Dr Pascal J. Mosimann

Dr Pascal J. MosimannMD, PD

Neurointerventionalist

Associate Professor of Neuroradiology & Neurosurgery, University of Toronto

Senior Staff & Fellowship Program Supervisor (Director), Interventional & Diagnostic Neuroradiology, Toronto Western & Toronto General Hospitals

I treat complex vascular diseases of the brain and spine through the blood vessels, and I invent the devices to do it better, safer or faster.

More than 4,000 interventions as first operator. Inventor of neurovascular devices, and mentor to fellows from more than 30 countries, many now leading their own programs.

Training and practice

from the Swiss Alps to the shores of Lake Ontario (still searching for the mountains)

Clinical focus

interventional neuroradiology (endovascular neurosurgery)
  • Aneurysms & flow diversion
  • Brain AVM curative embolization
  • Chronic subdural (MMA embolization)
  • CSF-venous fistula
  • Dural & carotid-cavernous fistulas
  • Head & neck / tumour embolization
  • Pediatric neurointervention
  • Pulsatile tinnitus & venous disease
  • Stroke thrombectomy
  • Vascular-malformation sclerotherapy

Leadership. Former Head of the Division of Neuroradiology at University Health Network, Toronto General and Western (2022–25), and, since 2024, formally Fellowship Program Supervisor (Director) of the interventional neuroradiology program at the University of Toronto. Course Director of PIKES, the pan-Canadian Karel ter Brugge educational symposium in interventional neuroradiology, neurology and neurosurgery. Former stroke-centre certification auditor, national board examiner and Editorial Board member (Journal of Neuroradiology). Proctor and consultant for multiple medtech companies.

Innovation and impact

  • Pressure cooker technique
    Co-developed with my mentor René Chapot, used worldwide to cure selected AVMs and dural fistulas through better control of liquid embolic agents.
  • Robotic endovascular navigation
    I co-invented MAGFLOW, a flow-driven magnetic microcatheter for remote superselective navigation and embolization, published in Science Robotics (2025) and Nature Communications (2020).
  • Device patents
    Two patent families: a photoactivated liquid embolic for aneurysms, and an enhanced-torque steerable guidewire.
Cumulative peer-reviewed output, reaching 128 publications
20112026

In conversation

Interventional neuroradiology, the work and how to build a career in it. Podcast Radiologists, episode 27 (University Medical Imaging Toronto).

Beyond the clinic

I have been a patient too. That vulnerability, and the worry about whether you will wake up the same, is an anxiety your family carries with you. Surrendering and trusting someone you barely know in that moment takes real courage. Each patient I counsel or operate on, whatever their story, is approached with the same care and focus as a member of my own family. Brain and spine diseases can be frightening, and when I study your chart and images, I do it with a deep sense of responsibility and compassion. That is the standard I hold myself to, and the one I try to pass on.

Medicine does not always go the way we hope. When it does not, I do not step back. I stay with the patient and the family, and I carry those moments with me.

My former Paris co-fellow Dr Eugen Enesi built interventional neuroradiology in Albania from almost nothing, and I was glad to help where I could. Teaching matters to me for the same reason the bedside does: putting the small, hard-to-teach details into words, so trainees understand and integrate them faster, growing into independent thinkers ready to face the unexpected with humility, judgement and creativity. Few things make me prouder than watching a hesitant fellow become a sure-handed operator, and a colleague I learn from in turn.

Some of the best in the field trained me, and gave me the room to push myself as far as I could. What I want now is simple: to keep building new tools with the engineers who bring them to patients, to help others treat neurovascular diseases well, and to give back to those who need it most.

Ways to collaborate

Clinical program leadershipBuilding and directing neurovascular services and interventional-neuroradiology fellowship training.
Device development and evaluationFrom concept and bench models through first-in-human and clinical assessment.
Investigator-initiated trialsRegistries and prospective studies run as principal investigator.
Proctoring and educationCase proctoring, course direction, and hands-on training.

If you are a physician with a complex case, a trainee, or a builder working on the next tool, I would like to hear from you. Reach me at pascal.mosimann@uhn.ca or on LinkedIn.