Role of peribrachial fat as a key determinant of brachial artery dilatation for successful arteriovenous fistula maturation in hemodialysis patients

Abstract

The functional quality of the inflow artery is one of the most important determinants of arteriovenous fistula (AVF) success. We evaluated the association of early optimal brachial arterial dilatation with a successful AVF maturation and assessed the role of peribrachial adipose tissue in determining brachial arterial distensibility. All patients underwent a preoperative vascular mapping with Doppler ultrasound (US), and only patients who had suitable vessels for AVF creation were enrolled (n = 162). Peribrachial fat thickness was measured using US. To evaluate the degree of brachial dilatation, follow-up US was performed at 1 month after surgery, and early brachial artery dilation was defined as the change in postoperative arterial diameter compared to the preoperative value. The primary outcome was failure to achieve a clinically functional AVF within 8 weeks. Nonfunctional AVF occurred in 21 (13.0%) patients, and they had a significantly lower brachial dilatation than patients with successful AVF during early period after surgery (0.85 vs. 0.43 mm, p = 0.003). Patients with a brachial dilatation greater than median level showed a 1.8-times higher rate of achieving a successful AVF than those without. Interestingly, the early brachial dilatation showed significant correlations with diabetes (r = −0.260, p = 0.001), peribrachial fat thickness (r = −0.301, p = 0.008), and the presence of brachial artery calcification (r = −0.178, p = 0.036). Even after adjustments for demographic factors, comorbidities, and baseline brachial flow volume, peribrachial fat thickness was an independent determinant for early brachial dilatation (β = −0.286, p = 0.013). A close interplay between the peri-brachial fat and brachial dilatation can be translated into novel clinical tools to predict successful AVF maturation. Arteriovenous (AV) fistula (AVF) is a preferred type of vascular access for hemodialysis (HD), because it is associated with fewer complications, improved access survival, and lower risk of patient mortality compared to AV graft or central venous catheter 1. Even in elderly patients, AVF remains the best mode of HD 2. However, maturation failure has been described as a major limitation of its use. To minimize AVF maturation failure, the rule of thumb is a judicious selection of adequate vessels and early detection of fistula complications. Doppler ultrasound (US) is widely available for preoperative vascular mapping; the minimum requirement for successful AVF creation is an arterial diameter of greater than 2.0 mm 3-6. However, AVF success rates as low as 60% are reported, even with arterial diameters above 2.0 mm 7. Therefore, we have to focus on the functional quality of vessels such as arterial blood flow or the artery's ability to dilate rather than indicating a threshold for the diameter of the vessels 8,9. Arterial distensibility is not necessarily related to the internal diameter and could be an important determinant of AVF success.

Brachial artery and cephalic vein diameter as maturation predictors of brachiocephalic arteriovenous fistula in end-stage renal diseases with type 2 diabetes mellitus

“…The mean brachial artery diameter in mature patients was higher than in immature patients but also not significant (4.18±0.67 vs. 3.90±0.61, p=0.082). 10 In our study, the threshold values for predicting AVF maturation were preoperative brachial artery diameter of 3.85 mm (sensitivity 78.7% and specificity 60%) and cephalic vein diameter of 2.45 mm (83% sensitivity and 72% specificity). In a study conducted by Ferring et al on 36 patients, the threshold value of the brachial artery was 3 mm, and the cephalic vein was 3 mm.…”

“…In Lee et al study, the AVF maturation failure rate was 13.59% out of 103 patients with DM. 10 Vernaglione et al found that AVF maturation failure was relatively high in women. This was thought to be caused by women generally having narrow blood vessels.…”

Impact of preoperative arterial and venous diameter on achievement of the adequate blood flow in arteriovenous fistula for hemodialysis

“…The diameter of the brachial artery has an important role for the functionality of AVF, and there are few studies in the literature that support this theory. 23 In addition, Kakkos et al presented that the diameter of brachial artery ≤4.1 mm (lowest quartile) was an independent predictor of AVF functionality (57% vs 83% for larger arteries, P = .017). 24 Our study is one of the few that showed significant association between preoperative diameter of the brachial artery and functionality of AVF.…”

“…There was also a significant positive correlation between the diameter of the brachial artery and achieved BF of AVF at the fourth week after creation. The diameter of the brachial artery has an important role for the functionality of AVF, and there are few studies in the literature that support this theory 23 …”