In a randomized, comparative study of long-term outcomes after surgery for lumbar stenosis, limited decompression procedures resulted in a highly significant reduction of symptoms, according to results presented here at the American Association of Neurological Surgeons 2010 Annual Meeting.

Long-term outcomes were equivalent for unilateral laminotomy and for laminectomy, but the best results on several measures were obtained with bilateral laminotomy.

Lead study author Claudius Thomé, MD, of the Neurosurgery Clinic at the University of Heidelberg in Mannheim, Germany, said that less invasive procedures for decompression of lumbar stenosis are being used with increasing frequency to minimize tissue damage.

"There may not be a need to do the long laminectomies that we have been doing for many years because the target area actually is only at the level of the bulging...ligament," he said.

Substantial Benefits

Although studies with small numbers of patients have shown substantial benefits but more complications using less invasive procedures, randomized, prospective, comparative studies with long-term outcomes have not existed. So the researchers thought it was reasonable in this study to compare long-term outcomes for bilateral laminotomy (group B), laminectomy with facet sparing (group L), and unilateral laminotomy with contralateral undercutting (group U).

They randomized to the 3 treatment groups 120 consecutive patients (mean ± SD age, 68 ± 9 years) with 207 levels of lumbar stenosis (mostly L3-L4 or L4-L5) but without herniated discs or instability. At 8.8 ± 0.9 years after operation, 78 patients (94% of patients still alive) were available for follow-up.

At that time, group B patients tended to have less residual pain as assessed on a visual analog scale of 0 to 10 (3.3 ± 2.8 vs 4.9 ± 2.9 [L] vs 5.4 ± 3.4 [U], for all groups; P < .01 compared with their preoperative pain).

Walking distance increased the most for group B (to 3169 ± 4153 m vs 1568 ± 2349 m [L] vs 2355 ± 3980 m [U]). The differences between groups were not statistically significant (but P < .01 vs the preoperative conditions for all groups).

"The patients in the laminectomy group and also in the unilateral group seemed to have more low back pain, particularly when walking, in comparison to the bilateral group," Dr. Thomé noted. "The number of complications in contrast to previous studies actually showed that laminectomy had the most complications compared with the other groups."

Patient satisfaction was significantly greater in group B (89%) compared with group L (61%) or group U (62%). Using the 36-item Short Form Health Survey to assess functional health and well-being, the researchers reported that some subscales showed a significant difference in favor of group B. Additional operations were necessary in 7% of group B patients, 43% of group L patients (P < .05 vs group B), and in 33% of group U patients (P < .05 vs group B).

"We now only do bilateral approaches."

In summary, "less invasive laminotomy decompression techniques dramatically and also durably...reduced symptoms and improved the quality of life. The outcome of unilateral...decompression was, in our hands, comparable and nonsuperior to laminectomy, and the bilateral laminotomy approach demonstrated a significant superiority in most outcome parameters and long-term follow-up of nine years," Dr. Thomé concluded. "We now only do bilateral approaches."

"Stellar Work"

Charles Branch, MD, professor and chairman of neurosurgery at Wake Forest University Baptist Medical Center in Winston-Salem, North Carolina, reviewed the study and said, "This is truly stellar work to help bolster the evidence base for surgical spine care." He cited the prospective, randomized method and the short- and long-term outcomes data generated using standardized metrics.

Dr. Branch noted that all the decompression techniques produced beneficial results but said bilateral laminotomy was superior in patient satisfaction compared with the other 2 techniques.

Unilateral laminotomy appeared not to be much better than "big laminectomy," he said. "What we don't get from this study is what the quality of the radiographic decompression is." Such a finding may not be as important as the clinical outcome since surgeons treat "patients and not x-rays," he added. "But certainly we would want to know whether the difference in outcomes really is due to the adequacy of decompression."

In summary, Dr. Branch said the study "really demonstrates satisfactory outcome with a variety of approaches [and] apparent benefit with the less morbid or less invasive approach. I think this is a very important contribution to our literature."

Dr. Thomé reported grant/research support from Intrinsic Therapeutics Inc and Signus Medical and is a consultant to Signus Medical. Dr. Branch has disclosed no relevant financial relationships.

American Association of Neurological Surgeons (AANS) 2010 Annual Meeting: Abstract 806. Presented May 5, 2010.

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