Standardized flexible ureteroscopic technique to improve stone-free rates

Scoping Review of Experimental and Clinical Evidence and Its Influence on Development of the Suction Ureteral Access Sheath

The ureteral access sheath (UAS) has been a boon and a bane in flexible ureteroscopy (FURS), with its merits and demerits well established. Its design and dimensions were instrumental in reshaping the way flexible scopes were used and were key adjuncts to establishing retrograde intrarenal surgery (RIRS) as a standard of care in the endourological management of renal stones. With the ever-changing landscape of RIRS over the decades shaped by technological advancements in lasers and flexible scopes, the UAS has also continuously evolved. The utility of suction in endourology has recently changed the way RIRS is performed and is a game changer for FURS outcomes. With strong clinical and experimental evidence to support its use, the UAS has undergone a transformative change in the recent past, with its ability to monitor intrarenal pressure and provide a superior vacuum-cleaner effect that improves the trifecta of RIRS, namely an improved single-stage stone-free rate (SFR), minimise complications, and reduce reinterventions. Our comprehensive review outlines the key clinical and experimental evidence and traces the developments that were key to modifying the traditional UAS into a flexible and navigable suction ureteric access sheath (FANS) and highlights how the design and modifications, in turn, influence the ability to push the boundaries of RIRS.

Primary Ureteroscopy without Pre-Stenting for Proximal Ureteral Stones-Is It Feasible?

BACKGROUND

Primary ureteroscopy with laser lithotripsy is the treatment of choice for distal ureteral stones. However, in cases of proximal ureteral stones, some urologists recommend the preliminary insertion of a ureteral stent and deferred ureteroscopy. We aimed to evaluate the necessity of preliminary ureteral stent insertion in the management of proximal ureteral stones by comparing the surgical outcomes of patients undergoing primary ureteroscopy with laser lithotripsy for proximal vs. distal ureteral stones.

METHODS

Medical records of patients who underwent ureteroscopy between 2016 and 2017 in our institution were retrospectively reviewed. Data collected included demographic data, stone size, renal function, intra- and post-operative complications, and stone-free rate (SFR). Patients were divided into two groups: proximal ureteral stones and distal ureteral stones.

RESULTS

The cohort included 241 patients who underwent ureteroscopy. Among them, 106 had a proximal ureteral stone. The median age was 51 (IQR 41-65) years. Patients who underwent ureteroscopy for proximal ureteral stones were significantly older (p = 0.007). The median stone's maximal diameter was 7 (5-10) mm. The complication rate and stone-free rate (SFR) were similar in both groups (p = 0.657 and p = 1, respectively). The prevalence of post-procedural ureteral stent insertion was higher among patients who underwent ureteroscopy for proximal ureteral stones: 92.5% vs. 79.3% (p = 0.004).

CONCLUSIONS

Our study concludes that primary ureteroscopy with laser lithotripsy for proximal ureteral stones is a valid and feasible treatment with a similar surgical outcome compared to distal ureteral stones. Preliminary ureteral stent insertion seems to be unnecessary.

Real-world Practice Stone-free Rates After Ureteroscopy: Variation and Outcomes in a Surgical Collaborative

BACKGROUND

Studies assessing the stone-free rate (SFR) after ureteroscopy are limited to expert centers with varied definitions of stone free. Real-world data including community practices related to surgeon characteristics and outcomes are lacking.

OBJECTIVE

To evaluate the SFR for ureteroscopy and its predictors across diverse surgeons in Michigan.

DESIGN, SETTING, AND PARTICIPANTS

We assessed the Michigan Urological Surgery Improvement Collaborative (MUSIC) clinical registry for patients with renal or ureteral stones treated with ureteroscopy between 2016 and 2021 who had postoperative imaging.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Stone free was defined as no fragments on imaging reports within 60 d entered by independent data abstractors. Factors associated with being stone free were examined using logistic regression, including annual surgeon volume. We then assessed variation in surgeon-level SFRs adjusted for risk factors.

RESULTS AND LIMITATIONS

We identified 6487 ureteroscopies from 164 surgeons who treated 2091 (32.2%) renal and 4396 (67.8%) ureteral stones. The overall SFRs were 49.6% (renal) and 72.7% (ureteral). Increasing stone size, lower pole, proximal ureteral location, and multiplicity were associated with not being stone free. Female gender, positive urine culture, use of ureteral access sheath, and postoperative stenting were associated with residual fragments when treating ureteral stones. Adjusted surgeon-level SFRs varied for renal (26.1-72.4%; p < 0.001) and ureteral stones (52.2-90.2%; p < 0.001). Surgeon volume was not a predictor of being stone free for renal stones. Limitations include the lack of imaging in all patients and use of different imaging modalities.

CONCLUSIONS

The real-world complete SFR after ureteroscopy is suboptimal with substantial surgeon-level variation. Interventions focused on surgical technique refinement are needed to improve outcomes for patients undergoing ureteroscopy and stone intervention.

PATIENT SUMMARY

Results from a diverse group of community practicing and academic center urologists show that for a large number of patients, it is not possible to be completely stone free after ureteroscopy. There is substantial variation in surgeon outcomes. Quality improvement efforts are needed to address this.

Influence of pre-stenting on RIRS outcomes. Inferences from patients of the Global Multicentre Flexible Ureteroscopy Outcome Registry (FLEXOR)

BACKGROUND

Retrograde Intrarenal Surgery (RIRS) is recommended as an alternative to percutaneous nephrolithotomy for stones up to 2 cm. Pre-stenting before RIRS remains controversial with various studies differing in outcomes and recommendations. We aim to understand how pre-stenting influences surgical outcomes.

METHODS

A number of 6579 patients from the TOWER group registry were divided into pre-stented (group 1) and non-pre-stented groups (group 2). Patients aged ≥18 years old, with normal calyceal anatomy were enrolled. Patients with ureteric stones, anomalous kidneys, bilateral stones, planned for ECIRS were excluded.

RESULTS

Patients are homogeneously distributed in both groups (3112 vs. 3467). The predominant indication for pre-stenting was symptom relief. Overall stone size was comparable, whilst group 1 had a significantly more multiple (1419 vs. 1283, P<0.001) and lower-pole (LP) stones (1503 vs. 1411, P<0.001). The mean operative time for group 2 was significantly longer (68.17 vs. 58.92, P<0.001). Stone size, LP stones, age, recurrence and multiple stones are contributing factors for residual fragments at the multivariable analysis. The incidence of postoperative day 1 fever and sepsis was significantly higher in group 2, indicating that pre-stenting is associated with a lower risk of post-RIRS infection and a lower overall complications rate (13.62% vs. 15.89%) (P<0.001).

CONCLUSIONS

RIRS without pre-stenting can be considered safe without significant morbidity. Multiple, lower-pole and large stone is a significant contributor towards residual fragments. Patients who were not pre-stented had significantly higher but low-grade complications, especially for lower pole and large volume stones. While we do not advocate routine pre-stenting, a tailored approach for these patients should include proper counselling regarding pre-stenting.

