Management of Acute Ischemic Stroke at 12 Hours with Proximal Anterior Circulation Occlusion
For this patient presenting at 12 hours with a small to moderate ischemic core and proximal anterior circulation occlusion, the most appropriate management is combined tPA and mechanical thrombectomy (Option C). 1
Rationale for Combined Therapy Over Mechanical Thrombectomy Alone
The landmark thrombectomy trials that established efficacy included 83.7-91.5% of patients who received IV tPA alongside mechanical intervention, and subgroup analyses demonstrated benefit with this combined approach. 1, 2
In the MR CLEAN trial, 445 of 500 patients (89%) received IV tPA in addition to mechanical thrombectomy, establishing the evidence base for combined therapy rather than thrombectomy alone. 1
The ESCAPE trial, which specifically studied patients up to 12 hours from onset, showed an adjusted odds ratio of 1.67 (95% CI 1.21-2.30) for improved functional outcomes with combined therapy versus medical management alone. 1
Patients eligible for both IV alteplase and endovascular thrombectomy should receive both treatments in parallel, with IV thrombolytics initiated while simultaneously preparing the angiography suite. 2
Why This Patient Qualifies at 12 Hours
At 12 hours, this patient is beyond the standard 4.5-hour window for tPA alone but within the extended window for mechanical thrombectomy when salvageable tissue is present. 1
The presence of a "small to moderate ischemic core" indicates salvageable tissue, which is the critical determinant for treatment eligibility at this time point—not the time window alone. 1
The American Heart Association recommends combined tPA and mechanical thrombectomy for patients with proximal anterior circulation occlusion and a small to moderate ischemic core, provided they meet specific imaging criteria for salvageable tissue. 1
For patients beyond 6 hours from onset, mechanical thrombectomy is beneficial when small infarct cores and proximal anterior circulation occlusions are present, as demonstrated by trials like ESCAPE and DEFUSE-3. 1, 3
Critical Imaging Requirements
Advanced perfusion imaging should confirm salvageable tissue before proceeding with treatment at 12 hours. 1, 3
The patient must demonstrate either:
DAWN criteria: Clinical-imaging mismatch with age <80 years, NIHSS ≥10, and core <31 mL, OR NIHSS ≥20 and core <51 mL. 1
DEFUSE-3 criteria: Ischemic core <70 mL, mismatch ratio ≥1.8, and mismatch volume ≥15 mL. 1, 4
Technical Implementation
Do not wait to assess clinical response to IV thrombolytics before proceeding to thrombectomy—every minute of delay reduces the probability of favorable outcome by approximately 10.6% per 30-minute increment. 2
The patient should receive IV alteplase in the emergency department while the interventional team is mobilized simultaneously to minimize delays. 2
Door-to-groin puncture time should be minimized, with target times under 110 minutes from arrival. 1, 2
Stent retrievers are the preferred device, achieving TICI 2b/3 recanalization in 59-87.8% of cases. 1, 2
The procedural goal should be TICI 2b/3 reperfusion to maximize functional outcomes. 1, 3
Post-Procedure Management
Blood pressure should be maintained at ≤180/105 mmHg for 24 hours after thrombectomy to optimize outcomes and reduce hemorrhagic complications. 1
Close monitoring for hemorrhagic transformation and other complications in the immediate post-procedure period is essential. 1
Critical Pitfalls to Avoid
Proceeding with thrombectomy is contraindicated if imaging shows ASPECTS of 0, no perfusion mismatch, or a large established infarct core (>70 mL by DEFUSE-3 criteria or not meeting DAWN criteria). 1, 3