Percutaneous Transulnar Artery Approach for Diagnostic and Therapeutic Coronary Interventions

The transradial approach for coronary diagnostic and therapeutic interventions is a well-established alternative to the conventional femoral and brachial approaches^1–5 and is now widely used in catheterization laboratories worldwide.⁶ Although the radial approach is technically more difficult, as shown by the learning cure seen with this technique even among operators who have extensive experience with the femoral or brachial approaches,^7,8 its growing popularity stems from major advantages over the transfemoral and transbrachial techniques. Bleeding and other vascular complications at the puncture site are significantly less common with the radial approach, most notably in patients receiving aggressive anticoagulant, fibrinolytic, and antiplatelet therapy.^5,9–11 Also, the transradial approach allows for earlier ambulation, resulting in a more comfortable post-procedural period, earlier patient discharge, and reduced costs.^4,9,10,12 As a result, patients overwhelmingly prefer the radial approach.^9,12 However, the radial approach does not seem suitable for 5–15% of patients undergoing cardiac catheterization for reasons including an abnormal Allen’s test;^10,13 significant anatomic variations such as loops, tortuous configurations, stenoses, hypoplasia, and aberrant origin, and vasospasm leading to radial artery access failure or failure to achieve coronary artery cannulation.^14–18 Although the ulnar (cubital) artery is usually the larger of the two terminal branches of the brachial artery,^19,20 it has received very little attention as a potential approach for cardiac catheterization. Recently, preliminary reports on small numbers of patients have suggested that the ulnar approach may be both feasible and safe for coronary angiography^21,22 and percutaneous coronary interventions.^22,23 The aim of the present prospective study was to assess the suitability of the transulnar approach for routine use when performing cardiac diagnostic and therapeutic interventions. Methods Patients. Consecutive patients referred to our institutions for diagnostic coronary angiography with or without subsequent coronary angioplasty were prospectively screened for suitability for the ulnar approach, defined as a palpable ulnar pulse and a positive Allen’s test. The Allen’s test involved compression of both the radial and ulnar arteries while closing and opening the hand several times to squeeze out the blood; the test was considered positive (normal) if the open palm recovered a normal color within 10 seconds of release of the ulnar artery compression only.^13,24,25 We also performed a reverse Allen’s test, in which compression to the radial, but not the ulnar artery, was lifted to test the collateral circulation supplied to the hand by the radial artery and palmar arches. Patients with known arterial circulatory disease in an upper limb, a history of coronary revascularization surgery with left internal mammary artery grafting, a need for simultaneous right heart catheterization, acute pulmonary edema, or cardiogenic shock were not screened for ulnar access. Patients who were screened and found eligible for ulnar access were included in the study. The study was approved by our local ethics committee. Written informed consent was obtained from all patients prior to study inclusion. Evaluation criteria. Evaluation criteria were recorded from the start of the procedure to the control forearm Doppler ultrasound scheduled 7–15 days after the procedure. Patients who did not have a follow-up Doppler ultrasound were interviewed by phone 15–30 days after hospital discharge. The primary evaluation criterion was occurrence of an access site-related event, defined as either a need to use another access site for any reason or occurrence of an access site complication, including bleeding, hematoma, ulnar artery thrombosis, ulnar artery rupture, arteriovenous fistula, pseudoaneurysm, and ulnar nerve injury. The number of needle punctures (from the first puncture to sheath insertion), time from first puncture to sheath insertion, total time for the procedure, and total time under fluoroscopy were secondary evaluation criteria. Procedural success of diagnostic procedures was defined as adequate opacification of both coronary arteries, and of the left ventricle cavity when required. For percutaneous transluminal coronary angioplasty, procedural success was defined as satisfactory balloon dilatation and/or stent implantation, leaving less than 30% of residual stenosis. In both cases, major cardiac or non-cardiac events included death, myocardial infarction, rescue bypass graft surgery, cerebrovascular event, and brachial or aortic dissection. Ulnar artery cannulation. The right arm was abducted and placed