MO779: Benefits of a Nefrovascular Ultrasound Consultation: Results of 2 Years of Follow-Up
Authors: Burgos Martin Javier , Jesús Moyano Franco María , Virxinia Pol Heres Salia , Almenara Tejederas Marina , Salgueira Lazo Mercedes 
Published: May 2022

Abstract

BACKGROUND AND AIMS
The main vascular access for haemodialysis patients is the arteriovenous fistula (AVF). There is a high rate of early primary failure and loss of primary patency, therefore, vascular access monitoring is essential for the early diagnosis of complications and prolonging their survival.
Our objective is to analyse the results of a consultation for the review and follow-up of AVFs using colour-Doppler ultrasound, performed by the nephrologist.

METHOD
Retrospective descriptive study of vascular ultrasounds performed from January 2019 to January 2021. Including clinical and demographic variables of the patients, as well as ultrasound parameters. Data from the Review group were compared; ultrasounds performed 3–4 weeks after performing vascular access; versus Dysfunction group; whose patients were referred from the advanced chronic kidney disease (ACKD) consultations or from the different dialysis centres upon detecting any data of suspected vascular access dysfunction.

RESULTS
A total of 166 vascular ultrasounds were performed: 106 (64%) in the Review group and 60 (36%) in the Dysfunction of the AVF group.
A higher proportion of women was found in the Dysfunction group and upper mean age, close to the significance, P = 0.06 and P = 0.059 respectively. No significant differences were found with respect to other demographic characteristics in both groups (hypertension, diabetes, anticoagulant treatment and aetiology of kidney disease).
Regarding the type of vascular access, a lower proportion of radiocephalic AVFs was observed in the Revision group (65% versus 50%) and a greater number of elbow AVFs (humero cephalic, humero basilic and humero median) in the Dysfunction group (35% versus 50%) with differences close to significance, P = 0.057.
In the Review group, in 70.8% the findings were normal, in 24.5% lack of development was found, thrombosis in 9.4%, stenosis 6.6%, aneurysm 6%, oedema 17% and haematoma 6.6%. A 43% of the patients did not require to implement measures, in 42% exercise was recommended, in 6% repose of the AVF and 6 patients were requested fistulography and 3 were referred to cardiovascular surgery (CCV).
In the Access Dysfunction group, the ultrasound diagnosis was normal in 28%, thrombosis was objective in 25%, stenosis 37%, aneurysm 42%, oedema 17%, haematoma 22%. 37% were referred for fistulography and 15% for revision by CCV.
Regarding the ultrasound parameters, significant differences (P &gt; 0.05) were found in terms of AVF flow, proximal and distal resistance index and vein calibre, but not in terms of vein depth and anastomosis diameter.
A total of 28 fistulograms were performed, finding 86% agreement with the ultrasound findings. And in 93% the intervention was successful. Only 24% of the patients referred to the consultation required some type of intervention, and up to 65% were able to save the AVF, avoiding the realization of a new vascular access.

CONCLUSION
The systematic review after performing the vascular access made it possible to diagnose complications early and allow early intervention. It might be necessary to establish predictive criteria for vascular access dysfunction to individualize the follow-up for each patient, such as age, sex, or type of vascular access.
Systematized vascular ultrasound by the nephrologist is very useful to preserve the functionality of the vascular access. On the other hand, the Vascular Nephrodiagnosis Consultation can avoid performing invasive and unnecessary procedures for the patient.