Background and Objectives: This paper evaluates the efficacy and safety of ureteral access sheath (UAS) utilization in retrograde intrarenal surgery (RIRS). Materials and Methods: We searched PubMed, Embase, and the Cochrane Library up to 30 August 2023. The inclusion criteria comprised English-language original studies on RIRS with or without UAS in humans. The primary outcome was SFR, while the secondary outcomes included intraoperative and postoperative complications, the lengths of the operation and the hospitalization period, and the duration of the fluoroscopy. Subgroup analyses and a sensitivity analysis were performed. Publication bias was assessed using funnel plots and Egger\'s regression tests. Dichotomous variables were analyzed using odds ratios (ORs) with 95% confidence intervals (CIs), while mean differences (MDs) were employed for continuous variables. Results: We included 22 studies in our analysis. These spanned 2001 to 2023, involving 12,993 patients and 13,293 procedures. No significant difference in SFR was observed between the UAS and non-UAS groups (OR = 0.90, 95% CI 0.63-1.30, p = 0.59). Intraoperative (OR = 1.13, 95% CI 0.75-1.69, p = 0.5) and postoperative complications (OR = 1.29, 95% CI 0.89-1.87, p = 0.18) did not significantly differ between the groups. UAS usage increased operation times (MD = 8.30, 95% CI 2.51-14.10, p = 0.005) and fluoroscopy times (MD = 5.73, 95% CI 4.55-6.90, p < 0.001). No publication bias was detected for any outcome. Conclusions: In RIRS, UAS usage did not significantly affect SFR, complications, or hospitalization time. However, it increased operation time and fluoroscopy time. Routine UAS usage is not supported, and decisions should be patient-specific. Further studies with larger sample sizes and standardized assessments are needed to refine UAS utilization in RIRS.

Background: Percutaneous nephrolithotomy (PCNL) is the preferred treatment for the removal of large kidney stones, sized >20 mm. However, there is still an ongoing debate concerning the best anesthesia for PCNL. This study aimed to compare the efficacy and safety between general and spinal anesthesia for PCNL. Methods: A systematic review and meta-analysis study. A systematic, electronic literature search was performed in several databases, including PubMed, Scopus, and Google Scholar until July 1 st, 2022. The quality of the articles was examined using Crombie\'s Items (for non-randomized controlled trials (RCTs)) and Jadad Scale (for RCTs). The outcomes assessed were operation time, fluoroscopy time, length of stay, stone-free rate, overall complication rate, specific postoperative complications, cost, pain score, and postoperative analgesic requirement. The article selection was reported based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We assessed four RCTs and eight retrospective studies. Meta-analysis of selected studies was performed using the Review Manager 5.3. Results: General anesthesia resulted in fewer Clavien-Dindo grade II (OR: 0.68; 95% CI: 0.49 - 0.94; p=0.02), major complications (OR: 0.65; 95% CI: 0.45 - 0.94; p=0.02, and lower transfusion rates (OR: 0.70; 95% CI: 0.53 - 0.94; p=0.02). Whereas spinal anesthesia resulted in faster operation time (Mean Difference: -12.98; 95% CI: -20.56 - -5.41; p<0.001, fluoroscopy time (MD: -26.15; 95% CI: -42.79 - -9.50; p=0.002), reduced length of stay (MD: -0.47; 95% CI: -0.75 - 0.20; p<0.001), and lower postoperative analgesic requirement and cost. No significant difference in stone-free rate (OR: 1.08; 95% CI: 0.92 - 1.26; p=0.37). PCNL performed using either general anesthesia or spinal anesthesia is equally safe and effective. Conclusions: Each method of anesthesia has its own advantages and disadvantages. The final choice between general and spinal anesthesia should be based on the patient\'s condition and surgical team preference.