Can We Identify Patients in Danger of Complications in Retrograde Intrarenal Surgery?-A Retrospective Risk Factors Analysis

Retrograde intrarenal surgery (RIRS) is an innovative and effective method of kidney stones treatment, as it had great influence on the development of endoscopy in urology. The increasing prevalence of urolithiasis together with the rapid development of endourology leads to a rise in the number of procedures related to the disease. Flexible ureteroscopy is constantly being improved, especially regarding the effectiveness and safety of the procedure. The purpose of this study is to evaluate intraoperative and early post-operative complications of RIRS in the treatment of kidney stones. A retrospective analysis of medical records was performed. A series was comprised of 207 consecutive operations performed from 2017 to 2020. Complications occurred in 19.3% (n = 40) of patients. Occurrence according to the Clavien-Dindo scale was: 11.1% for grade I, 5.8% for grade II and 2.4% for grade IV. Infectious complications included SIRS (5.3%, n = 11) and sepsis (2.4%, n = 5). Statistical analysis revealed a correlation between acute post-operative infections and positive midstream urine culture, history of chronic or recurrent urinary tract infections, and increased body mass index (BMI). Furthermore, a significant correlation was observed between pain requiring the use of opioids with BMI over 25. Consequently, history of urinary tract infections, positive pre-operative urine culture, and increased BMI are considered risk factors and require appropriate management.

The Impact of One Week of Pre-stenting on Porcine Ureteral Luminal Circumference

OBJECTIVES

Larger ureteral access sheaths (UAS) have the potential to improve ureteroscopic stone removal outcomes, but are often avoided by surgeons due to concerns of ureteral injury. Using our novel UAS force sensor and previously defined force thresholds for ureteral injury, we sought to evaluate the impact of one week of stenting on the maximum safe dilation of ureteral luminal circumference.

METHODS

Twelve juvenile female Yorkshire pigs (24 ureters) were evaluated. The inner (i.e. luminal) circumference of each ureter was determined using Cook urethral dilators ranging from 8-24Fr in 2Fr increments, 37cm in length. Each dilator was sequentially passed while applying the UAS force sensor to measure insertion force before and after one week of stent placement. Each ureter was randomized to receive either a 4.7Fr or 7.0Fr stent (20cm). Maximum ureteral luminal circumference was defined as successful passage of the dilator to the ureteropelvic junction with <6 newtons (N) of force (the force threshold previously defined by porcine and clinical studies to avoid ureteral damage). Following passage of the largest dilator at 6N, flexible ureteroscopy was performed and a post-ureteroscopic lesion score (PULS) was recorded.

RESULTS

After one week of stent placement, the median ureteral luminal circumference increased to 15Fr representing a mean increase of 3.8Fr + 2.8 (p<0.001). Twenty-one (88%) of the pre-stented ureters had an increase in luminal circumference, with 12 ureters (50%) dilated to >16Fr (p=0.032), six ureters (25%) dilated to >18Fr, and in two cases a maximum size of 24Fr was recorded. The PULS grade was < 2 in all cases, indicating no high grade ureteral injuries. Laterality and stent size did not impact ureteral luminal circumference after pre-stenting (p=0.232 and p=0.337, respectively).

CONCLUSIONS

One week of ureteral stenting resulted in nearly a 4Fr increase in the luminal circumference of porcine ureters.

Efficiency of retrograde intrarenal surgery in lower pole stones: disposable flexible ureterorenoscope or reusable flexible ureterorenoscope?

PURPOSE

The primary aim of this study to comparison of reusable and disposable flexible ureterorenoscope (fURS) efficiency in lower pole renal stone disease management. In addition, the secondary goal of this study was to evaluate the factors affecting stone-free rates (SFR) in lower pole stones.

MATERIALS AND METHODS

A prospective case-control study utilizing data from 122 consecutive ureteroscopic cases. The patients were divided into two groups according to the ureterorenoscope employed in the surgical intervention as disposable fURS (Group1, n:52) and reusable fURS (Group 2, n:70). Demographic characteristics, stone size, infundibulopelvic angle (IPA), SFR, hospitalization time, intraoperative complication rate (CR), operative time, preoperative or postoperative JJ stenting, and postoperative CR were analyzed.

RESULTS

There was no statistical difference between the demographic and renal stone-related data between the groups. Likewise, no difference is observed in term of intraoperative and postoperative outcomes such as fluoroscopy time, CR, and hospitalization time between the groups. Although SFR was higher in the disposable fURS group, there was no difference statistically. However, the operative time was longer in reusable fURS Group (47.02 ± 9.91 min in Group 1, and it was 57.97 ± 14.28 in Group 2) (p: 0.001). The multivariate regression analysis result to evaluate the factors of effect to operative time; the use of disposable fURS was associated with a 10.95-min decrease in procedure duration (p < 0.001).

CONCLUSIONS

Disposable fURS and reusable fURS have similar clinical efficiency and complication rates in the treatment of lower calyceal stones with RIRS. Nevertheless, disposable fURS is a useful treatment option for increased stone volume due to the advantages such as shorter operative time.

Examining the Impact of Different Properties of Ureteral Access Sheaths in Reducing Insertion Force during Retrograde Intrarenal Surgery: An In Vitro Study

BACKGROUND AND PURPOSE

This study aimed to evaluate the characteristics of ureteral access sheaths (UASs) that can reduce the insertion force while accessing the upper urinary tract.

MATERIALS AND METHODS

Six different types of 12/14-Fr UASs were used. We evaluated the properties of UASs such as the diameter of the outer sheath, length of the inner dilator tip exposed from the outer sheath, sheath flexibility (assessed in terms of bending force of the tip or base), flexibility ratio (i.e., bending force value of tip-to-base ratio), and frictional force of the outer sheath surface. We measured the force required for inserting the UAS into an artificial ureteral model and examined the correlation between the relevant characteristics and insertion force for each UAS.

RESULTS

Overall, a lower tip-to-base flexibility ratio (r = 0.66) and a lower frictional force (r = 0.50) were inversely correlated with insertion force. The force of insertion into the bifurcation was associated with the flexibility of the base (r = -0.64), flexibility ratio (r = 0.79), and frictional force (r = 0.66). Moreover, a shorter dilator tip (r = 0.52), lower flexibility ratio (r = 0.52), and lower frictional force (r = 0.50) were correlated with a lower insertion force at the proximal ureter.

CONCLUSION

A UAS with a rigid base and flexible tip parts, a smoother surface, and a shorter dilator tip would be preferable for reducing the insertion force. These findings may be crucial for selecting or developing an ideal UAS that can decrease the risk of ureteral injury.

Controversies associated with ureteral access sheath placement during ureteroscopy

The use of ureteral access sheaths (UAS) is common practice during routine flexible ureteroscopy procedures. However, debates and concerns continue amongst endourologists on routine UAS placement. UAS placement allows for multiple passages of the ureteroscope, decreases intrarenal pressure, and may improve stone-free rates. However, concerns for the UAS's effectiveness in these claimed benefits and complications related to UAS placement has been documented and investigated by many. In this review, we will discuss the controversies surrounding the placement of UAS during ureteroscopy.

Intraoperative and postoperative surgical complications after ureteroscopy, retrograde intrarenal surgery, and percutaneous nephrolithotomy: a systematic review

INTRODUCTION

Retrograde ureteroscopy (URS), intra-renal surgery (RIRS) and percutaneous nephrolithotomy (PCNL) represent routine interventions for the treatment of ureteral and renal stones, although at times associated with serious adverse events. Of note, the evidence on perioperative complications after these procedures remains sparse and controversial. Moreover, there is a lack of standardized reporting of adverse events using uniform systems. The aim of the present study was to systematically review of the available evidence on URS/RIRS and PCNL for the surgical treatment of urinary stone, assessing the incidence of intra- and postoperative events, classified according to the modified Clavien-Dindo scale.

EVIDENCE ACQUISITION

A systematic review of the literature was performed according to PRISMA recommendations and was conducted on intra- and postoperative complications, as well as on their management, following URS, RIRS and PCNL procedures, particularly focusing on major events.

