Flexible ureterorenoscopy versus miniaturized PNL for solitary renal calculi of 10-30 mm size

Comparison of the effectiveness of two adjustable negative pressure ureteral access sheaths combined with flex ureteroscopy for ≤ 2 cm renal stones

To compare the safety and effectiveness of the combination of intelligent intrarenal pressure control platforms (IPCP) and flexible ureteral access sheath (FUAS) combined with retrograde intrarenal surgery (RIRS) for the treatment of renal stones less than 2 cm. We retrospectively collected 383 patients with renal stones who underwent RIRS in our department from June 2022 to October 2023. Inclusion criteria: stone length or the sum of multiple stone lengths ≤ 2 cm. Finally, 99 cases were included and divided into an IPCP group (n = 40) and FUAS group (n = 59) based on surgical methods. The main endpoint was the stone-free rate (SFR) at third months after surgery, with no residual stones or stone fragments less than 2 mm defined as stone clearance. The secondary endpoints were surgical time and perioperative complications, including fever, sepsis, septic shock, and perirenal hematoma. There was no statistically significant difference in general information between the two groups, including age, gender, body mass index, comorbidities, stone side, stone location, stone length, urine bacterial culture, and hydronephrosis. The operation time for IPCP group and FUAS group was 56.83 ± 21.33 vs 55.47 ± 19.69 min (p = 0.747). The SFR of IPCP group and FUAS group on the first postoperative day was 75.00% vs 91.50% (p = 0.024). The SFR was 90.00% vs 94.90% in the third month (p = 0.349).In IPCP group, there were 11 cases with stones located in the lower renal calyces and 17 cases in FUAS group. The SFR of the two groups on the first day and third months after surgery were 45.50% vs 88.20% (p = 0.014) and 63.60% vs 94.10% (p = 0.040), respectively, with statistical differences. For kidney stones ≤ 2 cm, there was no difference in SFR and the incidence of infection-related complications between IPCP and FUAS combined with RIRS, both of which were superior to T-RIRS. For lower renal caliceal stones, FUAS has a higher SFR compared to IPCP.

The Saudi urological association guidelines on urolithiasis

Aims

The Saudi Urolithiasis Guidelines are a set of recommendations for diagnosing, evaluating, and treating urolithiasis in the Saudi population. These guidelines are based on the latest evidence and expert consensus to improve patient outcomes and optimize care delivery. They cover the various aspects of urolithiasis, including risk factors, diagnosis, medical and surgical treatments, and prevention strategies. By following these guidelines, health-care professionals can improve care quality for individuals with urolithiasis in Saudi Arabia.

Panel

The Saudi Urolithiasis Guidelines Panel consists of urologists specialized in endourology with expertise in urolithiasis and consultation with a guideline methodologist. All panelists involved in this document have submitted statements disclosing any potential conflicts of interest.

Methods

The Saudi Guidelines on Urolithiasis were developed by relying primarily on established international guidelines to adopt or adapt the most appropriate guidance for the Saudi context. When necessary, the panel modified the phrasing of recommendations from different sources to ensure consistency within the document. To address areas less well covered in existing guidelines, the panel conducted a directed literature search for high quality evidence published in English, including meta analyses, randomized controlled trials, and prospective nonrandomized comparative studies. The panel also searched for locally relevant studies containing information unique to the Saudi Arabian population. The recommendations are formulated with a direction and strength of recommendation based on GRADE terminology and interpretation while relying on existing summaries of evidence from the existing guidelines.

Minimally invasive nephrolithotomy versus retrograde intrarenal surgery in surgical management of Lower calyceal stones: a systematic review with meta-analysis

OBJECTIVE

The efficacy and safety of minimally invasive nephrolithotomy (MPCNL) versus retrograde intrarenal surgery (RIRS) was assessed for lower calyceal (LC) stones.

METHODS

Our team conducted a systematic literature search up to December, 2022, using PUBMED, EMBASE and the Cochrane Library. The study was registered in PROSPERO, CRD 42021247197. Randomized controlled trials evaluating the efficacy and safety of MPCNL versus RIRS for LC stones were collected. Heterogeneity among the studies was assessed using the χ 2 test based on the Q and I2 tests. Pooled effect sizes were calculated using a fixed model if I2 is less than 50%; otherwise, a random-effects model was chosen. The primary outcomes were the 3-month stone-free rate (3SFR) and total complications, while the secondary outcomes were the operating time, hospital stay, haemoglobin reduction, bleeding, postoperative fever and complications with the Clavien-Dindo system. A subgroup analysis of 10-20 mm LC stones was also designed.

RESULTS

A total of 7 peer-reviewed trials comprising 711 patients were identified. No statistical differences were observed in the heterogeneity results of the 3SFR or total complications ( P >0.1, I2 < 50%). Compared with RIRS, MPCNL had an unfavourable safety profile, resulting in total complications [odds ratio (OR): 1.87 (95% CI: 1.05, 3.33); P =0.03], haemoglobin reduction [OR: 0.81 (95% CI: 0.15, 1.47); P =0.02] and complications with Grade I [OR: 5.52 (95% CI: 1.34, 22.83); P =0.02] but an improved efficacy and 3SFR [OR: 2.43 (95% CI: 1.48, 3.97); P =0.0004]. As for the 10-20 mm LC stones, compared with RIRS, MPCNL also had an unfavourable safety profile, resulting in total complications [OR: 2.47 (95% CI: 1.20, 5.07); P =0.01], complications with Grade I [OR: 4.97 (95% CI: 0.99, 25.01); P =0.05] and an increased hospital stay [OR: 2.46 (95% CI: 2.26, 2.66); P =0.00001] but an improved efficacy and 3SFR {OR: 3.10 (95% CI: 1.61, 5.99); P =0.0008]. The efficacy effect of MPCNL and safety effect of RIRS were nearly equal for both stones sized less than 20 mm (number needed to treat = 17, number needed to harm = 20) and stones sized 10-20 mm (number needed to treat = 20, number needed to harm = 13). No statistical difference was found between the MPCNL and RIRS groups for the rest of outcomes.

CONCLUSION

Both MPCNL and RIRS are safe and effective management methods. Moreover, compared with RIRS, MPCNL had an unfavourable safety profile but improved efficacy for LC stones of ≤20 mm or 10-20 mm, and the differences were statistically significant. The relative profit of efficacy of MPCNL was similar to the relative profit of safety of RIRS.

External validation of the current scoring systems and derivation of a novel scoring system to predict stone free rates after retrograde intrarenal surgery in patients with cumulative stone diameter of 2-4 cm

OBJECTIVE

Our primary aim is to perform the external validation of the current scoring systems in predicting stone-free status (SFS) after retrograde intrarenal surgery (RIRS) for renal stones 2-4 cm and develop a novel scoring system by re-examining possible predictive factors related to SFS.

METHODS

Patients who underwent RIRS due to renal stones with a cumulative stone diameter of 2-4 cm between January 2017 and March 2021 were retrospectively screened. Residual stones ≤2 mm were defined as clinically insignificant, and these cases were considered to have SFS. Possible predictive factors related to SFS were examined using the multivariate logistic regression analysis. A nomogram and a scoring system were developed using independent predictive variables. The prediction ability of the previous and the new scoring system were evaluated with the ROC analysis.

RESULTS

The existing scoring systems were found to be insufficient in predicting SFS (AUC < 0.660 for all). The independent predictors of SFS were identified as stone surface area (OR: 0.991, p < 0.001), stone density (OR: 0.998, p < 0.001), number of stones (OR: 0.365, p = 0.033), and stone localization (p = 0.037). Using these predictive markers, a new scoring system with a score ranging between 4 and 15 was developed. The AUC value for this scoring system was 0.802 (0.734-0.870).

