Nerve decompressive surgery of the lower limbs for diabetic peripheral neuropathy: a systematic review and meta-analysis.

Objective: There is no consensus on the efficacy and safety of nerve decompressive surgery of lower limbs (NDSLL) for diabetic peripheral neuropathy (DPN). This systematic review aims to evaluate the efficacy and safety of NDSLL compared with no surgery in DPN by analyzing relevant evidence from randomized controlled trials (RCTs). Methods: Using PubMed, Embase, Cochrane Library, ClinicalTrials.org and Chictr.org.cn, a systemic literature review was performed in accordance with the Preferred Reporting Items for Systemic Reviews and Meta-Analyses statement (CRD42021295459). Results: Screening filtered 793 studies to 7 trials containing 207 patients. Only two of the eight registered RCTs have been published (25% publication rate), indicating substantial publication bias. Risk of bias was high across most trials, with particular concerns regarding: lack of participant and personnel blinding; absence of sham surgery controls in 6/7 trials; incomplete outcome data; and selective reporting. These methodological flaws likely contribute to overestimation of treatment effects. Compared to no surgery, NDSLL was associated with VAS reduction at postoperative month (POM) 6 (WMD: -2.77, 95% CI: -3.84 to -1.69) and POM 12 (WMD: -2.41, 95% CI: -4.52 to -0.29). However, wide confidence intervals-particularly at 12 months-and high bias risk limit confidence in these estimates. No RCT evidence supported improvement in quality of life, nerve conduction velocity, balance, ulcer healing, or sensation. Among 113 NDSLL patients, 27 (23.9%) experienced wound-related complications (infection, dehiscence, edema, hematoma); no complications were reported in no-surgery groups. Conclusions: NDSLL may offer pain relief in selected DPN patients, but the current evidence is derived from a small number of high-bias RCTs with substantial publication bias, considerable methodological heterogeneity, and a notable complication rate. The true treatment effect may be substantially smaller than pooled estimates suggest. The absence of demonstrable benefit on quality of life, nerve function, balance, ulcer healing, or sensation constrains clinical utility. NDSLL should remain an investigational procedure pending adequately powered, sham-controlled, multicenter RCTs with standardized outcome measures. More high-quality research is urgently needed before NDSLL can be recommended as standard treatment. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD42021295459, PROSPERO CRD42021295459.