Radial Artery: How Many Times?
Orazio Valsecchi, Angelina Vassileva

Interventional Cath Lab, Cardiovascular Department, Ospedali Riuniti of Bergamo, Italy.

Introduction:
Transradial approach (TRA) for both diagnostic and interventional procedures is becoming common practice in many institutions. TRA is drawing much attention because of fewer bleeding and local vascular complications and significantly better postoperative quality of life to the patient1,2,21. Complications after transradial cardiac catheterization are usually less than 2%; however, the reported incidence of radial artery occlusion is 5.3% acutely and 2.8% chronically6. Furthermore, many patients for whom transradial approach is selected have significant vascular disease and require repeated percutaneous procedures through-out lifetime. It has not been previously determined very well how many times the same radial artery can be cannulated without complications3,4,5. The aim of the study was to evaluate safety, feasibility and efficacy of repeat transradial diagnostic and/or interventional procedures.
Methods:
From May 1998 to March 2009, we studied 4818 consecutive patients (75.44% male; age 64.02±11.6 Years) via radial artery by a single experienced operator. Written informed consent was obtained from all patients prior to enrolment, and the study protocol was approved by the Institutional Ethics Committee. All the patients undergoing transradial catheterization were screened for strongly palpable radial pulse. In all patients an angiography of the arteries of the upper limb at the beginning and at the end of the procedure was performed.

Radial Artery Canulation and Sheath Management
Radial artery canulation was performed with the arm positioned beside patient’s body and hyperextension of the wrist. After local anaesthesia with 1 ml of 2% xylocaine and 1 ml of sodium bicarbonate, the radial artery was punctured with a 20 gauge 1-piece metal needle and a 0.025" straight guide wire was inserted through the needle. Upon removal of the needle, a 23 cm long 6F sheath (Cordis Corporation, Miami, Florida) was placed over the guide wire. To reduce spasm and discomfort, an intra-arterial injection of a drug “cocktail” containing 200 mg of nitroglycerin, 5 mg of verapamil, 2 ml of sodium bicarbonate, and 2 ml of 2% xylocaine were given through the sheath. In all patients after sheath insertion 5000 UI of intravenous unfractioned heparin was injected to prevent sheath thrombosis. Diagnostic coronary angiography and left ventriculography was performed using 6F Sones 2 diagnostic catheter (Cordis Corporation, Miami Florida). Coronary interventional procedures were done using 5-6-or 7F guiding catheters (Medtronic,  Maple Grove, Minnesota or Boston Scientific, Maple Grove, Minnesota).The artery sheath was removed at the completion of the procedure, and haemostasis of puncture site was obtained by a selective application of gauzes pile with a double compressive bandage. Patients were then transferred to the recovery unit where the access site was closely monitored for bleeding. This compressive bandage was removed 4 hours after the procedure. Procedural success was defined as successful cardiac catheterization and/or interventional procedure by radial approach without the occurrence of significant haematoma (palpable haematoma >1x1 cm), bleeding (requiring vascular repair or compression for >2hrs), neurological deficit or loss of palpable radial pulse.

Angiography of the Upper Limb Arteries
Angiography of the upper limb arteries was performed in all patients before the procedure immediately after the sheath insertion to visualize the entire radial, ulnar and brachial arteries and to avoid the peripheral vascular complications if arterial abnormalities were present. Angiography of the upper limb arterial tree was also performed at the end of the procedure to see the integrity of the arterial structures.
Statistical analysis
Categorical data are presented as absolute values and percentages, whereas continuous data are summarized as mean value ± standard deviation (SD). Chi-square or Fisher’s exact tests was used for comparison of categorical variables as appropriate. Comparison of continuous variables was performed by means of Student’s t-test or Wilcoxon rank-sum test, as appropriate. P value < 0.05 was considered statistically significant.
Results:
Repeat transradial procedures through the same radial artery were performed in 670 patients (Table 1): twice in 514 cases, three times in 119 patients, four times in 25 patients, five times in 7 patients, six times in 3 patients, and seven times in one case. Figures 1 and 2 depicts images of the first and seventh approach in the same patient. Right radial approach was performed in 95.39% of the cases. Minimal time to redo radial approach was 70 minutes after the first procedure. Maximal period was 6 years. In 16.47% of the patients, we met high origin of radial artery; in 11.8% severe tortuosity and in 7.08% small radial artery.. 6F diagnostic and guiding catheters were used in 98.11%, 180 of the patients had a complex interventional procedure (two or tree vessel disease treatment or left main disease). 6F diagnostic and guiding catheters were used in 641 patients (98.11%), 5F in 19 patients, 7F in 8 patients. There was no significant difference in radial artery puncture success rate and vascular access time: the puncture success rate was 99.23% in the initial procedure and 98.62 % (5 puncture failure) (Figure 3) in the repeated transradial artery procedures. Vascular access time was 1.9±2.1 min at the initial procedure and 2.2±3.1 min at the repeated one (p=ns) (Fig. 4). In all patients which were male failure occurred at second radial artery puncture. In cases of failure of repeat puncture, patients were switched to contralateral radial artery. No local vascular complications such as a significant bleeding, radial artery perforation at the puncture site were meted (Fig. 5). None of the patients had ischemic symptoms in the fingers.

