SIGNIFICANCE OF RECTAL CONTRACTIONS NOTED ON MULTICHANNEL URODYNAMICS

Independent rectal contractions are frequently noted when performing m ultichannel urodynamics and are often considered to be artifactual. In an effort to determine if this activity is indeed significant, we rev iewed 430 consecutive multichannel urodynamic studies performed on 289 patients. All studies were performed using an analog recorder at 0.5 mm/sec paper speed. Multichannel pressures included total vesical pres sure measured by a urethral catheter, total abdominal pressure measure d by a rectal balloon catheter, subtracted detrusor pressure (vesical minus abdominal), and uroflow measurement when possible. Rectal contra ctions were defined as multiple fluctuations in abdominal pressure as measured by the rectal balloon catheter which were independent of chan ges in total vesical pressure. These fluctuations could not be reprodu ced by abdominal stressing or Kegel-type maneuvers. Contractions were noted to be of high or low amplitude, continuous or intermittent. Of t he 289 patients, 109 (38%) had a study positive for rectal contraction s. Similarly, 168 of 430 studies (38%) were positive. In patients with neurologic disease, rectal contractions were noted in 61/120 (51%). I n patients with no history of neurologic disease, 48/169 (29%) had rec tal contractions (P < 0.001). Furthermore, when patients without a his tory of neurologic disease were evaluated with respect to the presence of detrusor instability, a positive study was noted in 27/67 (40%) wi th instability but in only 21/102 (21%) of patients without instabilit y (P = 0.005). Rectal contractions also occurred with a higher frequen cy in patients with bladder hyperactivity of any etiology. To further support that rectal contractions were not a randomly occurring event, a subgroup of 86 patients who had undergone multiple studies was analy zed. Studies were consistently positive or negative for rectal contrac tions in 86% of patients. Rectal contractions noted on multichannel ur odynamics appear to be neither artifactual nor randomly occurring even ts. The association with neurologic disease and detrusor hyperactivity is interesting and may indicate underlying pelvic floor dysfunction. (C) 1995 Wiley-Liss, Inc.