Koray Aykut

Izmir University, Ismir, İzmir, Turkey

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Publications (30)21.32 Total impact


  • No preview · Article · Mar 2015 · The American Journal of Cardiology

  • No preview · Article · Jan 2015 · World Journal of Cardiovascular Diseases
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    ABSTRACT: Bisphosphonates, including alendronate, are widely used for the treatment of osteoporosis, hypercalcemia and bone metastasis associated with cancer. However, recent evidence has demonstrated anti-atherosclerotic effects of bisphosphonates in animal models and atherosclerotic patients. Besides, some studies have shown that bisphosphonates change calcium homeostasis in cardiomyocytes and interfere L-type calcium channels in vascular smooth muscle cells. Therefore, in the present study it was aimed to investigate the effects of alendronate on contractile responses and ATP-sensitive potassium channels in vitro in human Left Internal Mammary Artery (LIMA). Human LIMA rings were placed into isolated organ chambers. After resting period, rings were kept for an hour in incubation medium which contains alendronate (10-6 M) or not (control) and responses of the rings to the contractile agents were examined. The incubation of two rings was performed in the presence of glibenclamide which is ATP-sensitive potassium channel blocker (10-6 M). Maximum contractile responses of LIMA rings to noradrenalin and serotonin decreased in the presence of alendronate. In concomitant incubation of LIMA with alendronate and glibenclamide reversed decreased contractions to noradrenalin or serotonin caused by alendronate. However, neither alendronate nor glibenclamide changed sensitivity to noradrenaline or serotonin. The present findings point out that alendronate may change intracellular calcium dynamics in human LIMA, due to the activation of ATP-sensitive potassium channels which have an important role on cardiovascular system.
    Full-text · Article · Dec 2014 · International Journal of Pharmacology
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    ABSTRACT: Objectives: We assessed the effect of resveratrol on intimal hyperplasia and endothelial proliferation after its use for carotid artery anastomosis in rabbits. Methods: Fourteen New Zealand-type male rabbits, weighing a mean of 2-3 kg were selected randomly. Their right carotid arteries were transected and anastomosed side by side using 8/0 polypropylene. The rabbits were divided into two groups with seven in each group. While the rabbits in the first group were accepted as the Control group, the rabbits in the second group were given resveratrol (1 mg/kg/day) for 14 days intravenously. At the end of the 28th day, all the carotid artery segments that were transected and anastomosed and the left carotid arteries that did not undergo surgery were removed and evaluated histologically. Results: The results of histological evaluation were as follows: lumen diameter (P <0.001) and lumen area (P <0.05) of the Resveratrol group were larger than those of the Control group, intimal thickness (P <0.05) and media thickness of the Resveratrol group (P = 0.04) were thinner than those of the Control group, and intima/media ratio of the Control group was found to be greater than that of the Resveratrol group (P = 0.002). Conclusions: Resveratrol can prevent intimal hyperplasia and endothelial proliferation following surgical anastomosis.
    Full-text · Article · Sep 2014 · Interactive Cardiovascular and Thoracic Surgery
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    ABSTRACT: Patent ductus arteriosus (PDA) is commonly seen in premature infants with low birth weights (LBW). It is a condition that has high mortality and morbidity rates. Early closure of the ductus arteriosus may require surgery or medical treatment. However, the decision of first medical approach for symptomatic PDA closure is still debated. In this study, we compared the surgical and medical treatments for the closure of PDA in premature LBW infants. This study included 27 premature infants whose birth weights were lower than 1500 g, who were born in the period between 2011 and 2013 and had symptomatic PDA. Patients were separated into two groups: groups A and B. Group A included patients whose PDAs were closed with medical treatment (n = 16), and group B included patients who had undergone surgical operations for PDA closure (n = 11). There were no statistically significant differences between groups A and B when the groups were compared in terms of birth weight, gestational age, respiratory distress syndrome (RDS), necrotizing enterocolitis (NEC), sepsis, intraventricular hemorrhage (IVH), retinopathy of prematurity (ROP), and pneumothorax. Although the mortality rate was determined to be lower in group B (2 out of 11, 18.1%) than in group A (7 out of 16, 43.7%), no statistically significant difference was found between the two groups. A statistically significant increase was determined in the incidence of kidney function loss in patient group that received Ibuprofen, a medical treatment, in comparison to the patients who had surgery. In conclusion, surgery is a safe method to repair PDA in premature LBW infants. Although there is no remarkable difference between surgery and medical treatment, we suggest that a surgical approach may be used as a first choice to repair PDA considering the lower rate of mortality and morbidity and higher rate of closure compared to medical treatment.
    Preview · Article · Aug 2014 · Open Journal of Cardiovascular Surgery
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    ABSTRACT: Background: We aimed to investigate the post-procedure effect of pulsatile and non-pulsatile flow utilized in cardiopulmonary bypass on brain ischemia among patients undergoing coronary artery bypass grafting (CABG) surgery. Methods: A total of 80 patients undergoing elective CABG between April 2012 and January 2013 were separated into two groups. While pulsatile flow was implemented during cardiopulmonary bypass in 40 patients, non-pulsatile flow was used in the remaining 40 cases. Formation of new ischemic lesions in the brain was evaluated by Diffusion-weighted magnetic resonance imaging (DW-MRI), performed prior to and after the operation. Results: No statistically significant differences were found between the two groups in terms of demographic values and concomitant diseases. New focal lesions were detected in 7 of 40 patients subjected to pulsatile flow (17.5%) and in 4 of 40 cases subjected to non-pulsatile flow (10%). Although the number of new lesions detected on brain diffusion MRI in the non-pulsatile flow patient group was lower in terms of the number of patients and the number of lesions, no statistically significant differences were determined between the two groups. Conclusions: Magnetic resonance imaging evidence of brain injury were similar after pulsatil-pump and nonpulsatil-pump coronary artery bypass grafting surgery.
    No preview · Article · May 2014 · Journal of cardiovascular disease research

