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

Regeneration and functional recovery of intrapelvic nerves removed during extensive surgery by a new artificial nerve conduit: a breakthrough to radical operation for locally advanced and recurrent rectal cancers

PURPOSE

In the current strategy against locally advanced and recurrent rectal cancers possibly involving intrapelvic nerves, there has been a serious dilemma between extensive surgery and limited surgery. The former can attain high tumor curability by sacrificing the nerve functions while the latter prioritizes the patient quality of life by preserving the nerve functions but with a compromised curability. Here we present a new surgical strategy for locally advanced and recurrent rectal cancers, which realize both high tumor curability and good quality of life.

METHODS

A new artificial nerve conduit (polyglycolic acid collagen tube) developed by in site tissue engineering technology was applied to recovery the disturbed functions after removing the nerves from 11 patients undergoing extensive surgery for intrapelvic advanced or recurrent colorectal cancers. The reconstructed nerves included eight autonomic nerves which are essential for the genitourinary function and three somatic nerves which control the sensation and mobility of the legs.

RESULTS

Out of ten cases followed up more than 2 years and evaluated fully, eight including two report cases showed a functional recovery of the disturbed autonomic and somatic nerves clinically. The nerve function started to recover from 3 to 6 months after the operation and continued to improve with times. No specific complications associated with the nerve repair have been noted.

CONCLUSIONS

The new strategy utilizing the nerve conduit can be a breakthrough in radical operations for locally advanced and recurrent rectal cancers to resolve the problems between tumor curability and the patient quality of life.

Nerve Advancement with End-to-End Reconstruction after Partial Neurovascular Bundle Resection:A Feasibility Study

BACKGROUND AND PURPOSE

It is clear that some patients with prostate cancer require a total or partial neurovascular bundle (NVB) resection for oncologic safety to be guaranteed. Nerve grafting is an alternative for these patients to maintain erectile function; however, we report on a feasible option where the NVB is released, and both terminal nerve fibers are approximated; this is the "nerve advancement technique (NAT)."

PATIENTS AND METHODS

Since 2005, a total of 215 men aged 48 to 70 years (mean 59 years) with a Sexual Health Inventory for Men (SHIM) score of 22 have undergone robotic radical prostatectomy for cancer. We selected prospectively seven men to have NAT performed because of clinical high-risk criteria (serum prostate specific antigen [PSA] concentration >20 mg/dL, Gleason score = 8, and stage cT(2c) or higher), intraoperative criteria (difficulty separating the tissues around the prostate), and evidence of extracapsular extension (ECE) on magnetic resonance imaging. We performed unilateral partial resection, nerve advancement, and, finally, end-to-end anastomosis in six patients, whereas in one patient, we did a bilateral partial excision. We analyzed the results in terms of oncologic safety (positive surgical margins and PSA) and SHIM score after 18 months of follow-up.

RESULTS

Pathologic examination revealed stage T3 disease in six patients; one had a positive surgical margin. Two patients are receiving salvage radiotherapy for PSA relapse, and five continue to have undetectable PSA concentrations after a median follow-up of 20 months. Five of the seven men recovered erectile potency with or without a phosphodiesterase inhibitor, and their median SHIM score is 18.

CONCLUSIONS

We are encouraged by the initial results of NAT. The procedure may be an alternative for men who require extensive NVB dissection. However, further experience, longer follow-up, and independent trials are necessary.

Cavernous nerve graft reconstruction using an autologous nerve guide to restore potency

OBJECTIVE

To present our experience of cavernous nerve graft reconstruction, using an autologous nerve vein-guide technique, to restore potency.

PATIENTS AND METHODS

Prostate cancers frequently require radical resection involving one or both cavernous nerves that usually results in erectile dysfunction; nerve grafting has been used to restore erectile function, but clinical results are unsatisfactory owing to inadequate surgical techniques. In all, eight patients with prostate cancer who required radical resection involving one cavernous nerve had sural nerve grafting, with two or three sutures using the autologous vein-guide technique, in our unit between 2004 and 2005. Because of the difficulty of performing microsurgical manoeuvres deep within the pelvic cavity, the nerve anastomosis might be unsatisfactory.

RESULTS

Seven of the eight patients had spontaneous erectile activity after grafting and six of these patients were able to have intercourse.

CONCLUSION

Sural nerve grafting using the autologous vein-guide technique is simple, has minimal morbidity, and yields good outcomes.