Stefan Müller-Hülsbeck

Universitätsklinikum Schleswig - Holstein, Kiel, Schleswig-Holstein, Germany

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Publications (44)115.67 Total impact

  • Article: MISAGO 2: One-Year Outcomes After Implantation of the Misago Self-Expanding Nitinol Stent in the Superficial Femoral and Popliteal Arteries of 744 Patients.
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    ABSTRACT: Purpose: To evaluate the safety and efficacy of the Misago self-expanding rapid-exchange nitinol stent system for the treatment of femoropopliteal occlusive disease in a prospective multicenter observational trial (ClinicalTrials.gov; identifier NCT01118117). Methods: Between April and October 2008, the registry enrolled 744 patients (496 men; 69±10 years) who had symptomatic ≥70% stenosis or occlusion of the superficial femoral or popliteal arteries treated with the Misago stent. Mean length of the 750 lesions was 63.9 mm; 282 (37.6%) vessels were completely occluded. Primary study endpoints were the need for target lesion revascularization (TLR) and event-free survival rates for the assessment of efficacy and safety, respectively. At 6 and 12 months post intervention, clinical symptoms of recurrent ischemia and/or claudication, Rutherford category, and ankle-brachial index (ABI) at rest were assessed. Results: In the study period, 945 stents were successfully deployed in the 750 lesions. The overall TLR rate was 10.1% among 671 (90.3%) patients evaluated at 1 year [3.1% among 709 (95.3%) patients at 6 months]. Event-free survival at 12 months was 84.9%. Mean ABIs improved by ≥0.1 in three quarters of the patients (76.0%) over 12 months. The Rutherford grade improved or remained stable in the majority of patients (95.5%) after 1 year. Stent fractures (13 grade 1, 2 grade 2) in 3.1% of stents examined radiographically (n=484) at 1 year were not related to any clinical events. Primary patency was recorded in 574 (87.6%) patients evaluated at 1 year post procedure. Conclusion: The Misago rapid-exchange nitinol stent showed promising efficacy and safety results, with a low stent fracture rate, in patients with femoropopliteal disease, making it a safe and reliable treatment option.
    Journal of Endovascular Therapy 12/2012; 19(6):774-84. · 2.86 Impact Factor
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    Article: Stent-protected carotid angioplasty using a membrane stent: a comparative cadaver study.
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    ABSTRACT: To evaluate the performance of a prototype membrane stent, MembraX, in the prevention of acute and late embolization and to quantify particle embolization during carotid stent placement in human carotid explants in a proof of concept study. Thirty human carotid cadaveric explants (mild stenoses 0-29%, n = 23; moderate stenoses 30-69%, n = 3; severe stenoses 70-99%, n = 2) that included the common, internal and external carotid arteries were integrated into a pulsatile-flow model. Three groups were formed according to the age of the donors (mean 58.8 years; sample SD 15.99 years) and randomized to three test groups: (I) MembraX, n = 9; (II) Xpert bare stent, n = 10; (III) Xpert bare stent with Emboshield protection device, n = 9. Emboli liberated during stent deployment (step A), post-dilatation (step B), and late embolization (step C) were measured in 100 microm effluent filters. When the Emboshield was used, embolus penetration was measured during placement (step D) and retrieval (step E). Late embolization was simulated by compressing the area of the stented vessel five times. Absolute numbers of particles (median; >100 microm) caught in the effluent filter were: (I) MembraX: A = 7, B = 9, C = 3; (II) bare stent: A = 6.5, B = 6, C = 4.5; (III) bare stent and Emboshield: A = 7, B = 7, C.=.5, D = 8, E = 10. The data showed no statistical differences according to whether embolic load was analyzed by weight or mean particle size. When summing all procedural steps, the Emboshield caused the greatest load by weight (p = 0.011) and the largest number (p = 0.054) of particles. On the basis of these limited data neither a membrane stent nor a protection device showed significant advantages during ex vivo carotid angioplasty. However, the membrane stent seems to have the potential for reducing the emboli responsible for supposed late embolization, whereas more emboli were observed when using a protection device. Further studies are necessary and warranted.