  • No preview · Article · Jan 2014 · World Journal of Cardiovascular Surgery

  • No preview · Article · Jan 2014
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    ABSTRACT: Objective: Chronic venous insufficiency, which has a high prevalence rate and a high expense, is an important health problem leading to an apparent decline in work-power and quality of life. Endovenous Laser Ablation (EVLA) currently gains importance in the treatment of great saphenous vein (GSV) insufficiency. The efficiency and adverse effects of EVLA with different wave-lengths are emphasized. The aim of this article is to determine the efficiency and adverse effects of EVLA with 980 nm and 1470 nm wave-lengths. Material and Methods: A total of 86 cases with grade 4 insufficient GSV and absence of deep and perforating vein insufficiencies comprised the study population. The study group was randomized into two groups; in group 1 980 nm bared-fiber, and in group 2 1470 nm radial-fiber catheter was used. The proximal and distal diameters of GSV before the intervention, and the rates of adverse effects and recanalization were determined in the first, fourth and sixth weeks after the intervention. A p value less than 0.05 was regarded as significant. Results: While the diameters of proximal and distal GSV in group 1, including 44 cases, were 6.4±0.87 mm and 5.8±0.71 mm respectively, those values were 6.7±1.72 mm and 5.9±0.62mm in group 2 which included 42 cases. At the end of the first week, the rate of hyperemia (p<0.001) and formation of bullous structures (p=0.03) were higher in group 1. At the end of the fourth week, the rate of hyperpigmentation (p=0.005) was higher in group 1. At the end of the sixth week, while the recanalization rate was lower in group 2 (p=0.058), there was no significant difference. The cumulative rate of the development of deep vein thrombosis between groups (13.6% in group 1, 2.4% in group 2) did not show any difference (p=0.110). Conclusion: The radial-fiber EVLA catheter with 1470 nm wave-length provides both higher efficiency and less adverse effects.
    Preview · Article · Jan 2014 · Turkiye Klinikleri Journal of Medical Sciences

