SHA24/020004

Complications of Radial Approach & Management Dr. Mohammad Almutairi FRCPC, FACC, FSCAI President of Kuwait Medical Society Consultant Interventional Cardiologist Chairman of cardiology department Kuwait Heart Center Chest Diseases Hospital Kuwait

• Benefits documented in numerous studies in the past 10 years.

• Lower access site bleeding.

• Early ambulation  significant reduction in patient morbidity and a lower total procedure cost.

• Increasing patient preferance to transradial approach. • As a result of these benefits, there has been an increase in the use of the radial artery for interventional procedures worldwide in the past several years. • This experience has led to an understanding of the problems and complications that can result from the transradial approach.

Radial artery occlusion • Consequences usually benign. Dual blood supply provides protective mechanism. • Hand ischemia with necrosis has occurred following prolonged cannulation of the radial artery for hemodynamic monitoring in critically ill patients. This complication has not been reported yet after TRA.

ALLEN’S TEST • A pulse oximetry test is performed with the probe placed on the patient’s thumb.

• The persistence of waveform and high oximetry readings after digital occlusion of the radial artery is very strong evidence that the patient will have sufficient collateral flow to prevent hand ischemia if the radial artery should become occluded as a result of the procedure.

• Barbeau has demonstrated the reappearance of the waveform and a high oximetry reading two minutes after initial negative results. • This delayed recruitment of collaterals may be an additional explanation for the absence of hand ischemia with radial occlusion.

Several variables influence the incidence of radial artery occlusion:

• 1-Adequate anticoagulation The incidence of radial occlusion was as high as 30% in patients receiving only 1,000 units of heparin during diagnostic cath. • The incidence of radial occlusion is reduced significantly by administering at least 5,000 units of heparin during the procedure.

• 2-Catheter size Important predictor of post-procedure radial artery occlusion. • The ratio of the radial artery internal diameter to the external diameter of the arterial sheath. The incidence of occlusion was 4% in patients with a ratio of greater than 1, as compared to 13% in those with a ratio of less than 1.

• Radial procedures have traditionally been performed using 6 Fr catheters, and most patients have an internal radial artery diameter larger than the 2.52 mm external 6 Fr sheath diameter. • The incidence of radial occlusion following 6 Fr procedures is less than 5%, but the rate increases with larger sheath sizes

• Virtually all interventional procedures can now be performed through large-bore, 6 Fr guide catheters, and larger-sized catheters are rarely necessary. • For straightforward procedures, 5 Fr guide catheters may be utilized and are particularly useful in smaller women.

• The incidence of radial occlusion is significantly higher in patients with cannulation times greater than 24 hours, as compared to those under 20 hours. • Since catheters are virtually always removed at the conclusion of a catheterization or interventional procedure, the time of cannulation may not be a factor. However, prolonged postprocedure compression times, particularly with high pressure using a mechanical device, may be a factor.

3- Duration of RA compression. use sufficient pressure only to achieve hemostasis and try to remove the device as quickly as possible. A compression dressing using non-occlusive pressures can then be applied.

In summary: • post-procedure radial occlusion occurs only in a small percentage of patients and is virtually always asymptomatic because of the dual blood supply to the hand. • Patients with generalized vascular disease, diabetes mellitus, and those undergoing repeat procedures are more susceptible. • The incidence can be minimized with appropriate anticoagulation, proper sheath selection, and avoiding prolonged high-pressure compression following the procedure.

Non-occlusive radial artery injury. • Recent studies have demonstrated that permanent radial artery injury without occlusion may occur following trans-radial intervention in some patients. • Mean radial artery internal diameter as measured by ultrasound was smaller in patients undergoing repeat trans-radial interventional procedures as compared to the initial procedure, and this smaller diameter was not present on the day following the procedure, but developed during a mean follow up of 4.5 months.

• Studies demonstrated with intravascular ultrasound that this progressive narrowing is due to intimal hyperplasia, presumably induced by trauma from the cannulation sheath or catheter.

• Hyperplasia is usually segmental rather than diffuse and is not present in all patients with a previous transradial procedure.

• The ramifications of this injury are important not only in patients undergoing repeat interventional procedures, but also in patients in whom the radial artery may be used as a conduit for coronary artery bypass surgery.

Radial artery spasm.

