About Us

Our Board-Certified physicians offer a wide range of diagnostic and urologic treatment options. We look forward to helping manage your urological healthcare needs.

Our Health Care Providers

Christopher M. Cassisi, M.D.

Dr. Cassisi is a certified Diplomat of the American Board of Urology. Dr. Cassisi is a Gainesville native and a graduate of Oak Hall High School. He received his undergraduate degree at the University of Florida and his medical education at the University of Florida. He completed his surgical and urological residencies at the University of Florida-Shands Hospital. Dr. Cassisi is an avid fan of the Florida Gators. He enjoys collecting antique cars and spending time with his children.

Daryll B. Bullen, M.D.

Dr. Bullen is from Greenville, South Carolina. He earned his Medical Degree from the Univeristy of Tennesse, Memphis after receiving his Bachelor of Science degree from Furman University. He completed his internship and residency in Surgery and Urology at the University of Tennessee College of Medicine in Memphis. He is a member of the American Urological Association and a Diplomat of the American Board of Urology. Dr. Bullen enjoys spending time with his family, pets and gardening.

Angela K. Santiago, ARNP, FNP-BC

Angi was raised in Sarasota, Florida and went to undergrad at Covenant College in Lookout Mountain, Georgia where she received her BA in Sociology. She then received her AS in nursing from SFCC in Gainesville in 2004 and received her BSN and MSN at the University of Florida in 2006. She is a board-certified Family Nurse Practitioner with national certification with ANCC. She has experience in Cardiology, Neurosurgery, and has been practicing Urology since 2013. Angi enjoys the outdoors with gardening, boating, traveling, and spending time with her family.

Brandon Rosario, PA

Brandon is a recent graduate of the Florida State University Physician Assistant Program. His journey in medicine began at a young age when he was volunteering at Nicklaus Children’s Hospital. He has carried that passion to outreach programs at the University of Florida during his undergraduate studies. A goal of his is to break down language barriers within the medical community as he hopes to become a bilingual PA after attending an immersion program at Middleburg College. On his days off, you will see him hopping on a plane and exploring new places with his friends! When he is not traveling, he enjoys reading books on new advances in medicine or trying new restaurants.