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Dive into the research topics where Omer Isik is active.

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Featured researches published by Omer Isik.


The Annals of Thoracic Surgery | 2000

Midterm angiographic assessment of coronary artery bypass grafting without cardiopulmonary bypass

Suat Nail Omeroglu; Kaan Kirali; Mustafa O. Guler; Mehmet Erdem Toker; Gökhan İpek; Omer Isik; Cevat Yakut

BACKGROUND Coronary bypass surgery that provides good long-term graft patency can be performed on the beating heart as a viable alternative to conventional coronary artery bypass grafting (CABG). METHODS From September 1993 to December 1996, 696 patients underwent CABG on the beating heart at the Koşuyolu Heart and Research Hospital in Istanbul. Among them, 70 patients were chosen randomly for angiographic assessment of off-pump coronary artery bypass grafting. RESULTS The interval from operation to angiography varied from 24 to 61 months (mean, 36.1+/-10.9 months). The patency rate of left internal mammary-left anterior descending artery anastomoses was 95.59% (patency achieved in 65 of 68 patients) and of vein grafts was 47.06% (patency achieved in 16 of 34 patients) (p < 0.0001). The patency rates of grafts anastomosed to the left anterior descending artery were significantly higher than the rates of the grafts anastomosed to the other coronary arteries (95.71% versus 45.45%, p < 0.0001). Multivariate analysis showed that graft type (p < 0.0001) and hyperlipidemia (p = 0.023) were significant predictors for graft occlusion. Left ventricular function improved significantly after CABG (p = 0.04). Reintervention (using percutaneous transluminal cardiac angioplasty) and reoperation rates were 0.97% and 1.4%, respectively. CONCLUSIONS Off-pump coronary artery bypass grafting appears to produce midterm and long-term patency rates that are comparable to those of conventional techniques; that is especially true in cases of arterial conduits and of conduits anastomosed to the left anterior descending artery.


Journal of Cardiac Surgery | 2005

Surgical treatment of subaortic obstruction in adolescent and adults: long-term follow-up.

Vedat Erentug; Nilgun Bozbuga; Kaan Kirali; Deniz Göksedef; Esat Akinci; Omer Isik; Cevat Yakut

Abstract  Subaortic stenosis (SAS) is a wide spectrum of anatomical dearrangements ranging from a discrete fibrous membrane to tortuous fibrous tunnel with or without aortic annulus hypoplasia. We have reviewed 88 patients undergoing surgery for SAS over a 15‐year period. There were 47 male and 41 female patients with a mean age of 19.8 ± 10.6 years (range 11 to 39). Fifty‐eight patients had discrete subaortic membrane, and 30 patients had diffuse tunnel subvalvular stenosis. The mean systolic pressure gradients were found to be 86.5 ± 31.4 mmHg (range 48 to 145 mmHg). Ten patients had mild and 13 patients had moderate‐to‐severe aortic insufficiency (AI) preoperatively. Nine patients had bicuspid aortic valve. Forty patients (45.4%) had associated cardiac lesions. Isolated membranectomy was performed in six patients. Membranectomy associated with septal myectomy was done in 52 patients. Fifteen patients of them associated hypoplasia of the aortic orifice necessitated aortic valve replacement (AVR) using the Konno‐Rastan procedure. Fifteen patients with tunnel SAS and normal aortic valves underwent a combined approach for valve sparing, a modified Konno procedure with patch septoplasty. Also eight patients required AVR because of the severity of AI and five patients aortic reconstruction procedures. Aortic commissurotomy was performed to relief of stenosis in four patients. There were three early deaths (3.4%) and one late death (1.1%) all after the Konno‐Rastan procedure. Eight patients (9.1%) had permanent conduction abnormalities. Postoperative left ventricle‐aorta gradient was significantly decreased at early postoperative period (p < 0.001) and ranged from 10 to 25 mmHg (mean 14.1 ± 4.3). Fourteen patients (16.5%) were reoperated for recurrent obstruction or progression of AI. The mean reoperation interval was 4.4 ± 1.7 years (range 2 to 8 years). Five‐year reoperation‐free survival was 88.0 ± 3.6% and 12.5‐year reoperation‐free survival was 75.5 ± 7.0%. Our results of aggressive surgical approach of subvalvular aortic stenosis produces relief of obstruction and frees the valve leaflets, significantly reducing associated AI with long‐term survival and long‐term adequate relief of left ventricular outflow tract obstruction.


