs: peracute to acute; pain, shock & abdo enlargement
- nausea, retching, vomiting, hematochezia, depression, weakness, recumbency
DX of mesenteric volvulus?
Radiographs, elnarged loops of bowel
Surgical technique for volvulus?
- confirm diagnosis and determine direction of twisting
- intestine will be dilated, oedematous, discolored, red → black
- Evaluate intestinal viability and resect devitalized tissue (up to 80%)
- lavage copiously
- +/-open peritoneal drain
What locations of intestinal neoplasia?
- Cats; distal jejunum, ileum most common
- Dogs; large intestine
What are the most commonly seen intestinal neoplasms?
➢ adenocarcinoma, lymphoma, leiomyosarcoma and leiomyoma
Presentation of small intestinal neoplasia?
- mean age at presentation is 9-10 yrs
- usually advanced at the time of diagnosis; high metastatic rates
- Clinical signs; obstructive disease and include weight loss, vomiting, diarrhoea
What specific forms of neoplasms can we see in SI?
- Adenocarcinomas; 3 forms=ulcerative, annular or proliferative
- Lymphoma; discrete or focal (FeLV)
Tx for SI neoplasia?
tment:
* Apart from lymphoma, surgical resection with wide margins (4-8 cm)
* Biopsy local lymph nodes
* Lymphoma →chemotherapy
mean survival?
l for adenocarcinoma, leiomyosarcoma ~10 months
Describe LI dehisence & leakage
can happen anywhere below:
* caecum, colon (ascending, transverse, descending), rectum and anus
* 4 layers: mucosa, submucosa, muscularis, and serosa.
* colon is attached to body by mesocolon –less mobile than SI-position less variable
BS of LI?
segmental directly from vasa recti (cranial and caudal mesenteric artery)
* rectum by cranial rectal artery
CLS of LI issue?
tenesmus, dyschezia, haematochezia, mucus, constipation/obstipation or diarrhoea
Dx for LI
; Radiography, Barium enemas, Ultrasound & Endoscopy, rectal exam
when should enemas not be done?
before sx -> low residue diet or 48-hour period of starvation
What is not a good reason for Colonic sx?
FB! `DONT DO IT
(* Biopsies (full thickness) are not taken routinely at open surgery
* Colonic foreign bodies can be milked out of the rectum)
Indications for colonic sx?
➢ subtotal colectomy (feline megacolon)
➢ colonic mass
➢ intussusception
Describe megacolon?
» Irreversible dilatation of the colon, hypomotility, chronic constipation
Causes of acquired megacolon?
- extraluminal compression: pelvic fractures, prostamegally, pelvic masses and stictures
- intraluminal compression: foreign bodies, neoplasia, strictures
- metabolic: hypokalaemia, hypothyroidism
- neuromuscular abnormalities: sacral spinal cord deformities (Manx cats), ileus, dysautonomia
Feline megacolon?
Mostly idiopathic, middle aged cats
Signs & dx of feline mgacolon?
» Signs: constipation, obstipation, tenesmus, anorexia, vomiting, dehydration, weight loss, pain
» Rads: confirm impaction. Colon diameter >1.5 times the length of L7 on lateral rads
Medical management of megacolon?
rarely successfully
- correction of fluid and electrolyte abnormalities (hypokalaemia)
- manual removal of faecoliths
- IV antibiotics
- stool softeners
- laxatives
- high fibre diets
- prokinetic drugs: cisapride
Sx management of megacolon?
Subtotal colectomy
Who handles colectomy well ?
CATS (dogs do not)
Describe subtotal colectomy
- Removal of 90-95% of the colon
- Megacolon, neoplasms, irreducible intussusception and trauma
- Preserve iliocaecal valve if possible
Describe preservation of iliocaecal valve?
➢ shortens postoperative recovery
➢ decreases diarrhoea due to small intestinal bacterial overgrowth
➢ more difficult to achieve tension free closure if valve preserved
Outcome of colectomy?
Diarrhoea for ~ 8 weeks
* ileocaecal valve removed, diarrhoea can persist for 3 months
indications for typhlectomy?
caecal inversion, perforation, tumour
(leiomyosacoma)
Describe typhylectomy?
- ileocaecal fold is transected
- two clamps are placed at the base of the caecum
- transected between the clamps & suture base
- appositional sutures or over the clamp Parker-Kerr
suture
what should we preserve in typhlectomy ?
- Iliocolic junction should be preserved if possible →
diarrhoea - may not be possible with some tumours
Describe LI neoplasia cats vs dog?
» Dogs more commonly
* Adenomas, adenocarcinoma, lymphosarcoma, leiomyomas, leiomyosarcoma, carcinoids
» Cats
* adenocarcinoma, lymphoma, mast cell tumours
CLS of LI neop?
: tenesmus, dyschezia, haematochezia, weight loss, diarrhoea, vomiting
➢ May be evident on abdo/rectal palpation
Sx for LI neop?
➢ margins of 4-6cm recommended
➢ pelvic osteotomy may be required
