Safety And Efficacy of Ureteral Access Sheaths

Sheathless RIRS in the era of slim and single use flexible ureteroscopy (ssFURS): Prospective analysis of clinical outcome

INTRODUCATION

the purpose is to assess the feasibility of sheathless and time-limited retrograde intrarenal surgery (RIRS) using slim and single use flexible ureteroscopy (ssFURS) in view of the stone-free rate (SFR), complication rate and upfront ureteral stenting.

METHODS

A prospective, cross-sectional study of patients who underwent RIRS for kidney stones between December 2021 and December 2023 at our tertiary urology center was performed. Patient demographics, clinical presentations and stone characteristics were calculated. The SFR and complication rate were included.

RESULTS

Hundred and eighteen patients were included. The median age was 48 (35.7-60.0) years. Diabetes mellitus (DM) was present in 32 patients (27.1%). The median length of the kidney stones was 1.15 (range [0.4-3.0]), and the median width was 1 (range [0.05-3.7]). The pelvi-ureteric junction (PUJ) represented 75 (63.6%) patients. The lower pole stone (LP) consisted of 27 (22.9%) patients. Thirty-seven (31.4%) of the patients had multiple kidney stones. An overall complete SFR after the first session was observed for 94 (79.7%) patients. The second session of complete SFR was observed in 15 patients (12.7%). A median stone length of 1 (0.8-1.5) cm and a median stone width of 0.95 (0.7-1.3) cm were both significantly associated with a complete SFR after the first session (p < 0.001). A single kidney stone in 69 (73.4%) patients was significantly more strongly associated with a complete SFR after the first session than was multiple kidney stones in 25 (26.6%) patients (p = 0.027). Upfront stenting was performed in 74 patients (62.7%). The complete SFR after the first session was significantly greater in patients who underwent upfront stenting (65; 69.1%) than in those who underwent primary ssFURS (29; 30.9%, p = 0.004).

CONCLUSION

Sheathless and time-limited RIRS using ssFURS is a feasible and successful procedure with low complication rate.

Peak Force of Insertion During Ureteral Access Sheath Placement In An Ex-Vivo Experimental Model With Different Commercially Available Access Sheaths

OBJECTIVE

To measure the force necessary to win the resistance during insertion of ureteral access sheaths (UAS) in an experimental homemade model and to compare the peak force of insertion (PFOI) of different commercially available UASs.

METHODS

Three investigators (2 novice and 1 expert) inserted the UASs into 2 different adapters with diameters of 10 Fr and 8 Fr. The force of insertion was continuously measured with a digital force gauge connected to the UAS during each insertion. Four different brands of UAS with different diameters, totally 11 different UASs were used for the experiment. The PFOI of each UAS was compared among each other and adapter diameters.

RESULTS

The mean PFOI in adapters 1 and 2 were 1.85 N and 5.32 N, respectively. All of the mean PFOIs were significantly lower in adapter 1 compared to adapter 2, regardless of the novice vs expert surgeons and the UASs. (P <.001) In adapter 1, the mean PFOI was lowest with the UAS-1 and highest with the UAS-8. In adapter 2, the mean PFOI was lowest with the UAS-3 and highest with the UAS-9. For adapters 1 and 2, no statistical difference was found when comparing an expert and the 2 novice surgeons.

CONCLUSION

The PFOI during UAS placement is not solely correlated with UAS thickness and adapter diameters. Other factors such as hydrophilic coating, UAS flexibility, inner dilator properties, UAS smoothness, and the actual measured external diameter of UASs should be taken into consideration. The clinical relevance and ureteral injury risk of the UAS PFOI need to be studied.

Endoscopic combined intrarenal surgery without ureteral access sheath performed for renal stone after Cohen reimplantation

Introduction

Endoscopic combined intrarenal surgery after anti-reflux operation is rarely performed.

Case presentation

A 37-year-old female was referred to our hospital for treatment of left renal stone. She underwent anti-reflux surgery (Cohen reimplantation) for left vesicoureteral reflux at the age of 10 years. Computed tomography revealed a 17 × 11 mm left inferior calyceal calculus. The patient received retrograde double-J stent insertion under radiographic guidance and underwent ultra-mini endoscopic combined intrarenal surgery without ureteral access sheath. The patient was discharged on postoperative Day 5 with no postoperative complications. Postoperative cystography showed no recurrence of vesicoureteral reflux. One month after the operation, kidney-ureter-bladder radiography and computed tomography scan revealed no residual stones or hydronephrosis.

Conclusion

Ultra-mini endoscopic combined intrarenal surgery without ureteral access sheath is an effective method for treating renal stones after Cohen reimplantation.

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.

The relationship between the force applied and perceived by the surgeon during ureteral access sheath placement: ex-vivo experimental model

PURPOSE

To define a peak force of insertion (PFOI) threshold for ureteral damage during ureteral access sheath (UAS) placement on an experimental ureteral orifice model.

METHODS

A specially designed water tank using 2 laparoscopic 5 mm ports and 2 different size (10 Fr and 8 Fr) sealing cap adaptors (SCA) as ureteral orifices was used to perform the test. A 10-12 Fr UAS was fixed to a load cell and the force of insertion (FOI) was continuously recorded with a digital force gauge.13 experts in the field of endourology who participated performed 3 UAS insertions. The FOI was recorded initially with 10 Fr followed by 8 Fr SCA. On the final insertion, the orifice was obstructed, leaving a 5 cm length to insert the UAS. The experts were asked to "Stop at the point they anticipate ureteral damage, and they would not proceed in real life".

RESULTS

Using 10 Fr SCA the PFOI was 2.12 ± 0.58 Newton (N) (range:1.48-3.48) while 8 Fr SCA showed a PFOI 5.76 ± 0.96 N (range:4.05-7.35). Six of the experts, said they would stop proceeding when they reached above 5.1 N. Three experts had PFOI < 5.1 N and the other 4 stated they would go with PFOIs of 5.88, 6.16, 6.69 and 7.35 N when using SCA of 8 Fr.The highest load they would stop proceeding had a PFOI of 6.09 ± 1.87 N (range: 2.53-10.74).

CONCLUSION

The PFOI threshold for ureteral damage inserting UAS of the experts is variable. Although FOI is a subjective perception, experience suggests that ureteral injury may occur at an average of 6.05 N perceived by surgeons' tactile feedback. In-vivo measurement of UAS PFOI may confirm a threshold.

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.

