Gastrointestinal Surgery

Ronald P. DeMatteo, MD, FACSRonald P. DeMatteo, MD, FACS

Endocrine and Oncologic Surgery

Chair, Department of Surgery

John Rhea Barton Professor of Surgery

Dr. DeMatteo is the Chairman of the Department of Surgery and a Surgical Oncologist who specializes in treating diseases of the liver, bile duct, gallbladder, pancreas, and abdominal sarcomas (GIST). His clinical research has focused on liver, bile duct, gallbladder, and pancreas cancers. In addition, he has led several national trials testing the benefit of imatinib mesylate (Gleevec) following surgery for gastrointestinal stromal tumor (GIST), a tumor that usually begins in the stomach or intestine. In the laboratory he and his colleagues study the immune environment of the liver and tumor immunology, working to develop immune therapies to help prevent tumors from returning after surgery.


Douglas L. Fraker, MDDouglas L. Fraker, MD

Endocrine and Oncologic Surgery

Chief, Division of Endocrine and Oncologic Surgery

Professor of Surgery



Major Kenneth Lee, IV, MD, PhDMajor Kenneth Lee, IV, MD, PhD

Gastrointestinal Surgery

Associate Professor of Clinical Surgery



Charles M. Vollmer, MD

Gastrointestinal SurgeryCharles M. Vollmer, MD

Chief, Division of Gastrointestinal Surgery at Penn Medicine

Director, Pancreatic Surgery

Co-Director, Penn Pancreatic Cyst Multidisciplinary Program

Professor of Surgery at the Hospital of the University of Pennsylvania

Dr. Vollmer is an internationally renowned specialist in pancreatic surgery. He treats all facets of pancreatic pathologies including cancer, neuroendocrine tumors, precancerous cysts (including IPMN), and pancreatitis. His highly-cited research focuses on technical aspects of pancreatic surgery and outcomes that ensue, with a particular emphasis on the most troublesome complication - pancreatic fistula. He also conducts translational research in association with scientists at the Perelman School of Medicine focused on the detection capabilities of “liquid biopsy” in patients with pancreatic cancer. In addition to authoring over 200 peer-reviewed scientific articles, 30 book chapters, and 3 textbooks, he has served in numerous leadership roles in national and international surgical societies, including the AHPBA (former President) and the IHPBA (Current Treasurer).

Robert E. Roses, MDRobert E. Roses, MD

Endocrine and Oncologic Surgery

Associate Professor of Surgery at the Hospital of the University of Pennsylvania