PATHOLOGY - Gastric Dilatation Volvulus Flashcards
What is gastric dilatation volvulus (GDV)?
Gastric dilatation voluvulus (GDV) is the dilatation of stomach with gas and fluid and the rotation of the stomach resulting in complete gastric outflow obstruction
Describe how the stomach rotates in a gastric dilatation volvulus (GDV)?
In a gastric dilatation volvulus (GDV), the stomach tends to rotate clockwise on the longitudinal axis, moving the pylorus ventrally and to the left, and the fundus to the right
https://www.youtube.com/watch?v=JaAN-6FrPTM
What are the risk factors for gastric dilatation volvulus (GDV)?
Breed
Previous gastric dilatation volvulus (GDV)
First degree relative that has had a gastric dilatation volvulus (GDV)
Diet
Exercise directly after meals
Stress
Age
Which signalement is more prone to gastric dilatation volvulus (GDV)?
Large, deep chested dogs
List some examples of dog breeds which are more prone gastric dilatation volvulus (GDV)
Great Danes
St Bernards
Gordon Setter
Irish Setter
Weimaraner
Basset Hound
Which dietary habits increase the risk of gastric dilatation volvulus (GDV)?
Fewer large meals
Rapid eating
Smaller kibble size
(T/F) Gastric dilatation volvulus (GDV) is common in younger dogs
FALSE. Gastric dilatation volvulus (GDV) is least common in dogs under 2 years old, however is most common in dogs over 7 years old
What is the pathophysiology of a gastric dilatation volvulus (GDV) regarding the stomach?
Due to the dilatation of the stomach, the gastric blood vessels can be stretched and avulsed and the intraluminal pressure can increase which reduces blood flow to the stomach. This reduced blood flow can cause gastric inschaemic and necrosis. Furthermore, reduced blood flow to the gastric mucosa will impair the protective mucus barrier of the stomach, exposing the mucosa to gastric acid which can result in ulceration. This reduced blood flow to the stomach also allows bacteria and endotoxins to enter the bloodstream and cause septic and endotoxic shock
Remember GDV also compresses caudal vena cava which reduces blood flow
What is the pathophysiology of a gastric dilatation volvulus (GDV) regarding the cardiovascular system?
Gastric dilatation volvulus (GDV) impairs venous return to the heart through compression of the caudal vena cava, reducing cardiac output resulting in decreased circulating blood volume which can progress to hypovolaemia and hypovolaemic shock which can even result in myocardial ischaemia. This reduces the blood flow to the stomach which results in ulceration, ischaemia, necrosis and septic and endotoxic shock. GDV also causes compression of the hepatic portal vein resulting in venous congestion of the intestinal tract
Which arrhythmias can be seen in patients with gastric dilatation volvulus (GDV)?
Ventricular premature contractions (VPCs)
Ventricular tachycardia
What is the pathophysiology of a gastric dilatation volvulus (GDV) regarding the respiratory system?
Gastric dilatation volvulus (GDV) decreases the functional residual capacity of the lungs as the stomach will compress the diaphragm
What is the pathophysiology of a gastric dilatation volvulus (GDV) regarding the spleen?
The spleen is attached to the stomach via the gastrosplenic ligament so the spleen is displaced concurrently, causing splenic vascular occlusion, congestion, and splenomegaly and potentially splenic ischaemia and necrosis
What are the clinical signs of gastric dilatation voluvulus (GDV)?
Acute onset abdominal distension with hyperesonance on percurssion
Non-productive vomiting
Hypersalivation
Dyspnoea
Clinical signs of hypovolaemia
What are the clinical signs of hypovolaemia?
Weak peripheral pulses
Prolonged capillary refill time (CRT)
Pale mucous membranes
Tachycardia
How do you diagnose a gastric dilatation volvulus (GDV)?
History, clinical signs and the clinical examination will be very good indicators that this is a gastric dilatation volvulus (GDV), however radiography can be used for confirmation
Which radiograph view should you use to diagnose a gastric dilatation volvulus (GDV)?
Right lateral recumbency
What are the key signs of a gastric dilatation volvulus (GDV) on radiography?
Gas filled, distended stomach
Rotation of the stomach (pylorus will be dorsal and the fundus will be ventral)
Compartmentalisation lines (C-lines)
Sometimes small intestinal dilatation
How do you treat a gastric dilatation volvulus (GDV)?
Stabilisation followed by surgical intervention
What is the first thing you should do when you are presented with a gastric dilatation volvulus (GDV) patient?
Stabilisation of the patient
Do this even before radiography
What are the first forms of stabilisation you should carry out when presented with a gastric dilatation volvulus (GDV) patient?
Intravenous fluid therapy
Gastric decompression
What is the aim of intravenous fluid therapy when stabilising a gastric dilatation volvulus (GDV)?
The aim of intravenous fluid therapy is to restore the circulating blood volume and improve tissue perfusion
How should you carry out intravenous fluid therapy in patients with gastric dilatation volvulus (GDV)?
Place two large bore cephalic catheters (can use jugular or central line if this can’t be done) and do a shock dose of intravenous fluids. Re-assess the cardiovascular parameters and repeat doses if needed (the doses can be repeated up to four times)
What is the canine shock dose of intravenous fluids?
90ml/kg/hr over 15 minutes
Which veins should you not use for intravenous fluids when stabilising a GDV patient?
