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Çağdaş Ünlü has a total of 184 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Haemorrhagic Safety Update of CLEAR-PATH: 30 Day and 12 Month Antiplatelet Therapy After Peripheral Angioplasty

    by Emilien C.J. Wegerif, Manon I. Generaal, Linde J. Vijn, Rutger M. van Den Bor, Peter M. van de Ven, Michiel L. Bots, Gert J. de Borst, Çağdaş Ünlü


  • Open Access

    Short-Term Outcomes of Dual Versus Single Antiplatelet Therapy Following Popliteal and Infrapopliteal Endovascular Therapy: Data From Dutch Chronic Lower Limb-Threatening Ischemia Registry (THRILLER)

    by Emilien C. J. Wegerif, Michael J. Nugteren, Isa F. van Galen, Constantijn E. V. B. Hazenberg, Michiel A. Schreve, George P. Akkersdijk, Bram Fioole, Maurice Pierie, Olaf Schouten, Daniel A. F. van Den Heuvel, et al.

    Objective: There is a lack of consensus regarding the optimal antithrombotic therapy (ATT) after popliteal and infrapopliteal (PIP) endovascular therapy (EVT). Currently, dual antiplatelet therapy (DAPT) for 3 months and single antiplatelet therapy (SAPT) are the most prescribed regimens in the Netherlands. Thus far, no randomized comparison has been performed on the optimal ATT approach. Therefore, this study compared the efficacy and safety of 3-month DAPT with SAPT following PIP EVT. Design: Retrospective analysis of prospectively collected data from a multicenter registry. Methods: The Dutch chronic lower limb-threatening ischemia registry (THRILLER) collected prospective data on patients enrolled between January 2021 and October 2023. As for ATT, only patients prescribed antiplatelet therapy (APT), were included in this analysis. The primary efficacy outcome was a composite of 3-month major adverse cardiovascular events (MACEs, ie, myocardial infarction, cerebrovascular event, cardiovascular death), major adverse limb events (MALEs, ie, major amputation, reintervention), and non-cardiovascular death. Secondary efficacy outcomes were 3-month MACE, MALE, and all-cause mortality. The primary safety outcome was major bleeding according to the ‘Thrombolysis In Myocardial Infarction’ (TIMI) classification. Descriptive statistics and Cox proportional hazard models were applied. Results: In total, 460 of 840 THRILLER patients used DAPT or SAPT as ATT and were therefore included in the analysis. Of these, 322 (70%) received DAPT and 138 (30%) received SAPT. In total, 73 (15.9%) primary efficacy outcomes were observed of which 21 (15.2%) events in the SAPT group and 52 (16.1%) events in the DAPT group. No significant differences were observed between SAPT and DAPT for the primary efficacy outcomes or any of the secondary efficacy outcomes. In both groups, one case of major bleeding was observed. Conclusion: The findings suggest that 3 months of DAPT is not superior to SAPT. A well-powered randomized trial is warranted to assess the efficacy and safety of post-procedural DAPT in chronic limb-threatening ischemia (CLTI) patients undergoing PIP EVT. Clinical Impact: This manuscript reports on the efficacy and safety outcomes of 3 months of DAPT versus SAPT, which are commonly chosen therapies following popliteal and infrapopliteal endovascular therapy. No significant difference was found between the two groups regarding major adverse cardiovascular events, all-cause death, major amputation, or major bleeding. Therefore, 3 months of DAPT does not seem superior to SAPT. These results suggest that SAPT appears to be a sufficient alternative when considering 3 months of DAPT. Further research should verify these outcomes and focus on the efficacy and safety of prolonged DAPT suppletion after endovascular therapy.

  • Open Access

    Transatlantic Delphi Consensus on the Common Iliac Artery Sealing Zone in Endovascular Aorto-Iliac Aneurysm Repair (the DECIDE Study)

    by Maria-Annette Kooijman, Mario D’ORia, Luca Bertoglio, Isabelle Van Herzeele, Ross Milner, Jean-Paul P.M. de Vries, Richte C.L. Schuurmann, Gautam Agarwal, Michele Antonello, Frederico Bastos Goncalves, et al.

