Definition and Overview

Sigmoid volvulus refers to the twisting of the sigmoid colon, the segment of the colon closest to the rectum and anus. It is associated with old age and long-standing chronic constipation that weakens the colon’s muscular wall.

The condition is very rare in the United States as well as other developed countries. However, it remains to be the leading cause of acute bowel obstruction in Asia, Africa, South America, and Eastern Europe, accounting for up to 80% of cases. It commonly occurs in older, debilitated adults with underlying psychiatric or neurologic disease. It is extremely rare in infants and children.

Sigmoid volvulus can be treated by untwisting and decompressing the sigmoid colon. However, an elective surgery that involves resecting the redundant sigmoid colon is generally preferred because it prevents recurrences.

Causes of Condition

The most common causes of sigmoid volvulus are:

  • Chronic constipation

  • Prolonged or excessive use of laxatives

  • Chagas disease - An inflammatory and infectious disease caused by a parasite called Trypanosoma cruzi. It is common in South America, Mexico, and Central America.

  • An enlarged colon (megacolon)

  • Hirschsprung disease, which causes intestinal obstruction and severe constipation

  • Abdominal adhesions, which refer to bands of scar tissue that form following an abdominal injury, surgery or infection

  • A diet that is too high in fiber

  • Anatomic problems, such as:

1.) A birth defect known as intestinal malrotation

2.) A narrow mesentery connection at the based of the sigmoid colon

3.) A movable or elongated sigmoid colon that is not attached to the abdominal wall

Key Symptoms

Sigmoid volvulus often results in intestinal obstruction, which prevents food, gastric acids, fluids, and gas from flowing normally through the digestive tract. It also cuts the blood supply to a segment of the colon. This results in the following symptoms:

  • Abdominal bloating

  • Abdominal pain

  • Bloody stool

  • Constipation

  • High fever

  • Episodes of mild attacks that resolve by passing large quantities of stool or gas

  • Ischemic bowel

  • Peritonitis, or the inflammation of tissue that lines the inner wall of the abdomen

  • Vomiting

Who to See and Types of Treatments Available

Patients showing signs and symptoms of sigmoid volvulus must seek medical attention to obtain diagnosis and treatment as soon as possible. They can be initially seen by a general practitioner (GP), family doctor, or paediatrician (if the patient is a child or adolescent). If they are suspected of suffering from sigmoid volvulus, they are referred to a gastroenterologist, a specialist in diseases of the digestive system or gastrointestinal tract.

The condition is diagnosed through the review of the patient’s medical history and by using various imaging tests to obtain detailed images of the internal organs. These tests are used to detect any changes and abnormalities in the large intestine and confirm the presence of sigmoid volvulus:

  • Abdominal x-ray

  • Computed tomography (CT) scan

  • Magnetic resonance imaging (MRI)

  • Ultrasonography

  • Sigmoidoscopy - A test to view the lower 20 inches of the sigmoid colon and rectum. It uses a pencil-thin tube (sigmoidoscope) with an attached light and camera on its end. The sigmoidoscope is inserted into the anus and threaded through the lower part of the colon. The doctor then views the inside of the colon through a video monitor.

If volvulus is found during sigmoidoscopy, the sigmoid colon will be untwisted and decompressed during the same procedure with the use of flatus tubes. This method is highly effective in relieving obstruction and other sigmoid volvulus symptoms. However, it does not guarantee against recurrences. In fact, as many as 60% of patients develop the condition more than once after the procedure.

For this reason, most surgeons recommend surgery following the untwisting and decompression of the colon. The surgical approach with the lowest recurrence rate is sigmoid colectomy with primary anastomosis. The procedure, which removes the sigmoid colon, can be performed either through traditional open surgery or laparoscopically. The latter is preferred by most surgeons and patients because it is minimally invasive. It uses smaller incisions rather than a long cut in the abdomen. Thus, it minimises recovery time as well as the common risks of surgery, such as infection, scarring, and pain.

For the procedure, the surgeon will remove the sigmoid colon as well as the blood vessels and lymph nodes connected to it. The remaining side of the colon is then attached to the top of the rectum (anastomosis) using either sutures or staples.

Just like with other abdominal operations, sigmoid colectomy has risks and possible complications. In order to minimise the risks, patients undergo a thorough pre-operative assessment to ensure that they are fit enough for surgery. However, some still suffer from the following:

  • Bleeding

  • Wound infections

  • Anastomotic leak

  • Delayed healing - Sometimes, the bowel may take longer than expected to start working. In such cases, a period of bowel rest and continued intravenous fluids are recommended.

  • Abdominal distension

  • Vomiting

  • Abdominal pain

  • Conversion - There are some cases where the surgeon starts the procedure using the minimally invasive technique but is forced to make a cut when complications or unforeseen events develop. This can prolong surgery time.

References:

  • DRAPANAS T, STEWART JD. Acute sigmoid volvulus. Concepts in surgical treatment. Am J Surg. 1961 Jan. 101:70-7. [Medline].

  • Hendrick Jw. Treatment Of Volvulus Of The Cecum And Right Colon. A Report Of Six Acute And Thirteen Recurrent Cases. Arch Surg. 1964 Mar. 88:364-73. [Medline].

  • Vaez-Zadeh K, Dutz W, Nowrooz-Zadeh M. Volvulus of the small intestine in adults: a study of predisposing factors. Ann Surg. 1969 Feb. 169(2):265-71.

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