Wound dehiscence after lumbar decompression: none with biportal endoscopy, 8.7% with the microscope

Design

Post hoc pooled analysis of two randomised trials

Population

211 patients having single-level lumbar decompression or discectomy

Primary outcome

Wound dehiscence needing resuturing

Effect

0.0% (biportal endoscopic) vs 8.7% (microscopic); OR 0.046 (95% CI 0.003 to 0.798)

This post hoc analysis pooled two randomised trials comparing biportal endoscopic spine surgery with microscopic surgery for single-level lumbar stenosis or disc herniation. The pooled sample was 211 patients (108 endoscopic, 103 microscopic). The outcome was wound dehiscence needing resuturing after suture removal.

Nine patients (4.3%) had dehiscence, all in the microscopic group: 0.0% against 8.7% (OR 0.046, 95% CI 0.003 to 0.798). Across the whole cohort, an incision of 35 mm or more had the highest risk ratio (15.44), followed by drain output of 100 mL or more (8.55) and a white cell count change of 2 × 10³/µL or more (7.78). Within the microscopic group, drainage of 100 mL or more was the only significant factor (RR 9.17).

The trials were not designed for this outcome, there were only nine events, and the confidence interval is extremely wide. The authors call the findings hypothesis-generating. Smaller incisions are a plausible reason, but the result is not a reason to change the choice of technique.

• Keep incisions as short as the exposure safely allows; length of 35 mm or more carried the highest risk here.
• Watch the wound closely when drain output reaches 100 mL or more after microscopic decompression.
• Check the wound at suture removal and plan early review for those with high drainage.
• Do not pick a technique on this analysis alone; it was post hoc, with nine events.
• Record dehiscence and resuturing in your own audit.

Why it matters

Wound dehiscence is a minor complication that is rarely compared between techniques, yet it leads to reoperation and delays recovery.

Don't overread it

A post hoc pooled analysis with nine events cannot show that biportal endoscopy prevents wound dehiscence.

The statistics, in plain English

With zero events in one arm and nine overall, the odds ratio is unstable: the interval of 0.003 to 0.798 allows anything from near-total protection to a modest reduction. Relative risks from small event counts, such as 15.44, are especially imprecise.

Read the rest in the app

You have read your two free briefings this month. The app carries all 27 specialties, every morning, free — and this finding is waiting in it.

Get Daily Doctor — free

Scan to keep reading on your phone. No account needed to start.