Detailed ultrasonographic assessment of calcified arteries before arterio-venous fistula construction and fistula outcomes - a prospective observational study

Arterial calcifications (mainly mediocalcinosis) are highly prevalent in patients on hemodialysis. Severe calcifications reduce the possibility of a forearm arterio-venous fistula (AVF) construction, reduce maturation rates and increase the risk of hemodialysis access-induced distal ischemia (HAIDI). We report a prospective observational study on detailed ultrasound assessment of calcified arteries and outcomes of AVFs constructed in those conditions. In patients referred for vascular mapping, distal, mid and proximal radial artery (RA) as well as brachial artery were assessed for grade of calcifications (B-mode), homogeneity of color Doppler (CD) and compressibility of the artery. Pulsed-wave Doppler parameters at rest and during reactive hyperemia were also assessed. Based on the results, a site for AVF construction was planned. Outcomes of constructed AVFs were assessed. In 35 patients (mean age 68±13 years, 89% diabetics) we assessed 240 arterial sites, made 44 plans and constructed 31 AVFs/grafts. We observed several ultrasonographic phenotypes of calcified arteries. Severely calcified arteries (B-mode assessment) were heterogeneous when assessed for CD homogeneity and compressibility. Constructed AVFs/grafts had very good maturation rates (> 75%) even in a subgroup of radio-cephalic AVFs made on significantly calcified RAs (79%). There were no cases of clinically significant HAIDI. AVF construction with high likelihood of maturation and low likelihood of HAIDI in patients with significantly calcified arteries is possible, after proper evaluation of the artery. Homogeneity of CD and compressibility of the artery with ultrasound probe are useful additional criteria for assessing the suitability of a severely calcified artery for AVF construction.