2022 Recommendations of the AFU Lithiasis Committee: Ureteroscopy and ureterorenoscopy

Technical advances, including miniaturization, have improved the deflection and optical performance of the ureteroscopes, and the availability of dedicated disposable devices have led to their increasing use for kidney and ureteral stone management. Ureterorenoscopy brings diagnostic evidence through the endoscopic description of stones and renal papillary abnormalities. Currently, intracorporeal lithotripsy during ureterorenoscopy is based on laser sources. Routine ureteral stenting is not necessary before ureterorenoscopy, especially because preoperative stenting for>30 days is considered as an independent risk factor of infection. Ureteral access sheaths allow the easy and repeated access to the upper urinary tract and thus facilitate ureterorenoscopy. Their use improves vision, decreases intrarenal pressure, and possibly reduces the operative time, but they may cause ureteral injury. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendation (CPR) method and the ADAPTE method, depending on whether or not the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis [EAU 2022]) and their adaptability to the French context.

Effect of bladder emptying status on the ureteral access sheath insertion resistance and following ureteral injury in RIRS: a prospective randomized controlled trial in academic hospital

PURPOSE

To evaluate the effect of bladder emptying status on the ureteral access sheath (UAS) insertion resistance and following ureteral injury.

METHODS

Eighty patients were enrolled and randomly divided into bladder emptying group and control group before UAS placement. A digital force gauge (Imada Z2-50N) was used to measure the resistance during the UAS insertion. The ureteral injury was evaluated and graded with Post-Ureteroscopic Lesion Scale (PULS) system at the end of procedure. The mean resistance, maximum resistance in different ureteral segments, and ureteral injury were compared between the two groups.

RESULTS

The mean resistance (3.12 ± 0.49 vs. 4.28 ± 0.52 N, P < 0.001), maximum resistance in the whole procedure (5.17 ± 0.72 vs. 6.39 ± 0.96 N, P < 0.001) and distal ureter (3.07 ± 0.75 vs. 6.18 ± 1.17 N, P < 0.001) in the bladder emptying group were significantly lower when compared to the control group. In subgroup analysis, the similar result was also noted in patients with BMI ≥ 25 when compared to patients with BMI < 25, while there was no significant difference between men and women, age ≥ 50 years versus age < 50 years. The incidence of PULS 1-2 ureteral injury in the bladder emptying group was lower than the control group (35% vs. 55%, P = 0.045). The ureteral injury in distal ureteral was less frequently noted in bladder emptying group than the control group (22.5% vs. 55%, P = 0.006); however, there was no significant difference in middle and upper ureter (P > 0.05).

CONCLUSION

Emptying the bladder before UAS insertion can effectively reduce the UAS insertion resistance and the risk of distal ureteral injury in RIRS.

Comparison of commonly utilized ureteral access sheaths: A prospective randomized trial

OBJECTIVE

We aimed to evaluate and compare the functional characteristics, safety profile and effectiveness of two commonly used ureteral access sheaths (UAS) during flexible ureteroscopy.

METHODS

After institutional review board approval, patients with proximal ureteral or kidney stones requiring flexible ureteroscopy and UAS were prospectively randomized to group I or group II according to the type of access sheath used. Primary outcome was incidence of intraoperative complications.

RESULTS

Eighty-eight patients were enrolled in the study, 44 patients in each group. Sheath size 12/14 FR was used in both cohorts. Median (IQR) stone size was 10 mm (7-13.5) and 10.5 mm (7.37-14) in group I and II respectively (p = 0.915). Nineteen and twenty patients, in group I and II respectively, were pre-stented. Subjective resistance with insertion of the UAS was observed in 9 and 11 patients in group I and II respectively (p = 0.61) while failed insertion was encountered in one patient in group I. Traxer grade 1 ureteral injury was noted in 5 and 6 patients in group I and II respectively while grade 3 injury was seen in 1 patient for both cohorts (p = 0.338). There was less resistance for UAS placement in pre-stented patients (p = 0.0202) but without significant difference in ureteric injury incidence (p = 0.175). Emergency department visits were encountered in 7 (group I) and 5 patients (group II) (p = 0.534).

CONCLUSIONS

The studied UASs were comparable regarding safety and efficacy in the current study. Pre-stented and dilated ureters had less resistance to insertion although this was not reflected on incidence of ureteric injury.

Evaluation of ureteral injuries caused by ureteral access sheath insertion during ureteroscopic lithotripsy

OBJECTIVE

To evaluate ureteral injuries caused by insertion of a 13-Fr ureteral access sheath and identify factors (other than pre-stenting) that are predictive of ureteral injury.

METHODS

We enrolled 201 patients who underwent ureteroscopic lithotripsy (URSL). We excluded 80 patients who underwent ureteral stent insertion before URSL, 10 patients who did not use a ureteral access sheath, and 2 patients in whom a ureteral access sheath could not be inserted. In total, 109 patients were analyzed; all underwent insertion of a 13-Fr ureteral access sheath. We investigated ureteral injuries using the Traxer ureteral injury scale.

RESULTS

There were 21 (19.3%) cases of ureteral access sheath-related ureteral injury, including 11 (10.1%) grade 2 cases and 10 (9.2%) grade 3 cases. The ureteral injury location was the proximal ureter in 20 cases (18.3%), middle ureter in one case (0.9%), and distal ureter in zero cases. Multiple logistic regression analysis showed that male sex and smaller stone diameter were significant predictive factors for ureteral injury (p = 0.037, odds ratio [OR]: 5.19, 95% confidence interval [CI]: 1.11-24.3 and p = 0.02, OR: 0.83, 95% CI: 0.71-0.97, respectively). Postoperative ureteral stricture did not occur in any cases.

CONCLUSIONS

The rate of ureteral injury caused by a 13-Fr ureteral access sheath was considerable, and most ureteral injuries occurred in the proximal ureter. Male sex and smaller stone diameter were significant predictive factors for ureteral injury. The proximal ureter should be confirmed when using a 13-Fr ureteral access sheath, particularly in male patients and patients with small stones.

Current evidence for suction in endourological procedures: comprehensive review of literature

PURPOSE OF REVIEW

To identify the latest advances on the utilization of suctioning devices in the surgical treatment of urinary stones.

RECENT FINDINGS

Advances are being made to incorporate suction and pressure control capabilities in percutaneous and ureteroscopic lithotripsy. Multiple retrospective studies and few prospective studies have shown that suctioning with minimally invasive percutaneous nephrolithotomy, commonly referred to as Super MiniPerc, can lead to better stone-free rates (SFR) and shorter operative time with lower incidence of infectious complications. Suctioning during retrograde intrarenal surgery (RIRS) has mainly been achieved through suctioning ureteral access sheath. Here as well, the incorporation of suction improved the SFR, but most importantly, reduced the risk of postoperative infectious complications.

SUMMARY

Theoretically suction in endourological procedures could facilitate stone debris removal and could reduce intrarenal pressure at the same time allowing for increased irrigation flow potentially decreasing operation time and infectious complications. These claims are supported in contemporary clinical studies, reporting superior SFR and reduced postoperative infectious complications in both percutaneous nephrolithotomy and RIRS.

Clinical Factors to Predict Difficult Ureter during Ureteroscopic Lithotripsy

Objective

To identify risk factors for difficult ureters during ureteroscopic lithotripsy and to determine the appropriate indications for preoperative stenting.

