#6345 HIGH BRACHIAL ARTERY BIFURCATION AND CLINICAL IMPLICATIONS UPON HEMODIALYSIS VASCULAR ACCESS PLANNING
Authors: Simões Pilar , Damas Juliana Francisca Da Costa e Silva Barbosa , Pereira Tiago Assis , Marouço Catarina , Sobral Mafalda , Corado Sofia , Carellha Sofia , Pena Ana , Da Costa Bernardo Do Sacramento Marques , Jorge Cristina 
Published: June 2023

Abstract

Background and Aims
Preoperative ultrasound mapping provides information about overall vessel, caliber, flow and anatomic variations, useful for hemodialysis (HD) vascular access planning. High bifurcation of the brachial artery (HBBA) is one of such variations, established early upon fetal development. Its implications in arteriovenous HD access creation are fairly unknown. The present work aims to characterize the prevalence and demographic characteristics of patients presenting with HBBA and study its impact upon HD vascular access planning, construction and patency.

Method
We developed a retrospective study focusing on 457 patients accessed from 2018 to 2021. Demographic data and presence of HBBA were registered as well as vessel diameter and peak systolic velocities (PSV) for brachial and radial arteries. Theoretical feasibility for each specific access (i.e., radiocephalic, brachiocephalic, brachiobasilic and prosthetic fistulae, according to ultrasound evaluation), final choice of access and 30-day patency were also gathered. Categorical variables are presented as frequencies and percentages and continuous variables as means and standard deviations or medians and interquartile ranges, as appropriate. Logistic regressions were adjusted considering sex, race, arm dominance and HBBA as independent variables.

Results
From a total of 457 patients, 193 (42,2%) were women and 264 (57,8%) were men. Mean age was 65,4 ±15,3 years. 383 (83,8%) were caucasian and 427 (93,4%) were right-handed. High bifurcation of the brachial artery was present on both arms of 6 (1,3%) patients, only one arm on 62 (13,6%) and on none of the remaining 389 (85,1%) patients. We found an association between being non-caucasian and presenting with HBBA (27% vs 12,5%, p-value = 0,01) but not with sex or arm dominance. Considering all patients, female sex was associated with smaller radial artery diameter, (2,0 ± 0,7 mm vs 2,2 ± 0,6 mm, p &lt; 0,01). HBBA was not associated with a significant difference on arterial diameters (adjusted for sex and race) and there were also no significant differences when comparing dominant vs non-dominant arms. We found no association between HBBA and the theoretical feasibility of a raciocephalic fistula but rather with the choice of arteriovenous graft as the only possible access (26,5% vs 19,5%, p-value = 0,044). A total of 379 (77,0%) patients proceeded to vascular access construction: 59 (15,6%) radiocephalic fistulas, 229 (60,4%) brachiocephalic fistulas, 31 (8,2%) brachiobasilic fistulas and 60 (15,8%) arteriovenous grafts were created, with no differences between HBBA and non-HBBA groups. There was, however, an association between non-caucasian patients and the choice for a more proximal access (p = 0,001) as well as the need for surgical or angiographic reintervention within 45 days after access creation (11 (5%) vs 6 (17,6%), p-value = 0,002).

Conclusion
Our study suggests that presenting with HBBA is not necessarily associated with lower quality vessels and less distal access construction. However, this variation seems to be more frequent among non-caucasians, who appear to receive more proximal accesses, in greater need for early intervention than their counterparts. Further investigation is necessary to understand if apart from diameter or PSV, HBBA could influence other determinants of access placement choice, such as distance from brachial artery to cephalic or basilic vein or risk of distal hypoperfusion syndrome.