A case of allograft ureteral stone successfully treated with antegrade ureteroscopic lithotripsy: use of a 3D-printed model to determine the ideal approach Abstract We present the case of a 46-year-old man who underwent successful antegrade ureteroscopy for lithiasis in his allograft ureter. At a scheduled follow-up 15 years after transplantation, computed tomography (CT) detected a 12-mm renal stone in the renal pelvis of the transplanted kidney. During his follow-up, gross hematuria was seen; the stone moved to the ureter, causing hydronephrosis. Ultrasound and non-contrast CT revealed hydronephrosis and a 15-mm stone in the transplanted ureter. Considering the stone size, location, and the difficulty of the access to the anastomosed ureteral orifice, percutaneous ureteroscopic approach was planned. Due to the anatomical difficulty regarding his allograft kidney, we planned to prepare a 3D image and model for selecting the best percutaneous approach. The procedure was performed and a stone-free status was acquired without complication. Under precise simulation, we performed successful antegrade ureteroscopy for lithiasis in the allograft ureter supported by 3D imaging. Use of a 3D printed model may aid in a safe and effective procedure for lithiasis in the allograft kidney and ureter.

Recurrent kidney stones in a family with a mitochondrial disorder due to the m.3243A>G mutation

New techniques on uropaleopathology

Adolescents with urinary stones have elevated urine levels of inflammatory mediators Abstract Urinary stones are increasing in children, primarily during adolescence. Although urinary stones are often viewed in the context of intermittent stone events, increasing evidence indicates that stones are a metabolic process associated with chronic kidney disease and cardiovascular disease. These aforementioned stone-associated conditions may have pediatric origins. To compare urine inflammatory markers in otherwise healthy stone forming children versus matched controls. Urine samples were collected from 12 adolescents with urinary stones along with 15 controls. The levels of 30 urine cytokines were measured using a Mesoscale 30-Plex Human Cytokine panel and normalized to urine creatinine levels. Macrophage inflammatory protein 1β and interleukin 13 levels were significantly elevated in the urine of the stone forming adolescents compared to controls. Interleukin 17A was elevated in the urine of controls. This study indicates that urine levels of cytokines involved in chronic inflammation and fibrosis are elevated in urinary stone formers as early as adolescence. Because stone formers are at risk for chronic kidney disease, macrophage inflammatory protein 1β and interleukin 13 represent investigative targets.

Vision for the future on urolithiasis: research, management, education and training—some personal views Abstract The field of urolithiasis has undergone many rapid changes in the last 3 decades. In this article, three eminent experts in various fields of urolithiasis research describe their respective visions for the future in stone research, stone treatment and surgical training. Many stone researchers have seen and regretted that there has not been a real breakthrough for decades now. Exceptions are the application of citrate prophylaxis and the abandonment of calcium-avoiding diet in stone formers. Certain areas of stone research have been exhausted and the body of literature available should suffice as background knowledge in those. Yet, to find meaningful mechanisms of clinically applicable stone prevention, the limited funds which are currently available should be used to research priority areas, of which crystal–cell interaction is envisioned by one of the present authors as being a crucial direction in future stone research. In the opinion of the second author, surgical stone treatment is very much technology-driven. This applies to the evolution of existing technologies and instruments. In addition, robotics, IT and communication software, and artificial intelligence are promising and are steadily making a meaningful impact in medicine in general, and endourology in particular. Finally, the third author believes that despite the exciting advances in technology, the role of the surgeon can never be replaced. The idea of a fully automated, artificially thinking and robotically performing system treating patients medically and surgically will not appeal to urologists or patients but may at least be a partial reality. His vision therefore is that surgical training will have to take on a new dimension, away from the patient and towards virtual reality, until the skill set is acceptably developed.

