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Dive into the research topics where Tayfun Oktar is active.

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Featured researches published by Tayfun Oktar.


The Journal of Urology | 2002

A Retrospective Review of 307 Men With Peyronie’s Disease

Ates Kadioglu; Ahmet Tefekli; Bulent Erol; Tayfun Oktar; Murat Tunc; Sedat Tellaloglu

PURPOSE We discuss the clinical appearance and natural outcome of Peyronies disease. MATERIALS AND METHODS During an 8-year period 307 men with Peyronies disease were evaluated, and clinical characteristics, risk (factors), penile deformities, erectile status and outcome were analyzed. RESULTS Mean patient age plus or minus standard deviation was 52.8 +/- 9.3 years (range 23 to 76). Penile deformity, pain on erection and palpable nodule were the most common (85%) presenting symptoms, usually in different combinations. The remaining 15% of men (mean age 59.4 +/- 6.5 years) were not aware of the penile deformity and were diagnosed during standard evaluation for erectile dysfunction. Dorsal (45.6%) and lateral (29.3%) were the most common curvatures. The degree of deformity was less than 30 degrees in 42.7% of patients, 31 to 60 degrees in 38.8% and greater than 60 degrees in 18.6%. At least 1 risk factor for systemic vascular disease was identified in 67.5% of patients, and hypercholesterolemia and diabetes were the most common. Patients with at least 1 risk factor had a significantly higher risk for severe penile deformity. Of the men 54.4% complained of erectile dysfunction and the probability of diminished erectile capacity was 86.7% in patients older than 60 years, with Peyronies disease for more than 12 months and at least 1 risk factor. Of 63 patients presenting with the acute phase of disease penile deformity deteriorated in 30.2%, did not change in 66.7% and resolved spontaneously in 3.2% without any treatment after a mean followup of 8.4 months. CONCLUSIONS Our data show that penile deformities are disabling (greater than 30 degrees) in 62.5% of cases. Risk factors, such as serum lipid abnormalities, diabetes and hypertension, seem to have significant impact on the severity of symptoms and outcome. Patients must be informed that Peyronies disease is progressive in 30.2% without treatment and spontaneous resolution is rare.


Urologia Internationalis | 2004

Urological and Surgical Complications in 362 Consecutive Living Related Donor Kidney Transplantations

Taner Koçak; I. Nane; Haluk Ander; Orhan Ziylan; Tayfun Oktar; Cavit Ozsoy

Objective: The aim of this study is to review retrospectively the surgical and urological complications encountered in 362 cases of living related donor kidney transplantations (LRDTs). Material and Methods: Between 1983 and 2002, 362 consecutive LRDTs were performed at our institution. The urological and surgical complications were determined in these cases. Results: Overall, urological and surgical complications were encountered in 57 (15.7%) of the renal transplants. Of the 362 patients, urological complications were detected in 29 of them (8.01%), including 5 urinary fistula (with 1 distal ureteral necrosis), 2 ureteric stenosis, 1 renal calculi, 8 symptomatic vesicoureteral reflux and 13 lymphocele requiring intervention. Vascular complications were developed in 5 patients such as renal vein thrombus in 1 and renal arterial stenosis in 4 cases. Wound infection was detected in 6 patients. Fourteen patients underwent surgical explorations due to perinephric hematoma during the early postoperative period. Renal allograft rupture due to accelerated rejection was developed in 2 cases. A lower segmental arterial injury occurred in 1 patient during the operation. Conclusion: LRDT is an important treatment alternative for patients with end-stage renal disease. Many complications may occur after renal transplantations. Our rate of complications is within the range of the current literature. After a modification of our surgical technique, as not dissecting the external iliac artery, the number of lymphoceles has decreased dramatically and with using ureteric stents, we detected a significant decrease in urinary complication rates.


International Journal of Impotence Research | 2004

Incidentally diagnosed Peyronie's disease in men presenting with erectile dysfunction

Ates Kadioglu; Tayfun Oktar; Engin Kandirali; Muammer Kendirci; Oner Sanli; Cavit Ozsoy

The aim of this study was to analyze characteristics of patients with Peyronies disease (PD) diagnosed during a standart evaluation for erectile dysfunction (ED) and compare them with patients presenting with the classical complaints of PD. During a 10-y period, a total of 448 patients were evaluated at our two outpatient clinics, directed by the same author (AK). They were divided into two groups: group I consisted of patients, who presented with only ED and were unaware of their penile deformity, and group II consisted of patients with the classical features of the disease. The clinical characteristics, penile deformities, erectile status and the presence of comorbidities were determined in the two groups. Of 448 Peyronies patients, 16% (n=71) were detected during diagnostic work-up for ED. In this group of patients, ED was the presenting symptom for a mean period of 31.3±9.7 months. The mean age of men was 57.54±8.75 and 52.21±10.27 y in groups I and II, respectively (P=0.0001). The mean degree of deformity was 31.5±12.66° in group I and 41.16±19.14° in group II (P=0.0001). In group I (n=71), 69% (n=49) of the patients had a poor erectile response to the combined injection and stimulation (CIS) test. Also, in this group, the mean degrees of deformity in CIS-positive and -negative patients were 27.05±12.50 and 33.80±12.03°, respectively (P=0.033). Diabetes mellitus (40%) was the leading comorbidity in group I, while at least one comorbidity was observed in 73% of the cases (P=0.001). A remarkable percent of Peyronies patients (16%) were detected during a standard evaluation for ED. This study analyzed, for the first time, the frequency and the characteristics of incidentally diagnosed Peyronies patients who presented with only ED. Our data indicate that one should always consider the possibility of PD in older patients with diabetes, presenting with only ED.