on a rest attached to the catheterization table, with the wrist hyperextended. Local anesthesia with 2% xylocaine was performed at the site where the ulnar pulse was strongest, 1–3 cm proximal to the pisiform bone. The ulnar artery was punctured with a 20 gauge x 2 inch entry needle, into which a straight 0.025 inch plastic mini-guidewire was inserted (Radiofocus Introducer II, Terumo Corporation, Tokyo, Japan). A 4 French (Fr) tapering introducer (Terumo Corp.) was placed on the 0.025 inch wire through a skin incision made by cutting gently with a surgical knife. Sodium heparin (3,000 IU) and verapamil (2.5 mg) were injected through the introducer. When required, a 5 or 6 Fr introducer over a 0.035 inch wire was substituted for the 4 Fr introducer. Analgesia and sedation with synthetic opioids and benzodiazepines was used as needed. Cardiac catheterization. For diagnostic procedures, we used 4 Fr diagnostic catheters (Terumo Corp.) or 5 Fr catheters (Cordis Corporation, Miami Lakes, Florida) with appropriate shapes. Coronary angioplasty was done with 6 Fr guiding catheters having an inner diameter of 0.07 inches (Medtronic, Inc., Danvers, Massachusetts; or Cordis Corporation) or 5 Fr guiding catheters having an inner diameter of 0.058 inches (Medtronic Inc.) or 0.056 inches (Cordis Corp.). The catheters were advanced over a standard 0.035 inch spring guidewire. Coronary 0.014 inch guidewires and rapid-exchange balloons were used according to standard procedures. Commercially available balloon pre-mounted stents were used, and direct stenting was performed when possible. Sheath removal and post-procedure management. Ulnar artery sheaths were removed immediately after the procedure and a hemostasis strap over a gauze wad was applied to the puncture site for 4 hours, followed by a non-occlusive pressure dressing. No compression devices were used. The patients were advised to restrict wrist movements and were allowed to walk and leave the hospital 4 hours after diagnostic procedures, if possible, and as dictated by the clinical situation after therapeutic procedures. After angioplasty, all patients received clopidogrel (300 mg at procedure completion, then 75 mg per day for at least 1 month) and long-term aspirin (100–250 mg per day). Follow-up ultrasound assessment. The first 100 patients were scheduled for routine Doppler ultrasound assessment of the forearm vessels 7–15 days after catheterization. Subsequently, Doppler ultrasound was scheduled only in those patients who underwent coronary angioplasty. For patients who underwent two separate transulnar procedures (elective or repeat angioplasty), Doppler ultrasonography was performed 7–10 days after the second procedure. When ulnar access failed, Doppler ultrasonography was not performed. Doppler ultrasonography was carried out by the referring cardiologists or by angiologists. Patency of the ulnar and radial arteries, presence of procedure-related complications at the access site (hematomas, dissection, thrombosis, arteriovenous fistulae or pseudoaneurysms), and, when possible, size of the ulnar and radial arteries at the wrist, were recorded. In patients who did not undergo follow-up Doppler ultrasonography, a phone interview was conducted 15–30 days after the procedure to evaluate symptoms or functional impairment at the puncture site, forearm, or hand. Results Study population. Between June 6 and September 30, 2003, 210 consecutive patients referred for diagnostic coronary angiography and/or angioplasty were screened for ulnar access eligibility. Outcomes in these patients are shown in Figure 1. Of the 210 patients, 38 (18%) had an absent or weak ulnar pulse to palpation, a negative reverse Allen’s test, or both, and were therefore managed using the radial (34) or femoral approach (4). Of the remaining 172 patients, 158 underwent catheterization by the ulnar approach. The other 14 (9%) patients were switched to radial access after access failure due to the inability to successfully puncture the ulnar artery in 12 patients, and persistent arterial spasm in 2 patients. In these 2 patients, the opposite arm radial artery was used. The access failure rate was 10% in the first 100 patients, and 5.5% in the last 72 patients. In the 158 patients catheterized via the ulnar approach, 173 procedures were performed, including 122 diagnostic coronary angiographies, 38 coronary angiographies followed by angioplasty in patients with acute coronary syndromes, and 13 elective angioplasties. Reasons for elective angioplasty were stable angina and lack of pre-treatment with clopidogrel (7 patients), acute coronary syndromes in which the medical treatment was first intended (3 patients), and angioplasty of a second artery performed in a separate procedure (3 patients). In these 13 patients, and in 1 patient who underwent a follow-up