I had part of a disc removed at L3,4 six months ago. Now I need a second operation to remove more of the disc material at the same level. Does this happen very often? I’m most unhappy about it.

Minimally invasive surgery to decompress the nerve pressed by a herniated or protruding disc is state-of-the-art now. The procedure is called a microdiscectomy. The surgeon makes a tiny incision in the skin and places an endoscope through the soft tissues to the affected area.

The endoscope is a rigid tube with a tiny TV camera on the end. It allows the surgeon to see the area being operated on without making a wide, open incision. Special surgical tools can be passed down through the tube as well. These tools are used to ream out the foraminal space (where the nerve root passes through the bone).

In many cases, removing only the loose fragments or protruding disc material has replaced complete removal of the disc. But the remaining disc can re-herniate requiring a second operation.

This can happen in any patient of any age from months to years after the first discectomy. Recurrence can occur at any lumbar spinal level but L45 and L5-S1 are the areas affected most often. Studies show the recurrence rate varies between five and 18 per cent. The reported rates may depend on how long patients are followed up after the primary (first) operation.