Transulnar Approach: the Rationale from the Radialist’s View
Pedro Beraldo de Andrade, Marden André Tebet, Mônica Vieira Athanazio de Andrade, Luiz Alberto Piva e Mattos, André Labrunie.
Santa Casa de Marília, Marília, SP, Brazil.

Introduction:
            Evidences showing a narrow relationship between the occurrence of bleeding and the increased risk of major adverse events, including death, myocardial infarction (MI) and stroke are growing¹. Notably, vascular complications related to the puncture site are among the principal causes of bleeding in patients submitted to invasive coronary procedures, especially in the validity of acute coronary syndromes, where aggressive antithrombotic therapy is frequently used².
            Recent meta-analysis demonstrated that the use of the radial access promoted a significant reduction of 73% in the major bleeding rate, when compared to the femoral access and a trend towards a reduction of 30% in the occurrence of major cardiovascular events, representing an important intervention target in the prevention of this undesirable complication³.
            However, there is a failure rate of approximately 5% to 15% with radial access, mainly due to anomalies in the Allen test, significant anatomical variations of the radial artery, such as small-vessel caliber, tortuosities, stenosis, aberrant origin, hypoplasia, or vessel spasm4. Aiming to provide the same benefits of radial access, and faced with the impossibility of its use, ulnar access presents itself as an attractive alternative approach5.
            The purpose of this study was to evaluate the safety and effectiveness of the ulnar access in the performance of diagnostic and therapeutic coronary procedures, in a non-selected population, after failed attempt in obtaining radial access.

Methods:
            Patients who underwent coronary procedures via ulnar access, due to failure in obtaining radial access, or in the presence of a more superficial and more prominent ulnar pulse, were included in a prospective registry of safety and effectiveness. The modified Allen test was not performed in routine. Through hyperextension of the wrist and infiltration of 1 to 2 ml of xylocaine at 2%, the ulnar artery was punctured at 1 to 3 cm proximal to the pisiform bone, using a 20 G JelcoÔ needle-mounted intravenous catheter (Johnson & Johnson) and the Seldinger technique. After the puncture, a 0.021-inch guide-wire (Terumo Corporation, Tokyo, Japan) was introduced, followed by a small cutaneous incision with a No.11 surgical blade and the insertion of a 5Fr or 6Fr short introducer (10 cm) (Terumo Corporation, Tokyo, Japan). A solution containing 5000 IU of heparin sulfate and 10 mg of isosorbide mononitrate was administered through the extension of the introducer. After finishing the procedure, the introducer was immediately removed and hemostasis was achieved with compressive dressing. Clinical examination of the puncture site and evaluation of the ulnar pulse were performed at the moment of hospital discharge, three hours after completion of coronary angiographies and the morning following percutaneous coronary intervention (PCI).

The effectiveness of the technique was evaluated by the success rate of the procedure, defined as completion of coronary angiography and left ventriculography with adequate coronary opacification, and PCI obtaining residual lesion inferior to 30%, with no need of changing the access route. The procedure and fluoroscopy times were obtained starting from the arterial puncture until removal of the introducer. Safety was evaluated by the occurrence of in-hospital vascular complications related to the puncture site and major adverse cardiovascular events (MACE) rate at 30-day follow-up. Major bleeding was defined as intracranial, intraocular, or retroperitoneal hemorrhage, clinically overt blood loss with a decrease in hemoglobin >3 g/dL, any decrease in hemoglobin >4 g/dL without overt bleeding, or transfusion of 2 or more units of blood products. Local hematomas were graded using EASY classification: type I- ≤5 cm diameter; type II- ≤10 cm diameter; type III- >10 cm but not above the elbow; type IV- extending above the elbow; type V- anywhere, with ischemic threat of the hand6. Access-site complications other than hematomas included arteriovenous fistulas, pseudoaneurysms, complication requiring surgery, or local infection requiring antibiotics. All patients signed a clarified term of informed consent.
            Data are presented as mean±1 standard deviation or frequencies. Statistical analysis was performed using SPSS software version 11.0 (Chicago, Illinois, USA). For comparisons of continuous variables, a 2-tailed, unpaired Student t test was used. Categorical data were compared using the Chi-square test or Fisher’s exact test. A value of p<0.05 was considered significant.

Results:
            From May 2007 to February 2009, 115 patients underwent 122 coronary procedures through the ulnar access, representing 2% of the total procedures carried out in this period, including 92 coronary angiographies, four of which in patients with previous coronary artery bypass grafting (CABG), four right and left heart catheterizations, 18 PCI, and eight ad hoc PCI. The clinical and procedural characteristics are expressed in Tables 1 and 2, respectively. The average age was 61.3 ± 11.1 years, with 58% of the patients being female and 31% diabetics.
            The use of the ulnar approach was due to a more superficial and more prominent pulse compared to the radial in 68.5% of the cases, thus aiming to avoid the occurrence of vasospasm and patient discomfort; occurrence of radial artery spasm in 12%; absence of radial pulse, with the presence of ulnar pulse and a positive reverse Allen’s test in 10%; extreme tortuosity of the radial artery in 6.5%, where the progression of the guide-wire was not possible; hypoplasia of the radial artery in 3% of the cases. The right ulnar artery was used in 91.5% of the procedures. To perform coronariographies, the use of 5Fr  right and left Judkins catheters were predominantly used (93%); while in PCI, 6Fr catheters with an internal lumen of 0.070-inch and stent implantation were used in 98% of the cases.

Table 1. Baseline demographic characteristics

PCI – percutaneous coronary intervention, CABG – coronary artery bypass grafting.

