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

Abstract

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. 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. 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. 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/m, 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. The National Clinical Database is newly established and data entry depends on each hospital. 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.