Microdiscectomy

Excerpt

Lumbar disc herniations (LDH) are a relatively common and early manifestation of degeneration of the lumbar spine. The reported incidence of LDH is 2% ~3% and the prevalence is around 12%. Prevalence of 4.8% among men and 2.5% among women above 35 years of age. The most common site of LDH is at L4–L5 and/or L5–S1. Surgery for LDH accounts for the most common indication for performing spinal surgery.

The first description of a disc herniation causing sciatica was made as early as 1934. For most patients, the radiculopathy associated with a herniated disc resolves nonoperatively, but for those in whom conservative management fails, surgical interventions can be a consideration. Treatment for such disc herniations has understandably evolved considerably as techniques continue to evolve. Chymopapain chemonucleolysis and automated percutaneous discectomy were two such techniques that have now fallen out of favor - chymopapain, for example, due to its risk of transverse myelitis. In the 1970s, the focus of surgical treatment shifted to a less invasive approach with decreased manipulation and trauma to the paraspinal musculature, ligamentum flavum, and affected nerve root.

The first documented experience with the micro-lumbar discectomy (MLD) technique using an operating microscope was in 1977, independently by both Yasargil and Caspar in Europe. In 1978, Williams was the first to popularize and publish the technique in the United States. Since then, studies have demonstrated the safety and efficacy of microdiscectomy compared to open discectomy and have published outcomes of decreased morbidity, quicker recovery, shorter hospital length of stay, and no significant difference with regard to long-term reoperation rates.

Today, microdiscectomy with its smaller incision, less traumatic approach, and better visualization of the operative field than standard open discectomy is considered the gold standard for removing most lumbar disc herniations. Because of its collinear light and magnification, an operating microscope is preferred; however, magnifying loupes and a headlight may also be used. Most procedures are now done in the outpatient setting.

The major advantage of MLD compared to open/standard (SD) is the minimal trauma to the multifidus and reduced risk of post-operative peridural fibrosis.