Healthcare Services, Vascular Center at Union Hospital, Dover Ohio
Vascular Center Physicians and Staff, Union Hospital Dover Ohio

Vascular Center Physicians & Staff

Dr. Jeffrey T. Prem serves as Union Hospital's Vascular Center Medical Director. In addition, our staff includes board-certified physicians and several full-time vascular technologists. All technologists hold at least a bachelor's degree and have been trained in vascular diagnostics by registered vascular technicians and the vascular surgeons at Union Hospital.


Dr. Jeffrey Prem, Vascular Surgeon, Union Hospital Dover Ohio Dr. Jeffrey T. Prem, MD, FACS, RPVI
Vascular Center Medical Director

Board Certified: American Board of Surgeons, American Board of Vascular Surgery; Registered Physician in Vascular Interpretation

Residency: Wright State University, Dayton, OH

Medical School: Wright State University, School of Medicine, Dayton, OH

Vascular Fellowship: North Shore Long Island Jewish Health, New York University School of Medicine

M. Todd Miller, M.D. Vascular Surgeon, Union Hospital Dover Ohio M. Todd Miller, M.D., RVT, RPVI
General and Vascular Surgery

Board Certified: American Board of Surgery and American Board of Vascular Surgery

Residency: Lehigh Valley Hospital

Medical School: The Ohio State University College of Medicine

Vascular Fellowship: The Toledo Hospital, Jobst Vascular Center

Dr. Jeffrey Prem, Vascular Surgeon, Union Hospital Dover Ohio Joseph N. Zemis, M.D., RVT, RPVI
General and Vascular Surgery

Board Certified: American Board of Surgery

Residency: Wright State University School of Medicine, Dayton, OH

Medical School: Emory University School of Medicine, Atlanta, GA

Dr. Jeffrey Prem, Vascular Surgeon, Union Hospital Dover Ohio Alok Bhagat, M.D.
Neurology/Sleep Medicine

Board Certified: American Board of Neurology, American Board of Sleep Medicine, Board of Clinical Neurophysiology

Residency: University of Kentucky Medical Center; VA Medical Center, KY

Medical School: Rajendra Medical College, India


Gary A. Crowthers, Vascular Center Union Hospital Dover Ohio Gary A. Crowthers, RCP
Director of Cardiopulmonary Services

Gary graduated from Green & Kellogg and University Buffalo School in Respiratory Care and has completed additional clinical and management graduate studies. He is a Licensed Respiratory Care Practitioner with over 40 years of health care management experience. As Director of Cardiopulmonary Services at Union Hospital, Gary has developed the departments of Respiratory Care, Cardiac and Pulmonary Rehabilitation, Sleep Center, Cardiology, and the Vascular Lab. He is a native of Tuscarawas County and currently resides in Brightwood.

Chris Beck, Vascular Center Union Hospital Dover Ohio Chris Beck, MBA, BAS, RVT
Manager of the Vascular Lab and Cardiopulmonary Rehabilitation

Chris holds his Master's Degree in Business Administration, his Bachelor's Degree in Sports Science, and is a Registered Vascular Technician. He has also earned Black Belt Certification in Lean and Six Sigma quality and statistical methods. Chris has been with Union Hospital since 2000. He is a member of the Society of Vascular Ultrasound, the Northern Ohio Vascular Association, the American Association of Cardiovascular and Pulmonary Rehabilitation and Leadership Tuscarawas. He and his family reside in Strasburg.

Jeffrey Miller, Vascular Center Union Hospital Dover Ohio Jeffrey Miller, BA, RVT
Senior Vascular Sonographer

Jeff holds his Bachelor's Degree in Community Health Education from Malone College and was inducted into Eta Sigma Gamma, a national health honorary society. He previously worked with communicable and infectious disease management before specializing in vascular ultrasound. Jeff is a Registered Vascular Technician and has been with Union Hospital since 2004. He currently resides in Dover.

Mark Lancaster, Jr. Vascular Center Union Hospital Dover Ohio Mark Lancaster Jr., BS, RVT
Senior Vascular Sonographer

Mark holds his Bachelor of Science Degree from the University of Toledo where he graduated Cum Laude and served as Vice President of Pi Kappa Phi.  He is a Registered Vascular Technician and has been with Union Hospital since 2004. Mark currently resides in Strasburg.

Courtney Karrenbauer, Vascular Center Union Hospital Dover Ohio Courtney Karrenbauer, MPH, BS, RVT
Vascular Sonographer

Courtney holds her Bachelor’s of Science degree in Health Education from Malone College where she graduated Cum Laude and was chosen as the Outstanding Health Educator of the Year.  She also holds her Master of Public Health degree from West Virginia University. Courtney worked as an Epidemiologist and Health Educator prior to specializing in Vascular Ultrasound at Union Hospital in 2006.  She is also licensed by the Ohio Department of Education as a Health Educator.  Courtney and her family currently reside in Massillon.

Blake Miller Vascular Center Union Hospital Dover Ohio Blake Miller, BA
Vascular Sonographer

Blake holds his Bachelor's Degree in Community Health Education from Malone College. Blake previously interned at Union Hospital's Vascular Center and has specialized in Vascular Diagnostics. Blake is a Registered Vascular Technician and resides in New Philadelphia.

Tara Stahl, Vascular Center Union Hospital Dover Ohio Tara Stahl, BRIT
Vascular Sonographer

Tara holds her Bachelor's of Radiologic and Imaging Sciences Technology degree with a concentration in Diagnostic Medical Sonography from Kent State University where she graduated Magna Cum Laude. Her final clinical rotation included Vascular Sonography, which was done at Union Hospital's Vascular Center. Tara resides in Dover.