Morbidity of multimodal treatments including endoscopic surgery for sinonasal malignancies: Results of an international collaborative study on 940 patients (MUSES).

Introduction: In the management of sinonasal malignancies treatment-induced morbidity and mortality is gaining relevance both for surgical approaches (endoscopic and open resection) and non-surgical therapies. The aim of this multicenter study is to assess complications associated with endoscopic surgery and non-surgical treatments (neoadjuvant and/or adjuvant) for malignant sinonasal tumors.

Methods: All patients with nasoethmoidal malignancies treated with curative intent with endoscopic or endoscopic-assisted surgery at three referral centers with uniform management policies were included. Neo- and/or adjuvant (chemo)radiotherapy was administered according to histology and pathological report. Demographics, treatment characteristics, and complications related both to the surgical and non-surgical approaches were retrieved. The data were analyzed with univariate and multivariate statistics to assess independent predictors of complications.

Results: Nine hundred and forty patients were included, 643 males (68%) and 297 females (32%). A total of 225 complications were identified in 187 patients (19.9%): cerebrospinal fluid (CSF) leak (3.5%), mucocele (2.3%), surgical site bleeding (2.0%), epiphora (2.0%), and radionecrosis (2.0%) were the most common. Treatment-related mortality was 0.4%. Variables independently associated with complications at multivariate analysis were principally dural resection (OR 1.92), cranioendoscopic or multiportal resection (OR 2.93), dural repair with multilayer technique with less than three layers (OR 2.17), and graft different from iliotibial tract (OR 3.29).

Conclusion: Our study shows that modern endoscopic treatments and radiotherapy for sinonasal malignancies are associated with limited morbidity and treatment-related mortality. CSF leak and radionecrosis, although rare, remain the most frequent complications and should be further addressed by future research efforts.