PATHOLOGY - Gastric Dilatation Volvulus

Question 1

What is gastric dilatation volvulus (GDV)?

Answer 1

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

Question 2

Describe how the stomach rotates in a gastric dilatation volvulus (GDV)?

Answer 2

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

Question 3

What are the risk factors for gastric dilatation volvulus (GDV)?

Answer 3

Breed
Previous gastric dilatation volvulus (GDV)
First degree relative that has had a gastric dilatation volvulus (GDV)
Diet
Exercise directly after meals
Stress
Age

Question 4

Which signalement is more prone to gastric dilatation volvulus (GDV)?

Answer 4

Large, deep chested dogs

Question 5

List some examples of dog breeds which are more prone gastric dilatation volvulus (GDV)

Answer 5

Great Danes
St Bernards
Gordon Setter
Irish Setter
Weimaraner
Basset Hound

Question 6

Which dietary habits increase the risk of gastric dilatation volvulus (GDV)?

Answer 6

Fewer large meals
Rapid eating
Smaller kibble size

Question 7

(T/F) Gastric dilatation volvulus (GDV) is common in younger dogs

Answer 7

FALSE. Gastric dilatation volvulus (GDV) is least common in dogs under 2 years old, however is most common in dogs over 7 years old

Question 8

What is the pathophysiology of a gastric dilatation volvulus (GDV) regarding the stomach?

Answer 8

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 inschaemia 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

Question 9

What is the pathophysiology of a gastric dilatation volvulus (GDV) regarding the cardiovascular system?

Answer 9

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. GDV can also result in arrhythmias which will also constribute to decreased cardiac output

Question 10

Which arrhythmias can be seen in patients with gastric dilatation volvulus (GDV)?

Answer 10

Ventricular premature contractions (VPCs)
Ventricular tachycardia

Question 11

What is the pathophysiology of a gastric dilatation volvulus (GDV) regarding the respiratory system?

Answer 11

Gastric dilatation volvulus (GDV) decreases the functional residual capacity of the lungs as the stomach will compress the diaphragm

Question 12

What is the pathophysiology of a gastric dilatation volvulus (GDV) regarding the spleen?

Answer 12

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

Question 13

What are the clinical signs of gastric dilatation voluvulus (GDV)?

Answer 13

Acute onset abdominal distension with hyperesonance on percurssion
Non-productive vomiting
Hypersalivation
Dyspnoea
Clinical signs of hypovolaemia

Question 14

What are the clinical signs of hypovolaemia?

Answer 14

Weak peripheral pulses
Prolonged capillary refill time (CRT)
Pale mucous membranes
Tachycardia

Question 15

How do you diagnose a gastric dilatation volvulus (GDV)?

Answer 15

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

Question 16

Which radiograph view should you use to diagnose a gastric dilatation volvulus (GDV)?

Answer 16

Right lateral recumbency

Question 17

What are the key signs of a gastric dilatation volvulus (GDV) on radiography?

Answer 17

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

Question 18

How do you treat a gastric dilatation volvulus (GDV)?

Answer 18

Stabilisation followed by surgical intervention

Question 19

What is the first thing you should do when you are presented with a gastric dilatation volvulus (GDV) patient?

Answer 19

Stabilisation and gastric decompressionof the patient

Do this even before radiography

Question 20

What are the first forms of stabilisation you should carry out when presented with a gastric dilatation volvulus (GDV) patient?

Answer 20

Intravenous fluid therapy
Gastric decompression

Question 21

What is the aim of intravenous fluid therapy when stabilising a gastric dilatation volvulus (GDV)?

Answer 21

The aim of intravenous fluid therapy is to restore the circulating blood volume and improve tissue perfusion

Question 22

How should you carry out intravenous fluid therapy in patients with gastric dilatation volvulus (GDV)?

Answer 22

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)

Question 23

What is the canine shock dose of intravenous fluids?

Answer 23

90ml/kg/hr over 15 minutes

Question 24

Which veins should you not use for intravenous fluids when stabilising a GDV patient?

Answer 24

Saphenous veins as due to the compression of the caudal vena cava, the fluids will not be able to return to the heart effeciently

Question 25

What is the aim of gastric decompression when stabilising a gastric dilatation volvulus (GDV)?

Answer 25

Gastric decompression is done to prevent gastric necrosis, improve cardiac output and reduce dyspnoea

Question 26

What are the two methods of gastric decompression?

Answer 26

Orogastric (stomach) tubing Percutaneous decompression | Orogastric (stomach) tubing is the best

Question 27

How do you carry out orogastric tubing?

Answer 27

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

Question 28

How do you carry out percutaneous decompression?

Answer 28

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

Question 29

What further stabilisation is required following intravenous fluids and gastric decompression?

Answer 29

Intravenous antibiotics Oxygen supplementation Analgesia Anti-arrhythmic drugs

Question 30

Which antibiotics should you use for a gastric dilatation volvulus (GDV)?

Answer 30

Amoxicillin Clavulanic acid Cefuroxime

Question 31

Which analgesic drugs should you use for a gastric dilatation volvulus (GDV)?

