Sir,
Intracranial dural arteriovenous fistulas (DAVFs) are abnormal connections between arteries and veins located within the dura mater, without direct involvement of the brain parenchyma. These lesions are typically supplied by meningeal arteries, although pial arterial contributions may occur in some cases.[1,2] Previously, we conducted a literature review on DAVFs with pial arterial supply (PAS) and found that the most controversial issue concerning these lesions lies in their treatment strategy, particularly whether embolization of the PAS is necessary to prevent potential hemorrhagic complications.[1]
Recently, we published a retrospective clinical study specifically addressing the clinical implications of PAS in DAVFs.[2] This study was based on data from the DREAM-INI database[3] and included 1,101 patients with DAVFs. Patients were divided into two groups based on the presence or absence of PAS (with PAS, n = 259; without PAS, n = 842), and their baseline characteristics and treatment outcomes were compared accordingly. The results showed that DAVF patients with PAS were more likely to be younger, have a longer disease course, and present with fistulas located in the transverse-sigmoid sinus, tentorium, or at multiple sites. Moreover, they more frequently exhibited angioarchitectural features indicative of elevated venous hypertension, such as venous congestion and venous ectasia, compared to DAVFs without PAS. These findings are not entirely novel, as similar observations have been reported in previous studies.[4] These results suggest that increased angiogenic potential and elevated venous hypertension may be closely associated with the development of PAS. In terms of treatment outcomes, we found that DAVFs with PAS had lower cure rates, higher complication rates, and poorer prognosis compared to those without PAS. To minimize potential bias, we performed 1:1 propensity score matching between the two groups (n = 219 in each group). The results still showed that DAVFs with PAS had lower cure rates and higher complication rates compared to those without PAS. These findings suggest that DAVFs with PAS present greater therapeutic challenges compared to those without PAS.
To investigate the effect of PAS embolization on the treatment of DAVFs with PAS, a subgroup analysis was performed within this cohort, comparing patients who underwent embolization of the PAS (n = 151) with those who did not (n = 107). The results showed that the PAS embolization group had higher rates of permanent and postoperative ischemic complications compared to the nonembolization group. Although the rate of postoperative hemorrhagic complications was slightly higher in the embolization group, the difference was not statistically significant. These findings suggest that embolization of the PAS in DAVFs with PAS leads to a higher complication rate compared to cases in which the PAS is not embolized. Therefore, embolization of the PAS should be approached with caution in the routine treatment of DAVFs with PAS. However, this does not imply that the strategy should be completely abandoned, as many aspects of PAS involvement in DAVFs remain unclear. These decisions are not binary; instead, each case should be evaluated individually, taking into account its unique angioarchitecture and clinical context. Hemorrhagic complications arising from an unobliterated “pure” pial supply prior to DAVF obliteration do exist and may be catastrophic.[2,5] While current evidence and expert consensus tend to attribute PAS rupture to the absence of pial arterial embolization before complete DAVF obliteration, this causative relationship cannot be confirmed with absolute certainty.
Hence, based on current understanding, which types of DAVFs with PAS are considered to require PAS embolization, and in which cases is it deemed unnecessary? Our team believes that dural branches from pial supply, as well as very small and limited “pure” pial contributions, generally do not require embolization. However, in cases where a nidus-like structure arises from the PAS, or when the “pure” PAS supply is particularly rich and extensive, preemptive embolization of the PAS may still be necessary. This study has several inherent limitations.[2] As a single-center retrospective analysis, it is subject to potential selection bias. Additionally, the complication rate associated with PAS embolization may vary significantly depending on the operator’s experience and technical expertise. Despite these limitations, we believe that our findings reflect real-world clinical practice. Several previous studies on DAVFs with PAS have also reported that nonembolization of the PAS does not lead to a higher risk of hemorrhagic complications. The significance of our study lies in its suggestion that PAS embolization should be approached with caution in routine clinical decision-making. However, as previously noted, this does not imply that the strategy should be completely abandoned, as many aspects of PAS involvement in DAVFs remain unclear. These decisions are not binary; rather, each case should be evaluated individually, taking into account its unique angioarchitecture and clinical context—as illustrated by cases in which the absence of PAS embolization prior to complete DAVF occlusion has resulted in potential hemorrhagic complications.[2,5] Future prospective multicenter studies are warranted to better identify which subsets of DAVFs with PAS might truly benefit from complete embolization of the PAS.
Author contributions
Xin Su: Concepts, design, manuscript preparation; Yongjie Ma, Peng Zhang, Hongqi Zhang: Guarantor.
Ethical policy and institutional review board statement
Not applicable.
Data availability statement
Data sharing is not applicable to this article as no datasets were generated and/or analyzed during the current study.
Conflicts of interest
There are no conflicts of interest.
Funding Statement
Nil.
References
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Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
Data sharing is not applicable to this article as no datasets were generated and/or analyzed during the current study.