BlueCross and BlueShield of Montana Medical Policy/Codes
Nerve Graft in Association with Radical Prostatectomy
Chapter: Surgery: Procedures
Current Effective Date: October 25, 2013
Original Effective Date: October 25, 2013
Publish Date: July 25, 2013
Description

Nerve grafting to replace cavernous nerves resected at the time of radical prostatectomy is proposed to reduce the risk of erectile dysfunction after this surgery. The sural nerve is most commonly used in grafting.

Background

Erectile dysfunction is a common problem after radical prostatectomy. In particular, spontaneous erections are usually absent in patients whose extent of prostate cancer requires bilateral resection of the neurovascular bundles as part of the radical prostatectomy procedure. A variety of noninvasive treatments are available, including vacuum constriction devices and intracavernosal injection therapy. However, spontaneous erectile activity is preferred by patients. Studies have reported results from bilateral nerve grafts; there are also reports of unilateral grafts when only one neurovascular bundle has been resected.

There has been interest in sural nerve grafting to replace cavernous nerves resected at the time of prostatectomy. The sural nerve is considered expendable and has been used extensively in other nerve grafting procedures, such as brachial plexus and peripheral nerve injuries. As applied to prostatectomy, a portion of the sural nerve is harvested from one leg and then anastomosed to the divided ends of the cavernous nerve. Reports are also being published using other nerves, such as the genitofemoral nerve.

Policy

Each benefit plan, summary plan description or contract defines which services are covered, which services are excluded, and which services are subject to dollar caps or other limitations, conditions or exclusions. Members and their providers have the responsibility for consulting the member's benefit plan, summary plan description or contract to determine if there are any exclusions or other benefit limitations applicable to this service or supply.  If there is a discrepancy between a Medical Policy and a member's benefit plan, summary plan description or contract, the benefit plan, summary plan description or contract will govern.

Coverage

Unilateral or bilateral nerve graft in patients who have undergone resection of one or both neurovascular bundles as part of a radical prostatectomy is considered experimental, investigational and unproven.

Rationale

The first randomized controlled trial (RCT) that evaluated nerve grafting was published in 2009 by Davis and colleagues. (1) Eligibility criteria included age 65 years or younger, normal self-report baseline erectile function, and scheduled for a unilateral nerve-sparing radical prostatectomy with preservation of one neurovascular bundle. All patients had the other neurovascular bundle removed, and patients were randomly assigned to receive or not receive sural nerve-grafting after its removal. The primary outcome was potency 2 years post-surgery, defined as the ability to have intercourse with or without erectile dysfunction medication. The investigators estimated that the control group would have a 40% potency rate and powered the study to detect an absolute difference of 20% between groups. All patients received the same early erectile dysfunction therapy including medication and mechanical devices. A sample size of 200 was originally planned to provide 80% power. However, after 107 patients were randomly assigned, a pre-planned interim analysis of evaluable patients found similar rates of potency in the 2 groups; the Data Monitoring Committee estimated that there was less than a 5% chance that there would be a significant difference between groups with additional recruitment and the trial was stopped early. When data collection ended, endpoint data were available for 66 patients who had either achieved potency or had been followed up for 2 years without potency. Potency was achieved in 32 of 45 (71%) sural nerve-graft patients and 14 of 21 (67%) control patients (p=0.78). The authors concluded that unilateral sural nerve-graft did not result in an absolute improvement of 20% in the rate of potency but that a smaller effect cannot be ruled out. A limitation of the study was that it was non-blinded, which could have impacted self-report of potency.

