Single service otolaryngology head and neck surgery free flap reconstruction of head and neck ablative defects-a retrospective single centre review of our initial 6-year experience

Background: Conventionally, head and neck free flap reconstruction performed as a shared responsibility of otolaryngology and plastic surgeons. The purpose of this study is to evaluate outcomes and identify factors that contribute to complications of free flap reconstructions performed during the establishment of singleservice head and neck surgical free flap reconstruction model at the Royal Adelaide Hospital (RAH). Methods: Retrospective cohort study of patients undergoing free flap reconstruction between September 2015 and August 2021 by the Otolaryngology, Head and Neck Surgery (OHNS) Unit. Patients were included if they had microvascular free tissue transfer, performed by the OHNS department at the RAH. Patients who underwent reconstruction with regional flaps or had surgery performed by plastic surgery department were excluded. The primary outcome of interest was free flap survival. Secondary outcome included surgical, medical complications and hospital/intensive care unit (ICU) length of stay. Univariate binary logistic regression models were used to investigate the association between primary, secondary outcomes and various predictors. Results: Two hundred patients were identified with a microsurgical free flap success rate of 98.5%. The timing of free flap failure was at two, five and eight days post-operatively. Operation time was shown to be associated with flap failure (P=0.0213). Nineteen (9.5%) cases required return to theatre. Eight (4.0%) for anastomosis revision, six (3.0%) for post-operative bleed/hematoma, three (1.5%) for debridement of recipient site infection and two (1.0%) for further resection and neck dissection, unrelated to post-operative complications. The rate of surgical and medical complications was 25.5% and 40.5% respectively. There was a statistically significant association between American Society of Anesthesiologists (ASA) status and rate of surgical (P=0.0026)/medical complications (P<0.001). Hypertension (P=0.0167) and operation time (P<0.0001) showed a statistically significant association with hospital length of stay. Conclusions: Our data confirms transitioning to a single-service head and neck surgical free flap reconstruction model solely within the OHNS Unit is obtainable whilst maintaining internationally recognized standards and providing patients multiple benefits in the process.