Study Roundup

Published in December Issue             

Prevalence and Risk Factors for Bariatric Surgery Readmissions: Findings From 130,007 Admissions in the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program (MBSAQIP) (Annals of Surgery)

To evaluate national 30-day readmission rates for primary bariatric surgeries, 130,007 patients were identified from 698 MBSAQIP accredited centers from January 1, 2014 to December 31, 2014. Among these, 7,378 (5.7%) had laparoscopic adjustable gastric banding (LAGB), 80,646 (62.0%) had laparoscopic sleeve gastrectomy (LSG), and 41,983 (32.3%) had laparoscopic Roux-en-Y gastric bypass (LRYGB). A total of 5,663 (4.4%) patients were readmitted within 30 days for all causes. Patients undergoing LAGB had the lowest related readmission rate of 1.4%, followed by LSG (2.8%) and LRYGB (4.9%). Of patients who had a complication, 17.9% (n = 785) were readmitted, whereas those without readmission had a complication 1.9% of the time. The most common cause of a related readmission was nausea, vomiting, fluid, electrolyte and nutritional depletion (35.4%), followed by abdominal pain (13.5%), anastomotic leak (6.4%) and bleeding (5.8%) – accounting for more than 61% of readmissions. When compared with LAGB, LSG and LRYGB had significantly higher rates of readmission. Investigators concluded that national bariatric readmissions after primary procedures were closely associated with complications and varied based on the type of procedure.


Bariatric Surgery and the Risk of New-Onset Atrial Fibrillation in Swedish Obese Subjects (Journal of American College of Cardiology)

To investigate whether weight loss through bariatric surgery reduces the risk of new-onset atrial fibrillation a cohort of 4,021 participants from the Swedish Obese Subjects (SOS) study who had sinus rhythm and no history of atrial fibrillation were recruited between 1987 and 2001. Among those, 2,000 underwent bariatric surgery and 2,021 matched control subjects with obesity received usual care. During a median follow-up of 19 years, first-time atrial fibrillation occurred in 247 patients (12.4%) in the surgical group and in 340 (16.8%) control subjects. The risk of developing atrial fibrillation was 29% lower in the surgery group versus the control group. Younger individuals benefited more from surgical intervention. Moreover, those with a high diastolic blood pressure benefitted more from surgery compared to those with a low diastolic blood pressure.


Long-Term Protective Changes in Adipose Tissue After Gastric Bypass (Diabetes Care)

To investigate whether protection against the relapse or development of Type 2 diabetes after bariatric surgery involves beneficial changes in adipose function, data was collected on 49 women with obesity before, and 2 and 5 years after LRYGB. Clinical parameters and fine-needle biopsies from subcutaneous abdominal adipose tissue were obtained. From the biopsies, fat cell size and number, lipolysis, adiponectin and pro-inflammatory protein secretion were determined. After 2 years, BMI decreased from 43 to 29, which was accompanied by improvements in insulin sensitivity (HOMA of insulin resistance [HOMA-IR]), increased circulating and adipose secreted adiponectin, and decreased adipose lipolysis and fat cell size. Between 2 and 5 years after surgery BMI had increased to 31. This was associated with slightly increased HOMA-IR and unaltered circulating or adipose secreted adiponectin, but increased lipolysis and number of fat cells. At the 5-year follow-up, 30 subjects were pair-matched for BMI and age to 30 control women. All parameters, except lipolysis, were significantly more favorable in the surgery group compared with the matched control subjects. Moreover, in the surgery group the relationship between HOMA-IR and circulating adiponectin was less steep than in the controls. The findings revealed that LRYGB improves long-term insulin sensitivity and adipose phenotypes beyond the control state despite weight regain. The investigators hypothesized that postoperative beneficial alterations in adipose function may be involved in the diabetes-protective effect of bariatric surgery.


Predictors of Inadequate Weight Loss After Laparoscopic Gastric Bypass for Morbid Obesity (Obesity Surgery)

Data on 227 patients (mean age=48.6; mean BMI=53.6) who underwent primary LRYGB between September 2009 and March 2013 was collected prospectively to identify factors predictive of inadequate excess weight loss (EWL) at 12 months, which for the study was defined as < 50% EWL. Factors examined included age, gender, baseline BMI, preoperative EWL, length of time between initial consultation and surgery (TtS), presence of diabetes mellitus, arthritis, obstructive sleep apnea (OSA) and postoperative length of hospital stay (LOS). Stepwise regression analyses were used to estimate individual contributions of independent variables to the variance in EWL. Findings demonstrated inadequate EWL at 12 months to be predicted by older age (>60 years), patients with diabetes, higher baseline BMI (>60), those who gained weight preoperatively and waiting longer than 18 months for surgery from the time of initial consultation. Conversely, there was a significant positive association between preoperative EWL and that at 12 months. There was no effect of gender, arthritis or LOS on EWL at 12 months.


Gastro-Esophageal Reflux Disease and Barrett’s Esophagus After Laparoscopic Sleeve Gastrectomy: A Possible, Underestimated Long-Term Complication (SOARD)

Data on 162 patients who underwent primary sleeve gastrectomy from July 2007 to January 2010 was used to evaluate the incidence of gastro-esophageal reflux disease (GERD) following surgery. Preoperatively all patients underwent evaluation of GERD symptoms, proton pump inhibitors (PPIs) consumption recording and esophagogastroduodenoscopy (EGD). Three patients experienced major post-operative complications and as a results were excluded from the study. At a mean 58 months follow-up, incidence of GERD symptoms and PPI intake significantly increased when compared to pre-operative values (GERD: 68.1% vs 33.6%; PPI: 57.2% vs 19.1%). At EGD an upward migration of the “Z” line and a biliary-like esophageal reflux was found in 73.6% and 74.5% of cases respectively. A significant increase both in the incidence and in the severity of erosive esophagitis (EE) was evidenced, while non-dysplastic Barrett’s esophagus (BE) was newly diagnosed in 19 patients (17.2%). In the study the incidence of EE and of BE in sleeve gastrectomy patients was considerably higher than that reported in literature and it was not related to GERD symptoms. The authors concluded that endoscopic surveillance after sleeve gastrectomy should be advocated irrespective of the presence of GERD symptoms.


Family Factors that Characterize Adolescents with Severe Obesity and Their Role in Weight Loss Surgery Outcomes (Obesity)

Prospective data from 138 adolescents undergoing bariatric surgery (mean age = 16.9; mean BMI= 51.5 kg/m2) and their primary caregivers (mean age = 44.5; 93% female) was collected at pre-surgery/baseline and at 1 and 2 years post-surgery to assess whether family factors impact weight loss outcomes following surgery. Findings were compared to a control group of 83 nonsurgical adolescents and their respective caregivers (adolescents: mean age = 16.1; mean BMI = 46.9 kg/m2; caregivers: mean age = 43.9; 94% female). The majority (77.3%) of caregivers had obesity, with rates of caregiver who had undergone weight loss surgery significantly higher in the surgery cohort (23.8%) versus non-surgery group (3.75). Family dysfunction was prevalent, with rates higher for non-surgery group than the surgery group. For the surgery group, preoperative family factors (i.e., caregiver BMI or weight loss surgery history, dysfunction, social support) were not significant predictors of adolescent weight loss at 1 and 2 years postoperatively. However, change in family communication and emotional climate over time emerged as potential targets to optimize weight loss outcomes.