EVIDENCE SYNTHESIS

Overall, 26 studies (13 on URS/RIRS and 11 on PCNL) met the inclusion criteria and were evaluated. The highest intraoperative complication rate was 11.5% and 8.5% for RIRS and PCNL, respectively. Major complication rate following URS/RIRS and PCNL ranged between 0.3-31.7% and 2-17.1%, respectively. The most frequent adverse events were obstructive pyelonephritis or urinary leakage requiring the placement of a double J stent or a drainage. Among PCNLs series, life-threatening adverse events have also been reported, including bleeding requiring renal angioembolization and urothorax.

CONCLUSIONS

Despite the inclusion of series using a standardized reporting system, the complication rate after URS/RIRS/PCNL remains extensively heterogeneous in the literature; in addition, a non-negligible proportion of studies did not characterize the adverse events nor report the actual management strategy to solve them. Future research is needed to standardize the classification and reporting of surgical complications after endourological procedures (taking into consideration the surgeon's experience and skills), aiming to improve patient counseling and potentially the strategy for their prevention.

The effect of preoperative ureteral stenting in retrograde Intrarenal surgery: a multicenter, propensity score-matched study

Background

Stent placement before retrograde intrarenal surgery (RIRS) can theoretically expand the ureter to improve access and remove stones. The purpose of this study was to investigate the effect of preoperative ureteral stenting on access and surgery.

Methods

We retrospectively analyzed patients who underwent RIRS between January 2010 and December 2016 at multiple centers. The patients were divided into two groups based on whether or not a ureteral stent was inserted preoperatively. The characteristics of the stone (size, number, density, and location), the success rate of the access sheath placement, perioperative complications, operative times, hospitalization periods, the period for which the stents remained, postoperative urinary tract infection rates, stone-free rates, and additional treatment rates were analyzed.

Results

Overall, 727 patients were included in the study (113 were pre-stented and 614 were non-stented). The median stone size was 12.2 mm. The overall stone-free rate (SFR) was 85.8% for the pre-stented group and 83.2% for the non-stented group, showing no significant (p = 0.498) difference between the two groups. Preoperative ureteral stenting improved the success rate of sheath placement (93.8% vs. 85.3%, p = 0.023) during surgery. The access sheath size in participants in the pre-stented group showed a tendency to be larger than that in participants in the non-stented group. However, there were no differences in perioperative complications, operative times, additional treatment rates, and stone-free rates.

Conclusions

Although preoperative ureteral stenting did not affect operative outcomes, it increased the success rate of access sheath placement. Depending on the patient’s characteristics, preoperative ureteral stenting can be considered as an adjunctive option when access sheath insertion is considered during RIRS.

Management of Migrated or Residual Stones Following Laparoscopic Pyelolithotomy and Ureterolithotomy in Abnormal Kidneys: A Prospective and Randomized Comparison

Objective: To conduct a prospective and randomized controlled trial comparing contemporaneous transabdominal rigid ureteroscopy (TRU) with postoperative extracorporeal shockwave lithotripsy (SWL) in the management of migrated or residual stones during laparoscopic pyelolithotomy and ureterolithotomy in kidneys with either intrinsic or extrinsic abnormalities. Materials and Methods: From February 2016 to December 2019, 45 patients with migrated or residual stones following laparoscopic pyelolithotomy and ureterolithotomy were accrued and randomly divided into two groups. These patients all had either urinary tract obstruction distal to the stone or concomitant ipsilateral intrinsic or extrinsic pathology requiring laparoscopic intervention. Twenty-three patients underwent contemporaneous TRU, and 22 patients underwent postoperative SWL. Patients' demographics, perioperative variables, and follow-up data were collected. The primary outcome was the final stone-free rate (SFR) at the 2-month follow-up. Secondary outcomes included blood loss, operative time, change in serum creatinine, complications per Clavien-Dindo grading system, renal colic occurrence rate (RCOR), and postoperative hospitalization. Results: There was no significant difference in gender, age, body mass index, location, or stone burden between the two groups (p > 0.05). At the 2-month follow-ups, the SFR was higher in the TRU than the SWL group (p = 0.002), and the RCOR was lower in the TRU than the SWL group (p = 0.005). Postoperative hospitalization was also shorter for the TRU group. No significant difference was noted in the operative time, blood loss, change in serum creatinine, or perioperative complications (p > 0.05). Conclusion: Contemporaneous TRU is more effective and equally safe compared to postoperative SWL in the management of residual or migrated stones during laparoscopic pyelolithotomy and ureterolithotomy in kidneys with either intrinsic or extrinsic abnormalities.

The role of preoperative ureteral stenting in retrograde intrarenal surgery in renal stone patients: a propensity score-matched study

Background

The purpose of this study was to investigate the effect of preoperative ureteral stenting on retrograde intrarenal surgery (RIRS).

Methods

We retrospectively analyzed RIRS cases from October 2014 to June 2017. Patients were divided into two groups according to preoperative ureteral stent insertion. The characteristics of the patients [age, body mass index (BMI), sex, previous disease history, hemoglobin, creatinine, estimated glomerular filtration rate (eGFR)], characters of stone (size, number, density, location), ureteral access sheath (UAS) success rate, perioperative complication, operative time, hospitalization time, period with stent, postoperative urinary tract infection (UTI) rate, stone free rate (SFR), and additional treatment rate were analyzed.

Results

RIRS was performed for 122 patients. Seventy-three patients had preoperative ureteral stents before RIRS, while 49 patients did not have preoperative ureteral stents. The median size of the stone was 14.5 mm. Overall SFR was 87.7%. Preoperative eGFR was relatively high in patients who underwent preoperative stenting (68.18 vs. 79.01 mL/min/1.73 m², P=0.042). Preoperative stenting led to improvement in the success rate of UAS insertion (97.3% vs. 87.8%, P=0.038) during surgery. Before and after propensity score matching revealed a significant difference in operation time when the diameter of the stone was smaller than 1 cm (P=0.019 and P=0.004). However, there was no significant difference in operation time, postoperative UTI rate, additional treatment rate, or SFR.

Conclusions

Preoperative ureteral stenting can facilitate UAS insertion, and reduce operation time in RIRS for stones with a diameter less than 1 cm.

A retrospective study comparing super-mini percutaneous nephrolithotomy and flexible ureteroscopy for the treatment of 20-30 mm renal stones in obese patients

Objective

This study aimed to compare the efficacy and safety of Super-mini percutaneous nephrolithotomy (SMP) and flexible ureteroscopy (F-URS) in the treatment of 20–30 mm renal stones in obese patients.

Methods

We conducted a retrospective analysis of outcomes of patients who underwent SMP and F-URS to treat 20–30 mm renal stones from August 2017 to September 2018. Patients with BMI >30 kg/m² were enrolled into this study. Forty-eight patients underwent SMP, while 104 patients underwent F-URS by the same surgeon. The patients’ demographic data, stone characteristics, perioperative parameters and outcomes, complications, stone-free rate (SFR) and overall costs were retrospectively assessed.

Results

No significant differences were found between the two groups in terms of age, gender, BMI, operation side, stone size, number, locations, stone compositions and CT value. The mean operation time was significantly shorter in the SMP group (p < 0.001), while the F-URS group had significantly shorter postoperative stays (p < 0.001) and lower complication rates (p < 0.001). Both groups had similar SFR at a 3-month follow-up (p = 0.190), while the SMP group achieved significant higher SFR 3 days after the operation (p < 0.001). The SMP group had a significantly lower overall cost and fewer stage-2 procedures than the F-URS group.

