Test Characteristics of Abdominal Computed Tomography for the Diagnosis of Gastro-gastric Fistula in Patients with Roux-en-Y Gastric Bypass



Gastrogastric fistulae (GGF) occur in 1–6% of Roux-en-Y gastric bypass (RYGB) patients. Many patients undergo abdominal computed tomography (CT) as an initial test owing to its wide availability; however, CT diagnostic accuracy for GGF is unclear. Our aim was to evaluate test characteristics of abdominal CT compared to upper gastrointestinal series (UGI) and esophagogastroduodenoscopy (EGD) for diagnosing GGF using surgery as a gold standard.


Retrospective review of RYGB patients who underwent abdominal CT with oral contrast within 1 year. Demographics, weight parameters, and symptoms were collected. Surgery within 1 year of the diagnostic tests was included as the gold standard comparison. Primary outcomes included CT sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and diagnostic accuracy (DA) for GGF.


One hundred thirty-seven patients were included, where 42 (30.1%) had positive CT and 95 (69.3%) had negative CT for GGF. Compared to surgical confirmation, CT abdomen with PO contrast had sensitivity of 73.1% (59–84.4), specificity of 95.2% (88.3–98.7), PPV 90.5% (77.4–97.3), NPV of 85.1% (76.3–91.2), and DA 89.7%. UGI series had sensitivity of 58.5% (42.1–73.7), specificity of 98.8% (93.5–99.9), PPV of 96% (79.7–99.9), NPV of 82.8% (73.9–89.7), and diagnostic accuracy (DA) of 85.4%. EGD had sensitivity of 78.3% (63.6–89.1), specificity of 98.8% (93.5–99.9), PPV 97.3 (85.8–99.9), and DA 91.5%. There were no significant differences in diagnostic test characteristics among modalities.


Abdominal CT with oral contrast has similar diagnostic test characteristics to UGI and EGD at detecting GGF when using surgical diagnosis as a gold standard.

This is a preview of subscription content, access via your institution.


  1. 1.

    Griffith PS, Birch DW, Sharma AM, et al. Managing complications associated with laparoscopic Roux-en-Y gastric bypass for morbid obesity. Can J Surg. 2012;55(5):329–36. https://doi.org/10.1503/cjs.002011.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  2. 2.

    Lager CJ, Esfandiari NH, Luo Y, et al. Metabolic parameters, weight loss, and comorbidities 4 years after Roux-en-Y gastric bypass and sleeve gastrectomy. Obes Surg. 2018;28(11):3415–23. https://doi.org/10.1007/s11695-018-3346-1.

    Article  PubMed  Google Scholar 

  3. 3.

    Hayoz C, Hermann T, Raptis DA, et al. Comparison of metabolic outcomes in patients undergoing laparoscopic Roux-en-Y gastric bypass versus sleeve gastrectomy - a systematic review and meta-analysis of randomised controlled trials. Swiss Med Wkly. 2018;148:w14633. https://doi.org/10.4414/smw.2018.14633.

    CAS  Article  PubMed  Google Scholar 

  4. 4.

    Chahine E, Kassir R, Dirani M, et al. Surgical management of gastrogastric fistula after Roux-en-Y gastric bypass: 10-year experience. Obes Surg. 2018;28(4):939–44. https://doi.org/10.1007/s11695-017-2949-2.

    Article  PubMed  Google Scholar 

  5. 5.

    Gumbs AA, Duffy AJ, Bell RL. Management of gastrogastric fistula after laparoscopic Roux-en-Y gastric bypass. Surg Obes Relat Dis. 2006;2(2):117–21. https://doi.org/10.1016/j.soard.2005.12.002.

    Article  PubMed  Google Scholar 

  6. 6.

    Salimath J, Rosenthal RJ, Szomstein S. Laparoscopic remnant gastrectomy as a novel approach for treatment of gastrogastric fistula. Surg Endosc. 2009;23(11):2591–5. https://doi.org/10.1007/s00464-009-0465-8.

    Article  PubMed  Google Scholar 

  7. 7.

    Carrodeguas L, Szomstein S, Soto F, et al. Management of gastrogastric fistulas after divided Roux-en-Y gastric bypass surgery for morbid obesity: analysis of 1,292 consecutive patients and review of literature. Surg Obes Relat Dis. 2005;1(5):467–74. https://doi.org/10.1016/j.soard.2005.07.003.

