Failed thrombectomy - SLICE Worldwide 2022

Failed thrombectomy – initially typical looking M1 occlusion with unproductive passes 2021 statement + 2022 update

The technical success of endovascular stroke therapy is one of the most important modifiable predictors of therapy benefit in patients presenting with large-vessel-occlusion acute ischemic stroke. While unsuccessful reperfusion (≤TICI 2a) often results from incomplete retrieval due to distal embolization and/or clot fragmentation (TICI 2a), in some patients, no reperfusion (Thrombolysis In Cerebral Infarction score = TICI 0/1) can be achieved and is called reperfusion failure. This applies to 5%–10% of patients with acute ischemic stroke with an intention to treat with mechanical thrombectomy[1].

Proposed approach

Since the beginning of the procedure, you may introduce Nimodipine or Milrinone i.a. in order to relax the vessel and decrease the friction between the vessel wall and later on used devices.

1. First line treatment: aspiration 
   ➤ 2 attempts before changing the technique*Alternative treatment: maximalist approach with stent-retriever (+by-pass test)
   
   
2. Alternative treatment: maximalist approach with stent-retriever (+by-pass test)
   ➤ 2 attempts before changing the technique*

or

1. First line treatment: maximalist approach (aspiration catheter+stent retriever+/-BCG)
   ➤  2 attempts before changing the technique* (+by-pass test in second attempt; in case of failure after first pass you may consider go to the second MCA branch for the second pass)
2. Alternative treatment: direct aspiration
   ➤ 2 attempts before changing the technique*

* If you are convinced that taken strategy will fail also at second attempt, you may reduce the number of passes to only one attempt. As for the aspiration technique, you can also try changing the type of aspiration catheter and the way the catheter adheres to the clot.

1. Bailout strategy* in bifurcation M1/M2 occlusion: double stent-retrievers
   or
2. Bailout strategy* in trunk M1 occlusion: pinching with regular stent-retriever or with Nimbus (in trunk occlusion with suspicion of white clot)
   ➤ up to 2 attempts

* If the procedure takes long or you have already performed many attempts or if you have strong suspicion of underlying intracranial stenosis, it is recommended to load the patient with antithrombotic drug i.v. such as Tirofiban or Integrilin or Cangrelor. This will secure endothelial damage after many passes and stabilize the lesion as well as maintain vessel patency after PTA/stent placement.

You may implement part of the drug through the opened stent-retriever i.a. – this may improve resolution of the thrombus, however be aware of possible increase of the rate of intracranial hemorrhage[2].

Dosage:

Tirofiban:

• Cardiological dose: 25 mcg/kg i.v. loading dose infused within 5 min, THEN 0.15 mcg/kg/min i.v. continuous infusion

Integrilin:

• Cardiological dose: 180 mcg/kg i.v. bolus over 1-2 min, THEN 2 mcg/kg/min i.v. continuous infusion
  ➤ you may keep the full dose or give an half dose
  ➤  you may skip the continuous infusion and keep only the loading dose/bolus

Cangrelor:

• Montpellier team dose: 5-7.5 mcg/kg i.v. bolus, THEN 1 mcg/kg/min i.v. continuous infusion

1. By-pass test positive: rescue stenting with laser-cut oversized stent or balloon-mounted coronary stent
   
2. By-pass test negative: pre-stenting PTA or rescue stenting with balloon-mounted coronary stent
   
   Reasons for reperfusion failure in stent-retriever thrombectomy are heterogeneous. Systematic reporting standards of reasons may help to further estimate relative frequencies and thereby guide priorities for technical development and scientific effort [1]
   
   

Literature

1. Kaesmacher, Johannes, et al. "Reasons for reperfusion failures in stent-retriever-based thrombectomy: registry analysis and proposal of a classification system." American Journal of Neuroradiology 39.10 (2018): 1848-1853.
2. Yang, Jianhong, et al. "Intraarterial versus intravenous tirofiban as an adjunct to endovascular thrombectomy for acute ischemic stroke." Stroke 51.10 (2020): 2925-2933.