Ch 91 stomach Flashcards
anatomy
cardia, fundus, body, and pyloric portions
- incisura angularis (angular notch): protrusion midpoint of the lesser curvature that separates the antrum and the body (papillary process of the liver lies)
- pyloric sphincter, double muscle layer that surrounds it
- stomach wall four distinct layers; serosa, muscle, submucosa, and mucosa
- muscular composition three layers; longitudinal fibers, circular and oblique
omentum
- greater and lesser omentum are attached to the stomach at the greater and lesser curvatures
- splenic portion of the greater omentum forms the gastrosplenic ligament, through which the gastroepiploic vessels course to the stomach
- lesser omentum forms the hepatogastric ligamen
Vasculature, Lymphatics, and Innervation of the Stomach
arterial blood supply of the stomach originates from the celiac artery
- left gastric artery supplies the fundus of the stomach and lesser caurvature
- splenic artery > left gastroepiploic artery, which supplies the greater curvature (anastomoses with the right gastroepiploic artery)
- hepatic artery > right gastric artery, which supplies pylorus and pyloric antrum
Vasculature, Lymphatics, and Innervation of the Stomach
- venous drainage to the portal vein is through the splenic vein on the left and gastroduodenal vein on the right
- lymphatic drainage of the stomach is through the gastric and splenic lymph nodes
- innervated by parasympathetic fibers of the vagus nerves and sympathetic fibers of the celiac plexus
List the secretory cells of the stomach and what each produced
- Parietal (Body) - Acids and intrinsic factor (mucosal protein which binds B12 to allow its absorption in distal SI
- Mucous Neck (Body, Antrum) - Mucous
- Chief (Body) - Pepsinogen
- Epithelium - Mucous, bicarb
- Endocrine (Body) - Histamine, Gastrin, Serotonin
What is contractile retropulsion?
Pyloric closure prior to full antrum contraction, allowing liquid chyme to pass through but solids are forced retrograde back into body. Results in breakdown of digestible particles to 0.1-0.63mm prior to gastric emptying
motility
- After surgical resection of the fundus in dogs, the rate of gastric emptying of fluids is increased because of a resultant increase in pressure after the same change in volume.
By what process does gastric mucosa and submucosal ulcers heal?
Mucosa - Epithelial regeneration
Submucosal - Fibrotic repair
Healing is enhanced by its extensive and redundant blood supply
What tissues contribute to collagen formation in the stomach?
Fibroblasts and smooth muscle cells of the GIT
What are some negative effects of pre-surgical fasting?
What recommendation may be more appropriate?
Electrolyte, acid-base, and hydration status
- Decreased gastric pH
- Higher incidence of gastrooesophageal reflux
- Does not reliably decreased gastric content volume
Small amounts of canned food 3hr beore surgery may decreased gastric acidity and minimise occurance and clinical impact of gastrooesophageal reflux while having minimal to no impact on gastric content volume
STUDY: oesophagus is exposed to an acidic environment in >50% of anesthetized patients but that this event is clinically evident in only a small percentage of animals. This “silent” exposure > oesophagitis and stricture.
What anaethetic drugs can be used to decreased gastric secretion?
administration of prophylactic antibiotics
Anticholinergics such as atropine and glycopyrrolate
What ligaments can be transected to aid in visualisation of the dorsal aspect of the stomach?
Hepatogastric and hepatoduodenal ligaments
surgical considerations
- Minimizing the risk for and consequences of gastric content spillage is achieved by carefully packing off the stomach, Stay sutures of 2-0 or 3-0 monofilamen
- Separate instruments designated for the clean and the clean-contaminated portions of the procedure
- warmed lavage fluid (37-39C)
gastric closure
suture patterns
- continuous double-layer inverting closure
- first full thickness and the second line incorporates only the serosa and muscular layers.
- Alternatively, first may appose only the mucosa and submucosa, and the second line inverts the remaining layers of gastric tissue.
- Inverting patterns: Cushing, Connell, and Lembert patterns.
- pyloroplasty > interrupted or continuous appositional pattern that incorporates submucosa.
suture
- resists rapid degradation in the acid- and enzyme-rich environment
- last 14 days necessary to regain gastric wall strength
- Polydioxanone undergoes a rapid and significant loss of tensile strength in an acidic environment
- polyglyconate or poliglecaprone 25 in gastric surgery
staples
- thoracoabdominal (TA), gastrointestinal anastomosis (GIA), and skin staplers
- potential necrosis along the staple line > oversewing is recommended
Tomihata et al: What were the half lived of polyglyconate (Maxon), poliglecaprone 25 (Monocryl) and polydioxanone (PDS) in gastric juices?
