Ozone Nucleolysis for Slipped Disc Management

Since disc prolapse was first diagnosed by Dandy and subsequently by Mixter and Barr it has been implicated as one of the important cause of low back pain radiating to limbs. Apart from conservative therapy all other forms of treatment aim at decompressing the nerve roots. These can be done by taking the disc out by surgery or by decompressing the foremen and disc by different interventions. The various treatment options have confused clinicians due to significant failure rate associated with different kinds of surgeries as well as with different interventions.

Outcome studies of lumber disc surgeries document a success rate between 49% to 95% and re-operation after lumber disc surgeries ranging from 4% to 15%. Reasons for this failure are: 1) dural fibrosis, 2) arachnoidal adhesions, 3) muscle & facial fibrosis 4) mechanical instability resulting from the partial removal of bony and ligamentous structures required for surgical exposure and decompression 5) presence of neuropathy. There has been surge of interest in search of safer alternative method of decompressing the nerve roots maintaining the structural stability. Epidural steroid injection, transformational epidural decompressions has a high success rate (up to 85%) but chances of recurrences are there specially if these interventions are done at later stage. Chemonucleolysis using chymopa pain has also high success rate (80%) with low recurrences but not popular owing to the chances of anaphylaxis following intradiscal chymopa pain injection. Injection of ozone for discogenic radiculopathy (low back pain with radiation to legs) has developed as an alternative to chemonucleolysis and disc surgery owing to its high success rate, less invasiveness, fewer chances of recurrences and remarkably fewer side effects.

Muto suggested intradiscal injection of ozone for disc hernia in 1998 under CT guidance. Leonardo popularized fluoroscope guided ozone injection into the inter vertebral disc. After that, successful outcome has been reported from various European centers. It is very important to note from those reports that complications are remarkably few. Not a single serious life-threatening complication was found even after 30,000 cases of Ozonucleolysis, which stresses the safety of these procedures.

How ozone acts? The action of ozone is due to the active oxygen atom liberated from breaking down of ozone molecule. When ozone is injected into the disc the active oxygen atom called the singlet oxygen or the free radicle attaches with the proteo-glycan bridges in the jelly-like material or nucleus pulposus. They are broken down and they no longer capable of holding water. As a result disc shrinks and mummified and there is decompression of nerve roots. It is almost equivalent to surgical discectomy and so the procedure is called ozone discectomy or ozonucleolysis. Besides, it has an anti-inflammatory action due to inhibitions of formation of inflammation producing substances and tissue oxygenation is increased due to increased 2,3 diphosphoglycerate level in the red blood cells. All these leads to decompression of nerve roots, decreased inflammation of nerve roots, increased oxygenation to the diseased tissue for repair work.

It is done usually under local anaesthesia. Light general anaesthesia may be administered in apprehensive patients only. The patient is taken to the operation theater lying on prone position. Very fine needle is introduced into the diseased disc under fluoroscopic guidance. The position of needle tip may be confirmed by injecting some small amount of radio-opaque dye. Then some 3-5 cc of oxygen-ozone mixture (at a concentration of 29 microgram/ml.) is injected into the disc. Ozone at this concentration is not all harmful for the surrounded tissue. So if ozone spreads to the surrounded tissues including spinal cord causes no harm. Ozone molecule is not stable. It has a half-life of 20 minutes only. So, within 20 minutes only half of the original ozone remains, the rest becomes oxygen. Increase in temperature decreases its half-life. For injection it is always freshly prepared on site (from an ozone generator) for immediate administration. Only Ozone resistant syringes can be used for injecting it. While needle with the syringe is taken out some amount of oxygen-ozone mixture is also injected into the para spinal muscle and para radicular soft tissue to reduce nerve root inflammation and increased oxygenation of the para-spinal muscles. Some 15 to 30 minutes is required to perform the total procedure depending on the experience of the interventionist.

There are few conditions when this procedure should not be performed. They are active bleeding from any site, pregnancy, G6PD deficiency, active hyperthyroidism, loss of control of urination & defecation, and progressive sensory & motor loss (paralysis).

Ozonucleolysis or ozone discectomy has a success rate of about 80%. On the other hand surgical discectomy has much higher side effects compared to remarkably few side effects of ozone discectomy. Ozone discectomy is usually a day care procedure and general anaesthesia is not usually required. Total cost of the procedure is much less than that of surgical discectomy. All these facts have made this procedure very popular at European countries. It is also gaining popularity in our country due to low cost, less hospital stay, no post-operative discomfort and morbidity and very few side effects.