Emergency Surgery: Gastric Dilation Volvulus (GDV)

• Notes on emergency surgeries

Gastric Dilation Volvulus (GDV)

• GDV involves swelling from gaseous distension and stomach rotation on its mesenteric axis.
• Dilation refers to the stretching of an organ beyond its normal dimensions.
• Torsion is the twisting of the stomach.
• Volvulus is torsion of the stomach greater than 180 degrees, causing it to rotate clockwise.
• Simple gastric dilation is gastric dilation without the volvulus
• Bloat does not distinguish between simple gastric dilation and GDV.
• GDV is a life-threatening surgical emergency.
• GDV primarily occurs in deep-chested, large breed dogs, but can affect any age, especially middle-aged to older dogs.
• Exact cause is unknown but often follows ingestion of large meals and strenuous exercise.
• Diet, amount of food ingested, feeding frequency, and feeding behavior are contributing factors
• Other contributing factors include anatomic predisposition, ileus, trauma, foreign bodies, primary gastric mobility disorders, vomiting and stress.
• Clinical signs include severe abdominal distension, restlessness, hypersalivation, abdominal pain (arched back), non-productive attempts to vomit, and signs of shock.
• GDV physical exam findings include depressed mentation, pale mucous membranes, prolonged CRT, cool extremities, rapid weak pulses, and arrhythmias

Pathophysiology

• Obstructive shock can occur, where compression of vessels by the distended abdomen decreases venous return and cardiac output.
• Untreated obstructive shock can lead to cardiac collapse and death.
• Cardiac arrhythmias can occur due to endotoxin release and decreased venous return to the heart.
• Hypotension is also a sign.
• On X-ray, a double bubble is typically visible

Stabilization

• The first step is to stabilize the patient and reverse shock by placing large bore catheters in cephalic or jugular veins, administering shock rates, and providing analgesics and oxygen.
• Bloodwork is also important
• The second step is to decompress the stomach by addressing aerophagia, bacterial fermentation, or metabolic reactions.
• Decompression can be achieved through orogastric intubation, by measuring the tube from the nose to the tip of the xiphoid process or trocarization.
• Trocarization points are at the point of greatest distension on the left side using a needle.

Surgical Approach

• Clip the abdomen from the xiphoid process to the pubis, prepping lateral aspects for a gastric feeding tube or closed suction drain if needed.
• Instruments needed include Balfour retractors, army-navy retractors, extra towel clamps, sterile lap sponges, heated lavage fluid (sterile saline), and suction.
• The approach involves a standard exploratory laparotomy

During Surgery

• Decompress the stomach to make de-torsion easier with an 18-gauge needle and a large syringe, applying gentle pressure while pulling the plunger.
• Reposition/De-torse the stomach with the surgeon on the right side of the dog, locating the pylorus and pushing down under the fundus.
• An orogastric tube may be needed to empty stomach contents with gentle warm tap water lavage.
• Assess viability of the stomach and spleen.
• Assess the stomach for color, thickness, motility, and edema, performing a partial gastrectomy if necrosis is evident, and if in doubt, cut it out.
• Examine splenic vessels for thrombosis and check if firm, enlarged, black and green.
• Initially examine then reassess after complete explore and gastropexy and perform a splenectomy if not viable.

Post-operative Care

• Intensive monitoring is needed, often for VPCs.
• Continue IV therapy and provide analgesics.
• Monitor for tachyarrhythmias and treat post-op emesis with anti-emetics and post-op ileus with metoclopramide CRI.
• Some vets trend to get eating as soon as possible, while others wait 12-24 hours.

Gastropexy

• Gastropexy permanently affixes the stomach to the body wall and can be an elective procedure.
• It prevents recurrence of GDV.
• The goal is to create permanent adhesion between the gastric serosa and the peritoneal surface of the right lateral body wall.
• For permanent adhesion, the gastric muscle must contact the body wall muscle.
• Techniques include incisional gastropexy, belt loop gastropexy, tube gastropexy, and laparoscopic gastropexy.

Hemoabdomen

• Hemoabdomen involves blood in the abdominal cavity

Clinical Signs

• Sudden weakness/lethargy, tachycardia, pale gums, distended abdomen with fluid wave, acute anorexia, weak pulses, and hypotension.
• Golden Retrievers are over-represented but can happen in any breed, middle age to older dogs

What to Do

• Provide oxygen support, perform bloodwork (CBC, full chemistry, coagulation profiles if not due to trauma, and PCV/TP), start IV fluids, perform abdominocentesis, and take thoracic radiographs pre-op.
• A PCV below 20% may require a blood transfusion pre- or intra-op

