(Boston, MA) - Research from the Harvard Pilgrim Health Care Institute finds that gastric bypass is associated with a higher risk of additional operations or other invasive procedures, compared to a gastric sleeve procedure.  The study, “Risk of Operative and Nonoperative Interventions Up to 4 Years After Roux-en-Y Gastric Bypass vs Vertical Sleeve Gastrectomy in a National US Commercial Insurance Claims Database,” appears online December 18 in JAMA