Browsing by Author "Ozulku, Mehmet"

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Effect of L-arginine on Hemodynamic, Biochemical, and Histopathological Outcomes in a New Zealand Rabbit Model of Renal Ischemia-Reperfusion Injury
(2016) Ozulku, Mehmet; Aygun, Fatih
Objective: In this study, we investigated the effect of L-arginine on hemodynamic, biochemical, and histopathological changes in a rabbit model with renal ischemia. Methods: Forty white New Zealand rabbits were used. The rabbits were divided into two groups as the control group (n=20) and L-arginine group (n=20). They were monitored by cannulating the auricular and femoral arteries. An aortic occlusion catheter was inserted through the contralateral femoral artery and was extended to the distal aspect of the left subclavian artery; it was then inflated, and occlusion was performed for 30 min. All rabbits received 4 mL/kg/h of NaCl infusion during the course of occlusion and within the first 60 min of reperfusion. In the L-arginine group, L-arginine was infused at a dosage of 3 mg/kg/h through the auricular vein during the first 60 min of occlusion and perfusion. Blood samples for biochemical parameters [glucose, lactate, hematocrit, blood urea nitrogen (BUN), and serum creatinine] were obtained in the peri-ischemic period, in the 20th minute of reperfusion, and just before sacrificing (48th hour). A histopathological examination was performed in both renal tissues. Histopathological scoring was performed by taking tubular epithelial cell flattening, brush border loss, cytoplasmic vacuolization, cell necrosis, and tubular lumen obstruction into consideration. All animals were sacrificed 48 h after the procedure. Results: A significant difference was found between the L-arginine and control groups in terms of the hemodynamic outcomes and 48th hour BUN and serum creatinine levels (p<0.05). The histopathological examination revealed a mean score of 3.2 +/- 0.89 in the control group and 2.60 +/- 0.68 in the L-arginine group (p<0.05) (p=0.022). Conclusion: It can be suggested that L-arginine reduces renal ischemia-reperfusion injury and in particular, the histopathological effects.
Effect of LIMA Harvesting Technique on Postoperative Drainage in Off-Pump CABG
(2016) Ozulku, Mehmet; Aygun, Fatih; 27556310
Objective: We investigated the effects of pedicled and semiskeletonized left internal mammary artery (LIMA) harvesting techniques on postoperative drainage in patients subjected to off-pump CABG, ignoring other advantages or disadvantages of those techniques. Methods: The present study comprises a total of 160 subjects that underwent coronary artery bypass surgery in our clinic. Data were collected consecutively and retrospectively. An attempt was made to have similar groups in terms of demographic characteristics. Patients that underwent off-pump coronary artery bypass surgery by two surgical teams which differed only in LIMA harvesting technique were dichotomized and compared according to these techniques. The first group (Group 1) consisted of patients in whom LIMA was harvested with surrounding tissues using the pedicled technique. The second group (Group 2) consisted of patients in whom LIMA was harvested using the semiskeletonized technique, with the veins separated from surrounding connective tissues. Results: The mean amount of drainage in the first 24 hours was 706.1 +/- 234.2 ml vs. 591 +/- 258.8 ml (Group 1 vs. Group 2; P=0.005), the mean amount of drainage in the second 24 hours was 270 +/- 133.6 ml vs. 189.4 +/- 140.4 ml (Group 1 vs. Group 2; P < 0.001), and the mean amount of total drainage was determined to be 976.1 +/- 306.9 ml vs. 781.2 +/- 335.5 ml (Group 1 vs. Group 2; P < 0.001). Conclusion: It was observed that semiskeletonized LIMA presents reduced amount of postoperative drainage in the first and second 24-hour periods and total amount of drainage than pedicled LIMA, independent of pleural integrity.
Effect of using pump on postoperative pleural effusion in the patients that underwent CABG
(2015) Ozulku, Mehmet; Aygun, Fatih; 27163421
Objective: The present study investigated effect of using pump on postoperative pleural effusion in patients who underwent coronary artery bypass grafting. Methods: A total of 256 patients who underwent isolated coronary artery bypass grafting surgery in the Cardiovascular Surgery clinic were enrolled in the study. Jostra-Cobe (Model 043213 105, VLC 865, Sweden) heart-lung machine was used in on-pump coronary artery bypass grafting. Off-pump coronary artery bypass grafting was performed using Octopus and Starfish. Proximal anastomoses to the aorta in both on-pump and off-pump techniques were performed by side clamps. The patients were discharged from the hospital between postoperative day 6 and day 11. Results: The incidence of postoperative right pleural effusion and bilateral pleural effusion was found to be higher as a count in Group 1 (on-pump) as compared to Group 2 (off-pump). But the difference was not statistically significant [P>0.05 for right pleural effusion (P=0.893), P>0.05 for bilateral pleural effusion (P=0.780)]. Left pleural effusion was encountered to be lower in Group 2 (off-pump). The difference was found to be statistically significant (P<0.05, P=0.006). Conclusion: Under the light of these results, it can be said that left pleural effusion is less prevalent in the patients that underwent off-pump coronary artery bypass grafting when compared to the patients that underwent on-pump coronary artery bypass grafting.
