Role of Anorectal Physiologic Studies for the Diagnosis and Treatment of Non- relaxing Puborectalis Syndrome

Kim, Nam Hyuk; Hwang, Yong Hee; Choi, Kun Phil

Abstract

PURPOSE: To assess the effectiveness of cinedefecography (CD), anal electromyography (EMG), and anal manometry (ARM) for the diagnosis of non-relaxing puborectalis syndrome (NRPR) and to compare the outcomes for patients after biofeedback therapy (BF).
METHODS
The clinical criteria used in this study for NRPR included straining, incomplete evacuation, tenesmus, and the need for enemas, suppositories, or digitation. Patients who satisfied the clinical criteria were evaluated by use of anorectal physiology tests: CD, EMG, and ARM. The EMG criteria included failure to achieve a significant decrease in the electrical activity of the puborectalis (PR) during attempted evacuation. The ARM criteria included failure to achieve a significant decrease in intra-anal pressure during attempted evacuation. The CD criteria included either paradoxical contraction or failure of the PR to relax together with incomplete evacuation. Other possible etiologies for incomplete evacuation, such as rectal intussusception or rectocele, were excluded in all cases. Fifty-eight constipated patients diagnosed as having NRPR by at least one of anorectal physiolosic tests had more than one BF session. The outcomes for fifty-one patients (mean age, 44.8 years; male-to-female ratio, 22:29) were reported as either improved or unimproved at a mean follow-up of 12.7 (range, 2~30) months. The sensitivities, the specificities, and the positive and negative predictive values for the CD, EMG, and ARM diagnoses of NRPR were calculated to assess the diagnostic accuracy of each test and to identify predictors associated with the outcome of BF.
RESULTS
The sensitivities of EMG, CD, and ARM were 96%, 89%, and 85%, respectively (P>0.05). The positive predictive values of the three tests were 63% for EMG, 52% for ARM, and 51% for CD (P>0.05). The negative predictive values of the three tests were 90% for EMG, 43% for ARM, and 25% for CD (P<0.05). The specificities of the three tests were 38% for EMG, 13% for ARM, and 2% for CD (P<0.05). The positive predictive values the two-study-positive groups and the three-study-positive group were 63% for the EMG- and ARM-positive group, 61% for the CD- and EMG-positive group, 51% for the CD- and ARM-positive group, and 61% for the three-study- positive group (P>0.05).
CONCLUSIONS
A combination of the CD and the EMG tests is suggested for the diagnosis of NRPR.