Illustration of spinal AVM classification evolution.

Unraveling Spinal AVMs: A Journey Through Evolving Classification Systems

Samir D’Costa in Health & Wellness July 2025 • 4 min read.

"Explore how advances in imaging, microsurgery, and endovascular techniques have reshaped the classification of spinal arteriovenous malformations (AVMs) over time."

Spinal arteriovenous malformations (AVMs) present a unique challenge due to the myriad of classification systems proposed over the years. This abundance of systems can lead to confusion, especially when textbooks and research papers seem to contradict each other.

To clarify this complex landscape, we'll explore the evolution of spinal AVM classification, tracing its development through key research and technological advancements. By understanding the historical context, we can better navigate the current classification systems and their practical applications.

This article draws upon English language literature from 1967 to 2015, focusing on landmark papers and updates that have significantly shaped how we understand and categorize these intricate vascular malformations.

From Angiograms to Advanced Imaging: Milestones in AVM Classification

Illustration of spinal AVM classification evolution.

The classification of spinal AVMs has evolved through distinct generations, each marked by advancements in diagnostic and interventional techniques. Here's a look at the key milestones:

The First Generation: Initial classifications emerged with the advent of spinal angiography in 1971. Di Chiro's work categorized AVMs into single coiled vessel, glomus, and juvenile types. However, the limited resolution of early imaging made detailed assessments challenging.

1971: First description of spinal dural arteriovenous fistulas (AVFs) and intradural AVMs diagnosed by spinal angiography.
1986: Second-generation classification based on case reports of intradural perimedullary AVFs treated by microsurgery.
1993: Third-generation classification based on case series of intradural perimedullary AVFs treated by endovascular interventions.
2002: Fourth-generation classification based on case series of spinal AVMs treated by microsurgery and endovascular interventions.
2009 & 2011: Fifth-generation classification based on case series of extradural AVFs treated by microsurgery and endovascular interventions.

Later Generations: Subsequent classifications refined the understanding of AVM types, location, and feeding vessels. The introduction of microsurgery and endovascular techniques allowed for more detailed anatomical studies, leading to more precise classifications. Spetzler's 2002 classification attempted to categorize AVMs based on their location and angioarchitecture, but this system was not widely adopted due to its complexity.

Navigating the Future of AVM Classification

The classification of spinal AVMs has been significantly influenced by the evolution of diagnostic imaging, microsurgery, and endovascular treatment. These advancements have allowed for more detailed characterization and understanding of AVM anatomy and hemodynamics.

While various classification systems have been proposed, the third generation, combined with the classification of extradural AVFs, offers a practical framework. Integrating historical context helps to understand the nuances and limitations of each system.

Moving forward, the integration of high-resolution imaging with pathological findings will be crucial for refining AVM classification and treatment strategies. This multidisciplinary approach promises to improve diagnostic accuracy and optimize patient outcomes.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.7887/jcns.26.326, Alternate LINK

Title: Historical Changes In The Classification Systems Of Spinal Arteriovenous Malformations

Subject: Neurology (clinical)

Journal: Japanese Journal of Neurosurgery

Publisher: The Japanese Congress of Neurological Surgeons

Authors: Keisuke Takai

Published: 2017-01-01

Everything You Need To Know

How were spinal arteriovenous malformations (AVMs) initially classified, and what were the limitations of this early classification?

Spinal arteriovenous malformations (AVMs) were initially classified using spinal angiography, which led to the categorization by Di Chiro in 1971 into single coiled vessel, glomus, and juvenile types. However, these early classifications were limited by the resolution of the imaging technology available at the time, making detailed assessments challenging. This initial classification was based on the appearance of the AVMs on angiograms, without the benefit of detailed anatomical or hemodynamic information that later imaging modalities would provide.

How did later generations of spinal AVM classifications build upon the initial classifications, and what specific advancements contributed to these refinements?

Later generations of spinal AVM classifications, such as Spetzler's 2002 classification, built upon the initial classifications by incorporating more detailed anatomical studies made possible by microsurgery and endovascular techniques. Spetzler's classification, for example, attempted to categorize AVMs based on their location and angioarchitecture. These classifications aimed to provide a more precise understanding of AVM types, location, and feeding vessels, which could then inform treatment decisions. Although not widely adopted due to its complexity, Spetzler's system reflects the ongoing effort to refine AVM classification in light of evolving surgical and interventional approaches.

In what ways has the evolution of diagnostic imaging, microsurgery, and endovascular treatment impacted the classification of spinal AVMs?

The evolution of diagnostic imaging, microsurgery, and endovascular treatment has significantly impacted the classification of spinal AVMs. Advances in imaging, such as higher resolution angiography and MRI, have allowed for more detailed characterization of AVM anatomy and hemodynamics. Microsurgery and endovascular techniques have provided opportunities to study AVMs directly and to develop new classification systems based on surgical and interventional findings. These advancements have led to more precise and clinically relevant classification systems.

Can you explain the different generations of spinal arteriovenous malformation classifications?

The classification of spinal AVMs has evolved through distinct generations, with the first generation emerging around 1971 with the advent of spinal angiography, categorizing AVMs into types like single coiled vessel, glomus, and juvenile. Subsequent generations refined the understanding of AVM types, location, and feeding vessels, incorporating advancements such as microsurgery and endovascular techniques. For example, classifications emerged based on case reports and series involving intradural perimedullary AVFs treated by microsurgery and endovascular interventions in later years.

What does the evolution in classification systems after the first generation tell us about our evolving understanding of spinal AVMs and the role of treatment modalities?

The classification systems after the first generation, such as the classifications based on case reports of intradural perimedullary AVFs treated by microsurgery (1986) and endovascular interventions (1993), and the classification based on case series of spinal AVMs treated by both methods (2002), represent significant advancements. These classifications reflected a shift towards incorporating treatment modalities into the classification process, allowing for a more comprehensive understanding of AVMs in the context of their clinical management. Additionally, the fifth-generation classification in 2009 and 2011, focusing on extradural AVFs, further expanded the scope of spinal AVM classification.