Ureteral access strategies: pro-access sheath

Ureteroscopic lithotripsy with pressure-measuring ureteral access sheath for large ureteral stones

INTRODUCTION

To evaluate the safety and efficacy of ureteroscopic lithotripsy with pressure-measuring ureteral access sheath (PM-UAS) for large ureteral stones.

MATERIAL AND METHODS

A total of 258 consecutive patients with large ureteral stones ≥15 mm was enrolled. They were treated by ureteroscopic lithotripsy with PM-UAS in the oblique supine lithotomy position. The technology can precisely monitor and automatically control cavity pressure. The cavity pressure control value was set at -15 mmHg∼-5 mmHg. The cavity pressure limit value was set at 30 mmHg. Infusion flow rate was set at 100-200 ml/min. Postoperative data such as stone-free rate and complications were analyzed.

RESULTS

PM-UAS was successfully implanted in 225 patients at one stage. Eighteen cases of patients who had failed the first surgery were successfully treated with a second operation. Fifty-one cases with stones migrating up to the kidney were converted to flexible lithotripsy. The other 15 cases were converted to percutaneous nephrolithotomy due to significant ureteral stenosis. The operative time was 49.5 ± 11.2 min. The stone-free rates after one month and three months were 87.2% (212/243) and 94.2% (229/243), respectively. Complications from grade I to II were observed in 25(10.3%) patients. No other complications from grade III to V were noted.

CONCLUSION

The ureteroscopic lithotripsy with PM-UAS is safe and efficacious for large ureteral stones.

The outcomes of flexible ureteroscopy for renal calculi of 2 cm or more with and without the use of ureteral access sheath: A retrospective study

INTRODUCTION

The rate of success of retrograde intrarenal surgery (RIRS) for treating urinary tract stones is high, and the procedure is growing in popularity. The routine use of ureteral access sheath (UAS) remains somewhat controversial. The aim of this study was to assess the efficacy and safety of employing UAS during flexible ureteroscopy for treating renal stones ≥ 2 cm.

METHODS

This retrospective study was accomplished from January 2021 to February 2023. From 495 consecutives flexible ureteroscopies, 112 patients had renal stones ≥ 2 cm (60 patients with the use of UAS and 52 patients without). The stone-free status was verified after 8 weeks of operation.

RESULTS

The average diameter of the renal stones in non-UAS or UAS treated groups was 22.5 mm and 22.6, respectively. None of the groups differed significantly in terms of stone side, stone size, stone position, or Hounsfield unite but there was significant difference (p < 0.001) among two groups as regard pre-operative stenting (cases with UAS had 23.3% pre-operative stenting).

CONCLUSIONS

It is not always necessary to use UAS in conjunction with flexible ureteroscopy and laser lithotripsy to treat renal calculi bigger than or equal two cm. Without the assistance of UAS, the surgery may be carried out successfully and safely.

Improving Outcomes of Same-sitting Bilateral Flexible Ureteroscopy for Renal Stones in Real-world Practice-Lessons Learnt from Global Multicenter Experience of 1250 Patients

Background

Bilateral kidney stones are commonly treated in staged procedures.

Objective

To evaluate outcomes after same-sitting bilateral retrograde intrarenal surgery (SSB-RIRS) for renal stones.

Design setting and participants

Data from adults who underwent bilateral RIRS in 21 centers were retrospectively reviewed (from January 2015 to June 2022). The inclusion criteria were unilateral/bilateral symptomatic bilateral stone(s) of any size/location in both kidneys and bilateral stones on follow-up with symptom/stone progression. Stone-free rate (SFR) was defined as absence of any fragment >3 mm at 3 mo.

Outcome measurements and statistical analysis

Continuous variables are presented as medians and 25-75th percentiles. A multivariable logistic regression analysis was performed to evaluate independent predictors of sepsis and bilateral SFR.

