How To Manage Difficult Anatomic Conditions Affecting Transradial Approach Coronary Procedures
Francesco Burzotta, Maria De Vita*, Carlo Trani
Institute of Cardiology, Catholic University of the Sacred Heart, Rome, and Italy*
Interventional Cardiology Unit, “Morgagni-Pierantoni” Hospital Forlì, Italy
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INTRODUCTION
Transradial approach (TRA) is progressively gaining acceptance as it is associated to reduction of access-site complications, earlier patient mobilization and reduction of hospital costs, compared to the transfemoral one1,2. Moreover, recent observational reports suggest that TRA selection may also result in a better clinical outcome3-5. However, a major drawback of TRA, limiting its widespread adoption, is the reported lower success rate compared to transfemoral approach (TFA) which results in a higher crossover rate to other arterial accesses1, 2. The reason for radial access failure is often related to the more complex and more frequent anatomic variants encountered in the upper limbs. Such anatomic variants should be known, promptly recognized and appropriately managed to increase the rate of successful TRA.
ANATOMIC VARIANTS AND PHYSIOPATHOLOGIC STATES WHICH MAY HINDER SUCCESSFUL TRANSRADIAL PROCEDURE
Reported technical failure for TRA procedures is between 1-5%6-8. There are several reasons leading to failure: inability to puncture the artery, radial artery spasm and anatomical variation of the brachial-radial artery axis, of the axillary-subclavian-anonymous arterial axis and of the aortic arch.
Radial Spasm
Radial artery spasm is one of the major limitations of TRA as it may occur either during puncture attempt- limiting the puncture success, during diagnostic or interventional procedure- limiting the catheters manipulation, or at the end of procedure limiting the sheath removal. Accordingly, even if radial spasm rarely leads to serious complications such as eversion atherectomy9, it is an important cause of patient discomfort and procedural failure.
Increased occurrence of radial spasm has been reported in association with small radial artery size, presence of radial artery tortuosity or anatomical abnormalities, female gender, operator inexperience, bigger sheath size, long and difficult procedures with multiple catheters exchange10-11.
Complex anatomy of the brachial-radial arterial axis
Brachial-radial arteries have a wide range of anatomical variations. Such variations of upper limb arteries have been described and classified in different autopsy studies12-13 and in echographic14,15 and angiographic15-17studies performed by groups experienced in TRA interventions. Of note, among the different anatomic variations, there is a remarkable difference regarding their relevance for TRA procedure performance. For instance, course variations of radial and brachial arteries are not evident in the angiographic studies and are not relevant for the interventional cardiologists using TRA. On the opposite, anomalies of the radial artery origin are easily detected at retrograde radial angiography and are important in the TRA setting because they are frequently associated with severe radial tortuosity, smaller radial artery and complex anastomosis between brachial or axillary arteries and the anomalous radial artery. On such bases, we recently developed a simplified “operative” classification of brachial-radial axis abnormalities which can be diagnosed by angiography and which may be relevant for TRA procedures18. Accordingly, the main variants of the brachial-radial arterial axis are:
1. Anomalous, high, origin of the radial artery 2. Severe brachial and radial artery tortuosity3. Radial and brachial artery loops4. Radial artery atherosclerosis
E mail: f.burzotta@rm.unicatt.it
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Complex anatomy of the axillary-subclavian-anonymous arterial axis
The axillary-subclavian-anonymous arterial axis may be characterized by different degrees of vessel tourtuosity and/or by atherosclerotic disease involvement.
1. Severe tortuosity of axillary-subclavian-anonymous axis
Severe subclavian and anonymous tortuosity and loops either congenital or acquired are frequently described with a reported frequency of 10% in an angiographic study on 2,341 consecutive patients19 and can be a frequent cause of TRA failure with a reported procedural failure rate of 29.4% in the angiographic study by Lo et al (2009)l17. These abnormalities are more often observed in elderly patients, in obese patients and in patients with hypertension19.
2. Atherosclerotic disease of the axillary-subclavian-anonimous arteries
The presence of an atheromatous stenosis or occlusion of the subclavian or anonymous arteries is not rare in patients undergoing coronary procedures20. Its presence should be suspected and recognized to limit potentially relevant complications during catheter advancement and manipulation. Nevertheless, most of the patients with atherosclerotic disease of the axillary-subclavian-anonymous arteries do not present tight stenoses so that catheterization is not prevented.