Table 1. Baseline Patients Characteristics

ACS= acute coronary syndrome; CABG= coronary artery by-pass grafting; PCI = Percutaneus Coronary Intervention

Figure 1: First Radial approach

Figure 2: Seventh repeated radial approach

Figure 3: Puncture success

Figure 4: Vascular access time

Figure 5: Local vascular complications and minor bleeding

Discussion:
Diagnostic imaging and coronary angioplasty via transradial approach is associated with the same success and safety as other approaches1,7-12. Transradial Approach (TRA) is more difficult to learn than transfemoral approach. There are many aspects to consider in performing transradial interventions. These include successful radial artery puncture, prevent and manage the spasm of the radial artery, negotiate the tortuosity of the subclavian arteries, choose and engage the guiding catheters, achieve adequate backup force by the guiding catheters, retrieve coronary stents in case of failure in implanting, achieve haemostasis of the radial artery etc. Despite the presence of so many obliging aspects, radial access is getting popular13,14. To achieve procedural success in repeated transradial procedures, the most critical parameter is the radial puncture.

asymptomatic loss of radial pulse during the 30-day follow-up period was 1.6%19. Nagai et al.(1999)18 and Yokoyama et al.(2000)20 have reported three factors related to radial artery occlusion: the diameter of the radial artery prior to the procedure, the ratio of the radial artery diameter to the sheath outer diameter, and diabetes.  The failure of repeat puncture may be due to thickening of the tunica intima resulting from sheath insertion injuries or because of periarterial fibrosis at the prior radial puncture site. The lumen appears to narrow gradually with repeated TRA. After a femoral approach for cardiac interventions, even if closure devices are employed, patients require post procedure bed rest for some hours (from four to twelve) which may lead to significant morbidity such as back pain, urinary retention, constipation, or deep venous thrombosis. 10 These clinical problems may be exaggerated in the elderly or in other select patient groups such as obese, arthritic, patients with chronic low back pain, and other musculoskeletal disorders.  Uncomplicated TRA procedure has many advantages like patient can move freely in the bed , have less back pain for obliged bed rest, freedom of walking, comply with personal necessities without the nurse’s help. Haemostasis time is avoided, control is easier and the engagement of a radial surveillance is quicker than a femoral one. One day after the procedure, body pain, social function, mental health, overall discomfort, back pain, ability to use the bathroom and walking ability were better in the patient with transradial procedure. There is less engagement for nurses and other department’s staff.  Radial access influences early ambulation and subsequent patient’s care, hospital length of stay, costs, and post procedural quality of life21

Figure 6: Occluded radial artery, normal interosseus and ulnar arteries

Figure 7: Retrograde approach to right subclavian artery via left subclavian artery

Conclusions: 
The advantages of transradial approach are obviusley also present in repeat TRA. For this reason it’s very important try to do repeat catheterization by radial approach. In TRA, failure of repeat puncture may be due to thickening of the tunica intima resulting from sheath insertion injuries or because of periarterial fibrosis at the prior radial puncture site. We believe that the repeated use of the same radial artery is effective in considering its high procedural success and low complication rates in the majority of patients in the hands of experienced operators.

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