Evaluation of Genitofemoral Nerve Donor Site Morbidity After Radical Prostatectomy

Recovery of erectile function after unilateral and bilateral cavernous nerve interposition grafting during radical pelvic surgery

PURPOSE

The use of cavernous nerve interposition grafting to preserve erectile function in men who require neurovascular bundle resection for cancer control is controversial. We report outcomes and predictors of cavernous nerve interposition grafting in men undergoing unilateral grafting during radical prostatectomy or bilateral grafting during radical cystectomy and prostatectomy with autologous nerve grafts.

MATERIALS AND METHODS

We retrospectively reviewed the electronic records of 36 patients who underwent cavernous nerve interposition grafting between 2003 and 2006. Postoperatively erectile function was assessed with the International Index of Erectile Function 15-item questionnaire. Predictors of potency, including age at surgery, time since surgery and prostate specific antigen at surgery, were assessed by univariate analysis.

RESULTS

A total of 33 patients (92% response rate) were followed for a median of 32, 25 and 11 months after bilateral grafting during radical cystectomy (10), unilateral grafting during radical prostatectomy (20), and bilateral grafting during radical cystectomy and prostatectomy (3), respectively. The rate of potency, defined as the ability to attain and maintain erection sufficient for penetration at least 50% of the time with or without phosphodiesterase-5 inhibitors, was 31% (5 of 13 men) for unilateral grafts, 38% (5 of 16) for bilateral grafts and 30% (3 of 10) for bilateral grafts during radical cystectomy. Age at surgery was the only significant determinant of potency and it showed an inverse relationship in the bilateral nerve graft group (p = 0.02).

CONCLUSIONS

Cavernous nerve interposition grafting appears to have a role in the recovery of erectile function. To our knowledge this study represents the largest series of cavernous nerve interposition grafting during cystectomy and it suggests that this should be considered during bilateral neurovascular bundle resection.

Results of unilateral genitofemoral nerve grafts with contralateral nerve sparing during radical prostatectomy

OBJECTIVES

To evaluate the success of erectile function preservation and recovery in a select group of patients with extensive disease unilaterally on biopsy who were candidates for unilateral nerve sparing and contralateral genitofemoral interposition nerve-grafting radical prostatectomy (RP). Because of its low donor site morbidity, the genitofemoral nerve is an appealing donor source for cavernous nerve grafting during RP. Although evidence has shown that sural interposition nerve grafts during RP preserve erectile function, the evidence for genitofemoral nerve grafts is limited.

METHODS

Nerve-sparing RP was performed according to the technique of Walsh on 22 patients with prostate cancer. At follow-up, the patients completed an 11-item self-report questionnaire that included the erectile function (EF) domain of the International Index of Erectile Function.

RESULTS

The mean patient age was 62 years (range 48 to 76). The mean follow-up time was 23 months (range 9 to 37). Of the 22 patients, 3 reported no erectile dysfunction (ED) (EF score 26 to 30), 3 reported mild ED (EF score 22 to 25), 1 reported moderate ED (EF score 11 to 16), and 15 reported severe ED (EF score less than 11). Eight men continued to experience mild chronic thigh or scrotal numbness after the genitofemoral nerve graft procedure.

CONCLUSIONS

The benefits of unilateral nerve grafting with the genitofemoral nerve remain uncertain. A prospective randomized trial is warranted before the widespread adoption of unilateral nerve grafting.

Two-year outcome of unilateral sural nerve interposition graft after radical prostatectomy

OBJECTIVES

To study 41 men treated for prostate cancer with unilateral nerve-sparing radical prostatectomy and contralateral sural nerve grafting from January 2000 to September 2003.

METHODS

Patients were considered for sural nerve grafting if they were considered at high risk of extracapsular extension before or during surgery, were younger than 70 years of age with good preoperative erectile function, were sexually active, and had no significant risk factors for erectile dysfunction. Potency was assessed by patient-reported questionnaires, including the International Index of Erectile Function erectile domain and Rigiscan testing.

RESULTS

The mean follow-up was 27.4 +/- 14.5 months. At 24 months, 24 (63.2%) of 38 men had erections sufficient for intercourse, with or without phosphodiesterase type 5 inhibitor use. Four men had partial erections that were occasionally satisfactory (10.5%), and 10 men reported no sexual activity, no spontaneous erections, or partial erections unsatisfactory for intercourse (26.3%). In contrast, in a group of 49 men who underwent unilateral nerve-sparing prostatectomy without nerve grafting during the same period at our institution, 13 (26.5%) had rigid erections adequate for intercourse with or without phosphodiesterase type 5 inhibitor use at 24 months of follow-up.

CONCLUSIONS

At 24 months of follow-up, men who had undergone unilateral nerve-sparing prostatectomy with contralateral sural nerve interposition graft repair of a cut cavernosal nerve had a greater rate of return of erectile function than men undergoing unilateral nerve-sparing prostatectomy alone.

Reconstruction of cavernous nerves by nerve grafts to restore potency: contemporary review of technical principles and basic anatomy

PURPOSE OF REVIEW

The review discusses the efficacy of reconstructing the neurovascular bundle to regain sexual function if nerve-sparing prostatectomy is unfeasible.

RECENT FINDINGS

Eleven studies could be found describing the reconstruction of neurovascular bundles. All reconstructive procedures displayed technical inadequacies. The effectiveness of unilateral neurovascular bundle reconstruction remains statistically insignificant when compared with procedures without reconstruction. The efficacy of reconstructing both neurovascular bundles ranges between 0 and 43%. Concerning basic anatomy, the neurovascular bundle contains fibers innervating the cavernous nerves, prostate, rectum, and levator ani muscle. The terms cavernous nerve and neurovascular bundle have often been wrongly considered synonymous. The pelvic splanchnic nerves probably do not join the neurovascular bundle proximal to the bladder/prostate junction but rather at variable distances from 10 to 20 mm distal to it. Therefore, described proximal coaptation sites at the bladder/prostate junction possibly encompass only the hypogastric nerve.

SUMMARY

Modest clinical results are partly due to inadequate surgical techniques and are mainly due to the anatomical and topographical complexity of the cavernous nerves. Contemporary nerve grafting techniques probably do not allow for the regeneration of all cavernous nerves.