Endovascular Approaches to Acute Stroke

Abstract

Stroke remains the third most common cause of death in industrialized nations, after myocardial infarction and cancer, and the single most common reason for permanent disability [1].

Appendices

Appendix

MGH Protocols for Endovascular Therapy (Pharmacological and/or Mechanical) in Acute Stroke

13.2.1 IA Inclusion Criteria

• A significant neurologic deficit expected to result in long-term disability, and attributable to large vessel occlusion (basilar, vertebral, internal carotid or MCA M1 or M2 branches).

• Noncontrast CT scan without hemorrhage or well-established infarct.

• Acute ischemic stroke symptoms with onset or last known well, clearly defined. Treatment within 8 h of established, nonfluctuating deficits due to Anterior Circulation (carotid/MCA) stroke. The window of opportunity for treatment is less well defined in posterior circulation (Vertebral/Basilar) ischemia, and patients may have fluctuating, reversible ischemic symptoms over many hours or even days and still be appropriate candidates for therapy.

13.2.2 Absolute Exclusion Criteria

• Hemorrhage or well-established acute infarct on CT involving greater than 1/3 of the affected vascular territory.

• CNS lesion with high likelihood of hemorrhage s/p chemical thrombolytic agents (e.g., brain tumors, abscess, vascular malformation, aneurysm, contusion).

• Established bacterial endocarditis.

13.2.3 Relative Contraindications

• Mild or rapidly improving deficits.

• Significant trauma within 3 months*.

• CPR with chest compressions within past 10 days*.

• Stroke within 3 months.

• History of ICH; or symptoms suspicious for subarachnoid hemorrhage.

• Major surgery within past 14 days*.

• Minor surgery within past 10 days, including liver and kidney biopsy, thoracocentesis, lumbar puncture*.

• Arterial puncture at a noncompressible site within past 14 days (see below for femoral artery puncture)*.

• Pregnant (up to 10 days postpartum) or nursing woman*.

• Suspected Bacterial endocarditis.

• Gastrointestinal, urologic, or respiratory hemorrhage within past 21 days*.

• Known bleeding diathesis (includes renal and hepatic insufficiency)*.

• Life expectancy <1 year from other causes.

• Peritoneal dialysis or hemodialysis*.

• PTT >40 s; platelet count <100,000*.

• INR > 1.7 (PT>15 if no INR available) with or without chronic oral anticoagulant use*.

• Seizure at onset of stroke (This relative contraindication is intended to prevent treatment of patients with a deficit due to postictal Todd’s paralysis or with seizure due to some other CNS lesion that precludes thrombolytic therapy. If rapid diagnosis of vascular occlusion can be made, treatment may be given.)**.

• Glucose <50 or >400 (This relative contraindication is intended to prevent treatment of patients with focal deficits due to hypo- or hyperglycemia. If the deficit persists after correction of the serum glucose, or if rapid diagnosis of vascular occlusion can be made, treatment may be given.)**.

* Items marked with an asterisk may not be exclusions for mechanical thrombolysis with or without ­limited dose chemical agents.

** In the setting of suspected stroke mimics (e.g., seizure with postictal state, hypoglycemia, hyperglycemia, etc), careful analysis of CT angiography and MRI may exclude these states by identifying a vascular occlusion or a DWI/FLAIR lesion consistent with a cerebral infarct. Note should be made that certain stroke mimics (e.g., prolonged seizures) may result in changes on DWI/FLAIR MRI, but as opposed to cerebral ischemia, these changes are typically limited to the gray matter.

13.2.4 Prethrombolysis Work-Up

• Temperature, pulse, BP, respiratory rate.

• Physical exam/neurologic exam including NIHSS.

• 12-lead EKG.

• CBC with platelets, Basic Metabolic (electrolytes, BUN/creatinine, glucose) and Hepatic function Panel, PT (INR), PTT, ESR, fibrinogen. Blood for type and screen.

• Urine or blood pregnancy test in women of child-bearing potential.

• Consider Hypercoagulable Panel in young patients without apparent stroke risk factors.

13.2.5 Prethrombolysis Management

• Start supplementary oxygen. Treat any fever with acetominophen. NPO except medications.

• Do not place foley, nasogastric tube, arterial line, or central venous line unless it is absolutely necessary for patient safety.

• Do not lower blood pressure unless it is causing myocardial ischemia or exceeds 220/120 mmHg. Use labetolol iv (5–20 mg iv q 10–20 min) or, if necessary, sodium nitroprusside iv (0.5–10 μg/kg/min). Monitor with Noninvasive cuff pressures q 15 min or continuous arterial pressure monitoring. Of note, patients who have received IV rt-PA should be maintained at a BP <180/110 mmHg.

• Do not administer Heparin unless recommended by the Acute Stroke Team.

• STAT head CT/CTA and possible MRI with DWI/PWI.

• Consider bypassing CTA if renal failure, diabetes, CHF. Hold metformin 48 h after iodinated contrast.

• Check patency of 16–18 gauge forearm IV.