  • No preview · Article · Jan 2014 · World Journal of Cardiovascular Surgery

  • No preview · Article · Jan 2014 · World Journal of Cardiovascular Surgery
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    ABSTRACT: In elderly patients with mild cognitive impairment, noncompliance with respiratory exercises, ineffective expectoration, reluctance in mobilization, and difficulty in learning the use of drugs such as inhalers were observed in the early postoperative period after coronary artery bypass graft surgery. It was hypothesized that respiratory complications may be more frequent in these patients, and so the postoperative respiratory complications in patients with preoperative mild cognitive impairment were compared with the postoperative respiratory complications of a control group. A prospective cohort control. A university hospital. Patients undergoing elective coronary artery bypass graft surgery. Investigators separated 48 patients>70 years old who were scheduled for elective coronary artery bypass graft surgery into two groups: patients with preoperative mild cognitive impairment (group A, n = 25) and patients with no cognitive impairment (control group; group B, n = 23). The patients' cognitive status was evaluated preoperatively by the Montreal Cognitive Assessment test. Pulmonary functions and respiratory complications were evaluated via chest x-rays and spirometry tests preoperatively and postoperatively. A significant difference was observed between the groups, particularly with regard to atelectasis and prolonged ventilation (p<0.001 andp<0.05). No significant impairment was observed in the spirometry tests of the control group. However, a significant deterioration was observed in the postoperative spirometry tests of patients with preoperative mild cognitive impairment. This study suggested that mild cognitive impairment was associated with pulmonary complications after coronary artery bypass graft surgery.
    No preview · Article · Aug 2013 · Journal of cardiothoracic and vascular anesthesia
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    ABSTRACT: PurposeThe guiding role of the Fogarty catheter was investigated among patients suffering from limb ischemia due to acute femoropopliteal bypass graft occlusion.MethodsA total of 27 patients with a history of femoropopliteal bypass operation who was admitted with acute limb ischemia were enrolled in this retrospective study. In cases in which the Fogarty catheter could not be passed through the popliteal anastomosis, the popliteal region was explored and a new bypass or patch plasty was performed for the distal anastomosis. The cases in which the blood circulation was observed in the graft, but in which the Fogarty catheter balloon was stuck in the native vessels on the proximal and distal side of the graft and the balloon could be withdrawn by deflation, were referred to conventional angiography. The stenosis observed in native vessels was managed by endovascular stent grafting and/or balloon dilatation.FindingsGraft patency was achieved in all patients. In 11 patients, conventional angiography was implemented following embolectomy. In these patients, all the occlusions found as significant on angiography were removed by percutaneous transluminal angioplasty.Conclusion Effective use of Fogarty catheter is safe in acute femoropopliteal bypass graft occlusions and in particular, in the planning of further treatment following thrombectomy.
    No preview · Article · Jul 2013 · Vascular
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    ABSTRACT: In this prospective study, we aimed to compare the effect of pulsatile and non-pulsatile flow on the cognitive functions in patients undergoing coronary artery bypass surgery. Patients scheduled for their first coronary artery bypass surgery (n = 148) were randomly assigned to the pulsatile flow group (Group A, n = 75) or non-pulsatil group (Group B, n = 73). Cognitive performance was assessed with (MoCA) montreal cognitive assessment test performed by psychologists before coronary artery bypass surgery and 1 month after the operation. Mild cognitive impairment was seen in 12 (16%) patients and serious cognitive impairment was seen in 1 (1.33%) patient in the pulsatile flow group. In the other group, mild cognitive impairment was detected in 23 (31.50%) patients and serious cognitive decline was found in 3 (4.10%) patients. Mean MoCA scores were 25.86 ± 2.62 in group A and 22.12 ± 2.20 in group B. The difference between two groups was statistically significant (P = 0.041). We suggest that pulsatile flow has beneficial effects to decrease cognitive dysfunction in patients undergoing on-pump coronary artery bypass surgery.
    No preview · Article · Jun 2013 · Journal of cardiovascular disease research
  • Ahmet C Ozdemir · Koray Aykut
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    ABSTRACT: Objective: To elucidate the effect of bone wax on postoperative bleeding, infection and wound healing.Methods: This study included two independent groups, consisting of 94 patients who were treated with bone wax and 90 patients who received nothing after median sternotomy and just before sternal closure. Demographic and postoperative data were recorded. Both groups were compared with respect to the amount of postoperative drainage, blood transfusion requirement, re-exploration because of bleeding, and mortality rates.Results: Demographic measurements did not differ between the groups. In the first two months of the postoperative period, mediastinitis was not seen in any of the patients in both groups. Superficial wound infection was detected in six patients (6.4%) in Group A. Eight patients (8.9%) suffered from superficial wound infection in Group B (p >0.05). In the first postoperative 24 hours, the average amount of postoperative drainage was 536.89 ml in Group A, whereas it was 529.67 ml in Group B (p >0.05). Three patients in both groups died in the early phase of the postoperative period (p >0.05).There was not any statistically significant difference between groups considering bleeding quantity, mortality, re-exploration, amount of blood used and deep sternal infection.Conclusion: Bone wax does not reduce bleeding on sternal sides. No evidence was found that application of bone wax causes deep sternal infection in patients having median sternotomy for coronary bypass surgery.
    No preview · Article · Apr 2013