CONCLUSION

The RUSS, S-ReSC and R.I.R.S. scoring systems and Ito's nomogram failed to predict SFS in stones >2 cm. The SFS predictive ability of our new scoring system was higher in >2 cm stones compared to the other scoring systems.

Mini-Perc for Renal Stones—A Single Center Experience and Literature Review

Aim: The aim of this study was to analyze the outcomes of miniaturized nephrolithotomy (mini-perc) in the management of renal stones with a diameter smaller than 20 mm. Materials and Methods: We retrospectively reviewed the records of 102 patients who underwent mini-perc between March 2015 and March 2020 in our department. The primary objective was the stone-free rate, but we also analyzed the retreatment rate, complications, hospital stay, operative time and reduction in hemoglobin level. All these patients had this technique as their first-line treatment, in a prone position, using a 16 Fr sheath size. Data were compared to a series of patients from the literature, treated with conventional PCNL. Results: The patients had calculus limited to either a single calyx or just extending to the renal pelvis, and stone size was less than 20 mm in its maximal dimension. The intrarenal stone location was in the upper calyx in 7 cases, middle calyx in 20 cases and lower calyx in 46 cases, and there were 29 patients with renal pelvis stone. The male to female ratio was 1.5:1, and the median age was 48.4 years. The average stone size was 17.4 mm in diameter (ranging between 9 and 20 mm) and all cases underwent Ho-YaG laser lithotripsy, ballistic energy and combined ultrasonic and ballistic lithotripsy. At the end of the procedure, an antegrade double J stent was placed under fluoroscopy for a maximum of 2 weeks in 42 cases, while 9 cases needed a nephrostomy tube 12–14 F. A total of 51 cases were totally tubeless. Our median operative time was 61 min (ranging from 35 to 75 min). The median hospitalization stay was 3.8 days. The stone free rate was 90.1% after one procedure, only nine (8.8%) cases needed a “second look” flexible ureteroscopy, and the final stone-free rate was 98% (absence of detectable calculi on ultrasound, KUB or non-contrast CT scan). The overall complication rate was 6.86% (Clavien classification I—57.14%; II—28.5%; III—14.2%), while no Clavien IV or V complications were reported. No patient required a blood transfusion, and mean hemoglobin loss was 0.81 mg/dL. Overall, our results are better than similar data for conventional PCNL in the literature. Conclusions: The “mini-perc” technique is an effective procedure for the treatment of the renal lithiasis that is less or equal to 2 cm. The results demonstrated that this minimally invasive technique is associated with a higher stone-free rate and minimal complications.

Efficacy and safety of percutaneous nephrolithotripsy in elderly patients: a retrospective study

Background

Percutaneous nephrolithotripsy (PCNL) is difficult to perform for elderly patients; thus, this study aimed to assess its efficacy and safety in elderly patients aged > 70 years, note any associations between outcomes and patient characteristics, and summarize relevant themes and observations.

Methods

Data from patients older than 70 years who had undergone PCNL for upper urinary tract calculi between January 2016 and January 2021 was retrospectively analyzed. Risk factors for postoperative complications and residual stones were analyzed using multivariate logistic regression.

Results

A total of 116 elderly patients underwent 122 PCNL operations, of which six underwent secondary PCNL operations, and all of which were successfully completed. The average age was 74.6 ± 4.3 years; the average stone size and operation time were 3.5 ± 1.8 (1.2–11 cm), and 71.8 ± 34.1 min, respectively. Of the participants, 16 or 13.8% had postoperative complications and 29 (25%) had residual stones after operation. The stone free rate was 75%. Multivariate analysis revealed that an American Score of Anesthesiology III was an independent risk factor for postoperative complications (odds ratio [OR] = 4.453, p = 0.031), and staghorn calculi were independent risk factors for postoperative residual calculi (OR = 31.393, p = 0.001).

Conclusion

PCNL was shown to be safe and effective for elderly patients aged > 70 years. Further, ASA III was an independent risk factor for postoperative complications, and staghorn calculi were independent risk factors for postoperative residual calculi in elderly patients.

Ultramini-percutaneous nephrolithotomy versus retrograde intrarenal surgery in the treatment of 10-30 mm calculi: a randomized controlled trial

The surgical management of renal stones 10-30 mm is usually performed with percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS). Standard form of percutaneous nephrolithotomy has paved the way for miniaturized PCNL in many centres. We wanted to evaluate the efficacy, safety and the cost-effectiveness of ultramini-percutaneous nephrolithotomy (UMP) versus RIRS in the treatment of renal stones with stone burden 10-30 mm. Patients with renal stone burden 10-30 mm were prospectively randomized into either UMP or RIRS. The demographic data, stone characteristic, operative time and cost of the equipment were recorded. The stone free status, analgesic requirement, deterioration of the renal function and hemoglobin and the postoperative complications as per Clavein-Dindo grade were recorded. One hundred and fifty patients met inclusion criteria. Out of these 98 underwent UMP and 46 RIRS. Six withdrew the consent before the procedure. Mean stone size was comparable in either of the groups. Mean laser time and stone extraction time was significantly less for UMP compared to RIRS (41.17 min versus 73.58 min p < 0.0001). Mean consumable costs in the UMP group were considerably less at US$45.73 compared to the RIRS group at $423.11 (p < 0.0001). The stone free rates at 1 month of follow-up were 100% for UMP group and 73% for RIRS group. There were insignificant changes to mean hemoglobin and glomerular filtration rate (GFR) in all patients and the average length of the stay was similar in both the groups. The postoperative complications revealed Grade I and II rate of 10% in the UMP group and 35% in the RIRS group, respectively. We concluded that UMP to be safe, effective and more economical to the RIRS for renal stones up to 3 cm in size.Trial registered with ISRCTN registry ID ISRCTN20935105, Retrospective.

Comparison of the Efficacy of ShuoTong Ureteroscopy and Simple Flexible Ureteroscopy in the Treatment of Unilateral Upper Ureteral Calculi

Background: ShuoTong ureteroscopy (Sotn-ureteroscopy, ST-URS), a new lithotripsy operation method developed on the basis of ureteroscopy, is widely used to treat ureteral stones in China. Its composition includes rigid ureteral access sheath, standard mirror, lithotripsy mirror, and ShuoTong perfusion aspirator (ST-APM). Here, we compared the efficacy and safety of the ST-URS and the flexible ureteroscope (F-URS) holmium laser lithotripsy in the treatment of unilateral upper ureteral calculi. Methods: Retrospective analysis was conducted on the clinical data of 280 patients who met the inclusion 1) urinary tract CT was diagnosed with unilateral single upper ureteral calculi above the L4 lumbar spine; 2) patient age was from 18 to 80 years old; 3) patients were informed and consented to this study; and 4) patients were approved by the hospital ethics committee (proof number: KY-2019-020) and the exclusion criteria for unilateral upper ureteral calculi in the First Affiliated Hospital of Xiamen University from January 2018 to November 2020, and they were divided into the ST-URS group and the flexible ureteroscopy (F-URS) group. Results: The stone-free rate of 1 day after operation of the ST-URS group was significantly higher than the F-URS group (63.71 vs. 34.62%, P < 0.0001). The operative time (38.45 vs. 46.18 min, P = 0.005) and hospitalization cost (27,203 vs. 33,220 Yuan, P < 0.0001) of the ST-URS group were significantly lower than the F-URS group. There were no significant differences in the success rate of ureteral access sheath placement, operative blood loss, stone-free rate of 1 month after operation, postoperative complications, postoperative hospital stay, and postoperative visual analog scale (VAS) pain score between the two groups (P > 0.05). In subgroups of a diameter of calculi ≥ 1.5 cm, calculi CT numerical value ≥ 1,000 Hounsfield unit and the preoperative hydronephrosis range ≥ 3.0 cm, ST-URS shows more advantages in the operative time, stone-free rate of 1 day after the operation, the hospitalization cost, and the incidence of postoperative complications. Conclusion: In unilateral upper ureteral stones treated with a holmium laser, compared with the simple F-URS, the ST-URS has a shorter operative time, lower hospitalization cost, and a higher stone-free rate of 1 day after the operation, suggesting that the ST-URS could be more widely applied in clinics.