coronary angiography because of equivocal symptoms 35 days after angioplasty, the ulnar approach was used twice, on different days, and was successful on both occasions. Baseline demographic and clinical characteristics of the 158 patients who were catheterized via the ulnar approach are shown in Table 1. Males contributed three-fourths of the population (117/158, 74%) and 29 (17.6%) patients had diabetes. Sixteen patients (10%) weighed more than 100 kg and 4 (2.5%) patients less than 50 kg. Acute coronary syndrome was the reason for catheterization in 43 (27.3%) patients. As shown in Table 2, 51 angioplasty procedures were done in 48 (30.3%) patients (Table 2); three patients each had two separate angioplasty procedures. Of the 48 patients who underwent angioplasty, 41 (85%) presented with acute coronary syndrome, 23 (48%) with non-ST-elevation acute coronary syndromes and 18 (37.5%) with ST-elevation acute coronary syndromes. Systemic fibrinolysis was given to 8 (8/48, 16.6%) patients, and 11 (11/48, 22.9%) patients received anti-GPIIb/IIIa drugs before or during the procedure. The angiography data are shown in Tables 1 and 2. Procedural outcome (Tables 1 and 2). Ulnar artery cannulation was done on the right side in all the patients but one. The number of punctures and the sheath insertion time in the patients undergoing diagnostic procedures are shown in Table 1. Cannulation was achieved with the first puncture in 101 (63.9%) patients; two punctures were needed in 36 (22.7%) patients, three punctures in 13 (8.2%) patients, four punctures in 5 (3.1%) patients, and five punctures in 3 (1.8%) patients. All 158 patients catheterized via the ulnar approach met criteria for procedural success. Good-quality coronary angiography images were obtained for all diagnostic procedures (160/160); in 152 (95%) of these procedures, 4 Fr left Judkins, right Judkins, or Amplatz catheters were used, and in the remaining 8 (5%) patients, 5 Fr catheters were required to improve image quality. In 105 patients (65%), left ventricle angiography was performed in addition to coronary angiography through a pigtail catheter. In 3 patients, an aortic angiogram was obtained as well. Total procedure time and total fluoroscopy time are shown in Table 1. Of the 51 angioplasty procedures, 46 (90%) were performed using 6 Fr guiding catheters (90%) and 5 (10%) using 5 Fr guiding catheters. All 51 angioplasty procedures were successful. Stenting was performed in 65 of 71 (91.5%) of the treated lesions and was direct (i.e., without pre-dilatation) in 48 (67.6%) of these 71 lesions. Procedure time and fluoroscopy time are shown in Table 2. Slight or moderate spasm at the forearm, arm, or subclavian level occurred in 7 (4.4%) patients during coronary angiography (n = 3) or angioplasty (n = 4), not precluding completion of the procedure. In 1 patient, general anesthesia was required to relieve the spasm. Four patients complained of lightening-flash pain in the ulnar side of the hand caused by needle puncture of the ulnar nerve; the pain resolved before the end of the procedure, leaving no residual sensory or motor abnormalities. In all patients, the ulnar artery was pulsating to palpation after the procedure. None of the patients had symptoms or signs of hand ischemia. None of the 158 patients with successful ulnar artery cannulation experienced bleeding at the access site. Neither blood transfusion nor vascular surgery was required in any of the patients. No major adverse events occurred after diagnostic catheterization or angioplasty (Tables 1 and 2). Doppler ultrasound assessment and local complications (Table 3). Follow-up Doppler ultrasonography was performed in 124 (78%) of the 158 patients successfully cannulated via the ulnar artery; these 124 patients included 92% of patients treated with angioplasty, and 88% of the first 100 consecutive patients. Mean time to follow-up Doppler ultrasonography was 10 ± 8 days (range = 1–58 days). In 7 (4.4%) patients, insignificant subcutaneous bleeding or hematoma formation around the puncture site was observed. Asymptomatic ulnar artery occlusion occurred in 1 (0.8%) patient in whom Doppler ultrasonography showed retrograde collateral flow from the radial artery distal to the site of ulnar artery occlusion. In 1 patient, a pseudoaneurysm measuring 22 x 14 mm, with a communication 2.2 mm in diameter, was found 7 days after the procedure (diagnostic coronary angiography); prolonged tight compression was applied and resolution with thrombosis of the pseudoaneurysm was documented by a repeat Doppler ultrasound done 7 days later. Among the patients in whom ulnar access failed, 1 experienced rupture of the artery with a large hematoma, but did not require blood transfusion. Treatment consisted in manual compression. Repeat Doppler ultrasound assessments done 3 and 5 