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Dive into the research topics where Alexander V. Tielbeek is active.

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Featured researches published by Alexander V. Tielbeek.


The Lancet | 2010

Vertebroplasty versus conservative treatment in acute osteoporotic vertebral compression fractures (Vertos II): an open-label randomised trial

Caroline A H Klazen; Paul N.M. Lohle; Jolanda De Vries; Frits H. Jansen; Alexander V. Tielbeek; Marion C Blonk; A. Venmans; Willem Jan van Rooij; Marinus C Schoemaker; Job R Juttmann; Tjoen H Lo; Harald J. J. Verhaar; Yolanda van der Graaf; Kaspar J. van Everdingen; Alex F Muller; Otto Elgersma; Dirk R Halkema; H. Fransen; Xavier Janssens; Erik Buskens; Willem P. Th. M. Mali

BACKGROUND Percutaneous vertebroplasty is increasingly used for treatment of pain in patients with osteoporotic vertebral compression fractures, but the efficacy, cost-effectiveness, and safety of the procedure remain uncertain. We aimed to clarify whether vertebroplasty has additional value compared with optimum pain treatment in patients with acute vertebral fractures. METHODS Patients were recruited to this open-label prospective randomised trial from the radiology departments of six hospitals in the Netherlands and Belgium. Patients were aged 50 years or older, had vertebral compression fractures on spine radiograph (minimum 15% height loss; level of fracture at Th5 or lower; bone oedema on MRI), with back pain for 6 weeks or less, and a visual analogue scale (VAS) score of 5 or more. Patients were randomly allocated to percutaneous vertebroplasty or conservative treatment by computer-generated randomisation codes with a block size of six. Masking was not possible for participants, physicians, and outcome assessors. The primary outcome was pain relief at 1 month and 1 year as measured by VAS score. Analysis was by intention to treat. This study is registered at ClinicalTrials.gov, number NCT00232466. FINDINGS Between Oct 1, 2005, and June 30, 2008, we identified 431 patients who were eligible for randomisation. 229 (53%) patients had spontaneous pain relief during assessment, and 202 patients with persistent pain were randomly allocated to treatment (101 vertebroplasty, 101 conservative treatment). Vertebroplasty resulted in greater pain relief than did conservative treatment; difference in mean VAS score between baseline and 1 month was -5·2 (95% CI -5·88 to -4·72) after vertebroplasty and -2·7 (-3·22 to -1·98) after conservative treatment, and between baseline and 1 year was -5·7 (-6·22 to -4·98) after vertebroplasty and -3·7 (-4·35 to -3·05) after conservative treatment. The difference between groups in reduction of mean VAS score from baseline was 2·6 (95% CI 1·74-3·37, p<0·0001) at 1 month and 2·0 (1·13-2·80, p<0·0001) at 1 year. No serious complications or adverse events were reported. INTERPRETATION In a subgroup of patients with acute osteoporotic vertebral compression fractures and persistent pain, percutaneous vertebroplasty is effective and safe. Pain relief after vertebroplasty is immediate, is sustained for at least a year, and is significantly greater than that achieved with conservative treatment, at an acceptable cost. FUNDING ZonMw; COOK Medical.


Circulation | 2002

Sirolimus-Eluting Stents for the Treatment of Obstructive Superficial Femoral Artery Disease Six-Month Results

Stephan H. Duda; Benjamin Pusich; Goetz Richter; Peter Landwehr; Vincent L. Oliva; Alexander V. Tielbeek; Benjamin Wiesinger; Jan Bart Hak; Hans Tielemans; Gerhard Ziemer; Ecatarina Cristea; Alexandra J. Lansky; Jean Paul Beregi

