Manometric assessment of an artificial bowel sphincter

Background: This study investigated the relationship between functional cli nical results after artificial bowel sphincter implantation and manometric assessment in 12 consecutive patients. Methods: A postoperative manometric study was performed in 12 patients, inc luding measurement of resting and squeeze pressures, opening characteristic s and pressure during straining. The relationship between postoperative fin dings, clinical outcome and preoperative manometric data was investigated. Anal pressure after rectal distension with a closed cuff was studied in sev en patients. Results were expressed as mean(s.d.). Results: Continence for solid stool was achieved in all 12 patients. Five p atients remained incontinent for gas. Anal resting pressure was 108(22)cmH( 2)O; there was no difference between continent and incontinent patients. Re ctal distension induced anal relaxation in six of seven patients. Total dur ation of cuff opening was 113(8) s with an amplitude of 60(22) per cent; re sidual pressure was correlated with the preoperative resting pressure. The total duration of the opening phase in patients with defaecation difficulti es (47(24) (range 0-65)s) was shorter than that in patients without defaeca tion difficulties (178(78) (range 100-320) s) (P = 0.0022). Conclusion: Postoperative defaecation difficulties after implantation of an artificial bowel sphincter are related to a short duration of opening of t he cuff, The anal sphincter played a role in postoperative resting anal pre ssures and allowed relaxation even if the cuff was closed.