Chapter 47: Colon and Rectum- Sigmoid Volvulus

Question 1

What is it?

Answer 1

Twisting of colon on itself about its mesentery, resulting in obstruction and, if complete, vascular compromise with potential necrosis, perforation, or both

Question 2

What is the most common type of colonic volvulus?

Answer 2

Sigmoid volvulus (makes sense because the sigmoid is a redundant/“floppy”structure!)

Question 3

What is a sigmoid volvulus?

Answer 3

Volvulus or “twist” in the sigmoid colon

Question 4

What is the incidence?

Answer 4

≈75% of colonic volvulus cases

(Think: Sigmoid = Superior)

Question 5

What are the etiologic factors?

Answer 5

• High-residue diet resulting in bulky stools and tortuous, elongated colon
• chronic constipation
• laxative abuse
• pregnancy
• seen most commonly in bed ridden elderly or institutionalized patients, many of whom have history of prior abdominal surgery or distal colonic obstruction

Question 6

What are the signs/symptoms?

Answer 6

• Acute abdominal pain
• progressive abdominal distention
• anorexia
• obstipation
• cramps,
• nausea/vomiting

Question 7

What findings are evident on abdominal plain film?

Answer 7

Distended loop of sigmoid colon, often in the classic “bent inner tube” or“omega” sign with the loop aiming toward the RUQ

Question 8

What are the signs of necrotic bowel in colonic volvulus?

Answer 8

Free air, pneumatosis (air in bowel wall)

Question 9

How is the diagnosis made?

Answer 9

CT scan

sigmoidoscopy

or radiographic exam with Gastrografin® enema

Question 10

Under what conditions is Gastrografin® enema useful?

Answer 10

• If sigmoidoscopy and plain films fail to confirm the diagnosis;
• “bird’s beak” is pathognomonic seen on enema contrast study as the contrast comes to a sharp end

Question 11

What are the signs of strangulation?

Answer 11

• Discolored or hemorrhagic mucosa on sigmoidoscopy
• bloody fluid in the rectum
• frank ulceration or necrosis at the point of the twist
• peritoneal signs
• fever
• hypotension
• ↑ WBCs

Question 12

What is the initial treatment?

Answer 12

Nonoperative: If there is no strangulation, sigmoidoscopic reduction is successful in ≈85% of cases; enema study will occasionally reduce (5%)

Question 13

What is the percentage of recurrence after nonoperative reduction of a sigmoid volvulus?

Answer 13

≈40% !

Question 14

What are the indications for surgery?

Answer 14

• Emergently if strangulation is suspected or nonoperative reduction unsuccessful
• (Hartmann’s procedure)
• most patients should undergo resection during same hospitalization of redundant sigmoid after successful nonoperative reduction because of high recurrence rate (40%)