Results and limitations

A total of 1250 patients were included. The median age was 48.0 (36-61) yr. Of the patients, 58.2% were prestented. The median stone diameter was 10 mm on both sides. Multiple stones were present in 45.3% and 47.9% of the left and right kidneys, respectively. Surgery was stopped in 6.8% of cases. The median surgical time was 75.0 (55-90) min. Complications were transient fever (10.7%), fever/infection needing prolonged stay (5.5%), sepsis (2%), and blood transfusion (1.3%). Bilateral and unilateral SFRs were 73.0% and 17.4%, respectively. Female (odds ratio [OR] 2.97, 95% confidence interval [CI] 1.18-7.49, p = 0.02), no antibiotic prophylaxis (OR 5.99, 95% CI 2.28-15.73, p < 0.001), kidney anomalies (OR 5.91, 95% CI 1.96-17.94, p < 0.001), surgical time ≥100 min (OR 2.86, 95% CI 1.12-7.31, p = 0.03) were factors associated with sepsis. Female (OR 1.88, 95% CI 1.35-2.62, p < 0.001), bilateral prestenting (OR 2.16, 95% CI 1.16-7.66, p = 0.04), and the use of high-power holmium:YAG laser (OR 1.63, 95% CI 1.14-2.34, p < 0.01) and thulium fiber laser (OR 2.50, 95% CI 1.32-4.74, p < 0.01) were predictors of bilateral SFR. Limitations were retrospective study and no cost analysis.

Conclusions

SSB-RIRS is an effective treatment with an acceptable complication rate in selected patients with kidney stones.

Patient summary

In this large multicenter study, we looked at outcomes after same-sitting bilateral retrograde intrarenal surgery (SSB-RIRS) for renal stones in a large cohort. We found that SSB-RIRS was associated with acceptable morbidity and good stone clearance after a single session.

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.

Effect of ureteric access sheath on outcomes of retrograde intrarenal surgery for renal stone disease: a randomized controlled trial

BACKGROUND

The need of ureteric access sheath (UAS) in retrograde intrarenal surgery (RIRS) has been controversial for gaining high success in terms of stone free rate (SFR), reducing operative times and complications. There has been lack of high level of evidence in the literature on this topic.

MATERIALS AND METHODS

This prospective randomized controlled trial (RCT) was conducted in the Department of Urology, PGIMER, Chandigarh from July 2019 to Dec 2021. The effect of UAS on the outcome of RIRS (SFR, operative time and complications) for renal stone disease was assessed. Ninety patients were randomized into two groups: 41 patients in Group 1 (RIRS with UAS) and 40 patients in Group 2(RIRS without UAS) were finally analyzed after exclusion. All the patients underwent preoperative double J stent placement at least 10 days prior to the definitive procedure. Operative time was recorded and postoperative pain was assessed by visual analogue scale(VAS) at 6 and 24 h postoperatively. Complications and emergency visits were recorded up to one month post procedure. SFR was assessed at 1 month using noncontrast CT KUB. Success was defined as absence of any residual fragment more than 3 mm in maximum diameter.

RESULTS

Demographic parameters (age, body mass index, and comorbidities) and preoperative parameters (stone burden, proportion of recurrent stone formers and proportion of patients with inferior calyceal stones) were comparable between the two groups. Operative times (45.49 vs 48.38 min; p - 0.484) and VAS scores at 6 and 24 h post-op (p - 0.577) were also comparable between Group 1 and Group 2. SFR was comparable in Group 1 and Group 2 (78.05% vs 80%, p - 0.829). Postoperative complications were higher in the UAS group, but not statistically significant (4.88% vs 0%; p - 0.157).

CONCLUSION

The use of UAS during RIRS is not associated with improved SFR. RIRS can be performed safely without the use of UAS and without increasing postoperative complications.

Effectiveness and Safety of Ureteroscopic Lithotripsy in Young, Old-Old, and Oldest Old Patients

Objectives: To investigate the efficacy and safety of ureteroscopic lithotripsy (URSL) in young, old-old, and oldest old patients. Materials and Methods: We enrolled 157 patients who underwent URSL. We divided the patients into young (<65 years), old-old (65-84 years), and oldest old (≥85 years) groups and compared the safety of surgery between young vs old-old and young vs oldest old, separately. Results: In the <65 group, 65 to 85 group, and ≥85 group, respectively, the mean stone diameters were 8.9 ± 4.9, 10.8 ± 7.7, and 11.4 ± 6.3 mm; mean operative time was 76.6 ± 33.1, 86.7 ± 44.7, and 84.0 ± 44.5 min; the stone-free rates were 95.9%, 94.4%, and 96.3%; and the complication rates were 8.2%, 9.8%, and 3.7%. Conclusions: In this study, we showed the feasibility and safety of URSL for elderly people. Although oldest old (≥85 years) people had multiple comorbidities with low performance status, URSL could be performed with acceptable complication rates. Clinical Trial Registration Number: 1809-1.

