Poster Presentation ANZOS-ASLM-ICCR 2019

Does preoperative weight loss predict early weight loss post-bariatric surgery? (#188)

Ramy H Bishay 1 2 , Sarah Driscoll 1 , Gideon Meyerowitz-Katz 3 , Michael Edye 1 4 , Michael Devadas 1 4 , Brendan Ryan 1 4 , Mark Mclean 1 2 , Glen F Maberly 2 3 , Tien-Ming Hng 1 2 , Annette McDonald 1 , Caroline Cusack 1 , Golo Ahlenstiel 1 2 5
  1. Metabolic & Weight Loss Program, Department of Endocrinology and Diabetes, Blacktown Hospital, Blacktown, NSW, Australia
  2. School of Medicine, University of Western Sydney, Sydney, NSW, Australia
  3. Western Sydney Diabetes, Integrated and Community Health Directorate, Blacktown Hospital Department of Endocrinology and Diabetes, Western Sydney Local Health District, Sydney, NSW, Australia
  4. Department of Surgery, Blacktown Hospital, Blacktown, NSW, Australia
  5. Storr Liver Centre, Westmead Millennium Institute, Westmead Hospital, University of Sydney, Sydney, NSW, Australia

BACKGROUND Preconditioning of patients preparing for bariatric (metabolic) surgery is largely influenced by local clinical expertise and is encumbered by the lack of structured, evidence-based clinical guidelines that predict the most optimal clinical outcomes. There are conflicting views concerning the amount of pre-operative weight loss that is required to increase post-surgical weight loss.

METHODS We analysed prospectively collected data on surgically treated patients enrolled in the Blacktown Hospital Metabolic and Weight Loss Program, a publicly-funded multidisciplinary tertiary hospital program with integration of bariatric surgery, during 2017 - June 2019. Eligible patients had a BMI > 35 kg/m2 with co-existent type 2 diabetes or BMI > 40 kg/m2 with 2 obesity-related complications.

RESULTS Of 27 patients who received metabolic surgery, 56% were female, average BMI at enrolment was 49.9 kg/m2 and average age 50.1 yrs. Sleeve gastrectomy was the dominant procedure (78% vs. single anastomosis gastric bypass, 22%). Patients who achieved a total body weight loss (TBWL) of <5% (n=6), 5.1-10% (n=13), 10.1-15% (n=3), and > 15.1% (n=5) had excess weight loss (EWL) of 23, 31, 29 and 32% at 3-months and 32, 46, 42, and 45% at 6-months. Analysis of weight loss as a binary variable using a logistic model correcting for age, gender and enrolment BMI, increasing weight loss preoperatively was associated with increasing likelihood of achieving > 25% EWL at 3-months (odds ratio 4.1 [1.1-15.1, p=0.029]). There were no apparent differences among surgical methods at 3 and 6 months.

CONCLUSIONS In this small cohort, modest weight loss preoperatively appears to increase the likelihood of early post-operative weight loss. Evaluation of longer-term and larger cohort data as well as incident rates of surgical complications, amelioration of obesity-related disease and health economics analysis is ongoing.