Minimally Invasive Techniques
To avoid open discectomy if conservative treatment fails, injections and numerous minimally invasive techniques have been and continue to be developed for treating lumbar disk disease.
Types of Minimally Invasive Techniques
Epidural corticosteroid injections have been controversial in the treatment of lumbar disk herniations, because controlled studies of their effectiveness have produced mixed results. Although methodologic protocols vary, most studies show that epidural injections do not provide long-term benefits in symptom reduction or functional improvement, nor do they reduce the need for surgery on a herniated disk. Their role in the management of disk herniations appears to be in the treatment of acute sciatic pain. Patients who received the most benefits from epidurals had a shorter duration (less than 1 year) of symptoms prior to injection.
Chemonucleolysis with chymopapain is another injection technique used for herniated lumbar disks. This treatment is infrequently performed today, because complications of neurotoxicity and anaphylaxis were reported in earlier studies. More recent evaluations of chemonucleolysis have shown it is a safe and effective technique in properly selected patients. One large study reported a success rate of 88% in patients with an acute disk herniation and sciatica. Patients in their teens and 20s whose symptom onset was less than 6 months earlier received the greatest benefit. A critical review of chemonucleolysis concluded that it is a beneficial therapy for some patients, but individuals receiving the technique are likely to need a repeat procedure; and discectomy results are poorer in patients who have previously received the injection than in those who have not.
Laser discectomy has been used to treat herniated disks since 1986. Nonprospective, nonrandomized studies reported successful outcomes of 50% to 89%. However, true efficacy is questionable because of the lack of quality-controlled trials comparing laser decompression to standard discectomy. Laser disk decompression, like percutaneous nucleotomy, is considered a blind technique, because the herniation and amount of material being removed is not directly visualized during the procedure. Patients with large herniations (occupying >50% of the spinal canal) and/or patients with migration or sequestration of free fragments are not candidates for blind, minimally invasive techniques.
Lumbar discectomy provides good to excellent outcomes for sciatica in 65% to 90% of treated patients. Outcome is better in patients who receive surgery within a year of symptom onset. After 1 year of symptoms, positive surgical outcomes drop precipitously to around 25%. Compared with nonoperative care, discectomy provides faster relief from sciatica during an acute attack, but long-term outcomes between patients treated surgically and those treated non operatively are often no different. Thus, the primary benefit of none mergent discectomy is to provide relief from sciatic pain when initial nonoperative care does not. The type of discectomy performed may play a role in surgical outcomes.