    CardioVascular and Interventional Radiology 04/2012; 29(4):630-6. · 2.09 Impact Factor
  • Article: Percutaneous transluminal angioplasty versus turbostatic carbon-coated stents in infrapopliteal arteries: InPeria II trial.
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    ABSTRACT: To determine the clinical outcome and the success of stent application for high-grade lesions of the infrapopliteal arteries compared with treatment with percutaneous transluminal angioplasty (PTA) in critical limb ischemia (CLI). In this ethics board-approved randomized prospective study, PTA or stent application was performed on 131 lesions in 88 patients with CLI. The primary end points were clinical improvement after endovascular treatment and limb salvage rate. Secondary end points were defined by the minimal lumen diameter (MLD) before and after the revascularization procedure, percentage of residual diameter stenosis (DS), binary restenosis rate (>50% DS and >70% DS), and incidence of target lesion revascularization at 9-month follow-up. At 3 months, the clinical status in the PTA group was less improved than that in the stent group (P = .008). At 9 months, there had been five minor and two major amputations in the PTA group and five major and five minor amputations in the stent group. MLD was significantly larger and the percentage of DS was significantly less in the stent group at completion angiography. At 9 months, the angiographic control showed better trends for the stent group in comparison to the PTA group despite that no significant differences were detected (MLD, 1.19 mm ± 0.92 vs 1.02 mm ± 1.02; DS, 38.68% ± 25.47 vs 43.31% ± 28.37). Infrapopliteal stent application is an effective treatment modality in CLI. The PTA and stent groups were essentially equal at 3 and 9 months except for the difference in clinical improvement in the stent group at 3 months.
    Radiology 11/2011; 261(2):634-42. · 5.73 Impact Factor
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    Article: Final results of the protected superficial femoral artery trial using the FilterWire EZ system.
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    ABSTRACT: The purpose of this study was to evaluate the safety and efficacy of debris-capture for distal protection using the FilterWire EZ Embolic Protection System (Boston Scientific, Mountain View, CA) with the additional aim to further define the incidence of distal embolization during superficial femoral artery (SFA) interventions. A prospective, single-centre registry was designed to evaluate the performance of the FilterWire EZ in capturing debris during standard SFA percutaneous intervention. The PRO-RATA study included 30 patients suitable for PTA (Fontaine IIb to III or Rutherford I to II classification). The primary end points were occurrence of distal embolization or decreased runoff, improvement in ankle-brachial index ankle-brachial index (ABI) after the procedure, and number of filters containing emboli. Secondary end points included major adverse events (i.e., procedure- or device-related death and/or clinical target lesion revascularisation), device delivery, deployment success, and incidence of embolic recovery (patients with device success exhibiting embolic protection in the filter). Procedural success was determined as ≤30% residual stenosis with no worsening of distal runoff as determined on angiography. A total of 29 patients (age 66.2 ± 12 years; total no. of limbs = 30; total no. of lesions = 30) suitable for PTA were enrolled in the study between February 2007 and March 2008. There were 26 patients with claudication (Fontaine IIB) and 3 patients with stage IV peripheral vascular disease. In one patient, lesions in both legs were treated. No procedural or device-related complications occurred. The average degree of stenosis was 86 ± 7%. Stenosis length ranged from 8 to 88 mm. The average degree of residual stenosis was 10 ± 10%. ABI improved from 0.56 ± 0.16 to 0.92 ± 0.19 (P < 0.05). No restenosis or dissection was seen at 1-month ultrasound follow-up. Macroscopic debris was found in 27 of 30 filters of all distal protection devices used in all 29 patients. Debris particle size ranged from 90 to 2000 μm (1200 ± 640). Histological debris analysis showed platelets, erythrocytes, inflammatory cells, extracellular matrix, and cholesterol as being the major components of emboli. Additional immunochemistry showed no correlation between lesion morphology and debris components. The FilterWire EZ is easy and safe to handle. The system caused no complications. In all cases, macroscopic debris was captured. Using a distal protection device during femoropopliteal interventions has the potential to prevent migration of debris, which may be important for high-risk patients with limited distal runoff.