Factors affecting infectious complications following flexible ureterorenoscopy Abstract In the present study, we aimed to clarify predictive factors that may cause postoperative infectious complications after flexible ureterorenoscopy (f-URS). In a 4-year prospective study, charts of patients who underwent f-URS between January 2014 and January 2018 for renal stone(s) in a tertiary academic center were reviewed. A standardized f-URS procedure was performed for all patients. Post-operative infectious complications including fever, sepsis and septic shock were categorized into same group. Patients with and without infectious complications were compared in the terms of preoperative, operative and post operative characteristics. In total, 463 patients who did not face infectious complications and 31 patients who faced infectious complications were enrolled into the study. The mean age was significantly lower in patients who did face infectious complications (34.8 vs 44.7 years old, p < 0.001). On the other hand, presence of renal abnormality was significantly more common in patients with infectious complications (12.3% vs 35.5%, p < 0.001). The mean operation time was 65.3 min in patients with infectious complications and significantly longer when compared with patients who did not face infectious complication (47.8 min, p < 0.001). Stone-free rate was significantly higher in patients without infectious complications (85.3% vs 77.5, p = 0.009). Multivariate regression analysis revealed that longer operation time ≥ 60 min, presence of renal abnormality and age ≤ 40 years were predictive factors for infectious complications following f-URS. The present study has demonstrated that operation time ≥ 60 min, presence of renal abnormality and patients with ≤ 40 years were significantly associated with infectious complications following f-URS.

A preliminary study: the role of preoperative procalcitonin in predicting postoperative fever after mini-percutaneous nephrolithotomy in patients with a negative baseline urine culture Abstract To evaluate the role of preoperative procalcitonin (PCT) levels in predicting postoperative fever after mini-percutaneous nephrolithotomy (mini-PCNL) in patients with a negative baseline urine culture. Between January 2014 and October 2017, 329 patients with a negative baseline urine culture and who underwent mini-PCNL were enrolled in this study. Patients were stratified into the control or febrile group based on a body temperature either less than or greater than 38 °C, respectively. Demographic and perioperative data were compared between the groups, and variables found to be statistically significant were included in a binary logistic regression analysis. A total of 68 (20.6%) patients experienced postoperative fever. The univariate analysis revealed a statistically significant difference between groups in preoperative fever (p = 0.032), stone burden (p < 0.001), C-reactive protein (p = 0.011), PCT (p < 0.001) and interleukin-6 (p = 0.035) levels. Binary logistic regression analysis indicated that stone burden > 353 mm3 (p = 0.003) and PCT > 0.05 ng/mL (p < 0.001) are independent risk factors for postoperative fever in mini-PCNL-treated patients with a negative baseline urine culture. We concluded that patients with stone burden > 353 mm3 or PCT > 0.05 ng/mL were more likely to develop postoperative fever after mini-PCNL, though with a negative baseline urine culture.

Incorporation of osteopontin peptide into kidney stone-related calcium oxalate monohydrate crystals: a quantitative study Abstract Polyelectrolyte–crystal interactions regulate many aspects of biomineralization, including the shape, phase, and aggregation of crystals. Here, we quantitatively investigate the role of phosphorylation in interactions with calcium oxalate monohydrate crystals (COM), using synthetic peptides corresponding to the sequence 220–235 in osteopontin, a major inhibitor of kidney stone-related COM formation. COM formation is induced in the absence or presence of fluorescent-labeled peptides containing either no (P0), one (P1) or three (P3) phosphates and their adsorption to and incorporation into crystals determined using quantitative fluorimetry (also to determine maximum adsorption/incorporation), confocal/scanning electron microscopy and X-ray/Raman spectroscopy. Results demonstrate that higher phosphorylated peptides show stronger irreversible adsorption to COM crystals (P3: K0 ~ 66.4 × 106 M−1; P1: K0 ~ 29.4 × 106 M−1) and higher rates of peptide incorporation into crystals (maximum: P3: ~ 58.8 ng and P1: ~ 8.9 ng per µg of COM) than peptides containing less phosphate groups. However, crystals grown at that level of incorporable P3 show crystal-cleavage. Therefore, extrapolation of maximum incorporable P3 was carried out for crystals that are still intact, resulting in ~ 49.1 ng P3 µg−1 COM (or ~ 4.70 wt%). Both processes, adsorption and incorporation, proceed via the crystal faces {100} > {121} > {010} (from strongest to weakest), with X-ray and Raman spectroscopy indicating no significant effect on the crystal structure. This suggests a process in which the peptide is surrounded by growing crystal matrix and then incorporated. In general, knowing the quantity of impurities in crystalline/ceramic matrices (e.g., kidney stones) provides more control over stress/strain or solubilities, and helps to categorize such composites.