The Annals of Thoracic Surgery | 2002

Five-year experience in aortic root replacement with the flanged composite graft

Kaan Kirali; Denyan Mansuroglu; Suat Nail Omeroglu; Vedat Erentug; Ilker Mataraci; Gökhan İpek; Esat Alcıncı; Omer Isik; Cevat Yakut

BACKGROUND Replacement of the aortic root with a composite graft containing a prosthetic mechanic valve is the preferred surgical procedure for tailoring the aortic root. The aim of this study is to determine the 5-year experience with the composite root replacement using our new modification of the Bentall technique. METHODS Between January 1996 and June 2001, 96 patients underwent aortic root replacement using a flanged composite graft. Eighty patients (83.3%) were male, and 16 patients (16.7%) were female with a mean age of 48.7 +/- 14.4 years. Indications for operation were a true or false aneurysm (65.6%), severe calcified aortic valve stenosis (4.2%) or severe aortic insufficiency (2.1%) with dilated ascending aorta, acute dissection (2.1%), or combination of indications (26%). Thirty-one patients (32.3%) received a concomitant cardiac procedure. Mean aortic cross-clamp time was 89.5 +/- 28.6 minutes, and mean cardiopulmonary bypass time was 146.2 +/- 45.6 minutes. Total follow-up was 253.9 patient-years. RESULTS Operative mortality was 8.3% (8 patients). The causes of hospital mortality were severe bleeding (3 patients), low cardiac output syndrome (2), acute respiratory distress syndrome (2) and cerebrovascular event (1). No patient died of flange-related complications. Univariate predictors of early mortality were low cardiac output syndrome (p < 0.001), neurologic complication (p = 0.03), and renal complication (p = 0.03). Multivariate analysis demonstrated only low cardiac output syndrome to be significant (p = 0.001) predictor for early mortality. There were five (5.7%) late deaths. Actuarial survival was 82.65% +/- 4.8% at 5 years (1.95% patient-year). Cox proportional hazards regression analysis demonstrated only low cardiac output syndrome to be significant (p = 0.032) predictor for late mortality. Actuarial freedom from prosthetic- and technique-related mortality was 100% at 5 years. CONCLUSIONS The flanged composite graft offers excellent long-term results, with very low prevalence of prosthetic-related complications. The new created sinuses and the flange are especially helpful to continue physiologic function of the aortic root.


The Annals of Thoracic Surgery | 1997

Coronary bypass grafting via minithoracotomy on the beating heart

Omer Isik; Bahadır Dağlar; Kaan Kirali; Mehmet Balkanay; Harun Arbatli; Cevat Yakut

BACKGROUND Recently the availability and the superiority of less invasive coronary artery bypass grafting on some selected groups of patients in the meaning of patient comfort and short hospital stay has been shown by some authors. We present here the clinical results of 40 patients operated on by minithoracotomy incision on the beating heart without using cardiopulmonary bypass mostly harvesting the left internal thoracic artery by videothoracoscopic assistance. METHODS Between March 1996 and September 1996, 40 patients were operated on by harvesting the left internal thoracic artery mostly by video-assisted thoracoscopy and performing bypass through a minitoracotomy incision. Two patients in whom the procedure was switched to conventional technique were not included in this series. Nine of the patients were female and the rest were male. The mean age was 43.2 +/- 7. RESULTS Left internal thoracic arteries were harvested by video-assisted thoracoscopy completely in 11 patients, incompletely in 24 patients (the harvesting was completed by direct vision afterwards), and under direct vision in 5 through a mini-anterior thoracotomy incision. Thirty-six patients received a bypass graft to left anterior descending coronary artery only, whereas 4 received a diagonal branch graft also. Left internal thoracic arteries were used to bypass the left anterior descending coronary artery directly in 38 patients. The left internal thoracic artery was injured in the middle portion during harvesting in 1 of the remaining 2 patients. The length was not enough in the other. A short saphenous vein graft was interposed between the left internal thoracic artery and the left anterior descending coronary artery in these 2 patients. There was no mortality. One patient had perioperative myocardial infarction. We did not see serious morbidity except one lung injury due to the trochar. CONCLUSIONS The results obtained from our experience suggest that coronary artery bypass grafting by minithoracotomy could be applied effectively and safely without overwhelming additional risk to the patient. Furthermore, it has some advantages in reducing operative trauma and cost and also improving patient comfort.


