New minimally invasive technique may be useful to decompress lumbar nerve roots

Using the Gill criteria, three patients showed excellent results and four had good outcomes.

By Gina Brockenbrough

Using a new endoscopic technique to treat patients with spondylosis-induced lumbar nerve root compression shows promising results, according to researchers from Japan.

“Although spinal fusion is the gold standard to treat spondylolysis and spondylolisthesis, decompression without fusion can be effective procedure for certain patients,” Koichi Sairyo, MD, PhD, an author of the study toldOrthopedics Today. “Surgeons should understand the pathology of the symptom for the patients. Not all patients need fusion surgery.”

The research appeared in the Journal of Neurosurgery.

Scott D. Boden, MD
Scott D. Boden

Orthopedics Today Spine Section Editor Scott D. Boden, MD, said that while minimal incision decompression techniques have the potential to improve patient outcomes, such results should be properly proven

“I believe that such techniques, while exciting, have not yet found their way into broad use because a meaningful objective improvement in patient outcomes has yet to be consistently documented that would be sufficient to justify the increased cost of disposables and increased learning curve for the surgeon,” Boden told Orthopedics Today. “Instead, some of the minimally invasive decompression techniques have served as marketing tactics to attract patients to practices.”

He added, “The possibility of decompression without fusion for spondylolisthesis patients with only radicular leg pain as proposed by Sairyo is attractive and the key will be whether good results are maintained with long term follow up.”

Endoscopic decompression

finger-width incision
For the procedure, about a one-finger width skin incision is needed to insert the endoscope.

Images: Sairyo K

Sairyo and his colleagues studied seven patients who were older than 40 years old and underwent endoscopic decompression surgery to treat a total of 10 vertebral levels. Preoperatively, the patients had radiculopathy without low back pain and no evidence of spinal instability on dynamic radiographs. Four patients had no evidence of subluxation, and three patients were categorized as having Meyerding grade I slippage. The patients had a mean follow-up of 11.7 months.

The investigators found no intra- or postoperative complications. Using the Gill criteria, they discovered that three patients had excellent clinical outcomes and four patients had good results. They also found that all of the patients reported a decrease or disappearance of leg pain and returned to daily activities within 3 weeks. Radiographs at final follow-up also revealed no increase in slippage in any patient.


Sairyo noted that the technique is minimally invasive. “The skin incision is about 18 mm and the muscular damage is also minimal [because you are] using a tubular retractor,” he said.

After making the skin incision, surgeons performed fenestration to identify the impacted nerve root. They then removed the proximal stump of the ragged edge of the lesion and cleared away the fibrocartilage mass compressing the nerve root. They used a CT scan to verify that the proximal stump of the ragged edge of the lesion was removed.

“To decide the indication and to understand the exact pathology causing the symptom is the most challenging part,” Sairyo said. “If the pain is from the disc, this procedure is not effective. They may need fusion.”

decompressed L5 nerve root
This endoscopic view shows that the L5 nerve root is completely decompressed.

Patient indications

The procedure is indicated for elderly patients with minimal back pain and radiculopathy caused by a pseudoarthrotic site of spondylolysis — the ragged edge. Patients should also have no evidence of instability on radiographs, Sairyo said.

He noted that there is a learning curve for using the technique.

hooked-shaped osteophyte
This preoperative CT scan shows that the hooked-shaped osteophyte (encircled) has entrapped the nerve root.
post osteophyte removal
Surgeons removed the osteophyte as seen in this postoperative scan of the same patient.

“Before starting this technique, one must get used to the microendoscopic discectomy technique to treat herniated nucleus pulposus [and perform] at least 50 cases,” Sairyo said.

He added, “This technique is possible with a surgical microscope. The minimally invasive microscopic surgery using a tubular retractor is also effective.”

For more information:

  • Scott D. Boden, MD, is director of Emory University Spine Center. He can be reached at 59 Executive Park South, Suite 3000, Atlanta, GA 30329; 404-778-7143; e-mail:scott.boden@emoryhealthcare.org. He is a consultant to Medtronic, receives royalties from Medtronic and Osteotech, and his center receives various funding from Medtronic, Synthes, National Institutes of Health, Linvatec, Johnson & Johnson, DePuy, a Johnson & Johnson company, and Wright Medical Technology.
  • Koichi Sairyo, MD, PhD, can be reached at the Department of Orthopedics, Institute of Health Biosciences, The University of Tokushima Graduate School 3-18-15, Kuramoto, Tokushima 770-8503, Japan; e-mail: sairyokun@hotmail.com or Sairyo@clin.med.tokushima-u.ac.jp. He has no direct financial interest in any products or companies mentioned in this article.


  • Sairyo K, Katoh S, Sakamaki T, et al. A new endoscopic technique to decompress lumbar nerve roots affected by spondylolysis. J Neurosurg. 2003; 98 (Suppl 3): 290-293.

Source: http://www.orthosupersite.com/view.asp?rID=60612


Josh Sandberg

Josh Sandberg is the President of Ortho Spine Partners and Partner for The De Angelis Group. He also serves as Co-Founder and Editor of OrthoSpineNews.

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