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    Effectiveness of Brain Protection With Histidine-Tryptophan-Ketoglutarate Solutions
    (Forum Multimedia Publishing, Llc, 2020) Oguz, Sonay; Asgun, Halil F.; Buyuk, Basak
    Background: Tissue-protective solutions increase resistance of cells to ischemic conditions. Especially in carotid and aortic arch surgeries where the brain perfusion is at risk, these solutions may be beneficial to prevent ischemic brain damage. This study was designed to demonstrate the effectiveness of histidine-tryptophan-ketoglutarate (HTK) solution in increasing resistance of brain tissue to ischemic conditions. Methods: Three separate randomized groups were created, each consisting of eight rabbits. The groups were called the ischemia, HTK and sham groups, respectively. In the ischemia group, temporary brain ischemia was created for 15 minutes by placing clamps on the bilateral subclavian and common carotid arteries. Then the clamps were removed, and the brain was reperfused for 30 minutes. In the HTK group, HTK solution was sent to the brain through the internal carotid artery before the same ischemia-reperfusion protocol was applied. Histopathological analyses using a visual scoring system to assess the degree of ischemic changes and the apoptotic cell index by TUNEL test were performed in all brain tissue samples. Results: Apoptotic cell indices of the HTK (20.6%) and sham (17.8%) groups were lower than the ischemia group (56.8%) (P < .05). Statistically significant differences were detected between all groups in categorical scores (P < .05). Conclusions: It was shown that less ischemic damage occurs in the brain tissue with the use of HTK solution, and it may be a candidate approach to prevent the brain from ischemic insults during cerebrovascular surgery. Further studies are required to demonstrate its exact effectiveness, in terms of dose, duration, and temperature.
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    Histopathological changes in myocardial tissue due to coronary venous hypertension
    (Termedia Publishing House Ltd, 2023) Aksit, Ercan; Buyuk, Barak; Oguz, Sonay
    Introduction: In chronic venous insufficiency (CVI), an increase in venous pressure causes the passage of intravascular blood cells and molecules into the surrounding tissues and induces histopathological changes in the lower extremities, leading to increased pigmentation in the legs, ulceration, and tissue loss to various degrees. This study aimed to investigate whether an increase in venous pressure in the coronary veins can lead to the aforemen-tioned histopathological changes. Material and methods: Twenty-four New Zealand rabbits were divided into the following three groups: experimental model of coronary venous hyper-tension (CVH) (n = 8), sham group (n = 8), and control group (n = 8). After 21 days postoperatively, tissue samples from each group were compared for perivascular inflammation, erythrocyte extravasation, macrophage infiltra-tion, and hemosiderin deposits by histopathological scoring under a light microscope. Matrix metalloproteinase-2 (MMP-2) activation was evaluated using immunohistochemical staining. Results: In the CVH group, hemosiderin accumulation was significantly high-er than in the sham and control groups (1.0 (1.0-3.0), 0.0 (0.0-1.0), 0.0 (0.0- 0.0); p < 0.001). Immunohistochemically, in the CVH group, MMP-2 levels were significantly higher than in the sham and control groups (2.0 (1.0-3.0), 0.0 (0.0-1.0), 0.0 (0.0-0.0); p < 0.001). Conclusions: This experimental study showed for the first time the histo-pathological and immunohistochemical changes in myocardial tissue, simi-lar to those observed in CVI, as a result of increased coronary venous pres-sure due to coronary vein ligation. Further studies are needed to understand the clinical implications of these results.
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    Our mid-and long-term results of endovenous radiofrequency ablation in great saphenous vein insufficiency
    (Bayrakol Medical Publisher, 2024) Oguz, Sonay
    Aim: Venous insufficiency may occur due to problems in the return of blood to the heart and reverse flows. Endovascular procedures have emerged as an alternative to classical open surgery in treatment. In this study, we aimed to examine the mid- and long-term results of our radiofrequency ablation (RF) applications, which is an endovascular method. Material and Method: In our study, we included 193 patients who underwent RF in our clinic between June 2017 and March 2022. All patients underwent ablation with an RF catheter by entering the great saphenous vein (GSV) at the appropriate level under local tumescent anesthesia and under Dopplerultrasound guidance. Postoperative follow-up of the patients and Dopplerultrasound controls at the 1st, 6th, 12th and 24th months were performed, and GSV patency and reflux conditions were recorded. Results: 133 patients were female (68.9%) and 60 patients were male (31.1%). The age range was 22-82 (mean: 52). It was determined that GSV recanalisation and reflux developed in 6 patients (3.1%) at the 1 -month follow-up, in 9 patients (4.6%) at the 6th month, and in 11 patients (5.6%) at the 12th and 24th months. Discussion: RF method is a feasible method with low complications, high patient comfort and success in suitable patients. However, recanalization and recurrence still occur. To achieve higher success rates, the reasons underlying recanalization and recurrence should be examined.
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    Systemic capillary leak syndrome during cardiac surgery
    (Baycinar Medical Publ-Baycinar Tibbi Yayincilik, 2023) Asgun, Halil Fatih; Oguz, Sonay
    Systemic capillary leak syndrome is defined as excessive fluid and protein extravasation caused by microvascular hyperpermeability. It is a very rare condition, and may occur during or after any surgery without preceding symptoms or a suggestive history. It has been reported in pediatric cardiac surgery patients, and is not expected in adults. In this article, we present a 75-year-old female case of severe systemic capillary leak developed during coronary artery bypass grafting combined with dual valve replacement. To the best of our knowledge, this is the first adult case in the literature having an acute attack of systemic capillary leak syndrome during cardiac surgery.
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    The efficacy of a wearable hemodialysis with tentative equipment in chronic renal failure
    (E-Century Publishing Corp, 2020) Oguz, Sonay; Asgun, Halil Fatih; Bakirdogen, Serkan; Cakir, Dilek Ulker
    Objective: The aim of this study was to find an effective and simple method by which outpatient hemodialysis can be performed using diffusion and ultrafiltration methods with different procedures on a model. Methods: A solution containing high-level urea and creatinine similar to the blood values of patients with chronic renal failure was used, with the expectation of clearing it as in hemodialysis using a model with the designed system. The product values at the beginning and end of the process were determined, and the cleaning rates were calculated. Results: The clearance rates obtained in the serum were 79.2% for urea and 93.7% for creatinine. Greater than 65% clearance rates were detected in all products except calcium and magnesium. Statistical significance was found in all products (P < 0.05) except magnesium (P = 0.065). Conclusions: Using this method, we achieved a clearance rate greater than the desired clearance rates (65%) in hemodialysis.