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Featured researches published by Nejat Tansu.


The Journal of Urology | 2001

THE EFFICACY OF EXTRACORPOREAL SHOCK WAVE LITHOTRIPSY FOR ISOLATED LOWER POLE CALCULI COMPARED WITH ISOLATED MIDDLE AND UPPER CALICEAL CALCULI

Can Öbek; Bulent Onal; Koray Kantay; Mehmet Kalkan; Veli Yalcin; ARMAˇGAN Öner; Vural Solok; Nejat Tansu

PURPOSE We assess the efficacy of extracorporeal shock wave lithotripsy monotherapy for isolated lower pole nephrolithiasis, and compare it to that for isolated middle and upper caliceal calculi. MATERIALS AND METHODS We treated 714 renal units in 687 patients with isolated caliceal stones using a Lithostar lithotriptor (Siemens Medical Systems, Erlangen, Germany). The stones were localized in the lower, mid and upper calices in 455, 104 and 128 patients, respectively. Stone load was recorded in cm.2. Patients were stratified into 3 groups based on stone burden. The energy and shock waves, use of anesthesia, number of treatment sessions, auxiliary measures and complications were noted. Patients were evaluated with intravenous urogram or plain film of kidneys, ureters and bladder, and ultrasonography when stone-free, or clinically significant residual fragment status, including nonobstructive and noninfectious insignificant fragments 4 mm. or less, was noted at the fluoroscopic control 2 to 4 weeks after the last session. Final clinically significant residual fragment decision was made 10 to 12 weeks after the last session. Extracorporeal shock wave lithotripsy was considered a failure if no fragmentation was noted after session 3 and continued if fragmentation was noted. Results regarding caliceal localization were compared. RESULTS Complete data were available on 591 renal units. Auxiliary procedures were used in 81 (14%) units before treatment. Anesthesia was given to 101 (17%) patients. The mean number of shock waves and energy used were 2,022 and 17.4 kV., respectively. The difference in shock wave, energy and treatment rate among 3 caliceal locations reached statistical significance only for energy delivered to the lower and upper calices. The effectiveness quotient of extracorporeal shock wave lithotripsy was 36%, 46% and 41% for lower, middle and upper pole stone disease, respectively (p = 0.4). There was a highly significant correlation between stone-free and re-treatment rates, and stone burden. The overall stone-free rate was 66%, and 63%, 73% and 71% for lower, middle and upper caliceal stones, respectively (p = 0.1). For the group with stones greater than 2 cm.2 overall stone-free rate decreased to 49%, and 53%, 60% and 23% in lower, middle and upper caliceal locations, respectively. Overall, extracorporeal shock wave lithotripsy monotherapy failed in 46 (7.7%) renal units. Steinstrasse developed in 39 (6.5%) patients who were then treated with repeat lithotripsy. CONCLUSIONS Extracorporeal shock wave lithotripsy appears to be successful for management of isolated caliceal stone disease. Treatment efficacy was not significantly different among stones localized in lower, middle and upper poles. We recommend it as the primary treatment of choice for stones less than 2.0 cm.2 in all caliceal locations. Treatment should be individualized for management of caliceal stones greater than 2.0 cm.2 until large prospective randomized trials comparing shock wave lithotripsy and percutaneous nephrolithotomy are available.


Urology | 2008

Evaluation of the Effects of Relationships Between Main Spatial Lower Pole Calyceal Anatomic Factors on the Success of Shock-Wave Lithotripsy in Patients with Lower Pole Kidney Stones

Tayfun Sahinkanat; Hasan Cetin Ekerbicer; Bulent Onal; Nejat Tansu; Sefa Resim; Sinharib Citgez; Armağan Öner

OBJECTIVES To evaluate the effects of lower pole calyceal anatomy on lower pole stone clearance after shock-wave lithotripsy (SWL). METHODS A total of 133 patients who had single lower pole radio-opaque stones treated with SWL alone and who became stone-free or had clinically insignificant residual fragments (CIRF) were included in the study. Pre-shock-wave lithotripsy intravenous urograms were used to determine the lower pole infundibular width and length, lower pole infundibulopelvic (LPIP) angle, caliceal pelvic height (CPH), and lower infundibular length-to-width ratio. In addition, to evaluate the relationship between LPIP and CPH, a more simple alternative measurement instead of LPIP angle, called the parenchyma-to-ureter distance (PUD), was suggested. The correlation between LPIP and PUD was then examined, and a good correlation was found between these values (P <0.000, r = 0.64). The PUD/CPH ratio was also calculated. RESULTS The stone-free rate was 62%. According to the cutoff points, the lower infundibular length-to-width ratio and PUD/CPH ratio were different in the stone-free and CIRF groups by univariate analysis but not by multivariate analysis. CONCLUSIONS None of the anatomic factors had a statistically significant effect in predicting the success of SWL in patients with lower pole stones. Nevertheless, evaluation of relationships between lower pole anatomic factors may offer some help in reaching a more accurate interpretation of lower pole stone clearance after SWL.


