Hemodynamic Characterization of Peripheral Arterio-venous Malformations.

Peripheral arterio-venous malformations (pAVMs) are congenital vascular anomalies that require treatment, due to their severe clinical consequences. The complexity of lesions often leads to misdiagnosis and ill-planned treatments. To improve disease management, we developed a computational model to quantify the hemodynamic effects of key angioarchitectural features of pAVMs. Hemodynamic results were used to predict the transport of contrast agent (CA), which allowed us to compare our findings to digital subtraction angiography (DSA) recordings of patients. The model is based on typical pAVM morphologies and a generic vessel network that represents realistic vascular feeding and draining components related to lesions. A lumped-parameter description of the vessel network was employed to compute blood pressure and flow rates. CA-transport was determined by coupling the model to a 1D advection-diffusion equation. Results show that the extent of hemodynamic effects of pAVMs, such as arterial steal and venous hypertension, strongly depends on the lesion type and its vascular architecture. Dimensions of shunting vessels strongly influence hemodynamic parameters. Our results underline the importance of the dynamics of CA-transport in diagnostic DSA images. In this context, we identified a set of temporal CA-transport parameters, which are indicative of the presence and specific morphology of pAVMs.

Ultrasound-assisted versus conventional catheter-directed thrombolysis for acute iliofemoral deep vein thrombosis: 1-year follow-up data of a randomized-controlled trial.

Essentials Acute iliofemoral deep vein thrombosis can be treated with catheter-directed thrombolysis (CDT). We performed a randomized trial comparing conventional CDT versus ultrasound-assisted CDT (USAT). Clinical and duplex sonographic outcomes at 12 months were similar in the CDT and USAT groups. In both groups, incidence of postthrombotic syndrome was very low with good quality of life. SUMMARY: Background In patients with acute iliofemoral deep vein thrombosis (IFDVT), catheter-directed thrombolysis (CDT) aims to prevent the postthrombotic syndrome (PTS). Adding intravascular high-frequency, low-power ultrasound energy to CDT does not seem to improve the immediate thrombolysis results but its impact on clinical outcomes at 12 months is not known. Patients/Methods In this randomized-controlled trial, 48 patients (mean age 50 ± 21 years; 52% women) with acute IFDVT were randomized to conventional CDT (n = 24) or ultrasound-assisted CDT (USAT; n = 24). In both groups, a fixed-dose thrombolysis regimen (20 mg r-tPA over 15 h) was used, followed by routine stenting of residual venous obstruction. At 12 months, PTS and venous disease severity (Villalta score and revised Venous Clinical Severity Score [rVCSS]), disease-specific quality of live (QOL; CIVIQ-20) and duplex-sonographic outcomes were assessed. Results Among the 45 surviving patients, 40 (89%; 95% confidence interval [CI] 76-96%) patients were free from PTS (defined as Villalta score < 5 points; 83%, 95% CI 61-95% in the USAT and 96%, 95% CI 77-100% in the CDT group), with a similar mean total Villalta score of 2.3 ± 2.9 vs. 1.7 ± 1.6, and a mean total rVCSS of 3.0 ± 3.5 vs. 2.7 ± 2.9 in the USAT and the CDT groups, respectively. Both groups had good disease-specific QOL with a CIVIQ-20 score of 29.4 ± 11.8 vs. 26.1 ± 7.8, respectively. Primary (100% vs. 92%) and secondary (100% vs. 96%) iliofemoral patency rates and presence of femoro-popliteal venous reflux (39% vs. 33%) were similar in both groups. Conclusion The addition of intravascular ultrasound energy to conventional CDT for the treatment of acute IFDVT did not have any impact on relevant clinical or duplex sonographic outcomes, which were favorable in both study groups. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier:NCT01482273.