Percutaneous Transulnar Arterial Approach for Coronary Interventions

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INTRODUCTION

Coronary diagnostics and interventions have come a long way. For decades, the femoral artery has been the access of choice, until the radial artery was found to be a viable alternative for coronary and non-coronary interventions. Early mobility, ease of access, easy hemostasis, and early ambulation were the major advantages that made this route a favorite for most of the interventionists globally. Catheters and hardware were designed particularly for a radial route, but the challenges that lay ahead were to come from its anatomy itself. Tortuosities and loops in the artery became one of the reasons for crossover to the femoral route, and thus giving away the advantages again owing to anatomical and physiological bottlenecks. Those who had mastered performing procedures through the wrist were not satisfied by crossovers. And thus, it gave birth to the usage of ulnar artery as an alternative to radial artery for coronary interventions. We present here our experiences and an analytical review of our transulnar journey, spanning nearly a decade of inhibitions and tentativeness of using it as an alternative, to an upfront route of choice based on arterial dominance.

MATERIALS AND METHODS

This retrospective analysis is based on interventions done through the transulnar route between January 2015 and December 2023. Both the operators in the study were experts in transradial procedures with experience of more than 5000 each radial procedures. A total of 150 percutaneous coronary interventions were assessed and analyzed. The cocktail regimen used for the ulnar artery was the same that we have been using for the radial artery: 4000 units of unfractionated heparin, 100 mcg of Nitroglycerine (NTG), and 250 mcg of diltiazem. The demographics were studied and some anatomical and physiological variables were reviewed. We also introduce, “the concept of dominance’’ for the first time and its relevance in choosing the route for access. The parameters that were analyzed were ease of access, fluoroscopy time, anatomical variables like loops and tortuosities, access site complications such as pseudoaneurysms and hematomas, and post-procedural spasms and occlusions. We also assessed the feasibility of the same-side ulnar access after a failed radial attempt.

RESULTS

Efficacy and anatomical factors

Arterial dominance [Figure 1] was assessed by palpation and was defined as the more intensely palpable pulse at the wrist. Ulnar dominance was seen in 57.6% of the cases. It took approximately 124 ± 30s to cannulate the artery. The right ulnar artery was the preferred route in 82% of cases. In 4% of the cases, crossover was done to the left radial route in 18%. No crossover was done to the femoral route. In 16 cases (10.7%), the same side (right side ulnar) ulnar was used after an abandoned radial route, owing to small caliber, spasm, or radial loops. We encountered spasm in the ulnar artery in just a single case, and 4 cases (2.6%) had loops and tortuosities. The mean fluoroscopy time for coronary angiography was 1.5 min [Table 1].

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Figure 1:

The concept of arterial dominance.

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DISCUSSION

Ulnar artery because of its deep location as compared to the radial artery has not been used as a route of access for coronary angiographies and interventions, although there have been anatomical studies to prove that it may be bigger in size than its radial counterpart, especially at the wrist [Figure 2]. One of the most common reasons of cross-overs from the wrist to the groin has been a failed radial access owing to spasm, loops, and tortuosities. We in our study observed that these anatomical aberrations were seen far less in the ulnar approach.

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Figure 2:

The ulnar route.

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The superiority of radial approach over the femoral route has long been established, and complications at the groin and retroperitoneal bleeds through the femoral route have been one of the reasons higher mortality and major adverse cardiac event (MACE).^[1-4] The perception of radial being the only route to heart through the wrist needs a change, and interestingly enough the paradigm is shifting.

Dahal et al. in their meta-analysis compared the success rates, efficacy, and safety of transradial and transulnar access.^[5] A total of 2744 patients from five clinical trials were included in this meta-analysis, with nearly an equal number of patients undergoing transradial and transulnar catheterizations (1360 and 1384, respectively).^[5-8] The primary outcomes were MACE, and the secondary outcome was the composite endpoint of access-related complications. Although the transulnar route resulted in higher rates of access site failure and crossover, it had similar efficacy (similar MACE rates), safety (similar access site complications), and procedural times as the transradial route. Another meta-analysis conducted by Fernandez et al., of six randomized controlled trials also supported the use of ulnar artery as an alternative to the radial access for cardiac catheterization.^[9] Transulnar access is associated with fewer vascular complications, less patient discomfort, and consequently shorter durations of hospitalization.^[9] Transradial access is not superior to transulnar approach when performed by an experienced operator.^[10,11] In 535 consecutive patients, in a study conducted by Geng et al., to assess the two approaches, a successful puncture of the target artery was achieved in 95.1% and 91.5% of the patients in the transradial and transulnar groups, respectively (P > 0.05).^[12] The utilization of ulnar artery (UA) as an access site increases the chance of success with forearm access and reduces the need for crossover to the femoral approach.^[13] Moreover, the artery is large enough to accommodate 7F sheaths and enable left main and bifurcation percutaneous coronary interventions (PCIs) with ease [Figures 3 and 4]. The learning curve of this approach after appropriate guidance could be fast and safe.

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Figure 3:

Same side ulnar route after an abandoned radial.

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Figure 4:

Same side ulnar hemostasis.

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We introduce the concept of dominance, meaning thereby that invariably one of the two arteries at the wrist is bigger. Hence, palpating both arteries should become a habit, and the more volume one can be chosen for cannulation. For interventionists who have been performing coronary interventions through the radial route, learning curve for mastering the skills for ulnar approach is fast and safe. There are however certain hindrances and challenges that need attention. The first is the deep location of the artery, and the second is its proximity to the ulnar nerve which may be injured while cannulation. Multiple jabs to the artery should be avoided and xylocaine for local anesthesia should be administered carefully. Post-procedure the wrist should be observed more carefully for any hematomas, as compression is sometimes not as snug as it is on the radial site.

The incidence of spasm and loops and tortuosities was almost none, which could perhaps give the ulnar route an initial advantage over the radial route. Our effort has been to find whether the ulnar route can be used as an upfront approach while performing coronary interventions through the wrist. Another issue closely related to this is the use of the same side ulnar approach after abandoning a failed radial attempt owing to spasms, loops, or difficult anatomy. Agostoni et al. in their study (the SWITCH registry) observed that in cases of failed radial sheath insertion, switching directly to the homolateral ulnar artery for percutaneous coronary procedures is feasible and appears to be safe, without cases of symptomatic hand ischemia in this series.^[14] In our study, we took homolateral ulnar artery approach in 16 cases and did not encounter any hand ischemia later [Figures 5 and 6]. However, there are certain technical modifications that can be done like taking out radial sheath just after the procedure and ulnar sheath once the hemostatis of the radial artery is completely achieved. In case of peripheral arterial disease, same-side cannulation should be best avoided.

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Figure 5:

7F and LMCA Intervention

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Figure 6:

7F and ulnar route.

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A study to compare ulnar with the radial approach is underway and shall put more light on the advantages of transulnar approach

CONCLUSION

Transulnar route is a safe and effective alternative to radial approach in coronary diagnostic and interventional procedures. The principle of arterial dominance at the wrist is a good way for selection of access route. With fewer tortuosities, loops and spasms, and a larger caliber than the radial artery, the ulnar route can be the first choice for coronary interventions through the hand/wrist.