days later showed resolution of the hematoma with a patent ulnar artery that was very sinuous at the puncture site, as shown by forearm angiography performed after a transfemoral diagnostic procedure. Arteriovenous fistulae did not develop in any of our patients. The diameter of the ulnar and radial arteries at the wrist was measured in 102 (84%) of 124 ultrasound investigations (Table 3). Mean diameter was similar for the ulnar artery (3.03 ± 0.63 mm) and radial artery (3 ± 0.85 mm). As compared to the radial artery, the ulnar artery was larger in 54% of the 102 patients, the same size in 12%, and smaller in 34%. Of the 34 patients who did not undergo follow-up Doppler ultrasonography, 32 were interviewed over the phone 10–30 days after hospital discharge. None reported symptoms or functional impairment at the access site. Discussion Our findings indicate that the ulnar artery at the wrist is a valuable access site in routine cardiac catheterization for coronary angiography and/or percutaneous coronary interventions. In our large series of patients referred for coronary angiography and/or coronary angioplasty, ulnar artery cannulation was considered in 210 patients and performed in 172 patients. Ulnar artery cannulation was successful in 158 patients. Thus, in an intention-to-treat analysis, ulnar cannulation was used in 75.2% (158/210) of the patients. Given the preliminary nature of this study, this rate compares favorably with the radial approach, which has been found unsuitable in 5–15% of patients undergoing cardiac catheterization.^{10,13,16–18} Moreover, after successful ulnar artery cannulation, all diagnostic and therapeutic procedures (n = 173) were successful; thus, none of the patients required switching to the radial or femoral approach. Operators who have extensive experience with radial cannulation learn the ulnar approach easily, as shown by our data on the number of needle punctures, sheath insertion time, procedure time, and fluoroscopy time, which compared favorably with published data on the radial approach.^5,9,11,26 However, the decreasing rate of access failures over time showed that a learning curve occurred. All diagnostic coronary angiographies were performed using conventional 4 or 5 Fr Judkins or Amplatz catheters, which produced satisfactory or optimal coronary opacification. Coronary angioplasties were performed successfully in a variety of clinical settings in our series, with conventional 6 Fr Judkins left and right, Amplatz left and right, or multi-purpose guiding catheters, which provided adequate support for balloon angioplasty and stenting, although most of the available diagnostic and guiding catheters are not designed for upper limb approaches. Cardiac catheterization through the ulnar approach was safe, as shown by the extremely low rate of local complications and the absence of systemic or cardiac procedure-related complications. Thus, asymptomatic ulnar occlusion was found at the time of routine Doppler ultrasonography in a single patient who had undergone diagnostic coronary angiography. Ulnar occlusion may have occurred in some of the patients who did not undergo follow-up Doppler ultrasonography, but none of these patients reported symptoms or signs of hand ischemia when interviewed over the phone. Moreover, of the 13 patients, each of whom had two separate procedures including a second or elective angioplasty, 12 underwent follow-up Doppler ultrasonography, which consistently documented patency of the ulnar artery. The low incidence of asymptomatic ulnar occlusion in our study compares favorably with the 1–7% incidence of asymptomatic radial occlusion reported with the transradial approach.^6,27–30 Thus, ulnar thrombosis does not appear to be a concern with the transulnar approach. In keeping with data on the radial approach, bleeding at the access site was extremely uncommon in our study. A single patient experienced the development of a significant forearm hematoma which did not require surgical drainage or blood transfusion; the cause was arterial wall rupture during an unsuccessful attempt at ulnar artery cannulation. The only other vascular complication in our series was a single case of pseudoaneurysm, which resolved after prolonged tight compression. Although a major concern exists about the possibility of nerve damage induced by puncture, bleeding, or hemostasis, injury to the ulnar nerve, which runs parallel to the ulnar artery and along its medial border, was not observed in our study. Thus, the ulnar approach seems to share a number of the major advantages of the radial approach, including easy hemostasis and a very low incidence of local complications, most notably in patients receiving aggressive anticoagulant, fibrinolytic, and antiplatelet therapy.