CHICAGO — Percutaneous disc decompression may resolve back pain and weakness caused by a herniated spinal disc, according to a study that compared the minimally invasive procedure with conservative therapy.
However, audience members who heard the study presented at the annual scientific meeting of the Radiological Society of North America said that several important weaknesses of the trial make it difficult to draw any conclusions about the long-term results of the intervention.
In patients who had herniation of an intervertebral disc, Dr. Dimitrios Filippiadis and his associates at Attikon University Hospital in Athens followed two groups of patients from January 2005 to January 2008 after they had received either conservative therapy (conservative treatment with analgesics, anti-inflammatory drugs, muscle relaxants, and physiotherapy for 6 weeks) or fluoroscopically guided percutaneous disc decompression.
Each group comprised 17 men and 14 women with a mean age of 36 years and a history of unsuccessful or incomplete medical treatment with conservative therapy. Each patient underwent magnetic resonance imaging to verify the disc herniation.
During the procedure, “a needle is inserted into the disc and 2–5 g of tissue are removed, diminishing pressure,” study co-author Dr. Alexios Kelekis said at a press conference during the meeting.
The intervention is not without risk, he pointed out. Potential complications include discitis, epidural abscess, reflex sympathetic dystrophy, nerve root injury, and injury to retroperitoneal structures.
Patients measured their pain with a 0–10 visual analog scale. Members of the conservative therapy group started at a mean of 6.87, and their pain declined to 0.9 within one month. The average pain score returned to about 4 by 12 and 24 months.
The percutaneous intervention group started with pain at a mean of 7.40, which declined to 2.96 at the end of one month. By 12 months, this group's pain was at 1.67, and at 24 months, 1.61.
“Initial effect was noted at 3 weeks, and sustained effect at 12 and 24 months. Only five patients—16%—had less than 4 points of pain relief,” said Dr. Kelekis, who is also with Attikon University Hospital.
When audience members asked for more detail about the method of disc decompression, Dr. Filippiadis said that “patients in this study were treated with different instruments available. We believe that all these procedures have similar results. It doesn't matter if you use ablation, laser, ozone, or alcohol gel. All of these procedures accelerate what nature would do in about 4–5 years.”
Dr. Nathalie Bureau, one of the session moderators, expressed concerns about the study.
“It's difficult to take out any conclusion [about the study]. There was a lot of bias in patient selection and methods, and the study didn't treat a very homogenous group of patients. The results were very good, but with those selection criteria, it's hard to derive any conclusions,” said Dr. Bureau of the University of Montreal. “The method wasn't very sound; there was no randomized controlled trial.”
Dr. Bureau also questioned the aggressive intervention. “Are we really proving that we're doing better than conservative treatment? Degenerative disc disease may be accelerated by [surgical intervention].
“It's an interesting study, but there are a lot of questions about the method, so I'm not sure the conclusions are very sound.”
Dr. Kelekis is a teaching consultant for ArthroCare Corp. and for DePuy Spine Inc., a Johnson & Johnson company. The other investigators had no relevant conflicts of interest to disclose.
The study was sponsored by the University of Athens.
The average pain score after 24 months was about 4 for conservative therapy and 1.61 for disc decompression.
Source DR. KELEKIS
This MRI shows a patient's spine prior to undergoing treatment for a herniated disc.
In this image, the spine is seen 1 year after the percutaneous disc decompression.
Source Images courtesy Radiological Society of North America