Endovascular Aneurysm Sac Embolization for Treatment of Ruptured Aneurysms in the Aortoiliac Segment Using N-Butyl-Cyanoacrylate.

Background Aneurysmal rupture in the aortoiliac segment is a severe, life-threatening condition. Nowadays, in addition to surgical treatment, the implantation of a covered stent graft constitutes a feasible, minimally invasive treatment option. A novel approach is the add-on of transarterial aneurysm sac embolization with N-butyl-cyanoacrylate (NBCA). Here, we report our experience of performing this add-on embolization procedure after endovascular aneurysm repair for complex ruptured aneurysms of the aortoiliac segment. Material and Methods We describe six patients (mean age of 75.2 years; all male) with ruptured aneurysms in the visceral aortic and aortoiliac segment in whom a high-volume transarterial aneurysm sac embolization was performed as an add-on therapy to the implantation of an aortic prosthesis. The aim of this add-on intervention was to achieve the definite embolization of the aneurysmal rupture site and to ensure the best possible aneurysmal sealing. We report the feasibility, technical success, and considerations of using NBCA as well as clinical and follow-up imaging results, given their availability. Results Technical success was achieved in all cases. Clinical success was achieved in four cases. No periprocedural complications or reinterventions were reported. The mean full procedure time was 107.8 min. The mean radiation dose was 12,966.1 cGy/cm2. A mean amount of 10.7 mL of NBCA mixed with lipiodol in a 1:3 to 1:5 ratio was used for all patients. Available follow-up imaging up to 36 months after the procedure showed no aneurysm progression or endoleaks. In two patients, the NBCA cast had almost fully dissolved over the course of follow-up. Conclusions Our study underscores the notion that aneurysm sac embolization using high volumes of NBCA with ethiodized oil as an embolic agent is a feasible and add-on treatment option for optimizing the exclusion of the aneurysm from patients with ruptured aneurysms in the aortoiliac segment.

Comparison of second-generation stents for application in the superficial femoral artery: an in vitro evaluation focusing on stent design.

PURPOSE: To examine and compare in an ex vivo study different nitinol stent designs intended for the superficial femoral artery (SFA) with regard to the appearance of fracture. METHODS: Seven different 8-×40-mm nitinol stents were evaluated (Misago, Absolute, Smart, Luminexx, Sentinol, Lifestent NT, and Sinus-Superflex). Finite element analysis (FEA) was used for digitalized stent design comparison; the strain during stent movement was calculated for bending, compression, and torsion. Additional mechanical fatigue tests for bending (70°), compression (40%), and torsion (twisted counterclockwise by 180°) were performed up to 650,000 cycles or until a fracture was observed. RESULTS: The FEA bending test showed that only the Misago, LifeStent, and Absolute stents presented no zones of high strain; in the torsion test, the Smart stent also had no zones of high strain. Macroscopic evaluation after mechanical bending indicated that the LifeStent performed the best (no stent fracture after 650,000 cycles). Misago and Absolute stents showed fractures at 536,000 cycles and 456,667 cycles, respectively (range 320,000-650,000 cycles). After compression and torsion testing, Misago showed no stent fracture after 650,000 cycles. The worst performing stent was Luminexx during all test cycles. CONCLUSION: The 7 SFA stents showed differences in the incidence of high strain zones, which indicates a potential for stent fracture, as demonstrated by the mechanical fatigue tests. Differences in stent design might play a major role in the appearance of stent strut fracture related to restenosis and reocclusion.

Embolic protection devices for peripheral application: wasteful or useful?

Distal embolization following percutaneous intervention is a universal phenomenon that has been reported in various vascular beds. Distal emboli are also very common during lower extremity percutaneous peripheral interventions. Some data from case reports and registries are currently available. Clinical data have shown that the application of an embolic protection device in the lower limb arteries is safe. Prospective and, ideally, randomized trial data are warranted to justify the increased use of filters in lower extremity interventions, despite the obvious benefits that these devices provide. However, the clinical relevance of distal embolization in the lower extremity remains unquantified.

[Endovascular treatment of atherosclerotic arterial stenoses and occlusions of the supraaortic arteries: mid-term results from a single center analysis]. / Endovaskuläre Behandlung arteriosklerotisch bedingter arterieller Stenosen und Okklusionen der Aortenbogengefässe: Mittelfristige Ergebnisse einer Ein-center-Analyse.

OBJECTIVE: To determine mid-term patency rates after endovascular treatment of supraaortic atherosclerotic arterial stenoses and occlusions using percutaneous transluminal angioplasty (PTA) and stent placement. PATIENTS AND METHODS: During a period of 83 months, 48 patients (18 female, 30 male; mean age 61 years, range 31-82 years) were included into this prospective single-center study. Fifty-five lesions of the brachial and cephalic arteries (subclavian/axillary artery n = 42, innominate artery n = 7, origin common carotid artery n = 6) were treated using PTA (n = 38), PTA plus stent (n = 11) or primary stent placement (n = 6). For anticoagulation, patients received a bolus of heparin (5000 IU) intraarterially during the intervention followed by intravenous application for 24h. At discharge, life-time application of ASA (100mg/day) was initiated. Follow-up protocol included clinical examination, colour-coded duplex ultrasound and intraarterial angiography in case of re-stenosis. RESULTS: PTA and stent placement were technically successful in all patients (100%). No major complications occurred. Of seven patients presenting with total occlusions, six were treated with stent placement. Stent implantation was also performed in all lesions located at the origin of the supraaortic arteries (n = 6). In 38 lesions, the result of PTA was satisfactory. Mean follow-up time is 22 months (range 1-83 months). During follow-up examinations, re-stenoses occurred in 10 cases (at 1 month n = 2, at 6 months n = 2, at 12 months n = 3, at 24 months n = 3). In 9 lesions, re-interventions were performed (PTA n = 7; PTA plus stent n = 2). According to Kaplan-Meier life-table analysis, cumulative primary and primary assisted patency rates are 69.5% (patients at risk n = 15; standard error 9%) and 90.6% (patients at risk n = 16; standard error 6.3%) at 20 months, respectively. CONCLUSIONS: Endovascular treatment of atherosclerotic obstructive disease in brachial and cephalic arteries is a safe procedure showing promising mid-term patency rates.

