Use of ureteral access sheaths in ureteroscopy

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.

Safety and feasability of ureteroscopy for pediatric stone, in children under 5 Years (SFUPA 5): A French multicentric study

INTRODUCTION

Ureteroscopy (URS) can be proposed as first-line therapy for the management of pelvic stones from 10 to 20 mm and for lower ureteric stones in children. However, little is known about the success and the morbidity of URS in young children. Ureteroscopic treatment may present matters in young children because of the small size of the pediatric kidney and the small size of the collecting system.

OBJECTIVE

To assess safety and efficacy of URS for the treatment of urinary stones in children aged of 5 years or less.

STUDY DESIGN

After the institutional ethical board approval was obtained, we conducted a retrospective, analytic, multicentric study that included all URS performed between January 2016 and April 2022 in children aged of 5 years or less. In this non-comparative case series, anonymized pooled data were collected from 7 tertiary care centers of pediatric patients. Endpoints were the one-session SFR at 3 months and per and postoperatives complications. Descriptive statistics were applied to describe the cohort.

RESULTS

Eighty-three patients were included. For them, 96 procedures were performed at the median age of 3.5 years (IQR: 0.8-5) and median weight of 14 Kg (6.3-23). Median stone size was 13 mm (4-45). There were 65 (67 %) renal stones treated with flexible URS, most of which were in the renal pelvis (30 %) and in the lower calix (33 %). A ureteral access sheath was used in 91 % procedures. Preoperative ureteral stent was placed in 52 (54 %) of patients. None of patients had ureteral dilatation. The single-session SFR was 67.4 % (56.3 and 89.2 % for flexible URS and semi-rigid URS respectively) and children require 1.4 procedures to achieve complete stone clearance. The overall complication rate was 18.7 %, most of them were minor (Clavien I-II). Intraoperative perirenal extravasation (Clavien IIIb) due to forniceal rupture was documented in 6.2 % of cases, related to an increased intrapelvic pressure (IPP) performed in a closed pelvicalyceal system.

DISCUSSION

Pediatric urologists should be aware of forniceal rupture based on the presence of extravasation of contrast during endourological procedures especially when they have difficulties to reach lower caliceal stone in small patient.

CONCLUSION

URS in patients aged of 5 years or less, is a complex minimally invasive procedure with reasonable efficacy and low morbidity. Intrarenal stones treated by RIRS in young children carries the risk of additional procedures to complete stone clearance.

Factors affecting the intraoperative calculi excretion during flexible ureteroscopy lithotripsy: an in vitro analysis

OBJECTIVE

To explore the parameters influencing intraoperative calculi excretion (ICE) during flexible ureteroscopy lithotripsy (fURL) using in vitro simulation experiments.

METHODS

3D-printed human kidney models were used to simulate the elimination of gravel during fURL. The factors influencing the ICE during fURL were analyzed by comparing the effects of different degrees of hydronephrosis (mild, moderate, and severe), surgical positions (supine and lateral position), ratios of endoscope-sheath diameter (RESD) (0.625, 0.725, and 0.825), gravel sizes (0.50-1.00 mm, 0.25-0.50 mm, and 0.10-0.25 mm), and ureteral access sheaths (UASs) (traditional UAS and negative-pressure UAS) on ICE.

RESULTS

The impacts of various UAS, RESD, degree of hydronephrosis, surgical positions, and gravel sizes on ICE were all significant (p < 0.05). We found no evidence of multicollinearity for all the independent variables, and the linear regression equation fitted as ICE ( g / min ) = 0.102 + 0.083 ∗ UAS grade - 0.050 ∗ RESD grade - 0.048 ∗ hydronephrosis grade + 0.065 ∗ position grade - 0.027 ∗ gravel size grade (R2 = 0.569).

CONCLUSION

Employing negative-pressure UAS, smaller RESD, milder hydronephrosis, lateral position, and smaller gravel size contribute to improved ICE during fURL. Among them, the adoption of negative-pressure UAS had the most substantial effects.

The optimal ratio of endoscope-sheath diameter with negative-pressure ureteral access sheath: an in vitro research

PURPOSE

To maintain safe intrarenal pelvic pressure (IPP), the combination of flexible ureteroscope (fURS) and traditional ureteral access sheath (T-UAS) should maintain a basic rule that is the ratio of endoscope-sheath diameter (RESD) ≤ 0.75. However, the negative-pressure ureteral access sheath (NP-UAS) may break the rule of negative pressure suction. This study aimed to examine the effect of NP-UAS on IPP and flow rate (FR) with varying RESD.

METHODS

In a 3D-printed renal model, flexible ureteroscopy lithotripsy (fURL) was replicated. Six sizes of fURS paired with 12Fr T-UAS and NP-UAS resulted in six distinct RESDs of 0.63, 0.78, 0.87, 0.89, 0.90, and 0.91. While the irrigation pressure (IRP) was set between 100 and 800 cmH2O and the sucking pressure (SP) was set between 0 and 800 cmH2O, the IPP and FR were measured in each RESD.

RESULTS

NP-UASs can reduce the IPP and increase the FR at the same RESD compared to T-UASs. The IPP decreased with increasing SP with NP-UAS. When RESD ≤ 0.78, T-UAS and NP-UAS can maintain IPP < 40 cmH2O in most circumstances. When RESD = 0.87, it is challenging for T-UAS to sustain IPP < 40 cmH2O; however, NP-UAS can do so. When RESD ≥ 0.89, it is difficult to maintain an IPP < 40 cmH2O even with NP-UAS.

CONCLUSION

NP-UAS can decrease IPP and increase FR compared with T-UAS. To maintain a safe IPP, it is recommended that RESD < 0.85 when utilizing NP-UAS.

Effect of preoperative ureteral stenting on the surgical outcomes of patients with 1-2 cm renal stones managed by retrograde intrarenal surgery using a ureteral access sheath

OBJECTIVE

To assess the surgical results of patients who underwent retrograde intrarenal surgery (RIRS) using a ureteral access sheath (UAS) for management of renal stones sized 1-2 cm compared between patients who did and did not undergo preoperative ureteral stenting.

MATERIALS AND METHODS

This prospective study included 83 patients (aged ≥ 20 years) who underwent RIRS from July 2021 to January 2023. All patients had renal calculi (stone size: 1-2 cm) located within the pelvicalyceal system. 43 and 40 patients were allocated to the non-prestent (group A) and prestent (group B), respectively. Patient baseline characteristics, renal stone details, operative data, stone-free rate (SFR) at 4 weeks and 6 months, and perioperative complications were compared between groups.

RESULTS

The baseline characteristics of all patients were comparable across the groups. Four weeks after surgery, the overall stone-free rate (SFR) stood at 62.65%. In the non-prestent and prestent groups, the SFRs were 58.12% and 67.5%, respectively (p = 0.89). By the sixth month post-surgery, the overall SFR rose to 80.72%. In the non-prestent and prestent groups, the SFRs were 76.74% and 85%, respectively (p = 0.081). No notable differences emerged in other variables, including perioperative complications, between the two groups.

