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Dive into the research topics where Ali Ümit Yener is active.

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Featured researches published by Ali Ümit Yener.


Heart Lung and Circulation | 2014

Use of Extracorporeal Membrane Oxygenation in Adults

Gokhan Lafci; Ali Baran Budak; Ali Ümit Yener; Ömer Faruk Çiçek

Since the first successful application of the heart-lung machine in 1953 by John Gibbon [1], great efforts have been made to modify the bypass techniques and devices in order to allow prolonged extracorporeal circulation in the intensive care unit (ICU), commonly referred to as extracorporeal membrane oxygenation (ECMO). ECMO uses classic cardiopulmonary bypass technology to support circulation. It provides continuous, non-pulsatile cardiac output and extracorporeal oxygenation [2]. Veno-venous ECMO (VV ECMO) provides respiratory support, while veno-arterial ECMO (VA ECMO) provides cardio-respiratory support to patients with severe but potentially reversible cardiac or respiratory deterioration refractory to standard therapeutic modalities. ECMO is a temporary form of life support providing a prolonged biventricular circulatory and pulmonary support for patients experiencing both pulmonary and cardiac failure unresponsive to conventional therapy. Despite the advent of newer ventricular assist devices that are more suitable for long term support, ECMO is simple to establish, cost-effective to operate.


Cardiovascular Journal of Africa | 2013

Comparison of one- and two-stage basilic vein transposition for arterio-venous fistula formation in haemodialysis patients: preliminary results.

Sedat Özcan; Ali Ümit Yener; Ali Kemal Gür; Dolunay Odabasi

Summary Objective This study aimed to compare the results of one-and two-stage basilic vein transposition (BVT) in haemodialysis patients. Methods This was a non-randomised, retrospective study between January 2007 and January 2012 on 96 patients who were diagnosed with end-stage renal failure (ESRF) (54 males, 42 females; mean age 43.6 ± 14 years) and underwent one- or two-stage BVT in our clinic. All patients who were not eligible for a native radio-cephalic or brachio-cephalic arterio-venous fistula (AVF) were scheduled for one- or two-stage BVT after arterial (brachial, radial and ulnar) and venous (basilic and cephalic) Doppler ultrasonography. Patients were retrospectively divided into two groups: group 1, basilic vein diameter > 3 mm and patients who underwent one-stage BVT; and group 2, basilic vein diameter < 3 mm and patients who underwent two-stage BVT. In group 1, the basilic vein with a single incision was anastomosed to the brachial artery, followed by superficialisation. In group 2, the basilic vein was anastomosed to the brachial artery and they underwent the superficialisation procedure one month postoperatively. Fistula maturation and postoperative complications were assessed. Results The mean diameter of the basilic vein was statistically significantly higher in group 1 (3.46 ± 0.2 mm) than in group 2 (2.79 ± 0.1 mm) (p < 0.05). In terms of postoperative complications, thrombosis, haemorrhage and haematoma were significantly higher in group 1 (34, 36 and 17%, respectively) than in group 2 (23, 14 and 6%, respectively) (p < 0.05). The rate of fistula maturation was significantly lower in group 1 (66%), compared to group 2 (77%) (p < 0.05). Time to fistula maturation was significantly shorter in group 1 (mean 41 ± 14 days), compared to group 2 (mean 64 ± 28 days) (p < 0.05). Conclusion Two-stage BVT was superior to one-stage BVT due to its lower rate of postoperative complications and higher fistula maturation, despite its disadvantage of late fistula use. Although the diameter of the basilic vein was larger in patients who underwent one-stage BVT, we observed that one-stage BVT was disadvantageous in terms of postoperative complications and fistula maturation.