Polyglyconate - 75d
Poliglecaprone 25 - 15d
Polydiaxonone 12d
List some methods of determining gastric wall viability
- Gastric wall thickeness
- Serosal colour
- Serosal capillary perfusion
- Peristalsis
- If questionable, seromuscular layer can be incised to assess arterial supply
Subjective criteria have an 85% accuracy
Objective data
- fluorescein dye injection,
- scintigraphy
- laser Doppler flowmetry
partial gastrectomy
- remove necrotic stomach wall or neoplasia
- of necrotic areas, the cut edges of the remaining gastric wall should be actively bleeding
- two-layer pattern using 2-0 or 3-0 absorbable suture
- linear stapler (e.g., thoracoabdominal or gastrointestinal anastomosis stapler). Use of staplers, while more expensive, permits closure of the gastric lumen before resection so that contamination is limited
- cut edges beyond the staple line are oversewn
Gastropexy
- creation of a permanent adhesion of the stomach to the adjacent body wall
- GDV, hiatial hernia
- key component to successful gastropexy is incision through the serosal and peritoneal surfaces and into the muscular portion of each
- made caudal to the last rib to prevent penetration of the diaphragm
- biomechanical testing for commonly used open gastropexy techniques are similar > interpret carefully because strength required to prevent development of GDV is unknown
list types of gastropexy (8)
incisional
belt-loop
circumcostal
endoscopically assisted
laparoscopic gastropexy
gastrocolopexy;
incisional gastropexy (grid approach)
incorporating gastropexy (within linea alba closure)
Incisional Gastropexy
- 4-5cm seromuscular incision in the gastric antrum
- peritoneum and the transversus abdominis muscle 2 to 3 cm caudal to the last rib
- appropriate anatomic site of the incision
- 2-0 monofilament absorbable suture in a simple continuous suture pattern
- no recurrence of GDV in 61 dogs = equivalent to belt-loop gastropexy and superior to circumcostal and gastrocolopexy.
- hiatal hernia: performed on the left side of the abdomen and fundus
Belt-Loop Gastropexy
- seromuscular flap from the pyloric antrum and passed through a tunnel in the abdominal wall
- flap is based along the greater curvature and incorporates branches of the gastroepiploic artery
- ## 4 cm long and 3 cm apart
Circumcostal Gastropexy, Gastrocolopexy, Incorporating Gastropexy
Circumcostal Gastropexy
- seromuscular flap may be double or single hinged.
- When a single-hinged flap is used, it is based from the lesser curvature
- eleventh or twelfth rib at the level of the costochondral junction
- pneumothorax or fracture of the rib; both are reported complications of this procedure
Gastrocolopexy
- Creation of a suture line between the greater curvature of the stomach and the transverse colon
incorporating gastropexy
- pyloric antrum wall incorprated with the cranial portion of the linea alba closure
- inadvertent penetration of the stomach while entering the abdominal cavity could occur in future ex laps
Minimally Invasive Prophylactic Gastropexy Techniques
(3)
Grid Approach
- minilaparotomy (paracostal approach)
- gastric antrum is retracted into the surgical field with Babcock intestinal forceps.
- Edges of the gastric incision are apposed to the cut edges of the transversus abdominis fasci
Endoscopically Assisted Gastropexy
- scope passed into the stomach, and insufflated.
- pyloric antrum is viewed endoscopically and stomach is stabilized with 2 percutaenous stay sutures immediately caudal to the thirteenth rib
- Unlike the grid dissection, muscle layers are transected, not bluntly dissected.
- gastric seromuscular incision are apposed to cut edges of the transversus abdominis muscles
Laparoscopic
- ports placed on the ventral midline
- A stay suture is introduced through the body wall, grasped intracorporeally, inserted through the pyloric antrum
- suture-assist device and laparoscopic needle holders, need for the surgeon to have training and experience
laparoscopic-assisted technique:
- scope used to identify stomach to be incorporated into the pexy, Laparoscopic Babcock forceps grasp, permitting a smaller exposure than the grid technique
- antrum through the body wall opening created for the port
What is the recommended port placement for laparoscopic gastropexy?
Three portal technique, all on ventral midline
- 1cm caudal to umbilicus
- Instrument port 3-4cm caudal to xyphoid
- Final port midway between first 2, directed medially towards proposed gastropexy site
Pyloromyotomy and Pyloroplasty
- focused on removing outflow obstruction and normalizing gastric outflow
- Conventional and laparoscopic pyloromyotomy and pyloroplasty have been described
- studies have reported no change to slowed gastric emptying after these pyloric procedures….
List the options for pyloroplasty (3)
Fredet-Ramstedt Pyloromyotomy
- Longitudinal incision through serosa and muscularis extending 1-2cm orad and aborad of the pylorus
- Allows protrusion of submucosal surface to protrude and enlarge
- Use limited - restriction must be limited to the serosa or muscularis layer
Heineke-Mikulicz Pyloroplasty
- Full thickness longitudinal incision centred on the pylorus and closed transversely
Y-U Pyloroplasty
- Y-shaperd full thickness incision with arms over the antrum/pylorus and body extending through pylorus and onto duodenum
- U-flap pulled aborally to close as a U
What is a Bilroth I?
Gastroduodenal Anastomosis
Pylorectomy and gastroduodenotomy
Bilroth I indications
- neoplasia confined to the pyloric region
- ulceration of the outflow tract
- some cases of pyloric hypertrophy
What structures must be identified and protected dueing a pyloroectomy?
- Bile duct (identified by manual expression of the gallbladder)
- Pancreatic ducts
- Vascular supply to the stomach and duodenum
common bile duct and its opening can be stented during sx
What is the prognosis of gastroduodenostomy (Bilroth I)
Study of 24 dogs:
- 18 survived 14 days
- 10 died by 3 months
- Hypoalbuminaemia (62.5%), anaemia (58.3%)
also depenedent on underlying dz
What is a Bilroth II?
Partial gastrectomy with gastrojejunal anastomosis
- Side-to-side anastomosis (openings of stomach and duodenum are closed, loop of jejunum is anastomosed to the greater curvature of the stomach)
- Cholecystoenterostomy usually required
- Prognosis very poor…
General Postoperative Considerations
- food and water may be initiated as early as 12 hours after surgery in patients that are not actively vomiting
- loss of intestinal motility is suspected, electrolytes (particularly potassium and magnesium) should be evaluated
- treatment with a prokinetic agent such as metoclopramide
- ileus, a nasogastric tube may be used to intermittently decompress the stomach and trickle feed the patient, which may stimulate gastric motility.