^5,9–11,26 An important issue is whether learning to use the ulnar approach is worthwhile, i.e., whether the ulnar approach offers meaningful benefits over conventional approaches. Several considerations support the use of the ulnar approach. First, the ulnar artery is usually larger than the radial artery, as evidenced by anatomic and angiographic measurements.^19,20 Thus, the ulnar pulse is quite often stronger and easier to feel than the radial pulse. In many cases, hyperextension of the wrist markedly facilitates ulnar pulse perception and ulnar artery cannulation. In our study, whereas ultrasound measurements showed similar mean diameters for the ulnar and radial arteries at the wrist (3.03 ± 0.63 mm and 3 ± 0.85 mm, respectively), the ulnar artery was larger than the radial artery in more than 50% of cases and was similar in diameter in an additional 12% of cases. This may explain why ulnar artery spasm was not a major problem, even when using 6 Fr catheters. Second, the hand has a dual blood supply consisting of the ulnar artery which branches out into the superficial palmar arch and the radial artery which gives the deep palmar arch. Both arches constitute functionally important arterial connections between their major sources, as they protect the hand against ischemia if one of the source arteries is occluded. The superficial palmar arch varies substantially across individuals. Arch completeness on the radial side is extremely variable. In an anatomical study of 200 subjects, the superficial palmar arch (primarily ulnar) was absent in 32% of individuals, whereas the deep arch (primarily radial) was absent in a single subject.31 The superficial palmar arch is completed by branches from the deep palmar arch, radial artery, or median artery in 78.5% of patients; this leaves 21.5% of patients with “incomplete” superficial arches; in contrast, the deep palmar arch is completed by the superior branch of the ulnar artery, inferior branch of the ulnar artery, or both, in 98.5% of patients.32 Finally, in an angiographic study, the deep palmar arch was complete in 95% of individuals and the superficial palmar arch in only 40–80% of individuals.²⁰ The greater prevalence of radial collateral support than ulnar collateral support suggests that ulnar cannulation may be preferable over radial cannulation. Third, failure of the radial approach may occur as a result of several factors such as access site failure, reported in 4–5% of patients,^10,15,27 anatomic variations, local scarring or previous hand injury, synovial cysts, and local hematomas due to previous intravenous line placement or artery punctures for blood gas measurement. In patients with these factors, the ulnar approach may deserve to be considered before the femoral approach. Fourth, although silent radial artery occlusion after transradial coronary interventions occurs in 1–7% of cases,^6,9,28–30 ischemic complications at the hand are extremely rare.²⁸ However, the Allen’s test may produce a false-positive result in 3–4% of cases, as compared to angiography or ultrasound findings.^30,33 Thus, ischemic complications can be expected in 0.06–0.3% of patients who have a positive Allen’s test. Given this risk of hand ischemia, the ulnar approach may be preferable as a means of avoiding thumb-forefinger pinch impairment, which is a manifestation of radial artery impairment. Finally, previous transradial catheterization reduces the rate of early graft patency and causes intimal hyperplasia when the radial artery is used as a bypass conduit for myocardial revascularization.³⁴ As radial artery conduits are being increasingly used for coronary bypass surgery,^35–37 the ulnar artery approach may be valuable as a radial artery-sparing procedure. Conclusion In summary, the results of this study show that the transulnar approach is a useful alternative for routine diagnostic and therapeutic coronary interventions. In our experience, when performed by operators who have performed large numbers of transradial cannulations, the ulnar artery can be easily and safely cannulated in the vast majority of patients, with the same advantages and limitations as the radial approach. Despite the extremely low incidence of access-site vascular complications, we strongly recommend that the integrity of the palmar arch collateral support be documented before ulnar cannulation is attempted, particularly in patients with a history of ipsilateral radial cannulation. These patients run the risk of double-vessel closure, with potentially severe consequences. Although the Allen’s test should be sufficient, we recommend avoiding the ulnar approach in this patient population. Acknowledgments. We wish to acknowledge Gil Mehalin and Elke Seifert for technical assistance, and Dominique Salamite and Céline Ayraud for their enthusiastic secretarial assistance.

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