Mortality after common rectal surgery in Japan: A study on low anterior resection from a newly established nationwide large-scale clinical database

BACKGROUND: The health-care system, homogenous ethnicity, and operative strategy for lower rectal cancer surgery in Japan are to some extent unique compared to those in Western countries. The National Clinical Database is a newly established nationwide, large-scale surgical database in Japan. OBJECTIVE: To illuminate Japanese national standards of clinical care and provide a basis for efforts to optimize patient care, we used this database to construct a risk model for a common procedure in colorectal surgery-low anterior resection for lower rectal cancer. DESIGN: Data from the National Clinical Database on patients who underwent low anterior resection during 2011 were analyzed. Multiple logistic regression analyses were performed to generate predictive models of 30-day mortality and operative mortality. Receiver-operator characteristic curves were generated, and the concordance index was used to assess the model's discriminatory ability. RESULTS: During the study period, data from 16,695 patients who had undergone low anterior resection were collected. The mean age was 66.2 years and 64.5% were male; 1.1% required an emergency procedure. Raw 30-day mortality was 0.4% and operative mortality was 0.9%. The postoperative incidence of anastomotic leakage was 10.2%. The risk model showed the following variables to be independent risk factors for both 30- day and operative mortality: BMI greater than 30 kg/ m2, previous peripheral vascular disease, preoperative transfusions, and disseminated cancer. The concordance indices were 0.77 for operative mortality and 0.75 for 30- day mortality. LIMITATIONS: The National Clinical Database is newly established and data entry depends on each hospital. CONCLUSIONS: This is the first report of risk stratification on low anterior resection, as representative of rectal surgery, with the use of the large-scale national surgical database that we have recently established in Japan. The resulting risk models for 30-day and operative mortality from rectal surgery may provide important insights into the delivery of health care for patients undergoing GI surgery worldwide.