The Influence of On-pump Versus Off-pump Surgery on Short- and Medium-term Postoperative Coronary Flow Reserve After Coronary Artery Bypass Grafting
(2016) Ozulku, Mehmet; Caliskan, Mustafa; Saba, Tonguc; Aksu, Feyza; Ciftci, Ozgur; Gullu, Hakan; Guven, Aytekin; Kostek, Osman; Caklili, Ozge Telci; Aslamaci, Sait; 0000-0001-7566-5427; 0000-0002-9635-6313; 0000-0002-1901-5603; 27269474; AAT-7733-2020; AAG-8233-2020; AAA-3604-2019; AAJ-8546-2021
Background Although several clinical trials have compared surgical outcomes between off-pump and on-pump coronary artery bypass grafting (CABG), whether there is a difference in the early- and medium-term postoperative coronary microvascular functions is not fully understood. We compared short- and medium-term coronary microvascular function after off-pump and on-pump CABG. Methods A prospective study of patients undergoing off-pump and on-pump CABG. Eighty-two patients scheduled for CABG were recruited: 38 underwent off-pump surgery and 44 on-pump surgery. Each participant's coronary flow reserve (CFR) and diastolic function were measured with transthoracic Doppler echocardiography six and 12 months after surgery. Results Baseline and hyperaemic diastolic peak flow velocity in the left anterior descending artery were similar in both groups, as was CFR (2.22 +/- 0.66) in the off-pump group compared with (2.13 +/- 0.61) in the on-pump group, (P = 0.54). Coronary flow reserve was significantly and inversely correlated with high sensitivity C-reactive protein concentration (r = -0.416; P < 0.001) and positively correlated with mitral E/ A-wave velocity ratio (r = 0.247; P = 0.02). Stepwise linear regression analysis revealed that only high sensitivity C-reactive protein concentration was independently correlated with CFR (beta = -0.272, P = 0.02). Conclusions Heart-lung bypass technique had no medium-term influence on the coronary microcirculation, despite a possible initial unfavourable effect. Serum hs-CRP concentration was an independent predictor of medium-term coronary microvascular dysfunction.
Interrelation of RDW and coronary flow reserve in patient with idiopathic dilated cardiomyopathy
(2014) Ozulku, Mehmet; Caliskan, Mustafa; Gullu, Hakan; Erdogan, Dogan; Caliskan, Zuhal; Muderrisoglu, Haldun
Objective: Idiopathic dilated cardiomyopathy (IDC) impairs and reduces coronary flow reserve (CFR). High level of red cell distribution width (RDW) is an independent risk factor for cardiovascular diseases. Therefore, in this observational case-control study we have aimed to determine whether RDW level is associated with CFR impairment in patients with IDC. Methods: We examined 36 patients with IDC and 35 healthy subjects formed as a control group. In addition to this, patients with IDC were divided into two subgroups according to their CFR levels [normal CFR group (CFR value >= 2) and lower CFR group (CFR value<2)]. Control and patients groups were compared using the student t-test for multiple comparisons. The subgroups were compared using the Mann-Whitney U test for continuous variables and chi-square for categorical variables. The Pearson's and Spearman correlation analysis was used to test the possible associations between CFR and the study variables as appropriate. The receiver-operating characteristic (ROC) curve was determined to evaluate the predictive performance of RDW to detect low CFR. Results: There were no significantly differences between the lower and higher CFR groups' clinical data, baseline hemodynamic, medication and biochemical data except RDW and high-sensitivity C-reactive protein (hsCRP) levels. We found that RDW level was a good predictor of low CFR at the receiver-operating characteristic curve. The area under the curve (AUC) was 73% (95% confidence interval between 0.56-0.90 is 95%, p:0.018) After adjusting potential confounders include age, body-mass index, blood pressure, lipid and glucose, RDW independently associated with CFR level (Beta:-0.374; p=0.015) and hsCRP value (Beta:-0.520; p=0.001) were the independent predictors of lower CFR. Conclusion: Results showed that there was an independent correlation between RDW level and CFR level in patients with IDC.
