Endovascular Clot Retrieval

Airway: Own vs ETT (often RSI.
Access: Any.
Pain: Minimal. Conscious sedation can be managed with small boluses of alfentanil.
Position: Supine.
Time: 30 minutes - 4 hours.
Blood loss: Minimal
The Bottom Line: * Remote: Off-the-floor and often after hours * Proceduralists may start without anaesthesia presence * Patient position and access can be difficult * HDx stability is key: Maintain SBP 140-180mmHg

Endovascular clot retrieval is the standard of care for stroke caused by large vessel occlusions in the anterior circulation. Clot retrieval is:

• Time-critical
  Better outcomes seen earlier, with some benefit seen up to 6 hours; though this may be extended up to 24 hours in patients with favourable imaging.
• Preferable to thrombolysis when:
  • Occlusions are of large vessels
    ICA, M1, M2, basilar.
  • Early presentation
  • Significant new disability
    NIHSS >5.
  • Previously independent
• Associated with improvement in functional outcome by 20-35% at 90 days
  • NNT 5 for independence and 3 for discharge if within 5 hours of stroke onset

Surgical Stages

• Femoral access
• Navigation to clot
  Via microcatheter and guidewire.
• Removal of clot
  Removal device placed via guidewire. Options include:
  • Stents
  • Stent retriever
  • Aspiration device
  • Clot retrieval
    Placed distal to clot; balloon is withdrawn and clot removed.

Preoperative

Key decision is for conscious sedation vs. general anaesthesia * Possible trend towards benefit with sedation but not strong evidence * Decision largely dependent on patient factors: * Factors favouring conscious sedation: Conscious, cooperative, and oxygenating * Factors favouring GA: ↓ GCS, N/V, dominant hemisphere stroke, posterior circulation stroke

Assessment: * Usually time-constrained

Consultation:

Optimisation:

Premedication:

Explain/Consent:

Intraoperative

Preparation:

Induction:

Maintenance: * SBP 140-180mmHg * BSL 6-10mmol/L * CO₂35-40mmHg * Normothermia * Liase with interventionalists about points of expected pain and give analgesia accordingly

Emergence:

Postoperative

Disposition: * GA will require recovery in PACU * Sedation can be transfered to stroke unit

Referrals/Review:

Analgesia: * Avoid opioids to minimise hypercapnoea Fluids:

Thromboprophylaxis:

Specific: * Post-reperfusion BP should be maintained ⩽180/105mmHg * Risk of post-operative haemorrhagic transformation * Reperfusion * Iatrogenic injury from wires * Vasospasm

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References

1. Dinsmore J, Elwishi M, Kailainathan P. Anaesthesia for endovascular thrombectomy. BJA Education. 2018;18(10):291-299. doi:10.1016/j.bjae.2018.07.001