Tzevat Tefik
Istanbul University
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Featured researches published by Tzevat Tefik.
Journal of Endourology | 2013
Selcuk Erdem; Tzevat Tefik; Anar Mammadov; Feyyaz Ural; Tayfun Oktar; Halim Issever; I. Nane; Oner Sanli
PURPOSE To investigate the efficacy of self-retaining barbed suture (SRBS) on reducing renorrhaphy time and warm ischemia time (WIT) during laparoscopic partial nephrectomy (LPN), in comparison with conventional polyglactin suture. PATIENTS AND METHODS Between February 2008 and June 2012, 115 patients underwent LPN for renal tumors at our institution. Among them, the patients whose inner layer renorrhaphy was performed using SRBS (group 1, n=33) or polyglactin suture (group 2, n=33) were retrospectively identified from prospectively collected institutional laparoscopic database (unmatched comparison). Furthermore, 17 patients from each group were matched at a 1:1 ratio in terms of sex, age, body mass index, preoperative aspects and dimensions used for an anatomic (PADUA) classification scoring system, and operative approach (transperitoneoscopic/retroperitoneoscopic) to eliminate the effects of these variables on WIT (matched-pair comparison). Demographic, perioperative, and pathologic parameters were evaluated between groups in both unmatched and matched-pair comparison. RESULTS The perioperative parameters including inner layer renorrhaphy time, WIT, estimated blood loss, operative time, length of hospital stay, and complication rate were not statistically different between the two groups in the unmatched comparison. Median PADUA score (9 vs 8, P=0.006), median preoperative (4 cm vs 3.6 cm, P=0.049), and pathologic (4.5 cm vs 3.5 cm, P=0.009) tumor size, however, were significantly higher in group 1. In the matched-pair analysis, inner layer renorrhaphy time (350 sec vs 505 sec, P=0.004) and WIT (19 min vs 28 min, P=0.037) were significantly reduced with the use of SRBS in group 1 without a difference of median PADUA score (8 vs 8, P=1), median preoperative (3.8 cm vs 4 cm, P=0.959), and pathologic (4.2 cm vs 4 cm, P=0.284) tumor size. CONCLUSIONS The SRBS significantly reduced inner layer renorrhaphy time and WIT during LPN and may enable urologists to perform LPN in more challenging and larger tumors, in comparison with conventional polyglactin suture.
BJUI | 2013
Tzevat Tefik; Canan Kucukgergin; Oner Sanli; Tayfun Oktar; Sule Seckin; Cavit Ozsoy
To evaluate the relationship between manganese superoxide dismutase (MnSOD) Ile58Thr, catalase (CAT) C‐262T and myeloperoxidase (MPO) G‐463A gene polymorphisms and the susceptibility and clinicopathological characteristics of prostate cancer.
Urologic Oncology-seminars and Original Investigations | 2011
Oner Sanli; Canan Kucukgergin; Murat Gokpinar; Tzevat Tefik; I. Nane; Sule Seckin
OBJECTIVES To investigate the relationship between the distribution of endothelial NO synthase (eNOS4a/b) gene polymorphism and clinical features of prostate cancer (PCa). METHODS AND MATERIALS One hundred thirty-two patients with PCa (mean age 64.10 ± 7.23 years) and 158 healthy controls (mean age 62.50 ± 7.53 years) with normal serum total prostate specific antigen (PSA) levels (<4 ng/ml) and digital rectal examinations (DRE) were enrolled in this prospectively designed study. PCa patients were classified as clinical T1 and T2 stages (Group 1), clinical T3 and T4 stages without bone metastasis (Group 2), and patients with bone metastasis (Group 3). Genotypes (aa, bb, ab) for eNOS4a/b gene polymorphisms were identified by polymerase chain reaction analysis. Meanwhile, plasma nitrate and nitrite levels (NO(x)) were used to estimate the amounts of endogenous NO formation for both groups of patients. RESULTS Despite lack of statistically significant differences between PCa patients and the control group in terms of distribution of genotypes and frequency of alleles, plasma NO(x) levels were found to be significantly increased in PCa patients compared with controls. Meanwhile, there was no significant difference between the group of PCa patients with high and low grade tumors (Gleason score ≥ 7 vs. < 7) in terms of genotype (aa + ab genotypes or a-allele vs. bb genotype) distribution. However, bb genotype was observed to be present at a higher frequency (85.1% vs. 60%) in Group 1; whereas a-allele was more frequent in Group 2 (13.3% vs. 5.7%) and Group 3 (26.7 vs. 9.2). In addition, patients with a-allele had a 3.79-fold risk of having advanced disease and bone metastasis in comparison with bb genotype. Moreover, multivariable logistic regression analysis revealed that eNOS4a/b polymorphism and plasma NOx levels were predictive factors for developing bone metastasis and high stage disease after adjustment for age and BMI. CONCLUSIONS Our data did not reveal any relationship between any of these genotypes and the presence of PCa. However, the finding that PCa patients with bb genotype generally manifest localized disease and develop bone metastasis less frequently in comparison patients with a-allele may indicate an important role for this polymorphism in the molecular pathophysiology of PCa.
