VOLume flow assistance for optimizing outcomes of dysfunctional autologous arteriovenous fistula Angioplasty: the VOLA Pilot Study

Association of radiocephalic arteriovenous anatomical markers with post-angioplasty blood flow volume

BACKGROUND

Doppler ultrasound (DUS) blood volume flow (VF) calculation is the most reliable method for demonstrating the success of endovascular treatment of dysfunctional radiocephalic arteriovenous fistula (AVF). Due to the difficulty of this method for the interventionalist, VF-correlated markers are required during the procedure.

PURPOSE

To investigate the relationship between intraprocedural anatomical markers (AMs) and changes in VF induced by percutaneous transluminal angioplasty (PTA).

MATERIAL AND METHODS

The study included 56 patients with dysfunctional radiocephalic AVF who underwent PTA between September 2020 and 2022. The VF of all patients was measured using DUS before and 1 h after PTA. AMs were determined from 10 images, five before and five after balloon angioplasty.

RESULTS

The mean post-PTA VF was 637 ± 277 mL/min compared to baseline (151 ± 107 mL/min). Before and after balloon angioplasty, vein diameter (VD), artery diameter (AD), stenosis minimum luminal diameter (MLD), stenosis percentage (SP), and VF values were statistically significant (P = 0.001). Spearman's correlation analysis showed a positive strong linear relationship between VF and MLD (rs = 0.850, P <0.001), and a negative strong linear relationship between VF and SP (rs = 0.815). Receiver operating characteristic curve analysis showed that the sensitivity and specificity for VF ≥400 mL/min at cutoffs of SP <50% and MLD >2.5 mm were 81% and 82%, and 81% and 90%, respectively.

CONCLUSION

Among the AMs readily available during PTA, first MLD and then SP provided satisfactory results in predicting VF.

Results of a hemodialysis vascular access routine ultrasound surveillance protocol and frequency of surveillance guided pre-emptive access maintenance interventions

BACKGROUND

To evaluate the implementation of routine surveillance using ultrasound on hemodialysis vascular access (VA) outcomes and determine the number and frequency of corrective, surveillance-guided procedures performed.

METHODS

Multicenter, prospective, observational study that includes consecutive hemodialysis patients receiving therapy from native arteriovenous fistulae (AVF) or grafts (AVG). Participants were assigned to a routine VA Color Doppler ultrasound surveillance (DUS) protocol from January 2019 to December 2021. Patients were referred for corrective procedures (endovascular or surgical) based on clinical or DUS findings (pre-emptive procedures; PEP). Primary endpoint was the estimation of primary unassisted (PUP) and secondary patency (SP) rates. Secondary endpoints were the determination of the number and frequency of PEP and VA survival rates.

RESULTS

In total, 223 patients with 243 VA (192 AVF and 51 AVG) were included. Access PUP and SP rates were 83% and 93% at 12 months, 75% and 88% at 24 months, and 72% and 83% at 36 months follow-up. Autologous fistulae PUP and SP were 89% and 96% at 12 months, 81% and 93% at 24 months, and 80% and 89% at 36 months, respectively. Graft PUP and SP were 56% and 80% at 12 months, 44% and 65% at 24 months, and 39% and 54% at 36 months, respectively. In total, 56 corrective procedures (38/56 PEP; 65.5%) were performed (0.13 procedures/year), of which 34 were in AVF patients (0.09 procedures/year) and 22 in AVG patients (0.40 procedures/year). Overall, 33 VA losses occurred (0.06 failures/year), 17 in AVF (0.04 failures/year), and 16 in AVG patients (0.20 failures/year).

CONCLUSION

The use of DUS resulted in the timely diagnosis of dysfunction, satisfactory overall VA survival, and patency rates, with a low PEP frequency. Randomized controlled trials are required to establish the value of DUS surveillance on access patency and whether DUS-guided interventions could improve VA outcomes.