Introduction: Increases in length of hospital stay (LOS) after surgery are associated with significant burdens and costs for patients in otolaryngology. Although the relationship between LOS and surgical complications has been studied extensively for various head and neck procedures, its relationship to free flap surgery has not been explored.
Objective: To identify the patient risk factors and postoperative complications leading to prolonged length of stay and outlier LOS after free flap surgery.
Study Design: Retrospective cohort study of the American College of Surgeons National Quality Improvement Program (NSQIP) database, 2005-2014.
Methods: Current Procedural Terminology (CPT) codes were used to query the NSQIP database for patients who underwent free flap surgery. Outlier length of stay was defined as >75th percentile. Univariate analysis and logistic regression were used to determine the perioperative variables that influence outlier LOS. Mann-Whitney U tests and logistic regression were used to determine the complications that most contribute to increasing LOS and outlier LOS status.
Results: A total of 1,875 cases met our inclusion criteria. The 75th percentile for length of stay was 13 days. Female patients were more likely to stay in the hospital beyond 13 days (Odds ratio [OR]= 1.86; P=0.02), while patients over the age of 65 had significantly increased odds of outlier lengths of stay ([OR]=1.69; P=0.04). Additional preoperative factors that predict outlier status in hospital stay include contaminated wound classifications ([OR}=3.87; P<0.01), anemia ([OR]=1.90; P=0.01), and bleeding disorders ([OR]=3.32; P=0.03). Increased operation time (605.04 vs 538.63 minutes; P<0.01) and anesthesia duration (701.24 vs 621.26 minutes; P<0.01) were also significantly correlated to outlier LOS. Of the complications significantly associated with prolonged length of stay on univariate analysis, the following variables independently predicted outlier LOS status: superficial surgical site infection ([OR]=4.68; P<0.01), graft failure ([OR]=4.25; P<0.01), pneumonia ([OR]=3.25; P=0.001), ventilator dependent respiratory failure ([OR]=5.57; P<0.01), and urinary tract infection ([OR]= 3.590; P=0.033).
Conclusion: Our study found that both surgical and medical factors are predictive of increased length of stay. Of the significant surgical complications, the strongest predictor of outlier LOS was superficial surgical site infection. Of the significant medical complications, the strongest predictor was ventilatory dependent respiratory failure. Our study highlights the postoperative complications in free flap surgery that are predictive of extended length of hospital stay. This provides support to the work of others that highlight the importance of adequate postoperative planning, risk stratification, and counseling. Further understanding of which factors leading to increased length of stay will allow for improved patient outcomes and reduction in hospital costs.