Dr. Thomas Tielleman, M.D. is a therapeutic endoscopist and Assistant Professor in the Department of Internal Medicine at the University of Texas Southwestern Medical Center. He completed his GI fellowship and advanced endoscopy fellowship at UT Southwestern prior to joining as faculty in 2021. He is double board certified in Internal Medicine and Gastroenterology by the American Board of Internal Medicine.

Dr. Tielleman’s clinical focuses include multiple forms of therapeutic endoscopy treating a wide variety of ailments. He specializes in 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. 

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

Dr. Tielleman performs peroral endoscopy myotomy (POEM) to treat Achalasia, Zenker’s diverticulum, and Gastroparesis in a minimally invasive/non-surgical fashion. He has also 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 to allow for a minimally invasive way to entirely remove pre-cancerous lesions and early gastrointestinal cancers without the need to surgically remove the underlying organ.

Dr. Tielleman’s non-clinical focuses include developing simulation and hands-on endoscopy training for the UT Southwestern Gastroenterology fellowship as well as research on therapeutic endoscopy outcomes.

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