  • No preview · Article · Mar 2013 · International Journal of Cardiology
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    ABSTRACT: Purpose: Intimal thickening, which results from the response to arterial damage caused by therapeutic interventions or other reasons, is usually called as neointima. Neointimal hyperplasia is a main step in the pathogenesis of late-term restenosis, which is developed after vascular interventions. Reduction in nitric oxide (NO)/cyclic guanosine monophosphate (cGMP) signaling plays a substantial role in the pathogenesis of neointima formation. Phosphodiesterase V is detected in the peripheral coronary and pulmonary vascular smooth muscle cells and in the cardiac tissue. Based on the effects of phosphodiesterase V inhibitors on vascular smooth muscle cells, in the present study, the effect of tadalafi l, a new member of phosphodiesterase V inhibitors, on neointimal hyperplasia was investigated in the rabbit carotid artery anastomosis model. Material and method: Fourteen male New Zealand white rabbits weighing between 2.5-3 kg, were used. The rabbits were randomly divided into two equal groups; tadalafi l group received oral tadalafil (2 mg/kg/day), and PBS group received sterile PBS solution (normal saline; 2 mg/kg/day) for 28 days after the surgery. The right carotid arteries of all rabbits were anastomosed in an end-to-end fashion using 8/0 polypropylene suture. The rabbits were sacrificed at the end of the postoperative period of 28 days. After sacrifi cing, fi rstly anastomosis segment on the right carotid artery and secondly a part of the left carotid artery (as control) of each rabbit were removed. Morphometric examination of tissue sections was performed under a light microscope connected to an image capture system. Results: There was a significant difference between the right and left carotid arteries in terms of intimal area and intima/media ratio both in tadalafi l and PBS groups (p <0.001 for each). Intimal area and intima/media ratio were increased in the right carotid arteries compared to the left carotid arteries (p <0.001 for each). Besides, when the right carotid arteries of both groups were compared using covariance analysis, it was observed that intimal area and intima/media ratio in the anastomosis site were signifi cantly reduced with tadalafil treatment (p <0.001). Conclusion: The present study was promising in terms of tadalafil use as a new agent for the prevention of neointimal hyperplasia, which is the leading cause of late-term graft failure in vascular surgery.
    Full-text · Article · Jan 2013

  • No preview · Article · Jan 2013
  • Koray Aykut · Murat Kaya · Unal Acıkel
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    ABSTRACT: A 32-year-old man was urgently referred to our hospital with severe tricuspid insufficiency following a car accident. The completely flail anterior leaflet, due to the rupture of the papillary muscles, was revealed by a two-dimensional transthoracic echocardiography. In the operation, we also detected a tear on the anterior leaflet and the rupture of numerous chordae tendineae of the other leaflets. Valve repair was not considered feasible, therefore the tricuspid valve was replaced with a 31 mm mechanical prosthesis. The patient's recovery from surgery was uneventful, and he was discharged on the seventh postoperative day.
    No preview · Article · Nov 2012
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    ABSTRACT: Background: Acute renal failure due to renal ischemia/reperfusion (IR) injury is a significant clinical problem in cardiovascular surgery. Reactive oxygen species and inflammation play essential roles in the pathophysiology of IR injury. Matrix metalloproteinases (MMPs) are enzymes that play important roles in inflammation and mediate extracellular matrix degradation. It is known that peroxisome proliferator-activated receptor-γ agonists have antiinflammatory and antioxidant effects. In the present study, we aimed to investigate the effects of pioglitazone, a synthetic peroxisome proliferator-activated receptor-γ agonist, on MMPs and oxidative stress in a renal IR injury model in rats. Materials and methods: Male Wistar albino rats were divided into three groups: control (n = 7), placebo (n = 7; saline/p.o.), and pioglitazone (n = 7; 5 mg/kg/day/p.o.). In the control group, a right nephrectomy was conducted without left renal IR injury. In the placebo and pioglitazone groups, pretreatments were started 3 d before operation. In both groups, left renal pedicles were clamped for 60 min and then reperfused for 60 min. Paraffinized renal sections were evaluated histopathologically. Furthermore, expressions of MMP-2, MMP-9, tissue inhibitor of metalloproteinase (TIMP)-2, superoxide dismutase 1 (SOD1), and p47-phox/p67-phox subunits of NADPH oxidase were determined by immunostaining and scoring. Results: In the placebo group, renal IR injury induced diffuse tubular necrosis and intense acute inflammation, but pioglitazone inhibited these effects. MMP-2, MMP-9, and TIMP-2 expression increased in the placebo group. However, while MMP-2 and -9 expression decreased, TIMP-2 expression did not change in the pioglitazone group. p47-phox/p67-phox expression increased in the placebo group, but SOD1 expression did not change. Pioglitazone diminished p47-phox/p67-phox expression, whereas it enhanced SOD1 expression. Conclusion: Our results suggest that pioglitazone might be helpful to reduce renal IR injury because of its antiinflammatory and antioxidant effects.
    Full-text · Article · Aug 2012 · Journal of Surgical Research