Journal of Endourology | 2001

Extracorporeal Shockwave Lithotripsy for Stones in Abnormal Urinary Tracts: Analysis of Results and Comparison with Normal Urinary Tracts

Oktay Demirkesen; Ozgur Yaycioglu; Bulent Onal; Mehmet Kalkan; Nejat Tansu; Veli Yalcin; Ali Riza Kural; Vural Solok

PURPOSE We reviewed our experience with SWL for stones in abnormal urinary tracts and compared the results with those in normal urinary tracts. PATIENTS AND METHODS The study group was composed of 2566 renal units (RU) treated on the Siemens Lithostar lithotripter at our SWL unit whose treatment and follow-up at 10 to 12 weeks were completed. Sixty-eight RUs (2.7%) belonged to 52 patients who had congenital upper urinary tract abnormalities. Logistic regression analysis was performed to analyze the impact of age, stone size, location, and the type of abnormality on the outcome of the SWL in the abnormal RU. The student t-, chi-square, and Fishers exact tests were used for the comparison of stone load, number of treatment sessions, catheter placement, and success rates of the patients with normal and abnormal RU. Results of long-term follow-up for available patients (38 RU; 56%) were also evaluated. RESULTS Age, stone load, stone location, and the type of abnormality did not have a statistically significant impact on the outcome of SWL for abnormal RU. The average stone load was 2.1 +/- 2.8 cm2 in the abnormal and 1.4 +/- 1.3 cm2 in the normal RU. Thus, the stone load was significantly higher in the abnormal RU (P < 0.05). In the abnormal group, 56% of the RU became stone free, 37% had nonobstructive and noninfectious clinically insignificant residual fragments < or = 4 mm (CIRF), and SWL failed in 7%. In the normal group, 78% of the RU became stone-free, 18.5% had CIRF, and SWL failed in 4%. There was no significant difference in the success rates in the groups if success was defined as stone free and CIRF together (P > 0.05). However, there was significant a difference when stone-free, CIRF, and failure rates were evaluated separately (P < 0.05). Recurrence, regrowth, and retreatment rates in abnormal RU were 50%, 37%, and 34%, respectively. CONCLUSIONS Although the fragmentation rates were similar, clearance of the fragments was hampered in abnormal urinary tracts. Thus, especially for large stones, other endourologic treatment options should be considered. High recurrence and regrowth rates warrant careful monitoring and consideration for medical treatment during follow-up.


BJUI | 2013

Nomogram and scoring system for predicting stone‐free status after extracorporeal shock wave lithotripsy in children with urolithiasis

Bulent Onal; Nejat Tansu; Oktay Demirkesen; Veli Yalcin; Lin Huang; Hiep T. Nguyen; Bartley G. Cilento; Ahmet Erozenci

Extracorporeal shock wave lithotripsy is often considered to be the first‐line treatment method for the majority of urinary tract stone disease in children. The stone clearance rate in children treated with ESWL is higher than that in adults. Recently, nomograms for several diseases, e.g. for specific cancers, have been developed and validated in large patient populations. They have become very popular predictive tools that provide the most objective, evidence‐based, and individualized risk estimation. These nomograms have gained acceptance as useful guides in clinical practice for use by physicians and patients. In adults, a nomogram has been created to predict stone‐free outcome after ESWL; however, to our knowledge none has been developed for children with urolithiasis. This is the first study‐generated nomogram table and scoring system for predicting the stone‐free rate after ESWL in children. This predictive tool could be useful for clinicians in counselling the parents of children with urolithiasis and in recommending treatment.


Urology | 2012

Predictive factors and management of steinstrasse after shock wave lithotripsy in pediatric urolithiasis--a multivariate analysis study.

Bulent Onal; Sinharib Citgez; Nejat Tansu; Cetin Demirdag; Cagatay Dogan; Burcu Gonul; Oktay Demirkesen; Can Öbek; Ahmet Erozenci

OBJECTIVE To define the predictive factors for the formation of steinstrasse (SS) after shock wave lithotripsy (SWL) and determine the treatment strategies for this complication in pediatric urolithiasis. METHODS We retrospectively reviewed the data of 341 renal units (RUs) treated with SWL for urolithiasis. The stone location, stone burden, auxiliary procedures, energy level, and number of shock waves were recorded. Statistical analysis was performed to detect the predictive factors for the formation of SS. In addition, the treatment of children with SS was evaluated. RESULTS The mean age of the children was 8.31 years (range 1-17). Episodes of SS developed in 26 RUs (7.6%). Of the 26 RUs, 20 (77%) were localized in the lower, 5 (19%) in the upper, and 1 (4%) in multiple locations in the ureter. The stone burden was the only statistically significant factor predicting the formation of SS on logistic regression analysis (P = .001). Of the 26 RUs, 17 (65.4%) were successfully managed by repeat SWL monotherapy, 4 (15.4%) were managed with ureteroscopy after failure of SWL, 1 (3.8%) was managed by ureteroscopy monotherapy, and 4 (15.4%) were monitored with conservative management with antispasmodic drug plus hydration therapy. The mean number of SWL sessions was 1.72. CONCLUSION The incidence of SS development in children after SWL treatment was similar to that in adult series. Our results suggest that the stone burden is a significant predictive factor for the development of SS after SWL in pediatric urolithiasis. Most children with SS could be easily and safely treated by repeat SWL.