Methods

We retrospectively analyzed 156 ureteroscopic procedures for upper urinary tract stones after excluding those with preoperative stenting or percutaneous nephrostomy. Traceability of the ureter was assessed by two urologists. Traceability was defined as positive if either or both urologists discerned the ureter in all slices on preoperative plain computed tomography. Patients' backgrounds were compared between the nondifficult ureter and difficult ureter groups. A multivariate logistic regression model was used to evaluate the relationships between difficult ureters and other clinical factors.

Results

Of 156 patients, 31 (19.9%) were classified into the difficult ureter group. The positive traceability was higher in the nondifficult ureter group (48.3% vs. 83.2%, P < 0.001). The major axis was smaller in the difficult ureter group than in the nondifficult ureter group (8.8 ± 3.9 mm vs. 10.9 ± 4.5 mm, P < 0.018). A major axis <8 mm (odds ratio: 4.495, 95% confidence interval: 1.791-11.278, and P=0.001), negative traceability (odds ratio: 7.565, 95% confidence interval: 2.693-21.248, and P < 0.001), smoking status (odds ratio: 3.196, 95% confidence interval: 1.164-8.773, and P=0.024), and absence of diabetes mellitus (odds ratio: 5.813, 95% confidence interval: 1.121-30.142, and P=0.036) were identified as independent predictors of difficult ureters on multivariate logistic regression analysis.

Conclusion

Patients with smaller stones, negative traceability, ongoing tobacco consumption, and absence of diabetes mellitus were at higher risk of difficult ureters. In these patients, preoperative stenting may be considered.

International Alliance of Urolithiasis guideline on retrograde intrarenal surgery

OBJECTIVES

To set out the second in a series of guidelines on the treatment of urolithiasis by the International Alliance of Urolithiasis that concerns retrograde intrarenal surgery (RIRS), with the aim of providing a clinical framework for urologists performing RIRS.

MATERIALS AND METHODS

After a comprehensive search of RIRS-related literature published between 1 January 1964 and 1 October 2021 from the PubMed database, systematic review and assessment were performed to inform a series of recommendations, which were graded using modified GRADE methodology. Additionally, quality of evidence was classified using a modification of the Oxford Centre for Evidence-Based Medicine Levels of Evidence system. Finally, related comments were provided.

RESULTS

A total of 36 recommendations were developed and graded that covered the following topics: indications and contraindications; preoperative imaging; preoperative ureteric stenting; preoperative medications; peri-operative antibiotics; management of antithrombotic therapy; anaesthesia; patient positioning; equipment; lithotripsy; exit strategy; and complications.

CONCLUSION

The series of recommendations regarding RIRS, along with the related commentary and supporting documentation, offered here should help provide safe and effective performance of RIRS.

Best Practice in Interventional Management of Urolithiasis: An Update from the European Association of Urology Guidelines Panel for Urolithiasis 2022

PURPOSE

The European Association of Urology (EAU) has updated its guidelines on clinical best practice in urolithiasis for 2021. We therefore aimed to present a summary of best clinical practice in surgical intervention for patients with upper tract urolithiasis.

MATERIALS AND METHODS

The panel performed a comprehensive literature review of novel data up to May 2021. The guidelines were updated and a strength rating was given for each recommendation, graded using the modified Grading of Recommendations, Assessment, Development, and Evaluations methodology.

RESULTS

The choice of surgical intervention depends on stone characteristics, patient anatomy, comorbidities, and choice. For shockwave lithotripsy (SWL), the optimal shock frequency is 1.0-1.5 Hz. For ureteroscopy (URS), a postoperative stent is not needed in uncomplicated cases. Flexible URS is an alternative if percutaneous nephrolithotomy (PCNL) or SWL is contraindicated, even for stones >2 cm. For PCNL, prone and supine approaches are equally safe. For uncomplicated PCNL cases, a nephrostomy tube after PCNL is not necessary. Radiation exposure for endourological procedures should follow the as low as reasonably achievable principles.

CONCLUSIONS

This is a summary of the EAU urolithiasis guidelines on best clinical practice in interventional management of urolithiasis. The full guideline is available at https://uroweb.org/guidelines/urolithiasis.

PATIENT SUMMARY

The European Association of Urology has produced guidelines on the best management of kidney stones, which are summarised in this paper. Kidney stone disease is a common condition; computed tomography (CT) is increasingly used to diagnose it. The guidelines aim to decrease radiation exposure to patients by minimising the use of x-rays and CT scans. We detail specific advice around the common operations for kidney stones.

Comparison of retrograde intrarenal stone surgery with and without a ureteral access sheath using kidney injury molecule-1 (KIM-1) levels: a prospective randomized study

The objective is to compare patients who underwent retrograde intrarenal surgery with and without a ureteral access sheath (UAS) using kidney injury molecule-1 (KIM-1) levels. We also examined the difference in kidney damage between standard and dual lumen UAS. Sixty patients diagnosed with kidney stones and scheduled for RIRS were randomized into three groups: RIRS without UAS (Group 1), 11Fr/13Fr Boston scientific Navigator™ UAS (Group 2), and 11Fr/13Fr dual lumen ClearPetra™ UAS (Group 3). Data were prospectively collected in consecutive patients. Urine KIM-1/Cr levels were measured preoperatively, at postoperative 4 h, and on a postoperative day 14. Stone size, location, number, pre- and postoperative stent use, operation time, stone-free rate (SFR), post-ureteroscopic lesion scale (PULS) grade, hospitalization duration, and complications were recorded. There was no significant difference in demographical parameters and preoperative KIM-1/Cr levels among the groups. Postoperative 4th-hour urine KIM-1/Cr levels were higher in patients without UAS than patients with UAS (1.86, 0.67, 0.63 Groups 1, 2, 3, respectively). In comparing group 1 with groups 2 and 3 separately, Group 1 had a statistically significantly higher value than both groups (p = 0.002, p = 0.001, respectively). According to UAS type, there was no significant difference between groups 2 and 3. The use of UAS during RIRS has been shown to reduce kidney injury in the evaluation with KIM-1. Different UAS types on kidney injury and which one can protect the kidneys more during the procedure; will be elucidated by prospective randomized studies involving larger patient groups and UAS types.

Fluoroscopy-free RIRS on the second session after ureteral stent placement

Aim:

Fluoroscopy is used in some stages of the conventional Retrograde Intrarenal Surgery (RIRS) procedure and is beneficial. On the other hand, radiation exposure is its most obvious disadvantage. As a subgroup, we aimed to show that fluoroscopy-free technique is safe and effective in patients who underwent RIRS after passive dilatation.

