AIMS AND OBJECTIVES: To discuss the mechanical properties of stents and optimize the stents' selection scheme of overlapping segment through in vitro mechanical simulation of stent grafts. MATERIALS AND METHODS: The radial force tester was used to measure the radial force of different aortic covered stents, bare stents and the combination of the two. Linear relationship between the radial force at the distal end of the stent and oversize rate was plotted. The stent-induced aortic wall shear stress was evaluated intuitively by mechanical simulation. RESULTS: The radial force curve of the distal end of the thoracic aortic covered stent reflected the superelastic characteristics of aortic stent, and the characteristics was more obvious in stents composed of nickel-titanium than stainless; When different size of Hercules stents were combined with the same sized restrictive bare stent, the oversize rate of overlapping segment was the same, and the radial force was similar; At the initial compression diameter, the use of restrictive bare stent can improve the chronic outward force, but at high compression level, the chronic outward force of the overlapping segment was higher than that of the individual aortic covered stent. CONCLUSIONS: Based on in vitro mechanical simulation, the stent-vessel wall interaction after implantation can be more intuitively understood. The application of restrictive bare stents can change the radial force of the overlapping segment of the stents by reducing the oversize rate of the distal end of the stent-graft, but it can be harmful at a higher compression level.

BACKGROUND: The traditional treatment for aortic dissections (ADs) is a proximal repair of AD, but the long-term prognosis of residual distal dissection is unsatisfactory. The distal aortic intimal tear of distal aortic segmental enlargement (DASE) is evaluated via its size, with risk assessment, and assessed its risk, which will provide clinicians with diagnosis and treatment direction. METHODS: We analyzed 419 ADs patients who underwent radiographic examination of the aorta between September 1999 and May 2014. We recorded the area of the aortic intimal tear and divided it into two groups (75 patients in DASE group and 344 patients in non-DASE group). Logistics regression analysis or natural logarithm transformation was used to explore the potential risk of remaining distal tears to DASE, while the Logistic multiple regress equations were used to find out the independent risk factors. RESULTS: The postoperative large tear was defined as short diameter ≥5.0 mm. The independent risk factors of DASE are as follows: Short diameter of postoperative tears (odds ratios [ORs], 1.10;95% confidence interval [CI], 1.02–1.19; P < 0.0120); short diameter of the first tear after operation (OR, 1.12; 95% CI, 1.00–1.26; P < 0.0580) and the existence of large tears (OR, 1.13; 95% CI, 1.01–1.26; P < 0.0298). CONCLUSIONS: Our findings suggest that the size of the remaining tears and the existence of large tears are the key risk factors for patients with DASE. Patients with large remaining tears should be supervised regularly and treated timely.

Common femoral artery (CFA) aneurysms are rare with an unknown exact incidence and often found in elderly males with chronic diseases. Early recommendations are to repair aneurysms with a maximum diameter of ≥2.5cm. We present the case of a 37-year-old male with a right CFA aneurysm. Open surgical repair (OSR) consisting of aneurysmectomy and reconstruction of the femoral artery with a bifurcated prosthetic graft was applied. Our study details this case and thoroughly reviews on the treatment of femoral artery aneurysms in the literature. OSR and vascular reconstruction with interposition prosthetic graft were durable and associated with favorable outcomes.

Endovascular treatment is widely used for treating the subclavian artery pseudoaneurysm (SAP) because of its small trauma, fast recovery, exact effect, and low incidence of complications. However, when the systemic disease or infection that causes SAP is in the active phase, treatment of the primary disease is more critical. Surgical intervention should be performed after systemic symptoms have been controlled unless the situation is particularly critical. We introduced two cases of SAP caused by brucellosis and Behcet's disease and discussed the course of treatment.