Meet Our Team

Bariatrics faculty photo

Read About Our Team Members

Andres Castellanos, MD, FACS, Medical Director

doctor andres castellanosAndres Castellanos, MD, is the director of the Center for Surgical Weight Loss at Hahnemann University Hospital, and assistant professor of surgery and associate surgical program director for Drexel University College of Medicine.  With clinical expertise in laparoscopic and bariatric surgeries, his research as focused on the use of laparoscopic tools for robotically assistant minimally invasive surgeries - the future of robotic surgeries and gastro-intestinal surgeries in obese patients.

Dr. Castellanos is a board-certified general surgeon, who received his Medical Doctor degree from the University of Zulia Medical School in Venezuela.  He completed a surgery internship and residency at the Medical College of Pennsylvania Hospital, and research fellowships in minimally invasive surgery and robotics at Drexel University College of Medicine.   He is a member of the Pennsylvania Medical Society, the American Medical Association, and the Society of American Gastrointestinal Endoscopic Surgeons.  Dr. Castellanos is also a member of the American Society for Metabolic and Bariatric Surgery, Society of Laparoscopic Surgery and the Minimally Invasive and Robotic Surgery Association.

Elizabeth Renza-Stingone, MD, FACS

doctor elizabeth renza-stingoneElizabeth Renza-Stingone, MD is a board-certified General Surgeon and a Fellow of the American College of Surgeons.  Dr. Renza graduated from New York Medical College in 2000.  After completing a residency program in General Surgery at Westchester Medical Center/New York Medical College in 2006, she served in the United States Army as a general surgeon for four years.  She completed a tour of duty in Afghanistan in 2007 as part of Operation Enduring Freedom. After her military service, Dr. Renza completed a one-year Fellowship in Minimally Invasive and Bariatric Surgery at New York Medical College.  During this advanced training, she developed a strong interest in Weight Loss Surgery.  She has spent the last four years working to assist with the development of the Weight Loss Surgery Program at Aria Health in Northeast Philadelphia and Bucks County and is joining the Bariatric Team at Hahnemann University Hospital full-time in June 2015.  She is an Assistant Professor of Surgery at Drexel University College of Medicine.

Dr. Renza’s surgical and professional expertise include laparoscopic bariatric operations (bypass and sleeve gastrectomy), foregut surgeries (anti-reflux procedures, hiatal hernia, and paraesophageal hernia), laparoscopic herniorrhaphy, and minimally invasive surgeries performed with the DaVinci Robotic system. 

Carolynn Nutter, Program Manager

Program Manager NutterCarolynn Nutter is a cum laude graduate of Drexel University, and has a Bachelor of Science in Communications and Applied Technology.  Carolynn has served as program manager for the Center for Surgical Weight Loss since 2008, and has the responsibility for the design and implementation of the Center's services.

Carolynn's experience includes strategic planning, marketing, resource management, and process improvement.  She has spent more than 20 years in the health care arena, and is currently pursuing a Master’s degree at Drexel University.

Roldana Huganir, RDN, LDN, Program Nutritionist

Program Nutritionist HuganirRoldana Huganir is a graduate of Purdue University, and has a Bachelor of Science in Nutrition/Dietetics. She completed her dietetic internship with Southern Regional Medical Center in Atlanta, Georgia.  Roldana previously worked as a Supermarket Dietitian for one of the largest grocery chains in the United States.  She also has past experience as an assistant chef for a specialty cafe. 

Roldana's experience includes weight loss counseling and behavior modification, diabetes, hypertension, and cardiovascular disease.  As a Registered Dietitian Nutritionist, Roldana's goal is to help people take charge of their health through sound nutrition.  Assisting patients with setting goals and tracking program and outcomes is how Roldana supports patients on their journey to surgery and beyond. 

Mary Ellen Volb, BSN, RN, Clinical Nurse Coordinator

Clinical Nurse Mary Ellen Volb, BSN, RN is a summa cum laude graduate of LaSalle University.  She has extensive knowledge of all aspects of bariatric surgery, and is proficient in caring for medically complex patients.  

Prior to joining the Center for Surgical Weight Loss, Mary Ellen served as a clinical coordinator at another local bariatric surgery clinic.

Patricia Genao, Certified Medical Assistant

Patricia genaoPatricia is the newest member of the Bariatric Surgery team at Hahnemann.  In her role as medical assistant, she is responsible for patient throughput activities.  Patricia earned her medical assistant certification in 2004.  Before joining the Hahnemann team, Patricia served as a medical assistant at several hospitals, in both New York and Philadelphia.  Patricia is bilingual; she is fluent in both English and Spanish, and provides translation for the bariatric surgery team and patients. 

Shikisha Williams, Operations Coordinator

Shikisha williamsShikisha Williams ("Shi," as she is known to the team) serves as the team’s operations coordinator.  She manages all front-desk operations, and is the program’s first line of communication.  “Shi” has more than 20 years' experience providing administrative support.  Prior to joining the Center for Surgical Weight Loss team, she served as the Administrative Assistant for Hahnemann's Human Resources Department.

Hahnemann bariatrics

  231 N. Broad Street, 3rd Floor, Philadelphia, PA 19107
or visit us at our new site located at
2813 Cottman Avenue, Philadelphia, PA 19149

Call (267) 330-0760 or email us for more information!