Materials and methods:

Between October 2018 and April 2020, 54 cases of second session RIRS of renal stones performed by a single surgeon were retrospectively evaluated. Patients’ demographic characteristics (age, gender), stone features (laterality, size, number, volume, and location), mean operative time, and, perioperative and postoperative complications, as well as the stone-free rate (SFR), were all retrospectively evaluated. The results were classified as stone free, clinical insignificant residual fragments (CIRF), and presence of residual stones. Complications were graded using the Clavien–Dindo classification system. We used a modified surgical technique.

Results:

All of complications were minor. There were no major complications (Clavien grade III–IV). The stone-free rate was 70.3% (38/54) on the first day after surgery and 83.3% (45/54) 1 month afterward, respectively. If we accept the absence of residual stone as success, we can say that it is about 91% successful in the first month.

Conclusion:

This technique has a high stone-free success rate and a low complication rate without the use of radiation. For surgeons experienced in endourology, we can say that the fluoroscopy-free technique is safe and effective in secondary-session RIRS cases which passive dilatation was performed by inserting a ureteral catheter before.

Comparison of retrograde intrarenal stone surgery with and without a ureteral access sheath using kidney injury molecule-1 (KIM-1) levels: a prospective randomized study

The objective is to compare patients who underwent retrograde intrarenal surgery with and without a ureteral access sheath (UAS) using kidney injury molecule-1 (KIM-1) levels. We also examined the difference in kidney damage between standard and dual lumen UAS. Sixty patients diagnosed with kidney stones and scheduled for RIRS were randomized into three groups: RIRS without UAS (Group 1), 11Fr/13Fr Boston scientific Navigator™ UAS (Group 2), and 11Fr/13Fr dual lumen ClearPetra™ UAS (Group 3). Data were prospectively collected in consecutive patients. Urine KIM-1/Cr levels were measured preoperatively, at postoperative 4 h, and on a postoperative day 14. Stone size, location, number, pre- and postoperative stent use, operation time, stone-free rate (SFR), post-ureteroscopic lesion scale (PULS) grade, hospitalization duration, and complications were recorded. There was no significant difference in demographical parameters and preoperative KIM-1/Cr levels among the groups. Postoperative 4th-hour urine KIM-1/Cr levels were higher in patients without UAS than patients with UAS (1.86, 0.67, 0.63 Groups 1, 2, 3, respectively). In comparing group 1 with groups 2 and 3 separately, Group 1 had a statistically significantly higher value than both groups (p = 0.002, p = 0.001, respectively). According to UAS type, there was no significant difference between groups 2 and 3. The use of UAS during RIRS has been shown to reduce kidney injury in the evaluation with KIM-1. Different UAS types on kidney injury and which one can protect the kidneys more during the procedure; will be elucidated by prospective randomized studies involving larger patient groups and UAS types.

Flexible ureteroscopy without ureteral access sheath

INTRODUCTION

Ureteral access sheath (UAS) is widely used in flexible ureteroscopy and laser lithotripsy (FURS) based on better stone-free rates, lower intrarenal pressure and fewer complications. However, it also rises surgical costs and may injure the ureteral wall. The main objective of our study is to compare safety and efficacy of FURS with and without UAS to evaluate whether its use is justified in all cases.

MATERIALS AND METHODS

We performed a retrospective observational analytic study based on a prospective database. A total of 241 consecutive patients who underwent FURS for upper ureter and renal stones between January 2018 and May 2020 were included for analysis and divided into two groups upon UAS use. We compared demographic data, stone characteristics, prestenting, operative time, need for ureteral stent, postoperative urinary tract infection, renal colic and need for ancillary procedures.

RESULTS

A total of 198 patients (82.2%) were included in the group without UAS. Operative time was significantly shorter in the group of patients without UAS than those with UAS (64.6 minutes ± 29.5 vs. 89.9 minutes ± 2.8 respectively; p 0.010). Both groups had similar rates of colic pain and urinary tract infection. Ancillary procedures were more frequent in the UAS group (37.2 vs. 21.2%; p 0.026), but significance was lost in multivariate assessment.

CONCLUSION

FURS without UAS seems to be as safe as FURS with UAS but requires less ancillary procedures. An additional advantage is 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.

Advanced ureteroscopic techniques for the management of kidney stones

PURPOSE OF REVIEW

Recent years witnessed significant changes in the endourological management of renal tones because of the development of new, more advanced instruments. Retrograde intrarenal surgery (RIRS) has gained particular advantage from such technological progress and now tends to be considered the gold standard treatment for uncomplicated less than 20 mm renal stones. Using a step-by-step approach, this review aims to highlight current achievements but also unsolved problems in RIRS.

RECENT FINDINGS

Several technical details of RIRS, including preoperative stenting, use of ureteral access sheets, lithotripsy method, and renal drainage, remain open to discussion and linked to surgeon's preference. Moreover, there is a wide range of variation in efficacy and safety data, with major complications being episodic but often under-reported.

SUMMARY

RIRS has gained increased popularity among the urological community. This is certainly because of the continuous technological advancements, which have continuously improved the RIRS performance but also to the perception of ease and safety of this procedure when compared with the other available treatment modalities, particularly percutaneous nephrolitotomy. Indeed, the reported advances in RIRS technique have significantly improved the outcomes of this procedure but care should be taken not to underestimate its potential challenges.

Prestenting Versus Nonprestenting on the Outcomes of Flexible Ureteroscopy for Large Upper Urinary Stones: A Systematic Review and Meta-Analysis

INTRODUCTION

The purpose of this article is to evaluate the efficacy and safety of prestenting (PS) versus non-PS (NPS) of flexible ureteroscopy (fURS) to treat large upper urinary stones.

METHODS

We conducted a systematic literature research of PubMed, Ovid, Scopus (up to August 2019), and citation lists to identify eligible studies. All studies comparing PS versus NPS of fURS were included. Data were analyzed using the Cochrane Collaboration's Review Manager (RevMan) 5.3 software.

RESULTS

Overall, 7 studies including 3,145 patients (PS 1,408; NPS 1,737) were included in this article. PS group was associated with older age (weighted mean difference [WMD] 0.91 year; p < 0.001) and more male patients (odds ratio [OR] 1.34; p < 0.001). There were no statistical differences between PS and NPS in BMI (WMD 0.34 kg/m2; p = 0.13), stone size (WMD 0.13 mm; p = 0.77), and operative time (WMD 0.44 min; p = 0.86). Compared with NPS, PS showed better initial success rate (OR 4.04; p < 0.001) and higher SFR (OR 1.64; p < 0.001). There were no statistical differences for complications (OR 0.84; p = 0.42) and Clavien-Dindo score ≥3 complications (OR 1.04; p = 0.93).

CONCLUSION

PS could improve initial success rate and avoid secondary general anesthesia for first ureteral access sheath failed patients. PS could provide better SFR than NPS in the treatment of large upper urinary stones with fURS.