Percutaneous intraluminal recanalization of long, chronic superficial femoral and popliteal occlusions using the Frontrunner XP CTO device: a single-center experience.

The purpose of this study was to examine the safety and efficacy of the Frontrunner XP CTO (chronic total occlusion) Catheter (Cordis) for recanalization of long femoropopliteal artery occlusions. A Frontrunner catheter was used to treat 26 CTOs in SFA after guidewire failure (68.3 +/- 8.8 years). Sixty-seven percent of patients had severe claudication. Critical lower limb ischemia with rest pain or minor tissue loss was present in three and eight patients, respectively. All the lesions were considered complex (TASC B, C, and D); 68% of the lesions were heavily calcified. The mean lesion length was 17.6 cm (range, 10-42 cm). The initial attempt to cross the occlusion with the CTO guidewire V18 was unsuccessful in 26 of 76 limbs (34.26%). A secondary attempt using the Frontrunner catheter (crossover approach, 27%; antegrade, 73%) performed in all 26 failed cases was successful in 17 limbs (65.38%), increasing the technical success rate to 88.12%. The main reasons for failure with the Frontrunner were inability to cross the lesion due to heavy calcification (six of nine) and inability to re-enter the true lumen after subintimal passage of the occluded segment (three of nine). The mean fluoroscopy time was 22.9 min. Minor complications included one distal extension of the dissection with involvement of the first popliteal segment and one perforation in the occluded segment. No major complications were seen. In conclusion, recanalization with the Frontrunner CTO catheter is a simple and safe method with a high technical success rate in the endovascular treatment of long superficial femoral artery occlusions and should be an alternative method after guidewire failure.

Reduction of cerebral embolization in carotid angioplasty: an in-vitro experiment comparing 2 cerebral protection devices.

PURPOSE: To evaluate the efficiency of 2 distal filtration devices designed for cerebral protection during carotid angioplasty in an in-vitro bench-top model. METHODS: After positioning the respective protection devices (RX Accunet and DynaCap) 5 cm distal to the bifurcation, embolization from carotid angioplasty was simulated by injecting polyvinyl alcohol particles in groups of small (150 to 250-microm diameter, approximately 500 particles), medium (250 to 355-microm diameter, approximately 200 particles), and large (700 to 1000-microm diameter, approximately 80 particles). Five milligrams of each group were injected separately into the internal carotid artery (ICA) model proximal to the protection filters. Particles passing the protection devices were caught in 100-microm filters and weighed. RESULTS: For small particles, the amount in the effluent of the ICA was 0.34+/-0.12 mg (6.8%) for the RX Accunet and 0.51+/-0.16 mg (11.2%) for the Occam DynaCap (p<0.05). For the other particle sizes, there was no statistical difference between the filters (p>0.05). CONCLUSION: In all test runs, neither of the tested devices prevented embolization completely, with approximately 3% to 6% of particles penetrating. For small particles, the lowest amount of particles passing the protection device was achieved using the RX Accunet system.

Comparison of carotid stents: an in-vitro experiment focusing on stent design.

PURPOSE: To examine and compare different carotid stent designs with regard to flexibility, adaptability (adjustability), conformability (compliance) to the vessel, and scaffolding to reduce plaque prolapse and embolization. METHODS: Six stents of different design were compared (Precise, Acculink, Protégé, Xact, Wallstent, and Cristallo Ideale). Optical microscopy was used to determine exact dimensions and scaffolding of each stent. Radial force was tested using a parallel plate setup, and flexibility (torsion and bending) was measured in water at body temperature. Particle penetration simulation was performed using plastic spheres from 1.5- to 6.0-mm outer diameter. RESULTS: Stent dimensions met the manufacturers' data; none of the products showed any failure during the test program. Cell sizes in the middle part of the stents ranged from 1.36 mm(2) (Wallstent) to 15.10 mm(2) (Acculink). Bending forces at 20 degrees /30 degrees ranged from 0.063 N / 0.074 N (Cristallo Ideale) to 0.890 N / 0.616 N (Xact); forces to achieve torsion at 10 degrees /15 degrees ranged from 0.032 N / 0.043 N (Acculink) to 0.905 N / 1.071 N (Xact). According to the parallel plate method, mean lowest force was measured for Xact (0.765 N), while the Wallstent had the highest force (2.136 N). Mean radial force measurements were lowest for Cristallo Ideale (9.06 N at mid part) and highest for Protégé (24.09 N). The Cristallo Ideale stent at mid part resisted penetration by all but the smallest plastic spheres (1.5-mm spheres penetrated only at 0.65 N); the Precise and Protégé stent had the highest variation in sphere penetration (1.5- to 4.0-mm spheres). Only the Acculink let 6-mm spheres penetrate. CONCLUSION: Despite comparable stent sizes, these carotid stents showed differences in behavior due to stent design. The open-cell design displayed the greatest flexibility and adaptability to the vessel but easily allowed particle penetration due to the open structure. Closed-cell designs had low flexibility and thus low adaptability to the vessel but high resistance to particle penetration due to the closed-cell design and high scaffolding. The hybrid stent design (Cristallo Ideale) was able to combine both the flexibility of an open-cell structure and the resistance to particle penetration of closed-cell structures.