Our Staff

Our Staff*


Position: Physician Practice Clinic Coordinator

Email: kmartin@nobilishealth.com

Phone: 713-993-7124

Kris is the Clinic Coordinator and has been with Dr. Marvin since 2009. She works closely with our patients after their initial consult with Dr. Marvin to get all their necessary medical testing scheduled and completed before surgery. She is also the point of contact for patients after surgery with their questions and concerns. Kris has a great compassion for each patient to ensure they feel comfortable and informed through their entire process.


Position: Physician Financial Business Coordinator

Email: denise@doctormarvin.com

Phone: 713-993-7124

Denise joined Houston Surgical Specialists in May of 2014. She has a vast amount of experience with patient financial counseling, medical billing and coding. Patient accounts and medical information are handled with proficiency and maintained accurately. As our Physician Financial Business Coordinator, Denise audits, analyzes and confirms all patients’ data submitted for authorization approval to health insurance companies. She ensures all criteria for bariatric surgery requirements for in-network and out-of-network insurance companies are accurate and up to date. Denise believes in core values of respect, compassion and excellence in all roles.


Position: Physician Patient Services Coordinator

Email: mrambin@nobilishealth.com

Phone: 713-993-7124

Mary joined Houston Surgical Specialists in early 2017. She has many years of experience with patient services and business processes in specially medicine. Mary is appreciated by the patients and staff with her acuity in operational efficiency, organization and compliance. With a light up smile, she insists that no problem is too big or small and she will find the solution. As one who delights in the joy of others, she encourages patients to share their journey of success to be the inspiration of others.


Position: Physician Practice Development Coordinator

Email: sheila@doctormarvin.com

Phone: 713-341-6206

Joining the practice in early 2017, Sheila brings a dedication to growing the practice by sharing our success with health care professionals by implementing the clinic’s mission and strategic vision. As a physician liaison, event project manager and patient service manager, her experience creates an ideal model for community outreach. After struggling with being overweight many years, Sheila is now a triathlete who swims, cycles and runs. She understands the difficulty in starting a weight loss plan and the importance of maintaining a healthy lifestyle. By creating a directory of trainers, coaches and nutrition specialist, Sheila is also a fitness advocate for our patients. Sheila earned her B.A. in Communications from the University of Texas.

Triathlete Fundraiser for Discover Fitness Foundation (Reason2Race)

Our mission is to improve the quality of lives for children with special needs, children fighting obesity, and talented athletes by inspiring them to participate in recreational and competitive level of gymnastics. We promise to nurture potential, promote dignity, and support bold steps by all.

Board of Directors, Membership for Houston Racing Triathlon Club

Houston Racing Triathlon Club (HRTC) was created in an effort to bring together Houston’s triathletes to train and share their common interests with one another; and to increase awareness of and participation in the sport.


Position: Physician Practice Medical Billing and Coding

Email: sylvia@doctormarvin.com

Houston Surgical Specialist has entrusted Sylvia with medical billing and coding since 2011. After a few years’ sabbatical, she returned in early 2017. With so many changes in healthcare, her expertise is invaluable to ensure proper guidelines are met and patient billing is exact. Sylvia works closely with the Financial Business Coordinator to ensure accurate and timely processing. Her soft-spoken demeanor and genuine smile is also an invaluable trait. Please direct all billing questions to Denise listed above, yet should you need to contact Sylvia you may do so at sylvia@doctormarvin.com.



Position: Surgical Assistant

Email: theresa@doctormarvin.com

Phone: 713-993-7124

Theresa assists Doctor Marvin in the operating room for all bariatric surgeries. Since most weight loss operations are done using the laparoscopic technique, an experienced assistant who can handle the scope and other instruments is vital. Theresa has assisted Dr. Marvin on hundreds of bariatric cases.


Position: Phlebotomist

As an integral part of our team, Violet performs all the collection requirements for laboratory testing. We are pleased her employer, Clearview Diagnostics, allows us the pleasure of her enduring smile. Our patients have confidence in Violet’s unique style of empathy with exceptional precision.

Renell Cronk, RD

Position: Registered Dietician with PsyMed, Inc.,
Partner for Psych and Nutrition consultations

Phone: 214-348-5557

Renell Cronk is a Registered Dietitian and Nutritionist who graduated from the University of Idaho with a Bachelor of Science in Food Nutrition/Dietetics with a Minor in Psychology. Over the years, Renell has acquired many skills in the area of food, nutrition, supplements and healthy lifestyles. She has experience working in various fields of nutrition but her primary passion and specialty is weight management. Nothing gives Renell a greater feeling of accomplishment and joy than helping individuals achieve their health and nutrition goals!

* Results will vary by person and are based upon the patient, the surgery type and the compliance with the aftercare program. As with any medical procedure or surgery, there are specific risks and possible complications. The testimonials, statements, and opinions presented on our website are applicable to the individuals depicted. Results may not be representative of the experience of others. Testimonials are voluntarily provided and are not paid, nor were they provided with free products, services, or any benefits in exchange for said statements. The testimonials are representative of patient experience but the exact number of pounds lost and experience will be unique and individual to each patient.

Make an appointment with Dr. Marvin for diagnosis and treatment.