#2559 “Remote software technology to assist clinical decision in vascular access surveillance: single UK centre experience”
Authors: Poulikakos Dimitrios , Eltahan Alshymaa , Pondor Zulfikar , Donne Rosemary , Lewis David , Raman Maharajan , Hinchliffe Paul , Cowperthwaite Jan , Gleave Paula 
Published: May 2024

Abstract

Background and Aims
Optimal arteriovenous access monitoring and surveillance aims for early detection of dysfunctional access, enabling pre-emptive referral for angioplasty or surgery to prevent access loss or thrombosis. Here we compared the addition of remote software surveillance to standard clinical care in our units.

Method
From January–December 2023 we conducted a 12-month prospective study of maintenance hemodialysis (HD) patients. We used Vasc-Alert software technology to assist clinical decision making for vascular access (VA) surveillance in 2 out of 5 HD units. In these units, vascular access risk score was calculated using Vasc-Alert software platform from routinely collected data from the dialysis procedure as previously described [1]. Patients with high Vasc-Alert access risk score (≥7) underwent clinical assessment and were referred for fistulogram if they met the relevant KDOQI criteria [2]. The following variables were collected from all 5 HD units: baseline permanent VA prevalence, subsequent VA events (stenosis or thrombosis), access abandonment (i.e. unsalvageable access loss), complication free days (CFD)-extended over one year (defined as days without serious vascular access events, radiological or surgical intervention, VA infection, hospitalisation or use of central venous catheter). Data was collected on patients who were pre-emptively referred for diagnostic fistulogram ± angioplasty but thrombosed while awaiting intervention. Median time interval from the date of fistulogram request till the date of confirmed thrombosed access was calculated. Comparison between HD units with Vasc-Alert use (Group 1) or without (Group 2) was performed using appropriate statistical tests depending on the type and distribution of the data. Survival analysis of post-intervention primary patency rate was conducted at 3 and 6 months defined as the time from the index procedure until the next access thrombosis or reintervention [3].

Results
There were 81 (53.6%) patients with permanent VA in group 1and 201 (59.3%) patients in group 2at the start of the study. We recorded 23 (28.4%) episodes of stenosis and 6 (7.4%) episodes of thrombosis in Group 1 and 40 (19.9%) episodes of stenosis and 21 (10.4%) episodes of thrombosis in Group 2 (p value 0.121 and 0.432, respectively). In Group 2, 11 patients (5.5%) developed repeated stenosis and 2 patients (1%) repeated thrombosis. In Group 1, 5 /6 (83%) cases preemptively referred for diagnostic fistulogram ± angioplasty developed thrombosis whilst awaiting elective intervention, compared with 4/21 (19%) in group 2 (p value = 0.008) (Fig. 1). The median time interval from the date of fistulogram request till date of thrombosed VA was 26 days with Interquartile range (IQR 25-75%) of 21-34 days. Group 1 had better post-intervention primary patency rate of VA (Fig. 2) and longer CFD-extended compared to group 2 (p values &lt; 0.001 and 0.002 respectively) (Table 1).

Conclusion
Our study shows that integrating Vasc-Alert technology into the VA surveillance program was associated with improved early detection of high-risk access, higher primary patency rates and CFD-extended. Additionally, our data emphasizes the need to enhance interventional radiology capacity for timely access intervention, to realise the true potential of Vasc-Alert technology in prevent access thrombosis.