Protective effect of pentoxifylline on oxidative renal cell injury associated with renal crystal formation in a hyperoxaluric rat model Abstract The aim of the study is to investigate the effects of pentoxifylline (PTX) on the renal tubular cell injury and stone formation in a hyperoxaluric rat model induced by ethylene glycol and its possible underlying mechanisms. The study was performed with 30 male Wistar rats and randomized into three groups of teen. The sham-control (group 1) received only drinking water orally. The EG/untreated (group 2) received drinking water containing 0.75% EG for 4 weeks orally. The EG/PTX treated (group 3) received drinking water containing 0.75% EG for 4 weeks orally and PTX. Urine and blood were collected to determine some parameters. The kidneys were also removed for histological examination. Serum and urinary parameters were significantly improved in the EG/PTX treated. In the EG/PTX-treated group, the MDA, TOS and MPO activity reduced and the TAS, SOD, CAT and GSH-Px activities were increased markedly compared with the group 2. In urine of the group 2 rats, a large number of CaOx crystals were displayed and most tubules that contained crystals were dilated and showed degeneration, necrosis, and desquamation of the lining epithelium. Only few CaOx crystals were r in EG/PTX-treated animal’s urine. Mild tissue damage was observed in PTX-treated rats. iNOS expression was significantly elevated in the group 2. In contrast, in the EG/PTX-treated group, eNOS expression in renal tubular epithelial cells was increased. Current study indicates that PTX may partially reduce renal tubular injury resulting from hyperoxaluria-induced oxidative and nitrosative stress.

Baseline chronic kidney disease does not predict long-term renal functional decline after percutaneous nephrolithotomy Abstract To compare renal functional outcomes in patients with and without chronic kidney disease (CKD) to identify predictors of change in renal function after percutaneous nephrolithotomy (PCNL). We reviewed patients who underwent PCNL by a single surgeon over 3.5 years. Patients’ pre- and post-operative Glomerular Filtration Rate (GFR) was calculated. Baseline GFR < 60 ml/min/1.73 m2 (stage ≥ 3 CKD) defined our CKD cohort. Patients’ baseline renal function, comorbidities, stone parameters, and intra-operative variables were analyzed to determine the relationship with post-operative renal function after PCNL by multivariate analysis. 202 patients were analyzed. Mean follow-up time was 16 months. At baseline, 163 (80.7%) patients were free of CKD and 39 (19.3%) had CKD. Patients without CKD had an overall decrease in GFR from 105.6 to 103.3 ml/min/1.73 m2 (p = 0.494). 14/163 (8.6%) non-CKD patients experienced a significant decline in renal function after PCNL; 7/163 (4.3%) developed de novo CKD and 7 had a ≥ 30% decline in GFR. Patients with CKD had an overall increase in mean GFR post-operatively, from 47.3 to 54.0 ml/min/m2 (p = 0.067). Two in this cohort (5.1%) experienced a > 30% decline in renal function post-operatively. Age, gender, African American race, presence of comorbidities and pre-operative CKD were not significant predictors of renal function post-operatively on multivariate analysis. PCNL in this cohort appears GFR neutral in the setting of baseline CKD. CKD was not predictive of renal functional decline after PCNL. Given that stone disease carries a high recurrence rate and that CKD is associated with stone formers, further investigation into predictors of renal function change after PCNL is warranted.