Direct Angioplasty for Acute Occlusion of Intracranial Artery

We have read with interest an article by Nakano et al published in the AJNR regarding direct percutaneous transluminal angioplasty for acute middle cerebral artery (MCA) occlusion (1). The authors report their experience with using direct percutaneous angioplasty (PTA) as the sole means of treating 10 patients with acute MCA occlusion when initial CT scans show early ischemic changes, lenticulostriate artery (LCA) involvement, or both. The authors' rationale for choosing direct PTA alone to establish blood flow without using thrombolysis is based on the high risk of hemorrhagic complications in this group of patients. The authors believe that such a risk can be reduced by avoiding thrombolytic therapy. The angiographic success rate in their patients was relatively high (80%), and there were no hemorrhagic complications; however, the rationale for their method becomes debatable despite a high rate of angiographic success without hemorrhagic complications.

We wonder whether the authors may have overlooked the fundamental disease process that causes hemorrhagic complications during acute ischemic stroke. Patients with early ischemic findings on initial CT scans have a high risk of hemorrhage after reestablished blood flow primarily because of the high incidence of reperfusion of irreversibly damaged ischemic tissue. The thrombolytic agent can contribute to hemorrhagic complications (ie, reperfusion of dead tissue), but is not the primary cause. The most effective way to prevent such complications is either to avoid reperfusion of irreversibly damaged tissue or to recanalize the occluded vessel as early as possible. In some patients, the blood flow of the cortex in the distal MCA territory can be rescued by recanalization of the occluded M1 segment with direct angioplasty. Nonetheless, angioplasty alone will not dissolve the clot or reestablish the blood flow effectively, particularly in the perforators, but will further propagate the clot distally. Therefore, the relatively low rates of hemorrhage and clinical recovery suggest that their technique of performing angioplasty alone may not be as effective in reestablishing blood flow. If the authors believe that early ischemic findings on the initial CT scan can suggest irreversibly damaged tissue and a high risk of hemorrhage, then early interventional treatment, including PTA, should not be performed in patients who have such findings.

One important question regarding the treatment of acute stroke is whether we are treating reversible ischemia. Our previous reports suggest that reversibility of ischemic tissue can be assessed by SPECT of pretreatment CBF, which can help in the selection of appropriate patients for thrombolysis by reducing hemorrhagic complications and improving outcome (2, 3). Our previous experience also suggests that a combination of thrombolysis and angioplasty is effective in failed thrombolysis cases or reocclusion cases (4). We strongly believe that angioplasty is an effective option in reperfusion therapy for acute ischemic stroke, and can shorten the duration of ischemia and improve the success rate of recanalization. Most importantly, the purpose of angioplasty should be to improve the neurologic symptoms of stroke patients by increasing CBF, not to improve angiographic results.