Stomach Flashcards
According to Baron 2020 in Vet surg what was the most common incisional complication following laparoscopic assisted gastropexy?
Seroma. Odds of complication twice as high in dogs undergoing single port lap assisted procedures as compared to double port.
According to Duffy 2021 in Vet Surg, which of the following gastrectomy closure techniques was associated with the lowest leakage pressures?
1) Stapled (4.8mm TA)
2) Double layer inverting closure
3) Stapled with reinforced Cushing suture pattern.
Stapled.
Stapled with reinforced Cushing suture pattern had 3 x increase in leakage pressures. Double layer inverting had 3x increase in maximum leakage pressure, 4.5 times initial leakage pressure.
In a study by Lhuillery 2022 in Vet Surg, was immediate (<5 hours) or delayed (>5 hours) surgical intervention for GDV associated with improved mortality risk? What was one prognostic factor identified for survival in both groups?
No difference in survival between immediate and delayed groups.
The presence of hyperlactatemia after 24-hours of fluid therapy was associated with an increased risk of mortality.
In a study by White 2021 in JAVMA, what was the mortality rate for patients undergoing staged, delayed treatment for GDV? What factors were associated with mortality rate?
9% mortality rate.
Factors associated with non-survival included gastric necrosis, increased or percentage change in lactate.
In a study by Velay 2024 in JAVMA, was there any difference in outcome using either double layer inverting, double layer simple continuous, or a single layer simple continuous pattern for gastrotomy closure?
No difference between groups
In a study by Zuercher 2021 in VRU, CT was successful in identification of what proportion of gastric neoplasms as compared to ultrasound?
91% v. 69%.
CT also identified more lymphadenopathy and was more accurate in location of the gastric mass as compared to ultrasound.
Based on a study by Tanaka 2022 in VRU, what are the expected findings on CT for a benign pyloric lesion (adenoma, hyperplasia, polyposis) v. a malignant neoplasm (GIST, adenocarcinoma)?
Benign lesions typically formed mass lesions of the mucosal layer. With malignant lesions the outer layer of the wall was thickened. In cases of adenocarcinoma lymphadenomegaly was consistently observed.
What condition is depicted in the attached radiograph from a case series by Bahlmann 2022 in JFMS?
Gastric diverticulum
Successfully treated in the majority of cases by partial gastrectomy.
Maine Coon cats appear to be over-represented.
In a study by Abrams 2019 in Vet Surg, what was the MST in dogs undergoing surgical excision of gastric carcinoma? What was associated with improved survival?
MST was 178 days.
Adjunctive chemotherapy was associated with improved survival (intraoperative complications were associated with increased risk of death).
Major complications occurred in 8/40 dogs, of which 4 were septic peritonitis due to dehiscence.
In a study by Webb 2019 in Vet Surg, did both the length and number of suture lines affect the biomechanical properties of a gastropexy in a canine cadaveric model?
1 or 2 suture lines had no effect on the biomechanical properties.
4cm as compared to 2cm gastropexies led to increased load to failure.
In a study by Pavlova 2019 in Vet Surg, what 4 factors were associated with development of gastroduodenal ulceration in dogs?
NSAID or glucocorticoid administration, mechanical obstruction, neoplasia.
Working dogs also seemed to be predisposed.
Describe the vascular supply of the stomach.
What is the innervation of the stomach?
The parasympathetic fibers of the vagus nerves and sympathetic fibers of the celiac plexus.
What are the layers of the stomach?
Mucosa, submucosa, muscularis (inner circular, oblique and longitudinal), serosa.
What are the glands of the stomach?
Cardiac (serous), pyloric (mucous) and gastric.
Gastric glands can be further divided into Chief, parietal, endocrine, mucus neck, surface epithelium (see image).
What are the consequences of prolonged gastric fasting?
Decreased gastric pH, higher incidence of gastroesophageal reflux, unreliable reduction in gastric size. Shorter fasting pre-operative may be preferable (fed a small meal 3-hours prior to surgery).
In what percentage of anesthetized patients is the esophagus exposed to an acidic environment?
50%
Can the hepatogastric and hepatoduodenal ligaments be transected if required for improved gastric exposure?
Yes.
What closure techniques are recommended for gastric closure?
2 layer inverting, or appositional closure of the mucosa and submucosa followed by an inverting layer. Two layer appositional closures have also been described.
Which of the following suture materials is the least resistant to gastric acid?
1. Polyglyconate (Maxon)
2. Polydioxanone (PDS)
3. Poliglecaprone 25 (Monocryl)
PDS, half life of 12 days in gastric fluid, as compared to 75 days for Maxon, and 15 days for Monocryl.
Is oversewing of the staple line recommended when gastrectomy is performed using GIA stapling devices?
