Maximum phonation time: an independent predictor of late-onset pneumonia after esophageal cancer surgery.

Dysphagia after esophagectomy is a major risk factor for aspiration pneumonia, thus preoperative assessment of swallowing function is important. The maximum phonation time (MPT) is a simple indicator of phonatory function and also correlates with muscle strength associated with swallowing. This study aimed to determine whether preoperative MPT can predict postoperative aspiration pneumonia. The study included 409 consecutive patients who underwent esophagectomy for esophageal cancer between 2017 and 2021. Pneumonia detected by routine computed tomography on postoperative days 5-6 was defined as early-onset pneumonia, and pneumonia that developed later (most often aspiration pneumonia) was defined as late-onset pneumonia. The correlation between late-onset pneumonia and preoperative MPT was investigated. Patients were classified into short MPT (<15 seconds for males and <10 seconds for females, n = 156) and normal MPT groups (≥15 seconds for males and ≥10 seconds for females, n = 253). The short MPT group was significantly older, had a lower serum albumin level and vital capacity, and had a significantly higher incidence of late-onset pneumonia (18.6 vs. 6.7%, P < 0.001). Multivariate analysis showed that short MPT was an independent risk factor for late-onset pneumonia (odds ratio: 2.26, P = 0.026). The incidence of late-onset pneumonia was significantly higher in the short MPT group (15.6 vs. 4.7%, P = 0.004), even after propensity score matching adjusted for clinical characteristics. MPT is a useful predictor for late-onset pneumonia after esophagectomy.