    Objective: Knowledge of hostile factors and their influence on long-term seal in the iliac landing zone is limited. Currently endorsed clinical practice guidelines lack structural evidence on how the iliac landing zone should be assessed in the pre-, intra-, and postoperative phases. The goal of this study was to obtain an international, expert-based consensus on the definition of a hostile iliac landing zone, on how to size and plan stent-grafts to optimize sustainable distal seal, and on the postprocedural follow-up protocol. Methods: Delphi consensus methodology was used, involving a panel of international vascular surgeons experienced in endovascular aneurysm repair (EVAR). The first round consisted of open-ended and multiple-choice questions to explore current practices, with subsequent rounds refining statements through a 4-point Likert scale. Consensus was defined as >75% agreement or disagreement, and the analysis included stability testing and strength of consensus. Results: The study engaged 77 international vascular surgeons, reflecting diverse geographic locations and hospital affiliations. Consensus was achieved on critical preoperative planning elements for EVAR, including a clear definition for a hostile iliac landing zone. The importance of computed tomography angiography for postoperative follow-up imaging was emphasized, including evaluating distal seal length and recommending specific timing for follow-up computed tomography scans and intervention strategies for diminishing iliac seal. Conclusions: This international expert-based Delphi consensus establishes a comprehensive set of consensus-driven recommendations focused on the definition and management of hostile iliac landing zones in EVAR. The key recommendation of this study is the definition of a hostile iliac landing zone as short (24 mm), or conical (>10% diameter difference along the landing zone). Although consensus was achieved on several critical aspects, the study also reveals ongoing debates and considerations that warrant further exploration, including how to tackle diminishing seal without a type IB endoleak. Clinical Impact: This Delphi consensus introduces a standardized definition of a hostile iliac landing zone as short (24 mm), or conical (>10% diameter difference), clinicians now have a clearer framework for assessing complex anatomies. This study provides a comprehensive set of consensus-driven recommendations focused on the definition and management of hostile iliac landing zones in EVAR which gives guidance where current guidelines lack specificity, particularly for distal iliac sealing. The study also reveals ongoing debates and considerations that warrant further exploration, including how to tackle diminishing seal without a type IB endoleak.


  • Open Access

    Inter- and Intra-observer Agreement of the Peripheral Arterial Calcium Scoring System in Patients Undergoing (Infra)Popliteal Endovascular Interventions

    by Michael J. Nugteren, Çağdaş Ünlü, Morsal Samim, Hester J. Scheffer, Gert J. de Borst, Constantijn E. V. B. Hazenberg

    Purpose: Peripheral arterial calcification is an important predictor of outcomes after both conservative and endovascular treatment. Digital subtraction angiography (DSA)-based calcification scores are limited by low sensitivity and inter-observer agreement. The Peripheral Arterial Calcium Scoring System (PACSS) assesses the severity of target lesion calcification. The newly introduced modified PACSS (mPACSS) also evaluates target vessel calcification. This study aimed to assess the inter- and intra-observer reliability of PACSS and mPACSS on computed tomography angiography (CTA) in (infra)popliteal endovascular interventions. Methods: A random sample of 50 limbs from the prospective multicenter Dutch Chronic Lower Limb-Threatening Ischemia Registry (THRILLER) were included. Three experienced independent raters scored PACSS on CTA. Three months later, one blinded rater assessed the same 50 CTA scans, keeping track of assessment time. The reliability of the original 5-step PACSS, a simplified binary PACSS (0–2 vs 3–4) and the 7-step mPACSS were tested using Cohen’s and Fleiss’ kappa statistics. Results: In total, 50 limbs (mean age 70.1 ± 11.0, 29 men) with 41 popliteal and 40 infrapopliteal lesions were scored. Inter-observer agreement of PACSS and binary PACSS were moderate (κ = 0.60) and substantial (κ = 0.72), respectively, while intra-observer agreement was almost perfect in both scores (κ = 0.86). Inter- and intra-observer agreement of mPACSS were moderate (κ = 0.48) and substantial (κ = 0.77), respectively. Mean assessment time for an experienced rater was 3.43 ± 0.93 min per CTA scan. Conclusion: Both the semi-quantitative PACSS and mPACSS scores for (infra)popliteal arteries can be performed reliably on pre-operative CTA. Graphic


