# Venous Cannulation Site Stenosis and Risk of Recurrence: A New Hypothesis

## TL;DR

This study explores how stenosis at venous cannulation sites in hemodialysis patients increases the risk of recurrence and the need for repeated interventions.

## Contribution

The paper introduces a new hypothesis linking venous cannulation site stenosis to higher restenosis risk and the need for reintervention.

## Key findings

- Venous cannulation site stenosis (VCSS) was found in 25.6% of interventions and had a 35.7% reintervention rate.
- Restenosis at VCSS occurred most frequently at the same site (71.4% of reinterventions).
- Proximal arteriovenous fistulas were more likely to have VCSS and require reintervention.

## Abstract

Background: Maintenance of vascular access (VA) patency in hemodialysis (HD) can be challenging and may require multiple endovascular interventions. Changes in local hemodynamics and vessel wall injury caused by needle cannulation are related to a higher risk of neointimal hyperplasia and stenotic lesions. We proposed to analyze the incidence of venous cannulation site stenosis (VCSS) requiring angioplasty and the need for reintervention.

Methods: This is a retrospective cohort single-center study conducted on 431 HD patients with arteriovenous fistulas (AVFs) subjected to stenosis correction in 2022. Descriptive and comparative statistical analyses were performed.

Results: A total of 544 procedures on 438 AVFs were analyzed. The median age was 72 (62-80) years. The most commonly intervened autologous VA was the brachiocephalic (53.4%; n = 234), and of all AVFs, 19.6% (n = 86) were intervened on more than once. The most common stenosis locations were in not otherwise specified (NOS) venous segments (32.4%; n = 176), followed by cephalic arch (30.9%; n = 168) and venous cannulation sites (25.6%; n = 139). Of the AVFs with VCSS identified on first intervention (n = 98), 35.7% (n = 35) had to be reintervened, of which 71.4% (n = 25) recurred on the same site. The intervention on this kind of stenosis is more likely to occur in proximal AVF (p < 0.001) and has a higher risk of needing reintervention (p = 0.004).

Conclusions: There seems to be a relation between VCSS and risk for restenosis, highlighting the role of needle cannulation techniques (including length of cannulation tunnel) and blood flow at cannulation sites in the development of stenotic lesions.