- feeding tube > nasoenteric tube
Hiatal Hernia
pathophys
- esophageal hiatus is formed by the musculature of the medial portion of the lumbar crus of the diaphragm
- hiatial hernia = organs herniate through the esophageal hiatus into the mediastinum
- Four types
Pathophysiology
- previously thought that increased intraabdominal pressure function as a “flutter valve” for the intraabdominal portion of the esophagus to prevent gastroesophageal reflux.
- dogs with hiatal hernia considered deficient of “flutter valve” because of displacement of the gastroesophageal junction into the thoracic cavity.
- however, Pratschke et al. showed that gastroesophageal anatomy in dogs is inconsistent and documented that 8 of 12 dogs examined had no abdominal portion of the esophagus.
- aquired hernia: Patients with upper respiratory obstruction have decreased intrathoracic pressure during inspiration that may contribute to esophageal reflux and hiatal herniation (BOAS)
pinchcock effect (hosgood)
- The crural muscle fibers of the diaphragm surrounding the esophageal hiatus generally form a sphincter-like structure that has a pinchcock effect.
- Contraction of crura at hiatus contributes to intraluminal pressure at the gastroesophageal junction and helps maintain gastroesophageal competence
- For GER and regurgitation to occur, there may be a failure in hiatal assistance with gastroesophageal competence
GER
cause remains unknown, multifactorial, factors involved include:
- sliding hiatial hernia
- reduced gastroesophageal junction pressure,
- esophagitis,
- obesity,
- increased distensibility of the gastroesophageal junction,
- prolonged esophageal clearance
- delayed gastric emptying
failure in hiatal assistance with gastroesophageal competence
List the 4 types of hiatal hernias
type I most common
- Type I: “Sliding” - Intermittent movement of gastrooesophageal junction into the thoracic cavity
- Type II: “Paraoesophageal” - The gastrooesophageal junction remains in a normal position and a portion of the fundus herniates beside the oesophagus
- Type III: Combination of I and II
- Type IV: Herniation of abdominal organs other than the stomach
What breeds are overrepresented for type I hiatial hernia?
Shar Peis
Eng Bulldogs
Diagnostics
- positive-contrast esophagram (gastro-oesophageal junction within thorax)
- Fluoroscopy is of benefit in cases of type I
- endoscopy - maneuver to increase the transdiaphragmatic pressure gradient during esophagoscopy (also see reflux esophagitis)
List potential medications used in the medical management of hiatal hernia
Reducing acid secretions
- H2 receptor blockers: ranitidine, cimetidine, famotidine
- H/K-ATPase inhibitor omeprazole
Oesophageal protection
- Sucralfate (polyaluminium sucrose)
Prokinetics
- Metoclopromide or cisapride (increase gastric emptying and enhance lower oesophageal tone)
Diet
- Low fat diet fed more frequently or from elevated height
8/15 dogs had complete resolution with medical management (trial recommended b4 sx, not as successful in congenital)
What are the main components of surgical correction of a hiatal hernia (3)?
Phrenoplasty
- hiatal reduction
- there are no set standards for hiatal diameter
- horizontal mattress sutures of 2-0 monofilament nylon dorsally and ventrally through the crura surrounding the esophageal hiatus without transection of the phrenicoesophageal ligament
- care not suture vagal n
Oesophagopexy
- partial-thickness incision in the left side of Oesophagus and sutured to diaphragm incision
Left-sided fundic incisional gastropexy
Prognosis is good!
left hepatic triangular ligament transected visualize esophageal hiatus
post hiatial-Sx
- monitored for dyspnea associated with pneumothorax
- Worsening of regurgitation after surgery from overreduction of the hiatus, which can be confirmed with contrast esophagography
What is gastrooesophageal intussusception?
What breed is overrepresented?
- Retrograde (orad) invagination of the stomach into the oesophagus without displacement of the gastrooesophageal junction
- GSD are overrepresented (over 50% of cases)
- More than 75% were in dogs younger than 3 months
gastrooesophageal intussusception
- cause of gastroesophageal intussusception is not well understood
- though to be predisposed by esophageal abnormalities, including megaesophagus, abnormal esophageal motility, and laxity of the esophageal hiatus
- Vomiting and regurgitation are the most common clinical signs
- majority of affected dogs have evidence of esophageal disease, including megaesophagus, enlarged esophageal hiatus, and abnormal esophageal motility.
dx
- invaginated stomach within the caudal esophagus > confirmed by endoscopy
- contrast esophagram
What is the recommended treatment of gastrooesophageal intussusception?
What is the prognosis?
- Ventral midline coeliotomy with reduction of intussusception and left sided +/- right sided gastropexy
- historically high Mortality rate 95% , More recent individual case reports are more promising
Hypertrophic Pyloric Gastropathy
- Anatomically based pyloric outflow obstructions
- congenital or acquired.
- Congenital (pyloric stenosis): generally muscular, in brachycephalic breeds < 1 year.
- Acquired: mucosal or a combination, small breeds
- BOAS have documented endoscopic diagnosis of pyloric mucosal hyperplasia and pyloric stenosis
CS
- intermittent vomiting +/- Regurgitation and hypersalivation dt esophagitis
Dx
- retention of gastric contents after a fast of greater than 8 hours on rads
- ultrasound (affected by pateint position)
- mucosal hypertrophy, endoscopic examination may be very helpful in making the diagnosis + biopsy
What is the hypothetised cause of hypertrophic pyloric gastropathy (pyloric stenosis) in brachycephalic breeds?