  • Open Access

    Comparing mechanochemical endovenous ablation using Flebogrif with endovenous laser ablation in the treatment of primary great saphenous vein incompetence: protocol for a multicentre, open-label, non-inferiority, observer-blinded, randomised controlled trial (REBORN trial)

    by Sharon Oud, Tamana Alozai, Michiel A Schreve, Michael C Mooij, Clarissa J van Vlijmen, Çağdaş Ünlü

    Introduction Endovenous laser ablation (EVLA) is associated with an excellent outcome in the treatment of great saphenous vein (GSV) incompetence. However, the use of thermal ablation requires tumescent anaesthesia and is associated with a risk of thermal damage. Mechanochemical endovenous ablation (MOCA) is a non-thermal ablation (NTA) alternative, which combines mechanical endothelial damage with the infusion of a sclerosant liquid or foam. Tumescent anaesthesia is not required. Preliminary experiences with MOCA using the Clarivein device show less intraprocedural and postprocedural pain and a faster clinical improvement compared with EVLA. Flebogrif (Balton, Poland) is a relatively new MOCA device. To determine the role of MOCA using Flebogrif, a well-designed, randomised controlled clinical trial of sufficient sample size and follow-up time is required. In this article, we provide the study protocol for the REBORN trial, aiming to demonstrate that MOCA using Flebogrif is not inferior to EVLA for the outcome of anatomical success in the treatment of GSV incompetence. Methods and analysis This multicentre, open-label, non-inferiority, observer-blinded, randomised controlled trial randomises patients who are diagnosed with GSV incompetence and aged 18–80 years between Flebogrif and EVLA. 310 patients in 3 participating centres (Northwest Clinics Alkmaar, Skin and Vein Clinic Oosterwal Alkmaar and Red Cross Hospital Beverwijk) will be included. The primary outcome is anatomical success at 12 months. Secondary outcomes are intraprocedural pain, operation time, technical success, postprocedural pain, safety, anatomical success during other follow-up moments, complications, clinical success, aesthetic result, disease-specific quality of life, reinterventions, anterior accessory saphenous vein reflux and neovascularisation. Patients will be followed up at 1 week, 1, 6, 12, 24 and 60 month(s) after treatment. Ethics and dissemination The institutional review board (Medical Ethical Review Committee of the Vrije Universiteit Medical Center) approved this study on 17 May 2021 under case number 2020.0740. Written informed consent is obtained by the coordinating investigator from all participants prior to study enrolment. After completion of the trial, the results will be submitted to an international scientific journal for peer-reviewed publication. Trial registration number Overzicht van Medisch-wetenschappelijk Onderzoek in Nederland, NL-OMON25145, previously NL9527; Centrale Commissie Mensgebonden Onderzoek, NL74491.029.20.


  • Duplex Ultrasound Surveillance After Femoropopliteal Endovascular Treatment for Peripheral Arterial Disease: A Systematic Review and Narrative Synthesis

    by Nathalie C.C. Hoitz, Michael J. Nugteren, Eline Huizing, Bram Fioole, Barend M.E. Mees, Gert J. de Borst, Çağdaş Ünlü


  • Open Access

    The Dutch chronic lower limb-threatening ischemia registry (THRILLER): A study protocol for popliteal and infrapopliteal endovascular interventions

    by Michael J. Nugteren, Constantijn E. V. B. Hazenberg, George P. Akkersdijk, Olaf J. Bakker, Maarten K. Dinkelman, Bram Fioole, Daniel A. F. van Den Heuvel, Jan M. M. Heyligers, Jan-Willem Hinnen, Maurice Pierie, et al.