The Annals of Thoracic Surgery | 2009

Long-Term Results of Aortic Root Replacement: 15 Years' Experience

Ilker Mataraci; Adil Polat; Burak Kıran; Ahmet C̨alışkan; Altug Tuncer; Vedat Erentug; Kaan Kirali; Omer Isik; Cevat Yakut

BACKGROUND Long-term results of aortic root replacements and the factors affecting long-term mortality were analyzed. METHODS We operated on 254 patients from June 1993 to November 2008 for aortic root replacement with Bentall de Bono procedure. Two hundred five patients were male (80.7%) and 49 patients (19.3%) were female. The mean age was 48.3 +/- 14.7 years (range, 14 to 78 years). We performed 72 concomitant procedures in 69 patients, and the most commonly performed procedure was coronary artery bypass grafting in 37 patients (14.6%). The most common indication for aortic root replacement was aneurysm in 235 patients (92.5%). Thirty-four patients (13.4%) had Marfan syndrome. Hypothermic circulatory arrest was used in 52 patients (20.5%). After removing the clamp, we had to reclamp the aorta in 26 patients (10.2%) undergoing operation. RESULTS Postoperatively 30 patients (11.8%) had in-hospital mortality. The late mortality was 2.8% (7 patients). The most common reason for hospital mortality was low cardiac output (18 in 30 patients; 51.4%). Neurologic complications were seen in 16 patients (6.3%). The mean duration of hospital stay was 16.6 +/- 11.3 days (range, 5 to 77 days). Postoperative follow-up was 6.3 +/- 4.5 years (range, 0 to 15.5 years) on average. Late mortality was significantly affected by Marfan syndrome (p = 0.025) and reclamping the aorta (p = 0.036). Actuarial survival for the overall 254 patients is 88.4% +/- 2.1%, 87.4% +/- 2.2%, and 84.5% +/- 2.56% at 1, 3, and 10 years, respectively. CONCLUSIONS The late-term results of aortic root replacement with the modified Bentall de Bono procedure are satisfactory. Survival is decreased in patients with Marfan syndrome and in the patients who had reclamping intraoperatively.


The Annals of Thoracic Surgery | 2001

Fifteen-year clinical experience with the Biocor porcine bioprostheses in the mitral position

Kaan Kirali; Mustafa O. Guler; Altug Tuncer; Bahadır Dağlar; Gökhan İpek; Omer Isik; Cevat Yakut

BACKGROUND Bioprosthetic valve use represents a crucial improvement in surgical treatment of mitral valve disease. The aim of this study is to determine the long-term durability of the Biocor porcine bioprosthetic mitral valve. METHODS Between 1985 and 1989, a total of 158 Biocor porcine bioprosthetic valves were placed in the mitral position, and long-term results of these patients were investigated retrospectively in 1999. RESULTS Thirty-day mortality was 4.4% (7 patients). Total follow-up was 1,499 patient-years. Actuarial survival was 83.66% +/- 3% at 5 years, 77.78% +/- 3.36% at 13 years (1.8% patient-year). Multivariate analysis demonstrated younger age, duration of implantation, congestive heart failure, and functional class to be significant predictors of late mortality. Actuarial freedom from valve-related mortality was 98.58% +/- 1% at 15 years (0.13% patient-year). Actuarial freedom from structural valve deterioration was 95.49% +/- 1.8% at 5 years, 70.2% +/- 4.12% at 10 years, and 64.82% +/- 5.34% at 13 years (2.6% patient-year). Actuarial freedom from structural valve deterioration-related reoperation was 98.43% +/- 1.1% at 5 years, 89.15% +/- 2.85% at 10 years, and 76.82% +/- 7.91% at 14 years. Multivariate analysis showed younger age and duration of implantation to be significant predictors of structural valve deterioration and its related reoperation. CONCLUSIONS By studying a 15-year time period, it is seen that this new generation porcine bioprosthetic valve should be considered an alternative for mechanical valves in selected patients.


Vascular and Endovascular Surgery | 2012

Comparison Between Local and General Anesthesia for Carotid Endarterectomy: Early and Late Results

Onur Gürer; Fikri Yapici; Nihan Yapici; Azmi Ozler; Omer Isik

Background: The aim of this retrospective study was to compare the results between general and local anesthesia (LA) for carotid endarterectomy (CEA). Methods: Three hundred and twenty-nine patients in whom 365 CEA procedures were performed between January 1990 and September 2001, were included in this study. Results: Operation time, shunt usage rates, hospitalization time (P < .0001), and permanent stroke rates (P < .05) were significantly lower in group with LA. For long-term period (121.3 ± 37.45 vs 98.6 ± 28.98 months), no significant difference was observed in these 2 group with respect to restenosis rates, neurological events, and deaths. Conclusions: Despite the lack of significant difference between LA and general anesthesia in terms of restenosis, neurological events, and death in the long-term period; LA is more preferable due its associated advantages including availability of testing the consciousness of the patients by direct contact, reduced use of shunts, shorter hospitalization periods, and less prevalence of permanent stroke in the short-term period.