Angiology | 2015

Increased Platelet Distribution Width Is Associated With Severity of Coronary Artery Disease in Patients With Acute Coronary Syndrome

Adem Bekler; Muhammed Turgut Alper Özkan; Erhan Tenekecioglu; Emine Gazi; Ali Ümit Yener; Ahmet Temiz; Burak Altun; Ahmet Barutcu; Gökhan Erbağ; Emine Binnetoglu

Platelet activation plays a pivotal role in acute coronary syndrome (ACS). We investigated the relationship between platelet distribution width (PDW) and severity of coronary artery disease (CAD) in patients with ACS. A total of 502 patients with ACS were enrolled. High (n = 151) and low PDW (n = 351) groups were defined as patients having values in the third tertile (>17%) and lower 2 tertiles (≤17%). There were significantly higher Gensini score (44 [10-168] vs 36 [2-132], P < .001), and neutrophil–lymphocyte ratio (3.1 [0.8-12.4] vs 2.5 [0.3-13], P = .012) and baseline platelet counts were significantly lower (220 [61-623] vs 233 [79-644] 103/mm3, P = .022) in the high PDW group. The variables PDW >17%, diabetes mellitus, and myocardial infarction were found to be associated with high Gensini score (odds ratio [OR]: 1.91, 95% confidence interval [CI]: 1.27-2.88, P = .002; OR: 2.85, 95%CI: 1.91-4.25, P < .001; OR: 2.67, 95% CI:1.74-4.1, P < .001, respectively). An increased PDW (>17%) is associated with severity of CAD in patients with ACS.


Canadian Association of Radiologists Journal-journal De L Association Canadienne Des Radiologistes | 2015

The normal anatomy and variations of the bronchial arteries: evaluation with multidetector computed tomography.

Özlem Yener; Aysel Türkvatan; Gökhan Yüce; Ali Ümit Yener

Introduction In this study, we aimed to reveal the normal anatomy and variations of the bronchial arterial system and to determine the sex distribution of these variations by retrospectively reviewing the images of patients who underwent thoracal multidetector computed tomographic angiography for various reasons. Materials and Methods Multidetector computed tomographic images of a total of 208 patients (151 men; mean age, 59 years) were retrospectively reviewed to assess the normal anatomy and variations of the bronchial arterial system. Results A total of 531 bronchial arteries (median, 3; minimum, 1; maximum, 5; mean, 2.5) were detected. The number (mean diameter) of the right bronchial arteries were higher than the left bronchial arteries (290 [1.43 mm] and 241 [1.26 mm], respectively; P < .05 for both number and diameter). The mean number (diameter) of the bronchial arteries were higher with men than with women (2.58 [1.45 mm] and 2.47 [1.32 mm], respectively; P < .05 for both number and diameter). The most common (24%) branching pattern was the combination of 1 right intercostal-bronchial trunk and 1 left bronchial artery, and, secondarily (13.46%), the combination of 2 right (1 intercostal-bronchial trunk and 1 bronchial artery) and 1 left bronchial arteries. Seventy-eight ectopic bronchial arteries were detected in 59 cases (28.3%). They most commonly originated from the aortic arch (37.2%), the descending aorta below the level of T6 (35.9%), or the aortic branches (16.7%). The number of right ectopic bronchial arteries was significantly higher than the left ectopic bronchial arteries (50 [64%] vs 28 [36%]; P < .01). The incidence of ectopic bronchial arteries was statistically higher with men versus women (45 [29.8%] vs 14 [24.6%]; P < .05). Conclusion The origins, numbers, diameters, and courses of the bronchial arteries can vary substantially among individuals. Multidetector computed tomographic angiography enables a detailed road map of the bronchial arterial system to interventional radiologists and thoracic surgeons.


Kardiologia Polska | 2015

The relationship between fragmented QRS complexes and SYNTAX and Gensini scores in patients with acute coronary syndrome

Adem Bekler; Ahmet Barutcu; Erhan Tenekecioglu; Burak Altun; Emine Gazi; Ahmet Temiz; Bahadir Kirilmaz; Muhammed Turgut Alper Özkan; Ali Ümit Yener

