title: A NSQIP Review of Major Morbidity and Mortality of Synchronous Liver Resection for Colorectal Metastasis Stratified by Extent of Liver Resection and Type of Colorectal Resection.
abstract: BACKGROUND
  Safety of synchronous hepatectomy and colorectal resection (CRR) for metastatic colorectal cancer remains controversial. We hypothesized that both the extent of hepatectomy and CRR influences postoperative outcomes.
  
  
  METHODS
  Prospective 2005-2013 ACS-NSQIP data were retrospectively reviewed for mortality and major morbidity (MM) after (1) isolated hepatectomy, (2) isolated CRR, and (3) synchronous resection for colorectal cancer. Hepatectomy and CRR risk categories were created based on mortality and MM of respective isolated resections. The synchronous cohort was then stratified based on risk categories. Cumulative asynchronous mortality and MM were estimated compared to that observed in the synchronous cohort via unadjusted relative risk and risk difference.
  
  
  RESULTS
  There were 43,408 patients identified. Among isolated hepatectomy patients (N = 6,661), trisectionectomy and right hepatectomy experienced the greatest mortality and were defined as "major" hepatectomy. Among isolated CRR patients (N = 35,825), diverted left colectomy, abdominoperineal resection, total abdominal colectomy, and total abdominal proctocolectomy experienced the greatest MM and were defined as "high risk" CRR. Synchronous patients (N = 922) were stratified by hepatectomy and CRR risk categories; mortality and MM varied from 0.9 to 5.0 % and 25.5 to 55.0 %, respectively. Mortality and MM were greatest for patients undergoing "high risk" CRR and "major" hepatectomy and lowest for synchronous CRR and "minor" hepatectomy. As both CRR and hepatectomy risk categories increased, there was a significant trend in increasing mortality and MM in synchronous patients. Additionally, comparison of the synchronous resections versus the estimated cumulative asynchronous outcomes showed that (1) mortality was significantly less after synchronous minor hepatectomy and either low or high risk CRR, and (2) neither mortality nor major morbidity differed significantly after major hepatectomy with either high or low risk CRR.
  
  
  CONCLUSIONS
  Major morbidity after synchronous hepatic and colorectal resections vary incrementally and are related to both the risk of hepatectomy and CRR. Stratification of outcomes by the hepatectomy and CRR components may reflect a more accurate description of risks. Comparison of synchronous and combined outcomes of individual operations supports a potential benefit for synchronous resections with minor hepatectomy.
authors.affiliation: Department of Surgery, Division of Subspecialty General Surgery, Section of Hepatobiliary and Pancreas Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, USA.|Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Surgical Outcomes Program, Mayo Clinic, Rochester, MN, USA.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Shubert
authors.affiliation: Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Surgical Outcomes Program, Mayo Clinic, Rochester, MN, USA.
authors.forename: Elizabeth B
authors.initials: EB
authors.lastname: Habermann
authors.affiliation: Department of Surgery, Division of Subspecialty General Surgery, Section of Hepatobiliary and Pancreas Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, USA.|Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Surgical Outcomes Program, Mayo Clinic, Rochester, MN, USA.
authors.forename: John R
authors.initials: JR
authors.lastname: Bergquist
authors.affiliation: Department of Surgery, Division of Subspecialty General Surgery, Section of Hepatobiliary and Pancreas Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, USA.|Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Surgical Outcomes Program, Mayo Clinic, Rochester, MN, USA.
authors.forename: Cornelius A
authors.initials: CA
authors.lastname: Thiels
authors.affiliation: Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Surgical Outcomes Program, Mayo Clinic, Rochester, MN, USA.
authors.forename: Kristine M
authors.initials: KM
authors.lastname: Thomsen
authors.affiliation: Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Surgical Outcomes Program, Mayo Clinic, Rochester, MN, USA.
authors.forename: Walter K
authors.initials: WK
authors.lastname: Kremers
authors.affiliation: Department of Surgery, Division of Subspecialty General Surgery, Section of Hepatobiliary and Pancreas Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Kendrick
authors.affiliation: Robert D. and Patricia E. Kern Center for the Science of Health Care Delivery, Surgical Outcomes Program, Mayo Clinic, Rochester, MN, USA.|Department of Surgery, Division of Colon and Rectal Surgery, Mayo Clinic, Rochester, MN, USA.
authors.forename: Robert R
authors.initials: RR
authors.lastname: Cima
authors.affiliation: Department of Surgery, Division of Subspecialty General Surgery, Section of Hepatobiliary and Pancreas Surgery, Mayo Clinic, 200 First Street SW, Rochester, MN, USA. nagorney.david@mayo.edu.
authors.forename: David M
authors.initials: DM
authors.lastname: Nagorney
mesh_terms: D000368:Aged; D003082:Colectomy; D015179:Colorectal Neoplasms / Q000473:pathology* / Q000601:surgery*; D005260:Female; D006498:Hepatectomy; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D012189:Retrospective Studies; D014481:United States
keywords: Colorectal metastasis; Extent of colorectal resection; Extent of liver resection; Risk stratification; Safety of synchronous resection; Synchronous liver resection