Trauma & Neurosurgery

Dr. Spears is the current Head of the Division of Neurosurgery at St. Michael’s Hospital in Toronto. He entered the Neurosurgery Training Program at the University of Toronto in 1998. He became a Fellow of the Royal College of Physicians and Surgeons of Canada in 2004. Following residency, Dr. Spears completed a two-year fellowship in Endovascular Neurosurgery at the University of Toronto. During his training, Julian undertook graduate studies in Clinical Epidemiology and successfully obtained his Masters of Science degree from the Harvard School of Public Health in 2006. He became a Fellow of the American College of Surgeons in 2008.

Dr. Spears holds a co-appointment in the Division of Neurosurgery and Department of Medical Imaging at St. Michael’s Hospital as Assistant Professor. He is also Co-Director of the Neurovascular Program at St. Michael’s Hospital, an Adjunct Scientist in the Keenan Research Centre of the Li Ka Shing Knowledge Institute, and Associate Program Director of the Division of Neurosurgery Training Program at the University of Toronto. Dr. Spears’ research interests are primarily in cerebrovascular clinical trials.

Clinical Focus: Brain Aneurysms, Arteriovenous Malformations, Endovascular Neurosurgery, Carotid Endarterectomy and Stenting Cerebrovascular Disease, Brain and Spinal Tumours

Academic Focus: Cerebrovascular Disease, Cerebral Aneurysms, Arteriovenous Malformations

Department: Surgery

Division: NeuroSurgery

Clinics: Neurovascular Clinic

Languages: English

Contact Information:
Clinic/Referrals:
Phone: 416-864-5131
Fax: 416-864-5176
Location: St. Michael’s Hospital

Director of Endovascular Research and Innovation
Schroeder Chair in Advanced Neurovascular Interventions
Lead Scientist/ RADIS lab/ Li Ka Shing Knowledge Institute
Division of Neurosurgery – Department of Surgery/ St Michael’s Hospital – Unity Health Toronto
St. Michael Hospital
Professor of Surgery and Medical Imaging/ University of Toronto

Dr. Vitor Mendes Pereira is a neurosurgeon specialized in endovascular procedures to treat neurovascular diseases of the brain and spine, including Stroke, Brain Aneurysms, Arteriovenous Malformations, Vascular Causes of Pulsatile Tinnitus, Intracranial Hypertension, Dural Fistulas, Carotid and Intracranial Stenosis (Atherosclerotic Diseases) and percutaneous pain procedures in adult and pediatric patients.

He completed a neurosurgery residency at the State University of Sao Paulo, Brazil, and his clinical fellowship and master's degree in France (CHU Bicetre and Rothschild Foundation). From 2008-2014, Dr. Pereira worked as the Head of the Interventional Neuroradiology division and Privat-Docent at the University Hospital of Geneva, Switzerland. In 2014, he joined the University of Toronto as an Associate Professor and worked at the UHN/Toronto Western Hospital and Hospital for Sick Children. In April/2021, Dr. Pereira joins the Division of Neurosurgery, Department of Surgery at St Michael’s Hospital as the Director of Endovascular Research and Innovation. He is currently a Professor at UofT, and he holds the Schroeder Chair in Advanced Neurovascular Interventions.

Dr. Pereira is a pioneer in stent retrievers use in acute stroke and perhaps holds the most extensive experience with flow diverters interventions worldwide. He is interested in diagnosing and treating intracranial venous diseases, including idiopathic intracranial hypertension and pulsatile tinnitus. He is involved in many research and innovative translational projects, and, most recently, he performed the world’s first robotic neurovascular intervention. He plans to advance the possibility of remote endovascular treatments in the future.

He is the lead scientist of the RADIS lab, which focuses on studying innovative technologies and their potential applications to vascular neurosurgery, including computational fluid dynamics, dynamic diagnostic imaging, genetics, and molecular biology. Artificial Intelligence and Robotics are two of the most profound technological advances of the last decade. This lab focuses on leveraging these technologies to improve the outcomes of patients with neurovascular diseases.

Dr. Pereira is engaged in education in the field of endovascular neurosurgery. He organizes advanced training in new techniques and participates in courses and workshops worldwide, teaching cerebral and spinal vascular anatomy, imaging, and advanced endovascular treatments. He has contributed over 270 publications to this evolving and dynamic field.

Department: Surgery
Division: Surgery
Clinics: Neurovascular Clinic
Languages: English, French, Portuguese, Spanish
Contact Information:
Clinic/Referrals:
Phone: 416-360-4000 ext. 77113
Fax: 416-864-5176
Location: St. Michael’s Hospital

Dr. Marotta has a long history with St. Michael’s Hospital. He was born here. He also trained here. St. Michael’s Hospital is also where his mother and father met — she was a nurse and he became chief of Medicine. Today, Dr. Tom Marotta runs a weekly neurovascular clinic in the Marotta Clinic, named in honour of his father’s contributions in neurology and medicine.

Dr. Marotta is a minimally invasive neurointerventionalist. He treats patients with neurovascular conditions such as acute strokes and ruptured brain aneurysms. “We see patients with complex neurovascular conditions that require input from many areas including neurosurgery, neurology, neuroradiology and interventional neuroradiology.”

