A novel guidewire-integrated embolic protection filter device with a handy-folding system: In vitro and in vivo performance assessment.

OBJECTIVES: We developed a novel guidewire-integrated filter device with a handy-folding system (IFD: Inoue filter device). In vitro and in vivo studies were conducted to evaluate the feasibilityof the IFD. BACKGROUND: Although distal atheromatous and thrombotic embolizations remain unresolved critical issues during catheter interventions, distal protection devices are infrequently used partly because of reduced lower maneuverability. METHODS: In the in vitro experiment, we created an experimental circulation model composed of silicone latex tubes, a reservoir, and a roller pump. After the filter device was deployed in the tube, polystyrene fluorescent microspheres were injected and the capture rate was calculated. Ten trials were performed using the IFD and Spider FX. In the in vivo study, five independent operators deployed, and they retrieved the IFD in swine common iliac and internal carotid arteries. The procedural success rate as well as the delivery and retrieval time was evaluated. RESULTS: In the in vitro study, the mean capture rate was 94% and 35% in the IFD and Spider groups, respectively. In the in vivo study, all procedures were successful, with no complications. The mean delivery time was 281 ± 87 s and 194 ± 67 s and the mean retrieval time was 24 ± 9 and 13 ±1 s in the left internal carotid and the left common iliac arteries, respectively. CONCLUSION: Although further studies and improvements are required, the study results indicate that the IFD is feasible.

A novel detachable filter to prevent thromboembolism during endovascular surgery.

OBJECTIVE: Thromboembolism remains a serious complication during endovascular surgery. Commercially available filter devices, which are unified with the stenting systems, provide short-time performance owing to the adhesion of thrombus to the filters themselves. We have, therefore, developed a new detachable filter that can be used in all major aortic branches and shows greater longevity. The present study assessed the efficacy of the new detachable filter and examined the feasibility of deploying and retrieving the filters. METHODS: We first performed in vitro studies. Our experimental flow model used silicon tubing to simulate the aortic branches. Polystyrene-divinylbenzene microspheres (100 and 200 µm in diameter), which simulated embolic particles, were injected into the tubing after the detachable filter was deployed. The capture efficacy (number of microspheres trapped in the detachable filter/total injected microspheres) was calculated. In the in vivo studies, the detachable filters were implanted into the carotid, visceral, and renal arteries of 5 mongrel dogs. Angiography was performed every 30 minutes. At 5 hours after implantation, each detachable filter was retrieved by a gooseneck snare catheter. RESULTS: In the in vitro studies, our detachable filters showed high capture efficacy, capturing 99.2% of the 100-µm microspheres and 99.4% of the 200-µm microspheres. In the in vivo studies, all detachable filters were successfully deployed into the major branches. Each angiographic study revealed smooth flow without any embolic obstruction of the filter. At 5 hours after deployment, all devices were completely retrieved by the snare catheter without aortic injury. CONCLUSIONS: The new detachable filter showed high efficacy in capturing the particles. All detachable filters were successfully deployed for 5 hours, and the filters were retrieved from the aortic branches without any complications. This novel detachable filter can help prevent serious distal thromboembolism during endovascular surgery.

A novel approach to prevent spinal cord ischemia: Inoue stent graft with a side branch of small caliber for the reconstruction of the artery of Adamkiewicz.

OBJECTIVES: Paraplegia remains a serious complication after endovascular repair of thoracic aortic aneurysms, and it has been reported that paraplegia might be due to ischemia of the artery of Adamkiewicz. This study investigates the feasibility of an Inoue stent graft with a side branch of a small caliber for the reconstruction of the intercostal artery branching the artery of Adamkiewicz. METHODS: Branched Inoue stent grafts were implanted into the thoracic aorta and 11th intercostal artery of 5 mongrel dogs. The side branch measured 3 x 5 mm and contained a bare-metal coronary stent for fixing to the intercostal arterial wall. Aortography and selective angiography of the 11th intercostal artery were performed before and immediately after implantation and after 1, 4, 8, and 12 weeks. The luminal diameter of the intercostal artery before implantation was 2.4 +/- 0.3 mm. RESULTS: All stent grafts were successfully deployed. The main body of the graft did not develop endoleak or migrate, and the side branch remained patent for 12 weeks. Angiography performed 1 week postoperatively revealed smooth flow with slight stenosis (4.2% +/- 1.7%) along the side branches and the intercostal arteries in all dogs. Four weeks postoperatively, however, mild concentric stenosis (38% +/- 16%) along the side branch was observed in 4 of the 5 dogs. The percent stenosis at 8 and 12 weeks was 38% +/- 15% and 33% +/- 11%, respectively; these values were not significantly different from the value at 4 postoperative weeks. CONCLUSIONS: A novel Inoue stent graft with a side branch of small caliber was successfully deployed into the canine thoracic aorta and intercostal artery; the side branch remained patent for 12 weeks. This novel technique may enable endovascular reconstruction of the Adamkiewicz artery.