Outcomes following sonothrombolysis in severe acute ischemic stroke: subgroup analysis of the CLOTBUST trial

BACKGROUND

Sonothrombolysis is safe and may increase the likelihood of early recanalization in acute ischemic stroke patients.

AIMS

In preparation of a phase III clinical trial, we contrast the likelihood of achieving a sustained recanalization and functional independence in a post hoc subgroup analysis of patients randomized to transcranial Doppler monitoring plus intravenous tissue plasminogen activator (sonothrombolysis) compared with intravenous tissue plasminogen activator alone in the CLOTBUST trial.

METHODS

We analyzed the data from all randomized acute ischemic stroke patients with pretreatment National Institutes of Health Stroke Scale scores ≥ 10 points and proximal intracranial occlusions in the CLOTBUST trial. We compared sustained complete recanalization rate (Thrombolysis in Brain Ischemia flow grades 4-5) and functional independence (modified Rankin Scale 0-1) at 90 days. Safety was evaluated by the rate of symptomatic intracranial hemorrhage within 72 h of stroke onset.

RESULTS

Of 126 patients, a total of 85 acute ischemic stroke patients met our inclusion criteria: mean age 71 ± 11years, 56% men, median National Institutes of Health Stroke Scale 17 (interquartile range 14-20). Of these patients, 41 (48%) and 44 (52%) were randomized to intravenous tissue plasminogen activator alone and sonothrombolysis, respectively. More patients achieved sustained complete recanalization in the sonothrombolysis than in the intravenous tissue plasminogen activator alone group (38·6% vs. 17·1%; P = 0·032). Functional independence at 90 days was more frequently achieved in the sonothrombolysis than in the intravenous tissue plasminogen activator alone group (37·2% vs. 15·8%; P = 0·045). Symptomatic intracranial hemorrhage rate was similar in both groups (4·9% vs. 4·6%; P = 1·00).

CONCLUSIONS

Our results point to a signal of efficacy and provide information to guide the subsequent phase III randomized trial of sonothrombolysis in patients with severe ischemic strokes.

Surgical treatment of large and giant cavernous carotid aneurysms

Cavernous carotid aneurysms (CCAs) are uncommon pathologic entities. Extradural place and the skull base location make this type of an aneurysm different in clinical features and treatment techniques. Direct aneurysm clipping is technically difficult and results in a significant postoperative neurological deficit. Therefore, several techniques of indirect surgical treatment were developed with different surgical outcomes, such as proximal occlusion of internal carotid artery (ICA) or trapping with or without bypass (superficial temporal artery-middle cerebral artery bypass or high-flow bypass). High-flow bypass with proximal ICA occlusion seems to be the most appropriate surgical treatment for CCA because of the high rate of symptom improvement, aneurysm thrombosis, and minimal postoperative complications. However, in cases of CCA presented with direct carotid-cavernous fistula, the appropriate surgical treatment is high-flow bypass with aneurysm trapping, which the fistula can be obliterated immediately after surgery.

Recurrent Embolic Stroke Caused by Large Cavernous Carotid Aneurysm: Stroke Recurrence Prevention with High-Flow Bypass Followed by Proximal Occlusion

Intracranial aneurysms may cause embolic stroke. Medical or surgical management is selected on an individual basis, as the optimal treatment strategy has not been established. A 79-year-old woman with a large cavernous carotid aneurysm suffered repeated embolic stroke after enlargement and partial thrombosis of the aneurysm, in spite of antiplatelet therapy. Coil embolization of the primitive trigeminal artery and ligation of the internal carotid artery (ICA) at the cervical portion followed by high-flow bypass from the cervical external carotid artery to the middle cerebral artery were performed. The aneurysm was thrombosed, and prevention of further stroke was achieved. Acute enlargement and thrombosis of large or giant cavernous carotid aneurysm may cause repeated embolic stroke, and requires emergent exclusion of the aneurysm from circulation by proximal ICA occlusion together with distal revascularization before devastating embolic stroke occurs.

Cerebral Revascularization for the Management of Symptomatic Pure Arterial Malformations

Background: Pure arterial malformations (PAMs) are extremely rare abnormalities defined as dilated, overlapping, and tortuous arteries with a coil-like appearance in the absence of venous components. Over the last half century, only seven published reports have described cases of patients with PAMs who received treatment. Methods: Here, we report two cases of women with PAMs who received surgical treatment, and we present a systematic review of the literature. We searched the PubMed, Embase, Web of Science, and Medline databases (up until October 1, 2021) for relevant publications. We performed independent-sample t-tests and Fisher's exact tests to compare continuous and categorical characteristics among the available cases. Results: Our first patient was a 43-year-old woman with PAM of the left internal carotid artery (ICA), who received an ICA-radial artery (RA)-M2 bypass. Post-operative digital subtraction angiography (DSA) revealed the disappearance of the left ICA PAM without ischemic events during follow-up. The second patient was a 53-year-old woman with PAMs of the right ICA and posterior cerebral artery. The P1 lesion was treated by proximal occlusion combined with a superficial temporal artery-P2 bypass. During the 12-month follow-up period, the size of the PAMs decreased significantly as indicated by the post-operative DSA showing the absence of hemorrhages. Our systematic review, which includes 56 PAMs, shows that the reported PAMs were more common in the anterior circulation (33/56, 58.9%) than in the posterior circulation (11/56, 19.7%). Bilateral PAMs were more likely to affect bilateral anterior cerebral arteries (ACA) (ACAbilateral vs. ACAunilateral: 63.6 vs. 26.2%, p = 0.02). In addition, PAMs involving the anterior circulation were likely to affect multiple arteries (anteriormulti vs. posteriormulti: 30.3 vs. 0%, p = 0.038). Conclusion: We found very few reports on treated PAMs; further studies with large sample sizes and long follow-up periods are required to explore the appropriate treatment strategy for PAMs.