BACKGROUND: Thulium fiber laser (TFL) emerged as a competitor of holmium:yttrium aluminum garnet (Ho:YAG) laser for the treatment of urinary stones.
OBJECTIVE: To compare the efficacy between Ho:YAG and TFL for laser lithotripsy of renal and ureteral stones.
METHODS: A literature search was conducted using PubMed/Medline, Embase, and Web of Science databases to identify reports published until May 2023. The Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines were followed to identify eligible studies. The primary outcome was to compare the stone-free rate (SFR) between Ho:YAG and TFL for laser lithotripsy.
RESULTS: Eleven studies met our inclusion criteria, and data from 1286 and 880 patients who underwent, respectively, Ho:YAG and TFL laser lithotripsy were reviewed. Most studies included ureteroscopy (URS) and retrograde intrarenal surgeries as procedures, two included percutaneous nephrolithotomy, and one included URS exclusively. Only two studies reported results in pediatric patients. TFL was associated with a higher SFR (odds ratio [OR] 1.84, 95% confidence interval [CI]: 1.06-3.20; p = 0.031) when no residual fragment is considered, but not when SFR refers to the presence of fragments <3 mm (OR 2.48, 95% CI: 0.98-6.29; p = 0.055) or when only Ho:YAG with MOSES is considered (p = 0.068). According to the stones\' location, TFL was associated with higher SFRs than Ho:YAG for renal (OR 3.14, 95% CI: 1.69-5.86; p < 0.001) but not for ureteral (p = 0.8) stones. TFL was associated with a lower intraoperative complication rate (OR 0.34, 95% CI: 0.19-0.63; p < 0.001). No difference was found in major (p = 0.4) or overall (p = 0.4) complication rate, operative time (p = 0.051), and laser time (p = 0.9).
CONCLUSIONS: TFL is a promising laser for the treatment of urinary stones with some advantages over Ho:YAG. Further high-quality studies are needed to confirm these findings and optimize the surgical settings.
RESULTS: The use of thulium fiber laser rather than holmium:yttrium aluminum garnet permits to reach a higher stone-free rate in stones located in the kidney rather than in the ureter.

OBJECTIVE: To identify the latest advances in suction devices and evaluate their effect in Retrograde intrarenal surgery (RIRS) and ureteroscopy for stones.
METHODS: A systematic literature search was performed on 4th January 2023 using Scopus, PubMed, and EMBASE. Only English papers were included; both pediatric and adult studies were accepted. Duplicate studies, case reports, letters to the editor, and meeting abstracts were excluded.
RESULTS: Twenty-one papers were selected. Several methods have been proposed for suction use in RIRS, such as through the ureteral access sheath or directly to the scope. Artificial intelligence can also regulate this system, monitoring pressure and perfusion flow values. All the proposed techniques showed satisfactory perioperative results for operative time, stone-free rate (SFR), and residual fragments. Moreover, the reduction of intrarenal pressure (induced by aspiration) was also associated with a lower infection rate. Even the studies that considered kidney stones with a diameter of 20 mm or higher reported higher SFR and reduced postoperative complications. However, the lack of well-defined settings for suction pressure and fluid flow prevents the standardization of the procedure.
CONCLUSIONS: Aspiration device in the surgical treatment of urinary stones favours a higher SFR, reducing infectious complications, as supported by the included studies. RIRS with a suction system provided to be a natural successor to the traditional technique, regulating intrarenal pressure and aspirating fine dust.

OBJECTIVE: The aim of this review is to summarize the existing suction systems in flexible ureteroscopy (fURS) and to evaluate their effectiveness and safety.
METHODS: A narrative review was performed using the Pubmed and Web of Science Core Collection (WoSCC) databases. Additionally, we conducted a search on the Twitter platform. Studies including suctions systems in fURS were included. Editorials, letters and studies reporting intervention with semirigid ureteroscopy, PCNL and mPCNL were excluded.
RESULTS: A total of 12 studies were included in this review. These studies comprised one in vitro study, one ex vivo study, one experimental study and eight cohort studies. The Pubmed and WoSCC searches identified three suction techniques (Irrigation/Suctioning system with control of pressure, suction ureteral access sheath (sUAS) and direct in scope suction (DISS)), and the Twitter search identified four of them. The overall results showed that suction is an effective and safe technique that improves stone-free rates, reduces operative time and limits complication rates after fURS.
CONCLUSIONS: The use of suctioning during common endourological procedures has been shown to improve safety and efficacy in several indications. However, randomized controlled trials are needed to confirm this.