CONCLUSIONS

The SFR showed no significant difference between the prestenting and non-prestenting groups at the 4-week and 6-month postoperative marks. Additionally, there were no substantial differences in complications during surgery and recovery between the groups. Notably, the SFR increased from 4 weeks to 6 months without any additional procedures in either group.

Clinical application of novel integrated suctioning semi-rigid ureteroscopic lithotripsy

INTRODUCTION

Urinary calculi are frequently encountered in urology. Traditionally, the lack of a perfect water injection and drainage system means the observation field is affected during ureteroscopy. Here, we explored the effect and clinical value of a new integrated suctioning semi-rigid ureteroscopic lithotripsy (URSL) for treating ureteral calculi.

MATERIAL AND METHODS

A total of 180 patients were successfully enrolled in this study (60 in each group). Group A included patients who underwent a traditional semi-rigid URSL, group B included patients who underwent a suctioning semi-rigid URSL with a sheath being connected to a vacuum device, and group C included patients who underwent a new type of suctioning integrated rigid URSL with a novel designed ureteroscope.

RESULTS

In total, 164 cases of URSL were completed in one stage. Compared with group A, group C had a higher stone-clearance rate at 30 days postoperatively, shorter operation time, and fewer hospitalization days (p < .05); compared with group B, group C had a higher one-stage operation success rate, shorter operation time, and fewer hospitalization days (p < .05).

CONCLUSIONS

Comparatively, the new suctioning integrated semi-rigid URSL is advantageous for treating upper urinary calculi, considering the reduced operation time, length of hospital stay, and low invasiveness.

Surgical outcomes of patients who underwent retrograde intrarenal surgery using a ureteral access sheath to manage kidney stones sized 1-2 cm compared between patients who did and did not undergo preoperative ureteral stenting

Objective

To investigate the surgical outcomes of patients who underwent retrograde intrarenal surgery (RIRS) using a ureteral access sheath (UAS) to manage kidney stones sized 1-2 cm compared between patients who did and did not undergo preoperative ureteral prestenting.

Materials and methods

This retrospective cohort study included 166 patients (aged ≥18 years) who underwent RIRS at Siriraj Hospital (Bangkok, Thailand) during February 2015-February 2020. All patients had renal calculi (stone size: 1-2 cm) located within the pelvicalyceal system. 80 and 86 patients were allocated to the prestent and non-prestent groups, respectively. Patient baseline characteristics, renal stone details, operative equipment, stone-free rate (SFR) at 2 weeks and 6 months, and perioperative complications were compared between groups.

Results

All patient baseline characteristics were similar between groups. At 2 weeks after surgery, the overall SFR was 65.1%, and the SFRs in the prestent and non-prestent groups were 73.4% and 59.5%, respectively (p = 0.09). At 6 months after surgery, the overall SFR was 80.1%, and the SFRs in the prestent and non-prestent groups were 90.7% and 79.3%, respectively (p = 0.08). The incidence of perioperative complications was not significantly different between groups.

Conclusions

There was no significant difference in the SFR between the presenting and non-prestenting groups at both the 2-week and 6-month postoperative time points. There was also no significant difference in intraoperative and postoperative complications between groups. The SFR was higher at 6 months than at 2 weeks in both groups with no additional procedure.

Microdamage analysis of single-use flexible ureteroscope immediately after lithotripsy use

This prospective ex vivo study investigated microdamage to single-use flexible ureteroscopes (fURS) after ureteroscopy and endoscopic combined intrarenal surgery (ECIRS). The performance of 30 WiScope devices (OTU Medical, San Jose, CA, USA) was examined immediately after use, dividing them into three equal groups: ureteroscopy and ECIRS in the prone and supine positions. The overall scope of microdamage assessment included the scope deflection, bending radius, resolution, and water flow rate. Additionally, we analyzed the association between scope status and surgical parameters. The deflection, bending radius, and resolution remained similarly above the thresholds in all groups. However, the water flow rate was below the threshold in seven scopes (70%) in the ureteroscopy group and none in the ECIRS groups (P = 0.001). Univariate and multivariable logistic regression analyses demonstrated that basket wire catheter use was associated with an increased risk for overall scope microdamage (odds ratio [OR], 22.70; P = 0.006 and OR, 22.40; P = 0.019, respectively). Stone size, total laser energy, and surgical position were not associated with a risk for scope microdamage. In conclusion, ureteroscopy was more closely associated with scope damage than ECIRS, and basket wire catheter use seemed to inflict more damage to the fURS.

Role of Pediatric Ureteral Access Sheath and Outcomes Related to Flexible Ureteroscopy and Laser Stone Fragmentation: A Systematic Review of Literature

Context

Flexible ureteroscopy and laser lithotripsy (FURSL) represent a good treatment option for pediatric urolithiasis. Scarce evidence is available about the safety and efficacy of the concomitant use of a ureteral access sheath (UAS) in the setting of pediatric ureteroscopy (URS).

Objective

To acquire all the available evidence on UAS usage in pediatric FURSL, focusing on intra- and postoperative complications and stone-free rates (SFRs).

Evidence acquisition

We performed a systematic literature research using PubMed/MEDLINE, Embase, and Scopus databases. The inclusion criteria were cohorts of pediatric patients <18 yr old, submitted to URS for FURSL, reporting on more than ten cases of UAS placement. The primary outcomes were prestenting rates, operating time, ureteric stent placement rates after surgery, rates and grades of complications, ureteral injuries, and overall SFR. A total of 22 articles were selected.

Evidence synthesis

In total, 26 intraoperative and 130 postoperative complications following URS with UAS placement were reported (1.8% and 9.18% of the overall procedures, respectively). According to the Clavien-Dindo classification, 32 were classified as Clavien I, 29 as Clavien II, 43 as Clavien I or II, six as Clavien III, and one as Clavien IV. Twenty-one cases of ureteral injuries (1.59%) were noted in the whole cohort; most of them were ureteral perforation or extravasation, and were treated with a temporary indwelling ureteric stent. The overall SFR after a single URS procedure was 76.92%; after at least a second procedure, it was 84.9%.

Conclusions

FURSL is a safe and effective treatment option for pediatric urolithiasis. UAS use was associated with a low rate of ureteric injuries, mostly treated and resolved with a temporary indwelling ureteric stent.

Patient summary

We performed a systematic literature research on the utilization of a UAS during ureteroscopy for stone treatment in pediatric patients. We assessed the outcomes related to the rates of intra- and postoperative complications and the rates of efficacy of the procedure in the clearance of stones. The evidence shows a low rate and grade of complications associated with UAS placement and good stone-free outcomes. A ureteric injury may occur in 1.6% of cases, but it is usually managed and resolved with a temporary indwelling ureteric stent.

