Mehmet Yazici - Academia.edu (original) (raw)

Papers by Mehmet Yazici

Research paper thumbnail of Reliability of the Grading System for Voiding Cystourethrograms in the Management of Vesicoureteral Reflux: An Interrater Comparison

Advances in Urology, 2016

Aim. Vesicoureteral reflux (VUR) is one of the most common conditions seen in pediatric urology. ... more Aim. Vesicoureteral reflux (VUR) is one of the most common conditions seen in pediatric urology. Fortunately, there are many treatment options for this disorder. The grading system for VUR varies among doctors, and the literature on its reliability is sparse. Here, we assessed the effectiveness of the current VUR grading system.Methods. A series of 40 voiding cystourethrogram (VCUG) studies were selected. Four pediatric urologists (PU) and four pediatric radiologists (PR) independently graded each VCUG and then agreed on a uniform interpretation. For statistical analysis the intraclass correlation coefficient (ICC) was applied to assess interrater agreement.Results. ICC values ranging from 0.82 to 0.88 reflected the strong reliability of VCUG for grading cases of VUR among pediatric urologists and radiologists as separate groups, and the reliability between the two groups was also good, as indicated by an ICC of 0.89. Despite the high ICC, disagreement existed between raters; the lo...

Research paper thumbnail of The effect of bladder diverticula on bladder function: an Experimental study in rabbits

Journal of Pediatric Surgery, 2016

This study aims to evaluate the effect of bladder diverticula (BD) on bladder function using a ra... more This study aims to evaluate the effect of bladder diverticula (BD) on bladder function using a rabbit model, based on urodynamic findings. Methods: A total of 32 New Zealand white rabbits were randomly assigned to four groups: (1) sham surgery; (2) a single, 1-cm-diameter BD; (3) a single, large, 3-cm-diameter BD; and (4) four (multi) 1-cm-diameter BD. Urodynamic evaluations were performed preoperatively, and 1 week and 1 month postoperatively, to measure the postmicturition residual (PMR), maximum bladder capacity (MBC), filling and voiding detrusor pressure (Pdet), compliance, and unstable detrusor contractions. At the end of the study, the animals were sacrificed and assessed for pathologic evaluation and stone formation. Results: In groups 3 and 4, the rabbits all had PMR. At 30 days postsurgery, the MBC was found to be 28% and 31% lower than the reference range in groups 3 and 4 and compliance was decreased (p b 0.05). Further, the filling Pdet was significantly higher for large and multiple BD than in the 1-cm diverticula or sham groups (6.33 ± 1.73, 4 ± 1.26, p = 0.0001). Groups 3 (62%) and 4 (50%) had unstable detrusor contractions. There was also a muscular/collagen ratio increase in the large and multiple BD groups. Four rabbits in the large group and one rabbit in the multiple BD group exhibited stone formation. Conclusions: Large or multiple BD can alter bladder storage and emptying, and can decrease the capacity of the bladder and reduce its elasticity. Large or multiple bladder diverticula can lead to involuntary contractions, causing dysfunctional voiding.

Research paper thumbnail of Current radiological techniques used to evaluate unilateral partial ureteral obstruction: an experimental rabbit study

International Urology and Nephrology, 2015

group underwent Ulm-Miller surgery to create UPJO, whereas the left kidneys of nine rabbits from ... more group underwent Ulm-Miller surgery to create UPJO, whereas the left kidneys of nine rabbits from the second group underwent sham surgery. A pressure flow study (Whitaker's test) was done during postoperative week 6. Based on the Whitaker test, the DU, DRS, and MRU findings were compared. The number of apoptotic renal cells was counted after death. Result The Whitaker test run during postoperative week 6 revealed obstructions in 15 rabbits from group 1; the nine rabbits of the sham group had no obstructions. Sensitivity and specificity of DRS were 93.3 and 88.8 %, respectively, and those of MRU were 93.3 and 88.8 %, respectively. The postoperative mean RI values were significantly higher than the preoperative values, associated with sensitivity of 86.6 % and specificity of 77.5 % for detecting UPJO. DRS, MRU, and RI could not predict UPJO in one (8 %), one (8 %), and two (16 %) kidneys, respectively. Likelihood ratio (LR) was 8.4 for MRU and scintigraphy, while for RI, LR was 3.9. Pathology specimens revealed that all kidneys with UPJO underwent apoptosis, and the number of apoptotic cells was significantly higher on the UPJOcreated side than on the contralateral and in the sham group (p < 0.05). No test predicted all apoptosis related to UPJO. Conclusion The RI, DRS, and DMRU results correlated with the pressure flow results for detecting UPJO. No single radiological technique predicted all initial UPJO-created kidneys that concluded with apoptosis. Further studies are required to seek with better methods for diagnosing an obstruction or to define a combination of radiological techniques aiding in the management decision.