Is Off-Pump Coronary Artery Bypass Surgery Superior to On-Pump Coronary Artery Bypass Surgery on Postoperative Paradoxical Ventricular Septal Motion?
(2014) Gunday, Murat; Alpaslan, Mete; Ciftci, Ozgur; Ozulku, Mehmet; Copur, Gulay; Aslamaci, Sait; https://orcid.org/0000-0003-1481-8228; https://orcid.org/0000-0002-6463-6070; 25179970; A-7318-2017
Background: The aims of this study were to investigate the appearance of paradoxical ventricular septal motion (PSM) after coronary artery bypass graft (CABG) surgery and to identify factors that might be related to this abnormality. Methods: This prospective study included 119 consecutive patients (38 women, 81 men) who underwent CABG. Patients who underwent on-pump surgery (22 women, 45 men) and patients who underwent off-pump surgery (16 women, 36 men) were studied separately. All subjects underwent preoperative angiographic septal perfusion evaluation, pre- and postoperative echocardiography, and standard electrocardiographic and laboratory investigations, including troponin I and CK-MB levels. Multivariate logistic regression analysis was also performed for a variety of related parameters. Results: Significant differences in EuroSCORE, length of intensive care unit stay, length of hospital stay, PSM (assessed using echocardiography), septal perfusion (observed using preoperative angiography), postoperative pleural effusion, and intensive care unit recidivism were observed between the two groups (P < .05). Moreover, postoperative PSM was correlated with septal perfusion (r = -0.687**, P < .001), type of operation (r = -0.194*, P = .035), diabetes mellitus (r = 0.273**, P = .003), carotid stenosis (r = 0.235*, P = .011), the number of distal anastomoses (r = 0.245**, P = .008), pleural effusion (r = 0.193*, P = .037), and intensive care unit recidivism (r = 0.249**, P = .007). However, multivariate analysis demonstrated that only preoperative septal perfusion (odds ratio: 0.037; 95% confidence interval: 0.011-0.128; P < .05) constitutes an independent risk factor for PSM (P < .05). Conclusions: This study demonstrated that preoperative septal perfusion deficiency represents an independent risk factor for postoperative PSM in patients undergoing CABG. Further investigations addressing the timing of the appearance of PSM and the correlation of this finding with perfusion imaging studies may provide new details concerning the mechanisms that underlie this abnormality.
IS THERE A REAL CORRELATION BETWEEN RED CELL DISTRIBUTION WIDTH AND PERIPHERAL ARTERIAL DISEASE?
(2017) Duman, Enes; Kulaksizoglu, Sevsen; Cifci, Egemen; Ozulku, Mehmet; 0000-0002-7613-2240; 30581327; AAI-8932-2021
Background: Few data is available concerning the association between peripheral arterial disease (PAD) and red cell distribution width (RDW). In this study, we analyzed the relationship between RDW and atherosclerosis of the vessels other than coronary arteries in patients who had undergone digital substraction angiography (DSA). Methods: This study included 730 patients who had undergone DSA. Patients were divided into two groups according to their angiographic images. The association between RDW and atherosclerosis of peripheral arteries was analyzed. The relationship between atherosclerosis and smoking, hypertension (HT), diabetes mellitus (DM), hs-CRP, hemoglobin, white blood cell (WBC), triglyceride, total cholesterol, HDL and LDL cholesterol levels was assessed. Results: Atherosclerosis was observed more common in male and patients with older age, HT, DM and smoking (p< 0.001). hs-CRP and WBC levels were both in significantly positive association with atherosclerosis (p< 0.05). However, there were no significant differences in the RDW levels, hemoglobin, triglyceride, total cholesterol, LDL and HDL cholesterol levels in the groups (p> 0.05). Conclusions: Our results seem to demonstrate that older age, male gender, HT, DM and smoking are powerful risk factors for PAD. In contrast to the previous reports, RDW levels are found not to be associated with atherosclerosis of peripheral arteries.