Low Body Mass Index as a Predictive Factor for Postoperative Infectious Complications after Ureterorenoscopic Lithotripsy

Background and Objectives: In this study, we aimed to evaluate predictive factors of postoperative fever (POF) after ureterorenoscopic lithotripsy (URSL). Materials and Methods: A total of 594 consecutive patients who underwent URSL for urinary stone disease at Gifu Municipal Hospital and Chuno Kosei Hospital between April 2016 and January 2021 were enrolled in this study. In all patients, antibiotics were routinely administered intraoperatively and the next day after surgery. We used rigid and/or flexible ureterorenoscopes depending on the stone location for URSL. Stones were fragmented using a holmium: YAG laser. The fragments of the stone were manually removed as much as possible using a stone basket catheter. A ureteral stent was placed at the end of the surgery in all cases. Results: The median age and body mass index (BMI) in all patients were 62 years and 23.8 kg/m², respectively. The median operation duration was 52 min. The most common URSL-related complication was POF in 28 (4.7%) patients. In these patients, the rates of antibiotic administration and ureteral stent insertion before surgery were significantly higher than in those without POF. In multivariate analysis, BMI was associated with POF after URSL. There were no significant differences in predicting POF after surgery in patients who had bacteriuria or received antibiotics before surgery. Conclusions: A low BMI was significantly associated with POF after URS or URSL.

Stone free rate and clinical complications in patients submitted to retrograde intrarenal surgery (RIRS): Our experience in 571 consecutive cases

INTRODUCTION

The purpose of this study is to report the stone free rate (SFR) and clinical complications in patients submitted to retrograde intrarenal surgery (RIRS).

MATERIALS AND METHODS

A total of 571 procedures of upper urinary stones treated using flexible ureteroscopy and holmium laser lithotripsy from January 2014 to February 2020 have been analyzed. Overall SFR was evaluated after 3 months following the procedure by means of a non-contrast computed tomography. Success was considered as stone-free status or ≤ 0.4 cm fragments.

RESULTS

The overall SFR was 92.3% in group 1 (stone size: < 1 cm), 88.3% in group 2 (stone size: > 1 ≤ 2 cm), 56.7% in group 3 (stone size: 2-3 cm) and 69.6% in group 4 (multiple stones). Post-operative complications, according to the Clavien- Dindo (CD) classification system, were recorded in 32 (5.6%) procedures. The major complications recorded were: one case of subcapsular hematoma (SRH) associated with pulmonary embolism two days after the procedure (CD Grade IIIa) treated conservatively and one case of hemorrhagic shock 2 hour with multiple renal bleedings requiring urgent nephrectomy (CD Grade IVA).

CONCLUSIONS

The RIRS is an effective and safe procedure with a high SFR significantly correlated with the stone size; at the same time, RIRS could be characterized by severe clinical complications that require rapid diagnosis and prompt treatment.

A comparative study of minimally invasive percutaneous nephrolithotomy and retrograde intrarenal surgery for solitary renal stone of 1-2 cm

Background:

PCNL is the treatment of choice for renal stones. But wide array of complications due to larger tract size(>20 Fr) has lead to development of improved techniques like miniPCNL(<20 Fr) and RIRS(Retrograde intrarenal surgery).

Aim and Objective:

To perform a study comparing miniPCNL with RIRS for renal stones 1-2 cm with respect to stone free rate , complications and quality of life.

Materials and Methods:

A prospective, randomised study was carried out our tertiary care centre, recruiting 40 patients in each group from Dec 2016 to Oct 2018. Patients demographic characteristics, operative findings, surgical outcomes and quality of life( SF-36 questionnaire) were recorded with 3 months of follow-up.

Results:

RIRS has longer operative time (69.75 min > 51.58 min; p=0.003), lesser radiation exposure (p=0.012), shorter hospital stay (p =0.15), lesser blood loss and lesser post operative pain on POD1 and POD2 (p =0.005, p=0.001 respectively). RIRS group patients sufferred more post op complications (p=0.03 )of which urosepsis was most common. Stone free rate is significantly better(p =0.003) in miniPCNL group on POD1 , while SFR's at 1 month (miniPCNL-90% and RIRS -85%) and 3 month (miniPCNL- 92.5% and RIRS -87.5%) was better in miniPCNL group, but statistically insignificant.On subgroup analysis SFR in lower pole calculus was better in miniPCNL group at 1month and 3 month (p=0.008). Second intervention for stone clearance was required in 3 patients of miniPCNL and 5 patients of RIRS, out of which 4 had lower pole stone.No significant differnce was found in quality of life in both groups at 1 month.

Conclusion:

MiniPCNL is a better treatment modality for higher single step stone free rate, shorter operative time and fewer postop complication. RIRS has SFR slightly less than miniPCNL but has less radiation exposure and much less post operative pain. There is no significant difference in quality of life in both groups.

The comparison of perioperative outcomes between percutaneous nephrolithotomy and retrograde intrarenal surgery in elderly patients

OBJECTIVES

In this study, we aimed to compare the outcomes and complication rates of percutaneous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS) in elderly patients.

MATERIALS AND METHODS

Between April 2011 and January 2020, patients who underwent PCNL and RIRS for renal stone in elderly patients were retrospectively evaluated. The two groups' perioperative values, stone-free rates and complication rates were compared. Post-operative complications were noted according to the Clavien scoring system.

RESULTS

There were 89 and 72 patients in the PCNL and RIRS group respectively. The median age was 67 years in both the groups (P = .192). The stone size were 22.2 ± 3.5 mm and 19.9 ± 7.1 mm in the PCNL and RIRS group, respectively (P = .082). Stone-free rates were significantly higher in PCNL group (P = .021, P = .034). Also we found that overall complication and major complication rates were significantly higher in PCNL group (P = .016, P = .029).

CONCLUSION

Despite there was higher stone clearance in PCNL, the complication rates were higher compared with RIRS. So RIRS might be a safe alternative treatment method to PCNL in older patients.

The best treatment approach for lower calyceal stones ≤ 20 mm in maximal diameter: mini percutaneous nephrolithotripsy, retrograde intrarenal surgery or shock wave lithotripsy. A systematic review and meta-analysis of the literature conducted by the European Section of Uro-Technology and Young Academic Urologists

INTRODUCTION

The highest in quality data in the literature which compared mini percutaneous nephrolithotripsy (mPCNL), retrograde intrarenal surgery (RIRS) and shock wave lithotripsy (SWL) for the management of lower pole stone (LPS) with a maximal diameter ≤20mm were investigated by means of systematic review (SR) and meta-analysis.

