Risk stratification of 7,732 hepatectomy cases in 2011 from the National Clinical Database for Japan.
BACKGROUND
There has been no report on risk stratification for hepatectomy using a nationwide surgical database in Japan. The objective of this study was to evaluate mortality and variables associated with surgical outcomes of hepatectomy at a national level.


METHODS
We analyzed records of 7,732 patients who underwent hepatectomy for more than 1 segment (MOS) during 2011 in 987 different hospitals, as identified in the National Clinical Database (NCD) of Japan. The NCD captured 30-day morbidity and mortality as well as 90-day in-hospital mortality outcomes, which were submitted through a web-based data entry system. Based on 80% of the population, independent predictors for 30-day mortality and 90-day in-hospital mortality were calculated using a logistic regression model. The risk factors were validated with the remaining 20% of the cohort.


RESULTS
The median postoperative length of hospitalization was 16.0 days. The overall patient morbidity rate was 32.1%. Thirty-day mortality and 90-day in-hospital mortality rates were 2.0% and 4.0%, respectively. Totals of 14 and 23 risk factors were respectively identified for 30-day mortality and 90-day in-hospital mortality. Factors associated with risk for 90-day in-hospital mortality were preoperative condition and comorbidity, operative indication (emergency surgery, intrahepatic/perihilar cholangiocarcinoma, or gallbladder cancer), preoperative laboratory data, and extent and location of resected segments (segment 1, 7, or 8). As a performance metric, c-indices of 30-day mortality and 90-day in-hospital mortality were 0.714 and 0.761, respectively.


CONCLUSIONS
Here we report the first risk stratification analysis of hepatectomy using a Japanese nationwide surgical database. This system would predict surgical outcomes of hepatectomy and be useful to evaluate and benchmark performance.
Japanese Society of Gastroenterological Surgery (JSGS) database committee; Department of Regenerative Surgery, Fukushima Medical University, Fukushima City, Japan.
Akira
A
Kenjo
Japanese Society of Gastroenterological Surgery (JSGS) database committee; National Clinical Database, Tokyo, Japan; Department of Healthcare Quality Assessment, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
Hiroaki
H
Miyata
Japanese Society of Gastroenterological Surgery (JSGS) database committee; Department of Regenerative Surgery, Fukushima Medical University, Fukushima City, Japan. Electronic address: mgotoh@fmu.ac.jp.
Mitsukazu
M
Gotoh
Japanese Society of Gastroenterological Surgery (JSGS) database committee; Department of Surgery, Graduate School of Medicine, Keio University, Tokyo, Japan.
Yukou
Y
Kitagawa
Japanese Society of Gastroenterological Surgery (JSGS) database committee; Department of Digestive and Pediatric Surgery, The University of Tokushima Graduate School, Tokushima, Japan.
Mitsuo
M
Shimada
Japanese Society of Gastroenterological Surgery (JSGS) database committee; Department of Gastroenterological Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.
Hideo
H
Baba
Japanese Society of Gastroenterological Surgery (JSGS) database committee; Department of Lower Gastrointestinal Surgery, Hyogo College of Medicine, Hyogo, Japan.
Naohiro
N
Tomita
Japanese Society of Gastroenterological Surgery (JSGS) database committee; First Department of Surgery, Yamagata University Faculty of Medicine, Yamagata, Japan.
Wataru
W
Kimura
JSGS; Department Surgical Oncology, Tokyo Medical and Dental University, Tokyo, Japan.
Kenichi
K
Sugihara
JSGS; Department of Gastroenterological Surgery, Osaka University, Graduate School of Medicine, Osaka, Japan.
Masaki
M
Mori
D000368:Aged; D016208:Databases, Factual; D005260:Female; D006498:Hepatectomy / Q000401:mortality / Q000706:statistics & numerical data*; D017052:Hospital Mortality; D006801:Humans; D007564:Japan / Q000453:epidemiology; D007902:Length of Stay / Q000706:statistics & numerical data; D008107:Liver Diseases / Q000401:mortality / Q000601:surgery*; D008297:Male; D011237:Predictive Value of Tests; D018570:Risk Assessment; D012307:Risk Factors