Yes - oversewing with a continuous inverting pattern is recommended.
Aside from a routine ventral midline celiotomy, what other abdominal approach can be used for access to the stomach?
Paracostal
What subjective criteria can be used to assess gastric wall viability? What are some objective measure techniques that have been described?
Thickness, colour, peristalsis, perfusion.
Objective measurement techniques include fluroscein staining (58% accurate), laser Doppler flowmetry (consistent with subjective findings of the surgeon), scintigraphy (79% accurate).
What might be used to aid in repair of full-thickness gastric defects with inadequate functional luminal diameter?
Autologous intestinal submucosal grafts.
What are some disadvantages of gastric wall invagination?
Gastric ulceration and hemorrhage, abscess formation, obstruction secondary to sloughing of large amounts of tissue.
What are some described gastropexy techniques?
Belt-loop, circumcostal, incisional, incorporating, laparoscopic, laparoscopic assisted, endoscopic assisted, grid technique, gastrocolopexy.
What is the strength of commonly performed gastropexy techniques?
On which side is the gastropexy performed in instances of hiatal hernia?
Left sided. Care should be taken not to penetrate the gastric lumen when incising the seromuscular layer of the fundus because the gastric wall is not as thick in this area.
What gastropexy technique is depicted?
Incisional
What gastropexy technique is depicted?
Belt loop
What gastropexy technique is depicted?
Circumcostal
Is a full thickness seromuscular incision used for gastrocolopexy?
No - both the surfaces of the greater curvature of the stomach and transverse colon are scarified. It is unknown whether a permanent adhesion is created.
How is an incorporating gastropexy performed?
5cm of the pyloric antrum is incorporated into the cranial third of the linea alba closure. No incision is made into the seromuscular layer of the stomach. Strength of the adhesion formed has not been evaluated.
What are 3 methods by which attachment between the stomach and the transversus abdominus can be achieved during laparoscopic gastropexy?
Intracorporeal suturing, staple assist device, endo-GIA stapling through subserosal tunnels in the pyloric antrum and right body wall.
What are the disadvantages of the Fredet-Ramstedt pyloromyotomy?
Does not allow visualization of the gastric mucosa, relieve obstructions associated with mucosal or submucosal disease, or allow for full thickness biopsy of the stomach wall.
Which of the following pyloric surgical techniques are full thickness?
1) Fredet-Ramsted
2) Heineke-Mikulicz
3) Y-U pyloroplasty
Heineke-Mikulicz pyloroplasty and Y-U pyloroplasty. The Fredet-Ramsted technique is a pyloromyotomy technique.
When performing a Fredet-Ramsted pyloromyotomy which layers of the stomach are incised?
The seromuscular layer, allowing the mucosa/submucosa to bulge through the incision.
Which pyloric surgical technique is depicted?
Which pyloric surgical technique is depicted?
Which pyloric surgical technique is depicted?
What is the name for a pylorectomy and gastroduodenal anastomosis?
Billroth I
What are some indications for Billroth I?
Pyloric neoplasia, severe ulceration, pyloric hypertrophy. 1-2 cm margins should be obtained for suspected neoplastic disease.
During Billroth I procedure care has to be taken to preserve which structures?
The bile duct and pancreatic ducts. A minimum of 5-10mm of healthy tissue should be maintained between the duodenal excision and the opening of the bile duct to prevent obstruction. The bile duct can be stented if swelling is a concern.
Which vessels are ligated during a Billroth I procedure?
Branches of the right gastric and gastroepiploic. The hepatogastric ligament can be transected to improve visualization if required.
How is closure of a Billroth I procedure performed?
One or two layer appositional closure (no difference in leakage between closure techniques reported).
What are the two primary complications after Billroth I surgery?
Hypoalbuminemia (63%), anemia (58%).
Decreased survival is reported in cases of malignant neoplasia or pre-operative weight loss.
What is a Billroth II procedure?
Partial gastrectomy with gastrojejunal anastomosis. Concurrent cholecystoenterostomy is often required.
What are the four types of hiatal herniation?
Type 1: sliding (intermittent movement of the gastroesophgeal junction into the thoracic cavity).
Type 2: paraesophageal (fundus of the stomach herniates through the hiatus).
Type 3: components of type 1 and 2.
Type 4: herniation of organs other than the stomach into the thoracic cavity.
What are the most frequently reported breeds with congenital sliding hiatal herniation?
Shar-Peis and English bulldogs. Signs usually develop between 2-4 months of age.
What are some causes of acquired sliding hiatal hernia?
Trauma or secondary to upper airway disease (BOAS, laryngeal paralysis).
What are some sequelae of hiatal herniation?
Esophagitis and secondary megaesophagus, aspiration pneumonia.
What imaging techniques are useful for the diagnosis of hiatal herniation?
