William E. Butler, MD

Vascular Neurosurgery Program

The Endovascular and Open Vascular Neurosurgery Program at Massachusetts General Hospital specializes in Neuroendovascular problems of the brain and spinal cord, including brain aneurysms, arteriovenous malformations (AVMs) and carotid disease.
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Contact us: 617-726-3303


Advanced Treatment for Complex Conditions

The Open Vascular Neurosurgery Program is one of the major programs in the United States to evaluate, diagnose and treat complex cerebrovascular disease, including, arteriovenous malformations (AVMs), cerebral aneurysms, carotid disease, Moya Moya, cavernous malformations and cerebrovascular disease of the spine. Our goal is provide each patient proper evaluation and treatment for their unique situation. Treatment options include:

  • Surgery. Operating through a small incision, our surgeons use microsurgical techniques to clip aneurysms and resect or remove AVMs and cavernous malformations.
  • Radiosurgery. Small AVMs inaccessible to surgery can be eradicated effectively and at low risk using radiation. Stereotactic techniques used in conjunction with angiography allow physicians to identify the exact location of the AVM. High energy focused radiation in the form of proton beam can be directed to the center of the AVM to minimize injury to surrounding brain tissue.
  • Endovascular Treatment. This technique uses the bloodstream through the femoral artery to access the brain to diagnose and treat brain aneurysms and AVM’s. In aneurysm management, the goal of treatment is to safely seal off the aneurysm to prevent rupture and to stop bleeding or rebleeding. Endovascular treatment for AVMs involves the injection of acrylic material through slender microcatheters which can be navigated through the cerebral arteries to the abnormal vessels in the AVM. Some lesions, can be treated to obliteration; in others the strategy is to eliminate particularly dangerous components of the AVM as well as decrease volume of the lesions.

State-of-the-Art Neurovascular Imaging

Our surgical team works with neuroradiologists and neurologists using state-of-the-art imaging techniques to diagnose your condition and develop effective treatment plans for even the most difficult cases. Mass General physicians help pinpoint the exact location of a vascular malformation, aneurysm or spinal cord vascular lesion using:

  • Ultra-precise injections of intracranial blood vessels via angiography
  • 3D angiography
  • Noninvasive computerized tomography angiography (CTA)

In the Neuro ICUs, we may also use other advanced diagnostics such as:

  • Ultrasound
  • CT scan (CT, portable CT and iCT)
  • Magnetic resonance imaging (iMRI & MRI)
  • Magnetic resonance angiography (iMRA & MRA)
  • Positron Emision Tomography (PET)
  • Venograms & Arteriograms

A Collaborative Approach to Care

Mass General takes a team approach to patient care. Your cerebrovascular clinician will coordinate all of your care with a multidisciplinary team of specialists. Together, the team:

  • Reviews patient health history and clinical presentation
  • Studies MRI, CTA and angiographic imaging data
  • Weighs risks and benefits of various approaches
  • Shares with the patient the appropriate course of treatment

This collaborative approach helps ensure that all patients receive the most appropriate care for their specific situation.

About this Program

Deep Experience and Global Reach

The Open Vascular Neurosurgery Program is part of the Mass General Vascular Center’s Brain Aneurysm and Arteriovenous Malformation Program, a collaboration of leading specialists in neurosurgery, neurology, interventional neuroradiology, nursing, physical therapy and social service. We provide treatment to patients throughout the United States and around the world.

The Brain Aneurysm and Arteriovenous Malformation Center is among the top ranked and highest-volume centers of its kind in the world. Every year we treat both ruptured and unruptured aneurysms. We also perform:

  • Carotid endarterectomies and stents
  • Craniotomies for AVMs
  • Craniotomies for cavernous malformations

Our neuroendovascular specialists consult with and treat patients from around the world.

We offer:

  • World-class expertise in the diagnosis, treatment management of neurovascular disease
  • Support groups for brain aneurysm and AVM patients and their family members
  • Education for patients, family members and the health care community
  • Day-to-day collaboration with and support for nurses, pharmacists, social workers, therapists and outside health care providers

Learn more about the Brain Aneurysm and Arteriovenous Malformation Program at the Vascular Center.

Clinical Trials, Research and Education

Our clinicians participate in major clinical studies evaluating new technologies and treatments in the management of cerebrovascular disease as well as studies to better understand the genetics and other risk factors in the development of brain aneurysms. These studies help us to bring our patients promising new treatments as quickly as possible.

Some of these studies include:

  • Clear III Clot Lysis: Evaluating Accelerated Resolution of Intraventricular Hemorrhage
    The Clear-III trial investigates the efficacy of using rt-PA (Alteplase) for clot resolution in patients with Intraventricular Hemorrhages. Patients are recruited from our critical care wards and either given doses of rt-PA or a placebo. The results are analyzed in collaboration with researchers at Johns Hopkins University and patient involvement is typically done at the end of one calendar year. Learn more
  • Minimally Invasive Surgery plus rt-PA for ICH Evaluation – ICES (endoscopy) arm
    The ICES arm of MISTIE explores the effectiveness of endoscopic surgery for the resolution of intracranial hemorrhages. The trial also explores other variables that might make such a surgery more effective. Patients are recruited from our critical care wards and assessed for their eligibility to advance to surgery. Learn more
  • Familial Intracranial Aneurysm Study (FIA)
    The FIA study explores the genetics of intracranial aneurysms. Patients and their families with strong medical histories of intracranial aneurysms are identified and recruited to this study. Once part of the study, various medical questions are asked and a blood sample is given to help determine the common genes that lead to familial development of intracranial aneurysms. Learn more
  • Study of Geometric Predictors of Cerebral Aneurysm Rupture (“CTA” study)
    In this longitudinal retrospective analysis, the size and shape of confirmed intracranial aneurysms are being studied as predictors of rupture. This is achieved by following patient imaging studies through time until the aneurysm ruptures or it is operated on. This study is currently being analyzed to definitively state the correlation.

Patients interested in participating in clinical trials can browse online for open trials.

Conditions & Diseases

  • Carotid Artery Disease

    Carotid artery disease, also called carotid artery stenosis, occurs when the carotid arteries, the main blood vessels that carry oxygenated blood to the brain, become narrowed.

  • Cerebral Aneurysm

    A cerebral aneurysm (also called an intracranial aneurysm or brain aneurysm) is a bulging, weakened area in the wall of an artery in the brain, resulting in an abnormal widening or ballooning. Because there is a weakened spot in the artery wall, there is a risk for rupture (bursting) of the aneurysm.

  • Stroke

    Stroke, also called brain attack, occurs when blood flow to the brain is disrupted.

Clinical Trials


Contact Us

Open Vascular Neurosurgery Program

Wang Ambulatory Care Center 745

15 Parkman Street Boston, MA 02114
  • Near Public Transit
  • Phone: 617-726-3303
  • Fax: 617-726-7501
Request an appointment

Contact us: 617-726-3303

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