Superselective renal arterial embolization in treatment for severe renal hemorrhage after flexible ureterorenoscopy and laser lithotripsy (FURSL)

OBJECTIVE

Life-threatening renal hemorrhage after flexible ureterorenoscopy and laser lithotripsy (FURSL) is a rare complication. We aim to review our unit's experience with super-selective renal artery embolization as therapeutic options for such patients.

METHODS

From January 2015 to November 2021, total 1125 patients underwent the FURSL procedures in our unit. Patients with life-threatening renal hemorrhage were reviewed and the information of peri-operative, operative and post-operative were recorded.

RESULTS

Of the 1125 patients who underwent FURSL procedure, two patients with life-threatening renal hemorrhage were diagnosis; the age is 67 and 42 years old, respectively. Preoperative imaging examination showed that two patients had upper ureteral stone and renal stone ranging in size from 1.2 to 3.0 cm. Female patient placed the D-J stent for two weeks before FURSL. After the operation, both patients had the massive gross hematuria, significant drop of hemoglobin (Hgb), blood pressure lowering and needed to transfusion. CT scan showed that the male patient had an intrarenal hematoma. All these two were treated by super-selective renal artery embolization and had a successful outcome.

CONCLUSION

Life-threatening renal hemorrhage after FURSL is a rare and severe complication. Super-selective renal artery embolization is a safe and effective method for the treatment of patients with severe renal hemorrhage, preserving healthy renal parenchyma and renal function.

The clinical outcomes of flexible ureteroscopy and laser lithotripsy (FURSL) for treatment of the upper urinary tract calculi

PURPOSE

To evaluate efficacy and safety of flexible ureteroscopy and laser lithotripsy (FURSL) for treatment of the upper urinary tract calculi.

METHODS

We retrospectively analyzed 784 patients who underwent FURSL between January 2015 and October 2020 in our unit. All patients were preoperatively evaluated with urine analysis, serum biochemistry, urinary ultrasonography, non-contrast computed tomography and intravenous urography. The procedure was considered as successful in patients with complete stone disappearance or fragments < 4 mm on B ultrasound or computed tomography. The operative parameters, postoperative outcomes and complications were recorded and analyzed respectively.

RESULTS

The average operative time and postoperative hospital stay were 46.9±15.8 min and 1.2±1.1 days, respectively, among 784 patients. In addition, 746 patients were followed up and 38 patients were lost. In these patients, 700 (93.8%) cases met the stone removal criteria and 46 cases (6.2%) did not meet the stone removal criteria who need further treatment. The stone free rate (SFR) is 92.5%after 1-3 months and SFR of middle and upper calyceal calculi was higher than that of lower calyceal calculi significantly. The most common complications were fever (58/784, 7.4%), gross hematuria (540/784, 68.9%) and lpsilateral low back pain (47/784, 6.0%). The incidence rate of serious complication was 1.28%(10/784), including 5 cases of septic shock and 5 cases of subcapsular hematoma, which were cured after active treatment.

CONCLUSION

FURSL is a reliable treatment for small and medium calculi patients of upper urinary tract. The curative effect of stone removal is clear. The complications are few and the safety is high. However, there are certain limitations to the efficacy in treating larger stone and lower calyceal calculi.

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.

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.

[OUTCOMES OF CHRONIC UNILATERAL HEMATURIA TREATED USING DIGITAL FLEXIBLE URETEROSCOPE]

