Chronic Ischemia - Ep.2/2 - SLICE WorldWide 2022

Chronic total carotid occlusion – Here is a short recap of how to do it

Introduction

Endovascular treatment for chronic carotid total occlusion is still a debatable procedure with uncertain medical benefits. However, once a decision for endovascular reconstruction is considered, several key-procedural steps are necessary to ensure the procedure will not lead to massive unwanted cerebral embolism and complication rates are kept reasonably low.

A stepwise approach to endovascular reconstruction of a chronically occluded carotid artery [1]. It is recommended that the operator splits the procedure into several steps that a clearly demarcated and clearly defined. Splitting the procedure into these critical steps is a reasonable way to ensure safety and efficacy and to facilitate concentration during a three-four hour procedure.

1. The intimal dissection phase

- Echo-guided femoral puncture to ensure optimal puncture site and reduce puncture-related complications

- 9-Fr Balloon-guide catheter in the CCA – to ensure optimal continuous flow control during the procedure

- Ensure optimal control of the distal target zone (either through external collaterals or another diagnostic catheter placed in the contralateral ICA or a vertebral artery)

- 5-Fr 125 Vertebral Catheter to ensure support during the dissection phase

- 0.014’’ microguidewire and microcatheter to perform dissection

- Implant the 5-Fr in the carotid stump and start dissection anterogradely 

2. Catheterization of the ICA lumen

-  Blindly progress through the supposed ICA lumen and try to reach a free movement of the guidewire signifying the “true” lumen as early as possible

- Try not to knuckle the guidewire ensure gently torquing maneuvers as not to extend the wall hematoma

- Verification if the true lumen is reached should be based on gentle aspirations in the 3 ml syringe

- The 5-Fr can be advanced in the cervical carotid to gain support

- The re-entry phase is the most dangerous, and re-entry should not cut off or dissect collateral flow. Slowly torque and advance the guide wire in the distal stump. It is common to use more than one guidewire. Sometimes you need to reverse the guidewire and gently push using the microcatheter, but more than everything, patience is key.

- Before reconstruction begins, if the collateral circulation is not affected, the procedure can be abandoned without incurring significant complications.

3. Anterograde reconstruction

- Once the true lumen is gained, a 3-meter J-shaped exchange guidewire is put in the MCA.

- Start by performing angioplasties followed by self-expandable stent reconstructions of the cervical carotid artery. Everything should be performed under flow arrest, and aspiration should be performed each time before de-inflating the balloon-guide.

- Once the first cervical stent is implanted, advance your balloon-guide catheter in the cervical reconstructed carotid. The petro-cavernous part should still be occluded as it was not angioplasties. Cut the flow in the balloon-guide and open the hub so blood-flows on the table. Theoretically, this will serve as a control for when the carotid is entirely patent, as blood will start flowing on the table only when you recanalize the petrous-cavernous segment. 

4. Retrograde reconstruction

- Perform angioplasties of the distal petro-cavernous ICA

- Use chrome cobalt flow-diverter stents to reconstruct the ICA retrogradely. Coronary stents may also be used, but they pose more problems with tortuous segments and are more challenging to cross.

- Petrous overlap can be performed by flow-diverter or self-expandable carotid stents, ensuring good inter-stent apposition and overlap.

- Post-angioplasty, the full metal jacket, especially at the overlap zones.

- Ensure optimal flow arrest and flow-reversal during the whole the procedure

Conclusion

To obtain reproducible and good results with endovascular carotid recanalization, some key steps have to be taken into account. Furthermore, groups performing these techniques should publish a detailed account of how the procedure was performed as peri-procedural complications are strongly related to operator technique.

Further reading

Radu RA, Cagnazzo F, Derraz I, et al. Modern endovascular management of chronic total carotid artery occlusion: technical results and procedural challenges. J Neurointerv Surg 2022;:neurintsurg-2022-019219. doi:10.1136/jnis-2022-019219