Keywords: Ureteroscopy; Nephrolithotomy; Percutaneous; Kidney Calculi

Staghorn calculi remain a treatment challenge for urologists. The aim of the study was to compare the treatment outcomes of suctioning minimally invasive percutaneous nephrolithotomy (MPCNL) and traditional MPCNL for renal staghorn stones. Between April 2018 and June 2019, we included patients suffering from renal staghorn stones who were treated with modified MPCNL with a suctioning system. The outcomes of these patients were compared with those of a cohort of patients undergoing traditional MPCNL (between January 2017 and March 2018) using a 1:1 scenario matched-pair analysis. Cases were matched sequentially according to stone burden, stone branches, and stone hardness as well as age and sex. A total of 512 patients were included in this study (256 patients in each group). The baseline characteristics were equally distributed between the two groups. The suctioning MPCNL group achieved a significantly higher stone-free rate (SFR) (78.5% vs 69.1%; P = 0.016) after a single procedure and had a significantly shorter operative time (106.2 ± 18.4 vs. 132.1 ± 22.2 min; P < 0.001) than the traditional MPCNL group. The traditional MPCNL group experienced a significantly higher rate of overall complications than the suctioning MPCNL group (27.3% vs. 16.8%; P = 0.004). Regarding individual complications, a significantly higher rate of fever (13.7% vs. 7.4%; P = 0.021) and urosepsis requiring only additional antibiotics (8.2% vs. 3.5%; P = 0.024) was observed in the traditional MPCNL group than in the suctioning MPCNL group; there was a trend that the suctioning MPCNL group conferred a decreased risk of urosepsis shock (1.2% vs. 2.3%), but this trend failed to achieve statistical significance (P = 0.313). There was no significant difference between the two groups regarding the incidence of severe hemorrhage, the mean number of tracts used during a single procedure and the postoperative hospital stay. The use of suctioning MPCNL for staghorn calculi had advantages over the use of traditional MPCNL in terms of a higher SFR after a single procedure and fewer postoperative infectious complications. Further well-designed studies are needed to confirm the results.

Background: Randall’s plaques (RP) are identified as anchored sites for kidney calcium oxalate stones, but the mechanism remains unclear. Given the importance of osteogenic-like cells in RP formation and OCT4 in reprogramming differentiated cells to osteoblasts, the current study explored the potential role of OCT4 in RP formation. Methods: OCT4 and biomineralization were evaluated in RP, and immunofluorescence co-staining was performed to identify these cells with alteration of OCT4 and osteogenic markers. Based on the analysis of tissue, we further investigated the mechanism of OCT4 in regulating osteogenic-like differentiation of primary human renal interstitial fibroblasts (hRIFs) in vitro and vivo. Results: We identified the upregulated OCT4 in RP, with a positive correlation to osteogenic markers. Interestingly, fibroblast marker Vimentin was partially co-localized with upregulated OCT4 and osteogenic markers in RP. Further investigations revealed that OCT4 significantly enhanced the osteogenic-like phenotype of hRIFs in vitro and in vivo. Mechanically, OCT4 directly bound to BMP2 promoter and facilitated its CpG island demethylation to transcriptionally promote BMP2 expression. Furthermore, combination of RIP and RNA profiling uncovered that lncRNA OLMALINC physically interacted with OCT4 to promote its stabilization via disrupting the ubiquitination. Additionally, OLMALINC was upregulated in fibroblasts in RP visualized by FISH, and a positive correlation was revealed between OLMALINC and OCT4 in RP. Conclusions: The upregulation of OCT4 in hRIFs was a pathological feature of RP formation, and OLMALINC/OCT4/BMP2 axis facilitated hRIFs to acquire osteogenic-like phenotype under osteogenic conditions, through which the pathway might participate in RP formation. Our findings opened up a new avenue to better understand RP formation in which osteogenic-like process was partially triggered by lncRNAs and pluripotency maintenance related genes.

Objective: To assess the long-term outcome of simultaneous treatment of a single renal cyst and ipsilateral stones with transurethral flexible ureteroscopy (FURS) lithotripsy and internal cyst drainage. Methods: Patients who underwent simultaneous treatment with FURS lithotripsy and internal cyst drainage in our institution between July 2014 and September 2017 were enrolled. The cyst wall was identified endoscopically and a 1–3-cm window was created in the wall using a holmium laser. The proximal end of a double-J stent was placed in the cystic cavity to facilitate internal drainage. Results: Thirteen patients underwent simultaneous treatment. No intraoperative complications with Clavien grading score >2 were noted in any patients. Mean stone burden and cyst diameter were 1.6 (range: 0.9–2.5) cm and 5.8 (range: 3.0–7.1) cm, respectively. Stone-free rates after single and complementary procedures were 84.6% and 92.3%, respectively. During the mean 33.1-month follow-up period (range: 17–54 months), seven patients (53.8%) achieved full resolution of renal cysts, five patients (38.5%) maintained >50% size reduction, and one patient (7.6%) experienced recurrence at 18 months postoperatively. Conclusions: FURS with a holmium laser may constitute a safe and effective alternative procedure for simultaneous treatment of a single renal cyst and ipsilateral stones.