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Updated: Jun 12, 2026
Comprehensive Endovascular and Open Surgical Management of Cerebral Arteriovenous Malformations
Published on: October 20, 2017
Repeat γ knife surgery for incompletely obliterated cerebral arteriovenous malformations
Chun-Po Yen1, Surbhi Jain, Iftikhar-ul Haq
1Lars Leksell Center for Gamma Surgery, Department of Neurological Surgery, University of Virginia Health Sciences System, Charlottesville, Virginia 22908, USA.
Objective:
The causes of failure after an initial Gamma procedure were studied, along with imaging and clinical outcomes, in a series of 140 patients with cerebral arteriovenous malformations (AVMs) treated with repeat Gamma Knife surgery (GKS).
Methods:
Causes of initial treatment failure included inaccurate nidus definition in 14 patients, failure to fill part of the nidus as a result of hemodynamic factors in 16, recanalization of embolized AVM compartments in 6, and suboptimal dose (<20 Gy) in 23. Nineteen patients had repeat GKS for subtotal obliteration of AVMs. In 62 patients, the AVM failed to obliterate despite correct target definition and adequate dose. At the time of retreatment, the nidus volume ranged from 0.1 to 6.9 cm3 (mean, 1.4 cm3), and the mean prescription dose was 20.3 Gy.
Results:
Repeat GKS yielded a total angiographic obliteration in 77 patients (55%) and subtotal obliteration in 9 (6.4%). In 38 patients (27.1%), the AVMs remained patent, and in 16 patients (11.4%), no flow voids were observed on magnetic resonance imaging. Clinically, 126 patients improved or remained stable, and 14 experienced deterioration (8 resulting from a rebleed, 2 caused by persistent arteriovenous shunting, and 4 related to radiation-induced changes).
Conclusion:
By using repeat GKS, we achieved a 55% angiographic cure rate. Although radiation-induced changes as visualized on magnetic resonance imaging occurred in 48 patients (39%), only 4 patients (3.6%) developed permanent neurological deficits. These findings may be useful in deciding the management of AVMs in whom total obliteration after initial GKS was not achieved.
Insights
Repeat Gamma Knife surgery (GKS) offers a 55% cure rate for cerebral arteriovenous malformations (AVMs) that didn't fully obliterate after initial treatment. While some radiation changes occur, permanent deficits are rare, aiding management decisions.
Area of Science:
- Neurosurgery
- Radiosurgery
- Neurology
Background:
- Cerebral arteriovenous malformations (AVMs) can fail to obliterate after initial Gamma Knife surgery (GKS).
- Understanding failure modes is crucial for optimizing retreatment strategies.
Purpose of the Study:
- To investigate the causes of failure after initial GKS for AVMs.
- To evaluate imaging and clinical outcomes of repeat GKS in 140 patients.
Main Methods:
- Retrospective analysis of 140 patients with AVMs undergoing repeat GKS.
- Analysis of initial treatment failures including nidus definition, hemodynamics, recanalization, and radiation dose.
- Assessment of angiographic and clinical outcomes post-retreatment.
Main Results:
- Repeat GKS achieved angiographic obliteration in 55% of patients.
- Subtotal obliteration occurred in 6.4%, with 27.1% remaining patent.
- 126 patients showed clinical improvement or stability; 14 experienced deterioration.
Conclusions:
- Repeat GKS provides a 55% angiographic cure rate for previously treated AVMs.
- Radiation-induced changes were observed in 39% of patients, but permanent deficits were infrequent (3.6%).
- Findings support repeat GKS as a viable option for incompletely obliterated AVMs.
