Colonic Volvulus
Richard M. Devine, M.D., F.A.C.S.
Assistant Professor of Surgery
Mayo Clinic
Rochester, Minnesota
Incidence and Etiology
Colonic volvulus is a twisting of a portion of the colon around its mesentery creating a colonic obstruction. The sigmoid colon and cecum are the most common portions of the colon involved.
The incidence of colonic volvulus varies in different parts of the world. In the United States and Great Britain volvulus accounts for approximately 1% to 7% of all cases of large bowel obstruction.(1) In some west African states volvulus is responsible for 20% to 50% of intestinal obstructions.(2) In a population based study in Olmsted County Minnesota the incidence of colonic volvulus was approximately 3 cases per year per 100,000 persons. There was a marked difference in incidence between those over 60 years old and those younger than 60. Those under 60 had an incidence of only 1 per year per 100,000 persons while those over 60 had an incidence of 14/year/100,000(3). In the United States the incidence of sigmoid volvulus is slightly more common than cecal volvulus with a ratio of about 60 to 40. The mean age of patients with cecal volvulus is about 10 years younger than the mean age of patients with sigmoid volvulus. In the United States the mean age of patients with sigmoid volvulus is 62. Transverse colon and splenic flexure volvulus occurs but they represent only less than 5% of cases in the United States.
Sigmoid volvulus occurs in people with long, redundant sigmoid colons with a narrow mesentery. Cecal volvulus occurs in people whose right colon has failed to fuse to the retroperitoneum, creating an intraperitoneal ascending colon that can twist around the axis of the ileocolic artery. It is unknown how much of these anatomical prerequisites are congenital abnormalities or acquired changes. Congenital factors probably play a bigger role in cecal volvulus while acquired changes are a larger factor in sigmoid volvulus. Evidence that sigmoid volvulus is due to acquired changes is that sigmoid volvulus rarely occurs in young patients, has a higher incidence in certain regions of the world, and has a higher incidence in patient population that are predisposed to megacolon. The high incidence of volvulus in Africa is thought to be due to a high residue diet which results in a redundant colon. Patients who are institutionalized long term for psychiatric problems are also over represented in reported series(4). The prevalence of chronic constipation in these patients creates a redundant colon, predisposing them to sigmoid volvulus. In Brazil, Chagas' disease, with its associated megacolon, is a major cause of colonic volvulus.
Transverse colon volvulus is associated with both developmental abnormalities, such as a freely mobile right colon, and associated conditions such as chronic constipation, distal obstructions, and autonomic dysfunction.
In pregnant women sigmoid volvulus is the most common cause of intestinal obstruction. In a combined series of patients from 10 reports 44% of pregnant patients with bowel obstruction had a sigmoid volvulus.
Diagnosis
Patients with colonic volvulus present with abdominal pain and distention. The abdominal distention is often very marked, greater than usually seen in a small bowel obstruction or colonic obstruction due to malignancy. Some patients may present with signs of shock due to dehydration, bowel ischemia, or peritonitis.
Abdominal plain films will show large, massively dilated loops of bowel. The diagnosis of volvulus, however, is often not made by plain abdominal X-rays. In one series the diagnosis of cecal volvulus was made in only 25% of patients based on plain films alone. The most common misdiagnosis was sigmoid volvulus. In sigmoid volvulus the correct diagnosis was made in 62% of patients based on plain films alone.(4) In sigmoid volvulus the classic plain film appearance is a dilated "bent inner-tube" with the axis of the bend running from the right upper quadrant into the pelvis.
In cecal volvulus the dilated cecum is "comma-shaped" or bean-shaped. This large comma may be located anywhere in the abdomen but is most frequent in central to left side of the abdomen. About 50% of cases have dilated loops of small bowel seen in association with the dilated cecum. The dilated small bowel is to the right of the dilated cecum.
The use of a contrast enema to confirm the diagnosis is debatable. In those cases in which the diagnosis is clear on a plain film a contrast exam is not needed to confirm the diagnosis. If the diagnosis is not clear, however, an expedient contrast exam can be extremely helpful and should not result in undo delay of surgical or endoscopic treatment. In sigmoid volvulus the classic finding on contrast exam is a "bird beak" or "ace of spades" deformity seen at the site of the colonic twist. Contrast studies in cecal volvulus show a tapered obstruction in the ascending colon. In difficult cases contrast studies can differentiate volvulus from pseudo-obstruction or obstruction due to a cancer.
Occasionally patients with abdominal distention and pain who have nonspecific dilated loops of bowel on plain radiographs will be referred for CT scan. In addition to dilated loops of bowel, a round, soft tissue mass with a whirled configuration, similar to an image of a hurricane on a weather map will be seen at the site of torsion. This has been seen in midgut, cecal and sigmoid volvulus(5) and is referred to as the "whirl" sign.