Other than the Davis et al. study, the published literature consists of case series. When the initial literature search was performed, the largest available series included 23 men with a mean of 23-month follow-up. (2) This study, by Kim et al., included men with clinically localized but high-volume prostate cancer such that bilateral resection of the neurovascular bundles was considered necessary. Before surgery, all men reported spontaneous erection. The results were compared to a group of 12 men who were potent preoperatively and had undergone prostatectomy with bilateral nerve resection but who declined nerve-graft placement. Of the 23 men undergoing nerve grafting, 6 (26%) had spontaneous, medically unassisted erection sufficient for sexual intercourse. An additional 6 men (26%) reported 40% to 60% spontaneous erection that was insufficient for intercourse; 4 of these patients were able to have intercourse using sildenafil. Therefore, a total of 10 of the 23 patients were able to have intercourse, either spontaneously or with pharmacologic therapy. A total of 11 men had no clinical response even with the use of sildenafil. Not unexpectedly, all outcomes were significantly better compared to the control group. Side effects of the sural nerve donor site, which included incisional pain and a sensory deficit along the lateral aspect of the foot, were considered tolerable. The authors noted improvement 8 to 12 months postoperatively and accelerated improvement at 12 to 18 months postoperatively.

In 2007, Namiki and colleagues published a series in Japan with 3-year follow-up.(3) A total of 113 patients were evaluated: 19 patients with unilateral nerve-sparing plus sural nerve graft, 60 patients with unilateral nerve-sparing but no grafting, and 34 patients with bilateral nerve-sparing surgery. Sexual function was assessed with validated questionnaires, and at 2 years, there was no difference between the nerve-grafted and the bilateral nerve-sparing patients with regard to sexual function scores. At 3 years, 25% and 28% of patients in the nerve-grafted and bilateral nerve-sparing groups, respectively, considered their sexual function as fair or good. Urinary function returned to baseline in the nerve-grafted and bilateral nerve-sparing groups at 6 months and in the unilateral nerve-sparing group at 12 months. Differences in sexual function were present at baseline with the nerve-grafted and bilateral nerve-sparing patients reporting higher baseline function than the unilateral nerve-sparing group.

A study by Secin and colleagues had 5-year follow-up. (4) The authors reported results on 44 consecutive patients who underwent bilateral nerve grafting from 1999 to 2004 at Memorial Sloan-Kettering Cancer Center. The overall 5-year recovery of erectile function was 34%, and the rate of consistent function was 11%. None of a number of variables (e.g., age, type of nerve [sural, genitofemoral, ilioinguinal], comorbidities) was significantly associated with recovery of postoperative erectile function.

Sim et al. reported on 2-year results in 41 patients who received unilateral sural nerve grafts following radical prostatectomy when 1 neurovascular bundle was resected.(5) In this series, recovery of erectile function was reported for 63% of patients (based on 24 of 38 patients). This study also reported on erectile function on another group of patients who had unilateral resection at the same institution but without a nerve graft. In this group, which was older and was not matched on key characteristics to the group who received a nerve graft, the erectile function was 26.5% (13 of 49).

A recent case series reviewed the records of 131 men who had unilateral nerve grafts after radical prostatectomy with unilateral neurovascular bundle resection. (6) Men who had prior radiation or hormonal treatment were excluded. Another eligibility criterion was satisfactory erections presurgery as assessed by a 5-point scale (1=full erections; 2=diminished erections, but routinely sufficient for sexual intercourse; 3=partial erections occasionally satisfactory for intercourse; 4=partial erections unsatisfactory for intercourse; and 5=no erections). A total of 49 men received sural nerve grafts, 79 received genitofemoral nerve grafts, and 3 received ilioinguinal nerve grafts. Recovery of erections was evaluated at each follow-up visit according to the 5-point scale (also called 5 levels). The median patient age was 58.7 years, and the median follow-up was 37 months. According to actuarial analysis, the 5-year probability of recovering erections of level 3 or better was 46%. The probability of recovering erections of at least level 2 or level 1 was 34% and 12%, respectively.

Ongoing Clinical Trials

A search of the online ClinicalTrials.gov database in October 2011 did not identify any ongoing trials on nerve grafting but did identify a single-arm pilot study on a related topic, nerve reconstruction in conjunction with robotic-assisted prostatectomy. (7) The study evaluates the use of AVANCE, an allograft tissue product, for nerve reconstruction and is sponsored by the manufacturer of AVANCE. Technical feasibility is the primary outcome, and erectile function is one of the secondary outcomes. As of August 2013, this study is active and no longer recruiting participants. No reports have been published to date. 

