[Application of free tissue flaps using the facial artery and vein/retromandibular vein as recipient vessels in the repair of postoperative nasopharyngeal skull base necrosis].

Objective: To evaluate the clinical efficacy of free tissue flap transplantation for repairing skull base defects following osteoradionecrosis after radiotherapy for nasopharyngeal carcinoma (NPC), with the facial artery and either the facial vein or retromandibular vein used as recipient vessels via a trans-submandibular, anterior masseteric, and transpterygomaxillary fissure approach. Methods: A retrospective analysis was conducted on the clinical data of 25 patients (18 males and 7 females, aged from 45 to 73 years) with postradiation nasopharyngeal necrosis (PRNN), admitted to the Department of Otorhinolaryngology, Head and Neck Surgery, the Third Affiliated Hospital of Sun Yat-sen University, between May 2024 and October 2025. All patients underwent free tissue flap reconstruction via the trans-maxillary approach to repair skull base defects. The recipient artery was the facial artery in all cases. The recipient veins were the facial vein in 16 cases and the retromandibular vein in 9 cases. Flap types included the anterolateral thigh fascial flap (ALT flap, 19 cases), forearm flap (4 cases), and anterolateral thigh flap (2 cases). Nasal endoscopy and/or contrast-enhanced nasopharyngeal MRI were performed at 1 week, 1 month, and 3 months postoperatively to access flap survival, wound healing status, and reconstructive outcomes. Statistical analysis was performed using SPSS 27.0. Results: During a follow-up period of 4 to 21 months, complete flap survival was observed in 24 patients, corresponding to an overall flap survival rate of 96% (24/25). One case of anterolateral thigh fascial adipofascial flap developed postoperative necrosis due to arterial anastomotic thrombosis, and the wound healed after endoscopic debridement. The median operation time was 836 (597, 986) min [M (Q1, Q3)]; the median intraoperative blood loss was 300 (200, 400) ml; the median postoperative hospital stay was 25 (18, 30) d; and there were no complications at the donor site. All flaps in the facial vein group survived (16/16), whereas 8 of 9 flaps in the retromandibular vein group survived, and there was no statistically significant difference between the two groups (Fisher's exact test, P=0.36). The postoperative mortality rate was 1/16 in the facial vein group and 2/9 in the retromandibular vein group, with no statistically significant difference between the two groups (χ²=0.290, P=0.295). Postoperative nasogastric intubation was performed in 24 patients, with a median indwelling time of 21 (12, 32) d; one patient underwent concomitant gastrostomy. Postoperative pathology confirmed 20 cases of simple nasopharyngeal necrotizing inflammation, 4 cases of necrotizing inflammation combined with squamous cell carcinoma (recurrence of nasopharyngeal carcinoma), and 1 case of necrotizing inflammation combined with post-radiation sarcoma. Three patients died after the operation: one died of intracranial infection, one of massive hemorrhage, and one of respiratory failure due to severe pneumonia. Conclusion: The use of the facial artery and either the vein or retromandibular vein system as recipient vessels for free tissue flap transplantation via the trans-maxillary approach appears to be feasible and effective option for repairing nasopharyngeal skull base defects after radiotherapy for NPC with a high flap survival rate.