The Journal of Urology | 2006

The Impact of Late Presentation of Posterior Urethral Valves on Bladder and Renal Function

Orhan Ziylan; Tayfun Oktar; Haluk Ander; Esat Korgali; Hasan Rodoplu; Taner Koçak

PURPOSE We retrospectively reviewed the records of patients with late presentation of PUVs, and compared bladder and renal function to that in patients with an early diagnosis of PUVs. MATERIALS AND METHODS We retrospectively reviewed the charts of 36 males (mean age at diagnosis 8.8 years, range 5 to 14) with late presentation of PUVs who were treated at our institution between 1986 and 2004. Of these patients 20 had undergone urodynamic evaluation during followup (mean age 10.65 years, range 5 to 23). We chose as controls 19 age matched children with PUVs who were diagnosed and treated before age 5 years and underwent urodynamic evaluation during followup (mean age at urodynamic evaluation 8.52 years, range 6 to 15). Urodynamic parameters were compared between the 2 patient groups. Renal function in the late presenting cases was also compared to controls. RESULTS The most common symptoms at presentation were diurnal enuresis (17 patients, 47.2%) poor stream (7, 19.4%) and urinary retention (5, 13.9%). Overall, urodynamic bladder abnormalities were detected in 17 of 20 patients (85%), detrusor overactivity in 3 (15%), significant post-void residual in 9 (45%) and bladder capacity greater than expected for age in 9 (45%). No significant difference in bladder capacity, compliance or post-void residual was demonstrated between the late presenting and control groups. Only detrusor overactivity was significantly lower in the late presenting group (p = 0.013). After a mean followup of 67.03 months age specific creatinine levels were increased in 13 of 27 patients (48.1%), including 7 (25.9%) with ESRD. Renal function was significantly impaired in the late presenting group compared to controls (48.1% vs 13.7%, p = 0.001). CONCLUSIONS We found a significantly lower rate of detrusor overactivity (15%) in patients with late presenting PUVs. Comparison of urodynamic parameters between the early and late presenting groups did not reveal any significant difference. This similar pattern of bladder dysfunction, independent of age at relief of obstruction, may indicate a common pathophysiological etiology for bladder dysfunction in all patients with PUVs. Also, renal function was significantly impaired in the late presenting group in this series.


Journal of Endourology | 2013

The Use of Self-Retaining Barbed Suture for Inner Layer Renorrhaphy Significantly Reduces Warm Ischemia Time in Laparoscopic Partial Nephrectomy: Outcomes of a Matched-Pair Analysis

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

Manganese superoxide dismutase Ile58Thr, catalase C-262T and myeloperoxidase G-463A gene polymorphisms in patients with prostate cancer: relation to advanced and metastatic disease

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.


Journal of Pediatric Urology | 2013

Urinary nerve growth factor in children with overactive bladder: A promising, noninvasive and objective biomarker

Tayfun Oktar; Taner Koçak; Yıldız Öner-İyidoğan; Selcuk Erdem; Muhammed Seyithanoğlu; Orhan Ziylan; Hikmet Koçak

OBJECTIVE This prospective study was designed to determine urinary nerve growth factor (NGF) levels in children with overactive bladder (OAB), and to evaluate whether this factor can be used as a biomarker for diagnosis and monitoring treatment outcome. PATIENTS AND METHODS Urinary NGF levels were determined in 40 children with OAB and in a control group of 20 children with no urinary symptoms. Urine samples were collected from the patients prior to and at 3 and 6 months after the beginning of treatment. The total NGF levels (pg/mL) were further normalized to the concentration of urinary creatinine (NGF/Cr level). RESULTS Overall, both NGF and NGF/Cr levels were significantly higher at the beginning of the study. Mean NGF levels were 30.75 ± 8.35 and 9.75 ± 2.11 pg/ml (p = 0.023) and mean NGF/Cr levels were 0.53 ± 0.14 and 0.16 ± 0.04 (p = 0.022) in patients and controls, respectively. After 6 months of therapy, the NGF/Cr level was significantly reduced to almost control levels (0.16 ± 0.02, p = 0.047). CONCLUSION NGF and NGF/Cr levels were significantly higher in children with OAB than controls at initial evaluation. Furthermore, the NGF/Cr level was significantly reduced following 6 months of therapy. NGF and NGF/Cr levels show promise as reliable biomarkers for OAB diagnosis and to monitor therapy in the pediatric age group.