    CardioVascular and Interventional Radiology 12/2010; 33(6):1120-7. · 2.09 Impact Factor
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    Article: Comparison of second-generation stents for application in the superficial femoral artery: an in vitro evaluation focusing on stent design.
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    ABSTRACT: 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. 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. 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. 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.
    Journal of Endovascular Therapy 12/2010; 17(6):767-76. · 2.86 Impact Factor
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    Article: CIRSE vascular closure device registry.
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    ABSTRACT: Vascular closure devices are routinely used after many vascular interventional radiology procedures. However, there have been no major multicenter studies to assess the safety and effectiveness of the routine use of closure devices in interventional radiology. The CIRSE registry of closure devices with an anchor and a plug started in January 2009 and ended in August 2009. A total of 1,107 patients were included in the registry. Deployment success was 97.2%. Deployment failure specified to access type was 8.8% [95% confidence interval (95% CI) 5.0-14.5] for antegrade access and 1.8% (95% CI 1.1-2.9) for retrograde access (P = 0.001). There was no difference in deployment failure related to local PVD at the access site. Calcification was a reason for deployment failure in only <0.5% of patients. Postdeployment bleeding occurred in 6.4%, and most these (51.5%) could be managed with light manual compression. During follow-up, other device-related complications were reported in 1.3%: seven false aneurysms, three hematoma >5.9 cm, and two vessel occlusions. The conclusion of this registry of closure devices with an anchor and a plug is that the use of this device in interventional radiology procedures is safe, with a low incidence of serious access site complications. There seems to be no difference in complications between antegrade and retrograde access and other parameters.
    CardioVascular and Interventional Radiology 10/2010; 34(1):50-3. · 2.09 Impact Factor
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    Article: MISAGO 1: first-in-man clinical trial with Misago nitinol stent.
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    ABSTRACT: To evaluate a newly developed self-expanding Misago (Terumo Corp., Tokyo, Japan) nitinol stent with rapid exchange delivery catheter for the treatment of stenotic or occluded superficial femoral (SF) or popliteal arteries. MISAGO 1 clinical trial enrolled 55 patients undergoing percutaneous intervention of totally occluded or stenotic lesions in SF or popliteal arteries treated with the implantation of 81 stents in five centres across Europe. Primary endpoint was restenosis rate at six months assessed by duplex sonography. Patients (67% male) were 68+/-9 years old, 60% were smokers and 31% had diabetes. Clinical symptoms of ischaemia were present in all patients. Average lesion length was 85+/-50 mm, 64% were totally occluded and 38% classified as TASC C or D. The technical success rate was 100% while the procedural success rate was 98.2% without death, MI, stroke, or major bleeding. At six months follow-up the restenosis rate was 8.5%. One patient (1.8%) died of bronchial carcinoma and two (3.6%) underwent target vessel revascularisation. Mean ankle brachial index improved from 0.70 at baseline to 0.95 at six months while walking capacity on treadmill test improved with an average of 147 m. Rutherford index at six months demonstrated improvement of 72%, without any patients having symptom deterioration. One case of stent fracture was observed. The results from this first-in-man study indicate good safety and short to medium term efficacy profile of the Misago nitinol stent.
    EuroIntervention: journal of EuroPCR in collaboration with the Working Group on Interventional Cardiology of the European Society of Cardiology 01/2010; 5(6):687-91. · 3.29 Impact Factor
  • Article: Percutaneous intraluminal recanalization of long, chronic superficial femoral and popliteal occlusions using the Frontrunner XP CTO device: a single-center experience.
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    ABSTRACT: 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.