Conclusion

SMP and F-URS are equally effective in obese patients with 20–30 mm renal stones. However, F-URS offers the advantage of a lower complication rate, while SMP performed better in terms of operation time, tubeless rate, stage-2 procedures and overall costs.

The effect of using ureteral access sheath for treatment of impacted ureteral stones at mid-upper part with flexible ureterorenoscopy: a randomized prospective study

BACKGROUND

The number of the studies made on the efficacy of flexible ureteroscopy (FURS) with ureteral access sheath (UAS) for impacted ureteral stones is limited. The aim of our study was to compare the efficacy and reliability of FURS in treatment of mid-upper impacted ureteral stones in cases where access is used or not.

METHODS

Between January 2017 and June 2018, 131 adult patients who applied to our clinic with complaints of mid-upper impacted ureteral stones. Patients were randomized as group 1 (without UAS) and group 2 (with UAS) by means of a draw and assessed in terms of demographic features, stone size, stone localization, hydronephrosis grade, operation time, scope time, the need for additional surgery, hospitalization time and complications.

RESULTS

The mean age of the patients in group 1 was 45.01 years (19-76) and was 37.01 years (16-80) in group 2. Mean stone size was 9.04 mm2 and 9.77 mm2 in group 1 and 2, respectively. Additional treatment was required for 26 (42.6%) patients in group 1 and 8 (11.4%) in group 2. No major intraoperative and postoperative complications developed in both groups. Although bleeding as a postoperative complication rate was similar, fever (>38° C) and urinary tract infection were higher in group 1 than in group 2.

CONCLUSIONS

In the treatment of mid-upper impacted ureteral stones, using UAS during the application of FURS is an advantageous procedure due to shorter operation time, fever intraoperative stone migrations and the need for additional surgery, less postoperative infection.

Dusting versus fragmentation for renal stones during flexible ureteroscopy

Objectives: To compare stone dusting and spontaneous passage vs fragmentation and active fragment retrieval during flexible ureteroscopy (fURS) for renal calculi.

Patients and methods: The study included patients who underwent fURS and holmium laser lithotripsy for renal calculi from January 2015 to March 2017. Dusting was done using low energy and high frequency (0.3–0.5 J and 15–20 Hz, respectively), and fragmentation was done with higher energy and lower frequency (1–1.2 J and 6–10 Hz, respectively) and then stone fragments were extracted using a basket. The stone-free rate (SFR) was evaluated after 2 months with non-contrast computed tomography. Operative time, complication rate, SFR, and the need for secondary procedures were compared.

Results: The study included 107 consecutive patients, with a mean (SD) age of 49 (13) years. Dusting was performed in 51 patients and fragmentation in 56. The patients’ demographics, laboratory tests, preoperative stents, stone and renal characteristics were comparable for both groups. Operative time was significantly shorter for dusting than fragmentation (76 vs 91 min, P = 0.009). Complication rates were comparable between the groups (7.8% for dusting and 8.9% for fragmentation, P = 0.840). The mean hospital stay was comparable for both groups (P = 0.686). The SFR was significantly better in fragmentation group (78.6%) compared with the dusting group (58.6%, P = 0.035). The need for a secondary procedure was 33.3% in the dusting group and 23.3% in fragmentation group (P = 0.244).

Conclusions: During fURS for renal stones, the dusting technique had a significantly shorter operation time, whilst the fragmentation technique led to a significantly better SFR. Both techniques have comparable safety, hospital stay, and requirement for secondary procedures.

Abbreviations: fURS: flexible ureteroscopy/ureteroscope; ICU: intensive care unit; KUB: plain abdominal radiograph of the kidney, ureter and bladder; NCCT: non-contrast CT; SFR: stone-free rate; SWL: shockwave lithotripsy; UAS: ureteric access sheath

Systematic review of ureteral access sheaths: facts and myths

The aim of the present paper was to review the literature on all available ureteral access sheaths (UASs) with their indications, limitations, risks, advantages and disadvantages in current modern endourological practice. Two authors searched Medline, Scopus, Embase and Web of Science databases to identify studies on UASs published in English. No time period restriction was applied. All original articles reporting outcomes or innovations were included. Additional articles identified through references lists were also included. Case reports, editorials, letters, review articles and meeting abstracts were excluded. A total of 754 abstracts were screened, 176 original articles were assessed for eligibility and 83 articles were included in the review. Based on a low level of evidence, UASs increase irrigation flow during flexible ureteroscopy and decrease intrapelvic pressure and probably infectious complications. Data were controversial and sparse on the impact of UASs on multiple reinsertions and withdrawals of a ureteroscope, stone-free rates, ureteroscope protection or damage, postoperative pain, risk of ureteral strictures, and also on its cost-effectiveness. Studies on the benefit of UASs in paediatrics and in patients with a coagulopathy were inconclusive. In the absence of good randomized data, the true impact of UASs on surgery outcome remains unclear. The present review may contribute to the evidence-based decision-making process at the individual patient level regarding whether or not a UAS should be used.

The application of a single-use fiberoptic flexible ureteroscope for the management of upper urinary calculi

OBJECTIVE

To evaluate the clinical outcomes with a Chinese single-use fiberoptic flexible ureteroscope (YouCare Tech) from a prospective database.

MATERIALS AND METHODS

A prospective study was conducted in a single center in China between January 2016 and October 2017. All consecutive patients who underwent flexible ureteroscopy performed by YouCare flexible ureteroscope were analyzed. Patients' demographics, clinical characteristics, intraoperative parameters, postoperative complications, and stone-free rate were evaluated and recorded. Stone-free status was defined as no visible stones or clinically insignificant residual stones < 2 mm on a postoperative image study.

RESULTS

A total of 684 procedures were performed for 653 patients (31 patients had bilateral stones). A double J stent had been previously placed in 431 patients. The location of the calculi was upper calyx, middle calyx, lower calyx, and renal pelvis and proximal ureter in 74, 101, 211, 115, and 183 patients, respectively. The median operative time was 52 min. The postoperative stone-free rate for the first 2 weeks after surgery was 78.5%, which increased to 91.1% at the first month. The overall stone-free rate was 95.2%. The complication rate was minor and short-term, such as gross hematuria or flank pain.

CONCLUSION

YouCare flexible ureteroscope can be considered effective and safe in the treatment of both upper ureteral and renal stones in selected patients. Further evaluation of comparison with other FURS's surgical outcomes and cost-effectiveness analysis will help to present the best utility of this single-use FURS in clinical practice.

Bilateral same-session flexible ureterorenoscopy for renal and/or ureteric stone disease treatment

Objective

To evaluate the effectiveness and safety of bilateral same-session flexible ureterorenoscopy (f-URS) in the treatment of bilateral renal and/or ureteric stone disease.

Patients and methods

From October 2007 to December 2015, 62 patients who had undergone bilateral, same-session f-URS were included in the study. The procedures were performed under general anaesthesia, in lithotomy, and initiated on the side in which the patient was clinically symptomatic or on the side in which the stone was smaller. Plain abdominal radiography, intravenous urography, renal ultrasonography and/or non-contrast computed tomography scans were conducted in all patients. The success rate was defined as, patients who were stone-free or only had residual fragments of <3 mm.

