Clampless aortic punch system for making a large-diameter access route without side-biting clamp: a preliminary study

Although thoracic endovascular aneurysm repair (TEVAR) has been getting popularity as a less-invasive procedure, the treatment of thoracic aortic aneurysm with atherosclerotic aortic disease is still challenging. In hybrid TEVAR through the median sternotomy approach, side-biting clamp of the ascending aorta is often necessary for making an access route; however, it could cause embolic complication and aortic dissection. This study aimed to present the results of our preliminary study on the clampless aortic punch system (APS). The swine aorta was used as experimental specimen (diameter 16-20 mm). A 10-mm collagen-impregnated knitted Dacron graft was anastomosed to the aorta, and the APS was inserted into it. After piercing the aorta with the inner fish hook of the APS, the aortic wall was scooped out by an outer round cutter. Three different-angled cutters (0°, 15°, and 30°) were tested three times. The diameter of the punched-out lesion ranged from 6 to 9 mm (median 8 mm). Macroscopically, no major vessel injuries were seen 15° series, whereas minor or major vessel injuries were seen 30° and 0° series, respectively. Histological findings of 15° series confirmed the sharp edge of the stump and abrupt interruption of the elastic fiber without destruction of the normal three-layer structure of the aortic wall. This study suggests that our clampless APS could reduce the risk of stroke and aortic injury in hybrid TEVAR, and an animal study confirming its utility is now under consideration.