ObjectiveTo systematically review the efficacy and safety of percutaneous endoscopic lumbar discectomy (PELD) for L5/S1 disc herniation via transforaminal approach (TF-PELD) versus interlaminar approach (IL-PELD).MethodsPubMed, EMbase, The Cochrane Library, CBM, CNKI and WanFang Data databases were electronically searched to collect randomized controlled trials (RCTs) and the cohort studies of TF-PELD versus IL-PELD for L5/S1 disc herniation from inception to October 2017. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then, meta-analysis was performed by using RevMan 5.3 software.ResultsA total of 1 RCT and 7 cohort studies involving 414 patients were included. The results of meta-analysis indicated that: compared with IL-PELD group, TF-PELD group had longer operative time (MD=17.42, 95%CI 12.86 to 21.97, P<0.000 01) and more frequency of intraoperative fluoroscopy (MD=8.42, 95%CI 6.18 to 10.65,P<0.000 01), respectively. However, there were no significant differences between two groups in the post-operative visual analogue scale (MD=0.01, 95%CI –0.23 to 0.25,P=0.94), the post-operative Oswestry disability index (MD=–0.46, 95%CI –2.42 to 1.49, P=0.64), the excellent and good outcomes rate (RR=1.00, 95%CI 0.89 to 1.12, P=0.96), and the rate of complications (RR=0.73, 95%CI 0.45 to 1.18, P=0.20).ConclusionCurrent evidence shows that TF-PELD and IL-PELD are equally effective and safe for L5/S1 disc herniation, but IL-PELD is superior to TF-PELD in less operative time and less radiation exposure. Due to limited quality and quantity of the included studies, more high quality studies are needed to verify above conclusion.