Standardized Methodology for Duplex Ultrasound Examination of Arteriovenous Access for Hemodialysis: A Proposal of the French Society of Vascular Medicine and the French-Speaking Society of Vascular Access.

Duplex ultrasound (DUS) is an essential tool for characterizing and monitoring arteriovenous (AV) access for hemodialysis. The aim of the work described here, requested by the French Society of Vascular Medicine in collaboration with the French-Speaking Vascular Access Society, is to propose a standardized methodology for performing and documenting DUS, taking into account the variety of AV access techniques and the problems routinely encountered. A steering committee reviewed the literature and selected the relevant references. A draft was prepared, and all items with missing or conflicting data were submitted to a Delphi consensus. The final document was discussed and approved by all participants. The principles of DUS evaluation of AV access consist of examination of the afferent artery, the anastomosis and the entire venous drainage system. DUS uses B-mode ultrasound, color flow, pulsed wave and power Doppler analysis. DUS can be used in a variety of clinical situations, which can directly influence the methodology of the examination and the interpretation of the results. Blood flow should be assessed as it correlates with the risk of thrombosis. The measurement should be adapted to the different anatomical and hemodynamic conditions encountered. Characterization of stenosis should take into account the residual diameter of the drainage vein and its hemodynamic consequences. Other complications can be assessed with a standardized DUS examination. When performed according to a rigorous methodology, DUS of the AV access allows a comprehensive assessment of its functionality and eliminates the need for further invasive diagnostic procedures.

Duplex ultrasound-guided angioplasty of hemodialysis vascular access.

OBJECTIVE: Duplex ultrasound-guided angioplasty (DA) for hemodialysis vascular accesses remains questionable regarding its feasibility and safety. Minor complications (requiring no more treatment than nominal therapy) might be over-reported. Our hypothesis is that this procedure has no significant differences between observed rates and the recommended threshold of main outcomes of the procedure defined by the standards of arteriovenous fistulas (AVF) angioplasty. METHODS: In a single-center retrospective study, 298 DA performed on 141 patients from 2015 to 2019 were analyzed. Occluded AVF or concomitant use of radiographic guidance were excluded. Duplex ultrasound parameters were collected up to 1 month before, at the end of angioplasty, and on day 30 after the procedure. Complications were registered, and patency rates were studied at 24 months of follow-up. RESULTS: Anatomical success was achieved in 142 procedures (47.7%), clinical success in 284 (95.3%), and hemodynamic success in 283 (95.0%). Major complications-requiring at least a specific therapy-were reported in 8 procedures (2.7%) and minor complications-requiring no adjunctive therapy-in 157 (52.7%). At 24 months, overall postintervention primary patency was 34.0%, primary-assisted patency 87.4%, and secondary patency 92.5%. There were no significant differences of patency rates between groups with or without minor complications (P value for primary patency, 0.08; primary-assisted patency, 0.08; secondary patency, 0.23) or 30% residual stenosis (P value for primary patency, 0.82; primary-assisted patency, 0.46; secondary patency: 0.63). Duplex parameters further improved at postoperative day 30 after angioplasty. CONCLUSIONS: DA of AVF is feasible, safe-despite over-reported minor complications having no impact on postintervention patency rates-and efficient. A minor complication can be seen as an event without bad or good consequences. Anatomical definition of success does not fit on DA for hemodialysis vascular access. Further studies are required to define the duplex parameter threshold for efficacy.

Predictive Factors of Stent Patency in Iliofemoral Venous Diseases in a Multicentre Cohort Study.

OBJECTIVE: This study assessed primary stent patency predictive factors in three groups of patients with history of lower limb (LL) vein thrombosis: non-thrombotic iliac vein lesion (NIVL), acute deep vein thrombosis (aDVT), and post-thrombotic syndrome (PTS). METHODS: Consecutive patients from January 2014 to December 2020 with history of LL vein stenting from seven hospitals were included. All patients received an iliac or common femoral venous stent and had at least a six month follow up available with stent imaging. Anticoagulant and antiplatelet therapy strategies employed after venous stenting are reported and compared between groups. RESULTS: This study included 377 patients: 134 NIVL, 55 aDVT, and 188 PTS. Primary patency was statistically significantly higher in the NIVL group (99.3%) compared with the PTS group (68.6%) (p < .001) and the aDVT group (83.6%) (p = .002). PTS patients received a statistically significantly greater number of stents (p < .001) and had more stents below the inguinal ligament (p < .001). Median follow up was 28.8 months (IQR 16, 47). Discontinuation of antiplatelet therapy at the last assessment was 83.6% for NIVL, 100% for aDVT, and 95.7% for the PTS group (p < .001). Discontinuation of anticoagulation therapy at the last assessment was 93.2% for NIVL, 25.0% for aDVT, and 70.3% for the PTS group (p < .001). The only predictor of worse primary patency in the aDVT group was long term anticoagulation before stenting. CONCLUSION: Patients with NIVL have better primary patency after venous stenting than patients with venous thrombotic disorders. Long term anticoagulation before stenting was the only factor associated with poorer primary patency in patients with aDVT.