Thoracic radiographs +/- contrast may be useful for type 2 herniation. Typically type 1 herniation requires videofluoroscopy due to the dynamic nature of the disease. Esophagoscopy may also be used and can help to document concurrent esophagitis.
What is the function of prokinetic agents (metoclopramide and cisapride)?
Increase the rate of gastric emptying and enhance lower esophageal sphincter tone, decreased pyloric sphincter tone.
What medical management options are described for hiatal herniation?
Gastroprotectants (famotidine, pantoprazole, sucralfate), prokinetics, dietary modification (feeding low fat diet from a height).
What is the surgical treatment for hiatal herniation?
Phrenoplasty, esophagopexy and left-sided gastropexy. The left triangular ligament must be transected to adequately retract the left liver lobes and visualize the esophageal hiatus.
If circumferentially incising the phrenicoesophageal ligament care must be taken to avoid transection of the vagal nerve trunks and esophageal vessels. It will also induce pneumothorax.
How is a esophagopexy performed?
A 3cm partial thickness incision is made in the left side of the esophagus to the level of the muscularis. A second incision is made in the superficial seromuscular layer of the left diaphragm and the pexy is performed.
What can occur if overreduction of a hiatal hernia occurs?
Regurgitation. This can be confirmed via contrast esophagography and requires reoperation.
What are some conditions that are thought to predipose to gastroesophageal intussusception?
Megaesophagus, abnormal esophageal motility, laxity of the esophageal hiatus.
What is the most common breed affected by gastroesophageal intussusception?
German shepherds (50% of cases) - congenital megaesophagus more common in this breed. 75% of dogs were less than 3 months of age.
What are the most common clinical signs associated with gastroesophageal intussusception?
Regurgitation and vomiting are most common.
In acute cases respiratory distress can also occur secondary to the physical presence of the stomach +/- aspiration pneumonia.
What imaging techniques can be used for the diagnosis of gastroesophageal intussusception?
Thoracic radiography +/- contrast (care must be taken to avoid aspiration in vomiting dogs), esophagoscopy.
What is the surgical treatment for gastroesophageal intussusception?
Generally considered a surgical emergency. Ventral midline approach allows reduction. Left sided or left and right sided gastropexy should be performed to prevent recurrence.
What is the prognosis for gastroesophageal intussusception?
Early mortality rates were 95%, but may be improved now. Megaesophagus may not resolve.
What is the proposed pathogenesis of pyloric outflow hypertrophy in brachycephalic dogs?
Thought to be secondary to chronic air dilation of the stomach leading to excessive release of gastrin and gastric acid, production of cholecystokinin and secretin, with a trophic effect on the antral and pyloric mucosa.
Has also been reported as a congenital condition in brachycephalic dogs under 1 year of age (termed pyloric stenosis).
Is acquired hypertrophic pyloric gastropathy more common in females or males?
Males, typically in small breed dogs (Shih Tzus, Maltese, Lhasa Apsos).
What diagnostics are recommended in cases of hypertrophic pyloric gastropathy?
Radiography may suggest the disease if gastric emptying exceeds 8 hours. Ultrasound can be used to assess for thickness, and endoscopy is useful in visualizing mucosal hypertrophy +/- biopsies to rule out neoplasia.
What are surgical treatment options for hypertrophic pyloric gastropathy?
Pyoloromyotomy (Fredet-Ramsted procedure) if only the muscularis is involved. Heineke-Mikulicz or Y-U pyloroplasty if the mucosa/submucosa is involved. Billroth I may be required in severe cases.
What is the prognosis for hypertrophic pyloric gastropathy
Good for benign cases.
In what percentage of cases with gastric foreign body is hypochloremia present?
50%
What are the most common gastric neoplasms of dogs and cats?
Dogs: Adenocarcinoma
Cats: lymphosarcoma
Sarcomas, stromal tumours, lymphoma, benign masses and pythium are also reported in dogs.
What are the three forms of gastric adenocarcinoma?
Diffuse (linea plastica), ulcerated mucosal plaques, discrete polypoid mass.
They most commonly affect the pyloric antrum or the lesser curvature of the stomach.
Are male or female dogs more commonly affected by gastric adenocarcinoma?
Male dogs.
In what percentage of dogs with gastric adenocarcinoma is metastasis reported?
70-80%
Regional lymph nodes, liver and lungs are the most common sites.
What is the difference between leiomyosarcoma and GISTs?
Leiomyosarcoma originates from the smooth muscle cells, whereas GISTs originate from the interstitial cells of Cajal.
GISTs are c-kit positive, which may affect treatment (i.e. use of tyrosine kinase inhibitors).
What is the MST for canine gastric lymphoma?
17 days
What is the prognosis for cats with GI lymphoma?
