Antero- vs. retrograde nerve dissection in parotidectomy: a systematic review and meta-analysis

The retrograde approach (RP) to nerve identification is a method seldom used in parotid surgery. A systematic review comparing this method to the standard anterograde approach (AP) with respect to facial nerve palsy (FNP) does not currently exist.

In a meta-analysis according to the PRISMA statement, eight publications, including one randomized controlled trial, were selected. The primary aim was to compare the temporary and permanent FNP resulting from the two dissection methods. Facial nerve function was graded according to the House-Brackmann Scale. The secondary goal was a comparison of the cut-suture times (CST), the volume of healthy tissue (VHT) dissected, the rates of postoperative hematoma (PH), and postoperative infection (PI).

Temporary FNP was noted in 18.2% in the RP group as well as in 34.4% in the AP group. Permanent FNP occurred in 0.9% RPs and 2.4% APs. According to the mixed-effect logistic regression model, there was no significant difference between the two groups in the pooled odds ratio (OR) for either temporary [OR 2.64, 95% confidence interval (CI) 0.97-7.21] or permanent FNP (OR 4.31, 95% CI 0.44-42.28). The CST was significantly shorter in the RP group (p = 0.005), with a significantly smaller VHT dissected (p < 0.0001). There were no differences regarding PH and PI.

The RP is a safe procedure with no significant difference in FNP rates when compared to the AP and, considering the shorter CST and the lesser VHT resected in the RP, it is superior to the AP. Surgeons engaged in parotidectomy should be familiar with both methods of dissection.