BACKGROUND Fragmented QRS (fQRS) complexes on 12-lead electrocardiography (ECG) have been reported to be predictors of cardiac events and all-cause mortality in coronary artery disease (CAD). AIM To investigate the relationship between fQRS complexes and SYNTAX and Gensini scores in patients with acute coronary syndrome (ACS). METHODS A total of 302 patients (223 men and 79 women) with ACS (133 ST elevated myocardial infarction [STEMI], 107 non-STEMI [NSTEMI], and 62 unstable angina pectoris [USAP]) were evaluated retrospectively in this study. An fQRS pattern was found in 70 patients (fQRS group) but was not found in 232 patients (non-fQRS group). SYNTAX score > 22 and Gensini score > 20 were defined as high SYNTAX and Gensini scores. The relationship between the presence of fQRS on 12-lead ECG and SYNTAX and Gensini scores was assessed. RESULTS SYNTAX score (p < 0.001), Gensini score (p < 0.001), NYHA class (p < 0.001), QRS duration (p < 0.001), number of disease vessels (p = 0.003), and high sensitive troponin T levels (p = 0.026) were significantly higher in the fQRS group. The number of fQRS leads (HR 5.79, 95% CI 2.78-12.06, p < 0.001, HR 3.41, 95% CI 1.32-8.78, p = 0.016, respectively) was found to be an independent predictor of high SYNTAX score and high Gensini score in multivariate analysis. CONCLUSIONS The number of fQRS leads on 12-lead ECG on admission is associated with the severity and complexity of CAD in patients with ACS.


Journal of Korean Neurosurgical Society | 2015

The Neuroprotective Effect of Kefir on Spinal Cord Ischemia/Reperfusion Injury in Rats

Mustafa Guven; Tarık Akman; Ali Ümit Yener; Muserref Hilal Sehitoglu; Yasemin Yuksel; Murat Cosar

Objective The main causes of spinal cord ischemia are a variety of vascular pathologies causing acute arterial occlusions. We investigated neuroprotective effects of kefir on spinal cord ischemia injury in rats. Methods Rats were divided into three groups : 1) sham operated control rats; 2) spinal cord ischemia group fed on a standard diet without kefir pretreatment; and 3) spinal cord ischemia group fed on a standard diet plus kefir. Spinal cord ischemia was performed by the infrarenal aorta cross-clamping model. The spinal cord was removed after the procedure. The biochemical and histopathological changes were observed within the samples. Functional assessment was performed for neurological deficit scores. Results The kefir group was compared with the ischemia group, a significant decrease in malondialdehyde levels was observed (p<0.05). Catalase and superoxide dismutase levels of the kefir group were significantly higher than ischemia group (p<0.05). In histopathological samples, the kefir group is compared with ischemia group, there was a significant decrease in numbers of dead and degenerated neurons (p<0.05). In immunohistochemical staining, hipoxia-inducible factor-1α and caspase 3 immunopositive neurons were significantly decreased in kefir group compared with ischemia group (p<0.05). The neurological deficit scores of kefir group were significantly higher than ischemia group at 24 h (p<0.05). Conclusion Our study revealed that kefir pretreatment in spinal cord ischemia/reperfusion reduced oxidative stress and neuronal degeneration as a neuroprotective agent. Ultrastructural studies are required in order for kefir to be developed as a promising therapeutic agent to be utilized for human spinal cord ischemia in the future.


Anatolian Journal of Cardiology | 2014

Fragmented QRS is associated with frequency of premature ventricular contractions in patients without overt cardiac disease.

Ahmet Temiz; Emine Gazi; Burak Altun; Ömer Güngör; Ahmet Barutçu; Adem Bekler; Yusuf Ziya Tan; Ali Ümit Yener; Mustafa Saçar; Yucel Colkesen