Background: To assess the efficacy and safety of micro-percutaneous nephrolithotomy (Microperc) and mini-percutaneous nephrolithotomy (Miniperc) in the treatment of moderately sized renal stones. Methods: Literature search of PubMed, Web of Science, and Embase was performed prior to January 2021. We used odds ratios (OR) and weighted mean difference (WMD) for dichotomous variables and continuous variables, respectively. Results were pooled using Review Manager version 5.3 software. Results: A total of six studies involving 291 Microperc and 328 Miniperc cases was included. The overall stone-free rate (SFR) of Microperc was 87.29% (254/291), while the SFR of Miniperc was 86.59% (284/328). Microperc was associated with lower hemoglobin drop (WMD: -0.98; P = 0.03) and higher renal colic requiring D-J stent insertion (OR: 3.49; P = 0.01). No significant differences existed between Microperc and Miniperc with respect to SFR (OR: 1.10; P = 0.69), urinary tract infection (OR: 0.38; P = 0.18), operative time (WMD: -5.76; P = 0.62), and hospital stay time (WMD: -1.04; P = 0.07). Conclusions: Our meta-analysis demonstrated that Microperc could produce an SFR that was comparable with that of Miniperc. Microperc was associated with lower hemoglobin drop, while Miniperc was associated with lower renal colic rates. In addition, the operation time and hospital stay time for both these procedures were similar.

OBJECTIVE: The purpose of this study was to retrospectively assess the efficacy and safety of minimally invasive nephrolithotomy (MPCNL) versus retrograde intrarenal surgery (RIRS) in the management of upper urinary stones.
METHODS: A comprehensive literature review of articles that investigated the efficacy and safety of MPCNL and RIRS was conducted by systematically searching PubMed, EMBASE, and Cochrane Library in March 2019. Two reviewers searched the literature, independently extracted the data and evaluated the quality of the data according to the inclusion and exclusion criteria. A meta-analysis was performed by using Review Manager 5.3 software.
RESULTS: Eight randomized controlled trials (RCTs) involving 725 patients with upper urinary stones were analysed based on the inclusion criteria. While MPCNL has a better clinical efficacy than RIRS with respect to the stone-free rate (SFR) [RR = 1.11, 95% CI (1.05-1.17), p = 0.0005], MPCNL has a higher incidence of haematoma [RR = 3.09, 95% CI (1.44-6.66), p = 0.004] and longer hospitalization time [MD = 0.89 day, 95% CI (0.07-1.72), p = 0.04]. In addition, no significant difference in operative time [MD = 2.46 min, 95% CI (-17.99 to 22.92), p = 0.81] and postoperative pain score [MD = 0.74, 95% CI (-0.45 to 1.94), p = 0.22] were observed between the two methods. Overall, the evidence was insufficient to suggest a statistically significant difference in the adverse event profile for MPCNL compared with RIRS.
CONCLUSIONS: Our data suggest that MPCNL is an effective method for treating upper urinary stones, especially lower calyceal stones that are 1-2 cm in size. Compared to RIRS, MPCNL is associated with a longer hospital stay time and a higher incidence of haematoma. In addition, both methods have proven to be safe. Nevertheless, the findings should be further confirmed through well-designed prospective RCTs with a larger patient series.

To evaluate the efficiency and safety of preoperative double-J stent placement for patients undergoing ureteroscopic lithotripsy. Eligible studies were identified from electronic databases (PubMed, Embase, the Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews). All analyses were performed by the Review Manager 5.3 (The Cochrane Collaboration, Oxford, UK). Stone-free rate (SFR) was regarded as primary outcome. Second outcomes, including operation time, complication rates as well as major complication rates were also assessed. A total of 11,239 patients (2605 with and 8634 without preoperative stent) from nine retrospective studies were included. Our pooled analysis showed that SFR was significantly higher in patients with a preoperative stent than those without a stent (OR 1.60, 95% CI 1.19-2.15, p = 0.002). Operation time was not significantly different between stented and non-stented groups (OR - 0.89, 95% CI - 5.79-4.01, p = 0.72). No significant differences of complication rates were observed between stented and non-stented groups (OR 0.94, 95% CI 0.67-1.33, p = 0.73). Furthermore, major complication rates were not significantly different between two groups, either (OR 1.07, 95% CI 0.43-2.70, p = 0.88). Generally, preoperative double-J stent placement significantly improved SFR of patients undergoing ureteroscopic lithotripsy. Operation time, complication rates, as well as major complication rates, were similar between stented and non-stented groups. However, the effect of preoperative double-J stent placement for different locations and burden of stones is unclear, more high-quality studies should be anticipated.

