ISSM – Abstract – October 2015
Risk of Damage to the Somatic Innervation of the Penis during the AdVance™ Procedure: An Anatomical Study
Cornelis R.C. Hogewoning MD; Henk W. Elzevier MD, PhD; Rob C.M. Pelger MD, PhD; Milou D. Bekker MD, PhD; and Marco C. DeRuiter PhD
ONLINE: July 2, 2015 – The Journal of Sexual Medicine
Stress urinary incontinence (SUI) and erectile dysfunction (ED) are two complications of radical prostatectomy. SUI rates as high as 87% have been reported in medical literature, but outcomes can be influenced by surgical techniques and different definitions of continence.
Even with the advent of robot-assisted laparoscopic prostatectomy, postoperative SUI rates are estimated to be between 5% and 48%.
The most common form of SUI after radical prostatectomy is sphincter incompetence. When therapies like lifestyle changes and pelvic floor muscle training are not effective, surgical procedures such as placement of a sling or artificial urinary sphincter are considered.
The AdVance™ system is one type of male sling offered, and is typically considered for mild to moderate urinary incontinence. “The AdVance™ repositions the urethral sphincter complex in the pelvis and is designed to minimize the risk of tissue damage during placement,” the study authors explained.
In their clinic, one patient undergoing the procedure experienced neurotmesis of the dorsal nerve of the penis (DNP). The DNP is an essential nerve for sexual function, as it transmits sensory input from the penis to the central nervous system. It is involved with erection, orgasm, and ejaculation.
Since no similar complications had been reported in the literature with AdVance™ sling placement, the study authors sought to define the anatomical relationship between this particular male sling and penile nerves using a cadaveric model.
The bodies of six Caucasian men were used. None of the bodies showed signs of previous pelvic surgery. The men were age 70 or older at the time of death.
The same researcher performed all procedures. First, an AdVance™ male sling was placed in each body. Next, the pelves were separated and dissected so that the sling, obturator vessels and nerves could be identified.
The distances between the AdVance™ male sling, the DNP, and the obturator neurovascular bundles were measured.
The DNP did not follow an aberrant course in any of the pelves. The mean distance from the sling to the DNP was 4.1 mm. In 4 of the 12 hemipelves, the sling was directly next to the DNP (0 mm). No sign of nerve damage by the trochar or sling was found in any of the pelves. In all six, the distance between the sling and the obturator neurovascular bundle was 30 mm or more.
Neither a literature review nor the results of this anatomical study could explain why the clinic patient had neurotmesis of the DNP as a result of AdVance™ sling placement. Thus, the authors offered these possible explanations:
• Neurotmesis of the DNP could have occurred at other clinics, but was not reported by patients or physicians in the medical literature.
• In the clinic patient, the DNP might have taken an aberrant course through the pelvis, making it more susceptible to damage.
• The DNP might have been damaged directly after the sling placement, when the sling was tensioned.
• The surgeon may have placed the sling incorrectly.
The authors acknowledged two limitations of the study. First, only six bodies were used, which makes it difficult to reproduce rare complications. Second, none of the bodies had a history of radical prostatectomy.
Larger, in vivo research could provide more insight. In the meantime, physicians and patients should be aware of this risk when choosing male sling surgery, the authors noted.