Research paper thumbnail of Case Report of a Man With Sertoli Cell Only, Transverse Testicular Ectopia, and External Auditory Canal Atresia

Urology Case Reports, 2015

Transverse testicular ectopia (TTE) is an uncommon congenital anomaly, reported mostly as pediatr... more Transverse testicular ectopia (TTE) is an uncommon congenital anomaly, reported mostly as pediatric case reports. Herewith we report a 43-year old man presenting with sertoli cell only, Transverse testicular ectopia and external auditory canal atresia.

Research paper thumbnail of Coin Ingestion in Children: Which Size Is More Risky?

Journal of Laparoendoscopic & Advanced Surgical Techniques, 2009

Aim: Because of economic inflation, different-sized coins are in circulation in our country. The ... more Aim: Because of economic inflation, different-sized coins are in circulation in our country. The coin ingestion and retention in the esophagus are common problems in childhood. We evaluated the patients with coins retained in the esophagus and the impact of the size of the coins on lodgment. Patients and Methods: Sixty-two children with a history of coin ingestion and a chest X-ray with retained coin in the esophagus were evaluated. Patients' age, sex, type of the ingested coin, and localization of coin were recorded. The size of all coins was measured. All coins were removed either directly with a Magill forceps or with the aid of an esophagoscope from the esophagus under general anaesthesia. Results: There were 27 male and 35 female patients with coin lodgment (median age, 4 years; range, 1-13). Forty-five patients (73%) ingested a coin with a diameter between 23.45 and 26.00 mm. In the remaining 17 patients (27%), the coins had a diameter between 17.00 and 20.90 mm or between 26.85 and 28.00 mm. Fifty coins were at the upper esophagus, eight coins were in the middle esophagus, and 4 patients had a coin in the distal esophagus. There was a positive correlation between the diameter of coin and age of the patient (r ϭ 0.415 and P Ͻ 0.001). Conclusions: Coin ingestion is rather common among childhood and its treatment may require an endoscopic approach. Most retained coins had a diameter between 23.45 and 26.00 mm. We think we could redesign our coins so that they would either be too big to ingest or so small they would always pass spontaneously.

Research paper thumbnail of Reliability of the Grading System for Voiding Cystourethrograms in the Management of Vesicoureteral Reflux: An Interrater Comparison

Advances in Urology, 2016

Aim. Vesicoureteral reflux (VUR) is one of the most common conditions seen in pediatric urology. ... more Aim. Vesicoureteral reflux (VUR) is one of the most common conditions seen in pediatric urology. Fortunately, there are many treatment options for this disorder. The grading system for VUR varies among doctors, and the literature on its reliability is sparse. Here, we assessed the effectiveness of the current VUR grading system.Methods. A series of 40 voiding cystourethrogram (VCUG) studies were selected. Four pediatric urologists (PU) and four pediatric radiologists (PR) independently graded each VCUG and then agreed on a uniform interpretation. For statistical analysis the intraclass correlation coefficient (ICC) was applied to assess interrater agreement.Results. ICC values ranging from 0.82 to 0.88 reflected the strong reliability of VCUG for grading cases of VUR among pediatric urologists and radiologists as separate groups, and the reliability between the two groups was also good, as indicated by an ICC of 0.89. Despite the high ICC, disagreement existed between raters; the lo...

Research paper thumbnail of The effect of bladder diverticula on bladder function: an Experimental study in rabbits

Journal of Pediatric Surgery, 2016

This study aims to evaluate the effect of bladder diverticula (BD) on bladder function using a ra... more This study aims to evaluate the effect of bladder diverticula (BD) on bladder function using a rabbit model, based on urodynamic findings. Methods: A total of 32 New Zealand white rabbits were randomly assigned to four groups: (1) sham surgery; (2) a single, 1-cm-diameter BD; (3) a single, large, 3-cm-diameter BD; and (4) four (multi) 1-cm-diameter BD. Urodynamic evaluations were performed preoperatively, and 1 week and 1 month postoperatively, to measure the postmicturition residual (PMR), maximum bladder capacity (MBC), filling and voiding detrusor pressure (Pdet), compliance, and unstable detrusor contractions. At the end of the study, the animals were sacrificed and assessed for pathologic evaluation and stone formation. Results: In groups 3 and 4, the rabbits all had PMR. At 30 days postsurgery, the MBC was found to be 28% and 31% lower than the reference range in groups 3 and 4 and compliance was decreased (p b 0.05). Further, the filling Pdet was significantly higher for large and multiple BD than in the 1-cm diverticula or sham groups (6.33 ± 1.73, 4 ± 1.26, p = 0.0001). Groups 3 (62%) and 4 (50%) had unstable detrusor contractions. There was also a muscular/collagen ratio increase in the large and multiple BD groups. Four rabbits in the large group and one rabbit in the multiple BD group exhibited stone formation. Conclusions: Large or multiple BD can alter bladder storage and emptying, and can decrease the capacity of the bladder and reduce its elasticity. Large or multiple bladder diverticula can lead to involuntary contractions, causing dysfunctional voiding.

