Implication of Preoperative Weight Loss on 30-day Complication Rate after Bariatric Surgery And Association of Pre-Operative Anemia with need of Intra/Post-Op Blood transfusion of Laparoscopic Sleeve Gastrectomy

Abstract

Abstract1 Background: The aim of this study is to evaluate the impact of preoperative weight loss on surgical outcomes and operating room (OR) times after primary bariatric procedures, including laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (RYGB). Study Design: A retrospective cohort study uses the 2021 MBSAQIP dataset. Preoperative total weight loss (TWL)% was calculated. Patients were then divided in to 4 groups: those with no weight loss, lost to %, lost ≥5% to %, or lost ≥10% TWL preoperatively. These groups were then stratified into those with BMI less than 50 kg/m2 and those with BMI 50 kg/m2 or more and 30-day outcomes and OR times were compared. Results: Analysis included 171,010 patients. For BMI less than 50 kg/m2, preoperative weight loss led to no consistent improvement in surgical outcomes. Although >0% to % TWL led to a decrease in intra- and postoperative occurrences after RYGB and a decrease in reoperation rates after LSG, these observations were not seen in those with higher degree of weight loss. In patients with BMI 50 kg/m2 or more, preoperative weight loss showed a consistent improvement in reintervention rates after LSG, and readmission rates after RYGB. There was no improvement in other outcomes, however, irrespective of degree of preoperative weight loss. Conclusions: In patients undergoing primary bariatric surgery, preoperative weight loss does not lead to a consistent improvement in outcomes or OR times. In those with BMI 50 kg/m2 or more, there may be improvement in select outcomes that is procedure-specific. Overall, these data do not support a uniform policy of preoperative weight loss, although selective use in some high-risk patients may be appropriate.

Abstract 2 Background: Obesity is a growing global epidemic and is linked to many chronic conditions. Laparoscopic Sleeve Gastrectomy (LSG) is the most common surgical treatment for severe obesity. Anemia is common in patients with obesity, and association between preoperative anemia and post-operative outcomes after LSG has not been studied. Aim of this study is to evaluate the association of anemia with 30-day post-operative outcomes including need for peri-operative blood transfusion. Methods: This retrospective cohort study utilized the 2022 Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) dataset to investigate the association of pre-operative anemia, defined as hematocrit (Hct) below 41 for men and below 36 for women, among adult patients undergoing primary LSG with need of intra/post-op blood transfusion as the primary outcome. For our secondary outcomes we studied preoperative anemia’s association with 30-day complications, reoperation, and readmission as well as length of hospital stay. Logistic regression models and negative binomal regression models were used to explore binary outcomes. Results: Our analysis includes 130,475 LSG patients, of which 10.2% (13,281 patients) had pre-operative anemia. In the fully adjusted models, pre-operative anemia was associated with higher odds for transfusion (OR1.80: 95%CI: 1.44, 2.26), 30-day complications (1.17; 95% CI: 1.04, 1.33), 30-day readmission (1.21: 95% CI: 1.09, 1.37), and longer length of hospital stay (IRR 1.07: 1.05, 1.09). However, there was no association between preoperative anemia and odds of 30-day reoperation. Conclusion: In patients undergoing primary LSG, pre-operative anemia was associated with a higher risk of blood transfusion, and 30-day complications, readmission, as well as longer length of hospital stay. Whether addressing pre-operative anemia could reduce post-operative outcomes after LSG is unclear but should be explored by future research.