(Objectives) We examined the treatment outcomes in cases of chronic unilateral hematuria treated using flexible ureteroscope for observation and hemostasis. (Methods) The study included 14 patients (7 men and 7 women) with a median age of 56.5 years who underwent ureteroscopy using a digital flexible ureteroscope for chronic unilateral hematuria between March 2014 and August 2019. All the patients presented with macroscopic hematuria as a clinical symptom, but in one patient, the hematuria was accompanied by anemia and required a blood transfusion. In addition, bleeding occurred on the left side in 8 patients and on the right side in 3 patients; however, for the remaining 3 patients, the affected side could not be identified. Fourteen patients were examined on the basis of the ureteroscopic findings, number of bleeding sites, hemostatic intervention, treatment effect, and presence or absence of recurrences. (Results) The ureteroscopic findings showed a hemangioma in 7 patients and minute venous rupture in 3, but the remaining 4 patients showed no clear findings. The site of the findings was in the superior calyces in 8 cases, middle calyces in 4 cases, inferior calyces in 4 cases, and renal pelvic wall in 1 case. In addition, the findings were located at multiple sites in 6 cases, including all renal calyces in 2 cases. Ten patients with findings underwent hemostatic interventions (electrocoagulation and laser treatment). The median postoperative follow-up period was 32.4 months (range, 6.4-65.4 months). In all the cases, the hematuria disappeared after treatment. One of the 2 patients with findings in all renal calyces showed recurrence of macroscopic hematuria at 1 year and 6 months, which disappeared after conservative treatment. (Conclusions) In this study, observation using digital flexible ureteroscope was useful in the treatment of chronic unilateral hematuria, and the hemostatic interventions performed on the bleeding sites in the renal pelvis were effective.

Gap between UAS and ureteroscope predicts renal stone-free rate after flexible ureteroscopy with the fragmentation technique

PURPOSE

To assess the effect of our new classification on surgical outcomes after flexible ureteroscopy (fURS) for kidney stones.

METHODS

We retrospectively examined 128 patients after single renal fURS procedures performed using ureteral access sheaths (UASs) with the fragmentation technique. Based on the gap (calculated by subtracting the ureteroscope diameter from the UAS diameter), enrolled patients were divided into three groups: small (< 0.6 mm), medium (0.6 to < 1.2 mm), and large space groups (≥ 1.2 mm). Stone-free (SF) status was defined as either complete absence of stones (SF) or the presence of stones < 4 mm in diameter on non-contrast computed tomography (NCCT).

RESULTS

The SF rate was significantly lower in the small space group (50% in small, 97.9% in medium, 89.2% in large; p = 0.001). Perioperative complications over Clavien-Dindo Grade I were observed in 16.7%, 4.2%, and 8.1% of patients, respectively (p = 0.452). The ratio of stone volume and operative time (efficiency of stone removal) was significantly higher in the large space group compared to the small and medium space groups (0.009 ± 0.003 ml/min, 0.013 ± 0.005 ml/min, 0.027 ± 0.012 ml/min, respectively; p < 0.001).

CONCLUSION

Our findings that gaps > 0.6 mm (1.8 Fr), including the combination of a 9.5-Fr UAS and a small caliber ureteroscope, improve SF rates, and larger gaps facilitate stone removal efficiency providing the basis for future development of clinical protocols aimed at improving outcomes.

Outcomes with ureteral access sheath in retrograde intrarenal surgery: a retrospective comparative analysis

BACKGROUND

Retrograde intrarenal surgery is used for treatment of urinary system stones. The ureteral access sheath (UAS) is used to decrease intrapelvic pressure, help with access of multiple instruments, and facilitate drainage and removal of the fragmented stones.

OBJECTIVE

Assess the effect of the UAS on the outcomes of retrograde intrarenal surgery.

DESIGN

A retrospective patient data review.

SETTING

Training and research hospital in Turkey.

PATIENTS AND METHODS

We reviewed the data of patients who had undergone retrograde intrarenal surgery between 2012-2019. Patients who had kidney anomalies, were <18 years old, and who had ureteral and urethral strictures were excluded from the study. The demographic characteristics, stone type, complications, intraoperative and postoperative data of the patients were reviewed. A successful outcome was defined as being stone free or having clinically insignificant residual fragments (<3 mm). The use of the UAS was compared with other procedures in terms of efficiency and safety. Factors determining UAS usage were assessed by multivariate analysis.

MAIN OUTCOME MEASURES

Stone free rate and complication rate in patients who underwent retrograde intrarenal surgery.

SAMPLE SIZE

1808 patients met inclusion criteria.

