Researcher:
Oktar, Tayfun

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Doctor

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Tayfun

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Oktar

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Oktar, Tayfun

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2020 - 20239

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    Renal, bladder and sexual outcomes in adult men with history of posterior urethral valves treated in childhood
    (Elsevier Science Inc, 2021) Çetin, Bilal; Dönmez, Muhammet İrfan; Erdem, Selçuk; Ziylan, Orhan; N/A; Oktar, Tayfun; Doctor; N/A; Koç University Hospital; N/A
    OBJECTIVE To determine the adulthood outcomes of bladder, kidney, and sexual functions of posterior urethral valve (PUV) patients. MATERIALS and METHODS The records of patients who were treated for PUV between 1980, and 2001 and aged >= 18 years by the end of 2019 were retrospectively reviewed. Patients with complete adulthood data were included in the study. Renal, bladder, and sexual functions were assessed. Adulthood uroflowmetry results of 22 patients were also evaluated. RESULTS Thirty-nine patients with complete adulthood data out of 89 were included. The median followup time was 22.7 years (15-33 years). Median age at initial surgery for PUV was 36 months (1-168 months), and median age at last follow-up was 26 years (18-46 years). Lower urinary tract dysfunction was noted in 15 (38%) patients. In 22 patients (56%) with uroflowmetric analyses, median values of Q(max), voided volume, and post voiding residual urine volume were 20.5 mL/sec (7-43 mL/sec), 389 mL (154-1750 mL), and 18.5 mL (range 0-190 mL), respectively. Nineteen patients (48.7%) had normal glomerular filtration rate, 2 patients (5.1%) had chronic kidney disease, and the remaining 18 patients (46.1%) had end stage renal disease, 14 (35.9%) of whom underwent renal transplantation. Thirty-two patients (82%) had sexual function evaluation, none of which reported erectile dysfunction. However, 4 patients (12.5%) reported slow ejaculation. Five patients fathered a child whereas infertility was observed in 2 patients. CONCLUSION After 2 decades, glomerular filtration rate was normal almost in half of the PUV patients while lower urinary tract dysfunction was detected in 38%. Furthermore, erectile dysfunction was rare.
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    Urinary HSP70 can predict the indication of surgery in unilateral ureteropelvic junction obstruction
    (Springer, 2022) Kucukgergin, Canan; Donmez, M. Irfan; Ozkuvanci, Unsal; Yilmaz, Alev; Yildirim, Zeynep Yuruk; Erdem, Selcuk; Seckin, Sule; Ziylan, Orhan; N/A; Oktar, Tayfun; Doctor; N/A; Koç University Hospital; N/A
    Background Distinguishing hydronephrosis that requires surgical intervention is a clinical challenge. The aim of this study is to determine the level of urinary heat shock protein 70 (HSP70) in children who required surgery for ureteropelvic junction obstruction and its potential use as a biomarker for prediction of surgery in children with isolated unilateral hydronephrosis. Methods The data of 43 children with ureteropelvic junction obstruction who underwent pyeloplasty, 25 patients with non-obstructive dilation (NOD) and 30 healthy children (control group) were collected prospectively for this study. Preoperative and postoperative urinary HSP70/Cr levels were also analyzed in 30 children in the pyeloplasty group who had available follow-up information. HSP70 levels were assessed using ELISA. Results The median age of the pyeloplasty group was 13 months (IQR 7-36 months), NOD group was 42.5 months (IQR 16-73) and it was 36 months (IQR 24-47.5) in the control group. The mean preoperative urinary HSP70/Cr was significantly higher in the pyeloplasty group when compared to controls as well as the NOD group (150.6 pg/mgCr vs. 65.0 pg/mgCr and vs. 64.7 pg/mgCr, p < 0.001 and p < 0.001, respectively). The urinary HSP70 levels significantly decreased in the postoperative period (151.5 vs 79.5, p < 0.001). Using the cutoff value of 94.7 pg/mgCr, the sensitivity and specificity of urinary HSP70 for predicting the risk of surgical intervention were 69.7% and 68%, respectively (AUC = 0.689). Conclusion Urinary HSP70 may be used as an adjunct tool to clinical parameters to identify patients that would require surgery due to ureteropelvic junction obstruction.
