Low frequency of bacteremia after an endoscopic resection for large colorectal tumors in spite of extensive submucosal exposure

Background: During an EMR or endoscopic submucosal dissection (ESD) for colorectal tumors, an injection needle catheter is passed through the contaminated endoscopic channel and may directly inoculate bacteria into the blood stream during submucosal injection. In addition, extensively exposed submucosa, especially with an ESD, directly contacts colonic luminal bacteria after the procedure, which may increase the risk of bacteremia. However, the incidence of bacteremia after an EMR or ESD for colorectal tumors has not been reported. Objective: To evaluate the frequency of bacteremia associated with an EMR or ESD for colon lesions. Design: A prospective study. Patients: A total of 40 patients who underwent a conventional EMR (n = 30), an EMR after circumferential pre-cutting (n = 3), or ESD (n = 7) for colorectal tumors. Interventions and Main Outcome Measurements: Blood cultures were obtained immediately before, 5 minutes after, and 30 minutes after the procedure. Patients were closely monitored for 24 hours after the procedure to detect the development of infectious complications. Results: Blood cultures at baseline and 5 minutes after the procedure were all negative. However, a blood culture at 30 minutes after the procedure showed a positive result in 1 of 40 patients (2.5%). This patient underwent a conventional EMR, and the isolated microorganism was coagulase-negative Stapbylococcus, which might be regarded as a contaminant. None of the 40 patients showed any signs or symptoms associated with infection. Limitation: The small sample size. Conclusions: An EMR, or even an ESD, for colon lesions may be considered a low-risk procedure for infectious complications that does not warrant prophylactic administration of antibiotics.