THE PRESSURE-AREA - A VARIABLE FOR THE ASSESSMENT OF ANAL-SPHINCTER FUNCTION

Objective: To assess the contribution of the area under the resting an d squeeze pressure curves, respectively, in the measurement of anal sp hincter function. Design: Open study. Setting: University hospital, Sw eden. Subjects: 106 Healthy volunteers (73 women and 33 men) with no s igns or symptoms of anorectal disease. Interventions: Anorectal manome try with a microtransducer. Outcome measures: Maximal resting and sque eze pressures. Resting and squeeze pressure areas were calculated in t he interval 0-5 cm from the anal verge. Results: There was no differen ce in mean(SD) resting pressure (mmHg) between men (50(17)) and women (47(15)) but there was a significant difference in the mean(SD) restin g pressure area (units) (149(46) compared with 125(46)). The squeeze p ressure was significantly higher in men (193(57)) than in women (115(4 2), t = 7.72, p < 0.001). The difference between the sexes was even mo re pronounced when the squeeze pressure areas were compared: (624(216) and 318(114), respectively, t = 9.50, p < 0.001). Conclusion: Both th e pressure values and the high pressure zone should be considered in t he interpretation of the results of anorectal manometry. The pressure area includes both aspects and showed a greater separation between men and women than the peak pressure value alone.