Association of Preexisting Arterial Intimal Hyperplasia with Arteriovenous Fistula Outcomes

Abstract

Background and objectives: Preoperative arterial function is associated with arteriovenous fistula (AVF) development. Because arterial pathology may correlate with its function, preexisting arterial intimal hyperplasia may be associated with AVF development.

Design, setting, participants, & measurements: Vascular specimens obtained from 125 patients (with minimal 2 mm arterial diameter and 2.5 mm venous diameter) undergoing AVF creation were quantified for arterial intimal hyperplasia, arterial medial fibrosis, arterial microcalcification, and venous intimal hyperplasia. A 6-week postoperative ultrasound quantified AVF diameter, blood flow, and stenosis. Clinical AVF maturation was assessed using a predefined protocol. In a prospective cohort study design, we investigated the association of preexisting arterial intimal hyperplasia with the postoperative AVF diameter, blood flow, stenosis, and clinical maturation failure, after controlling for baseline demographics, comorbidities, and preoperative vein diameter. Additional analyses evaluated whether other vascular pathologies interacted with arterial intimal hyperplasia in affecting AVF outcomes.

Results: The median intimal thickness of the native artery was 22.0 μm (interquartile range, 14.8-37.1 μm). The median postoperative AVF diameter was 4.8 (interquartile range, 3.7-6.8) mm, blood flow was 796 (interquartile range, 413-1036) ml/min, and stenosis was present in 37 out of 98 patients with ultrasound data (38%). AVF nonmaturation occurred in 37 out of 125 patients (30%). Preexisting arterial intimal thickness was not significantly associated with AVF blood flow (-12 ml/min; 95% confidence interval [95% CI], -55 to 30 ml/min), diameter (-0.04 mm; 95% CI, -0.21 to 0.14 mm), stenosis (odds ratio, 0.93; 95% CI, 0.75 to 1.14), or clinical maturation failure (odds ratio, 1.07; 95% CI, 0.90 to 1.28), all per 10 μm increase. There was no significant interaction of preexisting arterial intimal thickness and postoperative AVF outcomes with arterial medial fibrosis, arterial microcalcification, or venous intimal hyperplasia.

Conclusions: Preexisting arterial intimal hyperplasia is not associated with the 6-week AVF blood flow, diameter or stenosis, or clinical maturation when the preoperative arterial diameter is ≥2 mm.

Keywords: Calcinosis; Constriction, Pathologic; Demography; Hyperplasia; Prospective Studies; Tunica Intima; Veins; arteries; arteriovenous fistula; vascular access.

Graphical abstract

Figure 1.

Flow of the participants enrolled in a prospective study of AVF maturation. AVG, arteriovenous graft; Postop US, postoperative ultrasound; Vasc., vascular.

Figure 2.

Distribution of intimal thickness in preoperative arterial samples.

Figure 3.

Representative images of an artery with mild and severe intimal hyperplasia (IH). Hematoxylin and eosin stain shows (A) an artery with significant IH and (B) an artery with mild IH from patients receiving arteriovenous fistula creation surgery. (C and D) Masson trichrome stain of these samples shows their respective internal elastic lamina.