Journal of Pediatric Urology | 2013

Radiation-free percutaneous nephrostomy performed on neonates, infants, and preschool-age children

Ahmet Ali Sancaktutar; Yaşar Bozkurt; Adnan Tüfek; Haluk Söylemez; Hakan Önder; Murat Atar; Necmettin Penbegül; Mehmet Nuri Bodakci; Namık Kemal Hatipoglu; Tayfun Oktar

AIM The aim of this study was to evaluate the effectiveness and safety of high-frequency linear probe ultrasonographic (US) guidance percutaneous nephrostomy (PN) in terms of diagnostic and therapeutic approach in preschool-age children with urological problems. MATERIALS AND METHODS PN was performed on 40 kidneys in 33 patients (13 girls, 20 boys) aged 3 days - 7 years (mean 4.1 years). All procedures were performed with US guidance utilizing a Shimadzu SDU 2200 Xplus 5-10 mHz probe. Complete blood count, urinalysis, bladder urine culture, blood urea, and creatinine values were obtained before PN placement on the same day. Urine cultures were obtained by nephrostomy tube and compared to bladder urine culture. RESULTS PN procedures were technically successful in 39 kidney units (97.5%). Two major complications were macroscopic hematuria requiring blood transfusions (1 case) and sepsis (1 case). Minor complications were displacement of the catheter (4), urinary tract infection (4), urine extravasation (1), early dislocation of the catheter (1). In three cases, the catheter was replaced. Analysis of bladder urine showed that 13 patients (39.4%) had positive cultures, but analysis of PN urine showed that 25 patients (78.1%) had positive cultures. CONCLUSIONS PN is an easy, safe and efficient diagnostic and therapeutic procedure with few complications even in preschool-age children. The antibiotic regimen should be revised in order to avoid sepsis and urinary tract infection.


Urology | 2008

Positional changes in voiding dynamics of children with non-neurogenic bladder dysfunction.

Nihat Uluocak; Tayfun Oktar; Ömer Acar; Olga İncesu; Orhan Ziylan; Unal Erkorkmaz

OBJECTIVES To investigate the effect of certain positions on voiding dynamics in children with non-neurogenic bladder dysfunction. METHODS A total of 29 patients (10 male, 19 female) with non-neurogenic overactive bladder were enrolled. None of the patients had voiding phase dysfunction. Male patients were told to urinate in three positions (sitting, squatting, standing). Female patients did not void while standing. During voiding, maximum urinary flow rate (Qmax), detrusor pressure at maximal flow (Pdet-Qmax), and intra-abdominal pressure at maximal flow (Pabd-Qmax) were recorded. After voiding in one position, the bladder was re-distended. The same procedures were repeated for the three different positions. Then patients were told to perform three drinking-voiding cycles without the catheter in place. After recording Qmax, residual urine was measured with ultrasonography. The differences between these parameters were analyzed. RESULTS The mean (+/- standard deviation) patient age was 11.10 +/- 2.94 years (range, 6-16 years). In girls, the mean Pdet-Qmax value in the sitting and squatting positions was 43.11 +/- 16.74 cm H(2)O and 35.21 +/- 10.67 cm H(2)O, respectively (P = .028). Girls voided with a significantly higher Qmax in sitting and squatting positions than boys, regardless of the presence of a catheter. The mean Pdet-Qmax value in the squatting position was 59.20 +/- 20.45 cm H(2)O in boys and 35.21 +/- 10.67 cm H(2)O in girls. The presence of a catheter significantly lowered mean maximal urinary flow rates in sitting and squatting positions. CONCLUSIONS This is the first study to demonstrate the effect of voiding positions on pressure flow study results in children. Our results show that voiding dynamics are influenced by different voiding positions in children with non-neurogenic bladder dysfunction.


Journal of Pediatric Urology | 2013

Residual valve and stricture after posterior urethral valve ablation: How to evaluate?

Tayfun Oktar; Emre Salabas; Ömer Acar; Arda Atar; I. Nane; Haluk Ander; Orhan Ziylan

OBJECTIVE To investigate the clinical and radiological parameters of posterior urethral valve (PUV) patients with residual valve or strictures after primary valve ablation. PATIENTS AND METHODS A total of 127 PUV patients were treated in our clinic between 1986 and 2009. We retrospectively reviewed the records of 101 patients, who had at least 1 year of follow-up data, regarding the presence of valve remnants or urethral strictures after PUV ablation. RESULTS A total of 21 patients (20.8%) underwent repeat-urethroscopy and, of these, residual valve leaflets or stricture were detected in 10 patients (10/101, 9.9%). In 2 of these 10 (20%), the urethra had been found to be normal on the first voiding cystourethrogram following ablation. However, these two boys underwent re-urethroscopy due to persistent vesicoureteral reflux in one and persistent hydroureteronephrosis in the other, and valve remnants were detected. The remaining 8 cases had radiological signs consistent with persistent infravesical obstruction in the early period. Obstruction was due to urethral stricture and residual valve remnants in 2 and 6 cases, respectively. CONCLUSIONS There was clinical suspicion of residual valve in about 20% of the cases and in half of these the urethra was found to be normal on urethroscopy. The possible presence of residual valve remnants after primary valve ablation should be confirmed by careful clinical, radiological and endoscopic evaluation.

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