Results

A total of 62 patients (43 male, 19 female), with a mean (SD) age of 39 (15.1) years, were included. The mean (SD) stone size was 23.2 (6.11) mm with a mean (SD) operative time of 58.8 (16.24) min. The stone-free rates were 90.3% and 100% after the first and second procedures, respectively. The mean (SD) hospital stay was 1.58 (0.72) days. There were minor complications (Clavien–Dindo grade I–II) in 10 (16%) patients and major complications (Clavien–Dindo III–IV), e.g. distal ureter laceration and laser injury of the ureter, in two patients.

Conclusion

Same session bilateral f-URS is a successful and safe method for bilateral renal and/or ureteric stones.

Efficacy analysis of self-help position therapy after holmium laser lithotripsy via flexible ureteroscopy

BACKGROUND

To observe the efficacy of self-help position therapy (SHPT) after holmium laser lithotripsy via flexible ureteroscopy (FURS).

METHODS

From January 2010 to November 2015, 736 nephrolithiasis patients who had received FURS lithotripsy were analyzed retrospectively. In position group, 220 cases accepted SHPT after lithotripsies, and 428 cases as control, coming from another independent inpatient area in the same center. The stone-free status (SFS) between two groups were compared at the 2nd, 4th and 12th week ends by X-ray examinations.

RESULTS

The preoperative incidence of hydronephrosis (25.9% vs. 18.0%, p = 0.018) or lower calyceal seeper (33.6% vs. 24.3%, p = 0.012) and the proportion of patients with > 2.0 cm stones (33.6% vs. 24.3%, p = 0.003) were all significantly higher in position group than in control group. There were no substantial difference between two groups in age, BMI, gender and medical histories. In postoperative followup, the incidence of hydronephrosis in position group was significantly lower than in control group (9.5% vs. 15.7%, p = 0.032) after removing double-J stents. In position group, the SFS of the 2nd week end (60.9% vs. 47.2%, p = 0.001), the 4th week end (74.1% vs. 62.8%, p = 0.004) and the 12th week end (86.9% vs. 79.4%, p = 0.021) were all significantly higher than those in control group.

CONCLUSIONS

SHPT after holmium laser lithotripsy via FURS may increase postoperative SFS, accelerate stone fragment clearance, and decrease the incidence of hydronephrosis after removal of double-J stents. The therapy does not require professional assistance and is economical, simple, and effective.

"Valve"-Type Retainment of Flexible Ureteroscope in the Distal Ureter

Introduction: Flexible ureteroscopy (fURS) is an endoscopic procedure for the minimally invasive treatment of ureteral and renal calculi. Due to improvements in technique and ureteroscopic instrumentation over the past two decades, complications associated with URS are infrequent. However, in the event of an unexpected device malfunction or failure, the operating surgeon must employ prompt, resolute decision-making to resolve any intraoperative complications and avoid significant injury to the kidney or ureter. Case Presentation: The patient was a 53-year-old male with a 7 mm left upper pole renal stone managed by fURS and laser lithotripsy. A ureteral access sheath (UAS) was not deployed during the procedure. During fragmentation of the stone, we were unexpectedly unable to retract the ureteroscope from the ureter. Herein, we describe the procedural details leading up to the complication and the careful maneuvering required to remove the ureteroscope without damaging the ureter or the instrument. Conclusions: We recommend use of a UAS during fURS for the treatment of ureteral and renal calculi, if not using ureter access sheath, not advancing the ureteroscope above the stone, leaving it behind the tip of the instrument, while in the ureter. Utilization of a ureter access sheath could have possibly avoided this kind of complication.

Is There A Difference Between Presence of Single Stone And Multiple Stones in Flexible Ureterorenoscopy And Laser Lithotripsy For Renal Stone Burden < 300mm2 ?

In this study, we aim to evaluate and compare the effectiveness of flexible ureterorenoscopy (f-URS) for solitary and multiple renal stones with < 300 mm2 stone burden. Patients' charts who treated with f-URS for kidney stone between January 2010 and June 2015 were reviewed, retrospectively. Patients with solitary kidney stones (n:111) were enrolled in group 1. We selected 111 patients with multiple kidney stones to serve as the control group and the patients were matched at a 1:1 ratio with respect to the patient's age, gender, body mass index and stone burden. Additionally, patients with multiple stones were divided into two groups according to the presence or abscence of lower pole stones. Stone free status was accepted as complete stone clearence and presence of residual fragments < 2 mm. According to the study design; age, stone burden, body mass index were comparable between groups. The mean operation time was longer in group 2 (p= 0.229). However, the mean fluoroscopy screening time in group 1 and in group 2 was 2.1±1.7 and 2.6±1.5 min, respectively and significantly longer in patients with multiple renal stones (P=0.043). The stone-free status was significantly higher in patients with solitary renal stones after a single session procedure (p=0.02). After third month follow up, overall success rate was 92.7% in Group 1 and 86.4% in Group 2. Our study revealed that F-URS achieved better stone free status in solitary renal stones < 300 mm2. However, outcomes of F-URS were acceptable in patients with multiple stones.

Histopathological correlations to ureteral lesions visualized during ureteroscopy

Purpose

To correlate ureteral lesions visualized during ureteroscopy with histopathological findings.

Materials and methods

Ureteral access sheaths (UAS) sized 13/15 Fr. were inserted bilaterally in 22 laboratory pigs. During retraction of the UAS with a semirigid ureteroscope inside, ureteral lesions were evaluated and registered using the Post-ureteroscopic lesion scale (PULS). Ureters were excised in vivo between the uretero–pelvic junction and the uretero–vesical junction. Embedded in paraffin, 4-µm thick sections were step sectioned at 250–300 µm intervals and haematoxylin and eosin (HE) stained. Histopathological scoring of ureteral wall lesions was subsequently performed according to PULS.

Results

In 72.1% of ureters, the highest histopathological score was at least 1 grade higher than the highest endoscopic PULS score. For 12 (27.9%) lesions, the difference was 2 scores higher, and for 1 (2.3%), it was 3 scores higher. The histopathological PULS grade was higher than the endoscopical PULS grade at all minimum, quartile, and maximum scores. There was a significant difference in the distribution of highest lesional scores between the endoscopic and histopathological PULS (p = 0.002). The calculated mean of the highest scores was 1.49 for endoscopic PULS and 2.51 for histopathological PULS (p < 0.0001).

Conclusion

Histopathological evaluation of ureteral wall lesions after UAS placement revealed a significantly higher degree of severity than observed endoscopically. Thus, endoscopy underestimated the histopathological extent of the lesion in the majority of cases.

Is a ureteral stent required after use of ureteral access sheath in presented patients who undergo flexible ureteroscopy?

Introduction

Use of a ureteral access sheath (UAS) within flexible ureteroscopy (fURS) for the management of kidney and ureteral stones has shown improvements in its effectiveness, but it is also associated with increased risk of ureteral injury. Use of ureteral stent (US) after fURS is recommended by some authors, because of its role in reducing postoperative pain and preventing complications. Our objective is to determine if postoperative stenting is necessary in pre-stented patients that underwent fURS using UAS.

Material and methods

A retrospective history review of patients who underwent fURS using UAS at our hospital between July 1^st 2013 and May 31^st 2016 was performed. Only pre-stented patients were included. All procedures were performed using the same UAS (Boston Navigator TM., 11–13 Fr.). Patients were separated according to the use or not of postoperative US. The same US (26 cm 6 Fr percuflex, Boston Scienfic) was used for all stented patients. Clinical parameters, stone demographics, operative time and postoperative events were analyzed.