EVIDENCE ACQUISITION

A SR of the literature was conducted on PubMed®, Cochrane, SCOPUS® and EMBASE® in January 2020. The study complied with the PRISMA statement and recommendations of the EAU Guidelines office. Only randomized controlled trials (RCTs) comparing retrograde intrarenal surgery (RIRS), shock wave lithotripsy (SWL) and mini-percutaneous nephrolithotripsy (mPCNL) were selected for the meta-analysis. The endpoints were the efficacy of each modality, measured by stone-free rate (SFR), operative time and retreatment rate and the safety of each method, based on hospitalization time and complications. Subgroup analyses for stones with a maximal diameter <10mm and 10-20 mm were performed.

EVIDENCE SYNTHESIS

Twenty-one RCTs were included in the meta-analysis. mPCNL had the highest SFR and the lowest retreatment rate among the three modalities, while SWL had the lowest SFR and the highest retreatment rate. The operative and hospitalization time were shorter in the case of SWL, whereas they were similar in the case of mPCNL and RIRS. The highest complication rate was observed in mPCNL group, which accounted for 8.3-22.4%, while RIRS and SWL had similar complication rates, which ranged between 1.3-31.4% and 0-48.5%, respectively. Further classification of the complications according to Clavien-Dindo system revealed that SWL had lower grade II complication rates compared to mPCNL and RIRS. Regarding stones <10mm, SWL and RIRS had similar SFR, complication rate, operation and hospitalization time. SWL had higher retreatment rate.

CONCLUSIONS

For LPSs ≤20mm, mPCNL provides the highest SFR and the lowest retreatment rate. This modality has a higher complication rate and longer hospital stay in comparison to the other modalities. SWL provides the lowest SFR with the highest retreatment rate. RIRS has similar complication rate to SWL and could be preferred over SWL. For stones up to 10mm, SWL may provide a valid alternative. Despite a higher retreatment rate, its SFR is similar to RIRS.

Comparison of Retrograde Intrarenal Surgery and Micro-Percutaneous Nephrolithotomy for Kidney Stones: A Meta-Analysis

BACKGROUND

Advances in micro-percutaneous nephrolithotomy (PCNL) for kidney stones have made it an alternative approach to the retrograde intrarenal surgery (RIRS) approach. Nevertheless, the superiority of micro-PCNL over RIRS is still under debate. The results are controversial.

OBJECTIVES

The purpose of this study was to systematically evaluate the clinical results in patients presenting with kidney stones treated with micro-PCNL or RIRS.

METHODS

A literature search was done for electronic databases to identify researches that compared micro-PCNL and RIRS till December 2019. The clinical outcome included complications, stone-free rates (SFRs), hemoglobin reduction, length of hospital stay, and operative time.

RESULTS

Five articles were included in our study. The pooled results revealed no statistical difference in the rate of complications (OR = 0.99, 95% CI = 0.57-1.74, p = 0.99), length of hospital stay (MD = -0.29, 95% CI = -0.82 to 0.24, p = 0.28), and operative time (MD = -6.63, 95% CI = -27.34 to 14.08, p = 0.53) between the 2 groups. However, significant difference was present in hemoglobin reduction (MD = -0.43, 95% CI = -0.55 to 0.30, p < 0.001) and the SFRs (OR = 0.59, 95% CI = 0.36-0.98, p = 0.04) when comparing RIRS with micro-PCNL.

CONCLUSIONS

Compared with micro-PCNL to treat kidney stones, RIRS is associated with better stone clearance and bearing higher hemoglobin loss. As the advantages of both technologies have been shown in some fields, the continuation of well-designed clinical trials may be necessary.

Percutaneous nephrolithotomy versus flexible ureteroscopic lithotripsy in the treatment of upper urinary tract stones: a meta-analysis comparing clinical efficacy and safety

BACKGROUND

Upper urinary tract stones is the most common diseases in urology. Percutaneous nephrolithotomy (PCNL) and ureteroscopic lithotripsy (fURL) are common treatment, but both their efficacy and safety are controversial. Thus we aim to evaluate the efficacy and safety of PCNL and fURL in the treatment of upper urinary tract stones, providing a reference for clinical work.

METHODS

PubMed, Web of Science, Embase and CNKI were searched through Apr. 1, 2019 to identify eligible studies. Data were analyzed by using RevMan 5.3 and Stata 12.0 software. Pooled relative risks (RRs) or weighted mean difference (WMD) with 95% confidence intervals (CIs) were calculated using fixed or random effects methods. Publication bias and sensitivity analysis were performed.

RESULTS

Four randomized controlled trials (RCTs), fifteen cohort studies involving 1822 patients were included. Stone-free rate of PCNL was significantly high than that of fURL (RR: 1.07; 95% CI: 1.03, 1.12; P = 0.0004). The decline of hemoglobin in PCNL was significantly high than that of fURL (WMD: 1.07; 95% CI: 0.54, 1.61; P < 0.0001). The number of blood transfusion was significantly greater in the PCNL compared to the fURL (RR: 5.04; 95% CI: 1.78, 14.24; P = 0.002). The incidence of postoperative bleeding or hematuria showed greater significantly difference in the PCNL compared to the fURL (RR: 2.72; 95% CI: 1.55, 4.75; P = 0.0005). Operation time, fever, infection, perforation, requiring drug analgesia was not significantly different between two surgical procedures.

CONCLUSIONS

In the treatment of upper urinary tract stones, the stones clearance rate of PCNL is higher than fURL, and the safety of fURL is higher than PCNL.

Two-shift operation mode can improve the efficiency and comfort of flexible ureteroscopic holmium laser lithotripsy for the treatment of renal calculi larger than 1.5cm

Purpose:

To compare two-shift operation mode and single player mode different impact on surgical results and operator comfort in flexible ureteroscopic holmium laser lithotripsy for renal calculi larger than 1.5cm.

Materials and Methods:

From december 2017 to december 2018, 92 patients with renal calculi admitted to Qilu Hospital and were treated through flexible ureteroscopy. They were randomized in two-shift group (n=50) and single player group (n=42). The operative time, blood loss, hospitalization stay after operation, residual fragments (≥4mm) rate, fragmentation speed, postoperative complications and operator's fatigue score were compared.

Results:

There was no significant difference between two groups regarding age, gender, illness side, stone size, blood loss, operative time, postoperative hospitalization stay, complications, etc (p >0.05). The fragmentation speed was 44.5±20.0mm3/min in two-shift group compared with 34.2±17.3mm3/min in single player group (p=0.037). Residual fragments (≥4mm) rate after first surgery was 18% in two-shift group, while the residual fragments (≥4mm) rate was 40.5% after first surgery in single player group (p=0.017). The total fatigue score of two-shift group was 8.4 compared to 29.9 in single player group (p <0.001).

Conclusion:

In flexible ureteroscopic holmium laser lithotripsy for the treatment of renal calculi larger than 1.5cm, two-shift operation mode can raise the fragmentation speed and stone clearance rate, as well as significantly lower operator's fatigue level and improve operator's comfort.

A Novel Semirigid Ureterorenoscope with Vacuum Suctioning System for Management of Single Proximal Ureteral and Renal Pelvic Stones: An Initial Experience

INTRODUCTION

A novel semirigid ureterorenoscope, named the Sotn ureterorenoscope, was designed with a vacuum suction system. The present study aimed to evaluate the feasibility and safety of using the Sotn ureterorenoscope to manage single proximal ureteral or renal pelvic stones.

