Skip to main content
Couple exercising outdoors

Meet the Bariatric Surgery Team

As a nationally recognized Bariatric Surgery Center of Excellence®, Sansum Clinic is here to help you make—and maintain—profound changes for lasting weight loss. From extensive pre-operative education, through ongoing follow-up support, count on personalized care every step of the way.

Get to know a little about our dedicated team here. Read bariatric patient testimonials. Then call (805) 898-3472 or RSVP for a free weight-loss surgery orientation, where we’ll walk through the different types of procedures we perform, and see if you may be a candidate.

Marc Zerey, MD, CM, MSc, FRCSC, FACS – Bariatric Surgeon

Dr. Marc Zerey, bariatric surgeon

Dr. Marc Zerey is a board-certified physician at Sansum Clinic specializing in bariatric surgery and advanced laparoscopic techniques. He performs minimally invasive primary and revisional weight loss surgery, including Roux-en-Y gastric bypass, sleeve gastrectomy and adjustable gastric banding. These procedures require just a few small incisions and often offer less pain and scarring, fewer complications and faster recovery.

In addition to bariatric surgery, Dr. Zerey performs minimally invasive procedures to treat hernias, heartburn, bowel conditions, disorders of the spleen and tumors of the stomach and adrenal gland, as well as complications of the gallbladder and bile ducts.

Dr. Zerey has published extensively, including journal articles in American Surgeon, American Journal of Surgery, Journal of Surgical Research, and Surgical Innovation. He is a frequent lecturer on surgical topics including weight loss surgery.

Joanna K. Buitrago, NP

Joanna Buitrago

Joanna Buitrago, MS, AG-PCNP, certified registered nurse and adult-gerontology primary care nurse practitioner graduated from Walden University in Baltimore, MD and joins our surgery team at Sansum Clinic. As a cardiac surgery ICU nurse at the University of Maryland Medical Center, Joanna was a nursing excellence award nominee.  

Christina Dominguez MS, RD – Bariatric Dietitian

Christina Archer, MS, RD - Clinical Dietitian

Christina Dominguez is a registered dietitian with a master’s degree in Nutritional Science from California State University, Chico and received board certification in integrative and functional nutrition. Her specialties are in plant-based nutrition, functional nutrition and gut-related disorders. She currently works at Sansum Clinic, providing individualized medical nutrition therapy for various health conditions as well as diet and lifestyle recommendations to lose weight or optimize health. She provides nutrition education for pre- and post-weight loss surgery patients and facilitates Sansum Clinic’s weight loss surgery support group.

In her spare time Christina enjoys baking, trail running and drinking a nice cup of coffee with her husband on the weekend.

Jessica Orozco - Bariatric Surgery Program Coordinator

Jessica Orozco, Bariatric Surgery Program Coordinaor

Jessica has worked with Dr. Zerey since 2008 assisting patients with their personalized bariatric surgery plan. She offers over 18 years of patient care experience. During your journey, she'll coordinate your plan of care, including scheduling appointments, navigating insurance coverage, answer any questions you may have, and be your source of comfort and encouragement as you work to achieve your weight loss goal. Jessica will guide you with confidence and care.

Unsure where to start? You can contact Jessica at 805-898-3472 to start your weight loss journey.

Rosana Herrera, LVN – Bariatric Nurse

Rosana Herrera, Bariatric Nurse

Rosana has been a licensed vocational nurse (LVN) since 2008. After working in various departments with Sansum Clinic, she found her true calling in 2014 when she joined Dr. Zerey and the Bariatric Surgery Team.

Rosana is an integral part of patient care leading up to and after surgery. She is here to monitor your progress and provide attentive and compassionate care. She will be your best point of contact for any pre-op and post-op questions.





Jacalyn Gross, LMFT

Jacalyn Gross, LMFT

Jacalyn was educated at the University of California, Santa Barbara, and Pacifica Graduate Institute in Counseling and Depth Psychology. She is a Licensed Marriage Family Therapist and on staff in the Sansum Psychiatry Department. She has been part of the Bariatric Surgery team since 2017. For over 20 years Jacalyn has focused her practice on mind body unity, using somatic, mindfulness, cognitive and behavioral therapeutic tools with patients. One’s health is not separate from their life story. The interview prior to Bariatric surgery is to encourage insight before transformation.