Querying the significance of patient position during computerized tomography on the reliability of pre-percutaneous nephrolithotomy planning.

BACKGROUND: Computerized tomography (CT) is considered indispensable in percutaneous nephrolithotomy (PCNL) planning. We aimed to define the reliability of pre-PCNL CT for planning renal access by assessing renal positional changes between supine and prone CTs. SUBJECTS AND METHODS: CT urographies (CTU) of 30 consecutive patients were reviewed for distances upper pole (UP)-diaphragm, UP-diaphragm attachment, renal pelvis (RP)-lateral body wall, RP- posterior body wall, and lower pole (LP)- anterior-superior iliac spine (ASIS). The posterior and lateral renal axes angles were also calculated. RESULTS: The most consistent overall movement in transition from prone to supine was backward rotation, as demonstrated by a decrease in distance UP-posterior body wall (p = 0.010) and increase in the posterior renal angle (p < 0.0001). This finding correlated with the patient's body mass index (BMI) (p = 0.029). The left kidney was more mobile than the right one, moving significantly for five of the measured parameters compared to the right kidney which moved significantly for only two parameters. The UP-diaphragm distance of the left kidney correlated with age (p = 0.014), the RP-lateral wall distance correlated with previous abdominal surgery (p = 0.006), and the RP-posterior wall distance with BMI (p = 0.017). On the right, the UP-diaphragm distance correlated with gender (p = 0.002) and the lateral renal rotation was smaller (p = 0.046). CONCLUSIONS: Kidneys present significant mobility between supine and prone positions. CT assessment should be performed in the position expected during surgery and should be interpreted with caution, while a real-time imaging modality should be used in the operating room.

Long-Term Indwelling Tandem Polymeric Ureteral Stents for Benign Ureteral Obstruction.

Objective: To assess the outcome of tandem polymeric internal stents (TIS) for benign ureteral obstruction (BUO). Material and Methods: We conducted a retrospective study that included all consecutive patients treated for BUO by means of TIS in a single tertiary center. Stents were replaced routinely every 12 months or earlier, when indicated. The primary outcome was permanent stent failure, and the secondary outcomes included temporary failure, adverse events, and renal function status. Kaplan-Meier and regression analyses were used to estimate outcomes, and logistic regression was used to assess the association between clinical variables and outcomes. Results: Between July 2007 and July 2021, 26 patients (34 renal units) underwent a total of 141 stent replacements, with median follow-up of 2.6 years (interquartile range [IQR] 0.75-5). Retroperitoneal fibrosis was the leading cause of TIS placement (46%). Permanent failures occurred in 10 (29%) renal units, and the median time to permanent failure was 728 days (IQR 242-1532). There was no association between preoperative clinical variables and permanent failure. Temporary failure occurred in four renal units (12%), which were treated by nephrostomy and eventually returned to TIS. Urinary infection and kidney injury rates were one event for every four and eight replacements, respectively. There was no significant alteration in serum creatinine levels throughout the study (p = 0.18). Conclusion: TIS provides long-term relief for patients with BUO and offers a safe and effective solution for urinary diversion, while avoiding the need for external tubes.

Performance of CellDetect for detection of bladder cancer: Comparison with urine cytology and UroVysion.

OBJECTIVE: To compare the performance of CellDetect, a new biomarker with urine cytology and UroVysiontechnology for bladder cancer detection. PATIENTS AND METHODS: We performed an IRB approved prospective, blinded single center study in patients on routine surveillance for nonmuscle invasive bladder cancer and those scheduled for transurethral resection of bladder tumor or radical cystectomy. Patients with bladder catheters, neobladder, ileal conduit, urinary stones, or those with upper tract carcinoma were excluded from the study. Voided urine sample was collected from the participants and each sample was divided into three equal aliquots (CellDetect, Urine cytology and Urovysion). Pathology of the operative specimen was considered the gold standard to which the three markers were compared. RESULTS: The study group included 93 patients with median age was 68 years (range: 34-92 years) with male to female ratio of 12:1. Pathologic evaluation revealed malignancy in 43 cases (46%) of whom 81% had previous history of urothelial bladder cancer. Among all studied markers CellDetect exhibited the best performance followed by urine cytology and U-FISH with diagnostic odds ratio of 4.33, 3.85, and 2.5 respectively. The overall sensitivity, specificity, negative predictive value, and positive predictive value for this test were 84%, 80%, 88%, and 74% respectively. The advantage of this new biomarker was observed both in high grade and low-grade cases. CONCLUSIONS: This study demonstrates the advantage of CellDetect as a urine-based assay to detect urothelial bladder cancer over urine cytology and U-FISH test. The high performance was maintained across all cancer grades and stages without compromising the assay specificity. Additional studies are required to test if it can be a noninvasive alternative to cystoscopy.