Difficult anatomy of the aortic arch
The aortic arch is characterized by a wide range of anatomical variations and may also be profoundly modified by aging, hypertension, atherosclerotic and connective-tissue disease. Yet, coming from the upper limbs, few aortic arch configuration have a relevant role for the success of percutaneous procedures.
1. Retro-esophageal right subclavian artery
The retro-esophageal right subclavian artery (RORSA or arteria lusoria) is the most common congenital aortic arch anomaly with a reported prevalence of 0.4 to 2%16, 21-22. This anatomic abnormality is characterized by the right subclavian artery arising from the distal and posterior margin of the horizontal part of the aortic arch at its junction with the descending aorta, less frequently from the proximal descending aorta. In the anteroposterior projection, the catheter in the arteria lusoria at its origin is more towards the left, engaging the ascending aorta with a peculiar angulation. Valsecchi et al.(2006) reported an high rate (40%) of TRA failure in case of arteria lusoria due to inability to reach the ascending aorta with the guidewire or catheter 16.
2. Aortic arch elongation
Aortic arch elongation with more distal insertion of the anonymous trunk is sometimes encountered with advanced age and hypertension. Such aortic modification is associated with an elongation of the ascending aorta and with an acute angle between ascending aorta and anonymous trunk which may render coronary cannulation extremely challenging.
3. Other anatomical abnormalities of the aortic arch
Other anatomical abnormalities of the aortic arch consisting of different and acute angulations between the anonymous trunk and the ascending aorta have been described and their diagnosis can be done by following the orientation of the wire that goes directly in the descending aorta. A particular abnormality is the posterior origin of the anonymous trunk that is often associated to extreme angulation between this artery and the ascending aorta21.
STEP-BY-STEP APPROACH IN THE IDENTIFICATION AND MANAGEMENT OF DIFFICULT ANATOMIES
Each step of TRA may be hindered by specific anatomic obstacles. Herein we discuss a step-by-step approach to manage difficulties encountered at different levels from the wrist to the coronary ostia based on the prompt recognition of the obstacle by angiography.
1. FIRST STEP: RADIAL ARTERY PUNCTURE AND WIRING
Both arterial puncture and sheath insertion are more technically challenging in the transradial approach compared to the transfemoral one, thus specific devices have been developed. Dedicated kits for transradial procedures are available according to the two main techniques of radial artery puncture: either the open-needle or the plastic-cannula technique. Open needle kits are provided with metallic wires for sheath insertion while the plastic cannula kits are usually equipped with plastic-coated hydrophilic wires. Although the latter require a specific learning curve, according to our experience they warrant a lower incidence of radial spasm following inappropriate puncture and an easier advancement in tortuous radial arteries. Transradial sheaths are available in variable length and type (i.e. with or without hydrophilic coating) but all share the concept to be
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deployed over wires thinner than the 0.035”, once commonly used for femoral sheath insertion. Most of the commercially available radial sheaths are provided with a dedicated 0.025” straight soft-tip wire. Such dedicated wires have the property to easily proceed into the radial artery minimizing the occurrence of radial artery spasm.