FOVELASS: A Randomised Trial of Endovenous Laser Ablation Versus Polidocanol Foam for Small Saphenous Vein Incompetence.

OBJECTIVE: To compare the outcomes of ultrasound guided foam sclerotherapy (UGFS) and endovenous laser ablation (EVLA) to treat isolated small saphenous vein (SSV) incompetence in a multicentre randomised controlled study (RCT; ClinicalTrials.gov identifier: NCT05468450). METHODS: Patients aged ≥ 18 years undergoing isolated SSV treatment (reflux > 0.5 seconds) were randomised to UGFS or EVLA. Patients treated with UGFS were allowed one additional truncal treatment at six weeks. Tributary treatments (phlebectomy or sclerotherapy) were permitted after six months. Participants were assessed at eight days, six months, and one, two, and three years. The primary endpoint was the absence of SSV reflux (> 0.5 seconds). Secondary outcomes included clinical scores and quality of life (QoL) scores. All analyses were done by intention to treat. RESULTS: Of 1 522 screened patients, 161 were randomised to UGFS (n = 82) and EVLA (n = 79). Only 3% of patients who received UGFS had the second (allowed) treatment and 86% of patients completed the three year study. Forty-one and 19 tributary treatments (by sclerotherapy) were performed in 27 UGFS patients (33%) and 15 EVLA patients (19%), respectively. The complete absence of reflux at three years was significantly better after EVLA (86%) than after UGFS (56%) (odds ratio [OR] 5.36, 95% confidence interval [CI] 2.31 - 12.44; risk ratio 1.59, 95% CI 1.26 - 2.01). Two deep vein thromboses (DVTs; one femoropopliteal and one gastrocnemius) and one endovenous heat induced thrombosis occurred in the EVLA group. Seven DVTs were seen in the UGFS group, including two partial popliteal DVTs and five gastrocnemius vein thromboses (four asymptomatic and incidental on day 8 screening). At three years, there was no difference between groups for the following: rate of visible varices (p = .87), revised Venous Clinical Severity Score (p = .28), and QoL (p = .59). Patient satisfaction scores were high in both groups (median score: EVLA 97/100 and UGFS 93/100; p = .080). Symptoms were significantly improved in both groups. (p < .001) CONCLUSION: Technical success was better for EVLA than for UGFS three years after SSV treatment. This agrees with studies that have reported on these treatments in the great saphenous vein. However, improvements in clinical outcome were similar for both groups.

Comparison of the Use of Arterial Doppler Waveform Classifications in Clinical Routine to Describe Lower Limb Flow.

BACKGROUND: Characterisation of arterial Doppler waveforms is a persistent problem and a source of confusion in clinical practice. Classifications have been proposed to address the problem but their efficacy in clinical practice is unknown. The aim of the present study was to compare the efficacy of the categorisation rate of Descotes and Cathignol, Spronk et al. and the simplified Saint-Bonnet classifications. METHODS: This is a multicentre prospective study where 130 patients attending a vascular arterial ultrasound were enrolled and Doppler waveform acquisition was performed at the common femoral, the popliteal, and the distal arteries at both sides. Experienced vascular specialists categorized these waveforms according to the three classifications. RESULTS: of 1033 Doppler waveforms, 793 (76.8%), 943 (91.3%) and 1014 (98.2%) waveforms could be categorized using Descotes and Cathignol, Spronk et al. and the simplified Saint-Bonnet classifications, respectively. Differences in categorisation between classifications were significant (Chi squared test, p < 0.0001). Of 19 waveforms uncategorized using the simplified Saint-Bonnet classification, 58% and 84% were not categorized using the Spronk et al. and Descotes and Cathignol classifications, respectively. CONCLUSIONS: The results of the present study suggest that the simplified Saint-Bonnet classification provides a superior categorisation rate when compared with Spronk et al. and Descotes and Cathignol classifications.