Orepheus M. Hamilton is a Nurse Practitioner in the Department of Surgery at the University of Texas Medical Branch in Galveston, TX. She is board certified by the American Academy of Nurse Practitioners (AANP) and is licensed by the Texas Board of Nursing. As a member of the UTMB Department of Surgery, Ms. Hamilton works in the areas of colorectal and general surgery.

Ms. Hamilton completed her Bachelor of Science in Nursing in 2012 at the Chamberlain College of Nursing in Downers Grove, IL. She went on to complete the Adult/Gerontology Primary Care Nurse Practitioner (AGPCNP) program in 2015 at the Maryville University in St. Louis, MO. As an AGPCNP student, she performed clinical rotations at Memorial Hermann-Southeast in Houston, TX.

Ms. Hamilton has over 17 years of nursing experience and is also a member of the American Nurses Association, District TX09.

Dr. Pamela Daher received her MD from the Ichan School of Medicine at Mount Sinai in New York City, New York. She subsequently completed her general surgery residency at the Dell Medical School at the University of Texas Austin, and her colon and rectal surgery residency at Baylor Scott and White Medical Center in Dallas, TX before joining the faculty of UTMB.

Her clinical interests are cancer (colon, rectal, anal), surgical management of diverticular disease and its complications, inflammatory bowel diseases (Crohn’s, Ulcerative Colitis), benign anorectal disease (hemorrhoids, fistulas, fissures, pilonidal disease), rectal prolapse, surgical treatment of functional and mechanical bowel motility and continence disorders.

Dr. Uma R. Phatak is an Assistant Professor and Section Chief of Colon and Rectal Surgery in the Department of Surgery at the University of Texas Medical Branch (UTMB) in Galveston, Texas. She is board certified by the American Board of Surgery and the American Board of Colon and Rectal Surgery.

Dr. Phatak obtained her medical degree at New Jersey Medical School in Newark, New Jersey, in 2009. She went on to begin her general surgery resident training at the University of Texas Health Science Center (UTHSC) in Houston, Texas, in 2009.

After her second year of residency in 2011, Dr. Phatak was accepted to be a clinical research fellow in the Center for Surgical Trials and Evidence-Based Practice at UTHSC. Upon completing her fellowship in 2013, she earned her Master of Science in Clinical Research from UTHSC. She then continued her general surgery resident training at UTHSC, which she completed in 2016. She did a fellowship in Colon and Rectal Surgery at the University of Massachusetts in Worcester, Massachusetts, from 2016-2017.

In 2017, Dr. Phatak became an Assistant Professor in Colon and Rectal Surgery at Boston University Medical Center in Boston, Massachusetts. A year later, she became the Clerkship Site Director for MS3 Colorectal Surgery Rotation where she taught medical students.

Dr. Phatak joined UTMB in 2020. She is a member of several national scientific societies in surgery, has authored over 15 peer-reviewed articles in scientific journals and three book chapters, and is a journal reviewer for three scientific journals.

Dr. J. Patrick Walker is a Professor in the MIS/Foregut Surgery Division in the Department of Surgery at the University of Texas Medical Branch, Galveston, Texas. Dr. Walker holds the James C. Thompson, MD, Distinguished Chair in Surgery, is Vice Chair for Surgical Operations and is Surgical Director of Perioperative Services.

He completed his internship and residency at the University of Texas Medical Branch where he became Chief Resident. He earned his Bachelor of Science in Biology and his Bachelor of Arts in Chemistry at Southern Methodist University in Dallas, Texas. Dr. Walker earned his MD at the University of Texas Medical Branch.

Dr. Walker is a member of the Southern Surgical Association, the Texas Surgical Society, the Texas Medical Association, and the American College of Surgeons. He is a past Director of the American Board of Surgery and a current Governor of the American College of Surgeons. He has been honored with the Ashbel Smith Distinguished Alumni Award at the University of Texas Medical Branch and the Arthur Ellenberger Award from the American College of Surgeons.

Dr. Walker's special interests include surgical education, rural/community surgery, endoscopy, acute care surgery, evaluation of abdominal complaints, gall bladder disease, hernias, colorectal surgery and complex surgical problems.

Dr. Anthony D’Andrea is an Assistant Professor in the Section of Colon and Rectal Surgery, Department of Surgery, at the University of Texas Medical Branch (UTMB) in Galveston, Texas. He grew up in Houston, and received a Bachelor in Business Administration at Baylor University in Waco, Texas. He then went on to the University of Miami Miller School of Medicine where he graduated with a dual Doctor of Medicine (MD) and Master of Public Health (MPH). As a medical student he was inducted into the Alpha Omega Alpha National Medical Honor Society. He completed residency training in surgery at the Mount Sinai Hospital in New York City and fellowship training in colon and rectal surgery at the Cleveland Clinic in Weston, Florida.

Dr. D’Andrea’s training in colorectal surgery is longstanding. Prior to medical school, he worked as a clinical research associate at the Lankenau Medical Center in Wynnewood, Pennsylvania, under the guidance of Dr. John Marks. His research focused on minimally invasive laparoscopic colorectal surgery featuring radical sphincter preservation for rectal cancer after neoadjuvant chemoradiation. During medical school at the University of Miami, Dr. D’Andrea’s public health work involved the study of colorectal cancer survivorship and improving patients’ quality of life after treatment. In general surgery residency at the Mount Sinai Hospital, he spent a dedicated year of research under the mentorship of Dr. Patricia Sylla where he focused on minimally invasive laparoscopy, robotic surgery, and transanal endoscopic surgery for rectal cancer, as well as Crohn’s disease, and ulcerative colitis. Dr. D’Andrea’s training culminated at the Cleveland Clinic Florida where he had the opportunity to learn from longtime leaders in the field of colorectal surgery. Dr. D’Andrea is now privileged to return to Texas joining the faculty at UTMB where he can help serve the health and population of his home state with the highest quality of care.