RESULTS

The UAS was used in 1489 procedures, while other methods were used in 319 procedures. Operation time was 46.9 (17.3) minutes and 42.9 (19.0) minutes with other methods. Postoperative double J stent usage rates were 88.2% and 63% in the UAS and other methods, respectively. The rate of successful outcome was 88.2% and 81.2% in the UAS and other methods, respectively (P<.001). The rate of complications was similar in both groups (P=.543). In a multivariate analysis, UAS usage was directly proportional with stone size and inversely proportional with preoperative JJ stent usage CONCLUSION: The UAS can be effectively and successfully used in retrograde intrarenal surgery for treatment of urinary system stones. UAS usage should be considered for the patients who have large stones (2 cm) and do not have a preoperative double J stent.

LIMITATIONS

Retrospective design.

CONFLICT OF INTEREST

None.

Characterization of intracalyceal pressure during ureteroscopy

PURPOSE

To provide the first report of measuring intracalyceal pressures during ureteroscopy (URS).

METHODS

A prospective single-center clinical study using a cardiac pressure guidewire to measure intracalyceal pressure during flexible URS was performed. Eight patients (45 calyces) undergoing URS for nephrolithiasis were included. A Verrata^® pressure guide wire was passed through the working channel of a dual lumen flexible ureteroscope and into the calyces while irrigation was maintained at 150 mmHg. Pressure was measured in the renal pelvis, upper pole, interpolar, and lower pole calyces both with and without a ureteral access sheath (UAS). The pressure in each location with and without a UAS was compared. The correlation between calyceal pressure and infundibular dimensions (width, length) was determined.

RESULTS

Intracalyceal pressure was significantly lower in each region when a UAS was used. Compared to patients with a 12/14Fr UAS, those with a 14/16Fr UAS had significantly lower pressure in the interpolar (25.3 ± 13.1 vs. 44.0 ± 27.5 mmHg, p = 0.03) and lower pole (16.2 ± 3.5 vs. 49.2 ± 40.3 mmHg, p = 0.004) calyces. Interpolar calyceal pressure in the presence of a UAS was significantly higher than the renal pelvis pressure (RPP) (30.8 ± 19.6 vs. 17.9 ± 11.0 mmHg, p = 0.004).

CONCLUSIONS

During flexible URS, RPP strongly correlates with, but does not uniformly represent, the intracalyceal pressure. With a 14/16Fr UAS and an inflow pressure of 150 mmHg, RPP and intracalyceal pressure never exceed the threshold for renal backflow.

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.

Which is the best treatment of pediatric upper urinary tract stones among extracorporeal shockwave lithotripsy, percutaneous nephrolithotomy and retrograde intrarenal surgery: a systematic review

Background

Although the indications of minimally invasive treatments for pediatric urolithiasis are similar to those in adults, it is still crucial to make the right treatment decision due to the special considerations of children. This review aims to evaluate the efficacy and safety of extracorporeal shockwave lithotripsy (SWL), percutaneous nephrolithotomy (PCNL), and retrograde intrarenal surgery (RIRS) in the management of pediatric upper urinary tract stones.

Methods

EMBASE, PubMed, and the Cochrane Library were searched from their first available date to March 2018. The studies that meet the inclusive criteria were included. The efficacy and safety of the treatments were assessed by means of meta-analysis of the stone free rate (SFR), complication rate, effectiveness quotient (EQ) and secondary outcome indicators.

Results

A total of 13 comparative studies were identified for data analysis. PCNL presented a significantly higher SFR compared with SWL. Similarly, the single-session SFR of RIRS was significantly higher than SWL. However, no significant difference was found between RIRS and SWL in the overall SFR. There was no significant difference between PCNL and RIRS in the SFR. Furthermore, no significant differences in complication rates were found among the three therapies. Compared with the other two treatments, PCNL had a longer operative time, fluoroscopy time and hospital stay. SWL had a shorter hospital stay, higher retreatment rate and auxiliary rate in comparison with the other two treatments. The present data also showed that PCNL presented a higher EQ than the other two treatments, and RIRS had a lower efficiency than SWL and PCNL. In the subgroup analysis of pediatric patients with stone ≤20 mm, the comparative results were similar to those described above, except for the higher complication rate of PCNL than SWL.

