The safety and efficacy of minimally invasive discectomy: a meta-analysis of prospective randomised controlled trials

Purpose The objective of this study was to compare the safety and efficacy of minimally invasive discectomy (MID) with standard discectomy (SD) and determine whether the use of the MID technique could decrease the recurrence of lumbar disc herniation (LDH) after the surgery. Methods In February 2014, a comprehensive search was performed in PubMed, EMBASE, Web of Science, Cochrane Library and the Chinese Biological Medicine Database. Only randomised controlled trials (RCT) that compared MID with SD for the surgical management of LDH were included. These trials were carefully picked out following the inclusion and exclusion criteria. Using the Cochrane Collaboration guidelines, two authors independently extracted data and assessed these trials' quality. The age of the patients, size of incision, surgical time, blood loss, visual analogue scale (VAS) score after the surgery, hospital stay, disc herniation recurrence, X-ray exposure and surgical costs in these studies were abstracted and synthesised by a meta-analysis with RevMan 5.2.0 software, and the main results (VAS score after the surgery and disc herniation recurrence) of publication bias were examined by Stata 12.0. Results Overall, 16 trials involving 2,139 patients meeting our criteria were included and analysed. Comparing MID and SD, the former was more likely to increase disc herniation recurrence [relative risk (RR) = 1.95, 95 % confidence interval (CI) 1.19-3.19, p = 0.008], and it involved a smaller size of incision [mean difference (MD) = -1.91, 95 % CI -3.33 to -0.50, p = 0.008], shorter hospital stay, longer operating time (MD = 11.03, 95 %C I 6.62-15.44, p < 0.00001) and less blood loss (MD = -13.56, 95 % CI -22.26 to -4.87, p = 0.002), while no statistical difference appeared with regard to the age of the patients, VAS score after the surgery, X-ray exposure, hospital stay and surgical costs. Conclusions Based on available evidence, MID results in less suffering for patients during the hospital course with a similar clinical efficacy compared to SD. This makes MID a promising procedure for patients with LDH; however, to popularise it greater effort is required to reduce disc herniation recurrence.