Archivio Italiano di Urologia e Andrologia | 2016
Salvatore Butticè; Antonio Simone Laganà; Giuseppe Mucciardi; Francesco Marson; Tzevat Tefik; Christopher Netsch; Salvatore Giovanni Vitale; Emre Sener; Rosa Pappalardo; Carlo Magno
OBJECTIVE Endometriosis is an estrogendependent disease. The incidence of urinary tract endometriosis (UE) increased during the last few years and, nowadays, it ranges from 0.3 to 12% of all women affected by the disease. The ureter is the second most common site affected. The ureteral endometriosis is classified in extrinsic and intrinsic. The aim of this study is to individuate the best treatments for each subset of ureteral endometriosis. MATERIALS AND METHODS 32 patients diagnosed with surgically treated UE were retrospectively reviewed. The patients were divided into 3 subsets (intrinsic UE, extrinsic UE with and without obstruction). The patients with intrinsic UE (n = 10) were treated with laser endoureterotomy. The patients with extrinsic UE (n = 22) were divided in two subsets with (n = 16) and without (n = 6) hydronephrosis. All the patients underwent ureteral stenting, and resection and reimplantation was performed in the first group, and when the mass was > 2.5 cm (n = 3) Boari flap was performed. Laparoscopic ureterolysis (shaving) was performed in the second group. RESULTS In the extrinsic subset of UE, we obtained an high therapeutic success (84%). Conversely, in the intrinsic subset there was a recurrence rate of the disease in 6/10 of the patients (60%). CONCLUSIONS Ureterolysis seems to be a good treatment in extrinsic UE without obstruction. Resection and reimplantation allows excellent results in the extrinsic UE with obstruction. In the intrinsic subset, the endoureterotomy approach is inadequate.
International Journal of Surgery Case Reports | 2012
Tzevat Tefik; Oner Sanli; Tayfun Oktar; Omer Baris Yucel; Yasemin Ozluk; Isin Kilicaslan
INTRODUCTION Achieving hemostasis in laparoscopic nephron sparing surgery (LNSS), a technically demanding procedure, is challenging. Absorbable hemostatic agents, such as oxidized regenerated cellulose (ORC) are frequently used for hemostasis in laparoscopic nephron sparing surgery. Retention of this material is a very rare situation. PRESENTATION OF THE CASE We are presenting a case of ORC granuloma after nephron sparing surgery for renal cell carcinoma (RCC) mimicking recurrent renal mass. A 50-year-old woman diagnosed with upper pole renal mass underwent laparoscopic nephron sparing surgery. Oxidized regenerated cellulose was used to achieve hemostasis for an oozing from the perirenal tissue. Resection confirmed RCC. Imaging at 6th month follow-up revealed a lesion with contrast enhancement at the location of the adrenal gland. Positron emission tomography suggested inflammation or metastasis. Histopathological evaluation of the mass revealed foreign body granuloma. DISCUSSION Laparoscopic nephron sparing surgery is becoming a standardized treatment of select renal tumors. Hemostatic agents, such as ORC, are frequently used to minimize complications in LNSS. In case of ORC application, which is completely absorbed in 8 weeks, to or to a location with close proximity to the primary resection site, surgical granuloma formation should be considered. However its use should not be discouraged and biopsy may be considered for definitive diagnosis. CONCLUSION Oxidized regenerated cellulose granuloma may mimic different entities such as including invasive carcinoma. Thus it is of utmost importance, if ORC was used during LNSS, the location and use of this material should be noted precisely.
Polish Journal of Radiology | 2016
Mesut Bulakci; Tzevat Tefik; Merve Gulbiz Kartal; Erhan Celenk; Oğuz Bülent Erol; Oner Sanli; Artur Salmaslioglu
Summary Background In this paper the clinical and radiological features of three cases with paratesticular fibrous pseudotumor were presented after a retrospective analysis of medical archives of our hospital. Case Report Each of the three cases had unilateral, multiple nodular lesions with smooth borders accompanied by a hydrocele. On sonographic examination, the lesions showed echogenicity similar to, or slightly lower than, the testis, and the two large lesions had posterior acoustic shadowing. Color Doppler ultrasound examination of two cases showed intralesional vascularity of mild-to-moderate degree. All lesions appeared hypointense compared to testicular tissue on T1W and T2W magnetic resonance images. Moderate-to-high enhancement was observed in the diffuse pattern after intravenous injection of contrast material. An intraoperative pathological examination was performed and local excision carried out in all three cases. Conclusions Fibrous pseudotumor is a rare benign paratesticular lesion, which can be confused with malignant masses. Imaging procedures play an important role in correct diagnosis. Unfamiliarity with imaging findings of paratesticular fibrous pseudotumor may eventuate in an unnecessary orchiectomy.