Results

Seventy patients met the inclusion criteria. Mean stone size was 8.5 mm (SD 7.06), 68.49% were located in the renal pelvis and 31.51% were in the proximal ureter. Reasons of preoperative stenting were: 14 (19.18%) ureteral stricture, 17 (23.29%) urosepsis, 29 (39.73%) residual stones after a first intervention (stage procedure) and 13 (17.8%) unsuccessful extracorporeal shockwave lithotripsy. Mean operative time was 88 minutes (SD 37.20); 32 patients (45.71%) were stented and 38 (54.28%) were not. There were no significant differences in operative time (p = 0.85) or postoperative outcomes (p = 1).

Conclusions

A postoperative ureteral stent is not necessary after fURS using UAS in pre-stented patients.

Flexible ureteroscopy for renal stone without preoperative ureteral stenting shows good prognosis

Purpose

To clarify the outcome of flexible ureteroscopy (fURS) for management of renal calculi without preoperative stenting.

Methods

A total of 171 patients who received 176 fURS procedures for unilateral renal stones were reviewed. All procedures were divided into two groups depending on whether they received ureteral stenting preoperatively. Baseline characteristics of patients, stone burden, operation time, stone-free rates, and complications were compared between both groups.

Results

Successful primary access to the renal pelvis was achieved in 104 of 114 (91.2%) patients without preoperative stenting, while all procedures with preoperative stenting (n = 62) were successfully performed. A total of 156 procedures were included for further data analysis (56 procedures in stenting group and 100 in non-stenting group). No significant differences was found regardless of a preoperative stent placement in terms of stone-free rate (73.2% with stenting vs. 71.0% without, P = 0.854), operative time (70.4 ± 32.8 with stenting vs. 70.2 ± 32.1 without, P = 0.969).

Conclusions

fURS for management of renal stone without preoperative ureteral stenting are associated with well outcome in short term follow-up. Our study may help patients and doctors to decide if an optional stent is placed or not.

Novel Biocompatible Adhesive for Intrarenal Embedding and Endoscopic Removal of Small Residual Fragments after Minimally Invasive Stone Treatment in an Ex Vivo Porcine Kidney Model: Initial Evaluation of a Prototype

PURPOSE

Residual fragments related to endoscopic intracorporeal lithotripsy are a challenging problem. The impact of residual fragments remains a subject of discussion and growing evidence highlights that they have a central role in recurrent stone formation. Therefore, we developed a novel bioadhesive system for intrarenal embedding and retrieval of residual fragments after endoscopic lithotripsy in an ex vivo porcine kidney model.

MATERIALS AND METHODS

In a standardized setting 30 human stone fragments 1 mm or less were inserted in the lower pole of an ex vivo porcine kidney model. We assessed the extraction efficacy of flexible ureteroscopy using the bioadhesive system in 15 preparations and a conventional retrieval basket in 15. Outcomes were compared regarding the endoscopic and macroscopic stone-free rate, and overall time of retrieval.

RESULTS

Embedding and retrieving the residual fragment-bioadhesive complex were feasible in all trial runs. We observed no adverse effects such as adhesions between the adhesive and the renal collecting system or the instruments used. The stone-free rate was 100% and 60% in the bioadhesive and conventional retrieval groups, respectively (p = 0.017). Mean retrieval time was significantly shorter at 10 minutes 33 seconds vs 36 minutes 56 seconds in the bioadhesive group vs the conventional group (p = 0.001).

CONCLUSIONS

This novel method involving adhesive based complete removal of residual fragments from the collecting system has proved to be feasible. Our evaluation in a porcine kidney model revealed that this technology performed well. Further tests, including inpatient studies, are required to thoroughly evaluate the benefit and potential drawbacks of bioadhesive based extraction of residual fragments after intracorporeal lithotripsy.

Outcomes of flexible ureteroscopy and laser fragmentation for treatment of large renal stones with and without the use of ureteral access sheaths: Results from a university hospital with a review of literature

OBJECTIVE

The aim of this study was to analyse prospective data on flexible ureteroscopy and laser fragmentation (FURSL) of large stones (> 2 cm) to assess whether a ureteral access sheath (UAS) is necessary for the treatment of large renal stones.

MATERIALS AND METHODS

Between March 2012 and October 2014, 43 patients with large stones underwent FURSL. Data were collected on a prospective database for patient demographics, stone characteristics and outcomes of FURSL with and without a UAS.

RESULTS

There were 27 men and 16 women with a mean age of 54 years (range 7-84 years). The cumulative stone diameter was 2.92 cm (range 2-5 cm), with an overall stone-free rate (SFR) of 83.7%. A total of 68 procedures was needed (average 1.58 procedures/patient). The overall complication rate was 8.8% (n = 6); these were Clavien class II complications associated with urinary tract infections treated with additional antibiotics. UAS was not used in 28 procedures (41.2%). Comparing outcomes in those who had a UAS versus those who did not, there were no statistical differences in SFR, complication rate or average number of procedures per patients.

CONCLUSION

Use of a UAS does not make any difference to the SFR or complication rate for FURSL in large stones (> 2 cm) and may not be routinely needed in all cases.

Use of ureteral access sheaths in ureteroscopy

The ureteral access sheath (UAS) facilitates the use of flexible ureteroscopy, enabling improved minimally invasive management of complex upper urinary tract diseases. The UAS, which comes in a variety of diameters and lengths, is passed in a retrograde fashion, aided by a hydrophilic coating and other features designed to confer smooth passage into the ureter with sufficient resistance to kinking and buckling. Use of a UAS has the advantage of enabling repeated passage of the ureteroscope while minimizing damage to the ureter, thus improving the flow of irrigation fluid and visualization within the urethra with reductions in operative times, which improves both the effectiveness of the surgery and reduces the costs. Placement of the UAS carries an increased risk of ureteral wall ischaemia and injury to the mucosal or muscular layers of the ureter, and a theoretically increased risk of ureteral strictures. A ureteral stent is typically placed after ureteroscopy with a UAS. Endourologists have found several additional practical uses of a UAS, such as the percutaneous treatment of patients with ureteral stones, and solutions to other endourological challenges.

Urolithiasis in pregnancy: a cost-effectiveness analysis of ureteroscopic management vs ureteral stenting

OBJECTIVE

The purpose of this study was to determine the cost-effectiveness of serial stenting vs ureteroscopy for treatment of urolithiasis during pregnancy as a function of gestational age (GA) at diagnosis.

STUDY DESIGN

We built decision analytic models for a hypothetical cohort of pregnant women who had received a diagnosis of symptomatic ureteral calculi and compared serial stenting to ureteroscopy. We assumed ureteral stent replacement every 4 weeks during pregnancy, intravenous sedation for stent placement, and spinal anesthetic for ureteroscopy. Outcomes were derived from the literature and included stent infection, migration, spontaneous kidney stone passage, ureteral injury, failed ureteroscopy, postoperative urinary tract infection, sepsis, and anesthetic complications. Four separate analyses were run based on the GA at diagnosis of urolithiasis. Using direct costs and quality-adjusted life years, we reported the incremental costs and effectiveness of each strategy based on GA at kidney stone diagnosis and calculated the net monetary benefit. We performed 1-way and Monte-Carlo sensitivity analyses to assess the strength of the model.

RESULTS

Ureteroscopy was less costly and more effective for urolithiasis, irrespective of GA at diagnosis. The incremental cost of ureteroscopy increased from -$74,469 to -$7631, and the incremental effectiveness decreased from 0.49 to 0.05 quality-adjusted life years for a kidney stone diagnosed at 12 and 36 weeks of gestation, respectively. The net monetary benefit of ureteroscopy progressively decreased for kidney stones that were diagnosed later in pregnancy. The model was robust to all variables.

