The Role of Preoperative Abdominal Ultrasound in the Preparation of Patients Undergoing Primary Metabolic and Bariatric Surgery: A Machine Learning Algorithm on 4418 Patients' Records.

BACKGROUND: The utility of preoperative abdominal ultrasonography (US) in evaluating patients with obesity before metabolic bariatric surgery (MBS) remains ambiguously defined. METHOD: Retrospective analysis whereby patients were classified into four groups based on ultrasound results. Group 1 had normal findings. Group 2 had non-significant findings that did not affect the planned procedure. Group 3 required additional or follow-up surgeries without changing the surgical plan. Group 4, impacting the procedure, needed further investigations and was subdivided into 4A, delaying surgery for more assessments, and 4B, altering or canceling the procedure due to critical findings. Machine learning techniques were utilized to identify variables. RESULTS: Four thousand four hundred eighteen patients' records were analyzed. Group 1 was 45.7%. Group 2, 35.7%; Group 3, 17.0%; Group 4, 1.5%, Group 4A, 0.8%; and Group 4B, 0.7%, where surgeries were either canceled (0.3%) or postponed (0.4%). The hyperparameter tuning process identified a Decision Tree classifier with a maximum tree depth of 7 as the most effective model. The model demonstrated high effectiveness in identifying patients who would benefit from preoperative ultrasound before MBS, with training and testing accuracies of 0.983 and 0.985. It also showed high precision (0.954), recall (0.962), F1 score (0.958), and an AUC of 0.976. CONCLUSION: Our study found that preoperative ultrasound demonstrated clinical utility for a subset of patients undergoing metabolic bariatric surgery. Specifically, 15.9% of the cohort benefited from the identification of chronic calculous cholecystitis, leading to concomitant cholecystectomy. Additionally, surgery was postponed in 1.4% of the cases due to other findings. While these findings indicate a potential benefit in certain cases, further research, including a cost-benefit analysis, is necessary to fully evaluate routine preoperative ultrasound's overall utility and economic impact in this patient population.

Laparoscopic sleeve gastrectomy vs one-anastomosis gastric bypass 5-year follow-up: a single-blinded randomized controlled trial.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is the most performed bariatric procedure worldwide, whereas one-anastomosis gastric bypass (OAGB) is the third most performed procedure. Both procedures have reported good weight loss (WL) and low complications. However, should both have differences in the durability of WL and malnutrition? METHODS: A single-blinded, randomized controlled trial of 300 patients was conducted to compare the outcomes of LSG and OAGB over a 5-year follow-up. The primary endpoint was WL in percentages of total WL (%TWL) and excess WL (%EWL). The secondary endpoints were complications, gastroesophageal reflux disease (GERD), associated medical problems, bariatric analysis and reporting outcome system (BAROS) assessment, and weight recurrence (WR). RESULTS: Overall, 201 patients (96 in the LSG group and 105 in the OAGB group) completed 5 years of follow-up. OAGB had significantly higher %TWL and %EWL than those of LSG throughout the follow-up. LSG had significantly higher WR and GERD. Both procedures had significant improvement in associated medical problems and BAROS scores compared with baseline, with no significant difference. WR was associated with higher relapse of associated medical conditions after initial remission and with lower BAROS scores regarding WL scores. CONCLUSION: OAGB had significantly higher WL, less WR, and less GERD. However, it had a higher incidence of bile reflux. Both procedures had comparable complication rates, excellent remissions in associated medical problems, and improved quality of life. WR was associated with significantly more relapse of associated medical problems and significantly lower BAROS scores.

Two-Year Results of the Banded Versus Non-banded Re-sleeve Gastrectomy as a Secondary Weight Loss Procedure After the Failure of Primary Sleeve Gastrectomy: a Randomized Controlled Trial.