Comparison of vacuum suction ureteroscopic laser lithotripsy and traditional ureteroscopic laser lithotripsy for impacted upper ureteral stones

PURPOSE

To compare a novel vacuum suction ureteroscopic laser lithotripsy (VS-URS) with traditional ureteroscopic laser lithotripsy (T-URS) for impacted upper ureteral stones and to better define the potential benefits of VS-URS.

METHODS

Between May 2019 and March 2021, 158 patients with impacted upper ureteral stones underwent ureteroscopic holmium-YAG laser lithotripsy. Of these, 76 underwent VS-URS and 82 underwent T-URS. In VS-URS procedures, the vacuum suction device is composed of a 5F ureteral catheter and a tee joint. The ureteral catheter is linked to the vacuum aspirator by the sidearm of the tee joint, and a 200 μm fiber is inserted through the tee joint and the ureteral catheter into the stone site for lithotripsy.

RESULTS

When compared to the T-URS group, the VS-URS group had a shorter mean operation time (38.18 ± 6.37 min vs. 46.65 ± 5.66 min; P = 0.000), lower fever rate (3.9% vs. 14.6%; P < 0.022), less stone retropulsion (5.3% vs. 18.3%; P = 0.012), lower extra management rate (6.58% vs. 21.95%; P = 0.006), and a higher stone-free rate of the first postoperative day (88.2% vs. 72.0%; P = 0.011). There were no significant differences in stone-free rates 1 month after surgery between groups (94.7% vs. 92.7%; P = 0.748).

CONCLUSIONS

VS-URS is an effective modality for impacted upper ureteral stones, and has a shorter operating time, lower fever rate, less stone retropulsion, and a higher primary stone-free rate compared with T-URS.

Pre- and peri-operative clinical information, physiological observations and outcome measures following flexible ureterorenoscopy (FURS), for the treatment of kidney stones. A single-centre observational clinical pilot-study in 51 patients

BACKGROUND

Kidney stone disease contributes to a significant proportion of routine urological practice and remains a common cause of worldwide morbidity. The main aim of this clinical-pilot study was to investigate the effect of flexible ureterorenoscopy (FURS) on pre- and peri-operative clinical information, physiological observations and outcome measures.

METHODS

Included were 51 patients (31 males, 20 females), who underwent elective FURS, for the treatment of kidney stones. Pre-operative and peri-operative clinical information, and post-operative physiological observations and outcome measures were collected using a standard case report form. Pre-operative clinical information included age, gender, BMI, previous history of stone formation and hypertension. Pre-operative stone information included the size (mm), Hounsfield units (HU), laterality and intra-renal anatomical location. Peri-operative surgical details included surgical time in minutes; Laser use; Duration and energy of laser; and post-operative stenting. The physiological outcomes measured included systolic and diastolic blood pressure (mmHg), Likert pain score, temperature, heart rate (bpm) and respiration rate (bpm). Following initial descriptive analysis, a series of Pearson's correlation coefficient tests were performed to investigate the relationship between surgical factors other variable factors.

RESULTS

A series of significant, positive correlations were observed between; age and surgical time (p = 0.014, r = 0.373); stone size and Hounsfield unit (p = 0.029, r = 0.406); surgical time and duration of laser (p < 0.001, r = 0.702); surgical time and BMI (p = 0.035, r = 0.322); baseline heart rate and Hounsfield unit (p = 0.026, r = - 0.414); base line heart rate and BMI (p = 0.030, r = 0.307).; heart rate at 120-min post FURS and age (p = 0.038, r = - 0.308); baseline pain score and BMI (p = 0.010, r = 0.361); baseline respiration rate and BMI (p = 0.037, r = 0.296); respiration rate at 240-min post FURS and BMI (p = 0.038, r = 0.329); respiration rate at 120 min post FURS and age (p = 0.022, r = - 0.330). Four patients developed post-operative complications (3-UTIs with urinary retention, 1-urosepsis).

CONCLUSIONS

We report that following FURS there is an association between various physiological, clinical and surgical parameters. Although these correlations are weak, they warrant further investigation as these may be linked with untoward complications, such as infection that can occur following FURS. This data, however, will need to be validated and reproduced in larger multi-centre studies.

Failure of ureteral access sheath insertion in primary flexible ureteroscopy for renal stones: is there any relation with inflammation?

PURPOSE

To investigate the relationship between failure to insert a ureteral access sheath (UAS) with inflammation and other clinical parameters in patients treated with flexible ureteroscopy for renal stones.

METHODS

This study included patients who underwent flexible ureteroscopy for the treatment of renal stones in our centre between 2015 and 2020. Patients who underwent any surgical procedure on the ipsilateral ureter and had a history of spontaneous stone passage were excluded. Patients were divided into two groups based on UAS insertion success (group 1) or failure (group 2). Both groups were compared with a view to clinical characteristics, preoperative neutrophil, lymphocyte, monocyte and platelet counts and ratios of these counts, all being considered inflammatory markers. A multivariate logistic regression analysis was performed to determine the independent variables affecting UAS insertion success.

RESULTS

There were 113 (59.1%) patients in group 1, while group 2 consisted of 78 (40.9%) patients. The rates of male gender, coronary artery disease and preoperative ipsilateral hydronephrosis were significantly higher in group 2, while platelet counts and platelet-lymphocyte ratios were significantly lower. Our analysis revealed four independent predictors for UAS insertion failure: female gender (odds ratio [OR]=2.1) increased the rate of UAS insertion success, while hydronephrosis (OR=1.6), low platelet counts and PLR increased the rate of UAS insertion failure (OR=0.99, OR=0.98, respectively).

CONCLUSION

Our results suggest that male gender and ipsilateral hydronephrosis are associated with increased UAS insertion failure. Although we found a relationship between relatively low platelet levels and UAS insertion failure, we think that further studies are needed to investigate this matter.

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.

Ureteroscopy with thulium fiber laser lithotripsy results in shorter operating times and large cost savings

PURPOSE

Prolonged ureteroscopy (URS) is associated with complications including ureteral perforation, stricture, and urosepsis. As laser lithotripsy is one of the most common urologic procedures, small cost savings per case can have a large financial impact. This retrospective study was designed to determine if Thulium fiber laser (TFL) lithotripsy decreases operative time and costs compared to standard Holmium:YAG (Ho:YAG) lithotripsy without pulse modulation.

METHODS

A retrospective review of URS with laser lithotripsy was conducted for 152 cases performed from August 2020 to January 2021. Variables including cumulative stone size, location, chemical composition, prior ureteral stenting, and ureteral access sheath use were recorded for each case. A cost benefit analysis was performed to show projected cost savings due to potentially decreased operative times.

