RESUMEN
Endovascular aneurysm repair (EVAR) has disseminated rapidly as an alternative to open surgical repair for the treatment of abdominal aortic aneurysms (AAAs), because of its reduced invasiveness, low mortality, and morbidity rate. The effectiveness of the endovascular devices used in EVAR is always at question as postoperative adverse events can lead to re-intervention or to a possible fatal scenario for the circulatory system. Motivated by the assessment of the risks related to thrombus formation, here the impact of two different commercial endovascular grafts on local hemodynamics is explored through 20 image-based computational hemodynamic models of EVAR-treated patients (N = 10 per each endograft model). Hemodynamic features, susceptible to promote thrombus formation, such as flow separation and recirculation, are quantitatively assessed and compared with the local hemodynamics established in image-based infrarenal abdominal aortic models of healthy subjects (N = 10). Moreover, the durability of endovascular devices is investigated analyzing the displacement forces (DFs) acting on them. The hemodynamic analysis is complemented by a geometrical characterization of the EVAR-induced reshaping of the infrarenal abdominal aortic vascular region. The findings of this study indicate that (1) the clinically observed propensity to thrombus formation in devices used in EVAR strategies can be explained in terms of local hemodynamics by means of image-based computational hemodynamics approach; (2) reportedly prothrombotic hemodynamic structures are strongly associated with the geometry of the aortoiliac tract postoperatively; and (3) DFs are associated with cross-sectional area of the aortoiliac tract postoperatively. In perspective, our study suggests that future clinical followup studies could include a geometric analysis of the region of the implant, monitoring shape variations that can lead to hemodynamic disturbances of clinical significance.
RESUMEN
BACKGROUND AND OBJECTIVE: Venous thromboembolism (VTE), comprising deep-vein thrombosis (DVT) and pulmonary embolism (PE), is a major healthcare concern that results in substantial morbidity and mortality with great economic burden for healthcare systems. Hence, the need for effective and efficient treatment of patients with VTE is important for both clinical and economic reasons. The objective of this study was to evaluate the cost effectiveness of rivaroxaban compared to standard of care (SoC) with enoxaparin followed by dose-adjusted vitamin-K antagonists for the treatment of DVT and PE in Greece. METHODS: An existing Markov model was locally adapted from a third-party payer perspective to reflect the management and complications of DVT and PE in the course of 3-month cycles, up to death. The clinical inputs and utility values were extracted from published studies. Direct medical costs, obtained from local resources, were incorporated in the model and refer to year 2017. Both costs and outcomes were discounted at 3.5%. The incremental cost-effectiveness ratio (ICER) per quality-adjusted life year (QALY) gained was calculated. Probabilistic sensitivity analysis (PSA) was carried out to deal with uncertainty. RESULTS: The base-case analysis showed that rivaroxaban in 3- and 6-month treatment duration for DVT and PE, respectively, as this is the common clinical practice in Greece, was associated with a 0.02 and 0.01 increment in QALYs compared to SoC, respectively. Rivaroxaban was associated with a reduced total cost in DVT (85) but with an additional total cost in PE (2) compared to SoC. Therefore, rivaroxaban was a dominant (less costly, more effective) and cost-effective (ICER: 177) alternative over SoC for the management of DVT and PE, respectively. PSA revealed that the probability of rivaroxaban being cost effective at a threshold of 34,000 per QALY gained was 99% and 81% for DVT and PE, respectively. CONCLUSION: Rivaroxaban may represent a cost-effective option relative to SoC for the management of DVT and PE in Greece.