Objective: In this study, we aimed to demonstrate whether the presence of fragmented QRS (fQRS) is associated with the frequency of premature ventricular contractions (PVCs). Methods: We retrospectively analyzed 282 cases by 24-hour Holter monitorings (HMs) between August 2012 and February 2013. Firstly, the patients were divided into 2 groups with respect to presence of fQRS and then divided into 3 groups with respect to frequency of PVCs as Group 1: seldom PVC (<120 PVCs/day), Group 2: moderate-frequency PVC (120-720 PVCs/day), and Group 3: frequent PVC (>720 PVCs/day). We investigated the predictors of frequent PVCs by using multinomial logistic regression analysis. Results: Ninety-eight patients had fQRS. There was no difference between the 2 groups with respect to body mass index, gender, hypertension, and diabetes mellitus. Patients with fQRS were older (54.9±15.6 vs. 47.0±16.3, p<0.001) and had more family history of coronary artery disease (25% vs. 13%, p=0.012). Patients with fQRS was more likely to be on aspirin therapy (28.6% vs. 10.4%, p<0.001) and have a larger left atrium diameter (33.5±5.7 vs. 30.4±5.8, p=0.001). Presence of fQRS was significantly associated with the frequency of PVCs (for frequent PVC 27.7% vs. 7.6%, p<0.001; for moderate-frequency PVC 18.4% vs. 11.4%, p=0.012); 26.2% of Group 1 (n=202) had fQRS, 46.2% of Group 2 (n=39) had fQRS, and 65.9% of Group 3 (n=41) had fQRS. In the multinomial regression analysis, only age (odds ratio: 4.24, 95% confidence interval 2.08-8.64, p=0.001) and fQRS (odds ratio: 2.11, 95% confidence interval 1.00-4.45, p=0.05) were predictors of frequent PVCs. Conclusion: This study demonstrated that the presence of fQRS is associated with frequent PVCs in patients without overt structural heart disease.


Cardiovascular Journal of Africa | 2013

tumescentless endovenous radiofrequency ablation with local hypothermia and compression technique

Kemal Korkmaz; Ali Ümit Yener; Hikmet Selçuk Gedik; Ali Baran Budak; Ozlem Yener; Serhat Bahadir Genc; Ayse Lafci

Introduction Modern surgical management of chronic venous insufficiency is possible since the development of catheter-based minimally invasive techniques, including radiofrequency ablation (RFA) and the application of colour Doppler sonography. RFA technology requires the use of tumescent anaesthesia, which prolongs the operating time. Instilling tumescent anaesthesia percutaneously below the saphenous fascia is the steepest part of the learning curve. In our study, we compared operative and postoperative results of tumescentless RFA and RFA with tumescent anaesthesia, to investigate the necessity of tumescent anaesthesia. Methods A total of 344 patients with Doppler-confirmed great saphenous vein insufficiency underwent RFA between January and December 2012. Patients were divided into two groups according to anaesthetic management. Group 1 consisted of 172 patients: tumescent anaesthesia was given before the ablation procedure, and group 2 contained 172 patients: a local hypothermia and compression technique was used; no tumescent anaesthesia was administered. The visual analogue scale (VAS) was used and ecchymosis scores of the patients were recorded. Clinical examinations were performed at each visit and Doppler ultrasonography was performed in the first and sixth month. Results Mean ablation time was significantly lower in group 2 compared to group 1 (7.2 vs 18.9 min; p < 0.05). Skin burn and paresthesia did not occur. The immediate occlusion rate was 100% for both groups. No significant difference was found between the groups in terms of VAS and ecchymosis scores. All patients returned to normal activity within two days. The primary closure rate of group 1 was 98.2% and group 2 was 98.8% at six months, and there was no significant difference between the groups (p > 0.05). Conclusion Eliminating tumescent infusion is a desirable goal. Tumescentless endovenous RFA with local hypothermia and compression technique appears to be safe and efficacious. Our technique shortens the operation time and prevents patient procedural discomfort.


Journal of Surgical Research | 2016

Is hyperbaric oxygen or ozone effective in experimental endocarditis

Muhammed Turgut Alper Özkan; Ahmet Vural; Ömer Faruk Çiçek; Ali Ümit Yener; Sedat Özcan; Hüseyin Toman; Ahmet Ünver; Mustafa Saçar

