Incidence and clinical significance of sigmoidoceles as determined by a new classification system

A study was undertaken to assess the incidence and clinical significance of sigmoidocele as a finding during cinedefecography.

All patients who underwent cinedefecography between July 1988 and July 1992 were prospectively evaluated. Clinical data were assessed by a standardized questionnaire. Sigmoidocele was classified based on the degree of descent of the lowest portion of the sigmoid: 1 degree = above the pubococcygeal line; 2 degrees = below the pubococcygeal line and above the ischiococcygeal line; 3 degrees = below the ischiococcygeal line. This classification was then correlated with the patient's symptoms and percentage of redundancy relative to rectal length.

Twenty-four sigmoidoceles (5.2 percent) were noted in 463 cinedefecographic studies; 289 of these patients had constipation. These five males and 19 females were of a mean age of 57 (range, 20-77) years. Nine patients had 1 degree sigmoidocele, seven had 2 degrees, and eight had 3 degrees. Percentage of sigmoid redundancy was 51 percent, 65 percent, and 88 percent for 1 degree, 2 degrees, and 3 degrees, respectively (P = 0.0001). Impaired rectal emptying was present in 16 patients (67 percent). Five of eight patients with 3 degrees sigmoidocele underwent colonic resection with or without rectopexy. The other three patients were conservatively managed. One of seven patients with 2 degrees sigmoidocele underwent colectomy, and the other six were conservatively managed as were all nine patients with 1 degree. Posttreatment improvement was noted in 100 percent (6 of 6) of patients operated on but in only 33 percent (6 of 18) of patients conservatively treated. Thus, this proposed classification system yielded excellent correlation among the mean of level of the sigmoidocele, percentage of redundancy, and clinical symptoms. Furthermore, clinical significance of 3 degrees sigmoidocele is supported by the fact that all five of 3 degrees patients who underwent colonic resection reported symptomatic improvement at a mean follow-up of 23 (range, 15-39) months.

Sigmoidocele may account for symptoms of obstructed defecation, and, therefore, it must be considered in the differential diagnosis and evaluation of constipation. Staging of sigmoidocele is useful in determining both clinical significance and optimal treatment.