RESULTS

Compared to Ho:YAG, use of TFL resulted in an average decrease of 12.9 min per case (p = .021, 95% CI [2.03-23.85]). In subgroup analysis of cases with cumulative stone diameter less than 15 mm, the difference was 14.0 min (p = .007, CI [3.95-23.95]). For cases less than 10 mm, the mean difference was 17.3 min in favor of TFL (p = .002, 95% CI [6.89-27.62]). This ~ 13 min reduction in operative time resulted in saving $440/case in direct operating room costs giving our institution a range of $294,000 to $381,900 savings per year.

CONCLUSIONS

TFL has a significantly shorter operative time and decreased cost when compared to the standard Ho:YAG for equivalent kidney stone and patient characteristics. Longer term follow up is needed to see if recurrence rates are affected.

Outcomes of flexible uretrorenoscopy for solitary renal stones up to 15 mm, hits and misses: A single-surgeon experience

Abstract:

Introduction: In this study, we retrospectively evaluated the outcomes of flexible uretrorenoscopy (fURS) for removal of solitary renal stones sized up to 15 mm.

Material and Methods:

We evaluated the data of 115 patients who underwent fURS at our unit between Jan 2018 and Dec 2019. All fURS were performed by a single surgeon using Flex-2 flexiscope. Ureteral Access sheath (UAS) of size 9/11 fr was used in all patients. Stones were fragmented using 20 watts laser. Few fragments were retrieved using Nitinol zero tip basket for assessment of the passability of remaining dust and sent for stone analysis. Data pertaining to demographic characteristics, stone size, stone site, operative time, intra and post operative complications were retrieved from the records.

Results:

Of the 115 patients who underwent fURS, 71 (61.7%) were male and 44 (38.2%) were female. Average age of patients was 32.9±8.9 years; the average body mass index was 22.9±3.9 kg/m2. Average size of the stone was 11.0±1.5 × 10.2±1.3 mm. The stone free rates at the end of 3 weeks and 3 months were 97% and 99%, respectively.

Conclusion:

fURS is an effective minimally-invasive procedure for removal of single stones up to 15 mm in size. We observed minimal morbidity rates and acceptable stone free rates in our series.

Evaluating predictive factor of Systemic Inflammatory Response Syndrome and Postoperative Pain in Patients Without Ureteral Stent Placement After Ureteral Access Sheath Use in Flexible Ureteroscopy for Stone Management

BACKGROUND AND OBJECTIVE

This retrospective cohort study aimed to evaluate the safety of stentless flexible ureteroscopy (fURS) using a ureteral access sheath (UAS) for stone management.

PATIENTS AND METHODS

A total of 270 ureteral stentless postoperative patients were analyzed. Stentless indication was characterized by having no ureteral wall or mucosa injury with only slight erosion, < 1-hour operative time, and no endoscopic stone fragments with or without stone dust. Postoperative complications and pain were analyzed for safety measurements. In addition, preoperative and intraoperative risk factors associated with the incidence of systemic inflammatory response syndrome (SIRS) and postoperative pain were evaluated.

RESULTS

The most common UAS sizes were 10/12 Fr (69.6%) and 9.5/11.5 Fr (28.1%). The rate of patients who were stone-free was 95.9%. The median operation time was 34 min. Only three grade 1 ureteral injuries occurred intraoperatively. Postoperative SIRS occurred in 8.8% of patients, and postoperative use of analgesics was 35.9%. Only four patients were required to undergo eventual ureteral stenting. Less than 10/12-Fr UAS was the only factor positively associated with preventing postoperative SIRS (odds ratio [OR], 4.733; 95% confidence interval [CI], 1.085-20.644). Older age and preoperative ureteral stenting were positively associated with preventing postoperative pain (OR, 0.970; 95% CI, 0.951-0.990 and OR, 0.427; 95% CI, 0.232-0.786; respectively).

CONCLUSION

Stentless fURS with UAS in stone management was feasible for selected patients. UAS size of < 10/12 Fr, older age, and preoperative stenting are possible keystones to achieving stentless fURS with UAS postoperatively.

Understanding Ureteral Access Sheath Use Within a Statewide Collaborative and Its Effect on Surgical and Clinical Outcomes

Introduction: Ureteral access sheaths (UASs) are frequently used during ureteroscopy (URS), but their use is not without potential risk. We investigated patterns of UAS use and associated outcomes across practices in Michigan within a quality improvement collaborative. Methods: The Michigan Urological Surgery Improvement Collaborative (MUSIC) Reducing Operative Complications from Kidney Stones (ROCKS) initiative maintains a web-based, prospective clinical registry of patients undergoing URS for urinary stone disease (USD). We analyzed all patients undergoing primary URS for renal and ureteral stones from June 2016 to July 2018 in the ROCKS registry. We determined rates of UAS usage across practices and associated outcomes, including 30-day emergency department (ED) visits and hospitalization, as well as stone-free rates. Using multivariate logistical regression, we determined the predictors of UAS use as well as outcomes, including stone-free rates, ED visits, and hospitalizations, associated with UAS use. Results: Of the 5316 URS procedures identified, UASs were used in 1969 (37.7%) cases. Stones were significantly larger and more likely to be located in the kidney in cases with UAS use. UAS use during URS varied greatly across practices (1.9%-96%, p < 0.05). After adjusting for clinical and surgical risk factors, UAS use significantly increased the odds of postoperative ED visits (odds ratio [OR] = 1.50, 95% confidence interval [CI] 1.17-1.93, p < 0.05) and hospitalization (OR = 1.77, 95% CI 1.22-2.56, p < 0.05) as well as decreased the odds of being stone free (OR = 0.75, 95% CI 0.57-0.99, p < 0.05). Conclusions: In the current study, UAS use during URS for USD was not associated with an increased likelihood of being stone free; moreover, it increased the odds of a postoperative ED visit and or hospitalization. Our findings demonstrate that UAS use is not without risk and should be employed judiciously.

Etiology and Ureteral Reconstruction Strategy for Iatrogenic Ureteral Injuries: A Retrospective Single-Center Experience

OBJECTIVE

To analyze the etiology, characteristics, and ureteral reconstruction strategies of iatrogenic ureteric injuries in a high-volume center.

METHODS

Between September 2010 and August 2019, we retrospectively collected patients who underwent ureteral reconstruction due to iatrogenic ureteric injuries. Patient profiles, laboratory data, imaging studies, perioperative data, and complications were recorded.

RESULTS

Sixty-eight patients were enrolled in this study. The upper, middle, and lower thirds of the ureter were affected in 30, 2, and 36 cases, respectively. Of the 68 ureteric injuries, 69.1% occurred during urological procedures, followed by gynecological procedures, general surgery, radiotherapy, and orthopedic surgery. The majority of urological injuries (41, 87.2%) occurred due to stone removal. There was a significant difference in the age, sex, and location of ureteric injuries between the urological and nonurological groups. The median follow-up time was 17.9 months. The overall symptom remission rate was 91.2% and ranged from 87.5 to 100% for different reconstructive surgeries.