Chronic air dilation of the stomach (secondary to URT dz) cause increased intragastric pressure, secondary secretion of gastrin and gastric acid, resultant production of cholecystokinin and secretin which have a trophic effect on the antral and pyloric mucosa
Surgical treatment of benign pyloric outflow obstructions
- muscular hypertrophy alone > pyloromyotomy
- mucosal or combined > transverse (Heineke-Mikulicz) or Y-U pyloroplasty
- bilroth I (pyloric resection and gastroduodenostomy)
PX
- outcome after surgical correction of benign conditions of the pylorus is very good (>80% excellent)
Full-thickness biopsy of pylorus should be performed in every case
Gastric Foreign Body
- Endoscopic removal of gastric foreign bodies has become much more common and has variable success rates: one STUDY 10 of 36 dogs required subsequent gastrotomy
- Electrolyte and acid-base abnormalities are common secondary to the vomiting: hypochloremia is present in >50% of cases
- dx: important to avoid barium sulfate if gastric perforation is suspected (free abdominal air present)
- Ultrasonography
Complications
- esophagitis secondary to reflux and vomiting.
prognosis
- very good if there is no evidence of perforation.
- perforation > depends on the severity of peritonitis
What percentage of gastric FB may be visible on plain rads?
95%
Free peritoneal gas usually floats to the highest point within the abdomen. In lateral recumbency, this is usually under the caudal aspect of the ribs or in the midabdomen
What is the most common form of gastric neoplasia in the dogs?
What breeds are predisposed?
What is the reported metastatic rate?
What are the three morphological forms?
Gastric adenocarcinoma (42-90%)
Belgian Shepherd, Rough-coated Collie, Staffys
Metastatic rate 70%
Three forms:
- Diffuse infiltration (“linitus plastica”) - non-distensible, scirrhours stomach wall
- Groups of ulcerated mucosal plaques
- Discrete polypoid mass
occur most frequently in the pyloric antrum
Gastric neoplasia
ddx:
1. adenocarcinoma
2. sarcomas and stromal
GIST
leiomyosarcoma, fibrosarcoma, and gastric extramedullary plasmacytoma.
3. lymphoma
4. benign (Leiomyoma and adenomatous polyps)
5. fungus
dx
- imaging: dentification of possible metastatic disease. The cause, however, cannot be differentiated based on any imaging modality
- endoscopic examination and biopsy: may not adequately diagnose compared to full thikeness biopsy.
What is the most common form of gastric neoplasia in cats?
What is the prognosis?
Gastric lymphoma
Prognosis depents on grade. Low grade can have good prognosis with chemotherapy with MST 704d
Intermediate- and high- grade usually rapidly progressive and fatal
What are gastrointestinal stromal tumours?
Arise from the cells of Cajal
c-kit positive (differentiates them from lyomyosarcomas)
What is the prognosis of gastric neoplasia in dogs?
Poor…
- 2/21 dogs lived longer than 9 weeks with combo of Bilroth I/II, partial gastrectomy or no treatment
mets in 75%
Gastric Ulceration
Pathophysiology
Renal and hepatic disease
- Decreased hepatic degradation of gastrin and histamine
- Derangement of mucosal bloodflow due to portal hypertension and thrombosis
- Decreased renal clearance of gastrin?
NSAIDs and glucocorticoids
- 2 mechanisams (direct and systemic)
- COX-inhibition resulting in decreased PG production resulting in decreased mucosal bloodflow, epithelial mucous production, bicarb secretion and epithelial turnover.
- now believed that gastric injury secondary to NSAID administration is the result of combined COX-1 and COX-2 inhibition, interaction between NSAID and phospholipids, and subsequent uncoupling of mitochondrial oxidative phosphorylation
- Although COX-2 selective agents were developed to spare the prostaglandins beneficial for gastric mucosal protection, these COX-2 selective agents have also been associated with gastric ulceration
- Direct topical effect of weakly acidic and lipid-soluble NSAID on gastric mucosa
- Glucocorticoids exact mechanism, however, is unknown
and neoplasia
anemia from chronic blood loss into the gastrointestinal tract
List the main options for medical management of gastric ulcers
surgery?
aimed at decreasing gastric acidity and promoting mucosal protective mechanisms.
Histamine (H2) Receptor Blocker
- Cimetidine, ranitidine, famotidine
Proton pump inhibitors
- Omeprazole, pantoprazole (substituted benzimidazoles that covalently bind H/K-ATPase enzyme, blocking its activity)
- Absorbed in alkaline environment (proximal duodenum)
- Administed 1hr before a meal
Sucralfate
- In acidic environment dissociates. Octasulphate portion forms a thick paste that binds electrostatically charged proteins in the base of ulcers
- “Biological bandaid” - protective barrier, inactivates pepsin, absorbs bile acids
- stimulates local PG release
Misoprostal
- SYnthetic analogue of PGE1
- Increases bicarb secretion, mucous production and mucosal bloodflow
- Decreased H/K-ATPase pump activity via decreased intracellular cAMP
- Can help to prevent ulcer formation but does not have an effect on treating current ulcers
surgery
- removal and full-thickness biopsy
- partial gastrectomy vs Billroth I.
- Alternatively, a serosal patch to reinforce the gastric wall.
- Correction of the underlying cause is critical.
- ongoing medical mgmt
What is a gastinoma?
