Protecting Nerves: Burnett's discovery with Johns Hopkins neuroscientist Solomon Snyder that nitric oxide plays a crucial role in erection led to development of the drug Viagra for erectile dysfunction. For nearly three decades, much of his lab and clinical work has focused on protecting the integrity of the neurovascular bundles responsibile for erection, easily damaged even in the "nerve-sparing" radical prostatectomy developed by Johns Hopkins urologist Patrick Walsh, MD. "It may even be from traction, or even that the adjacent dissection somehow exposes the nerves to injury," Burnett says, "Something causes them to sustain an inflammatory setback."
In groundbreaking studies of rats with nerve injury and erectile dysfunction similar to that found in men after radical prostatectomy, he has tested many inflammation-fighting agents and growth factors designed to "preserve, nourish, regenerate and restore nerves to normal function." One of these is an agent used to combat anemia, erythropoeitin (EPO). Burnett previously led studies investigating the effects of EPO on erectile function recovery in a rat model of cavernous nerve injury; and now he is investigating those promising results in humans. In a randomized, controlled clinical trial, still actively enrolling patients, Burnett is studying EPO's ability to enhance nerve function. EPO is injected the day before, the day of, and the day after radical prostatectomy.
In other work, Burnett has targeted the fragile network of blood vessels and chambers within the penis. Even though they're not directly traumatized by surgery, "these structures may degenerate or shrivel," he says, "and thus contribute to poor recovery of erectile function in some men after surgery." To fight this, Burnett is testing such blood vessel-strengthening agents as angiotensin II type 1 receptor antagonists. In another clinical trial, he is testing an external vibration nerve-stimulatory device, which he helped develop, that may be applied under a specific protocol after surgery.
If you, a loved one, or a patient is interested in one of Dr. Burnett's trials, please call the Urology Clinic at the Brady Urological Institute (410) 955-6100 for an appointment with Dr. Burnett.
Help for incontinence and impotence: Having both urinary incontinence and impotence after radical prostatectomy should be a rare complication, but some men find themselves in this situation and need help. For the last 13 years, Burnett has offered a successful operation that restores urinary continence and potency at the same time --- implantation of an inflatable penile prosthesis and an artificial urinary sphincter. "It provides efficient and rapid resumption of both functional disorders, " he says.
Burnett is also conducting further research into utilization and prediction modeling for penile prosthesis surgery. Dr. Burnett explains,
"Our goal is to approach everything we do thoughtfully and rigorously, so that we can make advances based on what is scientifically meaningful."
This blog entry is extracted from the "Johns Hopkins Urology: News for Physicians from Johns Hopkins Medicine," Spring 2014.
 Burnett AL, Lowenstein CJ, Bredt DS, Chang TS, Snyder SH. Nitric oxide: a physiologic mediator of penile erection. Science. 1992 Jul 17;257(5068):401-3.
 Allaf ME, Hoke A, Burnett AL.Erythropoietin promotes the recovery of erectile function following cavernous nerve injury.J Urol. 2005 Nov;174(5):2060-4.