Length tension function of puborectalis muscle: implications for the treatment of fecal incontinence and pelvic floor disorders.

Background/aims: External anal sphincter (EAS) and puborectalis muscle (PRM) play important role in anal continence function. Based on length-tension measurement, we recently reported that the human EAS muscle operates at short sarcomere length under phys-iological conditions. Goal of our study was to determine if PRM also operates at the short sarcomere length.

Vaginal high-pressure zone assessed by dynamic 3-dimensional ultrasound images of the pelvic floor.

Objective: The purpose of this study was to determine the shape and characteristics of the vaginal high-pressure zone (HPZ) by imaging a compliant fluid-filled bag that had been placed in the vaginal HPZ with the 3-dimensional ultrasound system.

Study Design: Nine nulliparous asymptomatic women underwent 3-dimensional ultrasound imaging and vaginal pressure measurements. A compliant bag was placed in the vagina and filled with various volumes of water.

Prevalence of increased esophageal muscle thickness in patients with esophageal symptoms.

Background: Patients with achalasia, diffuse esophageal spasm (DES), and nutcracker esophagus have a thicker muscularis propria than normal subjects. The goal of our study was to determine the prevalence of increased muscle thickness in a group of unselected patients referred to the esophageal function laboratory for evaluation of the symptoms.

Methods: We studied 40 normal subjects and 94 consecutive patients.

Effects of pelvic floor muscle contraction on anal canal pressure.

The role of pelvic floor muscle contraction in the genesis of anal canal pressure is not clear. Recent studies have suggested that vaginal distension increases pelvic floor muscle contraction. We studied the effects of vaginal distension on anal canal pressure in 15 nullipara asymptomatic women.

Synchrony between circular and longitudinal muscle contractions during peristalsis in normal subjects.

The current understanding is that longitudinal muscle contraction begins before and outlasts circular muscle contraction during esophageal peristalsis in normal subjects. The goal of our study was to reassess the relationship between the contractility of two muscle layers using novel ways to look at the muscle contraction. We studied normal subjects using synchronized high-frequency ultrasound imaging and manometry.