CONCLUSION

Ureteroscopy is less costly and more effective relative to serial stenting for urolithiasis, regardless of the GA at diagnosis. Ureteroscopy is most beneficial for women who received the diagnosis early during pregnancy.

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.

Predicting an effective ureteral access sheath insertion: a bicenter prospective study

INTRODUCTION

The use of a ureteral access sheath (UAS) may provide significant advantages, particularly, in the treatment of a large renal stone burden. However, in some patients, the passage of a UAS up the ureter is impossible. We prospectively evaluated the ability to insert a 14F UAS and analyzed the possible predictors for an effective insertion.

PATIENTS AND METHODS

In a bicenter prospective study, 248 consecutive patients undergoing ureteroscopy and retrograde intrarenal surgery (RIRS) were recruited. In each case, we attempted initially to pass a 14F Flexor-Cook UAS. If passage was difficult, gradual dilation using semirigid ureteral dilators (Cook Medical) was performed. Patients were categorized into three groups: effective passage, with and without dilation, and failure to pass the UAS. Age, gender, body-mass index (BMI), an indwelling Double-J stent, and a history of previous ureteroscopy or Double-J stent were all analyzed, as possible predictors for an effective UAS insertion.

RESULTS

In 22% of the patients, we could not pass a 14F UAS. Of the preoperative parameters that were examined, we found three independent predictors for an effective 14F UAS insertion: age (odds ratio: 1.5 and 95% CI [1.3, 1.9]), previous same-side procedures (odds ratio: 9.7 and 95% CI [8.3, 14.5]), and an indwelling Double-J stent (odds ratio: 21.73 and 95% CI [20, 30]). The gender, BMI, and side of surgery did not predict the success rate.

CONCLUSIONS

Insertion of a 14F UAS before RIRS may fail in approximately one-fifth of the patients. An indwelling Double-J stent, a history of previous ureteroscopy or Double-J stent, and older age are all significant predictors for an effective 14F UAS insertion.

Retrograde intrarenal surgery with holmium-YAG laser lithotripsy in the primary treatment of renal lithiasis

INTRODUCTION

retrograde intrarenal surgery (RIRS) appears as a safe and effective technique as well as a good therapeutic alternative to extracorporeal shock wave lithotripsy (ESWL) and percutaneous nephrolithotomy (PNL).

MATERIAL AND METHODS

descriptive study in 50 patients surgically treated between November 2012 and April 2013. Demographic, operative and postoperative data as well as early and late complications data were collected. The minimum follow-up of patients was one year. Surgery was performed under general anesthesia. Flexible ureteroscopy with ureteral access sheath and laser fragmentation were employed. Surgery success was defined as stone free rate in postoperative control test and at three months after surgery (simple radiography, abdominal ultrasound or CT without contrast).

RESULTS

mean age was 51.1±15.5 years old. The highest-frequency location was the lower calyceal group (26%), single stones were described in 58% of patients whilst multiple lithiasis were found in the 42%. Regarding the stone burden in 44% of the patients was low (<2 cm), and high (>3 cm) in 22% of the patients. The stone clearance rate was 89.7±17.5. Average surgery time was 96.6±35.2min. Complications were reported in 4 patients (8%), all of them early ones and minor in nature.

CONCLUSIONS

RIRS is an effective and safe option whose results are comparable to ESWL and PCNL. RIRS can be considered as first-line treatment. These results are corroborated by numerous studies. To strengthen these findings, prospective studies focusing on quality of life, length of stay, complications and cost-effectiveness of different treatments are needed.

Ultra-mini PCNL versus flexible ureteroscopy: a matched analysis of analgesic consumption and treatment-related patient satisfaction in patients with renal stones 10-35 mm

PURPOSE

To compare ultra-mini PCNL (UMP) and flexible ureteroscopy (fURS) for the treatment of medium- to large-sized renal stones with a focus on patients' postsurgical cumulative analgesic consumption and treatment-related satisfaction.

METHODS

Twenty-five patients treated by UMP between April 2013 and October 2014 were matched to data of 25 fURS patients from an existing database. Clinical outcome parameters were recorded prospectively. Postoperative analgesic consumption was assessed using the Cumulative Analgesic Consumption Score (CACS), and satisfaction was measured with the Freiburg Index of Patient Satisfaction (FIPS) questionnaire.

RESULTS

Perioperative outcome parameters showed no significant differences except for mean operating times (fURS 98.52 min, UMP 130.12 min [p = 0.002]) and hospital stay (fURS 67.2 h, UMP 91.5 h [p = 0.04]). Primary stone-free rate was 96 % in fURS and 92 % in UMP. Complications Clavien grade 2 or 3 occurred in 16 % of UMP patients and in 4 % of fURS patients. Postsurgical cumulative analgesic consumption was almost identical in both groups with CACSs of 6.96 (0-15) for fURS and 6.8 (0-23) for UMP. Patients' satisfaction was high in both techniques: FIPS score in fURS 1.67 (1-3) and 1.73 (1-4) in UMP (scale 1-6).

CONCLUSIONS

Treatment of medium- to large-sized renal stones is safe and highly effective by both UMP and fURS. Moreover, both treatments yield comparable postsurgical analgesic requirements and high patient satisfaction scores. Patient-related factors (anatomical and stone related) and availability of technical equipment and surgical expertise appear to be the most important determining factors in treatment planning.

Effect of urinary stone disease and its treatment on renal function

Urolithiasis is a common disease that affects urinary tract in all age groups. Both in adults and in children, stone size, location, renal anatomy, and other factors, can influence the success of treatment modalities. Recently, there has been a great advancement in technology for minimally invasive management of urinary stones. The epoch of open treatment modalities has passed and currently there are much less invasive treatment approaches, such as percutaneous nephrolithotomy, ureteroscopy, shockwave lithotripsy, and retrograde internal Surgery. Furthermore, advancement in imaging technics ensures substantial knowledge that permit physician to decide the most convenient treatment method for the patient. Thus, effective and rapid treatment of urinary tract stones is substantial for the preservation of the renal function. In this review, the effects of the treatment options for urinary stones on renal function have been reviewed.

[Initial experience of first 225 flexible ureteroscopy with laser lithotripsy in a primary care hospital]

INTRODUCTION

During the last decade, the advent of flexible ureteroscopy with laser lithotripsy has revolutionized the management of upper urinary tract stones. Our center is a primary care hospital that is equipped with this technology since January 2011. This study reported our initial experience of first 225 cases.

MATERIEL AND METHODS

This study is a descriptive, retrospective and monocentric analysis. The first 225 cases, operated consecutively by 3 surgeons during 26 months, were analyzed. We have used 2 flexible ureteroscopes (1 digital, 1 optical). Laser source was an Holmium laser (Stonelight) at a power of 5 watts.

RESULTS

The mean age was 53 years (± 10.2) and the mean stones size was 11 mm (2.3). In 49% of cases, ureteroscopy was chosen for the first, without prior treatment. In 59% of cases, ureteroscopy was used after failure of other treatment (ESWL in 70% of cases). The mean operative time was 72 minutes (± 16.6) and the mean length of stay was 2.6 days (± 0.8). The first session of ureteroscopy was a success in 93% of cases without residual fragments after 1 month. The frequency of postoperative complications was estimated at 8% (Clavien I and II).

CONCLUSION

Flexible ureteroscopy with laser lithotripsy was a safe and effective technique, allowing the treatment of all upper urinary tract stones, especially on failure of other treatment. Its place in the first intention is widespread in our exercise, especially among obese patients, patients on anticoagulant therapy or with stone of the lower pole.

