At the HealthEast Kidney Stone Institute, we understand the impact of kidney stones. That's why our experienced team provides excellent care, whether you're experiencing a kidney stone for the first time or have dealt with them for years.

Andrew John Portis, MD
Chair, HealthEast Kidney Stone Institute

Andrew Portis, MD, is chair of HealthEast Kidney Stone Institute. He is dedicated to helping patients through the evaluation, treatment and prevention of kidney stones and stone disease. Dr. Portis believes deeply that education and prevention are essential parts of the treatment process. He works closely with patients to help them reduce the chances of developing future kidney stones.

Dr. Portis completed medical school and urology residency training in Edmonton, Alberta, Canada. He then completed a two-year fellowship in minimally invasive urology at the prestigious Barnes-Jewish Hospital, Washington University in St. Louis Medical School.

Since 2000, Dr. Portis has been providing innovative surgical solutions for upper urinary tract disease. He has also developed new strategies for clearing kidney stones, including ureteroscopic laser lithotripsy with active fragment clearance and tubeless percutaneous nephrolithotomy. Both procedures are less invasive than other treatment options and are highly effective.

Dr. Portis pays careful attention to his patients' outcomes and conducts research that has led to improvements in patient care. Actively involved in national and international research societies, he shares his findings with other urology specialists; Dr. Portis is passionate about helping others and has a special interest in treating Hmong Americans with kidney stones. His research has documented a high rate of uric acid stone disease in the Hmong community. He is actively working with the community to understand the causes and develop strategies to treat those with the uric acid stones.

Robert Glesne, MD

Robert Glesne, MD, completed his urology training at the University of Iowa. He practiced general urology primarily in Alexandria, Minnesota. He has now transitioned his practice to focus on kidney stone disease and joined HealthEast Kidney Stone Institute in September 2010.

Dr. Glesne brings a wealth of clinical experience to Kidney Stone Institute. His patient-centered care philosophy and drive for optimal treatment outcomes makes him a valued addition to Kidney Stone Institute.

Carl Bretzke, MD
Interventional Radiologist

Carl Bretzke, MD, is a board-certified radiologist. He has been a member of St. Joseph's Hospital medical staff since 1987 and was chairman of the hospital's radiology department from 1995 to 2005.

Born and raised in Hutchinson, Minnesota, Dr. Bretzke earned a bachelor's degree from the University of Colorado, Boulder and then completed medical school and residency training at the University of Minnesota. Dr. Bretzke trained in interventional radiology with Kurt Amplatz, MD, a pioneer in interventional radiology and endourology.

Dr. Bretzke plays a dual role within HealthEast Kidney Stone Institute. His extensive experience in body imaging is a valued resource for challenging diagnostic questions. As well, Dr. Bretzke is an important partner in Kidney Stone Institute's team-oriented approach to treating complex stone disease using percutaneous nephrolithotomy (PCNL). Dr Bretzke was pivotal in the evolution of the advanced techniques developed at Kidney Stone Institute which have profoundly increased effectiveness and decreased discomfort for this challenging patient population.

Justine Politz, RN, WHCNP-BC, RNC-REINP, C-MC

Justine joined HealthEast Kidney Stone Institute as a nurse practitioner in 2009, bringing more than 30 years of nursing and nurse practitioner experience in both clinic and hospital settings. Being triple board certified and working in many different medical organizations has added to her knowledge and enhances our patients' overall experiences and care.

Justine obtained her nursing degree from Austin Community College and furthered her training at the University of Minnesota. Her board certifications include women's health, menopause and reproductive endocrinology/infertility.

Justine is passionate about providing compassionate, individualized patient care and education. She is grateful for the privilege to care for kidney stone patients and their families.

Karrie Masog, RN

Karrie joined HealthEast Kidney Stone Institute as clinical manager in 2011, bringing over ten years of nursing experience caring for patients with an array of complex medical conditions, including vascular disease, chronic pain, and cancer.

Karrie earned a baccalaureate of science degree in community health and patient education from Minnesota State University - Mankato and completed her clinical rotations at the Mayo Clinic while earning her associate of science degree in nursing.

Karrie is excited to bring her knowledge and enthusiasm for patient education to HealthEast Kidney Stone Institute, where she has the opportunity to support a care team that encourages the patients and their families to be active contributors in their own care and treatment plan.

She recognizes how difficult it can be for patients to understand their disease and treatment options, but believes education combined with compassion is the key to empowering patients to actively participate and drive better outcomes.

Mary Hitzeman RD, LD

Registered Dietitian Mary Hitzeman has more than eight years of experience in the health and wellness industry focusing on individual and group counseling/coaching and program development.

Mary obtained her bachelor's degree in nutrition and dietetics from Purdue University and completed her dietetic internship at University of Iowa Hospitals and Clinics. She also holds a certificate in adult weight management through the American Dietetic Association (ADA).

Mary is excited to work within HealthEast Kidney Stone Institute. She has a passion for helping patients initiate small lifestyle changes so they can live healthier, happier, more active lives. She understands it's challenging for patients to make changes and strives to provide up-to-date resources to help. Most of all, she offers support and encouragement along the way.