INTERPOSITION OF SURAL NERVE RESTORES FUNCTION OF CAVERNOUS NERVES RESECTED DURING RADICAL PROSTATECTOMY:

Recent neuroanatomical studies on the neurovascular bundle of the prostate and cavernosal nerves: clinical reflections on radical prostatectomy

The neurovascular bundle of the prostate and cavernosal nerves have been used to describe the same structure ever since the publication of the first studies on the neuroanatomy of the lower urogenital tract of men, studies that were prompted by postoperative complications arising from radical prostatectomy. In urological surgery every effort is made to preserve or restore the neurovascular bundle of the prostate to avoid erectile dysfunction (ED). However, the postoperative potency rates are yet to be satisfactory despite all advancements in radical prostatectomy technique. As the technology associated with urological surgery develops and topographical studies on neuroanatomy are cultivated, new observations seriously challenge the classical teachings on the topography of the neurovascular bundle of the prostate and the cavernosal nerves. The present review revisits the classical and most recent data on the topographical anatomy of the neurovascular bundle of the prostate and cavernosal nerves and their implications on radical prostatectomy techniques.

Is laparoscopic unilateral sural nerve grafting during radical prostatectomy effective in retaining sexual potency?

OBJECTIVES

To present a pilot study of laparoscopic unilateral sural nerve grafting during radical prostatectomy, with the aim of preserving sexual potency.

PATIENTS AND METHODS

Because they had localized prostate cancer, 29 men had a laparoscopic radical prostatectomy with deliberate wide unilateral neurovascular bundle resection and preservation of the contralateral bundle. Fifteen men (group A) had an interposition sural nerve graft on the sectioned bundle, and 14 (group B) had laparoscopic radical prostatectomy with preservation of the unilateral bundle only. The men were also involved in a rehabilitation programme, and erectile function was evaluated after surgery, and at 3, 8, 12 and 18 months, using the five-item version of the International Index of Erectile Function (IIEF-5) questionnaire.

RESULTS

The two groups had similar clinical characteristics (age, prostate-specific antigen level, body mass index, prostate volume, clinical stage, Gleason score before and after surgery, postoperative stage). The follow-up was complete for 12 men in group A and 10 in group B. Group A had significantly higher erectile function scores on the IIEF-5 at 12 and 18 months than immediately after surgery (P < 0.01), whereas in group B the improvement was not statistically significant. Overall, by 18 months after surgery five of 12 men in group A had achieved spontaneous unassisted erection or erection assisted with sildenafil, while three of 10 in group B achieved an erection assisted with sildenafil (not significant).

CONCLUSIONS

These data suggests that laparoscopic sural nerve grafting during radical prostatectomy is feasible and safe; nevertheless we cannot conclude that sural nerve grafting is more effective than preserving the neurovascular bundle alone in retaining sexual potency. More research is required to validate the effectiveness of this technique.

Neuroprotective strategies in radical prostatectomy

In this section, authors from New York give their views on the various neuroprotective strategies for patients having a radical prostatectomy, such as the use of nerve grafts and other approaches. A joint study from Korea, the USA, Canada and the UK is presented in a paper on the importance of patient perception in the clinical assessment and management of BPH. There is also a review of robotic urological surgery. Finally, authors from New York give a review on the life of Isaac Newton. This is a new historical review in the journal, but one that will be of general interest.

Cavernosal nerve mapping: current data and applications

Although nerve-sparing prostatectomy is widely practised, the results with respect to preserving potency often do not meet expectations. The concept of intraoperative cavernosal nerve stimulation is reasonable. Data that link the response to sildenafil after prostatectomy with bilateral nerve sparing has increased the importance of optimizing nerve sparing. The cavernosal nerves are often difficult to visualize and may have a variable course. A tumescent response to nerve stimulation can be shown consistently; the response may be subtle, and characterized by a minimal increase in penile circumference and blood flow. Immediately after prostatectomy, proximal nerve stimulation identifies whether neural continuity has been maintained, and is predictive of recovery of erectile function. The Cavermap system (Uromed Corporation, Boston, MA, USA) was developed to permit intraoperative nerve stimulation with tumescence monitoring. An initial phase 2 and subsequent phase 3 single-blinded, randomized, multicentre study that compared Cavermap-assisted prostatectomy with conventional nerve sparing showed a significant benefit in terms of the duration of nocturnal tumescence at 1 year. Other approaches are being explored, including incorporating the device into sural or genito-femoral nerve grafting, use of nerve stimulation during cystectomy or abdominal-perineal resection, and direct corpus cavernosal pressure monitoring during nerve stimulation. These approaches warrant further evaluation.

The treatment of prostate cancer: an overview of current options

PURPOSE

The purpose of this report is to discuss the current treatment options available to the patient with prostate cancer in all stages of the disease.

OVERVIEW

With the exception of skin cancer, prostate cancer is the most common cancer in men in the United States. Most patients in the current era will present with organ-confined disease, amenable to curative treatment. Treatment for organ-confined disease includes watchful waiting, radical prostatectomy, radiation therapy, and cryosurgery in selective cases. Hormone therapy is the cornerstone of treatment of patients with advanced prostate cancer. There is no curative treatment for hormone-refractory prostate cancer.

CLINICAL IMPLICATIONS

The availability of several therapeutic options for localized prostate cancer warrants careful consideration when planning treatment with curative intent. Patients need to be active participants in decision making, and they must be aware of the benefits and possible complications of the different types of treatment. Patients with advanced prostate cancer need to be aware that hormone treatment will provide temporization and palliation in the majority of cases. Hormone-resistant prostate cancer is refractory to most forms of conventional and experimental therapy.