Koray Aykut

Izmir University, Ismir, İzmir, Turkey

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Publications (16)13.43 Total impact

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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.
    International Journal of Pharmacology 12/2014; 10(8):501-506. · 1.20 Impact Factor
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    ABSTRACT: We assessed the effect of resveratrol on intimal hyperplasia and endothelial proliferation after its use for carotid artery anastomosis in rabbits.
    Interactive Cardiovascular and Thoracic Surgery 09/2014; · 1.11 Impact Factor
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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.
    Open journal of cardiovascular surgery. 01/2014; 7:1-4.
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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.
    Journal of cardiothoracic and vascular anesthesia 08/2013; · 1.06 Impact Factor
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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.
    Vascular 07/2013; · 0.86 Impact Factor
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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.
    Journal of cardiovascular disease research 06/2013; 4(2):127-9.
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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.
    Annals of thoracic and cardiovascular surgery : official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia. 01/2013;
  • 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.
    Annals of thoracic and cardiovascular surgery : official journal of the Association of Thoracic and Cardiovascular Surgeons of Asia. 11/2012;
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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.
    Journal of Surgical Research 08/2012; · 2.02 Impact Factor
  • Koray Aykut, Bulent Celik, Unal Acıkel
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    ABSTRACT: We investigated the short and mid-term outcome of the transseptal approach to the mitral valve during multivalvular surgery. Within a three-year period ending in May 2010, we used the transseptal approach in performing mitral valve surgery in 62 patients. Procedures performed were: mitral valve replacement and tricuspid annuloplasty in 40 patients, both aortic and mitral valve replacement with tricuspid annuloplasty in 13 patients, mitral valve and tricuspid valve replacement in eight patients and mitral valve repair and tricuspid annuloplasty in addition to coronary artery bypass surgery in one patient. There were no complications associated with the transseptal approach. There were no conduction abnormalities, nor were there any procedure-related deaths. We conclude that use of the transseptal approach for mitral valve operations is simple and safe in patients necessitating right atriotomy for concomitant procedures. 
    Journal of Cardiac Surgery 08/2011; 26(5):472-4. · 1.35 Impact Factor
  • Koray Aykut, Bulent Celik, Unal Acıkel
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    ABSTRACT: Sternal dehiscence is a serious and potentially devastating complication after median sternotomy, especially in diabetic obese patients. The optimal technique for sternal closure is unclear in these patients. The purpose of this prospective randomized study was to compare the incidence of sternal dehiscence after prophylactic sternal weave and figure-of-eight suturing in diabetic obese patients undergoing coronary artery bypass grafting (CABG). The patients were randomly assigned to group A (figure-of-eight closure; n=75) or group B (sternal weave closure; n=75). There were 8 cases of sternal dehiscence documented: 7 in group A and 1 in group B. In group A, 5 patients had noninfectious sternal dehiscence and 2 patients underwent reoperation because of sternal dehiscence with mediastinitis. Also, 1 of the noninfected patients had deep-seated pain with a feeling of bony crepitus and needed reoperation. The other 4 patients in group A and 1 patient with noninfectious sternal dehiscence in group B were given chest binder support. Pain and bony crepitus decreased in the follow-up period of 1 year. Sternal dehiscence rates were 9.3% in group A and 1.3% in group B. Sternal dehiscence was significantly lower in group B (p<0.05). Prophylactic sternal weave closure of median sternotomy reduces morbidity from sternal dehiscence in diabetic obese patients undergoing CABG.
    The Annals of thoracic surgery 06/2011; 92(2):638-41. · 3.45 Impact Factor
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    ABSTRACT: The aim of the present study was to investigate the effect of zoledronic acid (ZA), as a matrix metalloproteinase inhibitor, on neointimal hyperplasia in rabbit carotid anastomosis model. New Zealand male rabbits were divided into two groups as placebo and treatment groups in this experimental study. After anesthesia, the right carotid artery of each rabbit was end-to-end anastomosed with an 8/0 polypropylene suture. Left carotid artery was kept as control without any operation. Placebo group (n=6) received phosphate buffered saline (PBS) (0.5mL/kg/day/s.c.) for 28 days postoperatively, whereas ZA group (n=6) received ZA (100 µg/kg/day/s.c.) for the same period. After sacrification, the anastomosed and control arteries were isolated. Morphometric and immunohistochemical examinations were performed. Statistical analyses