Response to Letter by Dai et al
We deeply appreciate the interest of Dr Dai and his colleagues in our study. Certainly, differences in stroke etiology exist between Asian and European populations. The higher incidence of intracranial vessel stenosis in the Asian population implicates that stent placement for acute vessel recanalization might be the treatment of choice for acute stroke in these patients. However, this assumption has to be proofed by future studies. Additionally, it will be a challenge to assess the underlying cause of a cerebral artery occlusion in the acute situation, which might be possible in the future considering recent developments in high-field MRI of acute stroke.
Dr Dai and colleagues mentioned that an open vessel might not always be a good thing and that strokes caused by cardioembolism may have a higher risk of hemorrhagic transformation. These concerns appear to be unsubstantiated: retrospective analysis of 2066 stroke patients confirmed that recanalization is strongly associated with good outcome and decreased mortality after acute ischemic stroke.1 Moreover, in 294 patients treated at our institution, stroke etiology was no predictor of symptomatic intracranial hemorrhage (sICH), and in contradiction to Dr Dai’s concerns, failed recanalization was associated with sICH.2
Of the twelve patients reported in the present study who were treated by stent placement,3 six patients had local thrombosis of an intracranial artery and six patients had embolic strokes. Mortality was 33.3% for both groups and good outcome (mRS 0 to 2) was achieved in 2/6 patients with embolic stroke and in 1/6 patients with local intracranial thrombosis. It would be a mistake to recommend stent placement only for patients experiencing intracranial artery stenosis and subsequent local thrombosis.
Furthermore, Dr Dai et al are concerned that antithrombotic therapy after stent placement might complicate the setting for mechanical heart valve replacement. In our opinion, fast recanalization of the acutely occluded cerebral artery has absolute priority and should be performed by stent placement if necessary. In case the patient becomes a candidate for cardiac surgery afterward, antithrombotic therapy precludes neither the surgical treatment nor the antithrombotic prophylaxis even in combination with anticoagulation.
To conclude, in our experience of more than 600 acute stroke patients treated by endovascular approach, stent placement is not the first treatment option but a promising complement in the rapidly increasing armamentarium of interventional neuroradiology for fast vessel recanalization.4,5 However, future studies have to evaluate the most effective combination of treatments for every site and type (eg, length of occlusion6) of cerebral artery occlusion.
Rha JH, Saver JL. The impact of recanalization on ischemic stroke outcome: a meta-analysis. Stroke. 2007; 38: 967–973.
Brekenfeld C, Remonda L, Nedeltchev K, Arnold M, Mattle HP, Fischer U, Kappeler L, Schroth G. Symptomatic intracranial haemorrhage after intra-arterial thrombolysis in acute ischaemic stroke: assessment of 294 patients treated with urokinase. J Neurol Neurosurg Psychiatry. 2007; 78: 280–285.
Brekenfeld C, Schroth G, Mattle HP, Do DD, Remonda L, Mordasini P, Arnold M, Nedeltchev K, Meier N, Gralla J. Stent placement in acute cerebral artery occlusion: use of a self-expandable intracranial stent for acute stroke treatment. Stroke. 2009; 40: 847–852.
Brekenfeld C, Tinguely P, Schroth G, Arnold M, El-Koussy M, Nedeltchev K, Byrne JV, Gralla J. Percutaneous transluminal angioplasty and stent placement in acute vessel occlusion: evaluation of new methods for interventional stroke treatment. AJNR. 2009, epub ahead of print. March 19, 2009.
Gralla J, Burkhardt M, Schroth G, El-Koussy M, Reinert M, Nedeltchev K, Slotboom J, Brekenfeld C. Occlusion length is a crucial determinant of efficiency and complication rate in thrombectomy for acute ischemic stroke. AJNR Am J Neuroradiol. 2008; 29: 247–252.