The occurrence of radial artery spasm represents the first cause of failure during the learning curve but its relevance decreases with advanced clinical practice. Both, increased first hit arterial sticks and posterior wall puncture avoidance (especially with open-needle) are the main causes of reduced incidence of radial spasm by expert radialists. However, radial artery spasm cannot be completely abolished and it may still hinder successful wire placement into the radial artery. As radial artery spasm, is primarily caused by arterial wall stimulation or wire-induced injury, forceful advancement of the wire into the artery should be strongly avoided, especially when the backflow is poor suggesting suboptimal arterial puncture. In such circumstances, a second arterial puncture is probably the best option in order to avoid the occurrence of diffuse, tight radial artery spasm. In case of severe radial artery spasm resulting in puncture failure, a series of options can be considered. First, if the spasm is focal with preserved pulsatility proximal or distal to it, such zone may be used for a second attempt. In our experience, we have successfully cannulated the radial artery at different levels of its course into the forearm without observing any major complication. Moreover, proximal radial artery puncture may offer the opportunity to perform radial approach even in cases of distal artery occlusion (Figure 1). In such rare cases of very proximal radial artery puncture, a higher attention should be paid to the post-procedural haemostasis as the application of haemostatic bandage is more difficult and dedicated radial haemostatic devices are unsuitable. Another option to manage unsuccessful puncture-related radial artery spasm is try to reverse spasm. To this purpose, two main strategies may be applied: administration of exogenous vasodilators (either systemically or locally) and stimulation of endogenous vasodilators release by manual compression of ulnar artery. In case of persisting failure in obtaining good backflow or in advancing the wire into the artery, if the operator has the feeling to have correctly punctured the radial artery, direct visualization of the artery by angiography, performed by directly injecting contrast through the needle or (more easily) through the plastic cannula, is helpful (Figure 2 A). Distal radial angiography is extremely helpful in disclosing wrong position of the needle since contrast media extravasations may be recognized, thus preventing radial artery injury related to wrong sheath insertion. On the other hand, if the needle is correctly positioned into the radial artery, angiography may help to clarify the obstacle preventing wire advancement into the artery. Tortuosities, spasm or atherosclerotic stenoses of the radial artery are easily recognized and wire advancement guided by angiography may be often safely carried out beyond the obstacle. Sometimes, when extremely complex anatomy of the forearm is faced, a 0.014” coronary guidewire
may be useful to cross the obstacle and achieve sheath placement (Figure 2). However, when a coronary wire is used, there are some points that need to be kept in mind to facilitate sheath advancement through the cutaneous and subcutaneous tissues. It is advisable to advance the wire tip distally into the brachial or, better, the subclavian artery, to select extrasupport guidewires, to use wet hydrophilic sheaths and to check under fluoroscopy the advancement of the radial sheath into the distal artery. If any resistance is encountered, the sheath’s dilator may be inserted first into the artery and used to exchange the 0.014” coronary wire for the more appropriate 0.025” sheath’s wire to facilitate sheath insertion.
Figure 1. Left radial approach with sheath insertion in the mid radial artery in a patient with occluded distal radial (black arrow).
Figure 2. Retrograde radial angiography from the plastic cannula in a patient with multiple radial spasms and tortuosity (panel A) which prevented advancement of the 0.025” sheath’s wire. Under road mapping (panel B and C) a 0.014” extra-support coronary guidewire is advanced (black arrow) and used to successfully place a 6F hydrophilic sheath into the artery (panel D).
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2. SECOND STEP: WIRE ADVANCEMENT IN THE PROXIMAL RADIAL ARTERY
Once the sheath has been introduced into the radial artery for at least few centimeters, retrograde radial angiography can be easily performed in case of difficulties in advancing the wire. Valsecchi et al.(2006) routinely performed retrograde angiography after complete or partial sheath insertion in unselected patients providing a comprehensive description of the arm anatomy and its anatomic variants16. Accordingly, we recommend to perform retrograde radial angiography anytime the wire advancement is not easy. As previously discussed, arm’s arteries abnormalities are common and their prompt recognition is necessary for quick, safe and successful TRA. Blind advancement against resistance of wires may result, especially when abnormal radial anatomies are present, in painful arterial spasms or even in arterial wall dissections and perforations. Retrograde radial arteriography should be performed with appropriate angulations to visualize the arterial course. Usually, the antero-posterior view with arm extra-rotation is sufficient to have good separation of the radial and ulnar bones. Oblique views are sometime required to better visualize complex radial anatomies or to have correct visualization of the arteries when the patient’s arm cannot be extra-rotated (i.e. in case of reduced arm mobility or when dedicated arm set-ups are used). Few milliliters of contrast media, possibly diluted with saline solution to minimize patient’s discomfort, allow high quality radial angiography.
Once the arm anatomy has been disclosed, the appropriate strategy to overcome the specific obstacle can be applied. In case of radial spasm, intra-arterial administration of vasodilator drugs usually solves the problem. If spasm is associated with tortuosity, hydrophilic 0.035” wires are advisable to avoid spasm recurrence induced by wire advancement. When anatomic variants of the radial artery occur, wire advancement should be performed under road-mapping guidance (Figure 2 B, C) or, alternatively, at least with the help of previous angiography stored on the reference screen. Regardless the type of angiographic guidance, wires should be advanced under fluoroscopy and re-angiography performed to visualize more proximal arterial segments not previously visualized.