of morphometric and immunohistochemical data were performed using two-way ANOVA and Chi-square test respectively. In PBS group, vascular injury in the anastomosed artery significantly increased the intimal area (anastomosed: 112.51±61.18 µm(2)*1000 vs. control: 22.62±4.26 µm(2)*1000, p<0.01) and intima/media index (anastomosed: 0.347±0.29 vs. control: 0.075±0.01, p<0.05) compared to control artery. ZA significantly reduced the intimal area (39.29±18.21 µm(2)*1000 , p<0.01) and intima/media index (0.112±0.07, p<0.05) compared to PBS group. Additionally, α-smooth muscle actin immunopositivity was found significantly decreased in anastomosed arteries from ZA group (ZA: 2.33±0.52 vs. PBS: 3.50±0.5, p<0.05). Moreover, intensive gelatinase (MMP-2 and MMP-9) immunoreactivities were clearly seen in anastomosed arteries compared to control arteries from PBS group. ZA apparently decreased immunopositivities for gelatinases in anastomosed arteries. ZA might be a promising agent for prevention of neointimal hyperplasia, which is the most significant cause of graft failures in late postoperative period.
    Anadolu kardiyoloji dergisi: AKD = the Anatolian journal of cardiology 02/2011; 11(2):93-100. · 0.72 Impact Factor
  • Koray Aykut, Coskun Ozdemir, Unal Acikel
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    ABSTRACT: Lymphangioma circumscriptum is an uncommon benign disorder of skin and subcutaneous tissues characterized by dilated lymphatic channels. It is an uncommon vascular tumor and it rarely becomes infected. We report a 20-year-old man who had an infected giant tumor in his left thigh. After an extensive resection and radiofrequency energy therapy, he recovered well with an acceptable cosmetic result. We followed up the patient for 2 years without any recurrence.
    Annals of Vascular Surgery 10/2010; 24(7):953.e11-2. · 0.99 Impact Factor
  • Koray Aykut, Coskun Ozdemir, Unal Acikel
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    ABSTRACT: Le lymphangiome circonscrit est une lésion bénigne rare de la peau et des tissus sous-cutanés caractérisée par des canaux lymphatiques dilatés. C’est une tumeur vasculaire rare et elle s’infecte rarement. Nous rapportons un homme de 20 ans qui avait une tumeur géante infectée de la cuisse gauche. Après une résection étendue et un traitement par radiofréquence, il a bien récupéré avec un résultat cosmétique acceptable. Nous avons suivi le patient pendant 2 ans sans récidive.
    Annales De Chirurgie Vasculaire. 01/2010; 24(7).
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    ABSTRACT: In open-heart surgery, sternal wound infection after median sternotomy is a critical complication. The intracutaneous suture is conventionally used in closing sternal incisions. In this prospective, randomized, controlled clinical trial, intracutaneous and transcutaneous suture techniques for closing the sternum were compared with respect to postoperative sternal wound infections and cosmetic results. In this study, we included 100 patients who had undergone open-heart surgery. Skin wounds were closed with intracutaneous suture in 50 patients and with transcutaneous suture in the remaining 50. Superficial or deep sternal infections that developed within 6 postoperative weeks were evaluated. Cosmetic results were similar in the 2 groups. Deep wound infections were not observed in either group. Superficial infection of postoperative sternal wounds occurred at rates of 2% (n=1) and 16% (n=8) for transcutaneous and intracutaneous techniques, respectively (P = 0.016). One patient in the transcutaneous group and 6 patients in the intracutaneous group who developed superficial sternal infections were diabetic. Although the use of the transcutaneous suture technique in closing sternal incisions of cardiac surgery patients provided no cosmetic improvement, it decreased the risk of superficial sternal infection and reduced the length of postoperative hospital stay, particularly in diabetic patients.
    Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 02/2005; 32(3):277-82. · 0.67 Impact Factor
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    ABSTRACT: In this study, the effect of iloprost on renal ischemia-reperfusion injury was investigated using an experimental rat model. Adult male Wistar rats subjected to 60 min of unilateral warm ischemia were allocated into sham (n = 4), control (n = 7) and iloprost (n = 7) groups. Iloprost was administered intravenously via the right external jugular vein at a dose of 2 ng/kg/min. Infusion started the same time as we clamped the artery of the left kidney and continued for about an hour in the early phase of reperfusion. Blood samples for biochemical parameters were drawn just before and 72 h after clamping the renal artery. Histopathological examinations of the kidney specimens were performed to detect probable changes due to reperfusion injury. Mean blood urea nitrogen and creatinine levels after 72 h were lower in the iloprost group than the control group, but the difference between these two groups was not significant. Severe (grade 2 or 3) acute tubular necrosis was detected in 86% of rats in the control group; the ratio was 57% in the iloprost group. But the difference between these two groups was not significant. Although, these findings suggest that iloprost treated rats have less injury, iloprost does not reduce ischemia-reperfusion injury in a rat model when only given during the ischemic and early reperfusion period.