1. Radial Approach for CAS – tips for the novice Dr Georgi Goranov

2. CAS – an alternative to CEA?
Although meta-analysis found CEA to be superior for death, stroke and AMI for short term outcomes, CAS has become an alternative among adequately selected group of patients
To obtain results comparable to CEA an improved CAS technique is needed
CAS is considered to be highly operator dependent intervention

3. Key elements for successful CAS
Adequate patient selection
To select the most appropriate interventional access route/femoral, brachial & radial/ and to consider alternative one
Efficient distal protection
Use of specially designed carotid stents
CAS technique and operator skill and experience are of great importance for the result.

4. Interventional approach for CAS
Femoral approach is considered to be the classical access route and approach of first choise
Radial artery can be a route for the effective treatment for supraaortic pathology; it will be an essential route if a patient has significant limitation in femoral approach
CAS from the femoral approach can be problematic due to access site complications as well as technical difficulties related to peripheral vascular disease (PVD) and/or anatomical variations of the aortic arch

5. Most common major limitations of transfemoral CAS are:
Severe peripheral artery disease involving aorta and biiliac arteries or if a surgical bypass is present at this level
Extreme tortuousity of the aorta and illiac arteries
Inappropriate aortic arch anatomy and the presence of tortuous supraaortic arteries whose origin from the aortic arch makes selective catheterization by the femoral approach difficult or impossible
Severe aortic atherosclerotic disease
If tranfemoral approach is expected to have a significant risk of complications
Arm approach (brachial or radial) is an alternative in these situations

6. Advantages and Limitations of transradial approach for CAS
The best advantage of transradial approach is the greater freedom of movement and the lack of groin discomfort or lethal complications due to vascular access.
Early recovery and discharge, shorter hospitalization and less cost would be expected

7. Umhat “St.George” Interventional cardiology plovdiv
Advantages and Limitations of transradial approach for CAS
The major contraindication of radial approach for supraaortic disease is the absence of an adequate palmar arterial collateral circulation (because it will require at least 6 or 7 Fr sheaths for the endovascular treatment of carotid disease)
Allen test or baseline radial angiography may be important before the endovascular therapy to confirm the radial route
Practically, a small and tortuous radial artery at its origin can be a limitation for therapeutic rather than diagnostic procedures because of the larger diameter of the devices.

8. Contraindications for transradial CAS
Negative Allen test
Small radial artery
Tortuous radial artery
Unfavourable anatomy of the Aortic Arch and common carotid arteries
Practically, the ideal candidate for transradial CAS is a male patient with positive Allen test and large straight radial artery

10. For the carotid artery intervention, angiographic evaluation of the origin of every neck vessel, and intracranial circulation is essential
Angle of target vessel take-off is of great importance
The overall configuration of aortic arch including the origin of both carotid/vertebral arteries and subclavian arteries should be evaluated before CAS by: angiography, or non- invasively – CT or MRI angiography

11. Depending on the configuration, several catheters can be used for diagnostics
Despite the difficulty in cannulation, selective carotid angiography might be performed with Tiger, JL , mammary shape catheter from right transradial approach with high success rate
In general, Hink, Vitek, Bernstein, JB 1 catheter (Imager II, Boston Scientific) or Simmons type catheter (4 or 5 Fr) have been recommended for easy access for both carotid and vertebral arteries

12. Ipsilateral or contralateral carotid intervention
Via the right transradial approach both CCA are accessible in most of the patients
Usually, the left CCA is not accessible for intervention via the left radial approach due to very acute angle
However, in some patients the right carotid artery cannot be cannulated for the intervention via a right radial approach due to its complex orientation. In this situation, left radial approach should be attempted
In general, right radial approach will be more comfortable for left and right carotid intervention and left radial approach can be considered if the right radial approach is not possible

13. Transradial Carotid Intervention
The sequential over-the-wire approach would be the safest way
A diagnostic catheter can be advanced just proximal to the carotid bifurcation and an Amplatz Super Stiff (Boston Scientific) wire can be positioned in the external carotid artery to provide strong support for the sheath change
A guiding sheath with appropriate curve should be selected and then introduced into the target CCA over the Super Stiff wire

14. Main limitation of widespread acceptance of transradial approach was related to large, inflexible, first generation stenting systems and sheaths. However, devices have recently been well developed, down-sized, softened, and made more flexible. This technical improvement facilitated the use of transradial approach

15. Main reasons for technical cause of failure:
Unfavourable arch anatomy
Inadequate catheter support at the origin of the CCA
Use of large, inflexible stenting systems and sheaths

16. Conclusion
Transradial approach technique may be particularly useful in patients with right ICA lesions and severe PVD or unfavorable arch anatomy, and among patients with a bovine aortic arch
With increased experience of transradial coronary intervention and peripheral intervention, development of excellent embolic protection device, transradial carotid intervention can be a safe procedure with excellent acute and long-term results
For the diagnostic and therapeutic procedures involving the supraaortic vessels, the radial approach appears to be a very promising technique and might be one of best options as the future standard transcatheter intervention technique

17. PTA of LICA with implantation of carotid stent via transradial approach in acute ischaemic stroke

18. 51 year old male patient
Initial complaints (right side arm and leg paralysis, aphasia, dysarthria, left side facial palsy) – 1 hour before hospital admission
NIHSS – 20 at hospital admission
Comorbidities: Hypertension, Chronic alcohol abuse

19. CT at hospital admission: negative for intracranial haemorrhage
Duplex sonography at hospital admission: Occlusion of LICA, RICA – no pathology
Selective angiography of both carotid arteries: Acute thrombotic occlusion of LICA. RICA – no significant stenosis

21. Interventional Treatment Plan
Intra-arterial fibrinolysis: application of rt-PA into the left CCA
Thrombaspiration
Embolic protection
PTA of LICA with implantation of carotid stent

22. Application of rt-PA in left CCA
Transradial approach
5Fr diagnostic mammary shape catheter to cannulate selectively left CCA
Application of rt-PA in left CCA
Amplatz Superstiff wire positioned in left ECA
6Fr guiding sheath moved over Amplatz Superstiff wire to left CCA
Thrombaspiration
Crossing the lesion of LICA with distal embolic protection device
Implantation of Carotid Wallstent 7,0x40
Balloon post-dilation (5,0x20)

27. Conclusion
Transradial approach technique may be particularly useful in patients with right ICA lesions and severe PVD or unfavorable arch anatomy, and among patients with a bovine aortic arch
With increased experience of transradial coronary intervention and peripheral intervention, development of excellent embolic protection device, transradial carotid intervention can be a safe procedure with excellent acute and long-term results
For the diagnostic and therapeutic procedures involving the supraaortic vessels, the radial approach appears to be a very promising technique and might be one of best options as the future standard transcatheter intervention technique