Update on the pathophysiology of rectal prolapse

The role of rectal redundancy in the pathophysiology of rectal prolapse: a pilot study

Purpose

Rectal prolapse is hypothesized to be caused due to weakness of the pelvic floor which is related to childbearing. However, half of the female patients with rectal prolapse were reported to be nulliparous and this hypothesis doesn't explain the prolapse in males. The aim of this study is to evaluate the role of rectal redundancy in rectal prolapse pathophysiology.

Methods

This study was conducted prospectively. Fourteen patients who underwent rectopexy were included in the study group. A total of 17 patients who underwent laparotomy for another reason and who have no symptoms regarding rectal prolapse were included in the control group. In order to measure the redundancy of the rectum, we have calculated the ratio of length of intraperitoneal rectum (R) to length of distance between promontorium and peritoneal reflection (PRx). The primary outcome of this study was to evaluate whether the R/PRx ratio is higher in patients with rectal prolapse compared to the control group.

Results

Comparing the anatomic features showed that the length of sigmoid colon and length of PRx were not significantly different between the two groups. However, the length of intraperitoneal rectum was significantly higher in the prolapse group. Furthermore, the median R/PRx ratio in the prolapse group was significantly higher than in the control group.

Conclusion

This study showed that intraperitoneal rectum in patients with rectal prolapse is significantly more redundant than in the normal population. This could be considered reasonable evidence for the role of rectal redundancy on rectal prolapse pathophysiology.

An experimental study on the pathophysiology of rectal prolapse

Objective: For decades, rectal prolapse has been hypothesized to be caused due to laxity or weakness of the pelvic floor muscles which is often sup- posed to be related to childbearing in females. However, 50% of females with rectal prolapse have been reported to be nulliparous and this hypothesis does not explain the incidence of rectal prolapse in males. The aim of this study was to evaluate the role of rectal redundancy in rectal prolapse patho- physiology.

Material and Methods: Nineteen female Sprague Dawley rats (250-300 g) at 16 weeks of age were obtained from the animal center. Rats were divided into two groups as rectal mobilization (study) group (n= 9) and sham-operated control (n= 10) group. In the study group, soft dissection was applied and rectum were mobilized up from the pelvic floor to create a redundant or hypermobilized rectum.The primary outcome was the rate of rectal pro- lapse after rectal mobilization.

Results: As compared to the sham-operated control group, in which none of the rats had rectal prolapse throughout the post-surgical period, rectal prolapse was observed in four of the rats in the rectal mobilization group (0% vs. 44%; p= 0.006). Being unable to increase the length of the rectums of the rats, but using only mobilization to create the redundancy, and the lack of data regarding any adhesions after surgery are the main limitations of this study.

Conclusion: This study showed the role of rectal redundancy on the rectal prolapse pathophysiology.