Figure 3. Retrograde radial angiography from sheath showing a radial with high origin from the axillary artery with extremely tortuous course (panel A and B). The hydrophilic wire advancement is supported and directed using a 4F JR4 diagnostic catheter according to a “catheter-oriented wire-advancement” technique finally reaching the axillary artery (panel C and D).
spite of catheter guidance. In these rare circumstances, we recommend to use a 0.014” coronary guidewire. We usually select the Choice PT extrasupport (Boston Scientific) as it both easily navigates through tortuosities, due to the hydrophilic tip, and provides good support for advancement of the diagnostic catheter due to its rigid shaft. Once the coronary wire has crossed the tortuosities, the 4F catheter can be slowly advanced over its support. As soon as proximal arm arteries are reached by the catheter, the coronary wire is removed and exchanged with a 0.035” wire to appropriately support further catheter advancement in larger vessels. In rare circumstances, a single 0.014” wire does not provide enough support for catheter advancement thus a second wire may be required and advanced according to the previously described “buddy wire” technique (Figure 4)23.
The most challenging anatomic condition is probably represented by radial and brachial loops. To successfully carry-on a transradial procedure in patients with this anatomic variant, the loop should be first crossed and then straightened (Figure 5). The first task is usually obtained after the simple passage of a 0.035” wire or (less likely) a 0.014” wire. Usually, the loop is maintained during the wire’s soft tip advancement, but it straightens after crossing with the stiffer shaft of the
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Figure 4. Retrograde radial angiography from the sheath just partially inserted in the distal radial artery showing a radial severe tortuosity with “Z-shape” (panel A). The tortuosity is negotiated by a 0.014” extra-support coronary guidewire (panel B) which is not able to straighten the vessel. Thus, according to a buddy wire technique a 0.035” hydrophilic wire is advanced in parallel (panel C) allowing for vessel strengthening and successful placement a long (25 cm) hydrophilic sheath in to the radial and brachial artery (panel D).
Figure 5. Retrograde radial angiography from sheath showing a radial loop in the mid portion of the vessel (panel A). The loop is negotiated by a 0.035” hydrophilic wire (panel B) which is able to straighten the vessel with its stiffer shaft (panel C).
Figure 6. Ulnar access in a patient with previous failure on radial loop. During the first procedure with transradial approach it was not possible to straighten the radial loop so that crossover was necessary (panel A, B). However, as retrograde angiography showed a straight ulnar artery (panel A) when the patient came back for a new procedure, after reverse Allen test confirming integrity of the radial artery, ulnar access was successfully selected as forearm approach (panel C)
wire (Figure 5). Sometimes, when the loop is very large, the wire shaft cannot be advanced through it. In such cases, a support catheter can be advanced into the loop over the wire to increase its pushability. Once the wire has crossed with its rigid shaft, the loop is usually straightened by the wire itself. If this does not help, the support catheter should be advanced through the loop and then the catheter-wire system should be rotated with a gentle pullback to straighten the loop. According to our experience, such maneuvers are able to safely and successfully negotiate 60-70% of the radial loops. However, there are cases in which the loop cannot be straightened or in which straightening is associated with intolerable arm pain. In these circumstances, the crossover to another access can not be avoided. It should be noted that the identification of a radial loop impossible to straighten in a previous catheterization represent a good indication for ulnar artery access selection in the case of need of a novel procedure, provided that the radial integrity is preserved (Figure 6).
Finally, loops of the brachial artery are less frequently encountered. As the brachial is bigger than the radial artery and less prone to develop spasm, these loops are usually crossed and straightened by a 0.035” wire (supported by a 4 F, JR4 catheter if needed). However, as a brachial artery injury may result in hand or even arm ischemia, it is mandatory to keep maximal attention during all phases of loop negotiation.
