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Intra-arterial Treatment for Basilar Artery Occlusion.

Intra-arterial Treatment for Basilar Artery Occlusion To the Editor We thank van Houwelingen et al1 for their retrospective study exploring the efficacy and safety of intraarterial (IA) treatment in basilar artery occlusion (BAO). They reported adequate recanalization and favorable outcomes in the cohort receiving IA therapy after BAO. We commend the authors’ stringent diagnostic workup to confirm the presence of BAO. However, we note that the mean age of the patient cohort was younger than 60 years, and given that this age demographic harbors fewer comorbidities compared with the older than 65 age group where stroke incidence is higher, this confers a favorable outcome regardless of the intervention. Furthermore, although some prestroke comorbidities have been accounted for, atrial fibrillation has not been considered. In patients with atrial fibrillation receiving systemic antithrombotic therapy, IA thrombolysis is contraindicated owing to the increased risk for an adverse intracranial hemorrhage,2 thus leaving stenting as the only suitable option. Therefore, the very nature of judgement-based treatment allocation leaves the door open for potential selection bias that may significantly affect outcome measures. Although effort has been taken to categorize patency according to vessel subtype, inclusion of multiple criteria within the same category overlooks the varying pathophysiology underlying reduced patency. For example, no patency of vertebral arteries was defined as either complete occlusion, posterior inferior cerebellar artery termination, aplasia or vessel hypoplasia, or high-grade stenosis of more than 70%. Stenotic vessels are commonly caused by platelet plugs associated with atherosclerotic plaque rupture and are less likely to be successfully managed by IA urokinase alone.2 Alternative methods of stratification may eliminate this bias. This retrospective study1 covers a period of 9 years, a time in which stent retriever technology has considerably evolved. In particular, the Trevo device has been associated with better recanalization rates and fewer complications compared with Merci.3 Given the inconsistencies in the device used and the fact that the Trevo device was used in most cases in this study, there may be an overestimation of benefit derived from this treatment modality as a consistent single device was not used. Restoration of cerebral perfusion alone may be insufficient to produce favorable outcomes4; thus, while initial results from this study are promising, it should prompt prospective trials with a larger patient cohort to evaluate the longterm benefit of IA therapy in acute BAO.