Table 2. Procedure characteristics

MI – myocardial infarction, PCI – percutaneous coronary intervention

The success rate of the procedures was 95%, with a need to change the access in six cases, of which five were achieved via the contra lateral radial access and one through femoral approach. Success was not possible in these cases due to failure in obtaining access (3), occurrence of severe spasm (1), a previous ulnar artery occlusion, in spite of an ample and palpable distal pulse (1), and extreme tortuosity of subclavian artery and ascending aorta, making it unsuitable to conclude the procedure (1). The complications related to the puncture site and the MACE rate at 30 days are expressed in Table 3. There were no cases

of major bleeding, pseudoaneurysm, arteriovenous fistula or lesion of the ulnar nerve. Hematomas were uncommon with only five cases of type I subcutaneous hematomas and one case of type IV, in an octogenarian patient who underwent rescue PCI after four hours of administration of streptokinase, with no need of blood transfusion or vascular repair surgery. The rate of slight to moderate spasm was 4%, with just one case (0.8%) of serious spasm, making it not possible to conclude the procedure, however without accompanying clinical complications. Two patients (1.6%) presented post procedure asymptomatic occlusion of the ulnar artery, with no additional evidence of hand ischemia. There were two in-hospital deaths, not related to the access route used, with one case consequent a refractory acute pulmonary edema following coronary angiography, in the presence of severe left ventricular dysfunction, and one case of post MI cardiogenic shock.

Table 3. In-hospital vascular complications and MACE at 30 days

Discussion:
            The radial approach, besides providing greater comfort to the patient, allowing early ambulation and hospital discharge, with consequent reduction of costs, promotes unequivocal reduction of vascular complications related to the puncture site. By reducing the occurrence of major bleeding, the use of the radial approach would present potential prognostic impact on survival free of major adverse events among patients undergoing invasive coronary procedures3,7. When its use is not possible, the ulnar approach presents itself as an attractive alternative, demonstrating similar anatomic and technical characteristics, and above all, being able to provide the same advantages offered by the radial approach.
            In our registry, 122 invasive coronary procedures performed via ulnar access, 21% of them therapeutic interventions, exhibited high success rates and virtually no incidence of major vascular complications related to the puncture site. There was a predominance of female patients (58%) and one third of the indications were composed of acute coronary syndromes, situations knowingly prone to greater risk of bleeding. In spite of this, the

rate of hematomas was less than 5%, mostly limited to small subcutaneous hematomas, with no cases of major bleeding or need of transfusion. Another aspect in our casuistic is that in the presence of palpable radial pulse the routine reverse Allen’s test was not checked8. Different from the superficial palmar arch, the deep palmar arch, originating from the radial artery, is angiographically complete in approximately 95% of the cases9. In addition, the large capacity of functional reserve of the circulation of the hand, represented by the recruitment of collateral branches, would represent a protecting factor against the occurrence of ischemic events10,11. In fact, we verified two (1.6%) asymptomatic occlusions of the ulnar artery at the moment of hospital discharge, without any ischemic repercussion or clinical manifestation, comparable to the rates of radial artery occlusion, around 1% to 7%, suggesting that the occlusion of the ulnar artery does not represent a concern in regard to the use of this approach4.
            The only selection criteria used in our analysis was the presence of a palpable ulnar pulse, regardless of its amplitude. Although Vassilev et al.(2008)¹² have reported a success rate of only 64% in unselected patients with palpable pulse, we obtained success in 95% of the cases, similar to Aptecar et al (2005)¹³ in a randomized comparative study between radial and ulnar approaches in patients with no previous evaluation of the quality of the pulse. Though it may be a controversial topic, it is believed that the ulnar artery usually possesses a larger diameter than that of the radial, besides presenting a smaller amount of α-receptors, making it less prone to spasms mediated by the adrenergic system14,15, and consequently less subject to failure in obtaining access or conclusion of the procedure.
            Since the pioneering report of the use of this new approach in 200116, in a reduced number of highly selected patients, centers that have stood out for the routine use of radial access have reported their experiences with the use of the ulnar technique in daily clinical practice, including performance of primary PCI in a set of acute myocardial infarction17. In common, the casuistics exhibit low occurrence of vascular complications related to the puncture site, usually represented by discreet hematomas, absence of ischemic complications, need of transfusions or injury to the ulnar nerve18,19.  
            Furthermore, radial-technique-trained operators have no difficulty in using the ulnar approach, just going through a fast learning curve related to the arterial puncture, as demonstrated by the lowest failure rate in obtaining access after performing more than 100 procedures4. However, the learning curve does not associate with delays or longer radiation exposition time, as demonstrated by the low fluoroscopy time in our analysis.
            The limitations of the study deal with a non-randomized prospective registry with limited casuistic, and the absence of follow-up with an image exam, such as Doppler ultrasound, which can underestimate the real occurrence of complications, such as arteriovenous fistula, pseudoaneurysm, and asymptomatic thrombotic occlusion, although at the 30-day phone contact we did not receive any additional complaints related to possible vascular and ischemic complications.

Conclusion:
            In conclusion the ulnar approach, although it represents a small portion of the procedures performed in centers where the radial approach is routine, presents itself as a feasible, safe and effective alternative to perform diagnostic and therapeutic coronary procedures. In face of the evidence that sustains the negative prognostic impact of major bleeding in the survival of the patients, it would represent a promising substitute to the radial approach, when its use is not suitable, without the need of conversion to the femoral approach.
Acknowledgements:
            We wish to thank David Lee Heddy for assistance in the final review of the manuscript.

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