The role of the anatomy of the sigmoid colon in developing sigmoid volvulus: a cross-sectional study.

Purpose: The aim of this study was to determine the length of the sigmoid colon and sigmoid mesocolon in living subjects and fresh cadavers.

Methods: The subjects for the study were consecutive 50 living subjects undergoing abdominal surgeries via midline incision and 50 fresh cadavers undergoing a medicolegal postmortem at Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Osun State, Nigeria.

Results: The study showed that the mean length of the sigmoid colon in living subjects was 48.9 ± 1.3 cm (range 30.5-65 cm) while the mean length of the sigmoid colon in cadaver subjects was 50.1 ± 1.6 cm (range 34.5-67.8 cm) and this was not statistically significantly different. Two patterns of the shape of the sigmoid loop were identified: dolichomesocolic and brachymesocolic pattern. In about 80 % of subjects in both groups, dolichomesocolic-type was seen. The gender analysis showed that males had statistically significant longer sigmoid colon (P = 0.040). The dimension of sigmoid colon significantly increased with age of the patients in cadaver subjects and in both sexes (P = 0.001).

Conclusions: The study concluded that the lengths of sigmoid colon are not different in living and cadaver subjects but are relatively longer than measurement from western countries. The lengths of sigmoid colon and mesocolon also increases with age and this may possibly be the anatomical basis for the frequent occurrence of sigmoid volvulus and failed colonoscopy among the older population in our environment.