What are the guidelines for using a Penumbra device in adult patients with acute ischemic stroke?

How to Use the Penumbra Device in Acute Ischemic Stroke

The Penumbra System should be used in patients with acute ischemic stroke due to large vessel occlusion presenting within 8 hours of symptom onset (or up to 24 hours in selected patients), utilizing a continuous aspiration-debulking technique through specialized reperfusion catheters connected to a vacuum source. 1

Patient Selection Criteria

Eligible patients must meet the following criteria:

• NIHSS score ≥8 indicating moderate to severe stroke 1
• Large vessel occlusion confirmed on imaging (internal carotid artery, middle cerebral artery, or basilar artery) 1
• Presentation within 8 hours of symptom onset for standard cases 1
• Patients presenting within 3 hours must be either ineligible for IV rtPA or have failed IV rtPA treatment 1
• For late-window patients (>6 hours), Alberta Stroke Program Early CT Score of at least 6 is required 2

Institutional Requirements

Critical infrastructure must be in place:

• Immediate access to cerebral angiography and experienced interventionalists with specific credentialing criteria 3
• Hospitals performing fewer than 5 thrombectomy procedures annually have significantly increased mortality risk and should transfer patients to higher-volume centers 3
• Stroke unit availability for continuous monitoring of blood pressure and neurological status post-procedure 3

Technical Procedure

The Penumbra System operates through the following mechanism:

• Position the reperfusion catheter at the proximal end of the thrombus 1
• Connect to the aspiration pump to create continuous vacuum suction 1
• Advance and withdraw the separator through the Penumbra reperfusion catheter to facilitate continuous aspiration-debulking 1
• The 3-dimensional separator can be used to enhance clot engagement and removal 1

Expected Outcomes and Monitoring

Recanalization rates and clinical outcomes:

• Partial or complete recanalization achieved in 82-87% of treated vessels 1
• Good functional outcome (mRS 0-2) occurs in 25-55% of patients depending on timing and patient selection 1, 2
• Symptomatic intracranial hemorrhage occurs in approximately 6-11% of cases 1
• 90-day mortality ranges from 14-33% depending on baseline severity 1, 2

Adjunctive Medical Management

Coordinate pharmacological therapy carefully:

• Aspirin 160-325 mg should be started within 48 hours of symptom onset but delayed 24 hours after IV thrombolysis 3
• Do NOT administer aspirin or other antiplatelet agents within 24 hours of intravenous fibrinolysis as this increases hemorrhage risk 1
• Therapeutic parenteral anticoagulation should be avoided in favor of aspirin in the acute phase 3

Critical Pitfalls to Avoid

Common errors that worsen outcomes:

• Protocol violations during thrombolysis administration significantly increase symptomatic intracranial hemorrhage risk and mortality 3
• Delaying thrombectomy to obtain chest radiography or extensive cardiac workup unless specific concerns exist (e.g., aortic dissection) 3
• Using the device in patients with abnormal coagulation (INR >1.7, PTT >45 seconds, or platelet count <100,000/µL) results in substantially lower favorable outcomes (9% vs 35%) despite similar recanalization rates 1
• Treating patients with multilobar infarctions or extensive early ischemic changes increases hemorrhage risk without benefit 1

Post-Procedure Management

Immediate post-thrombectomy care:

• Admit to stroke unit for continuous neurological and hemodynamic monitoring 3
• Serial neurological examinations using standardized tools (NIHSS) to detect early deterioration 4
• CT imaging within 24 hours to assess for symptomatic intracranial hemorrhage 1
• Blood pressure management according to stroke protocols, avoiding excessive hypertension that may increase hemorrhage risk 1