Background—Stent implantation for obstructive femoropopliteal artery disease has been associated with poor long-term outcomes. This study evaluated the effectiveness of shape memory alloy recoverable technology (SMART) nitinol self-expanding stents coated with a polymer impregnated with sirolimus (rapamycin) versus uncoated SMART stents in superficial femoral artery obstructions. Methods and Results—Thirty-six patients were recruited for this double-blind, randomized, prospective trial. All patients had chronic limb ischemia and femoral artery occlusions (57%) or stenoses (average lesion length, 85±57 mm). Patients were eligible for randomization after successful guidewire passage across the lesion. Eighteen patients received sirolimus-eluting SMART stents and 18 patients received uncoated SMART stents. The primary end point of the study was the in-stent mean percent diameter stenosis, as measured by quantitative angiography at 6 months. The in-stent mean percent diameter stenosis was 22.6% in the sirolimus-eluting stent group versus 30.9% in the uncoated stent group (P =0.294). The in-stent mean lumen diameter was significantly larger in the sirolimus-eluting stent group (4.95 mm versus 4.31 mm in the uncoated stent group;P =0.047). No serious adverse events (death or prolonged hospitalization) were reported. Conclusions—The use of sirolimus-eluting SMART stents for superficial femoral artery occlusion is feasible, with a trend toward reducing late loss compared with uncoated stents. The coated stent also proved to be safe and was not associated with any serious adverse events.


Journal of Endovascular Therapy | 2006

Drug-Eluting and Bare Nitinol Stents for the Treatment of Atherosclerotic Lesions in the Superficial Femoral Artery: Long-Term Results from the SIROCCO Trial

Stephan H. Duda; Marc Bosiers; Johannes Lammer; Dierk Scheinert; Thomas Zeller; Vincent L. Oliva; Alexander V. Tielbeek; John Lennon Anderson; Benjamin Wiesinger; Gunnar Tepe; Alexandra J. Lansky; Michael R. Jaff; Catharina Mudde; Hans Tielemans; Jean-Paul Beregi

Purpose: To review clinical outcomes of patients with chronic limb ischemia and TASC type C lesions treated with sirolimus-eluting versus bare SMART nitinol self-expanding stents. Methods: Data were obtained from a randomized, multicenter, double-blinded study conducted in 2 phases. All 93 patients had chronic limb ischemia and superficial femoral artery (SFA) occlusions or stenoses (average lesion length 8.3 cm). In total, 47 patients (31 men; mean age 66.3±9.1 years, range 50–84) received the sirolimus-eluting SMART stent and 46 patients (36 men; mean age 65.9 ± 10.8 years, range 38–83) received a bare SMART nitinol stent. Both groups were followed for a mean 24 months. Results: Both the sirolimus-eluting and the bare SMART stents were effective in revascularizing the diseased SFA and in sustaining freedom from restenosis. For both types of stents, improvements in ankle-brachial indices (ABI) and symptoms of claudication were maintained over 24 months (median 24-month ABI 0.96 for the sirolimus group versus 0.87 for the bare stent group, p>0.05). At 24 months, the restenosis rate in the sirolimus group was 22.9% versus 21.1% in the bare stent group (p>0.05). The cumulative in-stent restenosis rates according to duplex ultrasound were 4.7%, 9.0%, 15.6%, and 21.9%, respectively, at 6, 9, 18, and 24 months; the rates did not differ significantly between the treatment groups. The TLR rate for the sirolimus group was 6% and for the bare stent group 13%; the TVR rates were somewhat higher: 13% and 22%, respectively. Mortality rates did not differ significantly between the groups. Conclusion: These data demonstrate that the sirolimus-eluting and the bare SMART stent are effective, safe, and free from restenosis in a majority of patients for up to 24 months. Because the restenosis rate in the bare stent group is unexpectedly low, no significant difference could be found between the sirolimus-eluting and the bare SMART stents.


