Ender Ozden

Cystinuria, characterized by defective renal absorption of cystine causing recurrent nephrolithiasis, demands ongoing management. This study examines the effects of COVID-19-related disruptions in tiopronin availability on the clinical outcomes of pediatric cystinuria patients. This retrospective cohort study analyzed medical records of 11 pediatric patients with cystinuria, followed from 2001 to 2023. Patients were diagnosed using urine microscopy/biochemistry and stone composition analysis. Clinical outcomes, including renal function and stone status, were assessed using serial ultrasonographic evaluations and 24-hour urinary cystine measurements. At diagnosis, the median age was 13 months, and 63.6% were female. Acute kidney injury was observed in 36.4% of patients, with 27.3% requiring emergency dialysis. The interruption of tiopronin treatment led to significant renal function deterioration and increased stone burden, as evidenced by an increase in the median number of kidney stones from 2 (IQR: 1–3) to 4 (IQR: 2–5, p = 0.045) and a rise in 24-hour urinary cystine levels from 286 mg/1.73 m² (IQR: 82–552.5) to 434 mg/1.73 m² (IQR: 198–854, p = 0.043). Data prior to the interruption showed a median glomerular filtration rate (GFR) of 80.4 mL/min/1.73 m² and creatinine levels of 2.47 mg/dL. After resuming tiopronin, there was a notable improvement to a median GFR of 161 mL/min/1.73 m² and creatinine levels of 0.48 mg/dL. Managing cystinuria during the pandemic underscored the critical role of continuous access to medications like tiopronin in preventing renal deterioration. Developing strategies to ensure an uninterrupted drug supply during global health emergencies is crucial for managing chronic conditions such as cystinuria.

Ho: YAG laser lithotripsy is widely used for urinary stone treatment, but concerns persist regarding its thermal effects on renal tissues. This study aimed to monitor intrarenal temperature changes during kidney stone treatment using retrograde intrarenal surgery with Ho: YAG laser. Fifteen patients were enrolled. Various laser power settings (0.8 J/10 Hz, 1.2 J/12 Hz) and irrigation modes (10 cc/min, 15 cc/min, 20 cc/min, gravity irrigation, and manual pump irrigation) were used. A sterile thermal probe was attached to a flexible ureterorenoscope and delivered into the calyceal system via the ureteral access sheath. Temperature changes were recorded with a T-type thermal probe with ± 0.1 °C accuracy. Laser power significantly influenced mean temperature, with a 4.981 °C difference between 14 W and 8 W laser power (p < 0.001). The mean temperature was 2.075 °C higher with gravity irrigation and 2.828 °C lower with manual pump irrigation (p = 0.038 and p = 0.005, respectively). Body mass index, laser power, irrigation model, and operator duty cycle explained 49.5% of mean temperature variability (Adj. R² = 0.495). Laser power and operator duty cycle positively impacted mean temperature, while body mass index and specific irrigation models affected it negatively. Laser power and irrigation rate are critical for intrarenal temperature during Ho: YAG laser lithotripsy. Optimal settings and irrigation strategies are vital for minimizing thermal injury risk. This study underscores the need for ongoing research to understand and mitigate thermal effects during laser lithotripsy.

Introduction: This study aimed to identify a precise learning curve for pure retroperitoneoscopic donor nephrectomy (RDN). Methods: Data from 172 consecutive kidney donors who underwent pure RDN between January 2010 and July 2019 were prospectively collected and evaluated. CUSUM (cumulative sum) analysis was used for testing the operation time. Changepoints were determined by using the r program and Binseg method. The cohort was divided into three groups — group 1: competence, including the first 10 cases; group 2: 11–48 cases as proficiency; and group 3: the subsequent 124 cases as expert level. Continuous variables were evaluated using one-way ANOVA, and categorical data were evaluated using the Chi-squared test. Results: Right RDN was performed in 39 (22.7%) donors. The eighth patient was converted to open surgery due to vena cava injury and excluded from the CUSUM analysis. Depending on experience in pure RDN, a significant decrease was detected in operative time (p<0.001), warm ischemia time (p=0.006), and blood loss (p<0.001). Recipient complications and graft function were found to be statistically comparable. Conclusions: In our study, the attainment of expertise in pure RDN was observed after performing 50 cases. The transperitoneal technique, which is a feasible alternative, is far more widely used than pure RDN. We believe that understanding the learning curve associated with pure RDN could facilitate the adoption of this approach as a viable alternative to the transperitoneal approach.

Background: Adherent perinephric fat (APF) is one of the challenging factors of laparoscopic partial nephrectomy (LPN). The aim of this study was to investigate the effect of intraoperative laparoscopic ultrasound (ILUS) on determining renal tumor localization and dissection in patients with APF who underwent LPN. Methods: Prospectively collected data from 517 patients who underwent LPN from October 2010 to September 2020 in tertiary university hospital were evaluated retrospectively. The cohort was divided into two main groups according to the Mayo Adhesive Probability (MAP) score: Group 1 (MAP score ≤3) and Group 2 (MAP score ≥4). After implementing propensity score-matched analysis including the complexity of tumor, age, and body mass index, Group 1 consisted of 202 patients with ≤3 MAP score and Group 2 included 46 patients. Then, both groups were allocated into two subgroups according to whether ILUS was used. Demographics, perioperative features such as perirenal fatty tissue dissection, tumor excision, operation time, and perioperative outcomes accepted as trifecta, considering warm ischemia time, negative surgical margin, and complications were compared. Results: In Group 1, ILUS use did not seem to affect perioperative outcomes in both subgroups. However, ILUS has a positive effect on perirenal fatty tissue dissection (10 versus 19 minutes, P = .011), tumor excision (4 versus 7 minutes, P = .005), and operation time (78 versus 90 minutes, P = .046) in Group 2. Trifecta outcomes were also better in higher MAP scores and ultrasound-used subgroups (P = .019). Conclusions: ILUS should be considered a helpful and effective instrument in overcoming APF in LPN. It might also have a positive effect on trifecta outcomes.