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    Recurrent cervical cancer case with sacral metastasis
    (BMJ Publishing Group, 2022) N/A; Taşkıran, Çağatay; Vatansever, Doğan; Giray, Burak; Dönmez, Emin Erhan; Deveci, Mehmet Ali; Oktar, Tayfun; Arvas, Macit; Faculty Member; Faculty Member; Faculty Member; Researcher; Faculty Member; Doctor; Doctor; School of Medicine; School of Medicine; School of Medicine; School of Medicine; School of Medicine; N/A; N/A; N/A; N/A; N/A; N/A; N/A; Koç University Hospital; Koç University Hospital; 134190; 193687; 316087; 334646; 206311; N/A; N/A
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    Lower urinary tract reconstruction for ectopic ureterocele: what happens in the long-term follow-up?
    (W.B. Saunders, 2022) Selvi, Ismail; Kart, Mücahit; Dönmez, M. İrfan; Çetin, Bilal; Boyuk, Abubekir; Ziylan, Orhan; Oktar, Tayfun; Doctor; Koç University Hospital
    Background: We aimed to analyze the long-term clinical and lower urinary tract function outcomes in children with duplex system ectopic ureterocele who underwent ureteroneocystostomy and ureterocelectomy. Methods: Fifty-one patients (28 females, 23 males) who underwent a series of surgical interventions including lower urinary tract reconstruction in childhood for duplex system ectopic ureterocele in our center between 1998 and 2019, were retrospectively reviewed. The demographic and clinical data, surgical history, and the indication for ureterocelectomy were noted. Lower urinary tract dysfunction (LUTD) status was assessed through dysfunctional voiding symptom scores (DVSS) and uroflowmetry in all patients at the last follow-up. The clinical outcomes, and LUTD were evaluated. Results: At the last visit at a mean follow-up of 117.18 ± 57.87 months after ureterocelectomy, ipsilateral persistent lower pole VUR was detected in 5.6% (3/54 renal units, 2 females and 1 male) of the cases, who were treated using the subureteric injection. Abnormal DVSS (median 11, range 9–15) was detected in 27.4% (14/51 pts) of the patients. Out of these, 57.1% (8/14 pts) had storage symptoms, 35.7% (5/14 pts) had voiding symptoms, and 7.1% (1/14 pts) had both storage and voiding symptoms while 71.4%(10/14 pts) had abnormal uroflowmetry findings (plateau shaped flow curve in 2, staccato shaped curve with sustained EMG activity in 3, tower shaped curve in 2, interrupted shaped curve in 3 patients). Five patients had elevated residual volume. Anticholinergics were administered to six patients who had overactive bladder symptoms. In addition, two girls required open bladder neck reconstruction due to stress incontinence caused by bladder neck insufficiency. Conclusions: Our findings showed that clinical success was achieved using the lower urinary tract reconstruction with no need for re-operation in 90.2% of patients with duplex system ectopic ureterocele. However, LUTD was present in 27.4% of our patients in the long-term follow-up. Therefore, LUTD should be carefully assessed in the long-term follow-up of these patients.
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    Does pre-fellowship experience alter success rates of endoscopic treatment of vesicoureteral reflux during pediatric urology fellowship?
    (Elsevier Sci Ltd, 2022) Selvi, Ismail; Canbaz, Furkan Adem; Donmez, M. Irfan; Ozkuvanci, Unsal; Cetin, Bilal; Kart, Mucahit; Ziylan, Orhan; N/A; Oktar, Tayfun; Doctor; N/A; Koç Universitiy Hospital; N/A
    Introduction Learning curve is a well-known factor that affects the success rate of endoscopic injection for ves-icoureteral reflux (VUR). Objective To our knowledge, the significance of pre-fellowship training has not been studied. In the present study, our aim was to investigate the effect of pre -fellowship training on the endoscopic treatment success rates of pediatric urology fellows.Design A total of 78 patients aged 2-16 years (132 renal units) who underwent subureteric injection for the treatment of primary VUR by four pediatric urology fellows between 2014 and 2020 were retrospectively evaluated. Fellows were grouped into two as expe-rienced and non-experienced according to the presence of pre-fellowship experience (defined as a minimum of 20 procedures). Patients in both groups were divided into two subgroups as non-dilating (grade I-II) and dilating VUR (grade III-V). Also, the change in success rate throughout the fellowship was analyzed. HIT or Double HIT method was used in all interventions.Results Experienced fellows carried out subureteric injec-tion in 54 (40.9%) renal units while non-experienced fellows performed in 78 (59.1%). There was no suc-cess rate difference between experienced and non -experienced fellow groups in non-dilating VUR (100% vs. 88%, respectively p = 0.268), whereas the success rate of the experienced group was signifi-cantly higher in dilated VUR (78.9% vs. 50.9%, p = 0.006). Moreover, the amount of material used in the treatment of non-dilating VUR were similar between two fellow groups (0.6 ml vs. 0.6 ml, p = 0.500), while experienced group achieved higher success rates in dilating VUR by statistically significant less amount of injected volume (0.7 ml vs. 0.9 ml, p = 0.026).Overall complete VUR reso-lution rates were similar throughout the fellowship period in the experienced fellows (81.5% vs. 88.9%, p = 0.444), while it significantly increased in the non-experienced group implicating the completion of the learning curve (51.3% vs. 74.4%, p = 0.035).Discussion There has been no published reports on the effect of pre-fellowship experience on subureteric injection success. While many researchers reported on the importance of learning curve, various studies assessed the effect of injected volume on success rate implicating contradictory results. Furthermore, others indicated that the ideal technique providing accurate needle placement and obtaining proper depth during injection which is associated with sur-gical experience is more important than the injected volume in achieving success.Conclusion Our results implicate that similar success rates in non-dilating VUR can be achieved regardless of previous subureteric injection training. However, higher failure rates may be expected when the procedures are performed by non-experienced pediatric urology fellows at the beginning of their fellowship in dilating VUR.