• Much of the morbidity of the transradial procedure is related to vasospasm induced by the introduction of a sheath or catheter into the radial artery. • The vessel has a prominent medial layer that is largely dominated by alpha-1 adenoreceptor function. Thus, increased levels of circulating catecholamines are a cause of radial artery spasm. • Local anesthesia and adequate sedation to control anxiety during catheter insertion are important preventative measures.

• Nitroglycerin and verapamil are effective agents in preventing arterial spasm. • A vasodilator cocktail consisting of 3–6 mg of verapamil injected intra-arterially prior to sheath insertion is extremely effective in preventing radial artery spasm.

• Spasm distal to the access site may be a cause of access failure. Occasionally, guide wire or guide catheter induced focal spasm may occur in a tortuous segment. • Angiographic visualization of these areas is important as they generally respond to repeat verapamil or nitroglycerine administration and can be traversed with an angled hydrophilic coated guide wire. A soft-tipped coronary guide wire may also be used to cross these areas.

• Sheath-induced spasm is also minimized by the use of sheaths with hydrophilic coating. • It has documented that both patient discomfort and the force required to remove a sheath as measured by an automatic pull-back device was significantly less with hydrophilic coated sheaths as opposed to non-coated sheaths.

Local access bleeding • The most important benefit of transradial procedures is the elimination of access site bleeding complications. • The radial artery puncture site is located over bone and can easily be compressed with minimal pressure. Thus, bleeding from the radial access site can virtually always be prevented.

• Local hematomas may occur as a result of improper device application or device failure. • It is important to emphasize that compression of the radial artery both proximally and distally to the puncture site must be performed because of retrograde flow from the palmar arch collaterals.

Forearm hematoma • Bleeding may occur from a site in the radial artery remote from the access site. The most common cause is perforation of a small side branch by the guide wire in patients receiving a platelet glycoprotein IIb/IIIa inhibitor. • Avulsion of a small radial recurrent artery arising from a radial loop is another important cause of this syndrome. Hydrophilic guidewires preferentially select this small arterial remnant in patients with a radial loop and forceful advancement of the guide catheter can result in avulsion of the vessel.

Radial artery perforation

• Described in 1% of patients.

• A low threshold to perform a radial artery arteriogram when any resistance to guide wire or catheter insertion is encountered will help prevent this complication.

• Recognition of this bleeding remote from the access site is important.

• Hemostatic pressure must be applied to an area other than the access site.

• Hemostasis is usually easily accomplished by: 1- Application of an Ace bandage to the forearm.

2- A BP cuff inflated to SBP and then gradually released over a period of 1-2 hours.

3-Sealing of a perforation with a long sheath is also an option, but this is rarely necessary.

Compartment syndrome • Compartment syndrome is the most dreaded but rare complication of radial artery hemorrhage. • A large hematoma causes hand ischemia due to pressure-induced occlusion of both the radial and ulnar arteries. • Fasciotomy with hematoma evacuation must be performed as an emergency procedure to prevent chronic ischemic injury.

Access failure • Failure to cannulate the radial artery using a 20 gauge needle and a 0.025 mm straight guide wire occurs in less than 5% of patients with an experienced operator.

• This can be achieved with adequate patient sedation and local anesthesia to prevent radial artery spasm.

• The probability of failure increases as the number of unsuccessful attempts to puncture the artery increases.

• It should be emphasized that the puncture site is proximal to the styloid process of the radius bone. • The radial artery distally usually bifurcates and becomes less superficial and attempting to puncture the vessel too distally is a common cause of access failure.

• The radial loop is the most common congenital anomaly of the radial artery and may be a cause of access failure. It occurs in 1–2% of patients and may be unilateral or bilateral.

• Wide loops can occasionally be traversed with hydrophilic guidewires and 5 Fr catheters without excessive patient discomfort.

• In most cases, it is preferable to consider an alternative access site. • Radial arteries that are smaller than 2 mm in diameter are difficult to access. These are generally seen in smaller women and patients with previous radial procedures. The use of a 5 Fr guide in this situation may be an option.

Other complications

• Pseudoaneurysm formation may rarely occur at the radial artery access site. This is usually easily managed with thrombin injection and/or mechanical compression. surgery may be required.

• Radial artery avulsion due to intense spasm has been described but this complication should virtually never occur using contemporary techniques.

• Sterile abscesses rarely occur with the use of hydrophilic coated sheaths.

Conclusion • The radial artery is an excellent access site for coronary interventions.

• Although technically more challenging with a definite learning curve, there are significant advantages to this approach.

• Complications are infrequent and many are preventable with careful technique

Thank you