HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Wai, C. Y. Articles by Word, R. A. PubMed PubMed Citation Articles by Wai, C. Y. Articles by Word, R. A.

Recovery of External Anal Sphincter Contractile Function After Prolonged Vaginal Distention or Sphincter Transection in an Animal Model

From the Divisions of ¹Female Pelvic Medicine and Reconstructive Surgery and ²Reproductive Endocrinology, Department of Obstetrics and Gynecology, University of Texas Southwestern Medical Center, Dallas, Texas.

OBJECTIVE: To estimate the effect of prolonged vaginal distention and anal sphincter transection on contractile properties of the external anal sphincter as a function of time.

METHODS: One hundred thirty-nine young female virginal rats were randomly assigned into four treatment groups (sham, vaginal distention, transection of anal sphincter plus repair, or combined distention and transection plus repair). After 3 days, 3 months, or 6 months, the anal sphincter complex was analyzed for peak force of twitch tension, peak tetanic force, fatigue, and maximal responses to electrical field stimulation. Statistical analysis was performed using analysis of variance (Student-Neuman-Keuls).

RESULTS: After 3 days, vaginal balloon distention, anal sphincter transection with repair, and combined distention and transection plus repair resulted in compromise of maximal tetanic contraction and electrical field stimulated force generation. Twitch tension, and resistance to fatigue were also significantly decreased in animals with anal sphincter disruption and repair with and without vaginal distention at 3 days. Contractile function of the external anal sphincter, however, was fully recovered by 3 months and was sustained at 6 months in all treatment groups. The time course of repair was slower in animals with sphincter laceration.

CONCLUSION: Anal sphincter transection with or without antecedent prolonged vaginal distention results in severe compromise of external anal sphincter function in the immediate period after injury. In this animal model, complete recovery of external anal sphincter function occurs 3 months after initial insult.