In vivo intravascular ultrasound analysis of the absorption rate of the Angio-Seal vascular closure device in the porcine femoral artery.

AIMS: Device-based arterial closure is currently used to achieve haemostasis following percutaneous intervention. Little is known about the in vivo patterns of device absorption. We aimed to characterise the absorption dynamics following implantation of the Angio-Seal VIP closure device (AVCD) (St. Jude Medical, St. Paul, MN, USA) by using serial intravascular ultrasound (IVUS) and histology. METHODS AND RESULTS: Eleven AVCD were implanted following 6 Fr femoral arterial sheath in six pigs. Using carotid access, angiograms and IVUS were performed at baseline, 3, 5, 7, 14, 30 and 42 days following deployment. At termination, arteries were processed for histology at 14 (n=3), 30(n=4) and 42 days (n=4). By IVUS, following implantation the intravascular component (IC) area remained unchanged up to 14 days and decreased by 50% at 30 days and 95% by 42 days. By histology, there was a progressive decline in the IC area at 14 days and decrease by 30% at 30 days and 77% by 42 days. Histology demonstrated almost complete absorption of the IC and no signs of severe chronic granulomatous inflammation. CONCLUSIONS: IVUS serial imaging demonstrated almost complete absorption of the IC by 42 days in normal porcine femoral arteries. There was no evidence of severe chronic granulomatous vascular inflammation demonstrated by histology.

Development of a novel calcified total occlusion model in porcine coronary arteries.

OBJECTIVE: The objective of this study was to create a calcified total occlusion model in porcine coronary arteries using a catheter-based technique. BACKGROUND: Chronic total occlusion (CTO) represents 10-20% of all angioplasty cases and remains a challenge for interventional cardiologists. One of the limitations to successful recanalization is the failure to cross the wire through the CTOs. METHODS: Twenty swine underwent total occlusion creations in the coronary arteries. Via a carotid artery, previously prepared bone chips with absorbable sponge were delivered into the coronary arteries using catheter-based techniques. Twenty-eight days post creation, coronary angiography and histology were performed. RESULTS: Twelve animals survived and 10/12 had successful total occlusions. There were successful total occlusions in 100% (8/8) of the left anterior descending coronary arteries in the animals that survived. Angiography showed visible calcified total occlusions under fluoroscopy and also showed bridge collaterals distal to the occlusions (4/8) or contralateral collaterals from the right coronary arteries (4/8). The histology showed calcified nodules and abundant microchannels within the occlusions, media, and adventitia. CONCLUSIONS: We could successfully create a reliable and repeatable porcine coronary model of calcified total occlusions. This method can be utilized in many preclinical evaluations of CTO technologies.