CONCLUSIONS

Urological procedures were the most common cause of iatrogenic ureteric injury; thus, extra care should be taken. Timely detection and appropriate treatment of the ureteric injuries are necessary. Treatment strategies should be depended on the location and length of injury.

Impact of ureteral access sheath on renal stone treatment: prospective comparative non-randomised outcomes over a 7-year period

PURPOSE

To compare the outcomes (stone free rate and complications) of renal stone treatment with and without the use of ureteral access sheath (UAS). The worldwide use of UAS has risen over the last decade; however, questions still remain on the safety and outcomes with its use. We wanted to look at the role of UAS for treatment of consecutive renal stones over a 7-year period.

METHODS

The outcomes of flexible ureteroscopy and stone treatment (FURS) for renal stones with and without the use of UAS was prospectively compared from March 2012 to July 2018. Patients were divided into two groups: group-1 where UAS was used for stone treatment and group-2 where a UAS was not used. Data were collected prospectively on consecutive patients for demographics, stone size, location and number, pre and post-operative stent usage, operative time duration, stone free rate (SFR), length of stay and complications.

RESULTS

During the study period, 338 patients underwent FURS for renal stones, of which a UAS was used for 203 (60%) patients. The mean age of patients was 56 years (range 2-89 years) with a male:female ratio of 204:134. The mean cumulative stone size and the mean number of stones was 16.5 ± 10.8 mm and 11.37 ± 8.08 mm (P < 0.001), and 2.17 ± 1.99 and 1.66 ± 1.50 (P = 0.009) for groups 1 and 2 respectively. The pre and post-operative stent insertion rates were similar in the two groups. The procedural time was longer in group-1 (54.8 ± 25.8 min) compared to group-2 (41.3 ± 22.2 min) (P < 0.001). The SFR for group-1 (88%) was slightly lower than group-2 (94%) although this was not statistically significant (P = 0.07). There were no intra-operative complications in either of the groups. Post-operative complications were seen in eight patients in group-1 (7 Clavien I/II and 1 Clavien IVa) and two patients in group-2 (Clavien I) (P = 0.19).

CONCLUSION

The use of UAS for renal stones is safe with no intra-operative complications noted in our series. Good stone-free rates were obtained for large and multiple renal stones with a small risk of minor complications post-operatively.

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.

Dusting, fragmenting, popcorning or dustmenting?

PURPOSE OF REVIEW

The present review identifies the latest scientific investigations within the fields of fragmenting and dusting to discuss optimizing treatment. In addition, new settings such as 'popcorning' are scrutinized carefully.

RECENT FINDINGS

During the past years, endoscopic techniques have continuously developed and changed the management of the treatment of kidney stones using ureteroscopy (URS). The most currently used energy source for stone disintegration is holmium laser lithotripsy. This technique offers different options for the surgeons to treat their patients suffering from kidney stones.

SUMMARY

URS with the holmium laser allows surgeons to use a variety of different strategies for treating urinary stones. There are two techniques which are most frequently used within this field: firstly fragmenting, using low frequencies and high pulse energy to break stones into small fragments before removal. On the other hand, dusting has been popularized in the field of endourology in recent years. This uses high frequencies and low pulse energy to form fine dust particles which then pass spontaneously down the ureter.

Handling and protecting your flexible ureteroscope: how to maximise scope usage

Flexible ureteroscopy is an important therapeutic and diagnostic procedure and has seen rapid rise in its utilisation in recent years. There have been numerous developments in flexible ureteroscope (fURS) technology but scope fragility, and the associated high maintenance costs, remains a concern. A comprehensive Medline search for related publications from the last 20 years was undertaken to identify common causes of fURS damage and ascertain practices to minimise this. Flexible ureteroscopy can be due to intraoperative causes (loss of the deflection mechanism, damage to the working channel due and fibreoptic bundle injury) and non-operative damage which occur during cleaning, sterilisation and handling of the fURS. The review summarises the available literature to help highlight common mechanisms of scope damage, and outlines evidence-based measures to reduce the risk of damage and maximise durability. Scope fragility remains a problem with significant associated cost implications. In a culture of rising fURS use and reducing re-imbursement for endourologists, prolonging the longevity of the fURS is imperative for maintaining profitability. There are simple and inexpensive practices which can be immediately adopted to maximise fURS use and reduce the need for repairs.

Is it safe to use a ureteral access sheath in an unstented ureter?

Background

The aim of this study was to examine ureteral stricture rate after the use of UAS in an unstented ureter and compare complications of smaller vs. larger-caliber UAS.

Methods

We conducted a retrospective analysis of consecutive RIRS for renal stones, with the use of UAS in unstented ureters. We excluded cases with previous ureteroscopies, who carried ureteral stent or nephrostomy, had impacted stones, underwent radiation treatment, or had urinary tract malignancies. The primary outcome was formation of ureteral strictures diagnosed by hydronephrosis in ultrasound test and late secretion in dynamic renal scan. Secondary outcome was stone-free-rate (SFR) and complications. In addition, we compared safety and efficacy of smaller (9.5/11.5Fr) vs. larger-caliber (12/14Fr) UAS.

Results

The cohort included 165 patients with a median follow-up time of 115 days. There was no case of ureteral stricture formation after the use us UAS, despite using a larger-caliber UAS in nearly half the cases. Larger-caliber UAS was not associated with more complications compared to the smaller-caliber one (p = 0.780). SFR was non-significantly higher in the larger-caliber UAS group (p = 0.056), despite having a larger stone burden, and only stone number was associated with SFR (p = 0.003).

Conclusions

These data suggest that the use of UAS during RIRS in an unstented ureter is safe and does not involve ureteral stricture formation after one procedure. Furthermore, the use of wider sheaths was not found to be associated with higher complications rate.

The Morbidity of Ureteral Strictures in Patients with Prior Ureteroscopic Stone Surgery: Multi-Institutional Outcomes

PURPOSE

Nephrolithiasis is an increasingly common ailment in the United States. Ureteroscopic management has supplanted shockwave lithotripsy as the most common treatment of upper tract stone disease. Ureteral stricture is a rare but serious complication of stone disease and its management. The impact of new technologies and more widespread ureteroscopic management on stricture rates is unknown. We describe our experience in managing strictures incurred following ureteroscopy for upper tract stone disease.

MATERIALS AND METHODS

Records for patients managed at four tertiary care centers between December 2006 and October 2015 with the diagnosis of ureteral stricture following ureteroscopy for upper tract stone disease were retrospectively reviewed. Study outcomes included number and type (endoscopic, reconstructive, or nephrectomy) of procedures required to manage stricture.