It is this collaborative team that makes St. Michael’s Hospital a great place to work. “Each of us has a different area of interest and expertise that we combine for the benefit of our patients,” he says.

Dr. Marotta trained as an intern, a neurosurgical resident and radiology resident at St. Michael’s Hospital before pursuing further training and practice in Canada and the United States. After establishing a neurointerventional service at Vancouver General Hospital, he returned to St. Michael’s in 2001 to support a similar program here with Dr. Walter Montanera. Today this program sees patients from across Toronto, throughout Ontario and beyond.

Dr. Marotta also participates in clinical studies to better understand neurovascular conditions and to develop new ways to treat them. Specifically, he has a particular focus on developing new devices to treat patients with brain aneurysms in a less invasive way. For example, he has his own patented invention to treat brain aneurysms that has been used to treat patients here in Canada and abroad.

“St. Michael’s Hospital is a supportive environment to work in, to train others, and to conduct innovative research,” he says. “Everything we do is with our patients
in mind and it is an honour to work with such an outstanding team.”

Clinical Interests and Areas of Expertise: Complex aneurysm repair, Flow diversion, Acute carotid disease.
Academic Interests (Research, Teaching/Education, Quality Improvement etc.): Device development/testing, Teaching INR Fellows
Personal Statement: St. Michael’s is my home away from home.
Department: Radiology
Division: Interventional Neuroradiology
Clinics: Neurovascular Clinic
Contact Information:

Clinic/Referrals:
Phone: 416-864-5131
Fax: 416-864-5176
Location: St. Michael’s Hospital

Dr. Jose Danilo Diestro is a vascular neurologist subspecialty training in interventional neuroradiology. His expertise lies in the medical and endovascular management of various vascular conditions affecting the brain and spine, such as stroke, carotid artery stenosis, aneurysms, fistulae, and arteriovenous malformations.

Dr. Diestro completed his residency training in Adult Neurology and pursued a fellowship in Stroke at the University of the Philippines-Philippine General Hospital. He further honed his skills through fellowship training in Interventional Neuroradiology at esteemed Canadian institutions including the University of Toronto (St. Michael’s Hospital) and the Université de Montréal (Centre Hospitalier de l'Université de Montréal). At St. Mike’s, he received training under the supervision of his program director, Dr. Thomas Marotta.

He has made contributions to the field of vascular and interventional neurology, with his work being published and presented at various conferences in Canada and the Philippines. Dr. Diestro's research interests primarily revolve around acute stroke neuroimaging, long-term neurological outcomes of subarachnoid hemorrhage, and the development of innovative devices for aneurysm treatment. His dedication to methodologically sound research has led him to pursue additional graduate studies with a focus on epidemiology.

Dr. Diestro firmly believes that neurointervention is a collaborative discipline involving neurologists, neurosurgeons, and radiologists, working together to provide exceptional patient care and ensure a positive health-care experience.

Clinical Focus: Acute stroke interventions, Aneurysms, Carotid disease
Academic Focus: Stroke, Subarachnoid hemorrhage, Devices for aneurysm treatment

Department: Medicine
Division: Neurology
Clinics: Neurovascular Clinic
Languages: English, Filipino

Contact information:
Clinic/Referrals:
Phone: 416-864-5365
Fax: 416-864-5176

Twitter: @DanniDiestro
Location: St. Michael’s Hospital

Nicole Cancelliere is the Neurovascular Research Program Manager at St. Michael’s Hospital and also works as a medial radiation technologist specialized in supporting neurointerventional & robotic-assisted procedures. She completed her collaborative undergraduate degree and X-ray technology diploma at Queen’s University and the Eastern Ontario School of X-ray Technology in 2013, and then went on to complete her Master’s degree in Neuroscience.

As a clinical research technologist, Nicole works with both the clinical and research teams, supporting innovative patient care in the field of brain hemodynamics and neurovascular disease. As co-lead of the RADIS lab, the collaborative research team uses advanced technologies, including Robotics, AI, Dynamic Flow, Imaging and Simulation, to develop
new approaches to improve diagnosis and treatment of neurovascular diseases. Nicole is certified as a specialized neurovascular robotic technologist and was a part of Dr. Pereira’s clinical team which performed the world’s first robotic neurovascular intervention in the world on November 1, 2019.

She is also very passionate about advancing minimally invasive neurosurgery and radiography training & education and has helped run several ischemic and hemorrhagic workshops globally using advanced simulators and 3D-printed vascular models. She is also actively involved with the Medical Radiation Sciences program at the University of Toronto and Michener Institute where she is involved in course development and interventional
radiology education. Nicole sits on the Canadian Association of Medical Radiation Technologists (CAMRT) Research Grant Committee that works to advance the field by providing financial support for worthy humanitarian, educational and scientific contributions through research by the profession. Nicole is committed to promoting a model of research integration with clinical specialty among future fellow technologists.

Eileen Liu is a certified Project Manager who is currently working as a Research Coordinator III for the Neurovascular Program at St. Michael’s Hospital. She obtained her Bachelor of Science (Honours) degree at Queen’s University and obtained her Master’s degree in Medical Science at the University of Toronto. Eileen is involved in the management and coordination of various clinical trials and projects involving neurovascular diseases including stroke, carotid artery stenosis, brain aneurysms, idiopathic intracranial hypertension, and more.