Stomach Surgery Flashcards
What are the most common gastric foreign body etiologies? Examples in dogs and cats?
things ingested by patient or penetrating wounds
- DOGS = rocks, toys, anything
- CATS = trichobezoars, needle, string*
What is the most common signalment associated with gastric foreign bodies?
- younger animals (but can be any age)
- previous history of FB ingestion
- pica
What are some conditions that predispose to pica?
- behavioral
- pancreatic exocrine insufficiency
- hepatic encephalopathy
- iron deficiency
What are the most common history and physical exam findings associated with gastric foreign bodies?
HX: observation or history of consumption, vomiting, anorexia, may be asymptomatic
PE: often unremarkable, distended abdomen, dehydrated, hematemesis, melena
What are 6 common findings associated with chronic gastric foreign bodies?
- hemoconcentration (dehydration) or anemia
- pre-renal azotemia
- acidosis: dehydration
- alkalosis: vomiting
- hypokalemia and/or hypochloremia secondary to vomiting
- leukocytosis
How should patients be stabilized before treatment of gastric foreign bodies?
- fluids
- electrolytes
- analgesics
- gastroprotectants
When is emesis contraindicated with gastric foreign bodies? What 2 specific therapies are used?
if FB is obstructive
- LEAD - chelation
- ZINC - transfusion
Where is it preferred to make incisions in the stomach?
- hypovascular area on the ventral aspect
- avoid esophagus and pylorus
(make incisions big enough so the stomach is not traumatized with foreign body removal)
How does the stomach heal? What is the holding layer?
rapidly!
submucosa —> proper apposition results in stronger closure
What enhances formation of the fibrin seal in the stomach?
serosa-to-serosa contact
- water-tight closure is mandatory
What 2 things complicate suturing gastrotomies?
- reduced gastric volume
- reduced tissue pliability
What is the traditional way of closing gastrotomies?
2 layer closure
- Cushing or simple continuous pattern through serosa, muscularis, and submucosa
- oversewn with Lembert or Cushing pattern through serosal and muscularis layers —> further inverts to get a seal
What are some alternate techniques for closing gastrotomies?
- simple continuous in submucosa
- Cushing pattern in seromuscular layers = tighter closure due to better submucosal apposition
- simple continuous in serosa, musclaris, and submucosa
- Cushing pattern in seromuscular layers = more eversion leads to more gastric volume loss
What are the preferred layers of gastrotomy closure?
- simple continuous in just the submucosa or including the serosa, muscularis, and submucosa
- Cushing pattern with a buried suture inverts and provides serosal contact
When is a single layer closure to gastrotomies preferred? Which patterns are used?
reduced gastric volume caused by pyloric outflow tracts or thickened gastric wall
- simple continuous
- simple interrupted
What is congenital pyloric stenosis (gastric outflow obstruction)? In what breeds is it most common?
hypertrophy of circular muscles of the pylorus, causing obstruction of gastric contents
- brachiocephalic breeds < 1 year of age
- rare in Siamese cats
What is thought to be the etiology of pyloric stenosis (gastric outflow obstruction)? What are the most common signs?
excess gastrin
starts at weaning, when puppies/kittens are switching to solid foods
- intermittent vomiting
- normal to decreased body condition
- abdominal distension without pain
How is pyloric stenosis (gastric outflow obstruction) diagnosed?
- RADIOGRAPHS: gastric distention with delayed gastric emptying and “beak” or apple core near the narrow outflow
- ENDOSCOPY: cannot observe the muscle, but will likely see retained ingesta
- ULTRASOUND: layer thickness
What are the 2 treatment options for pyloric stenosis?
- Fredet-Ramstedt pyloromyotomy
- Heineke-Mikulicz pyloroplasty
How is a Fredet-Ramstedt pyloromyotomy performed?
- isolate pylorus
- longitudinal incision through seromuscular layer up to the submucosa to cause a submucosa bulge
- leave incision open
seromuscular layers
What are 2 advantages and disadvantages to Fredet-Ramstedt pyloromyotomies?
ADVANTAGES: quick and easy, less chance for contamination
DISADVANTAGES: no lumen exposure for inspection or biopsy, stenosis may recur (possibly only temporary benefit)
How are Heineke-Mikulicz pyloroplasties performed?
- isolate pylorus
- full-thickness longitudinal incision
- place stay sutures at center of incision and orient transversely
- close incision transversely
full thickness
Pyloromyotomy vs. pyloroplasty:
What is acquired pyloric stenosis (chronic hypertrophic pyloric gastropathy)? In what dogs are they most common?
muscoal and/or muscular hypertrophy of the pylorus
- small breeds: Lhasa Apso, Shih Tzu, Maltese
- excitable or vicious
- males > females
- middle-aged to older
What are the 3 suggested etiologies of acquired pyloric stenosis? What history is most commonly seen?
- gastrin secretion
- increased stress
- drugs/trauma
- intermittent vomiting
- vomiting frequency increases over time
- dietary modification affects frequency
What is seen on radiographs and ultrasounds in patients with acquired pyloric stenosis?
RADIOGRAPHS: gastric distension with delayed gastric emptying
ULTRASOUNDS: pyloric wall and muscle thickness (muscularis < 4 mm; pyloric wall < 9 mm)
What is and isn’t able to be seen on endoscopy in patients with acquired pyloric stenosis?
able to visualize hypertrophy of the mucosa and biopsy it to rule out neoplasia
cannot visualize muscular layers
What are the 3 grades of acquired pyloric stenosis? What determines them?