Conclusions

Although SWL as an outpatient procedure provides shorter hospital stay and reduces operative time, it has a lower SFR and higher retreatment rate than the other two treatments. PCNL exhibits a higher SFR and EQ than SWL; nevertheless, it has a longer operative time and fluoroscopy time than the other two procedures. RIRS offers a similar SFR as PCNL but a lower efficiency than PCNL.

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.

Ureteral access sheaths: a comprehensive comparison of physical and mechanical properties

Introduction:

Ureteral access sheaths (UAS) facilitate flexible ureteroscopy in the treat- ment of urolithiasis. The physical properties of UAS vary by manufacturer and model. We compared three new UAS: Glideway (GW, Terumo, 11/13Fr, 12/14Fr), Pathway (PW, Terumo 12/14F) and Navigator HD (NHD, Boston Scientific, 11/13Fr, 12/14Fr) in the domains of safety characteristics, positioning characteristics, lubricity and radio- opacity.

Materials and Methods:

In vitro testing of the three UAS included safety testing-tip perforation force, sheath edge deformation and dilator extraction forces. Positioning characteristics tested included tip bending, stiffness (resistance to coaxial buckling forces), kinking (resistance to perpendicular forces), and insertion forces. Lubricity was assessed by measured frictional forces of the outer sheath. Finally, radio-opacity was tested utilizing fluoroscopic imaging of the three 12F sheaths and inner dilators.

Results:

The PW (0.245 lb) and GW (0.286 lb) required less force for tip perforation compared to the NHD (0.628 lb). The NHD sheath edge deformation was mild compared to more severe deformation for the PW and GW. The PW (1.008 lb) required greater force than the GW (0.136 lb) and NHD (0.043 lb) for inner dilator removal. The GW (3.69 lbs) and NHD (4.17 lb) had similar inner dilator tip stiffness when bent, while the PW had the weakest inner dilator tip, 1.91 lbs. The PW (0.271 lb) was most susceptible to buckling and kinking (1.626 lb). The most lubricious UAS was the NHD (0.055 lbs for 12F). The NHD (0.277 lbs) required the least insertional force through a biological model and possessed the greatest radio-opacity.

Conclusions:

Comparison of different commercially available UAS in various sizes reveals that there are mechanical differences in sheaths that may play a role clinically. The Terumo sheaths' (GW and PW) were outperformed by the Boston Scientific NHD in simulating safety, ease of use and radio-opacity.

Systematic review of ureteral access sheaths: facts and myths

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

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.

The surgical experience influences the safety of retrograde intrarenal surgery for kidney stones: a propensity score analysis

The aim of this study is to evaluate if surgical experience could influence the outcomes of retrograde intrarenal surgery (RIRS) in terms of stone clearance and complication rate. Patients from five institutions were included in this study. Patients were divided into two groups. Group 1: patients treated by three surgeons in the early phase of learning curve (surgical experience <100 procedures); Group 2: cases operated by two surgeons with great endourological experience (>400 procedures). Patients and stone characteristics, outcome and complications were analyzed. Multivariable regression model was used. Differences between groups were estimated using propensity scores to adjust for the bias inherent to the different characteristics. 381 RIRS were analyzed (Group 1: 150 RIRS; Group 2: 231 RIRS). Clinical data and stone parameters were comparable. The SFR was 70 % in Group 1 and 77.9 % in Group 2 (p = 0.082). Operative time was significantly shorter in the Group 2 (76.3 vs. 53.1 min, p = 0.001). The overall complication rate was significantly lower in Group 2 (20.7 vs. 8.7, p = 0.001). At unadjusted analysis, a non-significant difference was found between centers on SFR (OR 1.51 95 % CI 0.95-2.41). Conversely, a significant difference was found on overall complications (OR 0.36 95 %CI 0.20-0.67) with lower overall complication in Group 2. This study shows that surgeon experience influences the outcomes of RIRS mainly in terms of safety. Further studies will be needed to assess the exact number of procedures necessary to obtain a plateau in the rate of complications and success.

Benefits and risks of ureteral access sheaths for retrograde renal access

PURPOSE OF REVIEW

Ureteral access sheath (UAS) became increasingly popular worldwide. However, the safety of its routine use remains controversial. The aim of the current revision is to provide a systematic review on the benefits and disadvantages of the UAS.