    CardioVascular and Interventional Radiology 09/2009; 33(1):25-33. · 2.09 Impact Factor
  • Article: Total percutaneous endovascular aneurysm repair with the dual 6-F Perclose-AT preclosing technique: a case-control study.
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    ABSTRACT: To determine the safety and efficacy of total percutaneous access closure for endovascular aortic aneurysm repair with a suture-mediated preclosing technique. One hundred thirty-two femoral access sites in 70 patients who underwent endovascular aortic aneurysm repair were closed percutaneously with off-label use of two F-6 Perclose AT devices preapplied at a 90 degrees angle. Femoral access sizes ranged from 12 to 24 F. Technical success, complications, and procedure and access closure times were evaluated. Follow-up with computed tomography and/or magnetic resonance imaging was scheduled at 1-4 days and 3, 6, and 12 months and used to obtain groin hematoma and scar severity scores (grades 1-3). Data were compared with those from a cohort of 67 patients who underwent endovascular aortic aneurysm repair with surgical femoral cutdown. Technical success was achieved with the preclosing technique in 127 of the 132 arteries (96.2%). Two to four closure devices were used per groin. Five technical failures were managed intraoperatively with surgical suture. There was no access-related mortality and no late groin complications. The mean procedure duration was 91 minutes +/- 32, and the mean access closure time was 12 minutes +/- 9. For surgical management, the mean procedure time was 153 minutes +/- 112 (P < .05), and the mean closure time was 12 minutes +/- 13 (not statistically significant). Hematoma severity score at 1-4 days was 1.8 for total percutaneous endovascular aneurysm repair and 2.1 for surgical closure. Scar severity scores at 3, 6, and 12 months were 1.1, 1.0, and 1.0 for total percutaneous endovascular aneurysm repair and 2.4, 2.4, and 2.3 for surgical management, respectively. Total percutaneous endovascular aneurysm repair with a dual 6-F-Perclose preclosing technique is safe and effective. Compared with femoral cutdown, there are fewer late groin complications and scar tissue formation is less severe.
    Journal of vascular and interventional radiology: JVIR 08/2009; 20(10):1292-8. · 1.81 Impact Factor
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    Article: Nitinol stent implantation in long superficial femoral artery lesions: 12-month results of the DURABILITY I study.
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    ABSTRACT: To evaluate the long-term efficacy and integrity of the PROTEGE EverFlex stent in superficial femoral artery (SFA) lesions in symptomatic patients with peripheral artery disease (PAD). A prospective, multicenter, nonrandomized study enrolled 151 subjects (111 men; mean age 67.8 years, range 42-93) undergoing percutaneous treatment of de novo, restenotic, or reoccluded SFA lesions between August 11, 2006, and June 26, 2007. Subjects were scheduled to receive a single stent and be evaluated through 12 months following the implant procedure. Occlusions were present in 40% of the patients. Mean lesion length was 96.4 mm (range 10-150). A total of 161 stents (158 EverFlex) were implanted in the 151 patients: single stents in 93.4% (141/151) and a second stent in 6.6% (10/151). One-year follow-up information was available for 88.7% (134/151) of the study participants; of the remaining 17 subjects, 6 subjects withdrew from the study, 2 were lost to follow-up, and 9 died. Freedom from restenosis data were available for 99.3% (133/134) of the subjects who completed a 12-month follow-up visit. The mean Rutherford classification fell from 2.8+/-0.8 (range 1-5) at baseline to 0.6+/-1.1 (range 0-5) at 12 months. The mean ankle-brachial index rose from 0.6+/-0.2 (range 0-1.4) at baseline to 0.9+/-0.2 (range 0-1.2) at 12 months. The rates for freedom from >50% restenosis at 6 and 12 months were 91.3% (95% CI 84.9% to 95.2%) and 72.2% (95% CI 63.8% to 79.6%), respectively. The freedom from target lesion revascularization rate at 12 months was 79.1% (95% CI 71.2% to 85.6%). The 1-year stent fracture rate was 8.1% (95% CI 4.0% to 14.4%). The high freedom from >50% restenosis and low fracture rate at 12 months suggests that the PROTEGE EverFlex stent offers a safe and acceptably efficacious means of treating SFA lesions in symptomatic subjects with PAD.
