A Systematic Review and Meta-Analysis of Nerve Gap Repair: Comparative Effectiveness of Allografts, Autografts, and Conduits

Abstract

Background: Ideal nerve repair involves tensionless direct repair, which may not be possible after resection. Bridging materials include nerve autograft, allograft, or conduit. This study aimed to perform a systematic literature review and meta-analysis to compare the meaningful recovery (MR) rates and postoperative complications following autograft, allograft, and conduit repairs in nerve gaps greater than 5 mm and less than 70 mm. A secondary aim was to perform a comparison of procedure costs. Methods: The search was conducted in MEDLINE from January of 1980 to March of 2020, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were included whether they reported nerve injury type, repair type, gap length, and outcomes for MR rates. Thirty-five studies with 1559 nerve repairs were identified. Results: Overall MR for sensory and motor function was not significantly different between autograft (n = 670) and allograft (n = 711) across both short and long gaps. However, MR rates for autograft (81.6%) and allograft (87.1%) repairs were significantly higher compared with conduits (62.2%) (P < 0.05) in sensory short gap repairs. Complication rates were comparable for autograft and allograft but higher for conduit with regard to pain. Analysis of costs showed that total costs for allograft repair were less than autograft in the inpatient setting and were comparable in the outpatient setting. Conclusions: Literature showed comparable rates of MR between autograft and allograft, regardless of gap length or nerve type. Furthermore, the rates of MR were lower in conduit repairs. In addition, the economic analysis performed demonstrates that allograft does not represent an increased economic burden compared with autograft.

Histologic Comparison of the Fascicular Area of Processed Nerve Allograft Versus Cabled Sural Nerve Autograft

“…16,27 These preclinical results may not be apparent clinically, as a meta-analysis published recently concluded that there were no significant meaningful recovery differences between autograft and allograft nerve reconstructions across short and long nerve gaps. 9,10 Although our current study did not investigate functional outcomes, future studies should consider the influence of fascicular area on functional outcomes. Although it is currently unknown if the differences in the regenerative area noted in this study lead to meaningful differences in clinical outcomes, previous basic scientific studies indicate that the available neural tissue (fascicular area) in the intercalary graft segment may influence potential nerve regeneration and distal reanimation.…”

Procedure Costs of Peripheral Nerve Graft Reconstruction

“…However, it is important to note that compared with the current study, the Lans study was conducted with Medicare fee-for-service hospital claims, and, in addition, multivariable analysis was not conducted to explore adjusted cost differences between the nerve repair types. 19 Not surprisingly, among inpatients and outpatients, mean implantable cost was significantly higher for allograft versus autograft nerve repair procedures but this was offset by savings in OR and R&B costs among allograft cases. A higher implantable cost was also observed among inpatient versus outpatient allograft nerve repair cases.…”

“…However, it is important to note that compared with the current study, the Lans study was conducted with Medicare fee-for-service hospital claims, and, in addition, multivariable analysis was not conducted to explore adjusted cost differences between the nerve repair types. 19 …”

“…Complication rates were comparable for autograft and allograft but higher for conduit with regard to pain. 19 …”

“…Complication rates were comparable for autograft and allograft but higher for conduit with regard to pain. 19 Surgeons also benefit from comparative cost data to help support their choice of treatment. Currently, the published literature on health care costs of allograft and autograft procedures is limited.…”