Water-perfused manometry vs three-dimensional high-resolution manometry: a comparative study on a large patient...

Our aim was to compare for the first time measurements obtained with water-perfused catheter anorectal manometry and three-dimensional (3D) high-resolution manometry in patients with anorectal disorders.

Consecutive patients referred to our centre for anorectal manometry (ARM) were recruited to undergo the two procedures successively. Conventional manometry was carried out using a water-perfused catheter (WPAM) and high-resolution manometry was achieved with a 3D probe (3DHRAM). For each procedure, parameters recorded included the following: anal canal length, resting pressure, squeeze pressure and rectal sensitivity.

Two hundred and one patients were included in this study. The mean values for resting and squeeze pressures were correlated and found to be significantly higher when measured with 3DHRAM than with WPAM. However, the length of the anal canal was not significantly different when measured by the two techniques without correlation between the two mean values obtained. The presence of the rectoanal inhibitory reflex was systematically assessed by both WPAM and 3DHRAM and anismus was also systematically diagnosed by both WPAM and 3DHRAM.

The pressure values obtained with 3DHRAM are correlated with those measured with conventional manometry but are systematically higher. 3DHRAM has the advantage of providing a pressure recording over the entire length and circumference of the anal canal, allowing a more useful physiological assessment of anorectal function.