    Journal of Endovascular Therapy 06/2009; 16(3):261-9. · 2.86 Impact Factor
  • Article: Reduction of cerebral embolization in carotid angioplasty: an in-vitro experiment comparing 2 cerebral protection devices.
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    ABSTRACT: To evaluate the efficiency of 2 distal filtration devices designed for cerebral protection during carotid angioplasty in an in-vitro bench-top model. 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. 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). 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.
    Journal of Endovascular Therapy 05/2009; 16(2):161-7. · 2.86 Impact Factor
  • Article: Comparison of carotid stents: an in-vitro experiment focusing on stent design.
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    ABSTRACT: 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. 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. 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. 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.
    Journal of Endovascular Therapy 05/2009; 16(2):168-77. · 2.86 Impact Factor
  • Article: Embolic protection devices for peripheral application: wasteful or useful?
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    ABSTRACT: 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.
    Journal of Endovascular Therapy 02/2009; 16 Suppl 1:I163-9. · 2.86 Impact Factor
  • Article: Nitinol Stent Implantation in Long Superficial Femoral Artery Lesions: 12Month Results of the DURABILITY I Study
    Journal of Endovascular Therapy 01/2009; 16(3):261-269. · 2.86 Impact Factor
  • Article: Retrospective study of rapid-exchange monorail versus over-the-wire technique for femoropopliteal angioplasty.
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    ABSTRACT: The purpose of this study was to compare procedural outcome of rapid-exchange (RX) monorail versus conventional over-the-wire (OTW) technique for femoropopliteal angioplasty. Demographic data, procedure details, angioplasty success, and complications of 328 consecutive percutaneous transluminal angioplasties (PTAs) were collected from a prospective database and retrospectively analyzed. Procedure details included duration of fluoroscopy, area-dose product, amount of contrast agent, sheath sizes, access route, length of stenosis, presence of total occlusion, technical and anatomical success (residual stenosis < 30% in the absence of complications), need for bail-out stenting, and periprocedural complications. The RX technique alone was used in 102 of 328 cases (31%); the OTW technique, in 226 of 328 of cases (68%). Technical success was 98% for the RX versus 95.4% for the OTW technique (p = 0.2). A significantly greater number of stents had to be implanted due to angioplasty failure when the OTW technique was used (RX, 5.9%; OTW, 13.7%; p = 0.04). There were no significant differences in fluoroscopy time, dose-area product, or amount of contrast medium used. The RX system facilitated the use of smaller sheath sizes (5 Fr = 38% and 6 Fr = 59% for RX versus 5 Fr = 16.8% and > or = 6 Fr = 82.5% for OTW) but showed only a tendency toward lower overall complication rates (16.6% [17/102] in the RX group versus 19.9% [45/226] in the OTW group; p = 0.09). There was no effect on length of hospitalization. RX monorail systems were not associated with higher procedural costs when compared to conventional OTW technique. We conclude that RX monorail systems seem to enhance the technical success of femoropopliteal angioplasty. Although smaller sheath sizes can be used due to the lower profile of the RX systems, there is only a tendency toward lower complication rates.
    CardioVascular and Interventional Radiology 09/2007; 31(5):854-9. · 2.09 Impact Factor
  • Article: [Endovascular treatment of atherosclerotic arterial stenoses and occlusions of the supraaortic arteries: mid-term results from a single center analysis].
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    ABSTRACT: To determine mid-term patency rates after endovascular treatment of supraaortic atherosclerotic arterial stenoses and occlusions using percutaneous transluminal angioplasty (PTA) and stent placement. 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. 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. Endovascular treatment of atherosclerotic obstructive disease in brachial and cephalic arteries is a safe procedure showing promising mid-term patency rates.
    Rontgenpraxis 01/2007; 56(4):119-28.
