Open Versus Minimally Invasive Surgery for Extraforaminal Lumbar Disk Herniation: A Systematic Review and Meta-Analysis

INTRODUCTION: Extraforaminal disk herniation (EDH) accounts for 3%-11% of all disk herniations. Despite the heterogeneity of spinal procedures, there is a paucity of literature comparing the outcomes from different surgical approaches. METHODS: We performed a systematic review and meta-analysis of available literature on EDHs. We compared patients undergoing open surgery (OS) with those undergoing minimally invasive surgery (MIS) approaches, including tubular microscopic, percutaneous endoscopic, and microendoscopic. RESULTS: A total of 41 studies with 1813 patients (1239 OS, 574 MIS) were included our analysis. The MIS group showed no significant difference from OS group in the incidence of complications (MIS: 0.01 vs. OS: 0.01, P = 0.971) or reoperation (OS: 0.04, MIS: 0.03; P = 0.382). There was an increased incidence of poor patient satisfaction according to the Macnab criteria for the OS group compared with the MIS group, but the difference was not statistically significant (OS: 0.14 vs. MIS: 0.06; P = 0.237). The OS group had greater estimated blood loss (mean difference = MD]: 38.6 mL), slightly longer operation time (MD: 12.2 minutes), longer hospital stay (MD: 30.3 hours), and longer return to work time (MD: 3.3 weeks). Tubular microscopic procedures had a lower incidence of reoperation than both percutaneous endoscopic (0.01 vs. 0.06, P = 0.01) and microendoscopic procedures (0.01 vs. 0.05, P = 0.03). CONCLUSIONS: Minimally invasive procedures for EDHs are associated with a similar incidence of complications and reoperation but lower estimated blood loss, shorter operative time, shorter hospital stay, and faster return to work time compared to OS. Tubular microscopic have the lowest reoperation rate of MIS procedures.