TO THE EDITOR: I read with great interest the observational retrospective study by Razavi et al.1 (Razavi SAS, 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). In this study, the authors aimed to evaluate the efficacy and safety of endovascular treatment (EVT) for patients with low-grade brain arteriovenous malformation (bAVM). For the purpose of the analysis, patients were divided into two major groups: ruptured and unruptured. Demographic and clinical information, including complete lesion exclusion, procedural complications, and long-term clinical outcomes, were compared between the two groups. The authors concluded that EVT can be the first-line treatment for patients with low-grade bAVM, with high cure and low morbidity rates. These findings are in general agreement with neurosurgeons’ clinical experiences. However, there are still some doubts about the methods and results. Given this, I hope to communicate with the aforementioned authors.
To begin, in the Patient Selection section, the authors mentioned that "significant hemorrhagic complications were considered if the patient experienced a new neurological deficit (ND) or if he/she required surgery." Regarding this point, why was it possible to determine the occurrence of severe bleeding complications based on the presence of new neurological deficits in these patients? The authors mentioned earlier that bleeding was mainly determined on the basis of findings on CT or MRI, which seems to be a contradiction.
Second, in the Endovascular Procedure section, several liquid embolic agents, including Onyx-18 (Medtronic), Squid-18 (Emboflu), and Glubran 2 (GEM), were administered to patients. I wondered whether there are criterion standards for the selection of liquid embolic agents at your clinical practice.
Third, in Table 1, I noted a higher incidence of epilepsy in the unruptured group. Is it necessary to disclose the rate of seizure improvement in these patients during the postoperative period? In general, microsurgery results in a higher rate of seizures. Lower complete seizure-free rates after stereotactic radiosurgery (SRS) or EVT have been reported in the literature.2
Last but not least, EVT combined with SRS significantly decreases the bAVM obliteration rate,3–5 which suggests the importance of EVT in the treatment of low-grade bAVMs. Overall, the current study negates the conclusion obtained by A Randomized Trial of Unruptured Brain Arteriovenous Malformations (ARUBA), although the study was retrospective. The authors also highlighted both the necessity and safety of EVT for low-grade bAVMs.
Disclosures
The author reports no conflict of interest.
References
- 1↑
Razavi SAS, 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.
- 2↑
Mamaril-Davis JC, Aguilar-Salinas P, Avila MJ, Nakaji P, Bina RW. Complete seizure-free rates following interventional treatment of intracranial arteriovenous malformations: a systematic review and meta-analysis. Neurosurg Rev. 2022;45(2):1313–1326.
- 3↑
Xu F, Zhong J, Ray A, Manjila S, Bambakidis NC. Stereotactic radiosurgery with and without embolization for intracranial arteriovenous malformations: a systematic review and meta-analysis. Neurosurg Focus. 2014;37(3):E16.
- 4
Russell D, Peck T, Ding D, et al. Stereotactic radiosurgery alone or combined with embolization for brain arteriovenous malformations: a systematic review and meta-analysis. J Neurosurg. 2018;128(5):1338–1348.
- 5↑
Jiang X, Zhao Z, Zhang Y, Wang Y, Lai L. Preradiosurgery embolization in reducing the postoperative hemorrhage rate for patients with cerebral arteriovenous malformations: a systematic review and meta-analysis. Neurosurg Rev. 2021;44(6):3197–3207.