Journal of Vascular and Interventional Radiology | 2005

Sirolimus-Eluting versus Bare Nitinol Stent for Obstructive Superficial Femoral Artery Disease: The SIROCCO II Trial

Stephan H. Duda; Marc Bosiers; Johannes Lammer; Dierk Scheinert; Thomas Zeller; Alexander V. Tielbeek; John Lennon Anderson; Benjamin Wiesinger; Gunnar Tepe; Alexandra J. Lansky; Catharina Mudde; Hans Tielemans; Jean Paul Beregi

PURPOSE To investigate further the safety and efficacy of the sirolimus-eluting S. M.A.R.T. Nitinol Self-expanding Stent by comparison with a bare stent in superficial femoral artery (SFA) obstructions. MATERIALS AND METHODS This randomized, double-blind study involved 57 patients (29 in the sirolimus-eluting stent group and 28 in the bare stent group) with chronic limb ischemia and SFA occlusions (66.7%) or stenoses (average lesion length, 81.5 mm +/- 41.2). Stent implantation followed standard interventional techniques and a maximum of two stents could be implanted. The primary endpoint was the in-stent mean lumen diameter at 6 months as determined by quantitative angiography. RESULTS Both stent types were effective in revascularizing the diseased SFA and allowing sustained patency for at least 6 months. There was no statistically significant difference between treatment groups in the in-stent mean lumen diameter at 6 months (4.94 mm +/- 0.69 and 4.76 mm +/- 0.54 mm for sirolimus-eluting and bare stent groups, respectively; P = .31). Although the diameter of the target lesion tended to be larger and percent stenosis tended to be lower with the sirolimus-eluting stent, there were no statistically significant differences between treatments in terms of any of the variables. The mean late loss values were 0.38 mm +/- 0.64 and 0.68 mm +/- 0.97 for the sirolimus-eluting stent group and the bare stent group, respectively (P = .20). The binary restenosis rates, with a cutoff of 50% at 6 months, were zero in the sirolimus-eluting stent group and 7.7% in the bare stent group (P = .49). Clinical outcomes matched angiographic outcomes with improvements in ankle-brachial index and symptoms of claudication. There was no significant difference between treatments in terms of adverse events. CONCLUSION Although there is a trend for greater efficacy in the sirolimus-eluting stent group, there were no statistically significant differences in any of the variables.


CardioVascular and Interventional Radiology | 1997

Balloon angioplasty combined with primary stenting versus balloon angioplasty alone in femoropopliteal obstructions: A comparative randomized study.

Dammis Vroegindeweij; Louwerens D. Vos; Alexander V. Tielbeek; Jacob Buth; Harrie C. M. van den Bosch

AbstractPurpose: To evaluate whether balloon angioplasty combined with stenting (ST) of symptomatic femoropopliteal disease would provide better results compared with balloon angioplasty alone (BA). Methods: Fifty-one patients were randomized between ST (24 patients) and BA (27 patients). Follow-up comprised clinical and hemodynamic assessment and color-flow duplex ultrasound examinations. Results: Residual stenosis (≥ 30% diameter reduction) occurred in three BA patients, but not in the ST patients. By life-table analysis the cumulative rate of clinical and hemodynamic success after 1 year with ST was 74% (SE 9%) and for those with BA 85% (SE 7%) (p= 0.25). The primary patency at 1 year assessed by color-flow duplex ultrasound was 62% (SE 9%) for ST-treated patients and 74% (SE 8%) for BA patients (p= 0.22). Occlusion occurred in five ST patients (21%) compared with two BA patients (7%). Conclusion: ST does not improve clinical and hemodynamic outcome compared with BA. Moreover, the occlusion rate in ST-treated patients is higher.


Journal of Endovascular Therapy | 2002

Emergency treatment of symptomatic or ruptured abdominal aortic aneurysms: the role of endovascular repair.