  • Article: Influence of various cell-detachment solutions on endothelial cells after catheter abrasion for prosthesis colonization prior to implantation.
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    ABSTRACT: We (1) evaluated the effectiveness of different media on the detachment of endothelial cells (ECs) from a catheter brush (Cragg thrombolytic catheter system) that was previously used for endothelial cell abrasion in 10 cm human umbilical vein (HUV) segments; (2) tested the practicability of endovascular catheter brush abrasion followed by EC detachment from the catheter brush, in vitro culture of harvested ECs, and finally endothelialization of a prosthesis; and (3) analyzed the defect created by the catheter brush in HUV segments after endovascular catheter abrasion. Best results in detachment of ECs from the catheter brush were obtained with a mixture of phosphate-buffered saline + 1% human albumin. EC vitality was time-dependent in the collected HUV segments postdelivery. Harvested EC viability decreased from (26.28 +/- 5.76)% (0-3 h postdelivery) to (17.29 +/- 4.56)% (after 4-8 h). ECs were easily cultured ex vivo within 2-3 weeks; seeded on nitinol stents, they grew to confluency and formed a monolayer on the stent surface (determined by scanning electron microscopy - SEM). Histological and SEM analysis of HUV segments that had undergone previous catheter brush abrasion revealed slight disruption of the intima but intact subintimal layers. Our findings indicate an advantageous method of capturing and culturing primary ECs for gene therapy or for the analysis and diagnosis of certain blood vessel diseases, especially in cases in which endovascular intervention is performed anyway. Moreover, and of high relevance to the biomaterial field, theoretically the procedure could be used to endothelialze a prosthesis ex vivo for implantation into the patient from whom the ECs were harvested, to reduce the inherent thrombogenicity of the prosthesis.
    Journal of Biomedical Materials Research Part A 09/2006; 78(2):399-406. · 2.63 Impact Factor
  • Article: Treatment of acute pulmonary embolism: local effects of three hydrodynamic thrombectomy devices in an ex vivo porcine model.
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    ABSTRACT: To report an ex vivo study on the local effects of hydrodynamic thrombectomy for the treatment of acute pulmonary embolism (off-label use). Three devices (6-F AngioJet Xpeedior and 6-F and 8-F Oasis) were used for hydrodynamic thrombectomy inside the arteries of 24 inflated and perfused porcine lung explants. Each system was used at multiple positions inside 4 intact and 4 embolized lungs in vessels measuring 2 to 4 mm, 4 to 6 mm, 6 to 8 mm, and 8 to 10 mm. Angiograms prior to, during, and after catheter positioning and system operation were used to detect arterial wall trauma and to measure local clot removal per 30-second cycle. A total of 21 vessel wall samples were subjected to scanning electron microscopy (SEM) to evaluate non-perforating lesions. All systems were able to remove clot material. The average recanalized vessel length normalized to 30 seconds for vessel diameters of 2 to 4 and 8 to 10 mm, respectively, was 1.17 and 1.75 cm (AngioJet), 0.97 and 0.25 cm (6-F Oasis), and 2.2 and 1.05 cm (8-F Oasis). Perforations occurred during positioning of the 6-F Oasis (4/78 maneuvers) and 8-F Oasis (13/60), but not the AngioJet (0/89); perforations were also seen during system operation (AngioJet: 21/89 activations, 6-F Oasis: 4/78, and 8-F Oasis: 9/60; all lesions inside vessels <6 mm in diameter). SEM showed 35 lesions, 14 with perforation (contrast extravasation) and 21 without perforation (induced by the tip of the guidewire). The AngioJet was most efficient in clot removal, followed by the 8-F Oasis. The 6-F Oasis was least efficient, but had fewest complications. According to these experiments, the tested hydrodynamic thrombectomy devices may cause perforations in vessels <6 mm in diameter. Changes in catheter design to reduce system-specific complication rates or to improve the efficacy of clot removal are warranted.
