The Interventional Neuroradiology or Endovascular Surgical Neuroradiology (ESN) Fellowship is a clinical program offered under the aegis of the Mallinckrodt Institute of Radiology and the Department of Neurological Surgery at Washington University School of Medicine.

Established in 1994, the ENS Fellowship Program was the first ACGME-accredited INR fellowship in the nation, and it is currently one of only seven such programs. The program holds a dual accreditation through the Society of Neurological Surgeons’ Committee on Advanced Subspecialty Training, which is highly endorsed by the Society of Neurointerventional Surgery, AANS/CNS Joint Section on Cerebrovascular Surgery, and the Society of Vascular and Interventional Neurology

Program goals and objectives

There are three primary goals of the ESN Fellowship program:

  1. to provide clinical training encompassing essentially all areas of endovascular surgical neuroradiology
  2. to provide an understanding of disease symptomatology and pathophysiology relating to those disease states that are amenable to treatment with endovascular surgical neuroradiology
  3. to provide an opportunity for a meaningful and productive experience in research


Applicants from a neurosurgical background must complete a prerequisite year of diagnostic catheter angiography and imaging training. This can be acquired during residency. One prerequisite for radiology trainees is a year of diagnostic neuroradiology training. If possible, we prefer that this training be done at our institution.

Applicants from Radiology Residency

  1. Diagnostic Neuroradiology Fellowship
  2. Completion of 100 or more diagnostic cerebral angiograms
  3. Months of rotations on Neurosurgery, Neurology and Neurocritical Care

NOTE: We offer Diagnostic Neuroradiology and ESN as a combined two-year fellowship. Prerequisite rotations must be completed prior to the diagnostic neuroradiology year (excluding the diagnostic cerebral angiography requirement).

Applicants from neurosurgery residency

  1. Completion of a 7-year neurosurgery residency
  2. Completion of 100 diagnostic cerebral angiograms

Applicants from neurology residency

  1. Completion of a one-year stroke/vascular neurology fellowship or a two-year neurocritical care fellowship
  2. Completion of 100 diagnostic cerebral angiograms

Clinical Service

The Interventional Neuroradiology Service is responsible for all endovascular neurosurgical procedures at Barnes-Jewish and St. Louis Children’s hospitals. There are four full-time neuro-endovascular faculty:

Brendan Eby, MD
Arindam Chatterjee, MD
Christopher J. Moran, MD
Joshua W. Osbun, MD
Ananth K. Vellimana, MD

The ESN fellowship program is directed by Dr. Chatterjee.

Program Highlights


  • Hands-on training from multidisciplinary faculty mentors with deep experience training fellows
  • 1000+ diagnostic cerebral and spinal angiograms and 500+ neurointerventional procedures per year; a diverse collection of aneurysms, arteriovenous fistulae and arteriovenous malformations, thrombectomy for stroke, carotid artery disease, intraoperative angiography and transradial access
  • Comprehensive stroke center with highest volume of stroke admissions in the region and the largest dedicated neurological ICU in the nation


  • Multiple ongoing trials for novel endovascular devices
  • Numerous multicenter research projects spanning a wide range of diseases
  • INR faculty who are recognized leaders in research


  • Weekly joint neuroradiology, neurosurgery and neurology cerebrovascular teaching conference
  •  Weekly didactic teaching sessions
  • Graduates become leaders in neurointervention (presidents of major societies, developers of major endovascular technologies, leaders of field-changing studies, leaders of INR service lines across the nation)

Contact Information

To obtain more information or to request an application, please email one of the following: