Complications
In total, 144 patients (42.1%) had a post-operative complication, including 114 surgical complications (33.3%) and 30 medical complications (8.8%). There were eight flap failures (2.3%) and three patients died whilst in hospital (0.9%). A summary of all complications is provided in table 2. There was a 10% increase in the odds of developing a complication per additional hour of operative time (OR 1.10, 95%CI 1.02 – 1.17, p=0.008). When dichotomized, operations > 9 hours duration were associated with an 82% increase in the odds of developing a complication compared to operations ≤ 9 hours duration (OR 1.82, 95%CI 1.17-2.83, p=0.008). After adjusting for the effect of patient age, ASA status, prior radiotherapy, defect type, reconstruction and elective tracheostomy, there was a 11% increase in odds of developing a complication per additional hour of operative time (OR 1.11, 95%CI 1.03 – 1.21, p=0.011) and a 92% increase for patients undergoing operations > 9 hours duration compared to ≤ 9 hours duration (OR 1.92, 95%CI 1.18 – 3.13, p=0.009) (Table 3). Increasing patient age (continuous p=0.002; dichotomized ≥ 75 years p=0.03) and elective tracheostomy (p=0.015) were other significant predictors of complications (Figure 1).
There was a 12% increase in the odds of developing a surgical complication per additional hour of operative time (OR 1.12, 95%CI 1.04 – 1.20, p=0.002). Operations > 9 hours duration were associated with an 89% increase in the odds of developing a surgical complication compared to operations ≤ 9 hours duration (OR 1.89, 95%CI 1.20-2.98, p=0.006). After adjusting for the effect of patient age, ASA status, prior radiotherapy, defect type, and reconstruction, there was a 13% increase in odds of developing a surgical complication per additional hour of operative time (OR 1.13, 95%CI 1.04 – 1.23, p=0.004) and a 101% increase in patients undergoing operations > 9 hours duration compared to operations ≤ 9 hours duration (OR 2.01, 95%CI 1.23 – 3.28, p=0.005) (Table 4). Operative time was not associated with medical complications when analyzed per hour (OR 1.02, 95%CI 0.91 – 1.14, p=0.76) or when dichotomized (OR 1.38, 95%CI 0.65 – 2.97, p=0.40).