    Article  PubMed  Google Scholar 

  8. 8.

    Pauli EM, Beshir H, Mathew A. Gastrogastric fistulae following gastric bypass surgery-clinical recognition and treatment. Curr Gastroenterol Rep. 2014;16(9):405. https://doi.org/10.1007/s11894-014-0405-1.

    Article  PubMed  Google Scholar 

  9. 9.

    Cucchi SG, Pories WJ, MacDonald KG, et al. Gastrogastric fistulas. A complication of divided gastric bypass surgery. Ann Surg. 1995;221(4):387–91. https://doi.org/10.1097/00000658-199504000-00009.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  10. 10.

    Filho AJB, Kondo W, Nassif LS, et al. Gastrogastric fistula: a possible complication of Roux-en-Y gastric bypass. J Soc Laparoendosc Surg. 2006;10(3):326–31.

    Google Scholar 

  11. 11.

    Stanczyk M, Deveney CW, Traxler SA, et al. Gastro-gastric fistula in the era of divided Roux-en-Y gastric bypass: strategies for prevention, diagnosis, and management. Obes Surg. 2006;16(3):359–64. https://doi.org/10.1381/096089206776116426.

    Article  PubMed  Google Scholar 

  12. 12.

    Bhatt A, Yang X, Karnik N, et al. Use of computerized tomography in abdominal pain. Am Surg. 2018;84(6):1091–6.

    Article  Google Scholar 

  13. 13.

    Gao G, Nezami N, Mathur M, et al. Diagnosis of gastrogastric fistula on computed tomography: a quantitative approach. Abdom Radiol (NY). 2018;43(6):1329–33. https://doi.org/10.1007/s00261-017-1304-3.

    Article  Google Scholar 

  14. 14.

    Brenner H, Gefeller O. Variation of sensitivity, specificity, likelihood ratios and predictive values with disease prevalence. Stat Med. 1997;16(9):981–91.

    CAS  Article  Google Scholar 

  15. 15.

    Brethauer SA, Nfonsam V, Sherman V, et al. Endoscopy and upper gastrointestinal contrast studies are complementary in evaluation of weight regain after bariatric surgery. Surg Obes Relat Dis. 2006;2(6):643–8; discussion 9-50. https://doi.org/10.1016/j.soard.2006.07.012.

    Article  PubMed  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Christopher C. Thompson.

Ethics declarations

Ethics Approval and Consent to Participate

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of study, formal consent is not required. Informed consent does not apply.

Conflict of Interest

Russell D. Dolan, MD: No conflicts of interest to report.

Ahmad Najdat Bazarbashi, MD: No conflicts of interest to report.

Pichamol Jirapinyo, MD, MPH: Has the following disclosures: Apollo Endosurgery, Research Support; Fractyl, Research Support; GI Dynamics, Research Support; Endogastric Solutions, Consultant.

Christopher C. Thompson MD, MSc, AGAF, FACG, FASGE, FJGES: Has the following disclosures: Apollo Endosurgery, Consultant/Research Support (Consulting fees/Institutional Research Grants); Aspire Bariatrics, Research Support (Institutional Research Grant); BlueFlame Healthcare Venture Fund, General Partner; Boston Scientific, Consultant (Consulting fees); Covidien/Medtronic, Consultant (Consulting Fees); EnVision Endoscopy (Board Member); Fractyl, Consultant/Advisory Board Member (Consulting Fees); GI Dynamics, Consultant (Consulting Fees)/Research Support (Institutional Research Grant); GI Windows, Ownership interest; Olympus/Spiration, Consultant (Consulting Fees)/Research Support (Equipment Loans); Spatz, Research Support (Institutional Research Grant); USGI Medical, Consultant (Consulting Fees)/Advisory Board Member (Consulting fees)/Research Support (Research Grant).

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Guarantor of the article: Christopher C. Thompson MD, MSc, AGAF, FACG, FASGE, FJGES

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Dolan, R.D., Bazarbashi, A.N., Jirapinyo, P. et al. Test Characteristics of Abdominal Computed Tomography for the Diagnosis of Gastro-gastric Fistula in Patients with Roux-en-Y Gastric Bypass. OBES SURG (2021). https://doi.org/10.1007/s11695-021-05296-y

Download citation


  • Gastrogastric fistula
  • Roux-en-Y gastric bypass
  • Computed tomography