Sa1358 Endoscopic Ultrasound Follow up Study of Fluid Collections in Acute Necrotizing Pancreatitis: Are They Pseudocysts, Walled off Pancreatic Necrosis or Need a New Name?

Abstract

Purpose: The prevalence of obesity is increasing and the number of patients undergoing bariatric surgery is rising. There is no data on the risk factors for AP in this patient population. Methods: Using our historical cohort of post bariatric surgery patients, we performed a nested case-control study to identify risk factors for AP. The medical records of all patients who underwent bariatric surgery at our center from January 2004 to September 2011 were reviewed and patients who developed AP (ACG criteria) during follow-up were identified. The patients with AP had a mean age of 47.3 yrs, 21.7% were males and mean pre-op BMI was 47.4 kg/m2. For each case, two age, gender, and pre operative BMI-matched controls were selected. Univariable Cox regression analysis was performed to assess factors associated with the development of AP after bariatric surgery. Results: 28 patients with AP and 56 controls were included. Table 1 summarizes the results of the Cox regression analysis. The only baseline variable that predicted post-op AP was a prior history of AP. However, three other variables identified after surgery were associated with AP: 1. Rapid weight loss as measured by percent of excess weight loss (EWL) at the first post-op visit ( ,1 month). For every 1% increase in the EWL, the hazard of developing AP increased by 3%. 2. Abnormal findings on post-op ultrasound (US). Of the patients with AP, 13 (46%) had an abnormal finding (stones, sludge or ductal dilation) on right upper quadrant US, and 10 patients needed an intervention in the form of a cholecystectomy or an ERCP. 3. Post-op complications of bowel leak or anastomotic stricture. The type of bariatric surgery was not a risk factor for AP. Conclusions: Other than a past history of AP, no baseline risk factors were found to predict post-op AP. However, extremely rapid excess weight loss and the development of gallstones/sludge on US were predictive. Clinical implication: Screening patients with rapid EWL for stones and sludge using US and offering early intervention may prevent AP in this group. Further study into mechanisms, risk factors and preventive measures for AP in this population is warranted. Results of univariable analysis