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

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

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.

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

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

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

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.

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

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

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

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

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

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

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

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

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

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

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

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

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)

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