Treatment
Sigmoid Volvulus
In those patient who are stable and without signs or symptoms of bowel ischemia or perforation , endoscopic decompression is the procedure of choice. When successful through the rigid proctoscope, there is usually a sudden and dramatic release of air and fecal matter. It's best to change into a scrub suit before attempting this procedure. If decompression with a rigid scope is unsuccessful, then an attempt with a flexible endoscope is warranted. Friedman, et al, had three patient in their series in which the point of torsion was beyond the reach of the rigid scope. All three of these patients were successfully decompressed with a flexible sigmoidoscope(6). Endoscopic decompression has been reported to successfully decompress the colon in 70 to 90% of cases(6.7.8). After endoscopic decompression placement of a rectal tube is recommended.
If endoscopic decompression is unsuccessful, the patient should have immediate surgery. If the bowel wall is ischemic, a resection with colostomy must be done. If the colon is viable, the surgeon has several choices. Operative reduction with placement of rectal tube, followed by elective surgery two to three weeks later is one option. Primary resection with either a colostomy or primary anastomosis is another option. I would favor a primary anastomosis only in those patients who are stable and could tolerate an intraoperative bowel prep.
The recurrence rate after endoscopic decompression is high. In a combined series of 149 patients who did not have surgery after successful endoscopic decompression, the recurrence rate was 43% with a 10% mortality in these patients(9). Because of this high recurrence rate, surgery with sigmoid resection during the same hospitalization is recommended. There is some controversy in elderly patients, but in general maximal survival is achieved by early elective resection(8). Sigmoid resection is usually easy and straight forward and can be done through a lower midline incision. The procedure can also be accomplished with a laparoscopic-assisted approach. Other novel procedures reported but I don't recommend include laparoscopic fixation of the redundant loop(10) and fixation of the sigmoid loop using a percutaneous and endoscopically placed sigmoidostomy tube (using the same technique used to place a PEG - percutaneous endoscopic gastrostomy) (11).
Cecal Volvulus
Although there are reports of decompression of cecal volvulus using a colonoscope, its failure rate is high and it's not generally recommended. One reason for not doing endoscopic decompression is the presence of gangrenous bowel in 20 to 25% of cases. Five surgical procedures have been used in the treatment of cecal volvulus: detorsion alone, cecopexy, cecostomy, both cecopexy and cecostomy, and resection. In a combined series from 15 reports, the recurrence rate for detorsion alone was 13%, the same recurrence rate as for cecopexy(12). Cecostomy had a recurrence rate of 1%, but there was also a high incidence of wound infection in cecostomy. Persistent fecal fistula is another risk of cecostomy. Resection eliminates the risk of recurrence entirely. In the absence of any randomized study, one procedure cannot be recommended over another. I would favor a resection in a stable patient, but I can understand the temptation to simply do a cecopexy and get out if it is 2 o'clock in the morning or the patient is frail. O'Mara, et al, followed 18 patients who had cecopexy and there was no recurrence after a mean follow-up that averaged 4.8 years(13). Resection is of course mandatory it there is any evidence of bowel wall compromise. Mortality rates in the range of 10 to 20% are reported due to delay in diagnosis and treatment and comorbidity in the patient group.
Transverse Colon Volvulus
The treatment of transverse colon volvulus is similar to that of cecal volvulus. Approximately 16% of cases have been associated with gangrene, so although successful decompression with a colonoscope has been reported, the surgeon should be aware bowel wall ischemia may be present. Surgical procedures involve either fixation or resection(14) .
References
1. Jones-Ian T, Fazio VS. Colonic volvulus, etiology and management. Dig Disease 1989; 7:203-209.
2. Bagarani M, et al. Sigmoid volvulus in west africa: A prospective study on surgical treatments. Dis Colon & Rectum 1993; 36:186-190.
3. Ballantyne GH, et al. Volvulus of the colon, incidence of mortality. Ann Surg 19856; 202:83-92.
4. Hiltonen KM, et al. Colonic volvulus. Diagnosis and results of treatment in 82 patients. Eur J Surg 1992; 158-607-611.
5. Frank AJ, et al. Cecal volvulus: The CT whirl sign. Abdominal Imaging 1993; 18-288-289.
6. Friedman JD, Odland M.D., Bobrick MP. Experience with colonic volvulus. Dis Colon & Rectum 1989; 32:409-416.
7. Peoples JD, McCafferty JC, Scher KS. Operative therapy for sigmoid volvulus. Dis Colon & Rectum 1990; 33:643-646.
8. Bak MP, Boley SJ. Sigmoid volvulus in elderly patients. Am J of Surg 1986; 151:71-75.
9. Ballantyne GH. Review of sigmoid volvulus. History and results of treatment. Dis Colon & Rectum 1982; 25:494-501.
10. Miller R, et al. Laparoscopic fixation of sigmoid volvulus. Br J Surg 1992; 79-435.
11. Chiulli RA, Swantkowski TM. Sigmoid volvulus treated with endoscopic sigmoidopexy. Gast Endoscopy 1993; 39:194-196.
12. Tejler G, Jiborn H. Volvulus of the cecum. Report of 26 cases and review of the literature. Dis Colon & Rectum 1988; 31:445-449.
13. O'Mara CS, et al. Cecal volvulus. Analysis of 50 patients with long-term follow-up. Ann Surg 1979; 189:724-731.
14. Van Gilder JG, Randall MA, Metcalf AM. Transverse colon volvulus: case reports and literature review. Contemporary Surgery 1997; 51:239-243.