Thomas Tielleman, M.D., is an Assistant Professor in the Department of Internal Medicine at UT Southwestern Medical Center. He is a therapeutic endoscopist.

Dr. Tielleman completed his gastroenterology fellowship and advanced endoscopy fellowship at UT Southwestern before joining as faculty in 2021. He is double board certified in internal medicine and gastroenterology by the American Board of Internal Medicine.

His areas of clinical focus include multiple forms of therapeutic endoscopy, treating a wide variety of ailments. He specializes in endoscopic retrograde cholangiopancreatography (ERCP) for complex pancreaticobiliary procedures as well as endoscopic ultrasound to assist with cancer diagnoses, minimally invasive drainage of abnormal fluid collections, and management of gastric varices.

Dr. Tielleman has undergone additional advanced training in the field of third space endoscopy, which includes peroral endoscopic myotomy (POEM) and endoscopic submucosal dissection (ESD).

He performs POEM to treat achalasia, Zenker’s diverticulum, and gastroparesis in a minimally invasive and nonsurgical fashion. He has undergone extensive training and proctorship with both American and Japanese masters in ESD, a procedure used to remove tumors from the gastrointestinal tract.

ESD was initially developed by the Japanese in the 1990s to remove early gastrointestinal cancers. Over time, the procedure has spread through Europe and now to North America, providing a minimally invasive way to entirely remove precancerous lesions and early gastrointestinal cancers without the need to surgically remove the underlying organ.

Dr. Tielleman’s areas of nonclinical focus include developing simulation and hands-on endoscopy training for the UT Southwestern Gastroenterology Fellowship as well as research into therapeutic endoscopy outcomes.

He is a member of the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy.

Education & Training
  • Medical School - UT Southwestern Medical School (2010-2014)
  • Residency - UT Southwestern Medical Center (2014-2017), Internal Medicine
  • Fellowship - UT Southwestern Medical Center (2017-2020), Gastroenterology
  • Fellowship - UT Southwestern Medical Center (2020-2021), Advanced Endoscopy
Professional Associations & Affiliations
  • American College of Gastroenterology
  • American Gastroenterological Association
  • American Society for Gastrointestinal Endoscopy
Honors & Awards
  • Lyman E. Bilhartz Faculty Teaching Award 2023, UT Southwestern Gastroenterology Fellowship
  • Gold Medal/1st Place 2022, American Society of Gastrointestinal Endoscopy World Cup of Endoscopy
  • Chief Fellow 2019-2020, UT Southwestern Gastroenterology Fellowship
  • Alpha Omega Alpha Honor Medical Society 2017, UT Southwestern Medical School
Books & Publications
  • Therapeutic endoscopy

Clinical Focus

  • Therapeutic endoscopy
  • Biliary disorders
  • Pancreatic Cancer Prevention

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