Joel Garland Fletcher MD, Presenter: Grant, Siemens, AG Grant, Genentech, Inc Grant, Johnson & Johnson Consultant, Abbott Laboratories

Adil Bharucha MBBS,MD, Abstract Co-Author: Nothing to Disclose

Jeff L. Fidler MD, Abstract Co-Author: Consultant, Abbott Laboratories

David Maitland Hough MD, Abstract Co-Author: Nothing to Disclose

Puborectalis tear, atrophy, and impaired or disordered function are associated with defecatory disorders. However, little is known about appearance of the puborectalis (PR) in normal women, or about the location of the PR along the length of the anal canal. Our purpose is to describe the appearance and location of the PR in asymptomatic women.

69 asymptomatic females without defecatory disorders underwent endoanal MR imaging followed by dynamic MR proctography as part of a research study. Endoanal imaging was performed using fast spin-echo T2-weighted imaging in 3 planes (3.5 mm slice thickness, 12 cm FOV). A GI radiologist evaluated for PR tear/atrophy, as well as total length of the anal sphincters. Using coronal images, the distance between the superior edge of the PR and the levator plate was recorded, along with cradiocaudal length of the anal canal and PR, and compared to obstetric history and findings at MR proctography.

60/69 (87%) asymptomatic subjects had normal PR appearance bilaterally while 9/69 (13%) has unilateral/bilateral atrophy or tear. Mean length of anal canal was 6.4 cm, with the mean craniocaudal length of the puborectalis being 2.1 +/- 0.6 cm. The superior aspect of the PR was within 1 cm of the levator plate in only 25/69 (36%), but in 12/69 (17%) subjects, it was located > 3 cm from the levator plate, with the mean distance being 1.7 +/- 1.0 cm. In 20 (29%) and 29 (42%) subjects, the superior edge of the puborectalis was located > 30% of the length of the anal canal from the levator plate (for the left and right PR, respectively). Increased distance between the levator plate and PR tended to be associated with vaginal hysterectomy (29% vs. 23%) and patulous anal canal (35% vs. 24%), but not with abdominal hysterectomy, age, or anorectal angle.

A minority of asymptomatic female subjects have imaging evidence of PR injury. However, there is great variability in the location of the PR along the craniocaudal length of the anal canal. The clinical significance of this variability is unknown, but may play a role in patients with defecatory disorders.

About 10% of asymptomatic female subjects have imaging evidence of puborectalis injury, and there is great variability in the location of the muscle along the length of the anal canal.

Fletcher, J, Bharucha, A, Fidler, J, Hough, D, Variability in Puborectalis Appearance and Location In Asymptomatic Women.  Radiological Society of North America 2011 Scientific Assembly and Annual Meeting, November 26 - December 2, 2011 ,Chicago IL. http://archive.rsna.org/2011/11034589.html