RESULTS

Thirty-eight patients with 40 ureteral strictures following URS for upper tract stone disease were identified. Thirty-five percent of patients had hydronephrosis or known stone impaction at the time of initial URS, and 20% of cases had known ureteral perforation at the time of initial URS. After stricture diagnosis, the mean number of procedures requiring sedation or general anesthesia performed for stricture management was 3.3 ± 1.8 (range 1-10). Eleven strictures (27.5%) were successfully managed with endoscopic techniques alone, 37.5% underwent reconstruction, 10% had a chronic stent/nephrostomy, and 10 (25%) required nephrectomy.

CONCLUSIONS

The surgical morbidity of ureteral strictures incurred following ureteroscopy for stone disease can be severe, with a low success rate of endoscopic management and a high procedural burden that may lead to nephrectomy. Further studies that assess specific technical risk factors for ureteral stricture following URS are needed.

A Prospective Study Analyzing the Association Between High-grade Ureteral Access Sheath Injuries and the Formation of Ureteral Strictures

OBJECTIVE

To assess the intermediate- and long-term effect of high-grade ureteral injuries from ureteral access sheaths.

METHODS

Patients undergoing ureteroscopy for upper tract calculi were prospectively enrolled at 2 sites from 2010 to 2015. A 12/14 French sheath was used and the ureter was inspected with a flexible ureteroscope during withdrawal of the sheath and recorded. The videos were then evaluated by 2 blinded endourologists, and any injuries were graded per the Traxer ureteral injury scale. Only high-grade injuries were included. The primary endpoint was defined as ongoing hydronephrosis without an obstructing stone on follow-up imaging indicating a ureteral stricture. Logistic regression analysis was used to assess the relationship between hydronephrosis, ureteral injury, and other patient variables.

RESULTS

Fifty-six patients were identified with high-grade ureteral injuries. Sixteen patients (28.6%) were female. Median age was 56.4 years (range 14-85). Median follow-up was 35.8 months (range 0-88). Three patients (5.5%) had hydronephrosis on follow-up imaging, only 1 of whom developed a de novo ureteral stricture. On univariate analysis, hydronephrosis was associated with a shorter stent duration (P = .11) and older age (P = .17).

CONCLUSION

Endoscopically identified high-grade ureteral lesions following ureteral access sheath placement do not lead to clinically significant sequelae on intermediate term follow-up, with a stricture rate comparable to those without visible injuries of 1.8%.

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.

Use of a modified ureteral access sheath in semi-rigid ureteroscopy to treat large upper ureteral stones is associated with high stone free rates

Objective

To examine differences in outcomes of semi-rigid ureteroscopy (URS) with or without a modified-ureteral-access-sheath (mUAS) to treat large upper ureteral stones.

Methods

Patients with single, radio-opaque large upper ureteral stone (≥10 mm) treated using semi-rigid URS between August 2013 and October 2016 were retrospectively evaluated. The stone-free status was determined from Kidney-ureter-bladder (KUB) X-ray films taken on postoperative Day 1 and after 1 month.

Results

Of 103 patients meeting inclusion criteria, 43 (41.75%) and 60 (58.25%) were treated with semi-rigid URS with and without mUAS, respectively. The immediate stone-free rate (SFR) for the mUAS group was significantly higher than the non-mUAS group (40 [93.0%] vs. 46 [76.7%]; p = 0.033). The SFR at 1 month was also high for patients treated using mUAS, but not statistically different from patients not treated with mUAS (41 [95.3%] mUAS vs. 51 [85.0%] non-mUAS; p = 0.115). Auxiliary procedure rates were significantly lower for mUAS patients compared to non-mUAS patients (2 [4.7%] vs. 14 [23.3%]; p = 0.01). There were no significant differences in surgical duration and hospital stays, and the overall complication rates were statistically similar for mUAS patients compared to non-mUAS patients (1 [2.3%] vs. 3 [5.0%]; p = 0.638).

Conclusion

Application of mUAS to treat large upper ureteric stones was associated with higher immediate SFR and final SFR, and lower auxiliary procedure rates relative to patients treated without use of mUAS. Moreover, the use of mUAS did not lengthen operation duration or hospital stays.

Updates in endourological management of urolithiasis

Urinary stone disease, or urolithiasis, is a very common disease with increasing prevalence and incidence. With the advancement of endoscopic techniques, the treatment outcomes of ureteroscopy (or transureteral lithotripsy) and percutaneous nephrolithotomy are continuously improving. In recent years, there have been many new developments in the field, including new endoscopy design, more effective auxiliary tools, improvement in treatment protocols, introduction of robotic technology, combining both ureteroscopy and percutaneous nephrolithotomy (endoscopic combined intrarenal surgery or transureteral lithotripsy-assisted percutaneous nephrolithotomy), improvement in laser technology, and so on. All these new inputs will further improve the treatment efficacy and safety of the procedures, thus benefiting our patients. In the present review, we briefly go through the main steps of ureteroscopy and percutaneous nephrolithotomy, with a concise description and application of these new advances.

Unplanned 30-Day Encounters After Ureterorenoscopy for Urolithiasis

OBJECTIVE

To identify avoidable predictors of postureteroscopy (URS) unplanned encounters and to minimize 30-day encounters.

MATERIALS AND METHODS

We performed retrospective chart review and telephone surveys on patients who underwent URS for urolithiasis between January and June 2016. Univariate and multivariable analyses evaluated for potential predictors of unplanned encounters.

RESULTS

Of 157 patients, there were 44 (28.0%) unplanned patient-initiated clinical phone calls, 23 (14.6%) emergency department (ED) visits, and 8 (5.1%) readmissions, with pain being the most common complaint during the encounters. Factors associated with a higher rate of phone calls include first-time stone procedure (36.6% vs 20.9%, p = 0.029), outpatient status (30.3% vs 0%, p = 0.021), intraoperative stent placement (31.2% vs 0%, p = 0.006), and stent removal at home (58.8% vs 28.8%, p = 0.014). Factors associated with increased rate of ED visits were first-time stone procedure (22.5% vs 8.1%, p = 0.011) and ureteral access sheath (UAS) usage (29.6% vs 11.8%, p = 0.018). Factors associated with a higher rate of readmissions were lower body mass index (23.9 vs 29.7, p = 0.013), bilateral procedure (20.0% vs 2.9%, p = 0.010), and UAS usage (14.8% vs 3.1%, p = 0.032). Stone burden, operative time, Charlson comorbidity index, and preoperative urinary tract infection were not significantly associated with postoperative encounters.

CONCLUSIONS

Pain, first-time stone treatment, presence of a ureteral stent, outpatient status, bilateral procedures, and UAS usage were common reasons for postoperative encounters after URS. Appropriate perioperative patient education and counseling and adequate pain management may minimize these encounters and improve treatment quality and patient satisfaction.

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.

