Development of an ex vivo aneurysm model for vascular device testing

An ex vivo aneurysm model that closely resembles the in vivo situation can provide an important tool to test therapeutic approaches while avoiding animal experimentation. The model should mimic a variety of conditions, such as in vivo hemodynamics and native arterial structure and characteristics. The aim of this study was to develop an ex vivo aneurysm model by stiffening vessel walls to be used to assess treatment strategies. Porcine carotid arteries from slaughterhouse animals were used to evaluate the acute effect of different concentrations of Rose Bengal on vessel distensibility. Rose Bengal is a sono-sensitive compound that is activated by several ultrasound frequencies, resulting in stiffening of the treated arteries; the most effective combination of concentration and frequency was determined. In a pulsatile ex vivo vascular bioreactor, treated and control porcine carotid arteries were subjected to physiological conditions for 10 days. Treated arteries showed increased mean pressure and decreased pulsatility compared to controls. Changes in vessel morphology and a significant increase of distal diameter were observed in the treated arteries but not in the controls. Histology revealed distal dissection-like lesions and proximal aneurysm-like structure in the treated arteries. Finally, a stent graft was deployed and cultured in one treated artery, demonstrating the feasibility of testing endovascular devices in the model. In conclusion, we developed an ex vivo model reproducing the onset of aneurysm formation. This represents a promising tool for early stage device testing, thereby reducing the need for animal studies.