Meet Our Physicians

Meet The Physicians

Physicians associated with North Vista Hospital include:

Bernie Hanna, M.D.,
Medical Director

Dr. Hanna is a board-certified general surgeon who has performed bariatric surgery procedures in Southern Nevada for more than 10 years.

He completed his undergraduate work at Barry University in Miami and graduated from Howard University Medical School and its general surgery residency program.

In addition to his extensive experience performing weight loss surgeries, Dr. Hanna has served as a trauma surgeon, an assistant clinical professor and is a published medical researcher.

Dr. Hanna is a diplomate of the American Board of Surgeons, a member of The American Society for Metabolic and Bariatric Surgeons, the American College of Surgeons, the American Medical Association, the National Medical Association, the Nevada State Medical Association, Clark County Medical Society, the Association for the Advancement of Wound Care and the Society of Laparoendoscopic Surgeons.

Thomas Umbach, M.D.

Dr. Umbach is a bariatric surgeon whose entire practice is devoted to performing weight-loss surgeries.

Before relocating in Southern Nevada, Dr. Umbach started the laparoscopic surgical weight loss program at Kaiser Permanente South San Francisco and created a similar program in Eugene, Oregon, that earned accreditation as a center of excellence.

Dr. Umbach graduated from Virginia Commonwealth University School of Medicine, completed his residency at Kaiser Permanente in Los Angeles and was fellowship trained in advanced minimally invasive surgery at the University of Southern California.

He is a fellow of both the American Society of Metabolic and Bariatric Surgery and the American College of Surgeons. He is also a member of the American Board of Surgery.

Dr. Umbach, who is married with two children, enjoys traveling, camping and reading. He is also a licensed pilot who loves to fly when he can find the spare time.

Mustafa Ahmed, M.D. , FACS

Dr. Mustafa Ahmed graduated from Ohio State University College of Medicine and Public Health before doing an internal medicine residency at Mount Carmel Medical Center, Columbus Ohio.

Dr. Ahmed has certifications with the American Board of Surgery, Surgical Critical Care, Advanced Cardiac Life Support and Advanced Trauma Life Support.

The experience he had as an internist ultimately led him to finish with a Bariatric Fellowship. The most common denominator with patients who suffer from diabetes, high blood pressure, coronary artery disease, osteoarthritis, and other life debilitating diseases is often obesity. Dr. Ahmed believes that in order to treat and improve a patient's overall health you have to address the obesity.

Dr. Ahmed's practice is centered on patient care and empowering patients who suffer from Obesity. "Until we treat obesity, we can only chase the diseases that are associated with it."

On a personal note, he is married with five boys. One of the passions they have as a family is spending time together hiking, swimming, and playing soccer.

Francis Teng, M.D, FACS

Dr. Teng received his medical degree in 1991 from the University of NV School of Medicine, Reno, NV. He is a diplomat of the American Board of Surgeons, Society of Laparoendoscopic Surgeons Member, and a member of the American Society of Metabolic and Bariatric Surgeons.

Dr. Teng is board certified in general surgery and has been practicing bariatric surgery since 2002. He specializes in advanced laparoscopic procedures and general surgery.