A non-beta pancreatic islet cell tumour, associated with hypersecretion of gastrin antral G cells, resulting in gastric hyperacidity and ulceration
Gastric Perforation
pathophys
- most often secondary to NSAID or neoplasia (primary or gastrinoma)
Dx
- radiography: loss of abdominal detail and free abdominal gas
- Abdominocentesis is indicated in animals with free peritoneal fluid (dx sepsis)
- ultrasound or scope
prognosis
- dependent on underlying cause, severity of peritonitis, and overall condition of the animal
In what percentage of cases does gastroscopy confirm gastric perforation in dogs and cats?
Only 17%
GDV
- life-threatening syndrome, large-breed, deep-chested dogs in which the stomach rotates on its axis, trapping air within its lumen.
- pylorus and proximal duodenum move ventrally and then cranially (hepatoduodenal ligament is stretched), then migrating from right to left, which creates a fold in the stomach,
- coming to rest on the left, dorsal to the esophagus
- Trapped air increases intragastric pressure, > decreases venous flow through the abdomen by direct compression.
- Portal hypertension, systemic hypotension, and cardiogenic shock result.
GDV Etiology
risk factors (8)
- not completely understood.
risk factors
1. purebred large or giant breed
2. increased thoracic depth-to-width ratio
3. relative with GDV
4. feeding fewer meals per day,
5. eating rapidly
6. increased hepatogastric ligament length
7. exercise or stress after a meal
8. +/- splenectomy (studies conflict)
- fact that gastropexy seems to prevent GDV supports that volvulus occurs before the dilatation (rotation prevent eructation and pyloric outflow)
- mechanism for gas entrapment in the stomach before rotation is not understood
- gastric dilatation without volvulus does occur after gastropexy in some dogs
Pathophysiology (5)
complex, with multiple organ systems impacted
Blood Flow
- Gastric distention increase intraabdominal pressure and decreases venous flow throughout the abdomen.
- venous return from the caudal vena cava is reduced > cardiogenic shock
- compression of the portal vein > portal hypertension > venous stasis, mucosal death and bacterial translocation throughout GIT
- Portal hypertension impact hepatic reticuloendothelial function > decreased clearance of bacteria and endotoxins
- Pressure on the diaphragm from the distended stomach makes inspiration more difficult and further decreases oxygen delivery.
Cardiac Dysfunction
- inadequate coronary vessel flow + myocardial depressant factor, results in myocardial ischemia.
- Resultant cardiac arrhythmias further decrease systemic perfusion.
- Electrocardiographic abnormalities are reported in 40% to 70% of dogs
- Concentrations of serum cardiac troponin, markers of myocardial ischemia, are increased in dogs with GDV
Gastric Wall Necrosis
- stomach wall capillaries are collapsed secondary to intragastric pressure > necrosis of the gastric mucosa
- Increased pressure + systemic hypotension = full-thickness gastric wall necrosis in some dogs.
Bacterial Translocation
- translocation occurs from gut that are poorly perfused, one study did not document increase in bacteremia in GDV cases (Perioperative antibiotic may have impacted the findings in this study)
Reperfusion Injury
- Reperfusion injury associated with correction stomach and return of normal blood flow has been documented
- oxidative stress and antioxidant capacity change with GDV
What percentage of dogs have ECG abnormalities?
40-70%
Diagnostics
CS
- abdominal distention, unproductive vomiting or retching, restlessness, and hypersalivation
- decompensatory shock include pale mucous membranes, bradycardia, cold extremities, depressed mentation, and hypothermia.
RADS
- right lateral recumbency to confirm the diagnosis
- pyloric malposition with entrapment of air within the pylorus and gastric fold
- Pneumoperitoneum (perforation vs iatrogenic centesis)
bloods
- CBC: [haem], stress leuk, thrombocytopaenia
- biochem: elevated liver kidney enzymes, electrolytes
- lactate: helpful in evaluating perfusion, monitoring resuscitation efforts, and possibly predicting survival > values of survivors and nonsurvivors overlap, and thus care must be taken when applying specific cutoff values to individual patients.
What outcomes have been associated with lactate concentration?
- Plasma lactate over 6mmol/L 88% specific and 61% sensitive for gastric necrosis. In same study, 99% of dogs with lactate below 6 survived vs 58% above 6
- Initial lactate cutoff 7.4mmol/L 82% accurate (50% sen, 88% spec) for gastric necrosis and 88% accurate (75% sen, 89% spec) for predicting outcome
- 90% of dogs with initial lactate of 9.0mmol/L or less survived
- Survival rates significantly increased in dogs with final lactate 6.4 or less (91% survival), absolule change in lactate of 4mmol/L or more (86% survival), percentage change in lactate of 42.5% or more (100% survival)
Preoperative Management
- directed at stabilizing patients before surgery.
Fluid therapy
- most critical component (patients are hypotensive)
- multiple IV access (ideallt CVC)
- ideal to provide rapid resuscitation with a crystalloid solution (expand intrvalscular volume) - NaCl, lactated Ringer’s or hypertonic saline 7%
- maintaining volume ideally with oncotic support….
- measuring the patient’s response to therapy using systemic parameters such as heart rate and blood pressure
Continuous electrocardiography
- Treatment of arrhythmias if they result in pulse deficits or poor peripheral perfusion or are likely to progress to fibrillation
- vasopressor therapy
- Oxygen supplementation (saturation of hemoglobin)
- Broad-spectrum antibiotic therapy
gastric decompression
- orogastric intubation (passage of the tube into the stomach may be difficult, ideally sedated or if moribound)
- percutaneous placement of an over-the-needle catheter or a trocar (area of greatest tympany)
Anesthesia
- preoxygenation
- rapid control of the airway at the time of induction
- avoidance of agents cardiovascular depressants or arrhythmogenic
- hydromorphone, propofol
- fentanyl-lidocaine CRI intraoperatively, will reduce MAC of inhalation agents
- position patient to reduce compression
lidocaine if arrythmias present
Surgery
Goals: reposition the stomach, remove necrotic tissue, and create a permanent adhesion
- decompressed completely with orotube before derotate
- Gastric rotation of 90 to 360 degrees has been reported, with rotation of 180 to 270 degrees most common > ID pylorus
- Palpation of the gastroesophageal junction should identify whether the stomach has been completely derotated.