BACKGROUND Infective endocarditis, a disease with high mortality and morbidity, is most commonly caused by Staphylococcus aureus; mortality and morbidity further increase in the presence of methicillin-resistant strains of S. aureus. Linezolid is the first of the oxazolidinones, a new antibiotic group that has been approved for the treatment of infections caused by gram-positive cocci. Linezolid reduces the quantity of microorganisms in vegetation to some extent; in addition, the use of hyperbaric oxygen (HBO) and ozone (O3) therapies is likely to improve targeted antibacterial effect. MATERIALS AND METHODS Fifty-six adult male Wistar rats weighing 300-350 g were used. The subjects were divided into groups as follows: Group 1 (n = 8): control group that was not inoculated with microorganisms and was untreated; Group 2 (n = 8): control group that was inoculated with microorganisms but was untreated; Group 3 (n = 8): linezolid treatment group; Group 4 (n = 8): O3 therapy group; Group 5 (n = 8): HBO therapy group; Group 6 (n = 8): linezolid + O3 therapy group; Group 7 (n = 8): linezolid + HBO therapy group. RESULTS In terms of reducing the number of colonies in the aortic valve, linezolid + HBO therapy was found to be the most effective treatment. Then, respectively linezolid + O3, linezolid, HBO, and O3 were found to be effective. CONCLUSIONS We found that linezolid significantly reduced the number of bacteria in the vegetation in the experimental endocarditis model, and HBO therapy increases the effectiveness of linezolid and makes this better than O3.


Brazilian Journal of Cardiovascular Surgery | 2015

Adjunctive Hyperbaric Oxygen Therapy or Alone Antibiotherapy? Methicillin Resistant Staphylococcus aureus Mediastinitis in a Rat Model

Tolga Kurt; Ahmet Vural; Ahmet Temiz; Ersan Ozbudak; Ali Ümit Yener; Suzan Sacar; Mustafa Saçar

OBJECTIVE In the post-sternotomy mediastinitis patients, Staphylococcus aureus is the pathogenic microorganism encountered most often. In our study, we aimed to determine the efficacy of antibiotic treatment with vancomycin and tigecycline, alone or in combination with hyperbaric oxygen treatment, on bacterial elimination in experimental S. aureus mediastinitis. METHODS Forty-nine adult female Wistar rats were used. They were randomly divided into seven groups, as follows: non-contaminated, contaminated control, vancomycin, tigecycline, hyperbaric oxygen, hyperbaric oxygen + vancomycin and hyperbaric oxygen + tigecycline. The vancomycin rat group received 10 mg/kg/day of vancomycin twice a day through intramuscular injection. The tigecycline group rats received 7 mg/kg/day of tigecycline twice a day through intraperitoneal injection. The hyperbaric oxygen group underwent 90 min sessions of 100% oxygen at 2.5 atm pressure. Treatment continued for 7 days. Twelve hours after the end of treatment, tissue samples were obtained from the upper part of the sternum for bacterial count assessment. RESULTS When the quantitative bacterial counts of the untreated contaminated group were compared with those of the treated groups, a significant decrease was observed. However, comparing the antibiotic groups with the same antibiotic combined with hyperbaric oxygen, there was a significant reduction in microorganisms identified (P<0.05). Comparing hyperbaric oxygen used alone with the vancomycin and tigecycline groups, it was seen that the effect was not significant (P<0.05). CONCLUSION We believe that the combination of hyperbaric oxygen with antibiotics had a significant effect on mediastinitis resulting from methicillin-resistant Staphylococcus aureus. Methicillin-resistant Staphylococcus aureus mediastinitis can be treated without requiring a multidrug combination, thereby reducing the medication dose and concomitantly decreasing the side effects.

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Dive into the Ali Ümit Yener's collaboration.

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Sedat Özcan

Çanakkale Onsekiz Mart University

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Kemal Korkmaz

Çanakkale Onsekiz Mart University

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Adem Bekler

Çanakkale Onsekiz Mart University

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Tolga Kurt

Çanakkale Onsekiz Mart University

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Emine Gazi

Çanakkale Onsekiz Mart University

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Ahmet Temiz

Çanakkale Onsekiz Mart University

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Hüseyin Toman

Çanakkale Onsekiz Mart University

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Turgut Özkan

Çanakkale Onsekiz Mart University

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Burak Altun

Kahramanmaraş Sütçü İmam University

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