Clinical outcome of microendoscopic posterior decompression for spinal stenosis associated with degenerative spondylolisthesis--minimum 2-year outcome of 37 patients.

A clear consensus for the optimal surgical treatment for spinal stenosis associated with degenerative spondylolisthesis (DS) has not appeared. In general, decompression and fusion are recommended. However, the symptoms of spinal stenosis are the main complaints in almost all patients with DS, and whether or not routine concomitant fusion is necessary in the surgical treatment for DS is still discussed controversially. The authors have treated almost all the patients with spinal stenosis associated with DS by microendoscopic posterior decompression (MEPD) procedures since 2001. In the present study, we examined the minimum 2-year outcome in 37 patients surgically treated with the MEPD procedures for spinal stenosis associated with DS. At the mean of 38 months after surgery, the overall results were excellent in 54% of the patients, good in 19%, fair in 13.5%, and poor in 13.5%, based on the Japanese Orthopedic Association lumbar score, a visual analogue scale, and the Roland-Morris disability questionnaire. Although the progression of spondylolisthesis and the increase of segmental sagittal motion after surgery were seen in 7 patients (19%), only one patient required secondary fusion during the follow-up period. A sufficient decompression with the preservation of the posterior structures of the spine was observed in almost the patients after surgery. In conclusion, the MEPD is a minimally invasive procedure developing a sufficient decompression with the preservation of the spinal stability. Thus, the MEPD is one of the useful procedures in the surgical treatment of spinal stenosis associated with DS. However, further follow-up studies should be performed to evaluate the long-term outcome for evaluation of the true validity of the MEPD for DS.

Surgical complications of microendoscopic procedures for lumbar spinal stenosis.

Microendoscopic discectomy (MED) is one of the minimally invasive endoscopic procedures for treating lumbar disc herniation. We have applied MED techniques to posterior decompression procedures for treating lumbar spinal stenosis (LSS). In the present study, we examined the surgical complications in 114 consecutive patients surgically treated with MED procedures for LSS. Intraoperative complications occurred in 9 patients. Six patients (5.3%) experienced a dural tear, and three (2.6%) had a fracture of an inferior facet. Early postoperative complications occurred in 13 patients. Twelve patients (10.5%) experienced transient neurological complications. The clinical outcomes at the mean 28-month follow-up were not affected by these surgical complications. Other major complications such as nerve injury and surgical site infection were not observed. Most of the complications occurred in the initial series of patients, and the incidence of complications decreased with an increase in the surgeon's experience and the application of several preventive measures against the complications. The surgeon should undergo training when MED techniques are applied in surgical treatment in order to recognize the specific complications associated with such procedures and apply preventive measures against these complications.