Saphenous veins as due to the compression of the caudal vena cava, the fluids will not be able to return to the heart effeciently
What is the aim of gastric decompression when stabilising a gastric dilatation volvulus (GDV)?
Gastric decompression is done to prevent gastric necrosis, improve cardiac output and reduce dyspnoea
What are the two methods of gastric decompression?
Orogastric (stomach) tubing
Percutaneous decompression
Orogastric (stomach) tubing is the best
How do you carry out orogastric tubing?
Have your patient in a sitting position and place a vetwrap roll into their mouth as a gag. Pass a well-lubricated large-bore orogastric tube through the hole in the middle of the vetwrap roll. Remove all air and fluid from the stomach and lavage the stomach. Repeat orogastric decompression as needed during the stabilisation period
Orogastric tubing is the first line method for gastric decompression
How do you carry out percutaneous decompression?
If orogastric decompression is not possible, clip and sterile prep a tympanic area of the right flank, and insert either a 14, 16 or 18 gauge needle to begin decompression. Following percutenous decompression, a subsequent attempt to pass the orogastric tube is often successful
What further stabilisation is required following intravenous fluids and gastric decompression?
Intravenous antibiotics
Oxygen supplementation
Analgesia
Anti-arrhythmic drugs
Which antibiotics should you use for a gastric dilatation volvulus (GDV)?
Co-amoxiclav
Cefuroxime
Which analgesic drugs should you use for a gastric dilatation volvulus (GDV)?
Full mu agonist opioid - remember GDV is very painful and required surgery
When are antiarrhythmic drugs indicated in a gastric dilatation volvulus (GDV) patient?
Antiarrhythmic drugs are indicated if ventricular premature contractions (VPCs) intefere with cardiac output or if there is ventricular tachycardia
Which antiarrhythmic drugs should be used in gastric dilatation volvulus (GDV) patients?
Continuous rate infusion (CRI) of lidocaine
What are the goals of gastric dilatation volvulus (GDV) surgery?
Repositioning of the stomach
Assessing if the stomach is viable
Gastropexy
Assessing if the spleen is viable
What are the steps involved in repositioning the stomach?
- Carry out a ventral midline laparotomy
- Establish the direction of stomach rotation (usually anticlockwise but you should always check)
- Identify the duodenum and follow it to the pylorus
- Gently lift the pylorus towards the right and push the fundus down to the left
- Feel the cardia of the stomach to ensure it is definitely untwisted
- Ask an assistant to place an orogastric tube so you can carry out gastric decompression
Watch the video on moodle in M16.W2
What is a key sign that the stomach has rotated in a clockwise direction?
If the omentum completely covers the stomach when you open the abdomen, this is a key sign that the stomach has rotated clockwise
How does a normal, viable stomach appear?
Pink in colour
Blanches easily but rapidly re-colours
Periastalsis
Bleeds well on cut surface
Pulsation at the gastric vessels
How does a compromised stomach appear?
Red/erythematous
What should be done if the stomach is compromised?
Gastric invagination
What is gastric invagination?
Gastric invagination is where you make in incision in the compromised region of the stomach and invaginate it using a cushing or lambert suture pattern on the seromuscular layer. Any non-viable, necrotic tissue will be sloughed off and viable tissue will survive
How does a non-viable stomach appear?
Black/green/purple/blue in colour
No peristalsis
No bleeding on cut surface
No pulsation at the gastric vessels
Palpable thinning of the gastric wall
What should be done if the stomach is non-viable?
Partial gastrectomy however be aware that resection of over 25% of the stomach reduces the stomach capacity
What is a gastropexy?
A gastropexy is a surgical technique which anchors the stomach to the abdominal wall to prevent rotation
Which gastropexy method should be used for a gastric dilatation volvulus (GDV)?
Right incisional gastropexy
What are the steps involved in a right incisional gastropexy?
- Make a 5-6cm ventral incison through the transverse abdominus on the right abdominal wall. The incision should be 5cm from the linea alba and caudal to the ribs
- Make a corresponding incision through the seromuscular layer of the pylorus (feel for the seperation of the submucosa and mucosa from the seromuscular layer)
- Using a simple continuous suture pattern, suture the cranial borders of the abdominal wall and pylorus incisions moving from dorsal to ventral. Repeat the same for the caudal edges of the incision
Which suture material should you use for a gastropexy?
Monofilament absorbable suture material such as polydiaxonone (PDS)
What is the rate of recurrence of a gastric dilatation volvulus (GDV) if a gastropexy is not performed?
80% recurrence rate if a gastropexy is not performed
When is a splenectomy indicated following a gastric dilatation volvulus (GDV)?
Persistent splenic congestion 10 minutes after repositioning the stomach
Avulsion of the splenic vessels
Gross splenic necrosis
What are some of the potential post operative complications of a gastric dilatation volvulus (GDV)?
Ventricular arrhythmias for up to 72 hours post-op
Gastric wall necrosis (will present as sepsis)
Peritonitis (will present as sepsis)
What are some of the potential long term complications of a gastric dilatation volvulus (GDV)?
Gastric hypomobility
Recurrence of gastric dilatation (but not volvulus if a gastropexy has been performed)
What should you make owners aware of when their pet is being treated for gastric dilatation volvulus (GDV)?
High risk surgery
Pet will be in ICU for several days post-operatively