3. THIRD STEP: WIRE ADVANCEMENT IN THE AXILLARY-SUBCLAVIAN-ANONYMOUS AXIS TO REACH THE ASCENDING AORTA
The axillary-subclavian-anonymous axis often presents some tortuosity and, especially in patients with ischemic heart disease, may be the location of atherosclerotic plaques. In majority of the cases, such tortuosities and parietal irregularities do not offer a major obstacle to the advancement of wire and catheters in the ascending aorta. However, when the wire advancement is difficult, we recommend performing an angiography to recognize the obstacle. Angiography should be performed with the catheter placed in the proximity of the possible obstacle as blood washing may lead to false diagnosis of arterial obstruction. When the obstacle is caused by severe tortuosity, a diagnostic catheter may be used to support the advancement of a hydrophilic 0.035” wire which usually crosses the bends and reaches the aorta straightening the vessel (Figure 7). Sometimes, due to tortuosities, the wire goes into the descending instead of the ascending aorta. In these cases, slight retrieval of the wire and re-advancement under patient’s deep breathing is usually successful. If the wire keeps going into the descending aorta, a diagnostic catheter can be advanced into the aortic arch and the tip rotated to redirect the wire towards the ascending aorta. These maneuvers are also helpful to reach the ascending aorta in patients with aortic arch anatomic variations including the retro-esophageal right subclavian artery (RORSA or arteria lusoria) (Figure 8).
Occasionally, wire advancement is hindered by an atherosclerotic lesion of the anonymous or subclavian artery. Although moderate lesions can be safely crossed with a 0.035” hydrophilic wire supported by a JR4 diagnostic catheter, the residual luminal diameter and the lesion site, mainly the proximity to the vertebral or right internal carotid arteries take off, must be carefully evaluated before attempting to advance the wire or the catheter beyond the stenosis.
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Figure 7. Retrograde angiography from the a 6F JR diagnostic catheter showing severe tortuosity of subclavian-anonymous arterial axis (panel A). The diagnostic catheter is used to direct ad support advancement of a 0.035” hydrophilic wire (panel B) which is able to straighten the vessel when its stiffer shaft is further advanced in the ascending aorta (panel C). In such cases, rotation of the catheter may be difficult or impossible without the wire inside. Thus the right coronary is cannulated with the 0.035” wire inside the catheter (arrow, panel D). Moreover, the Judkins curve was not able to cross the straightened tortuousity. Thus, an extra back-up guiding catheter is successfully advanced (panel E) and left coronary angiography is performed with the 0.035” wire kept inside (arrow, panel F).
Figure 8. Right transradial subtraction aortography in a patient with a retro-esophageal right subclavian artery (RORSA or arteria lusoria
4. FOURTH STEP: CORONARY ARTERY CANNULATION
Once the wire and the catheter have reached the ascending aorta, the achievement of transradial coronary angiography or intervention are highly probable but still not warranted. Indeed, there are cases in which the catheter exchange or catheter manipulation to cannulate the coronary ostia are extremely difficult. This usually happens when the previous three steps
have been technically challenging. Indeed, arterial spasm often develops in case of severe tortuosities limiting catheter advancement and manipulations and is common in small anomalous radial arteries and in brachio-cefalic axis with anomalous course or take off. In such extreme conditions, when ascending aorta negotiation has been successful, it is mandatory to pay maximal attention in maintaining the position of the wire. In case of need to exchange catheter, we recommend to use a 300 cm exchange wire or the “jet exchange” maneuver.
When radial spasm develops, vasodilators should be administered through the sheath. If this does not help, catheters smaller than those previously used can be selected to complete the procedure (i.e. exchange 5F for 6F or 4F for 5F). Particular care must be paid when resistance is encountered during guiding catheters advancement. Since the gap between the wire and the lumen is larger than with the diagnostic catheters, catheter tip may result more traumatic for a small tortuous and spastic radial artery. In these circumstances, selecting smaller guiding catheter or reducing this gap by using a “telescopic” technique (i.e. a 4 F long diagnostic catheter inside the 6 F guiding catheter) is advisable.
