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Updated: Apr 15, 2026

Roux-en-Y Gastric Bypass Operation in Rats
Published on: June 11, 2012
Roux-en-Y gastric bypass is associated with an increased exposure to ionizing radiation
Peter Nau1, George Molina2, Aran Shima2
1The University of Iowa Hospitals and Clinics, Iowa City, Iowa.
Background:
Bariatric surgery provides for a reliable and sustainable solution to the obesity epidemic. The gold standard bariatric surgical procedure is the Roux-en-Y gastric bypass (RYGB). Assessment of this population preoperatively and work-up of postoperative complications often includes radiographic evaluation. Repeated exposure to radiation is not without complication.
Objective:
Assess the association between the RYGB and exposure to ionizing radiation.
Setting:
Academic medical center.
Methods:
Patients were identified by their ICD-9 code as having had a RYGB at the Massachusetts General Hospital (MGH) from 2002 to 2012. The number of abdominal and pelvis (A/P) computed tomography (CT) scans performed was determined and converted into an effective dose (ED) and expressed as milliSeiverts (mSv) to illustrate the biologic effects of radiation.
Results:
From 2002 to 2012, 1789 primary laparoscopic RYGBs were completed. Fifty-five revisional operations were completed on 51 patients. Of these, 38 had both their index and second operation at the MGH. A total of 1065 A/P CTs were completed in the laparoscopic RYGB population (mean = .6), and 106 A/P CTs were done in the revisional surgery cohort (mean = 2.8). The mean ED of radiation was 56.1 mSv and 19.5 mSv for the index and revisional populations, respectively.
Conclusions:
This study demonstrated the significant cumulative radiation exposure attributable to A/P CTs. This exposes the patient to a potential increased risk of malignancy as well as imposing a financial burden on the healthcare system. The findings of this study raise the awareness of an increased risk of radiation exposure for this population and the necessity of creation of a dedicated algorithm for the mindful utilization of CT imaging.