Depends on the type. May have a good prognosis with low-grade (well-differentiated, small cell lymphoma; MST 704 days).
What are the potential causes of gastric ulceration?
Renal disease: decreased clearance of gastrin.
Hepatic disease: decreased degradation of gastrin, derangement of gastric blood flow through portal hypertension or thrombosis of gastric vessels.
NSAIDs: direct effect of acidic drug on the gastric mucosa, inhibition of COX and protective prostaglandins (affects mucosal blood flow, mucus production, bicarb secretion, and epithelial turnover).
Glucocorticoids, and neoplasia.
When is medical management of gastric ulceration preferred over surgical intervention?
When the underlying cause can be corrected, blood loss is not life threatening, and the ulcer is not in danger of immediate perforation.
What is the mechanism of action of famotidine, omeprazole, sucralfate, and misoprostol in the treatment of gastric ulceration?
Famotidine (or ranitidine, cimetidine): H2 receptor antagonist. Effectiveness decreases within days.
Omeprazole (or pantoprazole): proton pump inhibitor, preventing H+ ions from entering the gastric lumen. Complete suppression of gastric acid within 3-5 days.
Sucralfate: forms a thick paste like substance that binds electrochemically charged proteins in the base of ulcers, forms a protective barrier, stimulates the release of prostaglandin locally.
Misoprostol: synthetic analogue of prostaglandin E1, increases bicarb secretion, mucus production and mucosal blood flow. Half life is less than 30 minutes.
Which of the following H2 receptor antagonists is the most potent - famotidine, ranitidine or cimetidine?
Famotidine, then ranitidine, then cimetidine.
What does surgical treatment of gastric ulceration entail?
Resection and full thickness biopsy, or serosal patch if perforation not imminent and viability of the gastric wall is the primary concern.
What is the most common cause of gastric perforation?
NSAID use or neoplasia.
Distant neoplasms such as gastrinoma or systemic mastocytosis can also trigger perforation.
In cases of gastric perforation secondary to suspected neoplasia, what margins should be performed?
Resection with 2cm margins. Sampling of the regional lymph nodes and liver biopsy also recommended.
Is endoscopy accurate in the detection of gastric perforation?
Potentially not, only 17% of gastric perforations detected by endoscopy in one study.
What are some specific risk factors that have been identified for GDV?
Large or giant breed dogs, increased thoracic depth to width ratio, GDV in a first degree relative, aggressive, small food particle size, exercise after a meal, stretched hepatogastric ligament, feeding fewer meals per day, eating rapidly.
Large or giant breed dogs with gastric foreign bodies reportedly 5 x more likely to develop GDV.
The role of splenectomy remains uncertain.
What are the pathophysiologic sequelae of GDV?
- Blood flow: Decreased venous blood flow and cardiogenic shock. Portal hypertension and venous stasis, mucosal death and bacterial translocation from the GI. Impaired hepatic reticuloendothelial function. Impaired respiration.
- Cardiac dysfunction: inadequate coronary blood flow and myocardial depressant factor results in myocardial ischemia and cardiac arrhythmias.
- Gastric wall necrosis: Capillaries collapse secondary to intragastric pressure with secondary necrosis. Avulsion of the short gastric arteries might contribute.
- Bacterial translocation
- Reperfusion injury
What lactate values have been used as predictors of survival in GDV?
Several studies:
1. Lactate values of >6.0 mmol/L and >7.4 mmol/L have been used with around 50% sensitivity and 80% specificity for survival.
- Lactate <9.0 mmol/L 90% predictive of survival in another study.
- Change in lactate might be useful: survival rates lower (23%) for dogs with post-treatment lactate of >6.4mmol/L, absolute changes of less than 4mmol/L (10%), or a percentage change in lactate of 43% or less (15%).
What degree of gastric rotation is most common with GDV?
180 to 270 degrees
Which area of the stomach is most commonly non-viable in GDV?
The greater curvature in the area of the fundus and the body.
What are some potential complications following GDV?
Peritonitis, sepsis, DIC, ileus, vomiting.
What is the reported recurrence rate of GDV following common gastropexy procedures?
Circumcostal: 4%
Incisional and belt-loop: 0%
Gastrocolopexy: 3/20 dogs
Incorporating: 4/61 dogs
What factors have been associated with mortality following GDV?
Clinical signs for >6 hours, concurrent gastrectomy or splenectomy, presence of hypotension, gastric necrosis, pre-operative cardiac arrhythmias, peritonitis, sepsis, DIC.
Interestingly an increased duration for presentation to surgery associated with decreased mortality.
Reported survival ranges from 73-90%.
What percentage of dogs with a myoglobin concentration <168 ng/mL survived following GDV?
90%
At risk dogs that have undergone prophylactic gastropexy have a ___-fold decrease in mortality?
29-fold