PATIENTS AND METHODS

Data were retrospectively collected from consecutive patients treated with a Sotn ureterorenoscope between February 2010 and August 2015 at Sun Yat-sen Memorial Hospital of Sun Yat-sen University and Jiangmen Wuyi Traditional Chinese Medicine Hospital in China. The primary outcome was the primary stone-free rate (SFR) in 1 month. The secondary outcomes were the final SFR and the perioperative complication rate.

RESULTS

A total of 386 patients were evaluated, including 240 males and 146 females. The median (interquartile range [IR]) age was 50 (40-59) years. There were 96 and 290 stones located in the renal pelvis and proximal ureter, respectively. The median (IR) operative time and console time for all patients were 40 (30-70) and 20 (12-38) minutes, respectively. The primary overall SFR was 86.5%, whereas the SFRs for stones with a diameter of ≤1, 1 to 2, and 2 to 3 cm were 95.7%, 86.9%, and 69.0%, respectively. Complications occurred in 90 patients (23.3%); these complications were classified as Clavien-Dindo grades 1 to 2 (minor) in 79 (20.5%) patients, and grades 3 to 4 (major) in 11 (2.8%).

CONCLUSIONS

The novel semirigid Sotn ureterorenoscope featuring a vacuum suction system is effective and safe for managing proximal ureteral and renal pelvic stones.

Minimally invasive percutaneous nephrolithotomy versus retrograde intrarenal surgery in surgical management of upper urinary stones - A systematic review with meta-analysis

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.

Treatment of Complex Renal Calculi by Digital Flexible Ureterorenoscopy Combined with Single-Tract Super-Mini Percutaneous Nephrolithotomy in Prone Position: A Retrospective Cohort Study

Background

Advances in percutaneous nephrolithotomy (PCNL) have resulted in smaller devices that cause less trauma and bleeding, while flexible ureterorenoscopy (f-URS) allows access to any calyces. These methods are often used in isolation, but used in combination they may improve treatment of complex renal calculi. This study assessed the effectiveness and complications of f-URS combined with super-mini-PCNL (SMP) to treat complex renal calculi.

Material/Methods

A retrospective cohort analysis was made of patients with unilateral complex renal stones treated between March 2013 and December 2016. Patients were grouped according to surgical procedure: SMP (SMP Group), f-URS holmium laser lithotripsy (f-URS Group), and combined SMP and f-URS (Combined Group). The postoperative complications and complete stone-free rate were analyzed and compared among the 3 groups.

Results

A total of 140 patients with complex renal stones were included: 40 patients in the SMP Group, 55 in the f-URS Group, and 45 in the Combined Group. The complete stone-free rate 3 days after the procedure was 77.5% in the SMP Group, 78.2% in the f-URS Group, and 97.8% in the Combined Group (p=0.010). The operation time, intraoperative blood loss, and hospitalization time of the Combined Group were all significantly lower than those in the SMP Group but higher than those in the f-URS Group. The follow-up was 9 months (range, 6–12 months). There were no medium-term complications reported.

Conclusions

SMP combined with f-URS holmium laser lithotripsy in the prone position is an effective treatment for complex renal calculi.

The Comparison Study of Flexible Ureteroscopic Suctioning Lithotripsy With Intelligent Pressure Control Versus Minimally Invasive Percutaneous Suctioning Nephrolithotomy in Treating Renal Calculi of 2 to 3 cm in Size

Purpose. To compare the efficacy and safety of flexible ureteroscopic suctioning lithotripsy (FURS) using patented designed intelligent irrigation and suctioning intraluminal pressure-control platform and integrated pressure-measuring suctioning ureteral access sheath versus minimally invasive suctioning percutaneous nephrolithotomy (MPCNL) in treating renal calculi at 2 to 3 cm in size. Methods. Ninety-one patients who met the criteria were included in the study. Among these, 46 patients underwent transurethral flexible ureteroscopic lithotripsy and the other 45 patients underwent MPCNL. We retrospectively analyzed the clinical data for the 2 groups and parameters including stone clearance rate, complication rate, average operative time, average postoperative hospitalization duration, and average postoperative hemoglobin level decrease were compared. Results. The hospitalization time for the FURS group was 3.53 ± 1.25 days, which was statistically shorter than that of the MPCNL group, which was 6.54 ± 2.36 days. There was significantly more patients needing pain medication postoperatively in the MPCNL group with statistical difference between the 2 groups ( P = .015). Also, there was more significant hemoglobin level drop in the MPCNL group with statistical difference between the 2 groups. However, there were no statistical differences between the 2 groups on average operative time and stone clearance rate. Conclusion. Both the operative methods are safe and efficacious in treating solitary renal calculus at 2 to 3 cm in size. However, FURS has more advantages including shorter hospital stay, less complication, and less bleeding.

The Urological Association of Asia clinical guideline for urinary stone disease

The Urological Association of Asia, consisting of 25 member associations and one affiliated member since its foundation in 1990, has planned to develop Asian guidelines for all urological fields. The field of stone diseases is the third of its guideline projects. Because of the different climates, and social, economic and ethnic environments, the clinical practice for urinary stone diseases widely varies among the Asian countries. The committee members of the Urological Association of Asia on the clinical guidelines for urinary stone disease carried out a surveillance study to better understand the diversity of the treatment strategy among different regions and subsequent systematic literature review through PubMed and MEDLINE database between 1966 and 2017. Levels of evidence and grades of recommendation for each management were decided according to the relevant strategy. Each clinical question and answer were thoroughly reviewed and discussed by all committee members and their colleagues, with suggestions from expert representatives of the American Urological Association and European Association of Urology. However, we focused on the pragmatic care of patients and our own evidence throughout Asia, which included recent surgical trends, such as miniaturized percutaneous nephrolithotomy and endoscopic combined intrarenal surgery. This guideline covers all fields of stone diseases, from etiology to recurrence prevention. Here, we present a short summary of the first version of the guideline - consisting 43 clinical questions - and overview its key practical issues.

Factors affecting infectious complications following flexible ureterorenoscopy

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.

Comparison of suctioning and traditional ureteral access sheath during flexible ureteroscopy in the treatment of renal stones

PURPOSE

To compare the efficiency and safety of suctioning ureteral access sheath (UAS) and traditional UAS during flexible ureteroscopy (FURS) for treatment of renal stones.

METHODS

Between January 2015 and December 2017, 165 patients who had renal stones successfully underwent FURS with suctioning UAS created by connecting a channel on the tail of the suctioning UAS to a vacuum device. The outcomes of these patients were compared with those of 165 patients undergoing FURS with traditional UAS using a 1:1 scenario matched-pair analysis. The matching parameters were age, gender and stone burden.

RESULTS

The baseline characteristics were homogeneous between the two groups. The suctioning UAS group had significantly higher SFR one day postoperatively (82.4% vs. 71.5%; P = 0.02), but SFR 1 month postoperatively was comparable in the two groups (P = 0.13). The incidence of overall complications was significantly higher in the traditional UAS group (24.8% vs 11.5%; P < 0.001). Regarding individual complications, the traditional UAS group was associated with a significantly higher incidence of fever (13.9% vs 5.5%; P = 0.009) and urosepsis requiring only additional antibiotics (6.7% vs 1.8%; P = 0.029). No significant difference was noted in the incidence of septic shock, hematuria, steinstrasse or ureteral stricture. The suctioning UAS group had significantly shorter operative time (49.7 + 16.3 min vs. 57.0 ± 14.0 min; P < 0.001).

CONCLUSIONS

Compared to traditional UAS during FURS for treating renal stones, suctioning UAS had the advantages of higher SFR 1 day postoperatively, a lower incidence of infectious complications and a shorter operative time. Further well-designed studies are required to confirm the results.

