Perioperative results following lumbar discectomy: comparison of minimally invasive discectomy and standard microdiscectomy

Object. Minimally invasive lumbar discectomy is a refinement of the standard open microsurgical discectomy technique. Proponents of the minimally invasive technique suggest that it improves patient outcome, shortens hospital stay, and decreases hospital costs. Despite these claims there is little support in the literature to justify the adoption of minimally invasive discectomy over standard open microsurgical discectomy. In the present study, the authors address some of these issues by comparing the short-term outcomes in patients who underwent first time, single-level lumbar discectomy at L3-4, L4-5, or L5-S1 using either a minimally invasive percutaneous, muscle splitting approach or a standard, open, muscle-stripping microsurgical approach. Methods. A retrospective chart review of 172 patients who had undergone a first-time, single-level lumbar discectomy at either L3-4, L4-5, or L5-S1 was performed. Perioperative results were assessed by comparing the following parameters between patients who had undergone minimally invasive discectomy and those who received standard open microsurgical discectomy: length of stay, operative time, estimated blood loss, rate of cerebrospinal fluid leak, post-anesthesia care unit narcotic use, need for a physical therapy consultation, and need for admission to the hospital. Results. Forty-nine patients underwent minimally invasive discectomy, and 123 patients underwent open microsurgical discectomy. At baseline the groups did differ significantly with respect to age, but did not differ with respect to height, weight, sex, body mass index, level of radiculopathy, side of radiculopathy, insurance status, or type of preoperative analgesic use. No statistically significant differences were identified in operative time, rate of cerebrospinal fluid leak, or need for a physical therapy consultation. Statistically significant differences were identified in length of stay, estimated blood loss, postanesthesia care unit narcotic use, and need for admission to the hospital. Conclusions. In this retrospective study, patients who underwent minimally invasive discectomy were found to have similiar perioperative results as those who underwent open microsurgical discectomy. The differences, although statistically significant, are of modest clinical significance.