Miniaturized percutaneous nephrolithotomy (MPCNL), including minipercutaneous nephrolithotomy (PCNL), ultramini-PCNL, and micro-PCNL, have been developed recently. The aim of this meta-analysis was to compare the safety and efficacy of different tract sizes of MPCNL with retrograde intrarenal surgery (RIRS) in the management of kidney stones.
We searched PubMed, Embase, and Web of Science to identify case-control trials and randomized controlled trials, which evaluated MPCNL vs RIRS before February 2017. Two reviewers independently evaluated the methodologic quality of the included studies, and the disagreements were solved by discussion. Meta-analysis was performed with Review Manager version 5.3 software.
Fourteen publications involving 1279 patients were included. Mini-PCNL provided a significantly higher stone-free rate (SFR; odds ratio [OR] OR 1.66; p = 0.005), especially for lower pole renal stones (OR 2.65; p = 0.003), but brought longer hospital stay (weighted mean difference [WMD] 1.23; p = 0.0001) and larger hemoglobin drop (WMD 0.77; p < 0.00001). There were no statistically significant differences between mini-PCNL and RIRS in the complications (OR 0.77; p = 0.23) and operative time (WMD: -6.52; p = 0.42). For ultramini-PCNL and micro-PCNL, the safety and efficacy were similar to RIRS.
Mini-PCNL offers a significantly higher SFR than RIRS, for lower pole renal stones, the advantage of mini-PCNL is more obvious. However, RIRS is associated with shorter hospital stay and less hemoglobin drop. For ultramini-PCNL and micro-PCNL, tract size is smaller than mini-PCNL, and the SFR is similar to RIRS. In terms of the evidence at present, we recommend mini-PCNL for patients focusing more on the high SFR.

BACKGROUND: Percutaneous nephrolithotomy (PCNL) has been widely used to treat renal stones. The application of PCNL in obese patients results in the emergence of a number of challenges. This study compared the effect of obesity on the outcomes of PCNL in kidney stone treatment.
METHODS: Eligible studies were searched in PubMed, Web of Science, and Cochrane Library databases. Data were analyzed using RevMan statistical software, weighted mean differences, ORs, and 95% CIs were calculated.
RESULTS: Seven studies involving 2,720 normal-weight, 1,686 obese, and 286 super-obese individuals were included in this meta-analysis. A pooled analysis of safety revealed that no obvious differences in terms of complication rates after treatment existed between obese and normal-weight individuals (OR 0.97, 95% CI 0.80-1.16, p = 0.73), and between super-obese and normal-weight individuals (OR 0.88, 95% CI 0.61-1.27, p = 0.49). A pooled analysis of effectiveness revealed that no obvious difference in terms of stone-free rate after treatment existed between obese and normal-weight individuals (OR 0.98, 95% CI 0.84-1.15, p = 0.79), and between super-obese and normal-weight individuals (OR 1.20, 95% CI 0.88-1.63, p = 0.25). Moreover, no obvious differences in terms of length of hospital stay after treatment existed between super-obese and normal-weight individuals (95% CI -0.15 to 0.37, p = 0.39). Additionally, no obvious differences in terms of operation time existed between obese and normal-weight individuals (95% CI -3.36 to 1.17, p = 0.34). However, the operation time was longer among super-obese individuals than among normal-weight individuals (95% CI -22.64 to -1.40, p = 0.03), and the length of hospital stay was shorter among obese patients than among normal-weight patients (95% CI 0.04-0.34, p = 0.01). No publication bias was observed in this work.
CONCLUSIONS: The PCNL performed in normal-weight, obese, and super-obese individuals for kidney stone treatment showed similar outcomes, except that operation time was longer among super-obese individuals and the hospital stay was shorter in obese individuals than in other groups. Thus, PCNL is a safe and efficacious treatment for renal stones in patients of all sizes.