- muscular hypertrophy
- muscular and mucosal hypertrophy
- mucosal hyperplasia and muscular/submucosal inflammation
ultrasound
What are the 4 treatment options for acquired pyloric stenosis?
- transverse pyloroplasty
- Y-U pyloroplasty
- billroth 1
- biopsy
What does the Y-U pyloroplasty achieve? What 3 things does this result in?
transposes antral wall to pyloric region
- deforms pyloric outflow and creates a wider pylorus
- shortens gastric emptying time
- allows mucosal resection
How can better exposure be gained when performing a Y-U pyloroplasty? What should be avoided?
transection of the gastrohepatic ligament
hepatoduodenal ligament - can damage the common bile duct
What is a Billroth 1? When is it performed?
pylorectomy with gastroduedenostomy
severe outflow obstruction with grade 3 pathology
How is a Billroth 1 performed? What needs to be performed if the common bile duct is damaged?
- excise the pylorus after ligating blood supply
- end-to-end anastomosis
cholecystoduodenostomy or cholecystojejunostomy
What are 2 advantages and 3 disadvantages to performing Billroth 1?
ADVANTAGES - abnormal tissue completely removed, larger increase in gastric outflow
DISADVANTAGES = technically difficult, longer procedure, increased risk of leakage
What are the most common malignant gastric neoplasias? Specifically in cats?
- adenocarcinoma
- leiomyosarcoma
- mast cell tumors
- fibrosarcomas
lymphoma
What are the most common benign gastric neoplasia?
- leiomyoma
- adenoma
- adenomatous polyp (bleeding)
What are the most common signs of gastric outflow obstruction?
- vomiting, regurgitation, hematemesis
- anorexia
- melena: black stool
- pain
- weight loss
- abdominal distension
(may be asymptomatic)
What are the most common lab findings associated with gastric outflow obstruction?
nonspecific anemia, acidosis, hypochloremia, hypokalemia
What dogs are predisposed to gastric adenocarcinoma?
- Rough-coated Collies
- Staffordshire Terriers
- Belgian Shepherds
(males > females; 7-10 y/o)
Where are gastric adenocarcinomas most commonly found? How do they act?
pyloric antrum or lesser curvature
metastasis to regional lymph nodes, liver, and lungs common
What are 4 common pathologies associated with gastric adenocarcinomas?
- diffuse, thickened and nondistensible
- linitis plastica - leather bottle stomach
- ulcerate mucosal plaques
- discrete polypoid
How is gastric adenocarcinoma diagnosed on radiographs? What 4 things are seen?
contrast abdominal radiographs ( +/- thoracic rads for metastasis)
- filling defects
- delayed gastric emptying
- loss of normal rugal folds
- mucosal thickening
What is seen on ultrasounds when diagnosing gastric adenocarcinomas?
- mural thickening
- loss of normal wall
- diminished to absent local motility
- lymph node/liver evaluation or biopsy for grading
What is the preferred test for diagnosing gastric adenocarcinoma?
endoscopy —> very diagnostic and can take biopsies
How are gastric adenocarcinomas treated? What if it is non-resectable and obstructive?
- aggressive surgical excision with > 5 cm margins
- remove regional lymph nodes for biopsy and staging
palliative bypass procedure by gastrectomy or Billroth 1/2
What are 4 indications for gastrectomies? How are they done?
- neoplasia
- ischemic injury (GDV)
- ulcer
- trauma
ligate vessels or use a TA stapler, providing wide borders, and close like a gastrotomy
What is a Billroth 2? What is the most common indication?
partial gastrectomy of the pyloric region and proximal duodenum with gastrojejunostomy to allow extensive removal of damaged tissue without tension on suture
when resection of stomach is so proximal to limit end to end anastomosis
What are 3 complications associated with Billroth 2 procedures?
- alkaline gastritis - bile and pancreatic secretions flow into the stomach
- blind loop syndrome - gastric contents move orally and putrefy
- marginal ulceration - jejunal mucosa is not used to acidic contents
What is the major advantage to Roux-en-Y anastomosis? What 2 problems still remain?
avoids alkaline reflux gastritis and decreases likelihood of blind loop syndrome
- marginal ulceration
- requires one more anastomosis
What is the origin of gastric leiomyosarcoma? In what aged animals are they most common? Where are they found?
smooth muscle of the stomach (white muscle)
middle-aged —> around 7 years old
cardia
How do gastric leiomyosarcomas act? What do they commonly cause?
slow growing —> often an incidental finding in patients older than 15 y/o, can do submucosal resection
gastric outflow signs
What causes oomycosis in the stomach? Where is this a problem? What dogs are most afftected?
Pythium insidiosum, an aquatic parasite
Southeastern, Gulf Coast states from CA to OH in the fall and winter months
young, large breed working dogs (Labs)
How does Pythium insidiosum affect the stomach? What clinical signs are associated?
infiltrates the submucosa and muscularis layers of the stomach and small intestines with a rapid growth rate and extensive nature +/- palpable abdominal mass and increased mesenteric LNs
weight loss, vomiting, diarrhea, and hematochezia
What are the 2 most common diagnostics used for Pythiosis?
- histopathology - eosinophilic pyogranulomatous inflammation found on a deep tissue sample of fibrotic material
- ELISA for antibodies
How is Pythiosis treated? What combined medical treatment is recommended?
surgical excision with 3-4 cm borders with monitoring of ELISA for recurrence within 2-3 months post-op
- Itraconazole and Terbinafine (ergosterol inhibitors)
- Capsofungin and Anidulafungin (beta-glucan inhibitors)
- immunotherapy with vaccine
