533 Is the striated urethral sphincter at risk by standard suture ligation of the dorsal vein complex in radical prostatectomy? An anatomical study in adult human male cadavers

533

Is the striated urethral sphincter at risk by standard suture ligation of the dorsal vein complex in radical prostatectomy? An anatomical study in adult human male cadavers Eur Urol Suppl 2014;13;e533          

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Ganzer R.1 , Stolzenburg J-U.1 , Weber F.2 , Burger M. 3 , Bründl J. 3 1 University 3 University

of Leipzig, Dept. of Urology, Leipzig, Germany, 2 University of Regensburg, Dept. of Pathology, Regensburg, Germany, of Regensburg, Dept. of Urology, Regensburg, Germany

INTRODUCTION & OBJECTIVES: Despite ongoing technical refinements urinary incontinence can be a consequence of radical prostatectomy. One important point in it’s etiology is impairment of the striated urethral sphincter (SS). Suture ligation of the dorsal vein complex (DVC) before it’s transection is widely accepted in radical prostatectomy in order to get bloodless access to the apex of the prostate and the membranous urethra. It has been argued, that standard suture ligation of the DVC might affect the integrity of the underlying SS. Some authors have shown significant improvements in postoperative continence rates by primary cold incision of the DVC followed by selective suture ligation compared to the standard suture ligation technique (“cut & ligate” versus “ligate & cut”). Our intention was an anatomical study of the topography of the SS and the adjacent veins of the DVC in order to investigate if standard suture ligation of the DVC might harm the SS. MATERIAL & METHODS: Specimens were obtained from adult male autopsy cadavers. The study was approved by the local ethical committee. Following a standardized autopsy protocol the urogenital organs were removed en bloc starting with a sharp dissection off the pubic bone. Serial transverse wholemount sections were created with an interval of 1 mm and stained with hematoxyline-eosin (HE). From all specimens one section was investigated from the level of the prostatic apex and one 5 mm distal to the apex. Image J software (Wayne Rasband, National Institute of Health, USA) was used to measure the number and total surface area of the veins of the DVC and the surface area of the SS. Two transverse lines were drawn: one marking the lower boundary of the DVC and one marking the anterior border of the SS. We then calculated the percentage of surface area of the SS that would be entrapped by a ligation stich that includes all veins of the DVC. RESULTS: Specimens of five adult male cadavers were available for analysis. A mean of 12.5 ± 3.8 and 12.0 ± 3.5 veins with a mean total surface area of 13.3 ± 4.6 mm2 and 11.7 ± 6.9 mm2 were counted at the level of the apex and 5 mm distal to the apex, respectively. The mean surface area of the SS was 116.1 ± 80.7 mm2 and 80.9 ± 63.6 mm2 , respectively. The mean surface area of the SS above the lower border of the DVC was 42.5 ± 41.4 mm2 (36.6%, range 16.4%-55.4%) and 28.4 ± 20.7 mm2 (35.1%, range 22.6%-62.7%) at the apex and 5 mm distal to the apex, respectively. CONCLUSIONS: A considerable percentage of the surface area of the SS is located above the lower level of the DVC at the apex and 5 mm distal to the apex. These are typical locations to ligate the DVC. Our findings suggest that a standard suture ligation technique of the DVC is associated with a high risk to affect sphincter tissue. Our study is in accordance with recent clinical studies showing improved early postoperative continence rates by transection of the DVC followed by selective suture ligation.