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    Urodynamically proven lower urinary tract dysfunction in children after COVID-19: A case series
    (Wiley, 2022) Selvi, Ismail; Donmez, Muhammet Irfan; Ziylan, Orhan; N/A; Oktar, Tayfun; Doctor; N/A; Koç University Hospital; N/A
    Case Since the declaration of COVID-19 as a pandemic, other unexpected symptoms related to the infection besides the respiratory system have been reported. Although a few case reports have revealed that adult patients with COVID-19 also complained of urinary frequency and nocturia, the exact pathophysiology is still unclear. In this case series, we present three children aged 14 to 17 years with urodynamically proven lower urinary tract dysfunction (LUTD) following COVID-19. Outcome None of the patients had constipation or bowel disorder before the diagnosis of COVID-19. In addition, neurological examination and related imaging revealed no signs of etiological factors. The median time from diagnosis of COVID-19 infection to the onset of lower urinary tract symptoms was 3 months. Incomplete bladder emptying/urinary retention supported by increased bladder compliance, high post-micturition residual urine volumes, and absence of detrusor pressure increase during the voiding phase in the pressure flow study (acontractile detrusor in two patients and hypocontractile detrusor in one patient) were observed. Conclusion We observed that LUTD (eg, incomplete bladder emptying, urinary retention) can be prominent some time after the diagnosis of COVID-19. Even though psychogenic or neurogenic causes may not be excluded completely, clinicians should be aware of a recent COVID-19 infection in children with sudden-onset LUTD.
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    Urinary biomarkers can identify the need for pyeloplasty in presence of supranormal differential renal function in antenatally diagnosed unilateral hydronephrosis
    (Elsevier, 2022) Yucel, Omer Baris; Donmez, M. Irfan; Kucukgergin, Canan; Ziylan, Orhan; Seckin, Sule; N/A; Oktar, Tayfun; Doctor; N/A; Koç University Hospital; N/A
    Introduction Decision for surgery can be challenging in children with AH (Antenatal Hydronephrosis) especially in the setting of supranormal differential renal function (SnDRF). Objective Aim of this study is to investigate whether IP-10 (interferon gamma-induced protein 10), MCP-1 (monocyte chemotactic protein-1), NGAL (neutrophil gelatinase-associated lipocalin), CA 19-9 (carbohydrate antigen 19-9), and KIM-1 (kidney injury molecule-1) can identify the need for pyeloplasty in presence of SnDRF in antenatally diagnosed unilateral hydronephrosis. Study design A prospectively collected urinary biomarker database was used for the study. There was a total of 53 patients in the AH group. Nineteen children with no history of AH and a normal urinary ultrasonography were taken as controls. Patients with initial ipsilateral DRF (Differential Renal Function) over 50% were included in the SnDRF group while the remaining were named as non-SnDRF. Patients that didn't undergo surgery were classified as non-obstructive dilation (NOD) in both groups. Results Pyeloplasty was performed in 6/20 patients in SnDRF group, and in 19/33 patients in non-SnDRF group. Biomarker levels in the pyeloplasty and NOD groups were not affected by the presence or absence of SnDRF (p = 1.00, for both). Urinary NGAL, and CA 19-9 could determine the need for surgery in SnDRF group with 83% and 100% sensitivity, 86% and 79% specificity, respectively whereas urinary IP-10 and KIM-1 could with 84% and 83% sensitivity, 57% and 71% specificity, respectively. Urinary MCP-1 could differentiate patients who underwent surgery with 83% sensitivity and 50% specificity in SnDRF groups. Conclusion Our results showed that biomarker levels were not affected whether the kidney has SnDRF. Furthermore, in patients with SnDRF, NGAL and CA 19-9 appear to better estimate requirement for surgical correction before deterioration of renal function.