Indications for Splenectomy

• Hemoabdomen
• Neoplasia: hemangiosarcoma (dogs), mast cell tumor (cat).
• Trauma: lacerations, torsion.
• Infection, immune-mediated disease, IMHA or thrombocytopenia

Splenectomy and Splenectomy Surgery

• Splenomegaly is enlargement of the spleen.
• Splenectomy is the removal of spleen.
• Partial splenectomy is the removal of part of spleen
• Splenectomy is most commonly performed with neoplasia, splenic torsion, or severe trauma.
• Isolate spleen after full abdominal exploration
• Ligate and transect all vessels at splenic hilus with absorbable suture material or use LDS stapler or ligature.
• Always check for bleeding and close the abdomen routinely

Post-Operative Monitoring and Prognosis

• Hemorrhage is a major post-op complication, so monitor heart rate, mucous membrane CRT, pulses, blood pressure and PCV/TP.
• Provide oxygen support, and analgesia, and perform ECG
• Prognosis depends on the reason for a hemoabdomen.
• Hemangiosarcoma prognosis: 19-86 days with no chemo and 10% live a year following, adjunct chemotherapy increase survival times and hematoma and torsion
• Good prognosis

Auto-Transfusion

• Auto-transfusion may be considered such as in traumatic, for a hemoabdomen that will not result in a transfusion reaction.
• Perform only if no suspected uroabdomen, sepsis, peritonitis, or hemangiosarcoma.

Feeding Tubes

• Feeding tubes are used to provide nourishment, treat malnourishment, and minimize derangement and catabolism of lean body tissue

Signs and Predispositions for Malnourishment

• 10% Recent weight loss
• Poor hair coat
• Muscle wasting
• Signs of poor wound healing
• Anorexia for more than 3 days
• Serious underlying disease such as Trauma, Sepsis, Peritonitis, Pancreatitis and GI surgery
• Large protein loss from prolonged vomiting Diarrhea and draining wounds

Methods of Nutritional Support

• Enteral (GI nutrition), which includes all forms of oral feeding and is most convenient and physiologically sound.
• Maintains intestinal structure and function at a lesser expense.
• Parenteral is delivered via IV nutrition made up of carbohydrate source (dextrose), a protein source and fat source, delivered through a dedicated catheter.
• Use if Vomiting severe malabsorptive disorders, severe ileus

Feeding Tube Selection

• Nasoesophageal (NE tube) and Nasogastric (NG tube)- Both use for short term, inexpensive and easy to place, requires no anesthesia, and uses a liquid diet.
• Some animal will not eat with the tube.
• Small diameter tubes (cats, small dogs = 3.5-5fr, medium to large dogs 8-10fr).
• X-ray to check: NE tube level of carina and NG tube last rib.
• Esophageal (E-tube)-Long term, inexpensive, easy to place, can use calorically dense diets. Requires general anesthesia
• Cellulitis can occur if tube is removed early and can be used immediately
• Gastronomy (G-tube)-Long term, easy to place, and can use calorically dense diet. Requires anesthesia and laparotomy.
• There is a risk of peritonitis if the tube leaks or is removed early.
• The tube should be inserted to the level of the last rib, and must wait 12-24 hours after insertion to start feeding
• Percutaneous endoscopically guided (PEG tube)-Long term, can use calorically dense diet, requires anesthesia and endoscopy.
• The is a risk of peritonitis if the tube leaks or is removed early
• The tube should be inserted to the level of the carina and must wait 12-24 hours after insertion to start feeding
• Jejunostomy (J tube)-Long term, bypasses stomach and pancreas.
• May be used in patients with pancreatitis requiring anesthesia and laparotomy
• How to care for a feeding tube

Proper care for Tubes

• Requires liquid diet
• Peritonitis can occur if tube is removed early
• Before and after each feeding- Fill with 5-10 ml of water to prevent clogging and inspect tube to ensure it is in the correct place.
• If clogging occurs- Use a syringe with warm H2O by applying pressure and suction with syringe and instilling carbonated beverages.
• Feed calculated amount slowly and initially every 4-6 hours. If well tolerated, decrease frequency and increase amount.
• Stop feeding patient with any signs of nausea and discomport.
• Flush with H2O, replace clamps and ports when feeding is complete and medications can be given via these tubes.
• Continue to provide patient with oral food, use warm damp cloth to remove discharge from stoma.
• Change bandage Weekly, end of feeding tube should be incorporated into the bandage and apply e-collar to prevent accidental removal.

Notes on Gastric Dilation Volvulus (GDV), a life-threatening surgical emergency involving stomach swelling and rotation, primarily in large, deep-chested dogs. The exact cause is unknown but often follows ingestion of large meals and strenuous exercise. Diet, amount of food ingested, feeding frequency, and feeding behavior are contributing factors.