When reduced catheter manipulation is caused by tortuosity of the brachio-cefalic axis any attempt to force distal catheter movements may induce troublesome catheter kinking. whenever, the rotations of the proximal catheter are not followed by the catheter tip movements, we suggest to readvance the 0.035” wire into the catheter and manipulate it keeping the wire inside (Figure 7). Since contrast injection during coronary cannulation is impossible through a diagnostic catheter housing a 0.035” wire, in difficult anatomies, we exchange the diagnostic catheter for a guiding catheter attached to a Y connector to allow angiography with the wire loaded (Figure 7). Sometimes the brachio-cefalic axis is so extremely tortuous that the advancement of specific catheters is impossible. This is usually caused by arterial bends similar to catheter’s curvatures making the distal catheter seating in the artery and loosing pushability. This typically happens with the left Judkins or Amplatz double bended curves while with the single bended extra-back-up curves it is less likely (Figure 7). These catheters should be selected to cannulate the left coronary artery when left Judkins or Amplatz fail to reach the ascending aorta.
Finally, when the tortuosities require 0.035” wire support during catheter positioning, to increase the stability of the catheter for coronary interventions, it is advisable to advance into the target vessel the 0.014” guidewire, and additional “buddy wires” if needed24, before removing the angiographic wire (Figure 9).
CONCLUSIONS
The progressively increasing success rate achievable during the learning phase of TRA is not only related to a technical improvement in radial artery puncture but also to the knowledge of the possible anatomic obstacles and the appropriate techniques to overcome them. We propose a step-by-step approach based on the prompt problem recognition by retrograde arterial angiography and on the application of a series of tailored maneuvers useful to overcome the anatomic obstacles hindering successful transradial coronary procedures.
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Figure 9: Right transradial percutaneous coronary intervention on left anterior descending artery in a patient with extreme subclavian-anonymous arterial axis tortuosity (panel A). An hydrophilic 0.035” wire is advance into the toprtuosity and provides support for the advancement of a left extra-back up guiding catheter (panel B and C). However, manipulation of the guiding catheter is limited by the tortuosities so that cannulation is achieved maintaining the 0.035” wire loaded in the catheter (white arrow, panel D). As soon as the left main is cannulated, a 0.014” guidewire is placed in the circumflex artery (black arrow, panel D and E) to stabilize the catheter and to facilitate safe lesion crossing on the target left anterior descending artery. Then the two 0.014” wires are placed in the left anterior descending artery and in its diagonal branch, so that direct stenting may be performed after removal of the 0.035” wire (panel E) achieving optimal angiographic result (panel F).
REFERENCES
1. Agostoni P, Biondi-Zoccai GG, de Benedictis ML, Rigattieri S, Turri M, Anselmi M, et al. Radial versus femoral approach for percutaneous coronary diagnostic and interventional procedures; Systematic overview and meta-analysis of randomized trials. J Am Coll Cardiol. 2004;44:349-356.
2. Jolly SS, Amlani S, Hamon M, Yusuf S, Mehta SR. Radial versus femoral access for coronary angiography or intervention and the impact on major bleeding and ischemic events: a systematic review and meta-analysis of randomized trials. Am Heart J. 2009;157:132-140.
3. Chase AJ, Fretz EB, Warburton WP, Klinke WP, Carere RG, Pi D, et al. Association of the arterial access site at angioplasty with transfusion and mortality: the M.O.R.T.A.L study (Mortality benefit Of Reduced Transfusion after percutaneous coronary intervention via the Arm or Leg). Heart. 2008;94:1019-1025.
4. Pristipino C, Trani C, Nazzaro MS, Berni A, Patti G, Patrizi R, et al. Prospective REgistry of Vascular Access in Interventions in Lazio Region Study Group. Major improvement of percutaneous cardiovascular procedure outcomes with radial artery catheterisation: results from the PREVAIL study. Heart. 2009;95:476-482.
5. Sciahbasi A, Pristipino C, Ambrosio G, Sperduti I, Scabbia EV, Greco C, et al. Arterial access-site-related outcomes of patients undergoing invasive coronary procedures for acute coronary syndromes (from the ComPaRison of Early Invasive and Conservative Treatment in Patients With Non-ST-ElevatiOn Acute Coronary Syndromes [PRESTO-ACS] Vascular Substudy). Am J Cardiol. 2009;103:796-800.
6. Kiemeneij F, Laarman GJ, Odekerken D, Slagboom T, van der Wieken R. A randomized comparison of percutaneous transluminal coronary angioplasty by the radial, brachial and femoral approaches: the access study. J Am Coll Cardiol. 1997; 29(6):1269-1275.
