Replay Day 2 - Slice WW 2021 - Best technique 1              

Best technique for basilar artery thrombectomy in 2021

Live demonstration of the use of equipment and techniques on silicone models filmed in high resolution. These practical highlights present the different techniques from an educational perspective.

Thrombectomy of long clot involving BA-P1 segment with unknown site of the occlusion performed simultaneously in two angio-suites. The aim is to check whether the selected segment (right vs. left P1) is important for the effectiveness of thrombectomy.

Case: Long clot involving BA-P1 segment (unknown site) – with left P1 approach

Preferred technique of Pr. Jan Gralla: Femoral access 6F via left VA (if the artery is big, 7F or 8F and guide catheter would be an option) + distal aspiration catheter + stent-retriever + aspiration by syringe

Remark: In basilar tip occlusion etiology is usually thromboembolic and the clot may extend to the bifurcation and involve both P1 arteries – the P1 which is occluded in longer segment would be the target.

Procedure step by step in angio-suite :

In use: Infinity 6F – VECTA 74 – TRAK 21 – Synchro – Trevo 4 x 35 mm

- go with your aspiration catheter + microcatheter + microwire to the selected vertebral artery 

- pass the thrombus with the microwire and the microcatheter 

Remark: pay attention to:

• not catheterize SCA instead of PCA – observe the course of the wire whether it looks supratentorial or infratentorial; you can also perform a distal injection from microcatheter 
• not catheterize perforators outgoing from the tip of BA – your wire should never go straight up (that is where the perforators are located)

- Do not worry if your aspiration catheter does not go up to the front of the thrombus, once you will have the SR in place, it will work as an anchor so you would be able to pull the aspiration catheter up

- Perform the distal microangiography to confirm its proper position prior stent-retriever deployment (at least if it is the first pass)

- Deploy the SR: 2/3 distally to the thrombus, 1/3 within and proximally 

remark:  do not go too distally with SR because, further, the course of the artery is tortuous

• (in presented case) PINCHING technique (take back 2/3 of SR into the microcatheter and leave 1/3 of SR outside) + double aspiration on aspiration catheter and on sheath

- Evaluate if everything is open

-If there is a clot remnant, repeat the procedure

• (in presented case) 2nd pass – SOLUMBRA with aspiration catheter left in origin of right PCA in order to protect the left PCA (the reopened one) 
• (in presented case) 3rd pass – ASPIRATION only in remnant occluded right SCA

Case: Long clot involving BA-P1 segment (unknown site) – with right P1 approach 

Preferred technique of Pr. Tommy Andersson: 6F via left VA (the larger one; if it is large enough, BCG has application) + distal aspiration catheter + stent-retriever + aspiration by syringe

Remark: if you have angio-CT, try to find out which P1 is occluded by a clot; if you do not have CT prior thrombectomy, you can go to the easier one for the catheterization 

Procedure step by step in angio-suite:

In use: 6F Infinity – Catalyst 6F – Headway 21 Long 165  – Tracess – Embotrap 4 x 37 mm

- Go with your aspiration catheter + microcatheter + microwire to the selected vertebral artery 

- Advance your microwire and microcatheter tip-to-tip and then, when you are in front of the thrombus, you can:

• go with your wire to P1 segment with the J shape 
• try to push the microcatheter alone to P1 while maintaining the position of microwire 

remark: pay attention to the perforators! – this technique may be more applicable in anterior circulation (less perforators)

- Deploy the stent-retriever in the desired position 

• you can remove the microcatheter and leave only aspiration catheter + stent-retriever, or keep it in place and re-sheath a little bit the stent-retriever
• (in presented case) PINCHING technique + double aspiration on aspiration catheter and on sheath

- Evaluate if everything is open (in presented case full recanalization after one pass)

Final remark: 

With slight differences, the technique was the same, what differed was thrombectomy in the corresponding segment with the clot position (BA-right P1 PCA)  – by Pr. Tommy Andersson (right P1) vs. discordant segment – by Pr. Jan Gralla (left P1). As demonstrated, the choice of the site of stent deployment is important for the effectiveness of the thrombectomy and should be the same as the thrombus location.