Neval Yilmaz; Noud Peppelenbosch; Philippe W.M. Cuypers; Alexander V. Tielbeek; Lucien E. M. Duijm; Jacob Buth

Purpose: To report the initial experience with endovascular aortic repair (EVAR) in patients with ruptured or symptomatic abdominal aortic aneurysms (AAA) and to compare the results with conventional open surgery. Methods: Between May 1999 and December 2001, 24 patients (21 men; mean age 75 years, range 56–89) with ruptured or symptomatic AAA underwent EVAR using a specially designed aortomonoiliac endograft. Six patients were selected based on device and operator availability; the subsequent 18 patients were treated under a modified management protocol that offered stent-graft repair to all symptomatic AAA patients. The results of this new treatment protocol were analyzed on an intention-to-treat basis for the last 8 months of the study. The 30-day outcomes in all patients treated with emergency EVAR were compared with 40 consecutive, contemporaneous patients undergoing open surgery for symptomatic or ruptured AAA. Results: No early conversions to open surgery were performed. Significantly decreased operative blood loss and intensive care stay (p<0.05 for both) were observed in EVAR patients. The mortality rate for EVAR patients was 17% compared to 32% in conventionally treated patients (NS). Among patients with ruptured AAA, the 30-day mortality rates were 24% (4/17) and 41% (12/29) for EVAR and open surgery, respectively (NS). Of 26 unselected patients who were treated prospectively under the modified protocol, the majority (81%, 21/26) had anatomy suitable for endovascular repair; however, only 18 (69%) underwent EVAR owing to a short infrarenal neck (n=2) or device/operator unavailability (n=6). Conclusions: EVAR is a feasible treatment in the majority of patients with ruptured or symptomatic AAA. The 30-day mortality appears to be similar between conventionally treated patients and those undergoing endovascular repair.


Journal of Endovascular Surgery | 1998

Combined approach to stent-graft treatment of an aortic arch aneurysm.

Jacob Buth; Olaf Penn; Alexander V. Tielbeek; Marijke Mersman

Purpose: To report the first use of dual brachiocephalic vessel transposition from the aortic arch prior to endovascular exclusion of an arch aneurysm. Methods and Results: Patch graft repair of a saccular aortic arch aneurysm in a 74-year-old woman failed to exclude the lesion, resulting in aneurysm enlargement. Because the patient was debilitated, a combined open and endovascular procedure was performed in which the common carotid and subclavian arteries were transposed prior to successful insertion of a Vanguard aortic stent-graft to exclude the aneurysm. Imaging 1 and 6 months after the combined procedure demonstrated complete thrombosis of the aneurysm. Conclusions: Transposition from the aortic arch of one or more brachiocephalic vessels may allow stent-graft exclusion of aortic arch aneurysms. However, the durability of thoracic aortic endografts must be ascertained before the indications for their use are expanded.


Trials | 2007

VERTOS II: Percutaneous vertebroplasty versus conservative therapy in patients with painful osteoporotic vertebral compression fractures; rationale, objectives and design of a multicenter randomized controlled trial

Cah Klazen; Hjj Verhaar; Leh Lampmann; Job R Juttmann; Mc Blonk; Frits H. Jansen; Alexander V. Tielbeek; Marinus C Schoemaker; Erik Buskens; Y. van der Graaf; X Janssens; H. Fransen; K.J. van Everdingen; A. Muller; WPThM Mali; P.N.M. Lohle

BackgroundThe standard care in patients with a painful osteoporotic vertebral compression fracture (VCF) is conservative therapy. Percutaneous vertebroplasty (PV), a minimally invasive technique, is gaining popularity as a new treatment option. Many prospective and retrospective studies have reported on the effectiveness and safety of PV, but no large randomized controlled trial (RCT) has been published.ObjectiveTo estimate cost-effectiveness of PV compared to conservative therapy in terms of: pain reduction, quality of life, complications, secondary fractures and mortality.Materials and methodsThe VERTOS II study is designed as a prospective, multicenter RCT. Patients with a painful VCF with bone edema on MR imaging, local back pain for 6 weeks or less, osteopenia and aged 50 years or older, after obtaining informed consent are included and randomized for PV or conservative therapy. In total 200 patients will be enrolled. Follow-up is at regular intervals during a 1-year period with standard questionnaires, addressing: clinical symptoms, pain medication, Visual Analogue Scale (VAS) score, quality of life and cost-effectiveness. Secondary fractures, necessary additional therapies and complications are recorded.ConclusionThe VERTOS II study is the first methodologically sound RCT designed to assess the cost-effectiveness of PV compared to conservative therapy in patients with an acute osteoporotic VCF.Trial registrationhttp://www.clinicaltrials.gov, NCT00232466