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    Maintenance biofeedback therapy for dysfunctional voiding: does every child need it?
    (Wiley, 2023) Donmez, Muhammet Irfan; Selvi, Ismail; Dereli, Elif; Ozgur, Kerime; Ziylan, Orhan; N/A; Oktar, Tayfun; Doctor; N/A; Koç University Hospital; N/A
    Objectives The aim of the present study is to analyze the long-term clinical outcomes in children who were treated with biofeedback therapy (BF) for dysfunctional voiding (DV) and to determine the need for maintenance of BF due to clinical relapse. Methods Files of children with DV who underwent BF between 2013 and 2020 were retrospectively reviewed. Patients with neurological or anatomical problems were excluded. A total of 64 patients (52 girls, 12 boys) with a mean age of 8.89 +/- 2.48 years who completed the initial BF sessions were included in the study. The demographic and clinical data, dysfunctional voiding symptom scores (DVSS), and uroflowmetry parameters were recorded before and after the initial BF sessions. Clinical success was regarded as the cessation of electromyography activity as well as concurrent resolution of lower urinary tract symptoms and improvement in uroflowmetry parameters. After the initial BF sessions, children who had initial success showed DV relapse at any time during follow-up received the maintenance BF sessions. Therefore, the patients with successful initial BF were divided into two groups: the group that needed maintenance BF, and the group which required no maintenance BF. Results Clinical success was achieved in 48 (75.0%) of 64 children following a median of 6 sessions (range 2-8). At the follow-up, 10 (20.8%) out of 48 patients showed symptom relapse at a median of 8 months (range 2-24 months). After a median of 3.5 maintenance BF sessions (range 1-6), clinical success was observed in all patients. Both groups showed a significant DVSS decrease after initial BF, however, those who needed maintenance had significantly higher DVSS (6.80 +/- 2.53 vs. 3.61 +/- 1.12, p < 0.001). At admission, DVSS <17.5 (odds ratio [OR]: 4.31, p = 0.025) and post-voiding residual volume as a percentage of estimated bladder capacity for age <28.9 (OR: 5.00, p = 0.009) were found as the predictive factors for initial BF success. The need for maintenance BF was 2.56-fold higher with a DVSS above 5.5 after initial BF sessions. Conclusions Our results show that despite a clinical success rate of 75% after the initial BF, relapse can be seen within 2 years in approximately 20% of the patients. Nevertheless, maintenance of BF may provide clinical success in all patients. Relatively higher DVSS after initial BF can be used as a predictor of the need for maintenance BF.
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    PublicationOpen Access
    Bladder Pain Syndrome (Interstitial Cystitis) Consensus 2019: the report of the Turkish Continence Society Bladder Pain Syndrome/Interstitial Cystitis Working Group
    (Galenos Yayınevi, 2020) Koçak, Taner; Tarhan, Fatih; Tefik, Tzevat; Acar, Ömer; Tarcan, Tufan; Oktar, Tayfun; Faculty Member; Other; School of Medicine; Koç University Hospital; 237530; 173289; N/A
    Bladder pain syndrome is an important chronic pain syndrome which seriously reduces the patients' quality of life. It is a diagnosis of exclusion. It is defined as a clinical diagnosis composed of chronic (>6 months) pain/pressure/discomfort that is primarly perceived from the bladder and/or pelvis, and accompanied by urgency and/or frequency of urination. Throughout this paper, the definition, characteristic features, diagnostic tests and attempts, interpretation of the findings and the different treatment algorithms suggested by different organizations will be discussed. / Mesane ağrısı sendromu, hastaların yaşam kalitesini ciddi şekilde azaltan önemli bir kronik ağrı sendromudur. Bir dışlama tanısıdır. Öncelikle, mesane ve/veya pelviste hissedilen ve sıkışma ve/veya pollakürinin de eşlik ettiği, kronik (>6 ay) tarzda, ağrı/basınç/rahatsızlık hissi olarak kendini gösteren klinik bir tablodur. Bu yazıda tanımı, karakteristik özellikleri, tanı testleri ve girişimleri, bulguların yorumlanması ve farklı kuruluşların önerdiği farklı tedavi algoritmaları tartışılacaktır.