Thrombolysis of Basilar Artery Occlusion—Intra-Arterial or Intravenous: Is There Really No Difference?

Abstract

With great interest we read the meta-analysis on the therapy of basilar artery occlusion (BAO) by Lindsbergh and Mattle 1 published in the March issue of Stroke. The authors compared the pooled data from 13 retrospective studies (3 studies including 76 patients treated by intravenous thrombolysis [IVT], and 10 studies including 344 patients treated by intra-arterial thrombolysis [IAT]) in patients with BAO. The authors draw the conclusions that the route of drug delivery for treatment of BAO does not make a difference in clinical outcome and that the odds for survival without a handicap improve equally after IVT and IAT. We agree with the authors that the recanalization success is the conditio sine qua non for a favorable neurological outcome in BAO. 1,2 The conclusions, however, raise some concerns. As stated by the authors, 1 the recanalization rate of IVT is only 53%, probably owing to the unselective way of delivery and large thrombus load in extended BAO. The recanalization rate of IAT is reported to be 65%. 1 The endovascular approach, however, offers besides IAT with a recanalization rate up to 74% 2 the opportunity of mechanical recanalization. Preliminary results have shown recanalization rates up to 100% and favorable clinical outcome (ie, independence in daily life) in up to one-third of the patients by using different devices for mechanical recanalization alone or in combination with IAT. 3 Furthermore, high-grade arteriosclerotic stenosis of the extra-and intracranial vertebrobasilar circulation is a frequent etiology of BAO and a common cause of early reocclusion after thrombolysis. Thus, the IA approach allows for simultaneous acute treatment of the BAO and prevention of early reocclusion of the basilar artery by percutaneous transluminal angioplasty with or without stenting.Fifty of 76 patients treated by IVT were derived from Lindsberg's own study published in JAMA in 2004. 4 In this study, BAO has been diagnosed by the clinical syndrome combined with time-of-flight MR angiography performed on a 1.5-T scanner. Intra-arterial angiography was available in only 5 of 50 patients. It is well known that MR angiography including raw images is insensitive to slow and low residual flow and may show discontinuity (skip sign) attributable to technical reasons. 5 Therefore, it remains ambiguous whether the basilar artery was completely or only partially occluded with a potentially life-saving residual flow maintaining the perfusion of the brain stem in the patients of Lindsberg's study. Consequently, a potential bias of this pivotal study, which has driven the results of the IVT group, might have introduced a bias into the meta-analysis.From our point of view, the IA approach used for highly selective thrombolysis or mechanical recanalization remains the therapy of first choice in BAO. The primary IV use of glycoprotein IIb/IIIa receptor inhibitors or recombinant tissue plasminogen activator may be helpful for bridging the interval until referral to an experienced neurointerventional stroke center as sugges...

Therapy of Acute Basilar Artery Occlusion

“…2 Since then, an open discussion among specialists has begun on whether to treat patients with BAO intraarterially or intravenously and whether a randomized controlled trial is feasible. [13][14][15][16][17][18][19][20][21] In a multicenter observational study it has recently been shown that the bridging concept, using combined treatment with IA rt-PA and IV platelet glycoprotein IIb/IIIa receptor inhibitors and additional percutaneous transluminal angioplasty/stenting in case of severe residual stenosis after IAT, might improve neurological outcome compared to IAT with rt-PA alone. 9 In this monocenter retrospective analysis, we compared the treatment of acute BAO with IAT alone and the combined approach of an IV glycoprotein IIb/IIIa inhibitor plus IA rt-PA treatment (bridging).…”

Endovascular therapy for acute basilar artery occlusion: a review of the literature

“…Critics of IAT claim that procedural risks and expenses cannot currently be justified 33. Proponents suggest higher rates of recanalization with IAT and potentially lower rates of symptomatic intracranial hemorrhage 1 4 5. Indeed, transcranial Doppler monitoring suggests recanalization in only 30% of cases of basilar artery occlusion treated with IVT 34.…”

“…In the acute presentation, altered levels of consciousness, dysarthria, paresis, hemiplegia or tetraplegia, ataxia, cranial nerve deficits and supranuclear occulomotor disturbances are the commonest presenting signs. Although prognosis is variable, basilar occlusion has traditionally been thought to be associated with a poor outcome 1 4 5. More recently there has been an emphasis on acute therapeutic recanalization to re-establish perfusion, with several case series suggesting a reduction in mortality and improved functional outcomes following thrombolytic treatment.…”

Endovascular Approaches to Acute Stroke, Part 2: A Comprehensive Review of Studies and Trials

“…However, this analysis had many limitations, including the fact that most the patients with IV thrombolysis were evaluated by time-of-flight MR angiography, which is less sensitive to low-flow states. 39 The Basilar Artery International Cooperation Study (BASICS) was a prospective observational multicenter international registry of consecutive patients presenting with a symptomatic and radiologically confirmed BAO (by CT angiography, MR angiography, or conventional angiography) and represents the largest data base on BAO to date. 40 The registry was started in November 2002 and was completed in September 2007, with a total of 624 patients enrolled at 49 centers worldwide.…”