Vascular Surgery Staff Skip Menu Welcome Faculty Staff Residents Recently Graduated Residents Contact Us News Vascular Surgery Staff Enrique Barrientos, PA Physician Assistant Cardiovascular and Thoracic Surgery Christina Guarin, MSN, APRN, ACNPC-AG Nurse Practitioner Valarie Zimmerman Administrative CoordinatorPhone: (409) 772-6366 Cheryl Kernan Coordinator II - Residency Training ProgramPhone: (409) 772-8128