Radial Artery, Saphenous Vein versus Left Internal Thoracic Artery in Recurrent Ischemic Symptoms after Coronary Artery Bypass Graft Surgery
(2014) Gunday, Murat; Coskun, Isa; Ciftci, Ozgur; Ozulku, Mehmet; Tekindal, Mustafa Agah; Guven, Aytekin; Aslamaci, Sait; https://orcid.org/0000-0002-6463-6070; https://orcid.org/0000-0002-4060-7048; 25065278; A-7318-2017; U-9270-2018; AAJ-8546-2021
Background: The long-term results of coronary artery bypass surgery depend mostly on the type of the grafts. For a long time, it has been accepted that arterial grafts are superior to venous grafts. In this study, we evaluated the angiographic patency rates of arterial and venous grafts. Methods: The study took place between 2003 and 2013 in the Departments of Cardiovascular Surgery in Baskent University. The study included 52 patients with recurrent ischemic symptoms (of total 2183 coronary artery bypass surgery patients) following coronary artery bypass surgery. The patients were evaluated by control angiography during over mid- and long-term postoperative period (mean, 75.25 +/- 35.15 months). Based on the angiographic findings, the grafts were divided into 3 groups: severe stenosis, moderate stenosis, and patent. Results: The preoperative demographics (age, gender, hypertension or diabetes mellitus) were similar in the three groups. The mean numbers of distal anastomoses were 3.27 +/- 0.89 (range 2-5), the degree of native coronary artery stenosis for radial artery anastomosis was 79.65 +/- 17.72, and the mean numbers of radial artery and saphenous vein grafts were 1.19 +/- 0.44 and 1.10 +/- 0.89, respectively. The patency rate was 80.77%for radial arteries, 63.2% for saphenous veins, and 82.4% for left internal thoracic arteries in the three groups. Conclusion: The internal thoracic artery graft was confirmed to be the best option for aorta-coronary bypass surgery, as it has the highest patency rate compared to the other grafts. Radial artery and saphenous vein patency rate were also seen to be similar in the long-term.
Recurrence of Primary Vascular Leiomyosarcoma Five Years after Initial Diagnosis in the Lower Extremity
(2018) Erinanc, Hilal; Ozulku, Mehmet; Terzi, Aysen; 0000-0003-1401-6356; 0000-0002-1225-1320; 29971175; AAL-1268-2021; F-7546-2013
Primary leiomyosarcomas of vascular origin are rare tumors. They frequently arise within the inferior vena cava; however, the peripheral vein was also affected. To date, only a few hundred cases have been reported in the world literature. Although it is an extremely aggressive tumor, the symptoms may be unspecific, especially in the lower extremities. In this report, we present a case of primary vascular leiomyosarcoma, arising from the short saphenous vein, with symptoms mimicking thrombus in the initial diagnosis. The diagnosis of leiomyosarcomas was confirmed by standard H&E staining and immunohistochemical staining. Recurrence of the tumor has been observed five years after surgical treatment. Due to its rarity, experience in the management of this type of tumor is limited. The mainstay of treatment for these tumors is complete surgical resection. The purpose of the presented case is to discuss the clinicopathological features and management options of this tumor, under the light of the most recent literatures.
Serum Uric Acid and Carotid Artery Intima Media Thickness in Patients with Masked Hypertension
(2014) Caliskan, Mustafa; Guven, Aytekin; Ciftcl, Ozgur; Ozulku, Mehmet; Gunday, Murat; Barutcu, Irfan; https://orcid.org/0000-0002-6463-6070; 25181917; AAJ-8546-2021; A-7318-2017
Background Serum uric acid is related to hypertension and cardiovascular diseases. Masked hypertension is associated with an increase in cardiovascular risk. The aim of our study was to evaluate the serum uric acid level and its relationship with carotid intima-media thickness (IMT) in patients with masked hypertension. Subjects and methods A total of 114 untreated masked hypertension patients (62 men, 52 women; mean age 44.6 +/- 7.9 years) and 38 controls (20 men, 18 women; mean age 44.8 +/- 7 years) were included in the study. All patients underwent 24-hour ambulatory blood pressure. Serum uric acid and carotid IMT were measured. Results Serum uric acid was significantly higher in masked hypertension patients when compared to the control group (5.14 +/- 1.42 mg/dl, 4.84 +/- 1.45 mg/ dl, P=0.01). Masked hypertension patients had significantly higher carotid IMT than control subjects (0.58 +/- 0.09, 0.52 +/- 0.09, P < 0.001). The masked hypertension group was also divided into two groups according to the median value of the serum uric acid levels (median value: 5 mg/dl). Carotid IMT was significantly higher in patients with a higher uric acid when compared to those with a lower uric acid (P < 0.001). We also found that the serum uric acid level was a good predictor of increased carotid IMT at the receiver-operating characteristic curve. The area under the curve was 66% (95% confidence interval, 0.56-0.77), and the serum uric acid level was significantly predictive of a high carotid IMT (P=0.001). Conclusions Our data suggest that the uric acid levels were significantly higher in the masked hypertension group and elevated uric acid levels were associated with increased carotid IMT, indicating that elevated serum uric acid levels might contribute to the increase in cardiovascular risk in masked hypertension.