Iatrogenic ureteral injuries: a case series analysis with an emphasis on the predictors of late ureteral strictures and unfavorable outcome in different surgical specialties

INTRODUCTION AND HYPOTHESIS

We aimed to report the demographics and management of iatrogenic ureteral injuries (IUIs) with different surgical specialties. Moreover, our goal was to analyze the predictors of late ureteral strictures and secondary intervention after primary surgical management, and the final effect on the kidney.

METHODS

A retrospective study, between 2006 and 2019, enrolled all patients undergoing urological, abdominal, and pelvic surgeries performed through open, laparoscopic, or endoscopic means. If IUIs were discovered intraoperatively, they were managed either by internal stent or surgical intervention following the standard procedure. For IUIs discovered postoperatively, either percutaneous nephrostomy (PCN) or double J (DJ) ureteral stents were inserted for later endoscopic or surgical management. The final outcomes were divided into two groups: patients with successful primary outcomes and those who required secondary intervention later. All predictors were compared between the two groups.

RESULTS

Forty-eight patients were reviewed: 23 out of 48 (48%) from obstetrics and gynecology (ob/gyn) involving the lower ureter primarily with overall favorable outcomes (82%), 15 (31%) colorectal, and 10 (21%) urology with serious injuries affecting men in the upper ureter. The primary management included open surgery in 12 patients, and drainage (PCN or DJ) in 36 patients. Restoration of ureteral anatomy and kidney function was achieved in all, but 18 cases required a secondary correction, either endoscopically or surgically. Both early and late discovery resulted in the same outcome. On bivariate analysis, only the side of the injury (left side, p = 0.03), and the specialty (colorectal cancer surgeries, p = 0.01) were predictors for late ureteral strictures, and both sustained their significance in multivariate regression analysis.

CONCLUSION

Iatrogenic ureteral injuries associated with ob/gyn surgeries involve the lower ureter, primarily with overall favorable outcomes (82%). Serious ureteroscopic IUIs affect men in the upper ureter with greater frequency. IUIs on the left side and colorectal cancer surgeries are the predictors for late strictures and secondary interventions.

Evaluation of the Impact of Ureteroscope, Access Sheath, and Irrigation System Selection on Intrarenal Pressures in a Porcine Kidney Model

Introduction: Elevated intrarenal pressure (IRP) during flexible ureterorenoscopy (FURS) is a predictor of postoperative complications. The aim of this study is to evaluate IRP during FURS in a porcine kidney model to determine the safest combination of irrigation device, ureteral access sheath (UAS), and ureteroscope. Methods: Urinary tracts were harvested from Landrace pigs slaughtered for the food chain. Two flexible ureteroscopes, 8.7F and 9.5F, were evaluated. Irrigation systems evaluated included the following: TraxerFlow™ (Rocamed, France), SAPS™ single action pumping system (Boston Scientific), Pathfinder Plus™ (Utah Medical), and a manual "bag squeeze." This experiment was conducted with no UAS, followed by an 11/13F UAS and then a 12/14F UAS. IRPs were measured in the prepared porcine kidney during all possible combinations of scope, UAS, and irrigation system. Results: Pressures were significantly reduced when using 12/14F UAS compared with 11/13F UAS (16.45 ± 5.3 cmH₂O vs 32.73 ± 35.66 cmH₂O, p = 0.006), and when using 11/13F UAS compared with no UAS (32.73 ± 35.66 cmH₂O vs 49.5 ± 29.36 cmH₂O, p = 0.02). Pressures were significantly reduced with the 8.7F scope compared with the 9.5F scope (24.1 ± 21.24 cmH₂O vs 41.68 ± 34.5 cmH₂O, p = 0.001). SAPS generates significantly greater IRP than TraxerFlow, Pathfinder Plus, and a "bag squeeze" (p < 0.05). The most dangerous combination was using the SAPS, no UAS, and larger ureteroscope leading to an IRP of 100.6 ± 16.1 cmH₂O. The safest combination was using Pathfinder Plus with a 12/14F UAS and smaller ureteroscope giving an IRP of 11.6 ± 3.65 cmH₂O. Conclusion: IRPs are reduced by selecting larger UAS and a small ureteroscope. The SAPS generates significantly higher IRPs than other irrigation systems. To maintain safe IRPs during FURS, urologists should use large UAS, narrow ureteroscopes, and be cautious in the selection of an irrigation device.

Ureteral Strictures Following Ureteroscopic Stone Treatment

Background and Purpose: Ureteral stricture is a rare, but serious complication following ureteroscopy (URS) for stones. The aim of this study was to investigate how many patients ended up with a ureteral stricture after URS at our hospital and how these were treated. We also wanted to identify potential risk factors for postendoscopic stricture formation. Materials and Methods: A retrospective evaluation of 1001 URSs for stone treatment at the day-case surgery unit between 2013 and 2018 was performed. Data on pretreatment status, the surgical procedure, and follow-up were recorded. Exact χ² and independent samples t-tests were used comparing data among those who developed strictures and those who did not. Multiple logistic regression was performed analyzing risk factors for stricture formation. Results: In total, 1001 URSs were performed in 725 patients, 289 women and 436 men. Of these, 995 cases were eligible for analysis. At follow-up with CT after 3 months, 28 (3.0%) strictures were identified. Of these, 20 received endourologic treatment with balloon dilatation of which 15 (75%) were effective. Definitive treatment in the 13 patients with failed or unattempted endourologic treatment included nephrectomy, reconstructive surgery, permanent nephrostomy, or observation with no further treatment. In multiple regression analysis, use of ureteral access sheath (UAS; odds ratio [OR] 4.6, p = 0.011), ureteral perforation (OR 11.8, p < 0.0001), and surgical time >60 minutes (OR 5.7, p < 0.005) were found to be risk factors for stricture formation. Conclusion: Ureteral stricture is a rare complication of URS. Balloon dilatation should be the first line of treatment. Use of UAS, perforation, and excessive operating time were found to be risk factors for postendoscopic ureteral stricture formation. Special attention to these risk factors should be given to reduce the incidence of ureteral strictures.

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.

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.

Correlation of Operative Time with Outcomes of Ureteroscopy and Stone Treatment: a Systematic Review of Literature

PURPOSE OF REVIEW

To present the latest evidence related to the impact of increased operative times in retrograde intrarenal surgery and identify possible important factors that can facilitate ureteroscopy procedures.

RECENT FINDINGS

Ureteroscopy constitutes the mainstay treatment of renal stones and is characterized by a huge variation in techniques and instrumentation. It has been suggested that increased operative times can mitigate the outcomes of the procedures by increasing complication rates. Nevertheless, little is known about the time limits, above which complications are likely to occur. Furthermore, complication rates in different procedure durations have not yet been assessed. Prolonged operative times are linked to increased complication rates in ureteroscopy. Stone complexity, patient risk factors, surgeon experience, bilateral surgery, and instrumentation constitute important factors that can hamper or facilitate a procedure and should be taken into account beforehand. Keeping procedural times below 90 min can dissuade potential predicaments and achieve improved stone-free rates.