Central European Journal of Urology 1\/2010 | 2015

Does ureteral stenting matter for stone size? A retrospectıve analyses of 1361 extracorporeal shock wave lithotripsy patients.

Burak Özkan; Cagatay Dogan; Gulce Ecem Can; Nejat Tansu; Ahmet Erozenci; Bulent Onal

Introduction The aim of our study was to determine the efficacy of ureteral stents for extracorporeal shock wave lithotripsy (SWL) treatment of pelvis renalis stones and to compare the results and complications in stented and non-stented patients. Material and methods Between 1995 and 2011, 1361 patients with pelvis renalis stones were treated with SWL. Patients were subdivided into three groups according to stone burden: ≤1 cm2 (group 1; n = 514), 1.1 to 2 cm2 (group 2; n = 530) and >2 cm2 (group 3; n = 317). Each group was divided into subgroups of patients who did and did not undergo ureteral stent implantation before SWL treatment. The efficacy of treatment was evaluated by determining the effectiveness quotient (EQ). Statistical analysis was performed by chi-square, Fishers exact and Mann-Whitney U tests. Results Of the 514, 530 and 317 patients in groups 1, 2 and 3 respectively, 30 (6%), 44 (8%) and 104 (33%) patients underwent auxiliary stent implantation. Steinstrasse rates did not differ significantly between stented and non-stented patients in each group. The EQ was calculated as 62%, 33% and 70% respectively in non-stented, stented and totally for group 1. This ratio calculated as 58%, 25% and 63% for group 2 and 62%, 26% and 47% for group 3. Stone-free rates were significantly higher for non-stented than for stented patients in groups 2 and 3. Conclusions Stone free rates are significantly higher in non-stented than in stented patients with pelvis renalis stones >1 cm2, whereas steinstrasse rates are not affected.


Journal of Endourology | 2017

Does Previous Open Renal Stone Surgery Affect the Outcome of Extracorporeal Shockwave Lithotripsy Treatment in Adults with Renal Stones

Mehmet Hamza Gultekin; Fethi Ahmet Türegün; Burak Özkan; Beril Tulu; Gamze Gul Gulec; Nejat Tansu; Cetin Demirdag; Pınar Kendigelen; Ahmet Erozenci; Bulent Onal

PURPOSE To evaluate the effects of previous ipsilateral open renal stone surgery (ORSS) on outcomes of extracorporeal shockwave lithotripsy (SWL) in adults with renal stones. MATERIALS AND METHODS A total of 2097 renal units with renal stones underwent SWL treatment at our institution between March 1997 and February 2013. One thousand eight hundred thirty-nine (87.7%) of these had no history of ORSS and were categorized as group 1, and 258 (12.3%) patients having history of ipsilateral ORSS were categorized as group 2. Characteristics of patients, stone and treatment, stone-free, and complications rates were documented in detail and compared in each group. These groups were also subclassified into four subgroups according to the stone location. RESULTS The stone-free rates were statistically higher in group 1 than group 2 (73.2% and 61.6%, respectively). There were no differences between groups regarding the complications and steinstrasse. The stone-free rate of SWL for stones located at lower calix has significant difference according to groups 1 and 2 (64% vs 48.4%, p = 0.001). Logistic regression analysis showed that history of ORSS increased SWL failure rate 1.39 times. CONCLUSION Overall stone-free rates after SWL treatment was found to be significantly lower in patients with the history of ORSS than in patients without, and this finding was significantly prominent for lower calix stones. We believe that retrograde intrarenal surgery or mini- /micro-percutaneous nephrolithotripsy, despite its possible difficulties in accessing due to anatomical changes, might be a good alternative for SWL.


Urology | 2006

Efficacy of extracorporeal shock wave lithotripsy for isolated lower caliceal stones in children compared with stones in other renal locations

Oktay Demirkesen; Bulent Onal; Nejat Tansu; Ramazan Altintaş; Veli Yalcin; Armağan Öner


The Journal of Urology | 2004

THE IMPACT OF CALICEAL PELVIC ANATOMY ON STONE CLEARANCE AFTER SHOCK WAVE LITHOTRIPSY FOR PEDIATRIC LOWER POLE STONES

Bulent Onal; Oktay Demirkesen; Nejat Tansu; Mehmet Kalkan; Ramazan Altintaş; Veli Yalcin


Journal of Endourology | 1999

Extracorporeal shockwave lithotripsy in the pediatric population.

Oktay Demirkesen; Nejat Tansu; Ozgur Yaycioglu; Bulent Onal; Veli Yalcin; Vural Solok

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