Accuracy of ultrasound diagnosis of nonalcoholic fatty liver disease in patients with classes II and III obesity: A pathological image study.

Liver biopsy is the gold standard method to diagnose nonalcoholic fatty liver disease (NAFLD). However, ultrasound is widely recommended as the first-line imaging test for individuals with suspected NAFLD. This study aimed to estimate the accuracy of ultrasound as a screening test for NAFLD compared to liver biopsy in a cohort of patients with class II and III obesity undergoing bariatric surgery. This retrospective study included patients undergoing Roux-en-Y gastric bypass in southern Brazil between 2010 and 2019 who were screened for NAFLD with both ultrasound and liver biopsy. All samples were collected by a core biopsy needle and were analyzed by the same pathologist. Sensitivity, specificity, and positive and negative predictive values of ultrasound were estimated. The final database included 227 patients, mostly female (84%) and white (83.6%), with a mean age of 42.5 ± 10.2 years and a mean preoperative body mass index of 49.5 ± 8.4 kg/m2. A total of 153 subjects (67.4%) were diagnosed with NAFLD through liver biopsies: 41 (18%) had fatty liver and 112 (49.3%) had nonalcoholic steatohepatitis. Ultrasound sensitivity was 88.9% and specificity was 44.6%. Positive and negative predictive values were 76.8% and 66.0%, respectively. Positive likelihood ratio was 1.6 (95% CI 1.30-1.98), and negative likelihood ratio was 0.25 (95% CI 0.15-0.42). Therefore, approximately three every four subjects with an ultrasound suggesting NAFLD were true positives. Ultrasound showed a good sensitivity in detecting NAFLD in patients with class II and III obesity.

Development and Validation of a Predictive Model of Success in Bariatric Surgery.

PURPOSE: There are no criteria to establish priority for bariatric surgery candidates in the public health system in several countries. The aim of this study is to identify preoperative characteristics that allow predicting the success after bariatric surgery. MATERIALS AND METHODS: Four hundred and sixty-one patients submitted to Roux-en-Y gastric bypass were included. Success of the surgery was defined as the sum of five outcome variables, assessed at baseline and 12 months after the surgery: excess weight loss, use of continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) as a treatment for obstructive sleep apnea (OSA), daily number of antidiabetics, daily number of antihypertensive drugs, and all-cause mortality. Partial least squares (PLS) regression and multiple linear regression were performed to identify preoperative predictors. We performed a 90/10 split of the dataset in train and test sets and ran a leave-one-out cross-validation on the train set and the best PLS model was chosen based on goodness-of-fit criteria. RESULTS: The preoperative predictors of success after bariatric surgery included lower age, presence of non-alcoholic fatty liver disease and OSA, more years of CPAP/BiPAP use, negative history of cardiovascular disease, and lower number of antihypertensive drugs. The PLS model displayed a mean absolute percent error of 0.1121 in the test portion of the dataset, leading to accurate predictions of postoperative outcomes. CONCLUSION: This success index allows prioritizing patients with the best indication for the procedure and could be incorporated in the public health system as a support tool in the decision-making process.

Neonatal Outcomes of Pregnancy Following Roux-en-Y Gastric Bypass: a Matched Case-Control Study.

PURPOSE: To compare perinatal outcomes and to assess the predictors of birth weight (BW) after Roux-en-Y gastric bypass (RYGB) to those women unexposed to bariatric surgery. MATERIALS AND METHODS: Singleton births from women submitted to RYGB (BSG) were matched to two control births by maternal age, delivery year, and gender. Control group 1 (CG1) and control group 2 (CG2) were selected according to the prepregnancy body mass index (BMI) < 35 kg/m2 and ≥ 35 kg/m2, respectively, without previous bariatric surgery. RESULTS: Fifty-eight pregnancies were evaluated in each group (n = 174). Neonates born after RYGB presented lower BW compared to CG1 (mean difference - 182.3 g; 95% CI - 333; - 31, P = 0.018) and CG2 (mean difference - 306.6 g, 95% CI - 502; - 111, P = 0.02). Although gestational age (GA) was similar (P = 0.219), fetal growth rate (in grams) per gestational week was higher in CG2 (ß = 196.27, P < 0.001) vs. BSG (ß = 127.65, P < 0.001), irrespective of gestational weight gain (GWG). Pregnancies post-RYGB showed lower GWG, lower BW, and higher prevalence of cesarean section than CG1 and were associated with lower BW, smaller cephalic perimeter, lower prevalence of macrosomia, hypertension, and gestational diabetes than CG2. CONCLUSION: Birth weight was higher in neonates from women with higher prepregnancy BMI, as compared to births from women submitted to RYGB, irrespective of GWG. Although nearly half of the RYGB mothers were classified with obesity at conception, those pregnancies were associated with better obstetric and neonatal outcomes than among women with prepregnancy BMI ≥ 35 kg/m2 who had never undergone RYGB.