Flexible ureteroscopic holmium laser lithotripsy with PolyScope for senile patients with renal calculi

The present study reported the clinical experience of using a PolyScope with holmium laser lithotripter in managing renal calculi in senile patients. Between December 2013 and December 2016, 157 senile patients (69.1±6.1 years old) were treated with PolyScope holmium laser lithotripsy for renal calculi at Xin Hua Hospital (Shanghai, China). The mean stone digitized surface area was 154.2±57.7 mm² (range, 55.8–478.3 mm²). A thorough medical history investigation, and laboratory and radiological examination were followed by proper preoperative management. The PolyScope was then passed into the renal cavities following the position of the ureteral access sheath, with laser energy maintained at 1.0–2.0 J, frequency 10–15 Hz. The demographical and operative information of senile patients were compared with that of the 332 non-senile patients operated at the same period time. The average operative time was 54.6±13.2 min (range, 37–124 min). No major complications, including ureteral perforation or sepsis were encountered. The single session stone-free rate (SFR) was 81.5% and the overall SFR was 89.2%, similar to that of the non-senile group. PolyScope combined with holmium laser lithotripter is safe and effective in managing renal calculi in senile patients compared with non-senile patients, with considerately high SFRs and low complication rates.

Retrograde intrarenal surgery: An expanding role in treatment of urolithiasis

During the past 3 decades, the surgical management of kidney stones has undergone many technological advances and one is the development of the flexible ureteroscopy. The development of this instrument as well as ancillary equipment such as baskets, graspers, and others, and improvements in lithotripsy with Holmium: YAG laser have led to expand its indications with diagnostic and therapeutic management of medical issues of the upper urinary tract such as urolithiasis and urothelial tumors. The objective of this review is to describe its indications and results in the different scenarios for the treatment of urinary stones.

Does ureteral access sheat usage lead to permanent damage in the ureter? A placebo controlled trial in a rabbit model

PURPOSE

To evaluate the clinical stenosis or precursor histological changes that ureteral access sheaths commonly used in ureteroscopic surgeries may cause in the long term in ureter.

METHODS

In this study, the animals were divided into 9 groups and according to their groups, ureters of the rabbits were endoscopically fitted with 2F and 3F ureter catheters. The catheters were left in place and withdrawn after a specified period of time. All the ureters were excised and evaluated macroscopically, microscopically and histologically. Ureter diameters were measured and FGF-2 (+) labeled fibroblasts were counted in connective tissue as stenosis precursors.

RESULTS

Macroscopically or microscopically, no stenosis was found in any group. The ureter diameter of the group that were catheterized for the longest time with the catheter that had the widest diameter was significantly lower than the group with the shorter duration and the catheter with the narrower diameter and the control group. When the groups were compared in terms of their FGF values, there was a significant difference in FGF-2 counts at all three ureter levels (p <0.05).

CONCLUSION

The use of ureteral access sheath may lead to histological changes, as its diameter and duration increase.

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.

Use of the ureteral access sheath during ureteroscopy: A systematic review and meta-analysis

The debate still rages on for the usefulness of ureteral access sheath (UAS). Therefore, a meta-analysis to discuss the effects of applying UAS during ureteroscopy was performed. The protocol for the review is available on PROSPERO (CRD42017052327). A literature search was conducted up to November, 2017 using the Web of science, PUBMED, EMBASE and Cochrane Library. The quality of articles was assessed by the Jadad scale and Newcastle Ottawa Scale (NOS). Egger’s test and the trim-and-fill method were used to evaluate publication bias. Effect sizes were calculated by pooled odds ratio (ORs) and mean differences (MDs). Sensitivity analyses and subgroup analyses were performed to explore the origin of heterogeneity. Eight trials with a total of 3099 patients and 3127 procedures were identified. Results showed no significant difference in stone-free rate (SFR) (OR = 0.83, 95% CI 0.52–1.33, P = 0.45), intraoperative complications (OR = 1.16, 95% CI 0.81–7.69, P = 0.88), operative time (MD = 4.09, 95% CI -15.08–23.26, P = 0.68) and hospitalization duration (MD = -0.13, 95% CI -0.32–0.06, P = 0.18). However, the incidence of postoperative complications was higher in UAS group (OR = 1.46, 95% CI 1.06–2.00, P = 0.02). Evidence from meta-analysis indicated that the use of UAS during ureteroscopy did not manifest advantages. However, given the intrinsic restrictions of the quality of selected articles, more randomized controlled trials (RCTs) are warranted to update the findings of this analysis.

Is retrograde intrarenal surgery the game changer in the management of upper tract calculi? A single-center single-surgeon experience of 131 cases

Introduction:

Success of any modality for stone disease needs to be evaluated in terms of Stone Free Rates (SFR), auxiliary procedures needed; complications and follow up. SFR in RIRS is subject to parameters like stone burden, location, number, hardness, composition; calyceal and ureter anatomy; use of ureteric access sheath (UAS); surgeon experience etc.

Methods:

The aim of this study is to evaluate the efficacy and safety of RIRS for managing upper tract stones. The objectives include evaluating SFR in RIRS in relation to stone burden, location and number. Other objectives include evaluating SFR after re RIRS in relation to stone burden, necessity of pre DJ stenting, use of UAS and post operative complication rate. 131 patients operated by single surgeon for single/multiple renal and/or upper ureteric stones were evaluated. Stone size > 3 mm on follow up CT KUB was considered as residual. Re RIRS was required for residual stones.

Results:

The overall SFR was 76%. SFR were statistically lower with stone burden > 1.5 cm, lower calyceal stones and single stones with stone burden > 1.5 cm. SFR was 90% after 2^nd RIRS and 98.5% after 3^rd RIRS procedure. No significant difference in SFR was noted between single v/s multiple stones, single calyx v/s multiple calyx stones and renal v/s upper ureteric stones. No major complication was noted.

Conclusion:

Larger stone burden and lower calyceal location are important factors deciding SFR in RIRS. With auxiliary procedure, RIRS is safe and effective compared to PCNL.

Micro-Costing Analysis Demonstrates Comparable Costs for LithoVue Compared to Reusable Flexible Fiberoptic Ureteroscopes

INTRODUCTION

Reusable ureteroscope durability and need for repair are significant sources of expense and inefficiency for patients and urologists. Utilization of LithoVue™, a disposable flexible digital ureteroscope, may address some of these concerns. To identify its economic impact on clinical care, we performed a micro-cost comparison between flexible reusable fiberoptic ureteroscopes (URF-P6™) and LithoVue.

PATIENTS AND METHODS

For this prospective, single-center micro-costing study, all consecutive ureteroscopies performed during 1 week each in July and August 2016 utilized either URF-P6 or LithoVue ureteroscopes respectively. Workflow data were collected, including intraoperative events, postoperative reprocessing cycle timing, consumables usage, and ureteroscope cost data.