Research paper thumbnail of Current radiological techniques used to evaluate unilateral partial ureteral obstruction: an experimental rabbit study

International Urology and Nephrology, 2015

group underwent Ulm-Miller surgery to create UPJO, whereas the left kidneys of nine rabbits from ... more group underwent Ulm-Miller surgery to create UPJO, whereas the left kidneys of nine rabbits from the second group underwent sham surgery. A pressure flow study (Whitaker's test) was done during postoperative week 6. Based on the Whitaker test, the DU, DRS, and MRU findings were compared. The number of apoptotic renal cells was counted after death. Result The Whitaker test run during postoperative week 6 revealed obstructions in 15 rabbits from group 1; the nine rabbits of the sham group had no obstructions. Sensitivity and specificity of DRS were 93.3 and 88.8 %, respectively, and those of MRU were 93.3 and 88.8 %, respectively. The postoperative mean RI values were significantly higher than the preoperative values, associated with sensitivity of 86.6 % and specificity of 77.5 % for detecting UPJO. DRS, MRU, and RI could not predict UPJO in one (8 %), one (8 %), and two (16 %) kidneys, respectively. Likelihood ratio (LR) was 8.4 for MRU and scintigraphy, while for RI, LR was 3.9. Pathology specimens revealed that all kidneys with UPJO underwent apoptosis, and the number of apoptotic cells was significantly higher on the UPJOcreated side than on the contralateral and in the sham group (p < 0.05). No test predicted all apoptosis related to UPJO. Conclusion The RI, DRS, and DMRU results correlated with the pressure flow results for detecting UPJO. No single radiological technique predicted all initial UPJO-created kidneys that concluded with apoptosis. Further studies are required to seek with better methods for diagnosing an obstruction or to define a combination of radiological techniques aiding in the management decision.

Research paper thumbnail of Case Report of a Man With Sertoli Cell Only, Transverse Testicular Ectopia, and External Auditory Canal Atresia

Urology Case Reports, 2015

Transverse testicular ectopia (TTE) is an uncommon congenital anomaly, reported mostly as pediatr... more Transverse testicular ectopia (TTE) is an uncommon congenital anomaly, reported mostly as pediatric case reports. Herewith we report a 43-year old man presenting with sertoli cell only, Transverse testicular ectopia and external auditory canal atresia.

Research paper thumbnail of Coin Ingestion in Children: Which Size Is More Risky?

Journal of Laparoendoscopic & Advanced Surgical Techniques, 2009

Aim: Because of economic inflation, different-sized coins are in circulation in our country. The ... more Aim: Because of economic inflation, different-sized coins are in circulation in our country. The coin ingestion and retention in the esophagus are common problems in childhood. We evaluated the patients with coins retained in the esophagus and the impact of the size of the coins on lodgment. Patients and Methods: Sixty-two children with a history of coin ingestion and a chest X-ray with retained coin in the esophagus were evaluated. Patients' age, sex, type of the ingested coin, and localization of coin were recorded. The size of all coins was measured. All coins were removed either directly with a Magill forceps or with the aid of an esophagoscope from the esophagus under general anaesthesia. Results: There were 27 male and 35 female patients with coin lodgment (median age, 4 years; range, 1-13). Forty-five patients (73%) ingested a coin with a diameter between 23.45 and 26.00 mm. In the remaining 17 patients (27%), the coins had a diameter between 17.00 and 20.90 mm or between 26.85 and 28.00 mm. Fifty coins were at the upper esophagus, eight coins were in the middle esophagus, and 4 patients had a coin in the distal esophagus. There was a positive correlation between the diameter of coin and age of the patient (r ϭ 0.415 and P Ͻ 0.001). Conclusions: Coin ingestion is rather common among childhood and its treatment may require an endoscopic approach. Most retained coins had a diameter between 23.45 and 26.00 mm. We think we could redesign our coins so that they would either be too big to ingest or so small they would always pass spontaneously.