A comprehensive literature-based equation to compare cost-effectiveness of a flexible ureteroscopy program with single-use versus reusable devices

PURPOSE

To critically review all literature concerning the cost-effectiveness of flexible ureteroscopy comparing single-use with reusable scopes.

MATERIALS AND METHODS

A systematic online literature review was performed in PubMed, Embase and Google Scholar databases. All factors potentially affecting surgical costs or clinical outcomes were considered. Prospective assessments, case control and case series studies were included.

RESULTS

741 studies were found. Of those, 18 were duplicated and 77 were not related to urology procedures. Of the remaining 646 studies, 59 were considered of relevance and selected for further analysis. Stone free and complication rates were similar between single-use and reusable scopes. Operative time was in average 20% shorter with digital scopes, single-use or not. Reusable digital scopes seem to last longer than optic ones, though scope longevity is very variable worldwide. New scopes usually last four times more than refurbished ones and single-use ureterorenoscopes have good resilience throughout long cases. Longer scope longevity is achieved with Cidex and if a dedicated nurse takes care of the sterilization process. The main surgical factors that negatively impact device longevity are lower pole pathologies, large stone burden and non-use of a ureteral access sheath. We have built a comprehensive fi nancial costeffective decision model to fl exible ureteroscope acquisition.

CONCLUSIONS

The cost-effectiveness of a fl exible ureteroscopy program is dependent of several aspects. We have developed a equation to allow a literature-based and adaptable decision model to every interested stakeholder. Disposable devices are already a reality and will progressively become the standard as manufacturing price falls.

Sheathless and fluoroscopy-free retrograde intrarenal surgery: An attractive way of renal stone management in high-volume stone centers

Objective

To evaluate the efficacy and safety of sheathless and fluoroscopy-free flexible ureterorenoscopic laser lithotripsy (FURSL) for treating renal stones.

Methods

Between May 2015 and May 2017, 135 patients with renal stones treated with sheathless and fluoroscopy-free FURSL were prospectively evaluated. Our technique involved a semi-rigid ureteroscopic assessment of the ureter, and the guidewire was left in situ to railroad the flexible ureteroscope. A holmium laser was used to fragment and dust the stones; fragments were neither grasped nor collected.

Results

The study population consisted of 135 patients including 85 males (62.96%) and 50 females (37.04%) with a mean age of 40.65 years (range: 3–70 years) were evaluated. The mean stone size was 17.23 mm (range: 8–41 mm). Complete stone-free status was achieved in 122 (90.37%) patients and clinically insignificant residual fragments (CIRF) in two (1.48%), while residual stones were still present in 11 (8.15%) patients. Postoperative complications occurred in 23 (17.4%) cases and were mostly minor, including fever in 17 (12.6%), pyelonephritis in four (3.0%), subcapsular hematoma in one (0.7%) and steinstrasse in one (0.7%). These complications were Clavien I-II, GI in 17 (12.6%) patients, GII in five (3.7%), and Clavien IIIb in one (0.7%). No major complications were observed. Stone size ≥2 cm, operative time ≥30 min, and lasing time ≥20 min were significantly associated with a higher rate of complications and lower stone-free rates upon univariate analysis (p<0.05).

Conclusion

Sheathless and fluoroscopy-free FURSL are effective and safe for renal stone management, especially for stones under 2 cm in diameter. This process is a feasible option for avoiding sheath complications, which can protect surgeons from the negative effects of radiation.

Practice patterns of ureteral access sheath during ureteroscopy for nephrolithiasis: a survey among endourologists worldwide

Background

The use of ureteral access sheath (UAS) during ureteroscopy is controversial. We aimed to explore practice patterns of UAS during ureteroscopy for nephrolithiasis among endourologists worldwide.

Methods

A 15-question survey was designed using the SurveyMonkey® platform. The questions covered the background and professional experience of the potential respondents, indications for UAS insertion, UAS caliber and possible complications associated with its use.

The questions were anonymously tabulated in order to determine practice patterns of UAS during ureteroscopy for nephrolithiasis among endourologists.

The survey was then distributed via e-mail to all the Endourological Society members.

Results

216 members responded. 99.53% of the respondents practice as endourologists, 63.4% are fellowship trained and 74.4% are at least 6 years post-fellow. 73.2% practice in an academic facility. 77.3% perform at least 100 ureteroscopies annually. 46 and 76% routinely use UAS for the treatment of ureteral and kidney stones, respectively. In both cases, the 12/14 access sheath is the most common. 42% use UAS in primary ureteroscopy. 90.3% believe that a double J stent insertion is not mandatory prior to UAS insertion. 79.1% think the use of UAS does not increase postoperative complications rate, and if the latter does encounter, then most likely it is either a ureteral stricture (93.2%) or pain (48%).

Conclusions

UAS is commonly used by highly skilled endourologists during ureteroscopy. 12/14 UAS is mostly used. Ureteral stricture and post-operative pain are proposed as possible complications following UAS introduction, however pre-stenting is not mandatory as overall low complication rate is expected.

The efficacy of flexible ureteroscopy lithotripsy and miniaturized percutaneous nephrolithotomy for the treatment of renal and proximal ureteral calculi of ≤2 cm: A retrospective study

To assess the clinical effect of miniaturized percutaneous nephrolithotomy (MPCNL) and flexible ureteroscopy lithotripsy (FURL) for the treatment of renal and proximal ureteral calculi of ≤2 cm.A retrospective analysis was carried out on clinical data of 106 patients with kidney or upper urethral calculi. Among these patients, 58 underwent the MPCNL, and 48 received FURL. Stone-free rates, operating time, blood loss, hemoglobin drop, length of hospital stay, complications, and renal damage indexes were compared.The stone removal rates of the FURL and MPCNL groups were 81.25% versus 87.93% (p > .05). Although operating time was significantly shorter in the MPCNL group, hospital stays were significantly shorter in the FURL group. In addition, pooled analysis showed that mean estimated blood loss was significantly higher in the PCNL group but the hemoglobin decline of the FURL group and PCNL group had no significant difference. The PCNL group had no significant difference in complications compared to the FURL group. Differences on the creatinine levels and urea nitrogen levels before the operation and after the operation were not statistically significant.FURL is an effective method for treating renal stone. FURL not only had a similar stone-free rate as compared to MPCNL but also was associated with less blood loss and more favorable recovery time. However, FURL had a longer operative time.

Efficacy and Safety of Ultrasonic Longitudinal-Axis Vibration for the Reduction of Ureteral Access Sheath Insertion Force: A Randomized Controlled Trial in a Porcine Model

PURPOSE

Excessive bulking force during ureteral access sheath (UAS) placement may induce injury. The sliding friction between surfaces can be reduced with the application of ultrasonic vibration. We investigated the efficacy and safety of an ultrasonic vibration transducing device for reducing the maximal ureteral access sheath insertion force (UASIF).

