Nerve Wrap May Hasten Potency Return
The average time to return of continence and potency following prostatectomy was significantly shorter in the allograft than no-allograft group.
Wrapping a dehydrated human amniotic membrane allograft around the prostatic neurovascular bundle (NBV) during nerve-sparing robot-assisted laparoscopic radical prostatectomy (RARP) holds promise as a way to hasten return of continence and potency after surgery, according to a new study.
Vipul R. Patel, MD, of the Global Robotics Institute, Florida Hospital- Celebration Health in Celebration, Fla., and colleagues studied a cohort of 58 men who were continent and potent prior to undergoing RARP and who received the allograft. The researchers compared these patients with a propensity score-matched group of 58 RARP patients who did not receive the allograft.
The allograft was cut into 2 longitudinal pieces and placed over each NVB as a nerve wrap, which was placed circumferentially around the NVB after extirpative RARP, following anastomosis.
At 8 weeks, continence and potency returned in 81% and 65.5% of the allograft group, respectively, and 74.1% and 51.7%, respectively, of the no-allograft group, Dr. Patel's group reported online ahead of print in European Urology. These between-group differences were not statistically significant, but the mean time to return of continence was significantly shorter in the allograft than no-allograft group (1.21 vs. 1.83 months) and the mean time to return of potency was significantly shorter in the allograft than no-allograft group (1.34 vs. 3.39 months). In addition, postoperative scores on the Sexual Health Inventory for Men questionnaire were significantly higher in the allograft than no-allograft group at maximal follow-up (16.2 vs. 9.1).
The authors explained that despite RARP's advantages, even patients with well-preserved NVBs experience a convalescent period characterized by incontinence and impotence.
The researchers noted that they have been awaiting the next step in innovation that transcends the technical aspect of nerve sparing by biologically altering the prostatic NVB neuropraxia induced by surgical dissection. Clinical use of growth factors and anti-inflammatory substances for prostatic NBV regeneration is novel, and dehydrated human amniotic membrane is source of implantable neurotrophic factors and cytokines, Dr. Patel and his colleagues explained.
“While this approach appears promising, like any new advance, the scientific process will take its own time before we can pinpoint its impact on nerve and tissue regeneration,” said Ash Tewari, MBBS, MCh, Kyung Hyun Kim, MD Chair in Urology, Icahn School of Medicine at Mount Sinai and Chairman, Milton and Carroll Petrie Department of Urology at the Mount Sinai Health System in New York.
Dr. Tewari, who has performed more than 5,000 robotic radical prostatectomies, noted that recovery of urinary and sexual function following nerve-sparing prostatectomy is a multifactorial process involving baseline medical and anatomical variables, a nerve-sparing technique, a continence-sparing approach, postoperative rehabilitation, and the body's ability to heal, which is determined by tissue injury, ischemia, inflammation, and residual scarring.
“Optimal recovery requires a perfect interplay between these diverse processes, and dehydrated human amniotic membrane allograft nerve wrap could minimize excessive inflammation and scarring,” said Dr. Tewari, who added that he and his colleagues have submitted an application to his hospital's institutional review board to study the utility of this membrane in their patients.