Flexible ureteroscopy with holmium laser lithotripsy: a new choice for intrarenal stone patients

OBJECTIVE

To evaluate the efficiency and safety of flexible ureteroscopy (FURS) and holmium lithotripsy for intrarenal stones and to stratify the efficiency and safety by stone burdens of ≤20, 20-40, and ≥40 mm.

METHODS

Five hundred eighty-two patients with intrarenal stones were treated with FURS and holmium lithotripsy at a single department from August 2008 to October 2013. Stone size was evaluated by calculating the cumulative stone diameter of all intrarenal stones, and stone-free status was defined as the absence of any stone or stone fragment <1 mm in the kidney.

RESULTS

Data analysis revealed a mean stone burden of 21.8 ± 7.6 mm. The overall primary stone-free rate (SFR) was 65.3%, which increased to 89.0% 6 months after the first surgery. Complications developed in 6.7% of patients. A significant difference was found between lower-calyx stones and other stones (p < 0.001; p = 0.006), while noncalcium stones had a much higher SFR than calcium stones (p < 0.001; p = 0.04).

CONCLUSION

Our study showed that the overall renal SFR with the use of FURS and holmium lithotripsy was satisfactory, with a relatively low complication rate. We believe that FURS with holmium lithotripsy could be a valuable choice for patients with renal stones, especially for patients with a cumulative stone burden ≤40 mm.

Is retrograde intrarenal surgery a viable treatment option for renal stones in patients with solitary kidney?

PURPOSE

To evaluate the effectiveness and safety of retrograde intrarenal surgery (RIRS) for stones up to 2 cm in diameter in patients with solitary kidney.

METHODS

From January 2008 to January 2013, we prospectively enrolled all consecutive patients with solitary kidney and renal stones. Plain abdominal computed tomography scan was performed preoperatively and 1 month after the procedure to assess the stone-free rates (SFR). Serum creatinine levels were detected preoperatively, at day 1 postoperatively, at 1 month postoperatively, and then every 6 months postoperatively.

RESULTS

During the study period, we prospectively enrolled a total of 29 patients. The mean age was 55.7 ± 12.3 years; the mean stone size was 1.3 ± 0.4 cm. The primary SFR was 72.4 %; the secondary SFR was 93.1 %. The mean number of procedures per patient was 1.24. The mean serum creatinine levels were 1.5 ± 0.6, 1.6 ± 0.7, 1.6 ± 0.6, and 1.7 ± 0.7 mg/dl preoperatively, at 1 day after RIRS, at 1 month after RIRS, and at 1 year after RIRS, respectively, without detection of any statistical difference (p = 0.76). Median follow-up time was 35.7 ± 19.3 (12-72) months, but that was available for only 18 patients. The mean serum creatinine level at the last follow-up was 1.7 ± 0.9 mg/dl. No major complications were recorded. Grade I complications occurred in eight patients (27.4 %).

CONCLUSIONS

RIRS is safe and effective in the treatment of renal stones in patients with solitary kidney, without worsening renal function.

Improved durability of flex-Xc digital flexible ureteroscope: how long can you expect it to last?

OBJECTIVE

To retrospectively analyze a significant number of flexible ureterorenoscopic procedures performed with the Storz Flex-Xc model to evaluate its durability.

MATERIALS AND METHODS

Between May 2012 and May 2013, all the flexible ureteroscopic procedures performed with 3 Storz Flex-Xc flexible ureteroscopes were analyzed. Relocation of the lower pole stones was performed in all cases when possible. In the second and third series, the access sheath was retracted together with the flexible ureteroscope, thus preventing the damages, which its distal part may inflict on the flexed endoscope.

RESULTS

A total of 406 procedures were performed on 372 patients: first endoscope used on 96 procedures (90 patients), second one on 151 procedures (139 patients), and third one on 159 procedures (143 patients). Ureteral access sheath was used in 71.4% of the cases. The first endoscope was used for 67.1 hours, the second for 107.7 hours, and the third one for 107.2 hours. Major repairs were needed after significant damages of the outer coating (first endoscope) and severe deterioration of the deflecting mechanism (second and third endoscopes).

CONCLUSION

The digital Storz Flex-Xc seems to be a durable model of flexible ureteroscope. The use of ureteral access sheath and avoidance of overstressing the deflection mechanism by relocating lower pole stones seem to offer substantial advantages in prolonging the lifespan of these expensive instruments.

A prospective comparative study between minimally invasive percutaneous nephrolithotomy in supine position and flexible ureteroscopy in the management of single large stone in the proximal ureter

OBJECTIVE

To investigate the difference and relative advantages between minimally invasive percutaneous nephrolithotomy (MPCNL) in supine position and flexible ureteroscopy (FURS) in the management of surgically indicated single large stone in the proximal ureter.

METHODS

Patients with single large stone in the proximal ureter with slight to moderate hydronephrosis were prospectively selected and assigned into groups of MPCNL and FURS on the basis of the patient's choice. Demographic data, operative duration, postoperative hospital stay, complication rate, and stone-free rate were recorded and compared.

RESULTS

From October 2010 to May 2012, 76 such patients were consecutively included into the study. No significant difference was found in preoperative demographics, including age, sex, and severity of hydronephrosis. Stone size was 15.6 ± 2.5 and 14.9 ± 2.3 mm (P = .349), operative duration 49.3 ± 11.7 and 67.2 ± 17.3 minutes (P <.001), postoperative hospital stay 4.2 ± 1.1 and 1.8 ± 0.8 days (P <.001), stone-free rate (residual ≤ 3 mm) 93.7% and 84.1% (P = .198), and complication rate over grade II (modified Clavien system) 12.5% and 6.8% (P = .398) in MPCNL and FURS groups respectively.

CONCLUSION

Both MPCNL in supine position and FURS are effective and safe surgical options for patients with single large stone in the proximal ureter, when indicated. FURS is associated with faster recovery and less invasiveness than MPCNL in supine position.

Concomitant treatment of ureteropelvic junction obstruction and renal calculi with robotic laparoscopic surgery and rigid nephroscopy

INTRODUCTION

The treatment of ureteropelvic junction obstruction (UPJO) and concomitant calculus poses a technically challenging situation. We present our experience with using rigid nephroscopy for renal calculi removal during robot-assisted pyeloplasy (RAP) for UPJO.

TECHNICAL CONSIDERATIONS

From December 2010 to November 2012, 25 patients with UPJO had RAP at our institution; 9 of those had concurrent renal calculi, which were simultaneously treated with rigid nephroscopy. For stone extraction, a rigid ureteroscope was passed through an assistant trocar under laparoscopic vision directly into a previously created pyelotomy. The stones were extracted using a rigid grasper or stone basket through the rigid ureteroscope. For the removal of the stones within the upper and lower calyces, the rigid ureteroscope was introduced into the incised renal pelvis through robotic trocars if the "assistant trocar" route failed. Complete stone clearance was achieved in 8 of 9 patients. Residual calculi in 1 patient were removed with a single session of extracorporeal shock wave lithotripsy. At the mean follow-up of 10.2 months, no patients had obstruction or recurrent stones. The mean operative time was 187.1 minutes, which was 40.9 minutes longer than the mean operative time in patients without renal calculi. There was no significant difference in blood loss, hospital stay, complications, and success rates between patients with and without renal calculi.

CONCLUSION

Our data suggest that the use of a concomitant rigid nephroscope and RAP is a safe and feasible option for the treatment of UPJO complicated with renal calculi.