    Journal of Endovascular Therapy 08/2006; 13(4):549-60. · 2.86 Impact Factor
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    Article: Stent-Protected Carotid Angioplasty Using a Membrane Stent: A Comparative Cadaver Study.
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    ABSTRACT: PURPOSE: To evaluate the performance of a prototype membrane stent, MembraX, in the prevention of acute and late embolization and to quantify particle embolization during carotid stent placement in human carotid explants in a proof of concept study. METHODS: Thirty human carotid cadaveric explants (mild stenoses 0-29%, n = 23; moderate stenoses 30-69%, n = 3; severe stenoses 70-99%, n = 2) that included the common, internal and external carotid arteries were integrated into a pulsatile-flow model. Three groups were formed according to the age of the donors (mean 58.8 years; sample SD 15.99 years) and randomized to three test groups: (I) MembraX, n = 9; (II) Xpert bare stent, n = 10; (III) Xpert bare stent with Emboshield protection device, n = 9. Emboli liberated during stent deployment (step A), post-dilatation (step B), and late embolization (step C) were measured in 100 mum effluent filters. When the Emboshield was used, embolus penetration was measured during placement (step D) and retrieval (step E). Late embolization was simulated by compressing the area of the stented vessel five times. RESULTS: Absolute numbers of particles (median; >100 mum) caught in the effluent filter were: (I) MembraX: A = 7, B = 9, C = 3; (II) bare stent: A = 6.5, B = 6, C = 4.5; (III) bare stent and Emboshield: A = 7, B = 7, C.=.5, D = 8, E = 10. The data showed no statistical differences according to whether embolic load was analyzed by weight or mean particle size. When summing all procedural steps, the Emboshield caused the greatest load by weight (p = 0.011) and the largest number (p = 0.054) of particles. CONCLUSIONS: On the basis of these limited data neither a membrane stent nor a protection device showed significant advantages during ex vivo carotid angioplasty. However, the membrane stent seems to have the potential for reducing the emboli responsible for supposed late embolization, whereas more emboli were observed when using a protection device. Further studies are necessary and warranted.
    CardioVascular and Interventional Radiology 05/2006; · 2.09 Impact Factor
  • Article: Endovascular repair of ruptured abdominal aortic aneurysm: feasibility and impact on early outcome.
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    ABSTRACT: Open repair of ruptured abdominal aortic aneurysms (AAAs) still has a high associated mortality rate. The impact of the introduction of endovascular treatment on the early outcomes of ruptured AAAs was examined at a single institution. The suitability of acute endovascular aneurysm repair (EVAR) in patients with ruptured AAAs was also assessed. Retrospective review was conducted in 39 consecutive patients treated for ruptured AAA from 2001 to 2004. The patients were divided into 15 who underwent open repair from 2001 to 2002 (group I) and 24 who were treated with open repair (n=13; 54%) or endovascular repair (n=11; 46%) from 2003 to 2004 (group II). Hospital charts and computed tomographic scans were reviewed to evaluate the feasibility of EVAR. Age, sex, and aneurysm size were similar between the two groups. The 30-day mortality rates were 53% in group I and 8% in group II (P=.003). Median procedure times were shorter in the patients who underwent EVAR. Intensive care unit stay and hospital stay were 22.0 days+/-29.6 and 29.7 days+/-33.8, respectively, in group I, and 5.6 days+/-4.4 and 16.1 days+/-10.9, respectively, in group II (P<.03). Eleven patients were found ineligible for EVAR as a result of an unsuitable neck (n=5) or iliac arteries (n=3) or both (n=3). No graft failure was detected during follow-up. After introduction of acute EVAR, a total of 46% of patients with ruptured AAAs were treated with the procedure. Potentially, 54% of patients could have been suitable for EVAR. Endovascular stent-graft implantation has significantly improved outcomes in ruptured AAAs and may therefore be beneficial in the overall treatment strategy in these patients.
    Journal of Vascular and Interventional Radiology 10/2005; 16(10):1309-12. · 2.08 Impact Factor