Bladder Pacemaker Helps Restore Bladder Control
Just as a cardiac pacemaker helps maintain a steady heartbeat, a new bladder pacemaker helps men and women with debilitating bladder problems regain control of this vital function, according to urologists at Stanford and UCSF who pioneered the technology.
The implantable bladder pacemaker delivers a painless electrical stimulus to the nerve fibers that regulate the muscle of the bladder. This enables patients to control urine storage and release, said Emil Tanagho, a UCSF professor of urology whose early work with paraplegics and quadriplegics led to the development of the device.
Tanagho and Rodney Anderson, a Stanford professor of urology, are among the three physicians in California - and the only two in Northern California -currently implanting the device, which was approved by the FDA in September 1997.
The new pacemaker may benefit patients suffering from urge incontinence. It could also help people with severe bladder problems associated with multiple sclerosis, Parkinson's disease, interstitial cystitis or pelvic pain produced by overactive pelvic muscles.
The pacemaker, about two inches in diameter and one-fourth inch thick, is encased in a stainless steel frame and is surgically implanted under the skin in the lower abdomen. It carries a lead wire, containing four platinum electrodes, that is threaded to a site within the sacral canal, near the sacral nerves at the base of the spine.
Once installed, the device is externally programmed by the physician to send electrical impulses to the nerves. This signals the bladder and pelvic muscles to contract or relax as urine is stored or eliminated. Patients can also regulate the device, within certain set limits, by turning it up or down.
In clinical trials in the United States, Canada and Europe, the device reduced the number of leaking episodes among 74 percent of the 458 patients within six months after implantation. Almost half of the patients remained completely dry. The most common problems associated with the device were discomfort at the pacemaker site caused by the presence of the device, movement of the lead wire, infection and skin irritation. But all of these were mild and infrequent, the studies found.
When the stimulation is on, patients usually report feeling a kind of tugging sensation and may experience a vibration or an electric tingling, but over time they may forget the device is in place, Anderson said.
The device is a much-needed addition to the medical arsenal, Anderson said, because in the past physicians have had few options to offer patients with severe bladder control problems. Although few physicians currently have experience in installing the new device, Tanagho said he expects the pacemaker to gain wider availability over time as more urologists receive the specialized training required for its implantation and use.
The original concept for the device grew out of Tanagho's research in the 1970s on methods for managing the bladder in patients with spinal cord injuries.
In the late 1980s, Tanagho directed clinical trials on the first-generation bladder pacemaker, recruiting Anderson to participate. UCSF now holds the patent on the technology, which is licensed to the Minneapolis-based Medtronic Inc. The company manufactures the device under the trade name Interstim.
The new bladder pacemaker is attached to a lead wire that is threaded to a site within the sacral canal at the base of the spine. The pacemaker can be externally programmed to deliver an electrical stimulus to the sacral nerves, which regulate bladder function. This enables patients to control urine storage and release.