This procedure was initially described by NuVasive, Inc., and many companies have since tried to improve on the initial technique
The XLIF procedure is a minimally invasive surgical technique that allows an anterior spinal fusion of the lumbar or thoracic spine avoiding the anterior approach of the spine.
This procedure is done through a small incision on the side of the flank. The spine is exposed through the Psoas muscle (see animation below) down to the disc. In order to avoid injuring a nerve, while progressing through the muscle, a monitoring system is used, measuring constantly the distance of the instrument from the nerve. The advantage of this procedure is to reduce the operating time, reduce the scar, reduce the blood loss, and reduce the postoperative pain. The recovery is much faster and the hospital stay is reduced.
There is an additional advantage for patients who have already had anterior spinal surgery and who have developed scar tissue around the spine. On these patients, the anterior approach is difficult and potentially dangerous due to the adherence of the abdominal vessels. The conditions commonly treated with this technique are disc degeneration, spondylolisthesis, and degenerative scoliosis. With this approach, the disc can be cleaned from all debris and a fusion can be done by the insertion of a spacer called a "cage," packed with bone or bone substitute. Using the same minimally-invasive approach one can also place a plate which will hold the cage in place and fixed with two screws.
We can now perform this surgery through a one inch incision whereas before it was necessary to make a complete opening of the abdomen.
Below is an animation of the XLIF technique.