There remains no consensus on the definition or value of early oral feeding after head and neck surgery. The main objective of this study was to determine how immediate oral feeding (IOF) with soft diet within 2 days following free-flap reconstruction of the oral cavity affected severe post-operative morbidity within 30 days and length of hospital stay (LoS).

A retrospective cohort study was carried out in 2021–2023 in our tertiary hospital center. The associations between severe post-operative morbidity and LoS with the independent variable of IOF were analyzed by multivariate regression analysis. We also examined the factors associated with delayed oral feeding (DOF); lack of oral feeding within 10 post-operative days. The confounding variables adjusted for were demographic-related (age, sex), comorbidity-related (ASA score, undernutrition, prior history), and surgery-related (substance loss type/location, flap type).

Inclusion was 132 patients: n = 29/132 (22 %) IOF patients versus n = 103/132 (78 %) patients undergoing oral feeding after ≥3 post-operative days. IOF was found independently associated with reduced severe post-operative morbidity within 30 days (AOR 0.3[0.1–0.8], p = 0.01) and shorter length of stay (AEE -6.7 [-11.8–-1.6], p = 0.01) compared to oral feeding after ≥3 post-operative days. DOF was found positively associated with cardiovascular history (AOR 2.7[1.1–7.3], p = 0.04) but negatively associated with a history of head and neck surgery with radiotherapy (AOR 0.4[0.1–0.8], p = 0.05).

Protocols for post-operative oral feeding should consider IOF. Criteria for good candidates for IOF require further definition for surgeons to implement IOF more widely.