Intravenous low-dose native tissue plasminogen activator for distal embolism in the middle cerebral artery divisions or branches: a pilot study

Multiphase adjuvant neuroprotection: A novel paradigm for improving acute ischemic stroke outcomes

While several large pivotal clinical trials recently revealed a substantial benefit of endovascular thrombectomy for acute ischemic stroke (AIS) caused by large-vessel occlusion, many patients still experience mediocre prognosis. Enlargement of the ischemic core, failed revascularization, incomplete reperfusion, distal embolization, and secondary reperfusion injury substantially impact the salvaging of brain tissue and the functional outcomes of AIS. Here, we propose novel concept of “Multiphase Adjuvant Neuroprotection” as a new paradigm that may help guide our search for adjunctive treatments to be used together with thrombectomy. The premise of multiphase adjuvant neuroprotection is based on the diverse and potentially nonoverlapping pathophysiologic mechanisms that are triggered before, during, and after thrombectomy therapies. Before thrombectomy, strategies should focus on preventing the growth of the ischemic core; during thrombectomy, improving recanalization while reducing distal embolization and maximizing reperfusion are of significant importance; after reperfusion, strategies should focus on seeking targets to reduce secondary reperfusion injury. The concept of multiphase adjuvant neuroprotection, wherein different strategies are employed throughout the various phases of clinical care, might provide a paradigm to minimize the final infarct size and improve functional outcome in AIS patients treated with thrombectomy. With the success of thrombectomy in selected AIS patients, there is now an opportunity to revisit stroke neuroprotection. Notably, if the underlying mechanisms of these neuroprotective strategies are identified, their role in the distinct phases will provide further avenues to improve patient outcomes of AIS.

Reperfusion Therapy for Acute Middle Cerebral Artery Trunk Occlusion. Direct Percutaneous Transluminal Angioplasty Versus Intra-arterial Thrombolysis

SUMMARY

The purpose of this study was to test the hypothesis that direct percutaneous transluminal angioplasty (PTA) might reduce the incidence of haemorrhagic complications and might improve recanalization rate and clinical outcome as compared with intra-arterial (IA) thrombolysis in patients with acute middle cerebral artery (MCA) trunk occlusion. A total of 70 patients with acute MCA trunk occlusion were treated with IA reperfusion therapy. Thirty-six patients were treated with IA thrombolysis alone. In the other 34 patients, direct PTA was selected as the first choice of the treatment and subsequent thrombolysis was added if necessary for distal embolization. The modified Rankin scale (mRS) was used to assess clinical outcome at 90 days. As compared with IA thrombolysis, direct PTA provided significant increase in the rates of partial or complete recanalization (63.9 vs 91.2%, p < 0.01) and decrease in the incidence of large parenchymal hematoma with neurological deterioration (19.4% vs 2.9%, p=0.03). Despite such favorable effects, direct PTA did not improve the rate of a favorable outcome (mRS score 0 or 1, 41.7% for the IA thrombolysis group vs 52.9% for the PTA group, p=0.48). However, outcome classified in terms of independence (mRS score </= 2) was significantly better in the PTA group (73.5%) than the IA thrombolysis group (50.0%, p=0.04). In patients with acute MCA trunk occlusion, as compared with IA thrombolysis, direct PTA improved recanalization rate and reduced serious haemorrhagic complications, resulting in a significant increase in independent patients.

Anterior cerebral artery emboli in combined intravenous and intra-arterial rtPA treatment of acute ischemic stroke in the IMS I and II trials

BACKGROUND AND PURPOSE

Anterior cerebral artery (ACA) emboli may occur before or during fibrinolytic revascularization of middle cerebral artery (MCA) and internal carotid artery (ICA) T occlusions. We sought to determine the incidence and effect of baseline and new embolic ACA occlusions in the Interventional Management of Stroke (IMS) studies.

MATERIALS AND METHODS

Case report forms, pretreatment and posttreatment arteriograms, and CTs from 142 subjects entered into IMS I & II were reviewed to identify subjects with baseline ACA occlusion, new ACA emboli occurring during fibrinolysis, subsequent CT-demonstrated infarction in the ACA distribution, and to evaluate global and lower extremity motor clinical outcome.

RESULTS

During M1/M2 thrombolysis procedures, new ACA embolus occurred in 1 of 60 (1.7%) subjects. Baseline distal emboli were identified in 3 of 20 (15%) T occlusions before intra-arterial (IA) treatment, and new posttreatment distal ACA emboli were identified in 3 subjects. At 24 hours, 8 (32%) T occlusions demonstrated CT-ACA infarct, typically of small volume. Infarcts were less common following sonography microcatheter-assisted thrombolysis compared with standard microcatheter thrombolysis (P = .05). Lower extremity weakness was present in 9 of 10 subjects with ACA embolus/infarct at 24 hours. The modified Rankin 0 to 2 outcomes were achieved in 4 of 25 (16%) subjects with T occlusion overall, but in 0 of 10 subjects with distal ACA emboli or ACA CT infarcts (P = .07).

CONCLUSIONS

With IV/IA recombinant tissue plasminogen activator treatment for MCA emboli, new ACA emboli are uncommon events. Distal ACA emboli during T-occlusion thrombolysis are not uncommon, typically lead to small ACA-distribution infarcts, and may limit neurologic recovery.