A New Flow-Diverter (the FloWise): In-Vivo Evaluation in an Elastase-Induced Rabbit Aneurysm Model

OBJECTIVE: We aimed to evaluate the efficacy and safety of a newly developed, partially retrievable flow-diverter (the FloWise) in an elastase-induced rabbit aneurysm model. MATERIALS AND METHODS: We developed a partially retrievable flow diverter composed of 48 strands of Nitinol and platinum wire. The FloWise is compatible with any microcatheter of 0.027-inch inner diameter, and is retrievable up to 70% deployment. The efficacy and safety of the FloWise were evaluated in the elastase-induced rabbit aneurysm model. The rate of technical success (full coverage of aneurysm neck) and assessment of aneurysm occlusion and stent patency was conducted by angiograms and histologic examinations at the 1-month, 3-month, and 6-month follow-up. The patency of small arterial branches (intercostal or lumbar arteries) covered by the FloWise were also assessed in the 5 subjects. RESULTS: We attempted FloWise insertion in a total of 32 aneurysm models. FloWise placement was successful in 31 subjects (96.9%). Two stents (6.2%) were occluded at the 3-month follow-up, but there was no evidence of in-stent stenosis in other subjects. All stented aneurysms showed progressive occlusion: grade I (complete aneurysm occlusion) in 44.4% and grade II (aneurysm occlusion > 90%) in 55.6% at 1 month; grade I in 90% and II in 10% at 3 months; and grade I in 90% and II in 10% at 6 months. All small arterial branches covered by the FloWise remained patent. CONCLUSION: A newly developed, partially retrievable flow-diverter seems to be a safe and effective tool of aneurysm occlusion, as evaluated in the rabbit aneurysm model.

Experimental Fusiform Aneurysm Model at Common Carotid Artery in Rat

PURPOSE: An ideal suturing material should be strong, easy to handle, should produce minimal tissue reaction and finally should disappear without a trace. Various micro-vascular suture materials have been produced in the past several decades in order to meet these demands. We have used nylon suturing material in experimental microsurgery because it is less expensive than polypropylene. After carotid artery end-to-end anstomosis, we found fusiform aneurysm incidentally. In this study 9-0 nylon (group I) and 9-0 polypropylene (group II) were compared to 10-0 nylon (group III), and 10-0 polypropylene (group IV) in order to survey the incidence of aneurysmal development in each material for use in microvascular surgery. METHOD: Forty Sprague-Dawley rats, 230 g to 350 g body weight, were used for this study. The carotid arteries were anastomosed end-to-end with 9-0 nylon, and 10-0 nylon, in addition to 9-0 polypropylene, and 10-0 polypropylene. The suture number of all arteries was 10 points except for two cases were 11 points due to uncontrolled bleeding. Specimens were harvested 1 week, 3 weeks, 6weeks and 10 weeks postoperatively. RESULT: The number of animals studied during the first week totaled 20 carotid arteries and they showed no interval change. After 3 weeks, we identified aneurysms in following cases: group I 3 cases, group II 2 cases, group III 1 case and group IV 1 case per five cases in each group. After 6 weeks, gross aneurysmal changes seen: group I, all (5) cases; Group II, 2 cases; group III, all (5) cases; Group IV, 3 cases. After 10 weeks, many aneurysms were observed: group I, all (5) cases; group II, all (5) cases; group III, 0 case; group IV, 2 cases. The aneurysms were measured and ranged in size from 1.3 mm to 8.1 mm. Histological analysis for inflammation, fibrosis and medial necrosis at the anastomosis site revealed no significant difference between same sized suture materials. If the experimental aneurysms were more than 5 times the diameter of the carotid artery, the aneurysms were considered to be experimental giant aneurysms. Seventy of our 34 experimental aneurysms were considered to be giant aneurysms. CONCLUSION: Our findings demonstrate that the development of aneurysms was related to size of the suture material and not the type of suturing material used. An ideal suture material for anastomosisof the carotid artery in the rat wasd a 10-0 monofilament suture material with suture numbers was above 10 points. We also made good aneurysm model. When we used 9-0 suture material and suture numbers were below 10 points multiple aneurysms developed. This model demonstrated the development mechanism of giant fusiform aneurysms.

Experimental Fusiform Aneurysm Model at Common Carotid Artery in Rat

PURPOSE: An ideal suturing material should be strong, easy to handle, should produce minimal tissue reaction and finally should disappear without a trace. Various micro-vascular suture materials have been produced in the past several decades in order to meet these demands. We have used nylon suturing material in experimental microsurgery because it is less expensive than polypropylene. After carotid artery end-to-end anstomosis, we found fusiform aneurysm incidentally. In this study 9-0 nylon (group I) and 9-0 polypropylene (group II) were compared to 10-0 nylon (group III), and 10-0 polypropylene (group IV) in order to survey the incidence of aneurysmal development in each material for use in microvascular surgery. METHOD: Forty Sprague-Dawley rats, 230 g to 350 g body weight, were used for this study. The carotid arteries were anastomosed end-to-end with 9-0 nylon, and 10-0 nylon, in addition to 9-0 polypropylene, and 10-0 polypropylene. The suture number of all arteries was 10 points except for two cases were 11 points due to uncontrolled bleeding. Specimens were harvested 1 week, 3 weeks, 6weeks and 10 weeks postoperatively. RESULT: The number of animals studied during the first week totaled 20 carotid arteries and they showed no interval change. After 3 weeks, we identified aneurysms in following cases: group I 3 cases, group II 2 cases, group III 1 case and group IV 1 case per five cases in each group. After 6 weeks, gross aneurysmal changes seen: group I, all (5) cases; Group II, 2 cases; group III, all (5) cases; Group IV, 3 cases. After 10 weeks, many aneurysms were observed: group I, all (5) cases; group II, all (5) cases; group III, 0 case; group IV, 2 cases. The aneurysms were measured and ranged in size from 1.3 mm to 8.1 mm. Histological analysis for inflammation, fibrosis and medial necrosis at the anastomosis site revealed no significant difference between same sized suture materials. If the experimental aneurysms were more than 5 times the diameter of the carotid artery, the aneurysms were considered to be experimental giant aneurysms. Seventy of our 34 experimental aneurysms were considered to be giant aneurysms. CONCLUSION: Our findings demonstrate that the development of aneurysms was related to size of the suture material and not the type of suturing material used. An ideal suture material for anastomosisof the carotid artery in the rat wasd a 10-0 monofilament suture material with suture numbers was above 10 points. We also made good aneurysm model. When we used 9-0 suture material and suture numbers were below 10 points multiple aneurysms developed. This model demonstrated the development mechanism of giant fusiform aneurysms.

Construct canine intracranial aneurysm model by endovascular technique / 介入放射学杂志

Objective To construct canine bifurcation aneurysms suitable for evaluating the exploration of endovascular devices for interventional therapy by endovascular technique.Methods The right common carotid artery of six dogs was expanded with a pliable balloon by means of endovascular technique, then embolization with detached balloon was taken at their originations DAS examination were performed on 1,2,3 d after the procedurse. Results 6 aneurysm models were created in six dogs successfully with the mean width and height of the aneurysms decreasing in 3 days.Conclusions This canine aneurysm model presents the virture in the size and shape of human cerebral bifurcation saccular aneurysms on DSA image, suitable for developing the exploration of endovascular devices for aneurismal therapy. The procedure is quick, reliable and reproducible.