7. Ludman PF, Stephens NG, Harcombe A, Lowe MD, Shapiro LM, Schofield PM, et al. Radial versus femoral approach for diagnostic coronary angiography in stable angina pectoris. Am J Cardiol. 1997; 79(9):1239-1241.
8. Hildick-Smith DJ, Ludman PF, Lowe MD, Stephens NG, Harcombe AA, Walsh JT, et al. Comparison of radial versus brachial approaches for diagnostic coronary angiography when the femoral approach is contraindicated. Am J Cardiol. 1998; 81(6):770-772.
9. Dieter RS, Akef A, Wolff M. Eversion endarterectomy complicating radial artery access for left heart catheterization. Catheter Cardiovasc Interv. 2003;58:478-480.
10. Ruiz-Salmerón RJ, Mora R, Vélez-Gimón M, Ortiz J, Fernández C, Vidal B et al. Radial artery spasm in transradial cardiac catheterization. Assessment of factors related to its occurrence, and of its consequences during follow-up. Rev Esp Cardiol. 2005;58:504-511.
11. Louvard Y, Pezzano M, Scheers L, Koukoui F, Marien C, Benaim R, et al.
Coronary angiography by a radial artery approach: feasibility, learning curve. One operator's experience. Arch Mal Coeur Vaiss. 1998;91:209-215.
12. Mc Cormack LJ, Cauldwell EW, Anson BJ. Brachial and antebrachial arterial patterns; a study of 750 extremities. Surg Gynecol Obstet. 1953; 96(1):43-54.
13. Rodríguez-Niedenführ M, Vázquez T, Nearn L, Ferreira B, Parkin I, Sañudo JR. Variations of the arterial pattern in the upper limb revisited: a morphological and statistical study, with a review of the literature. J Anat. 2001; 199(Pt 5):547-566.
14. Yokoyama N, Takeshita S, Ochiai M, Koyama Y, Hoshino S, Isshiki T, et al. Anatomic variations of the radial artery in patients undergoing transradial coronary intervention. Catheter Cardiovasc Interv. 2000; 49(4):357-362.
15. Yoo BS, Yoon J, Ko JY, Kim JY, Lee SH, Hwang SO, et al. Anatomical consideration of the radial artery for transradial coronary procedures: arterial diameter, branching anomaly and vessel tortuosity. Int J Cardiol. 2005; 101(3):421-427.
16. Valsecchi O, Vassileva A, Musumeci G, Rossini R, Tespili M, Guagliumi G, et al. Failure of transradial approach during coronary interventions: anatomic considerations. Catheter Cardiovasc Interv. 2006;67:870-878.
17. Lo TS, Nolan J, Fountzopoulos E, Behan M, Butler R, Hetherington SL, et al. Radial artery anomaly and its influence on transradial coronary procedural outcome. Heart. 2009; 95(5):410-415.
18. Burzotta F, Trani C, De Vita M, Crea F. A new operative classification of anatomic variants and physiopatologic states relevant for transradial cardiovascular procedures. Int.J.Cardiol 2009 (in press).
19. Cha KS, Kim MH, Kim HJ. Prevalence and clinical predictors of severe tortuosity of right subclavian artery in patients undergoing transradial coronary angiography. Am J Cardiol. 2003;92(10):1220-1222.
20. Rigatelli G, Rigatelli G. Screening angiography of supraaortic vessels performed by invasive cardiologists at the time of cardiac catheterization: indications and results. Int J Cardiovasc Imaging. 2005;21(2-3):179-183.
21. Hamon M, Mc Fadden E. Transradial approach for cardiovascular interventions. ESM Edition 2003. Chapter 16.
22. Abhaichand RK, Louvard Y, Gobeil JF, Loubeyre C, Lefèvre T, Morice MC. The problem of arteria lusoria in right transradial coronary angiography and angioplasty. Catheter Cardiovasc Interv 2001; 54:196-201.
23. Burzotta F, Trani C, Mazzari MA, Mongiardo R, Rebuzzi AG, Buffon A, et al. Use of a second buddy wire during percutaneous coronary interventions: a simple solution for some challenging situations. J Invasive Cardiol. 2005;17:171-174.
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