RECENT FINDINGS

A systematic review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria. Two reviewers independently searched the literature, finally identifying 20 articles valuable for this review. The use of UAS demonstrated several advantages to facilitate retrograde intrarenal access, lower intrarenal pressure, protect the ureter, protect the scope, and expedite stone extraction. Despite this, there is also some evidence that UAS use may be associated with acute ureteral injury and long-term complications, apparently related to maneuvers for UAS insertion and mucosal or deeper layers of injury and ischemia. Furthermore, there are still pending questions on the possible increase in stone-free rates, and decrease in operative time and costs.

SUMMARY

Although the use of UAS is associated with some risk and limiting factors, it appears from this systematic review that its use is common and safe for the retrograde intrarenal access. Therefore, UAS is highly recommended for the treatment of upper tract disease by means of retrograde intrarenal surgery.

Use of ureteral access sheaths in ureteroscopy

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

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

INTRODUCTION

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Incidence and Predictors for Ipsilateral Hydronephrosis Following Ureteroscopic Lithotripsy

OBJECTIVE

To review our experience in using ureteroscopy (URS) with lithotripsy for renal or ureteral calculi to determine the incidence and predictors of postprocedural ipsilateral hydronephrosis.

PATIENTS AND METHODS

Records of 324 URS cases for renal or ureteral calculi with imaging performed 4-12 weeks postprocedure were reviewed. Ipsilateral hydronephrosis was determined by computed tomography scan or renal ultrasound. Univariate and multivariate analyses determined the factors associated with hydronephrosis.

RESULTS

176 men and 148 women with a median age of 50 years were included. Median stone size was 6 mm and operative duration was 60 minutes; 30% of patients had multiple calculi; and 35% had undergone a prior ipsilateral URS. Overall, 49 of 324 patients (15%) had evidence of hydronephrosis, with 65% of these patients having symptoms and 40% requiring ancillary procedures. On multivariate analysis, increasing stone diameter (odds ratio [OR] 8.9, 95% confidence interval [CI] 1.9-23.8, P = .03), prior ipsilateral URS (OR 7.7, 95% CI 1.8-28.2, P = .006), longer operative duration (OR 6.5, 95% CI 1.8-16.3, P = .02), and renal colic symptoms (OR 48.3, 95% CI 14.7-71.4, P <.001) independently predicted hydronephrosis. Conversely, other factors including stone impaction at procedure, ureteral dilation, use of an access sheath, intraoperative perforation, or use of a stent did not associate with ipsilateral hydronephrosis.

CONCLUSION

In this contemporary cohort study, 15% of patients undergoing URS had evidence of ipsilateral hydronephrosis. Larger stone size, longer OR duration, prior ipsilateral URS, and recurrent colic were associated with an increased likelihood for this observation. Patients and stone cases with such characteristics likely warrant imaging modalities beyond plain radiography.

Ureteroscopy for treatment of upper urinary tract stones in children: technical considerations

The incidence of pediatric urolithiasis is increasing. While many smaller stones may pass spontaneously, surgical therapy is sometimes warranted. Surgical options include shock wave lithotripsy, ureteroscopy, percutaneous nephrolithotomy, and open surgery. Ureteroscopy represents a minimally invasive approach, and it is increasingly being used to treat pediatric upper tract calculi. Ureteroscopy is performed under anesthesia and fluoroscopic guidance, with basket extraction or lithotripsy of the calculi. Technical considerations include active or passive ureteral dilatation, the use of ureteral access sheaths for larger stone burdens, and post-operative stent placement. The current pediatric literature suggests high success rates (equal to or surpassing shock wave lithotripsy) and low complication rates. However, concerns remain regarding feasibility in patients with variant anatomies and risk due to intra-operative radiation exposure.

Efficacy and safety of Ho:YAG laser lithotripsy for ureteroscopic removal of proximal and distal ureteral calculi

Background

Laser lithotripsy is an established endourological modality. Ho:YAG laser have broadened the indications for ureteroscopic stone managements to include larger stone sizes throughout the whole upper urinary tract. Aim of current work is to assess efficacy and safety of Ho:YAG laser lithotripsy during retrograde ureteroscopic management of ureteral calculi in different locations.

