Volvulus

Overview of Volvulus

A volvulus is a twisting, or torsion, of a segment of the intestine around its own mesentery (the tissue that holds the intestines in place). This twisting can cause a complete bowel obstruction, preventing the passage of stool and gas. More critically, the torsion can cut off the blood supply to the involved segment of bowel, leading to ischemia, gangrene, and perforation. Volvulus most commonly affects the sigmoid colon (approximately 60% of cases) and the cecum (approximately 40% of cases), as these are the most mobile parts of the large intestine. Volvulus of the transverse colon or splenic flexure is rare. A volvulus is a surgical emergency that requires prompt diagnosis and treatment to avoid life-threatening complications.

The symptoms of a volvulus are often sudden and severe, reflecting an acute bowel obstruction. Common signs include:

• Abdominal Pain: Typically cramping and severe, which may become constant if ischemia develops.
• Abdominal Distension: The abdomen can become massively swollen and tympanitic (drum-like) to percussion.
• Nausea and Vomiting: This is more common with cecal volvulus due to the more proximal obstruction.
• Obstipation: An inability to pass stool or gas.

Causes and Risk Factors

A volvulus can only occur in a segment of the colon that is mobile and redundant, with a narrow point of fixation. Several factors increase the risk of developing a volvulus:

• Sigmoid Volvulus: Risk factors include a long, redundant sigmoid colon with a narrow mesenteric base, chronic constipation, a high-fiber diet, and older age. It is more common in institutionalized patients and those with neuropsychiatric conditions.
• Cecal Volvulus: This is often due to a congenital anomaly where the cecum and ascending colon are not properly fixed to the retroperitoneum, making them abnormally mobile. Prior abdominal surgery and pregnancy are also risk factors. Cecal volvulus typically affects a younger patient population compared to sigmoid volvulus.

Diagnosis and Tests

The diagnosis of a volvulus is typically made with imaging studies in the emergency setting.

• Abdominal X-ray: A plain abdominal radiograph may show the classic signs of a volvulus, including a massively dilated loop of colon, often described as a 'coffee bean' or 'bent inner tube' sign.
• Computed Tomography (CT) Scan: A CT scan of the abdomen and pelvis is the most accurate diagnostic test. It can confirm the volvulus, identify the site of torsion by showing a 'whirl' or 'swirl' sign of the twisted mesentery and vessels, and assess for signs of complications such as ischemia or perforation.
• Contrast Enema: A water-soluble contrast enema can show a 'bird's beak' tapering at the point of the twist in a sigmoid volvulus but is less commonly used now that CT scans are readily available.

Treatment depends on the location of the volvulus and whether there are signs of bowel compromise.

Sigmoid Volvulus

• Endoscopic Decompression: In the absence of signs of perforation or peritonitis, the initial treatment for sigmoid volvulus is to attempt to untwist the colon using a flexible or rigid sigmoidoscope. This is successful in 60-95% of cases. A rectal tube is often left in place to help keep the colon decompressed and prevent immediate re-twisting.
• Surgery: After successful endoscopic detorsion, patients are typically recommended to undergo a sigmoid colectomy during the same hospitalization to prevent recurrence, which can be as high as 70%. If there are signs of perforation or ischemia, or if endoscopic detorsion is unsuccessful, emergency surgery is required. This usually involves a sigmoid colectomy. Whether an anastomosis is created or a colostomy is formed (Hartmann's procedure) depends on the patient's stability and the condition of the bowel.

Cecal Volvulus

• Surgery: Cecal volvulus is almost always treated with surgery, as endoscopic detorsion is rarely successful or recommended. The standard operation is a right hemicolectomy with an ileocolic anastomosis. In rare cases in an unstable patient, an ileostomy may be created. Non-resectional procedures like cecopexy (suturing the cecum in place) have a high recurrence rate and are generally not recommended.

Recovery

Recovery after surgery for volvulus depends on the type of operation performed and the overall health of the patient. After elective surgery, patients can expect a hospital stay of several days. Recovery from emergency surgery for a complicated volvulus with perforation is much more prolonged. If a stoma was created, you will receive education from a stoma nurse on how to care for it. Preventing constipation is important, especially after sigmoid volvulus, and can be achieved with a high-fiber diet, adequate fluid intake, and regular exercise.

Can a volvulus happen more than once?
Yes. After a sigmoid volvulus is successfully untwisted with a colonoscope, the recurrence rate is very high, which is why surgery to remove the redundant sigmoid colon is recommended.

What is the difference between a sigmoid and a cecal volvulus?
A sigmoid volvulus is a twist of the S-shaped part of the colon just before the rectum and is more common in the elderly. A cecal volvulus is a twist of the beginning of the colon (cecum) and is more often related to the colon not being fixed in its normal position from birth, affecting a younger population.

Is volvulus hereditary?
No, volvulus itself is not hereditary. However, the anatomical predispositions, such as a redundant colon or a mobile cecum, can have a congenital basis.