- exploration of the abdomen is indicated to identify any other abnormalities
- stomach and spleen are then evaluated for viability
- necrosis common > greater curvature, fundus and body
- gastric wall thickness (as estimated by palpation), serosal surface color, presence of peristaltic waves, and bleeding after serosal incision were 85% accurate in determining gastric wall viability
- gastropexy
esophagus suctioned if reflux occurs.
complications post-op (5)
ensure adequate hydration; correcting electrolyte abnormalities; treating cardiac arrhythmia
- peritonitis,
- sepsis,
- DIC (plasma transfusion)
- ileus (metoclopramide or intermittent gastric decompression via a nasogastric tube)
- vomiting
What are the reported recurrence rates of GDV with an incisional, circumcostal or gastrocolopexy gastropexy?
Incisional: 0%
Circumcostal: 4.3%
Gastrocolopexy 3/20 (15%)
List factors which have an association with an increased mortality rate with a GDV
- Clinical signs for more than 6hr
- Gastrectomy
- Splenectomy
- Hypotension
- Gastric necrosis
- Pre-op arrhythmias
- Peritonitis
- Sepsis
- DIC
Overall survival 73-90%
positive predictors for improved survival
- increased duration presentation > surgery (decrease in mortality presumably reflects time spent stabilizing)
- preoperative plasma lactate concentration below 6.0 mmol/L was associated with a 99% survival rate in one study, or improvement of at least 4mmol/L
- cut point value for myoglobin of 168 ng/mL, almost 90% of dogs survived
What is the lifetime risk of dogs predisposed to the development of GDV?
4-37%
Prophylactic Gastropexy
- 29-fold decrease in mortality rate compared with dogs that had not undergone gastropexy
- Dogs underwent laparoscopic evaluation of the gastropexy site at 1 month (n = 10) and 6 months (n = 9) after the gastropexy technique. All dogs had confirmation of firm adhesion at the gastropexy site,
How do stapled laparoscopic gastropexies compare to open incisional gastropexies?
Stapled were significantly weaker at 7 days after surgery but were not different in mean tensile load to failure at 30 days post-op
de la Vega 2023 – outcomes and complications associated with prophylactic gastropexy
BMC
- 0.4% directly associated complications – hemorrhage (2/3), infection (1/3)
- no long-term gastric dilatation, GDV or GI signs
- gastropexy malpositioning and bowel entrapment not observed
Circumferential esophageal hiatal rim reconstruction
for treatment of persistent regurgitation
in brachycephalic dogs: 29 cases (2016–2019)
Hosgood 2021
Circumferential esophageal hiatal rim reconstruction involved apposition of the
medial margins of the left and right pars lumbalis dorsal to the esophagus
(reconstructing the dorsal margin) and ventral to the esophagus (reducing
the ventral hiatal aperture and completing the circumferential reconstruction) + oesophapexy
substantial laxity of the left and right pars lumbalis and failure
of dorsal coaxial alignment were observed
Long-term follow-up
information was available for 19 dogs: regurgitation had resolved in 16 dogs
and occurred once weekly in 3 dogs. No ongoing medication was required
for any dog.
Influence of length of incision and number of suture lines on the biomechanical properties of incisional gastropexy
Webb 2019
monnet
number of suture lines → no effect on strength (load to failure ~53.5N)
- longer incision → high load to failure (4cm 57.3N vs 2cm 49.7N)
Evaluation of a staged technique of immediate
decompressive and delayed surgical treatment
for gastric dilatation-volvulus in dogs
White 2021
41 dogs, retorspectiive
delayed surgery = initial decompression, delay by mean 22.3h (5.25-69.75)
→ 3/35 (9%) mortality rate
- time from presentation to surgery not associated with gastric necrosis or mortality
- single plasma lactate and %change lactate associated with gastric necrosis and mortality
- Intraoperative identification of gastric necrosis was associated
with nonsurviva
mortality rates reported for dogs undergoing immediate surgical correction of GDV (7.5% to 18%).
Finney and Jaboulay pyloroplasties for the treatment of benign gastric outlet lesions in dogs and cats: technique and outcome in 13 cases (2015-2024)
Maurice 2024
chronic hypertrophic pyloric gastropathy (n = 4), perforating pyloro-duodenal peptic ulcer (4), sub-obstructive pyloro-duodenal eosinophilic sclerosing fibroplasia (2) and antral or proximal duodenal obstructive mass (3)
Nine cases were treated using hand-sewn Finney pyloroplasty and four cases were treated using stapled Jaboulay pyloroplasty. No major complications were recorded
benign: congenital pyloric stenosis, acquired chronic hypertrophic pyloric gastropathy, benign or inflammatory masses and sclerotic lesions
one author reported up to 25% of cases having persistent vomiting after Heineke-Mikulicz pyloroplasty, suggesting
the persistence of a partial gastric outlet obstruction
Finney pyloroplasty
- side-to- side anastomosis between the gastric antrum, the pyloric area and the proximal part of the duodenum
Jaboulay
- side-to- side anastomosis between the gastric antrum and the proximal part of the duodenum, excepting pylorus is preserved,
- technically not a true pyloroplasty, but rather an antroduodenostomy that bypasses
the affected pylorus
Use of real-time near-infrared fluorescence to assess gastric viability in dogs with gastric dilatation volvulus:
A case-control study
Mullen 2024
Prospective clinical trial.