Robot-assisted flexible ureteroscopy: an update

The role of flexible ureteroscopy (FURS) in the management of nephrolithiasis has increased due to the improved armamentarium. However, FURS still represents a challenging technique limiting its diffusion. Similar to previous experiences in laparoscopy, recently developed robotic devices may significantly compensate for the ergonomic deficiencies of FURS. Based on a short description of the history of robotic devices for laparoscopy, this article summarizes all current developments of robotic FURS. In 2008, robotic FURS was first reported using the Sensei-Magellan system designed for interventional cardiology. However, with this device the ureteroscope was only passively manipulated, which represented the main reason why this project has been discontinued after 18 clinical cases. Avicenna Roboflex™ was especially developed for FURS. It consists of a surgeon's console and manipulator of a flexible ureterorenoscope. The console provides an adjustable seat with armrests and two manipulators of the endoscope: the right wheel enables deflection and the left horizontal joystick allows rotation as well as advancing and retracting the instrument. The speed of rotation and advancement can be regulated at the screen of the console. Using the IDEAL system for evaluation of new robotic devices, safety and efficacy of the system could be demonstrated in two multi-centric studies providing significant improved ergonomics for the surgeon (IDEAL stage 1 and 2). Future studies are necessary to determine the final role of robotic FURS.

The R.I.R.S. scoring system: An innovative scoring system for predicting stone-free rate following retrograde intrarenal surgery

Background

To establish and internally validate an innovative R.I.R.S. scoring system that allows urologists to preoperatively estimate the stone-free rate (SFR) after retrograde intrarenal surgery (RIRS).

Methods

This study included 382 eligible samples from a total 573 patients who underwent RIRS from January 2014 to December 2016. Four reproducible factors in the R.I.R.S. scoring system, including renal stone density, inferior pole stone, renal infundibular length and stone burden, were measured based on preoperative computed tomography of urography to evaluate the possibility of stone clearance after RIRS.

Results

The median cumulative diameter of the stones was 14 mm, and the interquartile range was 10 to 21. The SFR on postoperative day 1 in the present cohort was 61.5% (235 of 382), and the final SFR after 1 month was 73.6% (281 of 382). We established an innovative scoring system to evaluate SFR after RIRS using four preoperative characteristics. The range of the R.I.R.S. scoring system was 4 to 10. The overall score showed a great significance of stone-free status (p < 0.001). The area under the receiver operating characteristic curve of the R.I.R.S. scoring system was 0.904.

Conclusions

The R.I.R.S. scoring system is associated with SFR after RIRS. This innovative scoring system can preoperatively assess treatment success after intrarenal surgery and can be used for preoperative surgical arrangement and comparisons of outcomes among different centers and within a center over time.

Skin to calyx distance is not a predictive factor for miniaturized percutaneous nephrolithotomy outcomes

Objective

To evaluate the predictive value of the distance from skin to calyx (SCD) on the outcome and complication rates of patients undergoing mPNL.

Materials and Methods

Patient’s charts, who had undergone mPNL between June 2012 and June 2015, were analyzed retrospectively. Patients who had a preoperative computerized tomography (CT) were enrolled into the study. Two separateurologists evaluated the CT scans and calculated the SCD defined as the distance between the skin and surface/lateral edge of the calyx, which was the preferred site of entry for percutaneous access. The average value of the two measurements was included inthe final analysis to avoid bias. The mean SCD was 75mm. According to the median SCD value, patients were divided into two groups: group 1 (SCD ≤75) and group 2 (SCD >75).

Results

A total of 140 patients and 130 patients were enrolled in groups 1 and 2, respectively. The mean operation time and the mean fluoroscopy time was significantly longer in group 2 (p:0.004 vs. p:0.021). The rate of blood transfusion was significantly higher in group 1 (6 patients). None of patientsin group 2required blood transfusion (p:0.017). Stone-free status after a single session of mPNL was 67.1% in group 1 and 75.4% in group 2 (p:0.112). After additional procedures, stone-free rates increased to 84.3% and 85.4% in group 1 and group 2, respectively (p:0.802).

Conclusion

Our study demonstrated that longer SCD was not a predictive factor for stone-free rates after mPNL. However, SCD over 75mm was associated with longer operation time and fluoroscopy time with lower rates of transfusion.

A prospective randomized comparison among SWL, PCNL and RIRS for lower calyceal stones less than 2 cm: a multicenter experience : A better understanding on the treatment options for lower pole stones

PURPOSE

To prospectively evaluate the efficacy and safety of RIRS, SWL and PCNL for lower calyceal stones sized 1-2 cm.

MATERIALS AND METHODS

Patients with a single lower calyceal stone with an evidence of a CT diameter between 1 and 2 cm were enrolled in this multicenter, randomized, unblinded, clinical trial study. Patients were randomized into three groups: group A: SWL (194 pts); group B: RIRS (207 pts); group C: PCNL (181 pts). Patients were evaluated with KUB radiography (US for uric acid stones) at day 10 and a CT scan after 3 months. The CONSORT 2010 statement was adhered to where possible. The collected data were analyzed.

RESULTS

The mean stone size was 13.78 mm in group A, 14.82 mm in group B and 15.23 mm in group C (p = 0.34). Group C compared to group B showed longer operative time [72.3 vs. 55.8 min (p = 0.082)], fluoroscopic time [175.6 vs. 31.8 min (p = 0.004)] and hospital stay [3.7 vs. 1.3 days (p = 0.039)]. The overall stone-free rate (SFR) was 61.8% for group A, 82.1% for group B and 87.3% for group C. The re-treatment rate was significantly higher in group A compared to the other two groups, 61.3% (p < 0.05). The auxiliary procedure rate was comparable for groups A and B and lower for group C (p < 0.05). The complication rate was 6.7, 14.5 and 19.3% for groups A, B and C, respectively.

CONCLUSIONS

RIRS and PCNL were more effective than SWL to obtain a better SFR and less auxiliary and re-treatment rate in single lower calyceal stone with a CT diameter between 1 and 2 cm. RIRS compared to PCNL offers the best outcome in terms of procedure length, radiation exposure and hospital stay. ISRCTN 55546280.

[S2k guidelines on diagnostics, therapy and metaphylaxis of urolithiasis (AWMF 043/025) : Compendium]

Every tenth German citizen will suffer from at least one urinary calculus during the lifetime. The diagnostics, treatment and follow-up treatment of urolithiasis are, therefore, part of the daily routine practice for all urologists in hospitals and private practices as well as in many other disciplines, such as general practitioners, internists, nephrologists and pediatricians. Although the diagnostics and therapy have experienced substantial alterations over the last 10 years, the possibilities of metabolic diagnostics and secondary prevention for patients at risk are, unfortunately and unjustly, in many places very poorly represented. The present S2k guidelines, which for the first time were established in an interdisciplinary consensus process, represent the current practical recommendations and, whenever possible, use tables and algorithms in order to facilitate easy reference in the routine daily work. Last but not least, this greatly simplifies the measures for metaphylaxis.