International Journal of Immunogenetics | 2015
Y. Seyhun; H.S. Ciftci; Cigdem Kekik; Meltem Karadeniz; Tzevat Tefik; I. Nane; Aydin Turkmen; Fatma Oguz; F. Aydin
Cytokines are essential for the control of the immune response as most of the immunosuppressive drugs target cytokine production or their action. The calcineurin inhibitors (CNIs) cyclosporine (CsA) and tacrolimus are immunosuppressive drugs widely used after renal transplantation to prevent allograft rejection. They are characterized by large interindividual variability in their pharmacokinetics; therefore, monitoring their blood concentrations is important to predict their optimal dosage following transplantation. Calcineurin inhibitors inhibit the phosphatase activity of calcineurin, thereby suppressing the production of other cytokines such as transforming growth factor (TGF‐β), tumour necrosis factor‐α (TNF‐α), interleukin (IL)‐6, IL‐2, and IL‐4. The aim of this study was to investigate the relationship between polymorphisms of cytokines and blood concentrations of CNIs in renal transplant patients. The study included 53 CsA‐treated renal transplant patients and 37 tacrolimus‐treated renal transplant patients. Cytokine polymorphisms were analysed using polymerase chain reaction (PCR) sequence‐specific primers with the cytokine CTS‐PCR‐sequence‐specific primers Tray Kit; University of Heidelberg. Blood concentrations of CNIs were determined with Cloned Enzyme Donor Immunoassay (CEDIA) method. Patients with TC genotype of TGF‐β at codon 10 had lower CsA blood concentrations than the TT and CC genotypes (P = 0.005) at 1 month in CsA treatment group. The ratio of blood concentration/dose of CsA for patients with TGF‐β1‐codon 10 TC genotype was lower than for patients with TT, CC genotypes, and the dose given to these patients was higher in the first month (P = 0.046). The ratio of blood concentration/dose of CsA for patients with IL‐2‐330 GG genotype was higher than for patients with GT, TT genotypes, and the dose given to these patients was lower at first month and sixth months (P = 0.043, P = 0.035 respectively). The tacrolimus blood concentrations were significantly higher in patients with the genotype GG of IL‐2‐330 (P = 0.012) at the third month. Patients who had the TC genotype TGF‐β codon 10 had lower CsA blood concentrations and this group had higher acute rejection (P = 0.033). These results suggest that the genotyping for TGF‐β‐codon 10, IL‐2‐330 and IL‐6‐174 polymorphisms may help individualized immunosuppressive dosage regiments.
Jsls-journal of The Society of Laparoendoscopic Surgeons | 2010
Oner Sanli; Tzevat Tefik; Mazhar Ortac; Meltem Karadeniz; Tayfun Oktar; I. Nane; Murat Tunc
With an experienced laparoscopic team of surgeons, laparoscopic nephrectomy may be performed safely.
Jsls-journal of The Society of Laparoendoscopic Surgeons | 2012
Oner Sanli; Selcuk Erdem; Tzevat Tefik; Omer Aytac; Omer Baris Yucel; Tayfun Oktar; Faruk Ozcan
Laparoscopic excision of local recurrent renal cell carcinoma appears to be a feasible technique in wellselected patients with low-volume mass not involving adjacent organs.
Journal of Minimal Access Surgery | 2016
Oner Sanli; Tzevat Tefik; Selcuk Erdem; Mazhar Ortac; Emre Salabas; Serkan Karakus; Baris Yucel; Abubekir Boyuk; Tayfun Oktar; Faruk Ozcan; Necdet Aras; Murat Tunc; I. Nane
Aim: To evaluate the laparoscopic operations performed in our department according to the modified Clavien classification system of complications. Materials and Methods: Between September, 2005 and February, 2014, a total of 1023 laparoscopic cases were performed. This period was divided into three terms (Terms 1, 2 and 3 consisting of 38, 32 and 32 months, respectively). According to the European Scoring System (ESS), easy (E), slightly difficult (SD), fairly difficult (FD), difficult (D), very difficult (VD) and extremely difficult (ED) cases were 35, 88, 170, 390, 203 and 137, respectively. The perioperative complications were evaluated based on the 3 time periods, with a specific emphasis on determining the learning curve according to the modified Clavien classification system of complications. Results: A total of 236 (23.1%) complications were observed according to the modified Clavien classification. The minor (Clavien I-II) and major (Clavien III, IV and V) complication rates were 20.5% (n = 210) and 2.4% (n = 26), respectively. Clavien I was the most frequently encountered type of complication (n = 120, %11.7). No significant difference was observed among all 3 time periods regarding total complication rates. The D cases had the highest complication rate compared to E, SD, FD, VD and ED cases among all three terms. The total number of complications increased significantly with increasing grade of technical difficulty according to the ESS. Conclusion: Complications encountered in our laparoscopic surgery experience were predominantly minor, and the rate of complications was not significantly increased during the learning curve. The present data can provide guidance and manage expectations for surgeons introducing laparoscopy into their practice.