Influence of Preoperative Oropharyngeal Microflora on the Occurrence of Postoperative Pneumonia and Survival in Patients Undergoing Esophagectomy for Esophageal Cancer.

Abstract

The aim of this study was to clarify the correlation between oropharyngeal microflora and postoperative complications as well as long-term survival after esophagectomy. Although the oral cavity is known to be a potential reservoir for pathogens, the influence of abnormal oropharyngeal microflora on the outcomes of patients undergoing esophagectomy remains unknown. This study included 675 patients who underwent esophagectomy between 2007 and 2014. Saliva samples from the oropharynx were collected 2 days before the operation. There were 442 patients with indigenous flora (Ind group) and 233 with allopatric flora. Among the patients with allopatric flora, 140 had antibiotic-sensitive microbes only (Allo-S group) while 93 had different types of antibiotic-resistant microbes (Allo-R group). We investigated the correlation between the types of oropharyngeal microflora and the incidence of postoperative complications as well as long-term outcomes. Sixteen microbes could be cultivated from the saliva samples. The incidence of postoperative pneumonia in the Allo-S and Allo-R groups was significantly higher than in the Ind group (P < 0.001). In addition, acute respiratory distress syndrome was more often observed in the Allo-R group than in the other groups (P = 0.002). A significantly higher rate of antibiotic use and longer hospital stays were observed in the Allo-R group compared with the Ind group. Multivariate logistic regression analysis revealed that the presence of allopatric antibiotic-resistant microbes in the oropharynx was an independent risk factor for postoperative pneumonia (odds ratio, 3.93; 95% confidence interval, 2.41-6.42). The overall survival was significantly poorer in the Allo-R group than in the other groups. Preoperative oropharyngeal culture is a simple and low-cost method that can predict both the occurrence of postoperative pneumonia and poor prognosis after esophagectomy.