A systematic review of clinical and laboratory studies comparing vascularised versus non-vascularised nerve grafts in peripheral nerve reconstruction

Background: Peripheral nerve injuries (PNIs) are common, with complex defects posing a significant reconstructive challenge. Although vascularised (VNGs) and non-vascularised nerve grafts (NVNGs) are established treatment options, there is no comprehensive summary of the evidence supporting their clinical, electrophysiological, and histological outcomes. This review aims to systematically evaluate the clinical and laboratory literature comparing VNGs and NVNGs to inform future clinical practice and research.

Methods: This review was prospectively registered and reported according to PRISMA guidelines. PubMed, EMBASE, SCOPUS, and the Cochrane Register were systematically searched. Studies comparing VNGs and NVNGs in PNIs were included. Meta-analyses were performed for outcomes reported in ≥3 laboratory studies. Functional outcomes were synthesised by vote-counting based on direction of effect for clinical studies. Risk-of-bias was assessed using RoB2, ROBINS-I, and SYRCLE, and the certainty of evidence was evaluated using GRADE.

Results: Seven clinical and 34 laboratory studies were included. Of the clinical comparisons, 90% and 56% identified an effect on recovery of sensibility (p = 0.01) and motor function (p = 0.05), respectively, that favoured VNGs. Nine (of 13) separate meta-analyses of laboratory studies demonstrated reduced muscular atrophy, superior axonal regeneration, and remyelination in VNGs. VNGs eliminated the 3-day interval of ischaemia otherwise sustained by NVNGs. Overall, the quality of evidence was low.

Conclusion: This systematic review indicates that VNGs may offer some advantages over NVNGs in PNI reconstruction. However, due to the low quality of evidence, significant statistical heterogeneity, and clinical diversity of the included studies, these conclusions should be interpreted with caution. Further high-quality clinical trials are necessary to validate these findings.