By Theresa Tamkins
FRIDAY, March 13, 2009 (Health.com) — Ozone is considered pollution on ground level and an environmental protector when it’s in the earth’s atmosphere (that’s why a hole in the ozone is a bad thing).
Now it seems the molecule is a bit of a health paradox, too. A large new study released this week found that breathing in ozone-laden smog increases the risk of dying of respiratory diseases. But a second group of researchers also reported that injecting a small amount of ozone into a bad back may ease chronic pain caused by a herniated disc.
Injections of ozone and oxygen can shrink a disc that’s bulging out and putting pressure on surrounding nerves and tissue, according to Kieran Murphy, MD, who presented data on the technique at the Society of Interventional Radiology meeting in Chicago.
About 20,000 people in Europe have been treated with the ozone-injection technique, says Dr. Murphy, who presented data at the meeting on 8,000 patients treated in Italy and Austria. He says the success rate is 70 to 75 percent in terms of pain relief, and few back pain patients need more than one injection. (About 6 out of 50 in an early trial, he says).
Next page: How it works
“Ozone reacts with protein and breaks it down into carbon dioxide and water, so you get a subtle volume reduction [in the disc],” says Dr. Murphy, an interventional neuroradiologist and vice chair and chief of medical imaging at the University of Toronto. “It’s like letting a little bit of air out the tires of your car.”
About four out of five people suffer from back pain at some point; a herniated disc is a common cause. Herniated disc symptoms can include numbness or tingling in the buttocks or legs, or sciatica, a sharp, shooting pain from the buttocks down the back of the leg.
Dr Murphy has invented a small patented, pen-like device that can be used to produce ozone for the procedure, which differs from larger ozone-generating devices used in European trials, he says. Under X-ray guidance, a needle is inserted into the disc and the oxygen-ozone mixture (98 percent oxygen; 2 percent ozone) is injected. The device and technique aren’t available in the United States; both require Food and Drug Administration approval.
“I think it will help a lot of people avoid surgery but it will also help a lot of people who might get better over a year get better in say, six weeks,” says Dr. Murphy. “Not all people need surgery. In fact I think all doctors try not to operate on people, but I think what this will do is further reduce the number who will go on to need surgery.”
The new technique “could be a major advance for a very common problem,” says Brian Stainken, MD, president elect of the Society of Interventional Radiology.
Next page: Similar techniques are already available
However, Dr. Stainken notes that ozone injections have not been studied in placebo-controlled trials. That’s important because many people with back pain get better without injections or surgeries. Right now it’s impossible to say how many people who improved after the ozone-injection therapy would have gotten better without the injections.
“I think it’s something to watch,” says Dr. Stainken, who’s at the Roger Williams Medical Center in Providence, Rhode Island. The results look “strongly encouraging,” he says, but “clearly that doesn’t mean that we don’t need to do the necessary trials to prove that it’s important.”
However, Stuart Kahn, MD, director of Spine and Pain Rehabilitation at the Spine Institute at Beth Israel Medical Center in New York says he’s “an extreme skeptic of new technologies that are micro- or minimally invasive.”
There are already FDA-approved techniques that work in a similar fashion, he says, called the nucleoplasty and dekompressor techniques. They work “in a very small percentage of the [back-pain] population who have symptomatic sciatica from a disc bulge.” He says the techniques don’t “work well in patients who have a real herniation where the disc material is already extruded out of the center of the disc.”
Such techniques can have a 25 to 30 percent response rate, which is still “a pretty miraculous treatment” in patients who have failed all other therapies, including medication, physical therapy, home exercise programs, and epidural steroid injections. Such patients might otherwise need back surgery.
The ozone injections seem to be “a new twist on existing technology that’s pretty good for the right patient population and it might tweak something that already exists,” says Dr. Kahn. “I’d love to see a head-to-head study with existing technologies.”