Cardiology Journal | 2012

Comparison of inhaled nitric oxide and aerosolized iloprost in pulmonary hypertension in children with congenital heart surgery

Ahmet Kırbaş; Yalim Yalcin; Nursen Tanrıkulu; Onur Gurer; Omer Isik

BACKGROUND Pulmonary arterial hypertension is of importance in congenital cardiac surgery as being a significant cause of morbidity and mortality. Although therapy options are limited, inhaled nitric oxide (NO) is used as a standard therapy. The present study aimed to compare inhaled NO and aerosolized iloprost in children with secondary pulmonary hypertension who underwent congenital cardiac surgery. METHODS Sixteen children included in the study were randomized into either inhaled NO or aerosolized iloprost group. For both groups, the observation period terminated at 72 h after cardiopulmonary bypass. RESULTS There was no significant difference between the groups in terms of mean age, weight, cross clamp time, pump time, and extubation time. No significant change was observed in the arterial tension and central venous pressure of both groups before the operation, 30 min after the pump, 45 min after the pump, and after extubation, whereas an increase was observed in the heart rate and cardiac output, and a decrease was observed in the pulmonary artery pressure. The mean values at the above-mentioned time points showed no difference between the groups. No serious adverse event and mortality was detected. CONCLUSIONS Both inhaled NO and aerosolized iloprost were found to be effective and comparable in the management of pulmonary hypertension.


Cardiovascular Surgery | 2002

Long-term comparison of aortic arch replacement with or without elephant trunk procedure via retrograde cerebral perfusion for aortic arch dissection.

Kaan Kirali; Suat Nail Omeroglu; Hasan Ardal; Mehmet Erdem Toker; Hasan Basri Erdogan; Bahadır Dağlar; Mehmet Balkanay; Gökhan İpek; Omer Isik; Cevat Yakut

OBJECTIVE The aim of this study is to investigate the effects of the duration of retrograde cerebral perfusion (RCP) in patients with aortic arch dissection. METHODS Between 1993 and December 2000, 56 patients were operated on for aortic arch dissection. Elephant trunk procedure was performed in 28 patients (Group A) and semiarcus replacement in 28 patients (Group B). Type I dissection (P=0.003), chronic ethiology (P=0.006), medial degeneration (P<0.001), and preoperative hemodynamic instability (P=0.004) were observed significantly more in Group A. In both groups RCP was used for cerebral protection. RESULTS Hospital mortality was higher in Group A than Group B (32.1% versus 7.1%; P=0.015). Late mortality was observed only in Group A (10.5%; P=0.049). Actuarial survival was 55.1+/-11.55% in Group A and 91.67+/-5.64% in Group B at 5 yr (P=0.0113), while cumulative survival for all patients was 78.38+/-5.77% at 5 yr. RCP time was longer in Group A (62.7+/-16.8 versus 34.2+/-19.5 min; P<0.001). Forward stepwise logistic regression analysis showed that chronic obstructive pulmonary disease (P=0.014) and renal insufficiency (P=0.004) were significantly predictors for hospital mortality, whereas elephant trunk (P=0.052) and RCP (>60 min) (P=0.175) did not increase early mortality. Only hemodynamic instability was significantly (P=0.006) predictors for late mortality. CONCLUSIONS Preoperative severity of dissection, hemodynamic instability or organ dysfunctions impair early or late outcome. Elephant trunk technique with increased RCP time do not increase early or late mortality. To shorten RCP time (<60-65 min) can improve surgical results.


Asian Cardiovascular and Thoracic Annals | 2004

Partial cardiac autotransplantation for reduction of the left atrium.

Hasan Basri Erdogan; Kaan Kirali; Suat Nail Omeroglu; Deniz Göksedef; Omer Isik; Cevat Yakut

Various surgical procedures have been employed to treat a greatly enlarged left atrium. We review the use of partial cardiac autotransplantation to reduce left atrial volume in 7 patients with rheumatic mitral valve disease and left atrial and ventricular volume in 2 patients with idiopathic dilated cardiomyopathy. There were 5 males and 4 females aged 25 to 62 years. The patients with rheumatic etiology had atrial fibrillation, while those with dilated cardiomyopathy had sinus rhythm. The mitral valve was replaced in 6 patients and reconstructed in 3. Mean aortic cross clamp time in the operations involving isolated left atrial resection was 119 ± 44 min. Mean left atrial volume fell from 331 mL to 92 mL, while mean left atrial diameter decreased from 8.6 cm to 4.7 cm. Sinus rhythm was restored in 5 of the 7 patients who had preoperative atrial fibrillation. There was no operative mortality. The patients with dilated cardiomyopathy died in the postoperative period, one on the 14th day from low cardiac output and the other on the 113th day from multiorgan failure. Partial cardiac autotransplantation can be effective in reducing heart chamber size in selected patients, especially those with giant left atrium.

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Cevat Yakut

Yüzüncü Yıl University

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