Polyethylene glycol-mediated nerve repair may accelerate early recovery in patients with distal forearm nerve injuries

1. Polyethylene glycol-mediated neurorrhaphy was associated with early sensory recovery and lower pain scores in the early postoperative period compared to standard repair in Sunderland V median and ulnar nerve injuries.

2. Patients in the polyethylene glycol nerve repair group demonstrated significantly higher sensory, motor, and Michigan Hand Questionnaire scores.

Evidence Rating Level: 1 (Excellent)

Study Rundown: Surgical repair of upper extremity peripheral nerve injuries often results in incomplete functional recovery due to Wallerian degeneration at the level of the axon. Polyethylene glycol (PEG), an osmotic laxative and fusogen, is theorized to promote early axonal fusion, restoring the continuity of electrical conduction in injured regions. This study compared PEG-mediated neurorrhaphy to the standard non-PEG neurorrhaphy in patients with acute Sunderland V median and ulnar nerve injuries. Adults presenting within 72 hours of traumatic, complete transection injuries of the median or ulnar nerve were randomized to PEG-assisted or conventional non-PEG repair, with sensory and motor outcomes assessed using objective measures including the Medical Research Council Classification (MRCC), two-point discrimination, and monofilament testing. Patient-reported function was also assessed using the Michigan Hand Questionnaire, a validated measure of hand function and quality of life. Within the first 22 days postoperatively, PEG-treated patients achieved higher levels of sensory and motor recovery, whereas controls demonstrated lower functional status. Early outcomes also revealed significantly improved sensory thresholds and reduced pain in the PEG group. Over the 390-day follow-up period, PEG-mediated repair afforded higher estimated sensory and motor recovery and improved patient-reported outcomes. Although motor-specific data were limited, trends favored earlier recovery in the PEG cohort. No PEG-related adverse events were identified. These findings suggest that PEG may accelerate early axonal continuity and functional recovery after distal forearm nerve injury. Strengths of this study included its randomized, double-blind design and the use of both objective clinical metrics and patient-reported outcomes. Limitations included a small sample size, substantial loss to follow-up, and differences in follow-up duration between groups, which weakened longitudinal comparisons and introduced potential attrition bias. Overall, the study provided promising early evidence supporting PEG-mediated nerve repair, but the findings require validation in larger trials with consistent long-term follow-up.

Click to read the study in JACS

Relevant Reading: Polyethylene Glycol Fusion of Nerve Injuries: Review of the Technique and Clinical Applicability

In-Depth [randomized controlled trial]: This double-blind randomized clinical trial enrolled adults 18 to 75 years old presenting to the emergency department or hand clinics within 72 hours of acute Sunderland V median or ulnar nerve transection between 2021 and 2025. Patients were randomized to PEG-mediated neurorrhaphy (n = 8) or standard neurorrhaphy (n = 5). Outcomes were evaluated by blinded assessors across serial postoperative visits over 13 months. Primary outcomes included objective sensory and motor recovery, as assessed by the Medical Research Council Classification (MRCC), two-point discrimination, and Semmes-Weinstein monofilament testing. Patient-reported function was also recorded using the Michigan Hand Questionnaire (MHQ). Within the first 21 days postoperatively, PEG-treated patients demonstrated significantly improved sensory recovery, with tighter two-point discrimination (16.6 vs. 21.7, P = .008), improved monofilament testing scores (7.31 vs. 5.82, P = .003), and higher MRCC sensory grades (P = .02). PEG-treated patients also achieved recovery of protective sensation with improved touch discrimination and motor recovery sufficient for active movement against gravity, while controls were limited to partial sensory recovery and weaker motor function. PEG-treated patients also reported lower pain scores in the early postoperative period (10.7 vs. 14.5, P < .05). Across follow-up of 390 days, PEG-treated patients demonstrated higher sensory (MRCC +1.27, P = .039) and motor (MRCC +1.13, P = .013) scores, better sensory thresholds with two-point discrimination (-6.68, P = .032) and monofilament testing (-1.89, P = .013), and higher MHQ functional scores (+3.38, P = .046). No PEG-related adverse events were reported, although one patient in the control group sustained a fall unrelated to the repair technique and was therefore removed from subsequent aspects of the study. Notably, however, longitudinal comparisons were limited by shorter follow-up in the control group. Additionally, while early benefits were consistent, long-term differences in outcome between groups were not definitively established.

Image: PD

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