ABOUT STENT RETRIEVER THROMBECTOMY ACUTE ISCHEMIC STROKE THERAPIES

Stent retriever thrombectomy is the recommended standard of care for patients suffering acute ischemic stroke (AIS), the most common type of stroke.¹ Ischemic stroke occurs when blood vessels carrying oxygen and nutrients to the brain are blocked by a clot, causing brain cells to die.

Thrombectomy – the new standard of care

The 2015 update to the AHA/ASA guidelines for early management of patients with AIS now recommends the use of endovascular treatment with stent retrievers, following IV t-PA, for eligible patients.¹

Large vessel occlusions (LVO), in particular, respond poorly to IV t-PA.^2-3

• Common LVOs:
  • 35-40% of all AIS cases. ^4-6
• Severe LVOs:
  • 4.5-fold increase in mortality⁵
  • 3-fold reduction in functional independence at 90 day follow-up (mRS 0-2)⁸

The typical AIS patient loses 2 million neurons/min in the territory at risk⁷ but ischemic penumbra can be salvaged if the vessel is quickly recanalized.⁸

Successful recanalization is associated with:

• 4-5 fold increase in the odds of good functional outcome⁸
• 4-5 fold decrease in the odds of mortality⁸

AIS Treatment options⁹

• Medical Management with IV t-PA. IV t-PA is the clot busting drug traditionally used with stroke patients. Patients must be within the time window of 0-3 hours from symptom onset per IV t-PA indications for use. There are other contraindications associated with the use of the drug as well.
• Mechanical Thrombectomy with a Stent Retriever. This minimally invasive surgical procedure uses a tiny device called a stent retriever to remove blood clots in the brain, restoring blood flow. If the patient fails IV t-PA or is ineligible for IV t-PA, they may be eligible for mechanical thrombectomy within 8 hours from symptom onset.

Thrombectomy Procedure

1. The doctor inserts a large type of IV catheter into the groin area and then passes a catheter into the blocked vessel in the brain.
2. A stent retriever, like the Solitaire™ device, is navigated within the micro catheter and positioned through the blood clot.
3. Once deployed, the clot is now embedded within the device.
4. Once entrapped within the stent retriever, the clot can now be safely removed from the body.

Be prepared to treat stroke

A good prehospital assessment and routing system is imperative to improving patient outcomes and includes:

• Identify - Protocols should cover methods of identifying stroke, treatment guidelines, transport decisions, and procedures for alerting the hospital.
• Assess – Immediately use a valid stroke scale to identify stroke patients to inform treatment and transport decisions. Common tools:
  • Cincinnati Prehospital Stroke Scale (CPSS)¹⁰
  • Los Angeles Prehospital Stroke Screen (LAPSS)¹¹
  • Los Angeles Motor Scale (LAMS)¹²
  • Rapid Arterial Occlusion Evaluations scale (RACE)¹³ which was developed to help EMS recognize a LVO
• Know Where To Go – Ambulances need to know which stroke centers in their region can perform IV t-PA and mechanical thrombectomy with a stent retriever. EMS physicians play a critical role in directing the prehospital responses to stroke.
• Notify – Early notification to the receiving hospital not only saves time but also saves brain cells that could be lost with the passing of time.¹⁴