Summary

Nerve-grafting, most commonly using the sural nerve, at the time of radical prostatectomy has been proposed to reduce the risk of postoperative erectile dysfunction. Only one randomized controlled trial that evaluated sural nerve-grafting with radical prostatectomy has been published, and this study did not find that unilateral nerve-grafting was associated with a statistically significant improvement in potency rates 2 years post-surgery. Due to the negative findings of this study, and the lack of other controlled studies evaluating unilateral or bilateral nerve grafting, the technique is considered experimental, investigational and unproven.

Practice Guidelines and Position Statements

The 2012 National Comprehensive Care Network (NCCN) prostate cancer guideline states that replacement of resected nerves has not been shown to be beneficial for recovery of erectile function after radical prostatectomy. (8)

2013 Update

A search of peer reviewed literature through July 2013 identified no new clinical trial publications or any additional information that would change the coverage position of this medical policy.

Coding

Disclaimer for coding information on Medical Policies          

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy.  They may not be all-inclusive.           

The presence or absence of procedure, service, supply, device or diagnosis codes in a Medical Policy document has no relevance for determination of benefit coverage for members or reimbursement for providers.  Only the written coverage position in a medical policy should be used for such determinations.           

Benefit coverage determinations based on written Medical Policy coverage positions must include review of the member’s benefit contract or Summary Plan Description (SPD) for defined coverage vs. non-coverage, benefit exclusions, and benefit limitations such as dollar or duration caps. 

ICD-9 Codes

185, 233.4, 607.84, 997.99, V45.77

ICD-10 Codes

C61, D07.5, N52.01, N52.02, N52.03, N52.1, N52.2,.N52.31, N52.32, N52.33, N52.34, N52.39, N52.8, N52.9, Z90.79, 0VT00ZZ

Procedural Codes: 55899, 64999
References
  1. Davis JW, Chang DW, Chevray P et al. Randomized phase II trial evaluation of erectile function after attempted unilateral cavernous nerve-sparing retropubic radical prostatectomy with versus without unilateral sural nerve grafting for clinically localized prostate cancer. Eur Urol 2009; 55(5):1135-43.
  2. Kim ED, Nath R, Slawin KM et al. Bilateral nerve grafting during radical retropubic prostatectomy: extended follow-up. Urology 2001; 58(6):983-7.
  3. Namiki S, Saito S, Nakagawa H et al. Impact of unilateral sural nerve graft on recovery of potency and continence following radical prostatectomy: 3-year longitudinal study. J Urol 2007; 178(1):212-6; discussion 16.
  4. Secin FP, Koppie TM, Scardino PT et al. Bilateral cavernous nerve interposition grafting during radical retropubic prostatectomy: Memorial Sloan-Kettering Cancer Center experience. J Urol 2007; 177(2):664-8.
  5. Sim HG, Kliot M, Lange PH et al. Two-year outcome of unilateral sural nerve interposition graft after radical prostatectomy. Urology 2006; 68(6):1290-4.
  6. Rabbani F, Ramasamy R, Patel MI et al. Predictors of recovery of erectile function after unilateral cavernous nerve graft reconstruction at radical retropubic prostatectomy. J Sex Med 2010; 7(1 Pt 1):166-81.
  7. Study of nerve reconstruction using AVANCE in subjects who undergo robotic assisted prostatectomy for treatment of prostate cancer (NCT00953277). Available online at: www.ClinicalTrials.gov . Last accessed November, 2012.
  8. National Comprehensive Cancer Network. Prostate Cancer. Clinical practice guidelines in oncology, v3.2012. Available online at: <nccn.org>Last accessed August 2013.
  9. Nerve Graft in Association with Radical Prostatectomy. Chicago, Illinois: Blue Cross Blue Shield Association Medical Policy Reference Manual (2013 July) Surgery 7.01.81.
History
July 2013  New 2013 BCBSMT medical policy.  Unilateral or bilateral nerve graft in patients who have undergone resection of one or both neurovascular bundles as part of a radical prostatectomy is considered experimental, investigational and unproven. 
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Nerve Graft in Association with Radical Prostatectomy