Minimally Invasive Percutaneous Nephrolithotomy versus Retrograde Intrarenal Surgery for Upper Urinary Stones: A Systematic Review and Meta-Analysis

Minimally invasive percutaneous nephrolithotomy (mini-PCNL) and retrograde intrarenal surgery (RIRS) are both alternatives for PCNL to treat renal calculi. This study is aimed at comparing the stone-free rate (SFR) and other surgery parameters of two approaches for treating upper urinary calculi. We performed this meta-analysis in September 2016 by searching studies about mini-PCNL and RIRS for treating upper urinary calculi in various databases, and RevMan v.5.3 was applied. Three randomized controlled trials and ten nonrandomized trials were included, involving a total of 1317 patients. Meta-analysis showed that mini-PCNL group led to a higher SFR [odds ratio: 1.96; 95% confidence interval: 1.46–2.64; P < 0.00001] but brought a larger postoperative decrease in hemoglobin levels compared with RIRS. RIRS provided a shorter hospital time. There was no significant difference in operation time. Higher postoperative complications were detected in the mini-PCNL, but the difference was not significant. Grade I and III complications did not vary between two procedures, but grade II complications were of lower incidence in RIRS group. In the light of these results, compared with RIRS, mini-PCNL provided significantly higher SFR and efficiency quotient for managing calculi; however, it resulted in higher incidence of postoperative complications, larger hemoglobin drops, and longer hospital stay.

Tract Sizes in Miniaturized Percutaneous Nephrolithotomy: A Systematic Review from the European Association of Urology Urolithiasis Guidelines Panel

CONTEXT

Miniaturized instruments for percutaneous nephrolithotomy (PNL), utilizing tracts sized ≤22 Fr, have been developed in an effort to reduce the morbidity and increase the efficiency of stone removal compared with standard PNL (>22 Fr).

OBJECTIVE

We systematically reviewed all available evidence on the efficacy and safety of miniaturized PNL for removing renal calculi.

EVIDENCE ACQUISITION

The review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement. Since it was not possible to perform a meta-analysis, the data were summarized in a narrative synthesis.

EVIDENCE SYNTHESIS

After screening 2945 abstracts, 18 studies were included (two randomized controlled trials [RCTs], six nonrandomized comparative studies, and 10 case series). Thirteen studies were full-text articles and five were only available as congress abstracts. The size of tracts used in miniaturized procedures ranged from 22 Fr to 4.8 Fr. The largest mean stone size treated using small instruments was 980mm². Stone-free rates were comparable in miniaturized and standard PNL procedures. Procedures performed with small instruments tended to be associated with significantly lower blood loss, while the procedure duration tended to be significantly longer. Other complications were not notably different between PNL types. Study designs and populations were heterogeneous. Study limitations included selection and outcome reporting bias, as well as a lack of information on relevant confounding factors.

CONCLUSIONS

The studies suggest that miniaturized PNL is at least as efficacious and safe as standard PNL for the removal of renal calculi. However, the quality of the evidence was poor, drawn mainly from small studies, the majority of which were single-arm case series, and only two of which were RCTs. Furthermore, the tract sizes used and types of stones treated were heterogeneous. Hence, the risks of bias and confounding were high, highlighting the need for more reliable data from RCTs.

PATIENT SUMMARY

Removing kidney stones via percutaneous nephrolithotomy (PNL) using smaller sized instruments (mini-PNL) appears to be as effective and safe as using larger (traditional) instruments, but more clinical research is needed.

Use of a Novel Flexible Mini-nephroscope in Minimally Invasive Percutaneous Nephrolithotomy

OBJECTIVE

To assess the feasibility and safety of a novel flexible mini-nephroscope in minimally invasive percutaneous nephrolithotomy (PCNL). Presumably, limiting the size and number of tracts during PCNL has the potential of decreasing the morbidity of the procedure. We present our experience with this new technique.

MATERIALS AND METHODS

A retrospective analysis of patients with multiple kidney stones treated with mini-PCNL combined with a novel flexible mini-nephroscope was performed. Minimally invasive PCNL was done with rigid 12 F MIP-M nephroscope, followed by flexible mini-nephroscopy for smaller stones in other inaccessible calyces. Record was made of the operating time, stone-free rates, postoperative pain, morbidity, hospital stay, time to recovery, complication rates, and ancillary procedures. Matched-pair analysis was done with cases operated by flexible ureteroscopy performed with Flex X-2 or Flex X-c scope.

RESULTS

Twenty-five patients in the study group were matched with 25 cases from the flexible ureteroscopy group. Both groups were comparable in terms of age, laterality, and mean composite stone burden. The mean operating time was 40.1 ± 10.6 minutes in the mini-PCNL group and 51.2 ± 8.8 minutes in the flexible ureteroscopy group. Mean hospital stay was similar in both groups. The primary stone clearance rate of 92% (23 of 25) in the mini-PCNL group was better than the clearance rate of 80% (20 of 25) in the flexible ureteroscopy group. Eight percent in the mini-PCNL group required ancillary procedures as compared with 20% of cases in the flexible ureteroscopy group. Postoperative pain and analgesia requirement in these patients was minimal. There were no significant complications.

CONCLUSION

Flexible mini-nephroscope is an effective adjuvant to minimally invasive PCNL in achieving high clearance rate with minimum morbidity.

Current Standard Technique for Modern Flexible Ureteroscopy: Tips and Tricks

BACKGROUND

Thanks to advancements in the endoscopic armamentarium, flexible ureteroscopy (fURS) has become a viable and attractive option for the treatment of renal stones because of its high stone-free rates (SFRs) and low morbidity.

OBJECTIVE

To describe our surgical technique for fURS, step-by-step, for the treatment of renal stones and to assess its effectiveness and safety.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective analysis of 316 consecutive patients who underwent fURS for renal stones at our institution between March 2014 and September 2015 was performed.

SURGICAL PROCEDURE

Ureteroscopy and laser lithotripsy using a standardized technique with last-generation flexible ureteroscopes.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Clinical data were collected in a dedicated database. Intraoperative and postoperative outcomes were assessed. A descriptive statistical analysis was performed.

RESULTS AND LIMITATIONS

The mean overall stone size was 16.5 ± 7.9mm. Ureteral access sheath placement was possible in 287 patients (90.8%). At 1-mo follow-up, the overall primary SFR was 79.1%; the secondary and tertiary SFRs were 89.5% and 91.5%, respectively. The mean operative time was 72.6 ± 27.5min. The mean number of procedures was 1.27. Complications were reported in 92 patients (29.1%) overall, with Clavien grade 1 in 55 patients (17.4%), grade 2 in 30 patients (9.5%), grade 3 in 6 patients (1.9%), grade 4 in 1 patient (0.3%), and grade 5 in none. The main limitation of the study was the retrospective nature.

CONCLUSIONS

The fURS procedure is safe and effective for the treatment of renal stones. A staged procedure is necessary to achieve stone-free status with large calculi.

PATIENT SUMMARY

Flexible ureteroscopy is an effective treatment with low complication rates for the majority of renal stones. Both the modern highly technological armamentarium and surgical know-how should be available.

Comparison of miniaturized percutaneous nephrolithotomy and flexible ureterorenoscopy for the management of 10-20 mm renal stones in obese patients

PURPOSE

To evaluate and compare effectivity and safety of flexible ureteroscopy (F-URS) and mini-percutaneous nephrolithotomy (mPNL) for 10-20 mm renal stones in obese patients.

METHODS

Between 2012 and 2015, charts of patients who were treated with F-URS or mPNL for 10-20 mm kidney stone(s) were analyzed. Patients with BMI > 30 kg/m(2) were enrolled into the study. Total of 315 patients were treated with mPNL, and 56 patients were matched our inclusion criteria. In the same period, F-URS was performed in 669 patients, and 157 of them had 10-20 mm kidney stones, and their BMI values were >30 kg/m(2). The patients were retrospectively matched at a 1:1 ratio to index F-URS-mPNL cases with respect to the patient age, gender, ASA score, BMI and size, number, and location of stone.