Animals: 20 dogs with GDV and 20 systemically healthy dogs
Subjective assessment diagnosed 17 viable and three nonviable GDVs.
Near-infrared imaging demonstrated nonviable gastric fluorescence
in 4 dogs (3 fundi/cardia; 1 fundus). The surgeon’s margins for
resection were altered in 3/20 dogs
Near-infrared fluorescence can identify histologically confirmed nonviable gastric tissue.
Clinical significance: These results provide enough evidence to support the
implementation of NIRF as an adjunct to gross examination of the gastric wall in dogs with GDV.
NIF showed more diseased tissue than subjective assessment in 3 dogs, and picked up one more (4/4 vs 3/4)
The second
hypothesis was accepted as the fundic fluorescence
intensity in GDV nonviable cases with histopathologicconfirmed
fundic necrosis was lower than GDV viable
cases.
use of inotropes
to correct intraoperative hypotension for other reasons may artifactually affect tissue fluorescence. Further
study on the effects of hypotension and inotropic use
on fluorescence pattern and intensity are warranted
allows for precise mapping of
tissue vascularity while also providing quantitative measures
of fluorescence.
Histopathology was not performed
in the remaining 16 GDV dogs with a fluorescence
pattern demonstrating defined blood vessels but
the survival of all 16 dogs for a minimum of 14 days postoperatively
supports the absence of irreversible gastric
wall necrosis in these dogs.
Safe gastric wall closure in dogs using a single-layer full-thickness simple continuous suture pattern
Velay 2023
60 dogs
Prospective, randomly assigned to 3 groups: double-layer inverting continuous pattern (DLI) , double-layer simple continuous pattern (DLS), full-thickness single-layer simple continuous pattern (SLS)
RESULTS
All dogs were discharged from hospitalization. The survival rate did not differ among the 3 groups 1 month postoperatively, and major complications were not observed.
CLINICAL RELEVANCE
Using a full-thickness single-layer pattern is a safe alternative for gastrotomy closure
Retrospectively, minor complications did arise and were reported for 8 dogs. All these complications were associated with celiotomy and not with gastrostomy
Grimes et al
In 38% of cases, dogs undergoing gastrointestinal surgery with preoperative peritonitis developed postoperative peritonitis, compared to only 6% when it was absent preoperatively. 15 out of 45 dogs died due to this condition. When all surgeries were considered, common risk factors for the development of septic peritonitis included preoperative septic peritonitis.11 Therefore, in cases with septic conditions, double-layer sutures are likely recommended.
larger study needed
Pet health insurance reduces the likelihood of presurgical
euthanasia of dogs with gastric dilatationvolvulus
in the emergency room of an Australian
referral hospital
S Anderson 2021
NZVJ
Of the 69 dogs for which insurance information could be obtained, 10 (14%) cases
were insured at the time of the GDV event and 59 (86%) cases were not. The majority of
non-insured dogs (37/59; 63 (95% CI=50–74)%) were euthanised before surgery, while none
(0 (95% CI=0–28)%) of the insured dogs were euthanised at that time
Euthanasia prior to treatment was most common cause of death in non-referred
dogs with GDV; such euthanasia was entirely absent in the cohort of dogs that were insured.
Clinical relevance: Financial considerations significantly contribute to mortality of dogs with
GDV presented to an emergency room. Financial
Retrospective analysis of 736 cases of canine gastric dilatation
volvulus
KK Song 2020
AVJ
460 dogs were surgically treated and 276 dogs were humanely killed.
survival rates of patients operated on by general surgeons and specialists were 81.7% and 88.7%, respectively
results suggested that admission time was statistically
significantly related to the survival rate. Dogs operated
on by specialist surgeons had a significantly higher survival rate
compared to those operated on by general surgeons. Clinicians
should aim to stabilise and complete surgical correction of GDV
as soon as possible to decrease the mortality.
Comparison of incisional gastropexy with and without addition of two full-thickness stomach to body wall sutures
Mann 2023
retrospective, clinical study
1 cranial and 1 caudal to the continuous suture line, going full thickness into the stomach to ensure engagement of submucosa
superiority of one technique over the other cannot be determined on the basis of this study.
Addition of two full-thickness simple interrupted sutures to standard incisional gastropexy increases gastropexy biomechanical strength
Yi Pan 2023
mann
acute strength (failure load and work to failure)
37 pig cadavers
The MIG had higher failure load and work to failure compared to SIG. All failures were caused by gastric tissue tearing.
CLINICAL RELEVANCE
The MIG is biomechanically superior to SIG and may provide more security
Transversus abdominis muscle
as a gastric or intestinal on-lay flap in
two dogs and one cat
Simpson and Hall 2021
supporting the gastrointestinal tract when
gastrointestinal tissue viability is questionable or resection is not feasible. Further prospective clinical
evaluation studies would be indicated to determine whether the muscle flap remains viable
Evaluation of staple line reinforcement after partial gastrectomy closure in an ex vivo canine model
Duffy 2021
reinforcement of staple line after partial gastrectomy → improved biomechanical
properties (improve resistance to leakage)
Partial gastrectomy constructs were assigned to one of three closure techniques (n = 8 per group): group 1, stapled closure with a 90-mm thoracoabdominal stapling device and a 4.8-mm staple cartridge; group 2, hand-sewn double-layer inverting suture closure with 3-0 glycomer 631; and group 3, staple line reinforcement with an inverting Cushing suture pattern.
