Manometric assessment of an artificial bowel sphincter

This study investigated the relationship between functional clinical results after artificial bowel sphincter implantation and manometric assessment in 12 consecutive patients.

A postoperative manometric study was performed in 12 patients, including measurement of resting and squeeze pressures, opening characteristics and pressure during straining. The relationship between postoperative findings, clinical outcome and preoperative manometric data was investigated. Anal pressure after rectal distension with a closed cuff was studied in seven patients. Results were expressed as mean(s.d.).

Continence for solid stool was achieved in all 12 patients. Five patients remained incontinent for gas. Anal resting pressure was 108(22) cmH2O; there was no difference between continent and incontinent patients. Rectal distension induced anal relaxation in six of seven patients. Total duration of cuff opening was 113(8) s with an amplitude of 60(22) per cent; residual pressure was correlated with the preoperative resting pressure. The total duration of the opening phase in patients with defaecation difficulties (47(24) (range 0-65) s) was shorter than that in patients without defaecation difficulties (178(78) (range 100-320) s) (P = 0.0022).

Postoperative defaecation difficulties after implantation of an artificial bowel sphincter are related to a short duration of opening of the cuff. The anal sphincter played a role in postoperative resting anal pressures and allowed relaxation even if the cuff was closed.