Background: Lumbar spinal stenosis is a common cause of radicular and generalized back pain among older adults. Endoscopic minimally invasive surgery, in contrast to open decompression, may provide the opportunity for a less invasive surgical intervention. Thus, the purpose of this study is to evaluate the safety (operative complications, estimated blood loss, operative room time) and effectiveness (pre- versus postoperative level of disability and pain severity) of minimally invasive surgery using endoscopic laminotomy and foraminotomy among a large sample of patients with lumbar spinal stenosis.

Methods: This study is composed of 320 consecutive patients with lumbar spinal stenosis who underwent posterior lumbar laminotomy and foraminotomy between 2008 and 2011. Outcome measures consisted of perioperative complications, estimated blood loss, operative room time, level of disability, and pain severity. Pain severity and level of disability were prospectively analyzed to an average of 18 months (12-36 months) post-surgery.

Results: There was an average estimated blood loss of 39.3 cc and a mean operative room time of 74 min. Seven patients experienced minor operative complications. All patients were discharged the same day as surgery and reported a significantly lower level of disability (p = 0.00) and pain severity (p = 0.00) postoperative compared to preoperative.

Conclusions: Minimally invasive surgery using endoscopy for the treatment of lumbar spinal stenosis has a short operative time, a low operative complication rate, and minimal estimated blood loss. This study also indicates that MIS for the treatment of LSS can significantly reduce pain and disability level. Thus, minimally invasive surgery using endoscopic laminotomy and foraminotomy appears to be a safe and effective alternative surgical treatment for open decompression surgery in adult patients with lumbar spinal stenosis.