491 COMPARISON OF PROSTATE CONTRACTILITY IN VITRO: AND IN VIVO ASSESSING PROSTATE FUNCTION IN THE MICTURITION CYCLE

Abstract

You have accessJournal of UrologyBladder and Urethra: Anatomy, Physiology and Pharmacology II1 Apr 2012491 COMPARISON OF PROSTATE CONTRACTILITY IN VITRO: AND IN VIVO ASSESSING PROSTATE FUNCTION IN THE MICTURITION CYCLE Yasmin Hocaoglu, Karin Herrmann, Sebastian Walther, Martin Hennenberg, Ricarda Bauer, Christian Gratzke, Christian Stief, and Alexander Roosen Yasmin HocaogluYasmin Hocaoglu Munich, Germany More articles by this author , Karin HerrmannKarin Herrmann Munich, Germany More articles by this author , Sebastian WaltherSebastian Walther Munich, Germany More articles by this author , Martin HennenbergMartin Hennenberg Munich, Germany More articles by this author , Ricarda BauerRicarda Bauer Munich, Germany More articles by this author , Christian GratzkeChristian Gratzke Munich, Germany More articles by this author , Christian StiefChristian Stief Munich, Germany More articles by this author , and Alexander RoosenAlexander Roosen Munich, Germany More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2012.02.561AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Micturition is a complex process that includes anatomic and neurologic interactions for successful voiding. Recently we described on real-time MRI (rtMRI) that vertical contraction of the ventral prostate precedes initiation of male micturition and may contribute to the funnelling of the bladder neck. In this study we aimed to investigate if in vitro contractile strength of the prostate and the prostatic urethra might correlate with the shortening of the ventral prostate seen on rtMRI. METHODS 10 patients undergoing radical prostatectomy (rPx) for prostate cancer were enrolled. Approval was obtained from all patients and by the local ethics committee. Preoperative rtMRI during voiding was performed as described before in 8 patients undergoing rPx, measuring the difference of the cranio-caudal distance of the ventral prostate (VP). To roughly estimate the amount of force required to deform the prostate in a vertical direction as seen on rtMRI, we uniaxially compressed the organ immediately after surgery by the same distance, assuming incompressibility and isotropy of prostatic tissue. A muscle strip (7 x 3 mm) from the ventral prostate, dorsal prostate and prostatic urethra was obtained after pathological evaluation. Contraction was elicited by electrical-field stimulation (EFS: 0.1 ms pulses, 2,4,8,16,32 and 64 Hz for 4s). RESULTS There was a mean cranio-caudal contraction of the VP by 7.6 mm at the onset of micturition on rtMRI (p*=0,002). Mean contractile force of strips elicited by EFS at 32 Hz was 2.899 g for the ventral prostate, 2.035g for the dorsal prostate, and 1.824 g for the prostatic urethra. Extrapolating these values to the whole organ diameter, we calculated comparable force as observed in compression experiments. CONCLUSIONS Our functional and biometric in vitro analyses of prostate tissue demonstrated sufficient contractile strength of the ventral prostate to induce a shortening of the organ as observed on rtMRI. There was significant higher contractile strength in the ventral prostate than in the dorsal prostate or the proximal uretha. The consistency of in vivo and in vitro results underlines the significance of the ventral prostate for the initiation of normal micturition. © 2012 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 187Issue 4SApril 2012Page: e201 Advertisement Copyright & Permissions© 2012 by American Urological Association Education and Research, Inc.MetricsAuthor Information Yasmin Hocaoglu Munich, Germany More articles by this author Karin Herrmann Munich, Germany More articles by this author Sebastian Walther Munich, Germany More articles by this author Martin Hennenberg Munich, Germany More articles by this author Ricarda Bauer Munich, Germany More articles by this author Christian Gratzke Munich, Germany More articles by this author Christian Stief Munich, Germany More articles by this author Alexander Roosen Munich, Germany More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...