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 for testing therapies. The model should mimic a variety of conditions, such as in vivo hemodynamics and native arterial structure and characteristics, avoiding animal experimentation.  Therefore, the aim of this study is to develop an ex vivo aneurysm model by vessel wall stiffening 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 distensibility. This sono-sensitive compound was activated by several ultrasound frequencies, resulting in stiffening of the treated arteries of which the most effective combination was selected. In a pulsatile ex vivo vascular bioreactor treated and control porcine carotid arteries were subjected to physiological conditions for 10 days. During culture, hemodynamics showed increased mean pressure and decreased pulsatility in treated arteries compared to controls. Change in vessel morphology and significant increase of distal diameter was observed in the treated arteries but not in the controls. Histology of treated arteries revealed dissection-like lesions distally and aneurysm-like structure proximally. Finally, a stent graft was deployed in one treated artery and cultured 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 could represent a promising tool for early stage device testing thereby reducing the need for animal studies.