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Daniel Moritz Felsenreich
Dr. scient. med. Daniel Moritz Felsenreich, MD

Department of General Surgery (Division of Visceral Surgery)
Position: Research Associate (Postdoc)

ORCID: 0000-0002-5229-5096
T +43 1 40400 56220


Anastomosis, Roux-en-Y; Bariatric Medicine; Bariatric Surgery; Bariatrics; Bile Reflux; Gastric Bypass; Gastroesophageal Reflux

Research interests

As a member of Univ. Doz. Dr. Gerhard Prager’s team for metabolic and bariatric surgery I have specialized in doing research on Sleeve gastrectomy, Omega Loop gastric bypass, as well as the treatment of weight regain after Roux-en-Y gastric bypass. My long-term study of Sleeve gastrectomy focusses reflux, weight regain, and quality of life. With my RCT on Omega Loop gastric bypass I aim at revealing the impact of anti-reflux sutures on biliary reflux after the procedure. I am also studying the outcome of different methods of treating weight regain (e.g. pouch resizing and banding) after Roux-en-Y gastric bypass.

Techniques, methods & infrastructure

  • Retrospective database analyses
  • Prospective clinical trials


  • Prospective, randomized, controlled trial of Omega Loop Gastric Bypass with and without anti-reflux sutures – a pilot study (2017)
    Source of Funding: Medical Scientific Fund of the Mayor of the City of Vienna,
    Principal Investigator

Selected publications

  1. Felsenreich, D.M. et al., 2019. Surgical therapy of weight regain after Roux-en-Y gastric bypass. Surgery for Obesity and Related Diseases, 15(10), pp.1719–1728. Available at:
  2. Felsenreich, D.M. et al., 2017. Reflux, Sleeve Dilation, and Barrett’s Esophagus after Laparoscopic Sleeve Gastrectomy: Long-Term Follow-Up. Obesity Surgery, 27(12), pp.3092–3101. Available at:
  3. Felsenreich, D.M. et al., 2019. Quality of Life 10 Years after Sleeve Gastrectomy: A Multicenter Study. Obesity Facts, pp.157–166. Available at:
  4. Felsenreich, D.M. et al., 2018. Update: 10 Years of Sleeve Gastrectomy—the First 103 Patients. Obesity Surgery, 28(11), pp.3586–3594. Available at:
  5. Felsenreich, D.M. et al., 2019. Roux-en-Y Gastric Bypass as a Treatment for Barrett’sEsophagus after Sleeve Gastrectomy. Obesity Surgery. Available at: