Discrepancies in anal manometric pressure measurement--important or inconsequential?
OBJECTIVE
Maximum resting and squeeze pressures have been the most widely employed parameters for manometric assessment of the anal sphincters. However, a single maximum value may not always be the best assessment.


METHODS
The aim of this study was to compare mean and maximum resting and mean and maximum squeeze pressures in a large sample population. All manometric pressure profiles were reviewed by a single individual blinded to the patient's age and diagnosis.


RESULTS
Four hundred sixty-six patients with a measurable high-pressure zone were included in this study. The study population was comprised of 279 females and 186 males. A significant difference was found between mean (56.26 mmHg) and maximum (79.2 mmHg) resting pressures (P < 0.01) and also between mean (81.25 mmHg) and maximum (119.50 mmHg) squeeze pressures (P < 0.01). A significant difference (P < 0.01) was also observed when compared by length of the high-pressure zone.


CONCLUSIONS
The measurement, documentation, and reporting of mean resting and mean squeeze pressures provide a better perspective of anal manometric results, since the two sets of values are significantly different (P < 0.01), regardless of the anal canal length. Therefore, these data support the standardized evaluation of both mean and maximum pressures in individual patients and in published series.
Morgado
P J
PJ
Department of Colorectal Surgery, Cleveland Clinic Florida, Fort Lauderdale 33309.
Wexner
S D
SD
Jorge
J M
JM
D001003:Anal Canal / Q000502:physiology*; D000704:Analysis of Variance; D005260:Female; D006801:Humans; D008297:Male; D008365:Manometry / Q000592:standards / Q000706:statistics & numerical data; D008875:Middle Aged; D011312:Pressure