Editorial. Curative embolization for low-grade AVMs: ready for prime time?

View More View Less
  • 1 Departments of Neurosurgery and
  • | 2 Radiology, Mayo Clinic, Rochester, Minnesota
Free access

Embolization of parenchymal arteriovenous malformations (AVMs) was initially intended as palliative therapy or as an adjunct in preparation for microsurgical resection. However, with the introduction of liquid embolic agents, several groups since the mid-1990s have, in different waves, promulgated embolization as a potentially curative therapy. The possibility of curative embolization received a further boost by the introduction of modern embolic agents that allow for safer and prolonged injections while affording full penetration of the nidus.

The enthusiasm for curative embolization was tempered by the results of ARUBA (A Randomized Trial of Unruptured Brain Arteriovenous Malformations), which suggested that medical management alone was a better option (over the short- and mid-term duration of the study) for unruptured AVMs than was interventional therapy.1 In ARUBA, the majority of patients allocated to the interventional arm underwent embolization alone or in combination with radiosurgery or microsurgical resection, and many of the periprocedural complications encountered in the interventional arm were indeed related to endovascular therapy.1

A systematic review published in 2019 reported cumulative cure and complication rates of 58.3% and 24.1%, respectively, for patients who underwent embolization with the intent to cure.2 This review included many older studies that reported relatively low occlusion and high complication rates. In recent years, however, ongoing advances in the understanding of parenchymal AVM angioarchitecture and refinement of more sophisticated microcatheter techniques, including the transvenous approach, have led to progressive improvements in the safety and efficacy of embolization as a curative procedure.

Recently, in a cohort of 224 patients with Spetzler-Martin grade I or II AVMs undergoing attempted curative embolization, Baharvahdat and colleagues reported complete angiographic AVM exclusion in 92% of cases.3 Complete obliteration was achieved in most patients (62.1%) after a single endovascular treatment session, and rates of treatment-related permanent morbidity and mortality were 5% and 0.4%, respectively. In a smaller cohort of 73 patients, among whom 60% presented with ruptured AVMs, Iosif and colleagues attained curative embolization in 95% of cases, with procedure-related morbidity and mortality rates of 2.7% and 0.0%, respectively.4 In line with these results, in this issue of Neurosurgical Focus, Shariat Razavi and colleagues from Iran detail their experience with attempted curative embolization in 109 patients harboring low-grade AVMs (44% Spetzler-Martin grade I and 56% grade II).5 In the 99 patients who completed their embolization sessions, the authors observed total angiographic obliteration in 90%. Overall, complete exclusion was achieved in 59.6% of patients after a single session. Transient neurological deficits as a result of the procedure were observed in 4.6% of cases, and permanent morbidity occurred in only 1 patient (0.9%).

These results are remarkable and cannot be ignored. The question then arises: is curative embolization ready for prime time? While it is important to be open-minded and accept evolution of established therapeutic paradigms as inherent to the natural and relentless progress of medicine, it is equally critical to be cautious. This is especially true for low-grade AVMs for which alternative and safe therapeutic options such as microsurgical resection and radiosurgery can achieve similar results. Ideally, treatment selection should be tailored to AVM- and patient-specific factors to provide the best chance of cure with no associated morbidity or mortality. For grade I and II AVMs, we are very close to achieving this goal. An easy conclusion would be that randomized multicenter trials are required. The truth is that a perfect trial is neither feasible nor realistic. However, as our therapeutic options continue to evolve and improve, a well-executed registry of patient data drawn from centers of excellence around the globe may soon provide solid data to guide selection of the best treatment for AVMs.

Disclosures

Dr. Lanzino: consultant for Nested Knowledge and Superior Medical Editors.

References

  • 1

    Mohr JP, Parides MK, Stapf C, et al. Medical management with or without interventional therapy for unruptured brain arteriovenous malformations (ARUBA): a multicentre, non-blinded, randomised trial. Lancet. 2014;383(9917):614621.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 2

    Wu EM, El Ahmadieh TY, McDougall CM, et al. Embolization of brain arteriovenous malformations with intent to cure: a systematic review. J Neurosurg. 2019;132(2):388399.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 3

    Baharvahdat H, Blanc R, Fahed R, et al. Endovascular treatment for low-grade (Spetzler-Martin I-II) brain arteriovenous malformations. AJNR Am J Neuroradiol. 2019;40(4):668672.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 4

    Iosif C, de Lucena AF, Abreu-Mattos LG, et al. Curative endovascular treatment for low-grade Spetzler-Martin brain arteriovenous malformations: a single-center prospective study. J Neurointerv Surg. 2019;11(7):699705.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 5

    Shariat Razavi SA, Mirbolouk MH, Gorji R, et al. Endovascular treatment as the first-line approach for cure of low-grade brain arteriovenous malformation. Neurosurg Focus. 2022;53(1):E8.

    • Search Google Scholar
    • Export Citation

Illustration from Agosti et al. (E5). Used with permission of Mayo Foundation for Medical Education and Research. All rights reserved.

  • 1

    Mohr JP, Parides MK, Stapf C, et al. Medical management with or without interventional therapy for unruptured brain arteriovenous malformations (ARUBA): a multicentre, non-blinded, randomised trial. Lancet. 2014;383(9917):614621.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 2

    Wu EM, El Ahmadieh TY, McDougall CM, et al. Embolization of brain arteriovenous malformations with intent to cure: a systematic review. J Neurosurg. 2019;132(2):388399.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 3

    Baharvahdat H, Blanc R, Fahed R, et al. Endovascular treatment for low-grade (Spetzler-Martin I-II) brain arteriovenous malformations. AJNR Am J Neuroradiol. 2019;40(4):668672.

    • Search Google Scholar
    • Export Citation
  • 4

    Iosif C, de Lucena AF, Abreu-Mattos LG, et al. Curative endovascular treatment for low-grade Spetzler-Martin brain arteriovenous malformations: a single-center prospective study. J Neurointerv Surg. 2019;11(7):699705.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 5

    Shariat Razavi SA, Mirbolouk MH, Gorji R, et al. Endovascular treatment as the first-line approach for cure of low-grade brain arteriovenous malformation. Neurosurg Focus. 2022;53(1):E8.

    • Search Google Scholar
    • Export Citation

Metrics

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 512 512 385
PDF Downloads 351 351 275
EPUB Downloads 0 0 0