Paramedian incisional complications after prophylactic laparoscopy-assisted gastropexy in 411 dogs
Baron 2020
- paramedian incisional complications in 78/411 (19%)
- seroma 12.4%, SSI 3.9%, excessive scar tissue 2.2%- resolution of complications in 75/78 (96.2%)
- odds of complications 2x for single-incision-port lap-assisted gastropexy vs multi-port
Primary repair of nonsteroidal anti-inflammatory drug-associated full thickness gastrointestinal ulcers in 11 dogs
Dobberstein 2022
retrospective
9/11 (82%) concurrent NSAID and CCS or higher dose/frequency/length of NSAID administration
- 8/11 (73%) survived to discharge
- all cases peritoneal effusion and peritonitis upon abdominal entry
- ulcer size and location not associated with mortality
- mortality: potential trend with hyperlactatemia; not associated with positive culture, associated with need for post-op vasopressors
Primary closure may be associated with a high success rate in dogs with full thickness gastroduodenal ulcers.
Inhibition of COX 1 is thought to account for most of the adverse effects seen with NSAID administration, such as gastrointestinal
ulceration and decreased platelet function;11
however, it was reported that administering COX 2-selective NSAIDs to rodents with gastric ulcerations resulted in delayed healing.7,12,14,29 Moreover, COX 2 preferential NSAIDs have been recently identified as the most common risk factor associated with gastroduodenal
ulcerations
ulcer treatment ACVIM consensus
- Monotherapy with an H2RA (ranitidine) given twice daily is inferior to PPI (omeprazole) treatment given twice daily in dogs and cats.
- Based on evidence from studies in humans and research animals, PPIs administered twice daily are superior to other gastroprotectants for treating acid-related GUE. Our consensus opinion is that PPIs should be tapered in dogs and cats after prolonged use of >3-4 weeks. (to avoid rebound hypersecretion)
- PPI may cause -ntestinal dysbiosis
- unknown if misoprostol is effective for preventing GUE associated with administration of other NSAIDs in dogs and cats. There is no evidence that misoprostol decreases GUE from glucocorticoids in dogs and cats.
- There is weak evidence in experimental animals, No evidence indicates that combining sucralfate with either a PPI or an H2RA for treatment of GUE is beneficial or indicated. Proton pump inhibitors are superior to sucralfate for management of GUE.
Proton pump inhibitors are superior to H2RAs, sucralfate, and misoprostol for most causes of GUE in people, and should be considered as standard of care for the medical treatment of GUE in dogs and cats.
Gastroesophageal reflux
during anesthesia is associated with 46%-65% of cases of benign esophageal stricture in dogs and represents the most common cause of high-grade esophagitis and stricture formation in dogs.193, 194 Relaxation of the lower esophageal sphincter (LES) is mediated by nonadrenergic noncholinergic pathways195 and has been shown to occur with the administration of injectable preanesthetic and inhalant anesthetic agents.196-198 The LES may be rendered incompetent by a sliding hiatal hernia, which often is accompanied by GER and can be exacerbated by increased inspiratory effort typical of brachycephalic breeds.
lack of empirical evidence in dogs and cats, but compelling evidence from studies in people,
- may be beneficial for prevention of esophagitis secondary to GER, particularly in animals when it is associated with an anesthetic procedure. Administration of PPIs does not decrease gastric reflux, but may prevent injury by increasing the pH of the refluxate.
Characteristics and long-term outcomes of dogs with gastroesophageal intussusception
Grimes 2020
presentation: 72% male, 33% GSD; 67% vomiting, 33% regurgitation; most common
- 10/36 (28%) euthanasia without treatment
- treatment (72%) - 25/26 surgical
- 23/26 (88%) survival to discharge → MST 995d
- 6/8 that had died by follow-up time died due to persistent regurgitation
- persistent regurg in 7/10 dogs with follow-up – reduced severity +/- dietary management
- acute clinical signs or previous dx of megaoesophagus associated with risk of
persistent regurg
Abrams 2019 – complications and outcome with surgery for gastric carcinoma in 40 dogs
- surgery: 28/40 partial gastrectomy, 9/40 Billroth I, 2/40 subtotal gastrectomy,
1/40 submucosal resection
- complications: major intra-op 3/40 (7.5%) → 3/3 septic peritonitis
major post-op 8/40 (20%) - 4/8 septic peritonitis after dehiscence
- metastasis at surgery in 45%, mPFI 54d, MST 178d, 1y survival 17.5%
- survival to discharge 85% → MST 190d
- risk factors for death: intraoperative complication
- improved survival: adjuvant chemotherapy
Zuercher 2021 – clinical, ultrasound and CT findings in dogs with gastric neoplasia
successful identification of tumors: CT 92%, U/S 69%
- CT more sensitive for identifying lymphadenopathy and location of tumours
Outcomes of dogs undergoing surgery for gastric dilatation volvulus after rapid versus prolonged medical stabilization
Lhuillery 2022
outcomes of GDV surgery after rapid (90min) vs prolonged (>5hr) stabilization
- immediate group → higher likelihood of death under anaesthesia
- survival rates: to discharge: immediate 70/89 (78.6%); delayed (82.2%)
1m post: immediate 68/89 (76.4); delayed 55/73 (75.34%) - hyperlactatemia 24hr after initiation of fluid therapy associated with increased mortality
- survival rates: to discharge: immediate 70/89 (78.6%); delayed (82.2%)
No survival benefit was detected as a result of proceeding to surgery after either a rapid or a prolonged medical stabilization.
