PITTSBURGH, January 20, 1999 — Orthopaedic spine surgeons at the University of Pittsburgh Medical Center (UPMC) are seeing good results with a new minimally invasive outpatient surgery that significantly reduces the pain and recovery time associated with lower back herniated disc surgery.
During the past year, the surgeons have used the MicroEndoscopic Discectomy System (MED™) to surgically treat herniated discs in 17 patients, all with good-to-excellent results. The UPMC surgeons are the first in the Pittsburgh region to use the MED system, and UPMC’s department of orthopaedic surgery is now part of a multi-center study, organized and partially funded by the National Spine Network (NSN), to further evaluate this technique, which represents the newest generation of minimally invasive endoscopic disc surgery.
"Herniated or bulging discs are among the most common and painful of all serious back problems. Nationwide each year, about 250,000 people undergo surgery to relieve the condition," said James Kang, M.D., assistant professor of orthopaedic surgery and neurosurgery and a principal investigator for the NSN study.
Each disc acts as a flexible shock absorber between the bony vertebrae of the spinal column. When a lower back disc ruptures or herniates, it protrudes into the spinal canal compressing the spinal nerves and may cause severe back and leg pain. Patients often will develop sciatica, pain radiating from the back down to the foot, which can be extremely disabling.
A majority of patients who develop disc herniations can be effectively treated by non-operative measures, such as physical therapy, anti-inflammatory medicines and steroids. However, 10 to 20 percent of patients develop progressive disabling pain resistant to conservative treatment, and these patients become candidates for surgical discectomy treatment. Traditional open discectomy surgery usually involves an incision up to four inches, a one-to-two-day hospital stay and a six-to eight-week recovery period. As an improvement to that, in the recent past, surgeons have been able to use an operative microscope to make the incision smaller—one to two inches. This procedure is called a micro-discectomy.
Now the new, more advanced micro-endoscopic discectomy (MED system) allows the surgeon to fully remove herniated disc fragments and relieve nerve compression in the lower spine through an even smaller incision measuring less than an inch long, according to Dr. Kang. The MED surgery involves a single half-inch incision in the back through which a tube slightly larger than a fountain pen is inserted. The tube encases micro-surgical instruments used to remove the disc herniation. Surgeons then use advanced optical systems to view the endoscopic image on a video monitor while they work.
"For patients, the MED procedure is the least invasive option. It is less painful and less expensive with a shorter and easier recovery period," said William Donaldson, M.D., associate professor of orthopaedic surgery and neurosurgery, who also uses the MED system. "Patients go home the same day and are back to work in about 7 to 10 days." This is generally true because there is less muscular trauma with the MED procedure compared to the traditional open discectomy or micro-discectomy surgery.
Currently, this new MED procedure is available to most patients with herniated discs in the lumbar spine, especially those who have failed all conservative treatment measures, according to Dr. Kang, who also is the co-director of spinal research at the UPMC’s Musculoskeletal Research Center. The procedure is not indicated yet for patients with degenerative spinal stenosis, progressive narrowing of the spinal canal due to large bone spurs, or structural abnormalities.
This surgical technique is being rapidly advanced. "The expected improvements in fiber optics and better endoscopic instrumentation will make MED an easier procedure for most spinal surgeons," Dr. Kang said.
The 17 patients who have undergone the MED procedure within the past year have all done very well without any major complications. Their return-to-work time has been dramatically decreased—three patients have returned to work within one week.
"Although initially very promising, we are still evaluating this technique very carefully and trying to assess the efficacy in relation to the more traditional types of disc surgery," said Dr. Donaldson.
The NSN study of the MED system is part of a multi-center study involving approximately 25 major medical centers in the United States. Each center will prospectively enroll 15-20 consecutive patients for this study to critically evaluate short- and long-term patient outcomes, including functional status, return-to-work rates, and other variables involved in lumbar discectomy surgery. Drs. Kang and Donaldson both said they believe the new MED surgery will show improved and earlier return-to-normal function in most patients.
The NSN is a not-for-profit organization representing 26 centers of excellence nationwide dedicated to the appropriate, multidisciplinary management of spine care. The spine surgeons in UPMC’s department of orthopaedic surgery have been active participating members since 1994.