MATERIALS AND METHODS

A device was developed for transducing ultrasonic longitudinal-axis vibration onto the UAS at an adjustable amplitude and frequency while measuring the degree of UASIF. In the pilot study, six porcine models were used to investigate the optimal amplitude and frequency of vibration and to calculate sample size. Twelve porcine models were utilized in a randomized controlled trial. Resected ureters were pathologically evaluated for ureteral injury.

RESULTS

The transduction of ultrasonic vibration at an amplitude of 0.04 g and a frequency of 18,000 Hz resulted in a maximal UASIF reduction of 36.4% (interquartile range 32.7-43.1). Maximal UASIF tended to decrease with increasing vibration frequency. No significant differences in UASIF reductions were observed according to amplitude. In the randomized controlled trial, the maximal UASIF reduction was 37.0% (interquartile range 21.4-44.2). Grade II injury was pathologically diagnosed in 8.3% (1/12) of the ureters in both groups.

CONCLUSIONS

The transduction of ultrasonic longitudinal-axis vibration onto the UAS reduces maximal UASIF and does not harm the ureter. Reducing the velocity of sheath insertion may further reduce maximal UASIF.

Comparison of utilization of pressurized automated versus manual hand irrigation during ureteroscopy in the absence of ureteral access sheath

This study compared patient outcomes following irrigation applied using an automated pressure system (AP) to hand irrigation utilizing a syringe (HI) during ureteroscopy. Retrospective chart review was performed to evaluate ureteroscopy procedures without a ureteral access sheath. Procedures in which irrigation was applied by AP were compared to those with HI. Statistical analyses included chi-squared tests and Student's t tests. The AP group contained 206 procedures and the HI group, 25. The AP and HI groups were 54.9% and 36% male, respectively. Mean ages were 53.7 ± 18.9 years in the AP group and 44.0 ± 18.5 years in the HI group. Complication rates were 11.2% in the AP and 8.3% in the HI group (P > 0.99). One stone retrieval failure and one stone recurrence occurred in the HI group; one patient had residual stone in the AP group. No urinary tract infections occurred in the HI group; in the AP group, urinary tract infections occurred in 1.9% of cases. The postoperative pain incidence was equivalent (P = 0.498). The AP group had one subcapsular hematoma; no calyceal ruptures occurred in either group. In conclusion, irrigation applied by an automated setup appears safe, with similar outcomes to irrigation applied with a handheld syringe.

Comparison of Safety and Efficacy in Preventing Postoperative Infectious Complications of a 14/16F Ureteral Access Sheath with a 12/14F Ureteral Access Sheath in Flexible Ureteroscopic Lithotripsy

PURPOSE

There are a variety of ureteral access sheath (UAS) lengths (13-55 cm) and diameters (9.5/11.5F-16/18F) available in the market. However, urologists are faced with a dilemma when choosing the ideal UAS diameter. Thus, we evaluated a case-control study of the efficacy and safety of 12/14F and 14/16F UASs in flexible ureteroscopic lithotripsy.

MATERIALS AND METHODS

A retrospective case-control study was evaluated with patients who were treated with flexible ureteroscopic lithotripsy for urinary calculi in a West China hospital from 2008 to 2017. Patients deployed a 12/14F UAS were divided into group A, and the others were divided into group B. The primary outcome was the postoperative infectious complication rate after the operation, including fever and sepsis. The second outcome included safety, lithotripsy time, and the stone-free rate.

RESULTS

There were 1139 patients in total included in our study, with 593 patients divided into group A and 546 divided into group B. There was no significant difference between the baselines of the two groups' patients. The patients in group A had a significantly lower postoperative rate compared to the patients in group B (6.4% vs 1.6%). The 14/16F UAS also worked better in high-risk patients, such as patients with stones >2 cm or patients with infectious stones (7.6% vs 1.6%, 15.0% vs 3.1%, respectively).

CONCLUSIONS

Our study found that the 14/16F UAS showed an obvious advantage in preventing postoperative infectious complications in flexible ureteroscopic lithotripsy compared to the 12/14F UAS.

How bothersome double-J ureteral stents are after semirigid and flexible ureteroscopy: a prospective single-institution observational study

PURPOSE

To evaluate in details the actual extent of double-J stent-related symptoms after semirigid (URS) and flexible (RIRS) ureteroscopy using a validated questionnaire.

METHODS

We asked to complete the Ureteric Stent Symptoms Questionnaire (USSQ) to all stone patients undergoing URS or RIRS with stent placement from 2010 to 2015. Stent-related symptoms' prevalence, severity, and impact on daily life were analyzed using descriptive statistics and five-order Likert scales. Subgroups analyses were performed.

RESULTS

232 patients completed the USSQ. Stents had a deep impact on urinary symptoms (daily frequency ≥ 1 per hour 59.1%, ≥ 1 nocturnal micturition 90.1%, urgency 86.6%, burning 82.3%) that represented a problem for 88.4% of patients. 83.2% complained of pain, mostly in the kidney (67.9%) or in the bladder area (31.3%), particularly during physical activity (72.9%) and micturition (77.0%). Pain interfered with everyday life in 92.2%. General health, working, and sexual activity were also affected. 62.0% of patients would be dissatisfied (51.6% unhappy or terrible) if further ureteral stenting was proposed in future. Younger patients and females were more affected. Limitations include observational design and lack of baseline evaluation.

CONCLUSIONS

Ureteral stents are responsible for significant urinary symptoms and pain after semirigid and flexible ureteroscopy. They also considerably affect general health, working and sexual activity. Urologists should consider it carefully before stenting, inform patients about stent-related symptoms, and minimize stent indwelling time.

Experiencia en el manejo de litiasis renal y ureteral con ureteroscopio flexible y láser holmium en un hospital público de Bogotá: estudio retrospectivo

Objetivos Discutir y evaluar la tasa libre de cálculos y las complicaciones de la ureterolitotomía endoscópica flexible con láser holmium en el manejo de cálculos ureterales y renales basada en la experiencia de un hospital público de iii nivel en Bogotá.

Material and Métodos Estudio retrospectivo en una muestra poblacional en pacientes con litiasis renal y ureteral, tratados con ureteroscopio flexible y láser holmium, evaluándose la tasa libre de cálculos, complicaciones postoperatorias y otros parámetros. El seguimiento se realizó con radiografía de abdomen y urotac al mes del postoperatorio, la tasa libre de cálculos se definió como ausencia de cálculos residuales < 4 mm en la imagen control.

Resultados Se realizaron 44 procedimientos en 43 pacientes con edad promedio de 45 años, tiempo quirúrgico promedio 91,2 min, la tasa libre de cálculos fue del 84% (37/44) en un solo evento quirúrgico; solo un paciente requirió una segunda intervención con posterior tasa libre de cálculos del 100%. La tasa libre de cálculos ureterales fue del 92% (24/26), cáliz superior 100% (2/2), cáliz medio 100%(1/1), cáliz inferior 78% (7/9) y calicial múltiple 50% (3/6). El porcentaje de complicaciones fue del 6,8%.

