Surgical Management of GI Tract Tutorial

Question 1

What are the 2 most common causes of small bowel obstruction?

Answer 1

• Evidence of previous abdominal operation

- Evidence of a strangulated external hernia

Question 2

What does vomiting suggest?

Answer 2

• Obstruction of small intestine usually accompanied by early & profuse vomiting
• This tends to be late, or absent, in large bowel obstruction.

Question 3

Why does a grossly distended abdomen suggest a large bowel or low obstruction?

Answer 3

-Because of size of LB, distension of abdomen is usually marked

Question 4

What conservative management is effective in treating the majority of patients with a sigmoid volvulus?

Answer 4

1. A sigmoidoscope is passed with the patient lying in the left lateral position.
2. A large well lubricated, soft rubber rectal tube is passed along the sigmoidoscope.
3. This usually untwists the volvulus, with release of vast quantities of flatus & liquid faeces

Question 5

What could suggest acute mesenteric ischemia (AMI)?

Answer 5

• Elderly patient who is an ex-smoker – ↑ed risk of cardiovascular disease
• Short history
• Central pain with guarding
• No previous abdominal scar or hernia
• No bowel sounds
• Poor general condition
• ↑ed serum lactate

Question 6

What does a exploratory laparotomy involve?

Answer 6

• Midline incision.
• Evaluate the abdominal viscera
• If obvious intestinal necrosis – resection of the affected bowel loops.

Question 7

What is damage control laparotomy?

Answer 7

• Stapled off bowel ends may be left in discontinuity

* Re-inspect after a period of continued ICU resuscitation to restore physiological balance.

Question 8

How is there restoration of blood flow in SMA?

Answer 8

• Embolectomy of SMA – in embolic AMI
• Endovascular management of SMA thrombus – in thrombotic AMI
• Arterial bypass of SMA - in thrombotic AMI

Question 9

What are arterial causes of AMI?

Answer 9

• Embolism (50%)
• Thrombosis (20-35%)
• Non occlusive (<5%)

Question 10

What are the venous causes of AMI?

Answer 10

Superior mesenteric vein thrombosis (10-15%)

Question 11

What are embolism sources?

Answer 11

1. From left auricle - atrial fibrillation.
2. A mural infarct.
3. Atheroma from aorta or aneurysm.
4. Endocarditis vegetations.
5. Left atrial myxoma.

Question 12

What does a thrombosis do?

Answer 12

1. Blocks origin of superior mesenteric artery & can cause ischaemia of full length of small bowel.
2. Due to atherosclerosis
3. Often all main splanchnic vessels—coeliac, superior & inferior mesenteric arteries

Question 13

What are nonocclusive causes of AMI?

Answer 13

1. Due to hypotension/hypoperfusion.
2. Due to vasospasm in shock—nonocclusive mesenteric ischaemia (NOMI).
3. Critically ill patients with vasopressor requirements
4. Those undergoing dialysis with large volume fluid removal

Question 14

How does superior mesenteric vein thrombosis cause AMI?

Answer 14

-Superior mesenteric vein thrombosis
•Occurs in patients with:
•Portal hypertension
•Portal pyaemia
•Sickle cell disease
-Related to the presence of an underlying hypercoagulable state e.g. obesity, pregnanacy, OCPs, some cancers