• Consider CXR to exclude acute CHF or aortic ­dissection if clinical suspicion.

• Check MRI exclusions (e.g., severe claustrophobia, implanted pacemaker, metal fragments, shrapnel).

• Review CT/CTA with Interventionalist and Stroke Team.

• Obtain consent for procedure and general anesthesia in writing from patient or family.

• If time permits, obtain STAT DWI MR imaging but do not significantly delay time to treatment.

13.2.6 Perithrombolysis Management

• Confirm case with Anesthesia and consider starting Heparin 2,000 U bolus and 500 U/h.

• Request OG or NG tube placement prior to thrombolytic drug infusion.

• Consider inducing moderate hypothermia (33–34°C) during the case with cooling blanket.

• Consider induced hypertension until patency restored in patients with poor collateral flow.

• Consider terminating infusion of thrombolytic by 8 h in anterior circulation stroke. Consider early angioplasty ± stenting for severe stenosis or occlusion of the extracranial carotid artery.

• To prevent or treat acute reocclusion or after angioplasty or stenting, consider IV Integrilin.

• Call for CT scan to be done postthrombolysis en route to Neuro ICU. Repeat CT 24 h later or at any point if clinical deterioration. Dual-energy head CT or brain MRI with gradient-echo may be helpful in differentiating contrast staining/extravasation from true ICH.

• Begin passive rewarming in Neuro ICU. Do not apply extra blankets or heating devices.

• If considering antiplatelet or anticoagulant agents, check fibrinogen >100 and PTT <80 s.

13.2.7 Pre- and Posttreatment Management

ICU admission for monitoring during first 24 h.

• Vital signs q 15 min for 2 h, then q 30 min for 6 h, then q 1 h for 16 h.

• Strict control of BP for 24 h per protocol.

• Neuro checks q 1 h for 24 h.

• Pulse oximeter; Oxygen canula or mask to maintain O₂ sat >95%.

• Tylenol 650 mg po/pr q 4 h prn T > 99.4; cooling blanket prn T > 102, set to avoid shivering.

• If patient has received IV rt-PA: no antiplatelet agents or anticoagulants in first 24 h.

• No foley catheter, nasogastric tube, arterial catheter or central venous catheter for 24 h, unless absolutely necessary.

• STAT Head CT for any worsening of neurologic condition.

13.2.7.1 Protocol for Blood Pressure Control After Thrombolysis

Patients will be admitted to the ICU for hemodynamic monitoring for a minimum of 24 h. A noninvasive blood pressure cuff is recommended unless sodium nitroprusside is required. BP will be strictly controlled according to the guidelines used in the NINDS trial as listed below. Clinical deterioration associated with acute reduction in blood pressure should be evaluated immediately.

Monitor arterial blood pressure during the first 24 h after starting treatment.

• Every 15 min for 2 h after starting the infusion, then

• Every 30 min for 6 h, then

• Every 60 min for 24 h after starting treatment

If systolic blood pressure is 180–230 mmHg or if ­diastolic blood pressure is 105–120 mmHg for two or more readings 5–10 min apart:

• Give intravenous labetolol 10 mg over 1–2 min. The dose may be repeated or doubled every 10–20 min up to a total dose of 150 mg.

• Monitor blood pressure every 15 min during labetolol treatment and observe for development of hypotension.

If systolic blood pressure is >230 mmHg or if diastolic blood pressure is in the range of 121–140 mmHg for two or more readings 5–10 min apart:

• Give intravenous labetolol 10 mg over 1–2 min. The dose may be repeated or doubled every 10 min up to a total dose of 150 mg.

• Monitor blood pressure every 15 min during the labetolol treatment and observe for development of hypotension.

• If no satisfactory response or bradycardia, consider nicardipine infusion (start 5 mg/h, increase 2.5 mg/h q5–15 min as needed to a maximum dosage of 15 mg/h).

If diastolic blood pressure is >140 mmHg for two or more readings 5–10 min apart:

• Infuse nicardipine.

*Continuous arterial monitoring is advised if nicardipine is used. The risk of bleeding secondary to an arterial puncture should be weighed against the possibility of missing dramatic changes in pressure during infusion.

13.2.8 Management of Symptomatic Hemorrhage After Thrombolysis

• STAT head CT, if ICH suspected.

• Consult Neurosurgery for ICH.

• Check CBC, PT, PTT, platelets, fibrinogen and D-dimer. Repeat q 2 h until bleeding is controlled.

• Give FFP 2 U every 6 h for 24 h after dose.

• Give cryoprecipitate 20 U. If fibrinogen level is <200 mg/dL at 1 h, repeat cryoprecipitate dose.

• Give platelets 4 U.

• Give protamine sulfate 1 mg/100 U heparin received in last 3 h (give initial 10 mg test dose slow IVP over 10 min and observe for anaphylaxis; if stable, give entire calculated dose slow IVP; maximum dose 100 mg).

• Institute frequent neurochecks and therapy of acutely elevated ICP, as needed.

• May give aminocaproic acid (Amicar) 5 g in 250 ml NS IV over 1 h as a last resort.