RESULTS

Gender, age, BMI, stone size, stone number, location of stone(s), and ASA scores were similar between groups. The mean operation time was significantly longer in mPNL group (p: 0.021). However, the mean fluoroscopy time was similar (p: 0.270). Hemoglobin drop requiring blood transfusion and angioembolization was performed in two and one patients after mPNL, respectively. Overall complication rate was significantly higher in mPNL group than F-URS group (30.3 vs. 5.3 %, p: 0.001).

CONCLUSION

Our results demonstrated that both F-URS and mPNL achieve acceptable stone-free rates in obese patients with 10-20 mm renal stones. However, complication rates were significantly lower in F-URS group.

Clinical significance of residual fragments in 2015: impact, detection, and how to avoid them

PURPOSE

Residual fragments are common after stone treatment. Little is known about clinical outcomes relevant to the patient. This comprehensive review of the literature highlights the impact of residual fragments, modes of detection, and treatment strategies to avoid residual fragments in shock wave therapy, ureteroscopy, and percutaneous nephrolithotomy.

METHODS

A comprehensive review of current literature was performed using PubMed(®), MEDLINE(®), Embase™, Ovid(®), Google Scholar™, and the Cochrane Library. Publications relevant to the subject were retrieved and critically appraised.

RESULTS

Residual fragments after treatment for urinary stones have a significant impact on a patient's well-being and future course. (Ultra-) low-dose non-contrast computed tomography detects small residuals most reliably. In shock wave lithotripsy, adherence to basic principles helps to improve results. Various techniques and devices facilitate complete stone clearance in conventional and miniaturized percutaneous nephrolithotomy and (flexible) ureteroscopy. Promising new technologies in shock waves, lasers, and robotics (and potentially microrobotics) are on the horizon.

CONCLUSIONS

Residual fragments are relevant to patients. Contemporary treatment of urolithiasis should aim at complete stone clearance.

Recent advancement or less invasive treatment of percutaneous nephrolithotomy

Since its initial introduction in 1976, percutaneous nephrolithotomy (PCNL) has been widely performed for the management of large renal stones and currently is recommended for staghorn calculi, kidney stones larger than 2 cm, and shock wave lithotripsy-resistant lower pole stones greater than 1 cm. However, except for open and laparoscopic surgery, PCNL is the most invasive of the minimally invasive stone surgery techniques. Over the years, technical and instrumental advances have been made in PCNL to reduce morbidity and improve effectiveness. A thorough review of the recent literature identified five major areas of progress for the advancement of PCNL: patient positioning, method of percutaneous access, development of lithotriptors, miniaturized access tracts, and postoperative nephrostomy tube management. This review provides an overview of recent advancements in PCNL and the outcomes of each area of progress and notes how much we achieve with less invasive PCNL. This information may allow us to consider the future role and future developments of PCNL.

EAU Guidelines on Interventional Treatment for Urolithiasis

CONTEXT

Management of urinary stones is a major issue for most urologists. Treatment modalities are minimally invasive and include extracorporeal shockwave lithotripsy (SWL), ureteroscopy (URS), and percutaneous nephrolithotomy (PNL). Technological advances and changing treatment patterns have had an impact on current treatment recommendations, which have clearly shifted towards endourologic procedures. These guidelines describe recent recommendations on treatment indications and the choice of modality for ureteral and renal calculi.

OBJECTIVE

To evaluate the optimal measures for treatment of urinary stone disease.

EVIDENCE ACQUISITION

Several databases were searched to identify studies on interventional treatment of urolithiasis, with special attention to the level of evidence.

EVIDENCE SYNTHESIS

Treatment decisions are made individually according to stone size, location, and (if known) composition, as well as patient preference and local expertise. Treatment recommendations have shifted to endourologic procedures such as URS and PNL, and SWL has lost its place as the first-line modality for many indications despite its proven efficacy. Open and laparoscopic techniques are restricted to limited indications. Best clinical practice standards have been established for all treatments, making all options minimally invasive with low complication rates.

CONCLUSION

Active treatment of urolithiasis is currently a minimally invasive intervention, with preference for endourologic techniques.

PATIENT SUMMARY

For active removal of stones from the kidney or ureter, technological advances have made it possible to use less invasive surgical techniques. These interventions are safe and are generally associated with shorter recovery times and less discomfort for the patient.

Miniperc and retrograde intrarenal surgery: when and how?

CONTEXT

Extracorporeal shock wave lithotripsy (ESWL) and percutaneous nephrolithotomy (PCNL) are consolidated procedures for the treatment of kidney stones; however, their primary weak points are the lower efficacy of ESWL, especially for lower calyx stones, and the morbidity of PCNL resulting from the creation and dilation of the percutaneous trajectory. The increasing miniaturization of percutaneous surgery instrumentation and the development of retrograde intrarenal surgery (RIRS) are recent innovations.

ACQUISITION OF EVIDENCE

A structured nonsystematic review was conducted through a literature search of articles published between 1997 and 2013, using the terms kidney stones, miniperc, mini-PCNL, RIRS and flexible ureteroscopy in the PubMed, Google Scholar and Scopus databases.

SUMMARY OF THE EVIDENCE

RIRS requires greater surgical time, several procedures for voluminous stones and higher hospital costs, due in part to the relative fragility of the instruments. On the other hand, miniperc requires a longer hospital stay, an increased need for postoperative analgesia and a greater reduction in hemoglobin levels, although these do not translate into an increased rate of transfusions.

CONCLUSIONS

The current treatment of kidney stones uses minimally invasive procedures such as miniperc and RIRS. The 2 procedures are equivalent in terms of efficacy (stone clearance) and are associated with minimal complications. Comparative prospective studies are necessary to determine the position of each of these techniques in the treatment of kidney stones. In our experience, the 2 techniques are complementary and should be part of the current urological therapeutic arsenal.

Lower pole anatomy and mid-renal-zone classification applied to flexible ureteroscopy: experimental study using human three-dimensional endocasts

PURPUSE

The aim of this study was to analyze the anatomy of the inferior pole collecting system and the mid-renal-zone classification in human endocasts applied to flexible ureteroscopy.

METHODS

170 three-dimensional polyester resin endocasts of the kidney collecting system were obtained from 85 adult cadavers. We divided the endocasts into four groups: A1--kidney midzone (KM), drained by minor calices (mc) that are dependent on the superior or the inferior caliceal groups; A2--KM drained by crossed calices; B1--KM drained by a major caliceal group independent of both the superior and inferior groups; and B2--KM drained by mc entering directly into the renal pelvis. We studied the number of calices, the angle between the lower infundibulum and renal pelvis and the angle between the lower infundibulum and the inferior mc (LIICA). Means were statistically compared using ANOVA and the unpaired T test (p < 0.05).

RESULTS

We found 57 (33.53 %) endocasts of group A1; 23 (13.53 %) of group A2; 59 (34.71 %) of group B1; and 31 (18.23 %) of group B2. The inferior pole was drained by four or more calices in 84 cases (49.41 %), distributed into groups as follows: A1 = 35 cases (41.67 %); A2 = 18 (21.43 %); B1 = 22 (26.19 %); and B2 = 9 (10.71 %). Perpendicular mc were observed in 15 cases (8.82 %). We did not observe statistical differences between the LIICA in the groups studied.

CONCLUSIONS

Collector systems with kidney midzone drained by minor calices that are dependent on the superior or on the inferior caliceal groups presented at least two restrictive anatomical features. The mid-renal-zone classification was predictive of anatomical risk factors for lower pole ureteroscopy difficulties.