What is the recommended treatment for complete occlusion of the distal portion of the right M1 (Middle Cerebral Artery) segment of the right middle cerebral artery?

From the Guidelines

The recommended treatment for complete occlusion of the distal portion of the right M1 segment of the middle cerebral artery is immediate mechanical thrombectomy combined with intravenous thrombolysis if the patient presents within the appropriate time window. For IV thrombolysis, alteplase should be administered at 0.9 mg/kg (maximum 90 mg) with 10% given as a bolus and the remainder infused over 60 minutes, if the patient presents within 4.5 hours of symptom onset and has no contraindications, as supported by 1. Mechanical thrombectomy should be performed as soon as possible, ideally within 6 hours of symptom onset, though selected patients may benefit up to 24 hours based on perfusion imaging, as recommended by 1. During the procedure, the neurointerventionalist will use a stent retriever or aspiration catheter to remove the clot. Prior to treatment, rapid neuroimaging with CT or MRI and vessel imaging with CT angiography or MR angiography is essential to confirm the occlusion, as highlighted in 1. Blood pressure should be maintained below 185/110 mmHg before thrombolysis and during the periprocedural period. This aggressive approach is justified because M1 occlusions cause significant neurological deficits and have high morbidity if untreated, while rapid reperfusion significantly improves functional outcomes by restoring blood flow to the ischemic penumbra before irreversible damage occurs, as emphasized in 1 and 1.

Some key points to consider in the management of acute ischemic stroke due to large-vessel occlusion include:

• Differentiating between hemorrhagic and ischemic stroke to determine further management, as discussed in 1
• Visualizing the vessel occlusion to confirm the diagnosis of acute ischemic stroke and guide treatment decisions, as noted in 1
• Considering the risk/benefit ratio when treating the patient, with a focus on avoiding treatment delays and patient overselection for treatment, as highlighted in 1
• Using current challenges such as standardization and simplification of imaging protocols, management of patients who do not meet current guideline recommendations for treatment, and optimization of patient transfer, as mentioned in 1

Overall, the goal of treatment is to improve outcomes for patients with acute ischemic stroke by providing timely and effective reperfusion, as supported by the evidence from 1, 1, 1, and 1.

From the Research

Treatment Options for Complete Occlusion of the Distal Portion of the Right M1 Segment

• Mechanical thrombectomy (MT) is a recommended treatment option for acute ischemic stroke caused by complete occlusion of the distal portion of the right M1 segment of the middle cerebral artery 2.
• The use of a direct aspiration first-pass technique (ADAPT) has been shown to be effective in achieving successful recanalization of the occluded vessel 2.
• Endovascular approach, including mechanical thrombectomy, can be considered as a treatment option for patients with acute complete occlusion due to middle cerebral artery dissection 3.
• The treatment strategy for M1 subocclusive thrombus focuses on the indications for mechanical thrombectomy, and MT can be considered as a treatment option in cases of acute ischemic stroke caused by M1 subocclusive thrombus with lateral lenticulostriate artery occlusion 2.

Considerations for Treatment

• The distinction between proximal (involving the M1 segment) and distal (involving the M2 segment and beyond) middle cerebral artery occlusion has significant practical implications in patient selection for endovascular treatment 4.
• The use of intravenous alteplase alongside mechanical thrombectomy for M1 middle cerebral artery occlusion does not result in excessive intracerebral hemorrhage occurrences or clinical deterioration 5.
• The choice of treatment approach, including the use of stent-retriever or aspiration catheter, should be individualized based on the patient's specific condition and the characteristics of the occlusion 3, 5.

Clinical Outcomes

• Successful recanalization of the occluded vessel can lead to improved clinical outcomes, including full recovery or significant reduction in neurological deficits 2.
• The occurrence of intracerebral hemorrhage (ICH) is a significant factor associated with poor clinical outcome, and the risk of ICH should be carefully evaluated when selecting patients for endovascular treatment 5.