Meet the Team

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Dr. Sandra de Montbrun

Dr. Sandra de Montbrun is a Royal College certified colorectal surgeon at Oakville Trafalgar Memorial Hospital, dedicated to providing expert, compassionate care for patients with colorectal conditions.

After completing her medical degree at the University of Toronto and surgical training at Dalhousie University, Dr. de Montbrun returned to Toronto for specialized fellowship training in colorectal surgery, focusing on colorectal cancer and inflammatory bowel disease. She is also certified in da Vinci robotic surgery, offering patients minimally invasive options with faster recovery. She also holds a Master’s in Education and a PhD, reflecting her passion for surgical education and innovation.

Before joining Oakville Trafalgar, Dr. de Montbrun built a busy colorectal surgery practice at St. Michael’s Hospital in Toronto, where she cared for patients with complex colorectal cancers and IBD and contributed to international advancements in surgical training.

Now based in Oakville, Dr. de Montbrun brings her expertise and warmth to the community—offering comprehensive care for colon and rectal cancer, Crohn’s disease, ulcerative colitis, diverticular disease, and perianal conditions such as hemorrhoids and fissures. Known for her thoughtful approach and commitment to patient well-being, she strives to make every patient feel informed, supported, and confident in their care.

Nataliia Barna

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Office Administrator

Nataliia is the heart of our practice. As our office administrator, she brings warmth, care, and exceptional organization to everything she does. She ensures the office runs seamlessly while creating a welcoming, supportive environment for every patient. Her kindness and professionalism make her an invaluable part of our surgical family.

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Yamilee Julien

Colorectal Cancer Nurse Navigator

Yamilee is the guiding hand of our Colorectal Diagnostic Assessment Program (DAP). As our nurse navigator, she supports patients through every step of their diagnostic journey with compassion, clarity, and care. From coordinating tests and appointments to answering questions and offering reassurance, Yamilee ensures patients feel informed, supported, and never alone. Her dedication helps make a complex process feel seamless and personal.

Margarita Machura

Stoma Education & Support

Margarita Machura, BScN, RN (Prescriber) brings years of experience caring for colorectal surgical patients and a compassionate, patient-centred approach to nursing care. Working collaboratively with Dr. de Montbrun and the surgical team, she provides personalized education and support to help patients develop the knowledge, confidence, and practical skills to successfully manage their stoma, optimize skin health, and transition confidently back to everyday life.

For more information or to request an appointment, please contact the office.