    Introduction: Chronic limb-threatening ischemia (CLTI) is the end stage of peripheral arterial disease (PAD) and is associated with high amputation rates, mortality and disease-related health care costs. In infrapopliteal arterial disease (IPAD), endovascular revascularization should be considered for the majority of anatomical and clinical subgroups of CLTI. However, a gap of high-quality evidence exists in this field. The aim of the Dutch Chronic Lower Limb-Threatening Ischemia Registry (THRILLER) is to collect real world data on popliteal and infrapopliteal endovascular interventions. Methods: THRILLER is a clinician-driven, prospective, multicenter, observational registry including all consecutive patients that undergo a popliteal or infrapopliteal endovascular intervention in seven Dutch hospitals. We estimate that THRILLER will include 400–500 interventions annually. Standardized follow-up visits with wound monitoring, toe pressure measurement and duplex ultrasonography will be scheduled at 6–8 weeks and 12 months after the intervention. The independent primary endpoints are primary patency, limb salvage and amputation free survival. Patients must give informed consent before participation and will be included according to predefined reporting standards. A data log of patients who meet the inclusion criteria but are not included in the registry will be maintained. We intend to conduct the first interim analysis two years after the start of inclusion. The results will be published in a scientific journal. Discussion: Despite innovations in medical therapy and revascularization techniques, patients with CLTI undergoing endovascular revascularization still have a moderate prognosis. Previous prospective cohort studies were hampered by small sample sizes or heterogeneous reporting. Randomized controlled trials (RCTs) have high costs, potential conflicts of interest and give a limited reflection of daily practice. THRILLER aims to provide the largest prospective well phenotyped up-to-date dataset on treatment outcomes in CLTI patients to answer multiple underexplored research questions regarding diagnostics, medication, patient selection, treatment strategies and post intervention follow-up.


  • Open Access

    Validation of an ex vivo Flow Model Including Magnetic Resonance Imaging to Study the Effects of Endovascular Treatments on the Arterial Wall

    by Raúl Devia Rodriguez, Eline Huizing, Çağdaş Ünlü, Frank F.J. Simonis, Reinoud P.H. Bokkers, Jean-Paul P.M. de Vries, Richte C.L. Schuurmann, Dalibor Nakladal, Hendrik Buikema, Jan-Luuk Hillebrands, et al.

    Endovascular revascularization is the preferred treatment for peripheral arterial disease. Restenosis often occurs as a response to procedure-induced arterial damage. Reducing vascular injury during endovascular revascularization may improve its success rate. This study developed and validated an ex vivo flow model using porcine iliac arteries, obtained from a local abattoir. Twenty arteries (of 10 pigs) were equally allocated to two groups: a mock-treated control group and an endovascular intervention group. Arteries of both groups were perfused with porcine blood for 9 min, including 3 min of balloon angioplasty in the intervention group. Vessel injury was assessed by calculating the presence of endothelial cell denudation, vasomotor function, and histopathological analysis. MR imaging displayed balloon positioning and inflation. Endothelial cell staining showed 76% of denudation after ballooning compared to 6% in the control group (p < 0.001). This was confirmed by histopathological analysis, showing a significantly reduced endothelial nuclei count after ballooning compared to the controls (median: 22 vs. 37 nuclei/mm, p = 0.022). In the intervention group, vasoconstriction and endothelium-dependent relaxation were significantly reduced (p < 0.05).We present an ex vivo flow model to test the effects of endovascular therapy on the vessel’s wall morphology, endothelial denudation, and endothelial-dependent vasomotor function under physiological conditions. Additionally, it allows the future testing of human arterial tissue.