Journal of Vascular and Interventional Radiology | 1996

Comparison of Balloon Angioplasty and Simpson Atherectomy for Lesions in the Femoropopliteal Artery: Angiographic and Clinical Results of a Prospective Randomized Trial☆

Alexander V. Tielbeek; Dammis Vroegindeweij; Jacob Buth; Guido H.M. Landman

PURPOSE This study involves a prospective randomized trial comparing clinical and angiographic results of balloon angioplasty (BA) and Simpson directional atherectomy (DA) in patients with short lesions in the femoropopliteal artery causing symptoms of intermittent claudication. MATERIALS AND METHODS Thirty-five patients were treated with BA and 38 with DA. Procedural complications were seen in eight patients. Residual stenoses immediately after the procedure with between 30% and 50% diameter reduction (DR) were observed in three patients after BA and in five patients after DA. In all other patients, residual stenosis was less than 30% DR. Two study end-points during a 2-year follow-up were used: the angiographic occurrence of restenosis with a DR of 50% or greater or the recurrence of symptoms. RESULTS Clinical success after 2 years, according to the criteria of the Society for Vascular Surgery/International Society for Cardiovascular Surgery, was seen in 79% of the BA patients and 56% of the DA patients (P = .07). The 2-year primary angiographic patency rates were 67% in patients treated with BA and 44% in patients treated with DA (P = .06). The secondary angiographically determined patency rates were 80% and 65%, respectively (P = .15). CONCLUSION Simpson atherectomy is an interventional technique to treat arterial lesions in the femoropopliteal artery with an acceptably low complication rate. The clinical and angiographic results of DA and BA are comparable. DA should not be used to replace BA for routine treatment of short femoropopliteal lesions.


CardioVascular and Interventional Radiology | 1997

The Günther temporary inferior vena cava filter for short-term protection against pulmonary embolism

Louwerens D. Vos; Alexander V. Tielbeek; Ernst P. Bom; Harm C. Gooszen; Dammis Vroegindeweij

PurposeTo evaluate clinically the Günther temporary inferior vena cava (IVC) filter.MethodsEleven IVC filters were placed in 10 patients. Indications for filter placement were surgical pulmonary embolectomy in seven patients, pulmonary embolism in two patients, and free-floating iliofemoral thrombus in one patient. Eight filters were inserted from the right femoral approach, three filters from the left. Follow-up was by plain abdominal radiographs, cavography, and duplex ultrasound (US). Eight patients received systemic heparinization. Follow-up, during 4–60 months after filter removal was by clinical assessment, and imaging of the lungs was performed when pulmonary embolism (PE) was suspected. Patients received anticoagulation therapy for at least 6 months.ResultsTen filters were removed without complications 7–14 days (mean 10 days) after placement. One restless patient pulled the filter back into the common femoral vein, and a permanent filter was placed. In two patients a permanent filter was placed prior to removal. One patient developed sepsis, and one an infection at the insertion site. Clinically no recurrent PE developed with the filter in place or during removal. One patient had recurrent PE 7 months after filter removal.ConclusionThe Günther temporary IVC filter can be safely placed for short-term protection against PE. The use of this filter is not appropriate in agitated or immunocompromised patients.

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Jacob Buth

Radboud University Nijmegen

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Lucien E. M. Duijm

Erasmus University Medical Center

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