Patients develop aortic aneurysms due to high BP, injury, infection, genetic factors, or aging. Thus, they require endovascular repairs with aortic stent-grafts. It leads to complex surgeries involving laser fenestration and non-compliant balloon dilation. This study evaluates stent-graft responses to optimize therapeutic combinations in the future.
An ex-vivo study was designed for five aortic stent-grafts – Bolton RelayPlus, Cook Zenith Alpha, Medtronic Valiant, Jotec E-vita Thoracic 3G, and Vascutek Anaconda. Saline-submerged grafts and excimer laser were used for fenestration. Five rows of 5 small holes were created with one hole serving as the control. 4 holes in each row were dilated to specified normal pressure. The procedure used non-compliant balloons with 6,8,10 and 12 mm in diameter. Each stent-graft saline was collected and analyzed for debris. Tears’ length and direction, and each fenestrations’ area and diameter were measured. The process required scanning and light electron microscopes.
The fenestrations in all the stent-grafts were feasible and reproducible. The mean fenestration area for 6 and 8 mm balloons was in the 7.63 to 14.75 mm2 range. The 10 and 12 mm balloons caused a significant variability, tearing, and area increase. The Anaconda graft tore in the weft direction, while other grafts tore in the warp direction with 10 and 12 mm balloons. RelayPlus and Anaconda grafts dilation with 6 and 8 mm balloons had precise holes and minimal tearing. The filtrated saline for all stents had melted fiber remnants.
Balloon dilation and laser fenestration are simple, effective options. Large balloons with a diameter above 10 mm tore and destroyed the fabric. One can avoid significant tears using the recommended maximum dilation of 6 or 8 mm. New fabrics and stent-grafts have to be explicitly designed for fenestration to prevent complications.
Ref: https://journals.sagepub.com/doi/full/10.1177/1526602820981980
