What is the most appropriate management for a patient with a 12-hour history of lower limb weakness, normal vitals, normal coagulation profile, and normal platelet count, with imaging showing a small to moderate ischemic core and proximal anterior circulation occlusion?

Management of Acute Ischemic Stroke at 12 Hours with Proximal Anterior Circulation Occlusion

Combined tPA and mechanical thrombectomy (Option C) is the most appropriate management for this patient, provided advanced perfusion imaging confirms salvageable tissue meeting DAWN or DEFUSE-3 criteria. 1, 2

Rationale for Combined Therapy at 12 Hours

The American Heart Association recommends combined tPA and mechanical thrombectomy for patients with proximal anterior circulation occlusion and a small to moderate ischemic core at this time point, with treatment decisions based on tissue viability rather than time alone. 1 At 12 hours from onset, this patient falls within the extended window for mechanical thrombectomy when salvageable tissue is present, but beyond the standard 4.5-hour window for tPA alone. 1

The evidence strongly supports combined therapy over thrombectomy alone:

• Most patients in positive thrombectomy trials received IV tPA in addition to mechanical thrombectomy, with 83.7% in MR CLEAN and 91.5% in ESCAPE receiving combined therapy. 1
• The MR CLEAN trial demonstrated benefit specifically in patients who received both IV tPA and mechanical thrombectomy, with 445 of 500 patients receiving this combined approach. 1
• The ESCAPE trial showed an adjusted OR of 1.67 for improved functional outcomes with mechanical thrombectomy in patients up to 12 hours from onset with small infarct cores and proximal anterior circulation occlusions. 1

Critical Imaging Requirements Before Proceeding

Advanced perfusion imaging is essential to confirm salvageable tissue before treatment at 12 hours. 1, 2 The patient must meet either:

DAWN Criteria 1, 2:

• Age <80 years with NIHSS ≥10 and core <31 mL, OR
• NIHSS ≥20 and core <51 mL

DEFUSE-3 Criteria 1, 2:

• Ischemic core <70 mL
• Mismatch ratio ≥1.8
• Mismatch volume ≥15 mL

The 2018 AHA/ASA guidelines emphasize that only DAWN or DEFUSE-3 eligibility criteria should be used for patient selection beyond 6 hours, and these should be strictly adhered to in clinical practice. 3

Why Not the Other Options?

Option A (tPA alone): Inappropriate because the patient is beyond the 4.5-hour window for standalone IV thrombolysis, and the presence of a proximal anterior circulation occlusion requires mechanical intervention for optimal outcomes. 3

Option B (Manual embolectomy alone): Suboptimal because the evidence demonstrates superior outcomes with combined therapy rather than thrombectomy alone in patients who are eligible for both treatments. 1

Option D (Observe): Unacceptable because this patient has a salvageable limb with a small to moderate ischemic core and proximal occlusion—exactly the population shown to benefit from intervention in the DAWN and DEFUSE-3 trials. 3, 1

Technical Execution

The goal of mechanical thrombectomy should be TICI 2b/3 reperfusion to maximize functional outcomes. 3, 1 The 2018 AHA/ASA guidelines specify this as a Class I, Level A recommendation. 3

Minimize door-to-groin puncture time, with the ESCAPE trial achieving a median groin puncture time of 110 minutes. 1 Stent retrievers achieved 59% TICI 2b/3 recanalization in MR CLEAN. 1

Critical Contraindications to Avoid

Do not proceed with thrombectomy if imaging demonstrates: 1, 2

• ASPECTS of 0
• No perfusion mismatch
• Large established infarct core >70 mL by DEFUSE-3 criteria
• Failure to meet DAWN criteria

Avoid delaying treatment for unnecessary testing beyond confirming blood glucose and obtaining essential vascular imaging. 1

Post-Procedure Management

Maintain blood pressure ≤180/105 mmHg for 24 hours after thrombectomy to optimize outcomes and reduce hemorrhagic complications. 1, 2 Close monitoring for hemorrhagic transformation in the immediate post-procedure period is essential. 1