RESULTS

Intraoperative data analysis showed mean total operating room time for URF-P6 and LithoVue cases were 93.4 ± 32.3 and 73.6 ± 17.4 minutes, respectively (p = 0.093). Mean cost of operating room usage per case was calculated at $1618.72 ± 441.39 for URF-P6 and $1348.64 ± 237.40 for LithoVue based on institutional cost rates exclusive of disposables. Postoperative data analysis revealed costs of $107.27 for labor and consumables during reprocessing for URF-P6 cases. The costs of ureteroscope repair and capital acquisition for each URF-P6 case were $957.71 and $116.02, respectively. The total ureteroscope cost per case for URF-P6 and LithoVue were $2799.72 and $2852.29, respectively.

CONCLUSIONS

Micro-cost analysis revealed that the cost of LithoVue acquisition is higher per case compared to reusable fiberoptic ureteroscopes, but savings are realized in labor, consumables, and repair. When accounting for these factors, the total cost per case utilizing these two ureteroscopes were comparable.

Identifying factors associated with need for flexible ureteroscope repair: a Western Endourology STone (WEST) research consortium prospective cohort study

Maintenance of flexible ureteroscopes can involve high costs and administrative burden. Instrument fragility necessitates eventual repair, rendering scopes inaccessible during refurbishment. We conducted a multi-institutional prospective cohort study to identify perioperative factors influencing flexible ureteroscope durability. Patients undergoing flexible ureteroscopy (URS) at six United States endourology centers were enrolled between August 2014 and June 2015. Surgeon self-reported concern and satisfaction with scope performance as well as upward and downward angles of deflection for each scope tip were measured before and after each procedure. The need for scope repair was determined by the operating surgeon at the time of the procedure and recorded. 424 URS cases using 74 flexible ureteroscopes were identified. Scope repair was required in 28 cases (6.6%) involving 26 scopes (35.1%). Upon univariate analysis, shorter patient height, absence of guidewire use, presence of a ureteral access sheath (UAS), longer procedure time, larger stone size, lithotrite type, surgeon training level, and self-reported concern were associated with scope repair. Upon multivariate analysis, UAS use (OR = 2.53, p = 0.005) and degree loss of scope upward flexion during a case (OR = 1.02, p = 0.03) increased the odds of a scope needing repair while the use of safety guidewire decreased the odds of a scope repair (OR = 0.50, p = 0.045). Lithotrite use and surgeon concern were associated with degree loss of scope upward flexion. The use of a UAS, absence of a safety guidewire, and the loss of upward ureteroscope flexion should be considered when evaluating means of optimizing reusable ureteroscope durability.

Flexible ureteroscopy: technique, tips and tricks

During the last decades, the surgical management of kidney stones benefited of many technological advances and one of them is the development of flexible ureteroscopy (fURS). This tool, ancillary equipment such as graspers and baskets, and lithotripsy technique with Holmium:YAG laser underwent many improvements leading to a widening of its indications with diagnostic and therapeutic management of upper urinary tract pathologies such as urolithiasis and urothelial tumors. The objective of this review is to describe the surgical technique for fURS as well as tips and tricks for the treatment of renal stones.

"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.

Prevention strategies for ureteral stricture following ureteroscopic lithotripsy

Ureteral stricture formation after ureteroscopic lithotripsy is a late complication that can lead to hydronephrosis and a subsequent risk of renal deterioration. The specific incidence is unknown, and the mechanism of stricture formation has not been completely explained. In this review, we summarize the current evidence regarding the incidence of this condition and discuss its pathogenesis. We then list preventive strategies to reduce the morbidity of ureteral strictures.

[Safety and feasibility of outpatient flexible ureteroscopy for urinary stones: A retrospective single-center study]

AIM

Management of urolithiasis has changed over the past decades. Outpatient surgery has become a major issue for healthcare systems. The aim of this study was to assess the feasibility of outpatient flexible ureteroscopy.

METHODS

A single-center retrospective study has been conducted including all patients who underwent an outpatient flexible ureteroscopy between January 2012 and December 2013. Failure of outpatient management was defined as length of hospital stay>12 hours or readmission within 48 hours after discharge. Univariate analysis was performed to seek for predictors of failure of outpatient management.

RESULTS

One hundred and fifty-seven patients who underwent a total of 174 procedures were included. They were mostly men (57.5 %), with a mean body mass index of 25.2kg/m² (±4.3). The stones were mostly unique (64.3 %), with a mean size of 14.2mm (±11.2). Eighty patients had a double J stent preoperatively (46.5 %), and mean operative time was 64.2 minutes (±34.1). An ureteral access sheath was used in 39 procedures (22.4 %). A double J stent was left postoperatively in 103 patients (59.1 %). In total, 165 procedures (94.8 %) were performed successfully as outpatient surgery. On postoperative imaging, the stone-free rate was 69.5 %. Postoperative complications occurred in 3.4 % of cases and were mostly minor (i.e. Clavien 1-2; 83.3 %). Predictive factors of failed outpatient management were male gender (P=0.04), BMI (P=0.03), and anticoagulants intake (P=0.003).

CONCLUSION

Outpatient flexible ureteroscopy for urinary stones is feasible and its low failure and complications rate may allow a wider spread of its use.

LEVEL OF EVIDENCE

4.

Ureteral Access Sheath Influence on the Ureteral Wall Evaluated by Cyclooxygenase-2 and Tumor Necrosis Factor-α in a Porcine Model

Objective: To examine the effect of ureteral access sheath (UAS) on the expression of the pro-inflammatory mediators cyclooxygenase-2 (COX-2) and tumor necrosis factor-α (TNF-α) in the ureteral wall.

Material and Methods: In 22 pigs an UAS was inserted and removed after 2 minutes on one side and 2 hours on the contralateral side. Postoperatively ureters were excised in vivo, and tissue samples from the distal (2 minutes/2 hours) and proximal ureter (2 minutes/2 hours) were snap-frozen before quantitative polymerase chain reaction analysis of COX-2 and TNF-α. Five unmanipulated ureteral units from other pigs served as the control group.

Results: Compared to controls COX-2 mRNA was significantly upregulated in all UAS treated ureteral groups. Similarly, TNF-α mRNA was upregulated in all groups except the 2-minute proximal ureteral group. Both COX-2 and TNF-α expression were significantly higher in the distal than in the proximal ureter in the UAS treated ureters. After UAS insertion for 2 minutes, expression levels in the distal ureter were increased 6.5- and 8-fold for COX-2 and TNF-α, respectively; and after 2 hours of UAS placement COX-2 and TNF-α mRNA expression levels were increased 9- and 9.5-fold, respectively.

Conclusion: The pro-inflammatory mediators COX-2 and TNF-α were significantly upregulated in the ureteral wall by the influence of UAS. These findings may have implications for postoperative pain, drainage, and complications.