Anatomical Variation of Absent Facial Vein: Implications for Facial Reanimation Surgery.

Abstract

The facial vein is the standard recipient vessel in facial reanimation surgery. Its complete absence is rarely described but may cause major challenges during free functional muscle transfer (FFMT). This study aimed to determine the prevalence and predictors of facial vein absence and assess its surgical relevance in facial reanimation patients. A retrospective analysis of 198 patients who underwent FFMT between 2005 and 2025 was performed. Facial vein presence was evaluated intraoperatively, and all patients had preoperative Doppler ultrasonography. Potential predictors were analyzed using logistic regression and Fisher's exact test. Facial vein aplasia occurred in 12 patients. Aplasia was significantly associated with congenital etiology and syndromic palsy, especially Moebius syndrome. No associations with age, sex, operative time, or complications were found. Facial vein aplasia is strongly linked to congenital and syndromic palsy. Preoperative Doppler ultrasonography is recommended for identifying venous anomalies and optimizing surgical planning. Freiburger Register Klinischer Studien (FRKS): Number FRKS005811.