BACKGROUND: Insufficient weight loss or weight regain has been reported in up to 30% of patients after laparoscopic sleeve gastrectomy (LSG). Approximately 4.5% of patients who undergo LSG need revisional surgery for a dilated sleeve. METHODS: This randomized controlled trial compared the outcomes between banded (BLSG) and non-banded re-LSG (NBLSG) after weight regain. Percentage excess body weight loss (%EWL), percentage total weight loss (%TWL), associated medical problems, gastric volume measurement, and endoscopy were measured preoperatively and 1 and 2 years postoperatively. RESULTS: Both groups (25 patients each) achieved similar % EWL and %TWL at six months, one year, and two years postoperatively (%EWL 46.9 vs. 43.6, 83.7 vs. 86.3, and 85.7 vs. 83.9) (p= > 0.151) (%TWL 23.9 vs. 21.8, 43.1 vs .43.3, 44.2 vs. 42.2) (p=>0.342), respectively. However, the body mass index was significantly lower with BLSG (24.9 vs. NBLSG, 26.9). Both groups showed a significant reduction in stomach volume after two years (BLSG -248.4 mL vs. NBLSG -215.8 mL). Food tolerance (FT) scores were significantly reduced in both groups, whereby BSLG had significantly lower FT with an average of -1.1 point. No significant differences were observed regarding improvement of the associated medical problems after the first and two years after revisional LSG or the postoperative complications between both groups. CONCLUSION: Laparoscopic re-LSG is feasible and safe with satisfactory outcomes in patients with weight regain after LSG who have gastric dilatation without reflux esophagitis. Both groups had comparable significant weight loss effects and improvement of associated medical problems. The BLSG tends to have a more stable weight loss after two years with a significantly lower BMI, lower stomach volume, and less weight regain. Food tolerance decreased in both groups but reduced more in the BLSG group. After a 2-year follow-up, we may regard both procedures are safe, with no significant differences in the occurrence of complications and nutritional deficits.

How Good is Stratification and Prediction Model Analysis Between Primary and Revisional Roux-en-Y Gastric Bypass Surgery? A Multi-center Study and Narrative Review.

INTRODUCTIONS: Revision surgery because of weight recurrence is performed in 2.5-33% of primary vertical banded gastroplasty (VBG), laparoscopic sleeve gastrectomy (LSG), and gastric band (GB) cases. These cases qualify for revisional Roux-en-Y gastric bypass (RRYGB). METHODS: This retrospective cohort study analyzed data from 2008 to 2019. A stratification analysis and multivariate logistic regression for prediction modeling compared the possibility of sufficient % excess weight loss (%EWL) ≥ 50 or insufficient %EWL < 50 between three different RRYGB procedures, with primary Roux-en-Y gastric bypass (PRYGB) as the control during 2 years of follow-up. A narrative review was conducted to test the presence of prediction models in the literature and their internal and external validity. RESULTS: A total of 558 patients underwent PRYGB, and 338 underwent RRYGB after VBG, LSG, and GB, and completed 2 years of follow-up. Overall, 32.2% of patients after RRYGB had a sufficient %EWL ≥ 50 after 2 years, compared to 71.3% after PRYGB (p ≤ 0.001). The total %EWL after the revision surgeries for VBG, LSG, and GB was 68.5%, 74.2%, and 64.1%, respectively (p ≤ 0.001). After correcting for confounding factors, the baseline odds ratio (OR) or sufficient %EWL ≥ 50 after PRYGB, LSG, VBG, and GB was 2.4, 1.45, 0.29, and 0.32, respectively (p ≤ 0.001). Age was the only significant variable in the prediction model (p = 0.0016). It was impossible to develop a validated model after revision surgery because of the differences between stratification and the prediction model. The narrative review showed only 10.2% presence of validation in the prediction models, and 52.5% had external validation. CONCLUSION: Overall, 32.2% of all patients after revisional surgery had a sufficient %EWL ≥ 50 after 2 years, compared to PRYGB. LSG had the best outcome in the revisional surgery group in the sufficient %EWL group and the best outcome in the insufficient %EWL group. The skewness between the prediction model and stratification resulted in a partially non-functional prediction model.