Reconstructive urology

Stenz, Arnulf

doi:10.1590/S1677-55382004000400020

UROLOGICAL SURVEY

Reconstructive urology

Current and future strategies for preventing and managing erectile dysfunction following radical prostatectomy

Montorsi F, Briganti A, Salonia A, Rigatti P, Burnett AL

Department of Urology, Università Vita-Salute San Raffaele, Via Olgettina 60, 20132, Milan, Italy, and Department of Urology, The Johns Hopkins Hospital, Baltimore, Maryland, USA

Eur Urol. 2004; 45: 123-133

INTRODUCTION AND OBJECTIVES: As radical prostatectomy remains a commonly used procedure in the treatment of clinically localized prostate cancer, we critically analyzed current and future strategies for preventing and managing postoperative erectile dysfunction.

METHODS: Systematic literature review using Medline and CancerLit from January 1997 to June 2003. Abstracts published in the journals European Urology, The Journal of Urology and the International Journal of Impotence Research as official proceedings of internationally known scientific societies held in the same time period were also assessed.

RESULTS: Patient selection and surgical technique are the major determinants of postoperative erectile function. Apoptosis of corporeal smooth muscle cells plays a role in the development of cavernous veno-occlusive dysfunction following radical prostatectomy. Pharmacological prophylaxis and treatment of postoperative erectile dysfunction is effective and safe. The concepts of cavernous nerve reconstruction and neuroprotection have been associated to promising results.

CONCLUSIONS: In the hands of experienced surgeons, properly selected patients undergoing a nerve sparing radical prostatectomy should achieve unassisted or medically assisted erections postoperatively.

Editorial Comment

This paper written by a team of young experts on the treatment of sexual dysfunction nicely describes how erectile function can currently be treated after oncological pelvic surgery. It is a valuable reference for both the pelvic surgeons performing potency preserving techniques and those who deal with these patients postoperatively. Nerve preservation is currently the only clinically truly proven method of preserving potency after radical prostatectomy or cystoprostatectomy. Although there are data that have shown the results of autologous nerve interposition if autonomic periprostatic nerves cannot be preserved, the true value and applicability needs to be reproduced in larger patient cohorts. Another interesting future aspect may be the use of neurogenesis inducing drugs or pharmatherapeutically protective substances such as immunophilin ligands, which are currently under clinical investigation.

Dr. Arnulf Stenzl

Professor and Chairman of Urology

Eberhard-Karls-University Tuebingen

Tuebingen, Germany

Neuroanatomy of the human female lower urogenital tract

Yucel S, De Souza A Jr, Baskin LS

Department of Urology and Pediatrics, University of California-San Francisco Children's Medical Center, University of California-San Francisco, San Francisco, California, USA

J Urol. 2004; 172: 191-5

PURPOSE: The neuroanatomy of the female lower urogenital tract remains controversial. We defined the topographical anatomy and differential immunohistochemical characteristics of the dorsal nerve of the clitoris, the cavernous nerve and the nerves innervating the female urethral sphincter complex.

METHODS: A total of 16 normal female human pelvic specimens at 14 to 34 weeks of gestation were studied by immunohistochemical techniques. Serial sections were stained with antibodies raised against the neuronal markers S-100 and neuronal nitric oxide synthase (nNOS), vesicular acetylcholine transporter, calcitonin gene-related peptide and substance P. The serial sections were computer reconstructed into 3-dimensional images.

RESULTS: Under the pubic arch at the hilum of the clitoral bodies, the branches of the cavernous nerves joined the clitoral dorsal nerve to transform its immunoreactivity to nNOS positive. The cavernous nerves originated from the vaginal nervous plexus occupying the 2 and 10 o'clock positions on the anterolateral vagina and they traveled at the 5 and 7 o'clock positions along the urethra. The urethral sphincter complex was innervated by nNOS immunoreactive and nonimmunoreactive nerve fibers arising from the vaginal nervous plexus and pudendal nerve, respectively.

CONCLUSIONS: The dorsal nerve of the clitoris receives nNOS positive branches from the cavernous nerve as a possible redundant mechanism for clitoral erectile function. The urethral sphincter complex has dual innervation, which pierces into the urethral sphincter complex at different locations. The study of the neuroanatomy of the female lower urogenital tract is germane to the strategic design of female reconstructive surgery.

Editorial Comment

This is the second paper on the neuroanatomy of the human clitoris of this group. They examined female human fetal pelvic specimens with regards to neural immunoreactivity. In an elegant study, they were able to demonstrate findings, which are important for some of the more recently available reconstructive techniques in women undergoing pelvic floor or pelvic surgery.

nNOS immunoreactive nerve fibers were demonstrated in the distal clitoris but not in the proximal clitoris. It might be speculated that NO not only plays an important role in female sexual physiology but also that these specific nerves derive from the cavernous within the clitoral bodies and therefore are supplied by the pelvic autonomic nerves.

The location of these autonomic pelvic nerves were seen at the level of the urethra at the 5 and 7 o'clock joining more cranially the more nervous complex located at the anterior lateral sides of the vagina at the 2 and 10 o'clock positions. There was also a nNOS non-immunoreactive but otherwise autonomic nerve entering the muscular layer of the urethral sphincter complex at the mid urethra. There were no other autonomic nerves seen in the mid urethra.

The location of a dense network of autonomic nerves at the level of the vagina supplied by the inferior hypogastric plexus occupying the 2 and 10 o'clock positions at the rectum mainly at the lateral and anterior vaginal wall which were thinning out on the anterior wall towards the urethra. From there, fibers traveled either along the pathways described above towards the clitoris or towards the proximal a mid urethral sphincter.

We learn from these studies for complex surgical procedures at the level of the pelvic floor and urethra to maintain micturition, continence and sexuality in female patients the preservation of autonomic nerves is mandatory and must put there pathways within the whole pelvis into consideration. Further studies will have to follow to demonstrate the functional value and possible changes in adulthood but definitely these data warned consideration during surgery.