Transulnar access in patients with ipsilateral radial artery occlusion undergoing coronary angiography or angioplasty: 24-hour clinical and quantitative outcomes from the ULNART study

Background In patients with radial artery occlusion (RAO), upper-limb access options are limited. Ipsilateral transulnar access (TUA) represents a potential alternative; however, prospective data regarding procedural feasibility, vascular safety, and objective early neurofunctional impact remain limited. We evaluated procedural performance, vascular complications, and quantitative hand-function outcomes following ipsilateral TUA. Methods ULNART is a prospective cohort study of consecutive patients undergoing coronary angiography (CAG) or PCI via ipsilateral TUA. RAO was assessed by baseline color duplex ultrasonography (CDUS) and confirmed fluoroscopically through retrograde radial angiography after ulnar cannulation; CDUS was repeated within 24 hours to assess vessel patency and access-related changes. Grip strength, pinch strength, and sensory function (WEST) were assessed at baseline and at 24 hours, with within-patient comparison between access and contralateral hands. Vascular and neuromuscular complications were prospectively recorded. The study is registered on ClinicalTrials.gov. Results Forty-two patients were analyzed (65.5 ± 10.2 years; 71% male). Diabetes and hypertension were present in 71% and 86%, respectively; prior PCI in 79%. Patients had undergone 2.05 ± 1.15 prior catheterizations (range 1–5). Right-sided TUA was performed in 71% (ultrasound-guided in 64%). CAG was performed in 90%; 50% underwent PCI, including 17% CTO PCI. Technical success was 97.6%, with one crossover (2.4%). One major vascular complication occurred (EASY III hematoma, 2.4%). At 24 hours, hematomas were distributed as follows: none 59%, EASY I 24%, EASY II 14%, EASY III 2%, with no EASY IV–V events. Bleeding events were: none 86%, BARC 1 10%, BARC 2 2%, and BARC 3c 2% (adjudicated unrelated to the access technique). No arterial occlusion, pseudoaneurysm, arteriovenous fistula, hand ischemia, compartment syndrome, or need for surgical or endovascular intervention was detected clinically or by CDUS. Baseline grip strength was symmetrical (33.4 ± 10.6 vs 32.4 ± 11.3 kg). At 24 hours, access-side grip declined modestly but significantly (−5.4 ± 7.5 vs −1.4 ± 2.9 kg; mean paired difference −3.9 kg; p = 0.002); pinch showed a similar pattern (p = 0.002), whereas sensory changes were not significant (p = 0.318). In bilateral CTO procedures (n = 6), no significant asymmetry between TUA and contralateral TRA limbs was observed for grip (p = 0.249), pinch (p = 0.463), or sensory change (p = 0.317). Conclusions TUA ipsilateral to RAO demonstrated high procedural feasibility and low major vascular complication rates. Although a modest early reduction in access-side strength was observed, no objective sensory deficit or major neurovascular complication occurred. Controlled within-patient analyses support ipsilateral TUA as a safe and strategically valuable upper-limb alternative.