Conclusiones La ureterolitotomía endoscópica flexible con láser es un procedimiento efectivo y seguro en el manejo de litiasis renal y ureteral con baja incidencia de complicaciones. Observamos que en la mayoría de los pacientes con fragmentos residuales significativos estos se encontraban en cáliz inferior o se trataba de cálculos en múltiples cálices, explicándose por el difícil acceso al cáliz inferior y la carga litiásica.

Rirs through Semi-Rigid Ureteroscope and Holmium Laser in the Treatment of Ureteral Stones Retropulsion

Retrograde displacement of ureteral stones into the renal cavities during ureteroscopic lithotripsy represents a frequent and adverse event that leads to additional procedures (ESWL, PCNL, Retrograde Intra-renal lithotripsy with flexible instruments, DJ stent placement and subsequent EWSL) to obtain full clearence of calculi. All these procedures require a further time of treatment.

Between 1/2008 and 3/2009, a total of 48 patients harbouring proximal (21 cases) and distal (27 cases) ureteral stones underwent Holmium Laser lithotripsy. In 3 patients previous percutaneous nephrostomy was performed to drain the excretory way. In 12 cases (25%) stone retropulsion occurred; in 3 patients in the upper calix and in 5 in the renal pelvis. Only in 4 cases the stone migrated in the lower or medium calix. In 8 cases we attempted the immediate treatment of intrarenal displaced stones by advancing the semi-rigid instrument into the renal cavities. In 2 cases the treatment aborted because of the shortness of ureteroscope. The instillation of lubricating lidocaine jelly prevented in 3 cases furher displacement of stone. Washing with saline solution through nephrostomic catheter allowed an effective mobilization of stone and an easy lasertripsy

RIRS was successful in 4 cases. When flexible devices or immediate ESWL are not available, rigid or semi-rigid retrograde lithotripsy with holmium laser immediately performed after ureteral stone displacement represents a safe and effective method to treat displaced stones. Several tricks are required to obtain a good stone-free rate.

A prospective multicenter European study on flexible ureterorenoscopy for the management of renal stone

Purpose

The aim of this study was to describe the outcomes and the complications of retrograde intrarenal surgery (RIRS) for renal stones in a multi-institutional working group.

Materials and Methods

From 2012 to 2014, we conducted a prospective study including all RIRS performed for kidney stones in 4 European centers. Demographic information, disease characteristics, and perioperative and postoperative data were gathered. Patients and stone data, procedure characteristics, results and safety outcomes were analyzed and compared by descriptive statistics. Complications were reported using the standardized Clavien system.

Results

Three hundred and fifty-six patients underwent 377 RIRS with holmium laser lithotripsy for renal stones. The RIRS was completed in all patients with a mean operative time of 63.5 min. The stone-free status was confirmed endoscopically and through fluoroscopic imaging after the first procedure in 73.6%. The second procedure was performed in twenty patients (5.6%) achieving an overall stone free rate of 78.9%. The overall complication rate was 15.1%. Intra-operative and post-operative complications were seen in 24 (6.7%) and 30 (8.4%) cases, respectively.

Conclusions

RIRS is a minimally invasive procedure with good results in terms of stone-free and complications rate.

[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.

Flexible Ureterorenoscopy for Renal and Proximal Ureteral Stone in Patients with Previous Ureteral Stenting: Impact on Stone-Free Rate and Morbidity

OBJECTIVE

To analyze results (stone-free rate [SFR]) and complications after flexible ureterorenoscopy (f-URS) for renal or lumbar ureteral lithiasis in patients with a previous ureteral stenting (US).

PATIENTS AND METHODS

We conducted a single-center retrospective study, including all f-URS procedures achieved in our department, between January 2004 and December 2010, for renal or lumbar ureteral urinary lithiasis. In total, 497 procedures were performed: 316 procedures in patients with a ureteral stent placed before the surgery for renal colic, sepsis, or renal failure (group 1) and 181 procedures in patients without US (group 2). Success was defined as a complete SFR at 6-month follow-up. Surgical morbidity was defined using the Clavien-Dindo grading system.

RESULTS

Groups 1 and 2 were well balanced in terms of demographic data, number, and size of stones. Ureteral location was significantly higher in group 1 (30.2% vs 16.3%, p = 0.0006). Surgery characteristics were similar in both groups. By univariate analysis, SFR tended to be slightly higher in the group with prior ureteral stenting (72% vs 63%, p = 0.05). SFR for ureteral location was also higher after previous ureteral stenting (81.5% vs 59.4%, p = 0.023). By multivariate analysis, only stone size and number were correlated with f-URS failure. Complication rate was comparable in both groups (10.7% vs 11.8%, p = 0.7).

CONCLUSION

Technical aspects of the f-URS procedure were not modified by ureteral stenting. We found that f-URS in patients with ureteral stenting was not associated with a better SFR, except in case of ureteral location in univariate analysis. Ureteral stenting was not independently related to f-URS outcome by multivariate analysis.

Factors affecting complication rates of retrograde flexible ureterorenoscopy: analysis of 1571 procedures-a single-center experience

PURPOSE

To evaluate the factors affecting complication rates of flexible ureteroscopy and laser lithotripsy (FURSL).

MATERIALS AND METHODS

Data on a total of 1395 patients, with 1411 renal units underwent 1571 procedures with FURSL for renal and/or proximal ureteral stones between April 2012 and January 2016, were retrospectively analyzed. Complications were assessed using the Satava and modified Clavien systems. Univariate and multivariate analyses were done to determine predictive factors affecting complication rates.

RESULTS

The mean patient age in the total procedures was 45.68 ± 14.00 years (range 2-86 years), and the mean stone size was 15.15 ± 8.32 mm (range 5-75 mm). The overall success rate was 95.6 %. A total of 209 (13.3 %) cases suffered from complications with intraoperative complications rates of 5.9 % and postoperative complication rates of 7.3 %. Univariate analysis revealed no significant difference in complication rates in respect of age, gender, body mass index, use of ureteral access sheath, operation time, bleeding disorder, solitary kidney, preoperative stenting, American Society of Anesthesiologists score, repeated procedure or location of stones (all p value >0.05). Complication rates were determined to be significantly affected by stone size (p = 0.026), multiplicity (p = 0.028) and the presence of congenital renal abnormality (p < 0.01). The only significant factor in multivariate analysis was the presence of congenital renal abnormalities (p = 0.02).

CONCLUSIONS

The results of the current study indicated that stone size, stone number and the presence of congenital renal abnormalities were factors affecting complication rates after FURSL, although congenital renal abnormality was the only independent predictor among these risk factors.