Association for Academic Surgery Obesity Is an Independent Risk Factor for Mortality in Otherwise Healthy Patients After Hepatectomy Maria Gabriela Urdaneta Perez, MD, Tabitha Garwe, PhD, MPH, Kenneth Stewart, PhD, Zoona Sarwar, MBBS, MS, and Katherine T. Morris, MD, FACS* Department of Surgery, Oklahoma University, Oklahoma City, Oklahoma article info Article history: Received 28 February 2020 Received in revised form 25 April 2020 Accepted 3 May 2020 Available online xxx Keywords: Hepatectomy Obese Healthy obese BMI Comorbidities Mortality abstract Background: Obesity is often associated with comorbidities that limit remnant liver recovery after hepatectomy. The extent to which obesity, in the absence of comorbidities, impacts surgical risk after hepatectomy is unknown. We hypothesized that an obese population without major comorbidities would not be at increased risk of adverse outcomes after hepatectomies. Methods: We performed a retrospective analysis identifying patients who underwent hep- atectomies from the American College of Surgeons National Surgical Quality Improvement Program data set 2005-2017. Outcomes of interest included the following: mortality, any morbidity, critical care complications, and failure to discharge home. Body mass index (BMI) was the primary variable of interest, grouped as 35 and <35 based on bivariate tests of associations with candidate cut-off points. In attempt to isolate the effect of obesity on outcomes among patients “without major comorbidities” (WOC), we included patients without diabetes, chronic obstructive pulmonary disease, renal insufficiency, and non- smokers; remaining patients were grouped as “with major comorbidities” (WC). Multivar- iable logistic regression was used to test whether obesity is independently associated with the outcomes of interest after adjustment for other covariates. Results: A total of 36,396 patients were included. There were 13,754 patients in the WOC group and 22,642 in the WC group. Among patients in the WOC group, the adjusted odds of mortality were 2.2 times higher for patients with a BMI 35 versus a BMI <35. Among the patients in the WC group, a BMI 35 was not a statistically significant predictor of mortality after adjustment for other covariates. Obese patients had increased odds of each outcome among the WOC group. Conclusions: Our hypothesis was refuted by these data. In fact, the adverse effect of obesity was more evident among healthy patients. ª 2020 Elsevier Inc. All rights reserved. Declarations of interest: none. * Corresponding author. O’Donoghue Research Building, 1122 NE 13th Street, Oklahoma City, OK, 73013. Tel.: þ1 (405) 2713010; fax: (405) 2713919. E-mail addresses: maria-urdanetaperez@ouhsc.edu (M.G. Urdaneta Perez), katherine-morris@ouhsc.edu (K.T. Morris). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.JournalofSurgicalResearch.com journal of surgical research  november 2020 (255) 50 e57 0022-4804/$ e see front matter ª 2020 Elsevier Inc. All rights reserved. https://doi.org/10.1016/j.jss.2020.05.024