Answer 31

Full mu agonist opioid - remember GDV is very painful and required surgery

Question 32

When are antiarrhythmic drugs indicated in a gastric dilatation volvulus (GDV) patient?

Answer 32

Antiarrhythmic drugs are indicated if ventricular premature contractions (VPCs) intefere with cardiac output or if there is ventricular tachycardia

Question 33

Which antiarrhythmic drugs should be used in gastric dilatation volvulus (GDV) patients?

Answer 33

Continuous rate infusion (CRI) of lidocaine

Question 34

What are the goals of gastric dilatation volvulus (GDV) surgery?

Answer 34

Derotation of the stomach Assessing if the stomach is viable Gastropexy Assessing if the spleen is viable

Question 35

What are the steps involved in derotating the stomach?

Answer 35

1. Carry out a ventral midline laparotomy 2. Establish the direction of stomach rotation *(usually anticlockwise but you should always check)* 3. Identify the duodenum and follow it to the pylorus 4. Gently lift the pylorus towards the right and push the fundus down to the left 5. Feel the cardia of the stomach to ensure it is definitely untwisted 6. Ask an assistant to place an orogastric tube so you can carry out gastric decompression | Watch the video on moodle in M16.W2 ## Footnote https://uofglasgow.zoom.us/rec/play/whlEkG6Mxi_VCN-Hj1K7mbm2UFKXH6oncnNyZpmkXhAPHKgEFxhAk3Y18TAolAau8beWAYtXwGccgd7Y.PmV6WaP9eFGWCQX4?accessLevel=meeting&canPlayFromShare=true&from=share_recording_detail&startTime=1606757894000&componentName=rec-play&originRequestUrl=https%3A%2F%2Fuofglasgow.zoom.us%2Frec%2Fshare%2FGRVeS3oVK7m6C_RDoXdekY6PhSkiWzEmwHksXi6dfIfbVmFYqRk7fMDZm7ysJlcR.zKIxKYGInGN-h7ia%3FstartTime%3D1606757894000

Question 36

What is a key sign that the stomach has rotated in a clockwise direction?

Answer 36

If the omentum completely covers the stomach when you open the abdomen, this is a key sign that the stomach has rotated clockwise

Question 37

How does a normal, viable stomach appear?

Answer 37

Pink in colour Blanches easily but rapidly re-colours Periastalsis Bleeds well on cut surface Pulsation at the gastric vessels

Question 38

How does a compromised stomach appear?

Answer 38

Red/erythematous

Question 39

What should be done if the stomach is compromised?

Answer 39

Gastric invagination

Question 40

What is gastric invagination?

Answer 40

Gastric invagination is where you fold in the compromised region of the stomach 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

Question 41

How does a non-viable stomach appear?

Answer 41

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

Question 42

What should be done if the stomach is non-viable?

Answer 42

Partial gastrectomy however be aware that resection of over 25% of the stomach reduces the stomach capacity

Question 43

What is a gastropexy?

Answer 43

A gastropexy is a surgical technique which anchors the stomach to the abdominal wall to prevent rotation

Question 44

Which gastropexy method should be used for a gastric dilatation volvulus (GDV)?

Answer 44

Right incisional gastropexy

Question 45

What are the steps involved in a right incisional gastropexy?

Answer 45

1. 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 last rib 2. Make a corresponding incision through the seromuscular layer of the pylorus *(feel for the seperation of the submucosa and mucosa from the seromuscular layer)* 3. 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 ## Footnote https://uofglasgow.zoom.us/rec/share/hdQdlw-4hT7uvB7HHpr4Gz3MRlZbEsN51NuWcxGhqiot72Nd-6PX7DvIKaMYKwWn.LKFt2FD0hPajIcHW?startTime=1606756754000

Question 46

Which suture material should you use for a gastropexy?

Answer 46

Monofilament absorbable suture material such as polydiaxonone (PDS)

Question 47

What is the rate of recurrence of a gastric dilatation volvulus (GDV) if a gastropexy is not performed?

Answer 47

80% recurrence rate if a gastropexy is not performed

Question 48

When is a splenectomy indicated following a gastric dilatation volvulus (GDV)?

Answer 48

Persistent splenic congestion 10 minutes after repositioning the stomach Avulsion of the splenic vessels Gross splenic necrosis

Question 49

What are some of the potential post operative complications of a gastric dilatation volvulus (GDV)?

Answer 49

Ventricular arrhythmias for up to 72 hours post-op Gastric wall necrosis *(will present as sepsis)* Peritonitis *(will present as sepsis)*

Question 50

What are some of the potential long term complications of a gastric dilatation volvulus (GDV)?

Answer 50

Gastric hypomobility Recurrence of gastric dilatation *(but not volvulus if a gastropexy has been performed)*

Question 51

What should you make owners aware of when their pet is being treated for gastric dilatation volvulus (GDV)?

Answer 51

High risk surgery Pet will be in ICU for several days post-operatively