Methods

88 patients were treated with ureteroscopic Ho:YAG laser lithotripsy in our institute. Study endpoint was the number of treatments until the patient was stone-free. Patients were classified according to the location of their stones as Group I (distal ureteric stones, 51 patients) and group II (proximal ureteral stones, 37). Group I patients have larger stones as Group II (10.70 mm vs. 8.24 mm, respectively, P = 0.020).

Results

Overall stone free rate for both groups was 95.8%. The mean number of procedures for proximal calculi was 1.1 ± 0.1 (1–3) and for distal calculi was 1.0 ± 0.0. The initial treatment was more successful in patients with distal ureteral calculi (100% vs. 82.40%, respectively, P = 0.008). No significant difference in the stone free rate was noticed after the second laser procedure for stones smaller versus larger than 10 mm (100% versus 94.1%, P = 0.13). Overall complication rate was 7.9% (Clavien II und IIIb). Overall and grade-adjusted complication rates were not dependant on the stone location. No laser induced complications were noticed.

Conclusions

The use of the Ho:YAG laser appears to be an adequate tool to disintegrate ureteral calculi independent of primary location. Combination of the semirigid and flexible ureteroscopes as well as the appropriate endourologic tools could likely improve the stone clearance rates for proximal calculi regardless of stone-size.

Differences in ureteroscopic stone treatment and outcomes for distal, mid-, proximal, or multiple ureteral locations: the Clinical Research Office of the Endourological Society ureteroscopy global study

BACKGROUND

Ureteroscopy has traditionally been the preferred approach for treatment of distal and midureteral stones, with shock wave lithotripsy used for proximal ureteral stones.

OBJECTIVE

To describe the differences in the treatment and outcomes of ureteroscopic stones in different locations.

DESIGN, SETTING, AND PARTICIPANTS

Prospective data were collected by the Clinical Research Office of the Endourological Society on consecutive patients treated with ureteroscopy at centres around the world over a 1-yr period.

INTERVENTION

Ureteroscopy was performed according to study protocol and local clinical practice guidelines.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Stone location, treatment details, postoperative outcomes, and complications were recorded. Pearson's chi-square analysis and analysis of variance were used to compare outcomes among the different stone locations.

RESULTS AND LIMITATIONS

Between January 2010 and October 2012, 9681 patients received ureteroscopy treatment for stones located in the proximal ureter (n=2656), midureter (n=1980), distal ureter (n=4479), or multiple locations (n=440); location in 126 patients was not specified. Semirigid ureteroscopy was predominantly used for all stone locations. Laser and pneumatic lithotripsy were used in the majority of cases. Stone-free rates were 94.2% for distal ureter locations, 89.4% for midureter locations, 84.5% for proximal ureter locations, and 76.6% for multiple locations. For the proximal ureter, failure and retreatment rates were significantly higher for semirigid ureteroscopy than for flexible ureteroscopy. A low incidence of intraoperative complications was reported (3.8-7.7%). Postoperative complications occurred in 2.5-4.6% of patients and varied according to location, with the highest incidence reported for multiple stone locations. Limitations include short-term follow-up and a nonuniform treatment approach.

CONCLUSIONS

Ureteroscopy for ureteral stones resulted in good stone-free rates with low morbidity.

PATIENT SUMMARY

This study shows that patients who have ureteral stones can be treated successfully with ureteroscopy with a low rate of complications for the patient.

Which ureteral access sheath is compatible with your flexible ureteroscope?

PURPOSE

Our aim is to evaluate different ureteral access sheaths (UASs), which are available in the international market and their compatibility with different available flexible ureteroscopes (F-URSs) to help the urologist choose the proper ureteral access sheath for his or her endoscope before commencing the procedure.

MATERIALS AND METHODS

A total of 21 UASs and 12 F-URSs were evaluated. Measurements were obtained in French (F) units considering different characteristics for each UAS and each F-URS. Insertion test without friction between F-URS and UAS was considered as a successful test and was referred as (YES).

RESULTS

All UASs and F-URSs were successfully submitted to the insertion test. All F-URSs that were inserted into UASs without friction had an internal diameter of at least 12F. Different lengths of UAS did not influence the test outcome.

CONCLUSION

This study was able to establish a correlation table between different UASs and different flexible ureteroscopes. As of now, the 12/14F UAS is considered the universal UAS that accepts all F-URSs that are available in the endourology field. Nevertheless, we are expecting a significant change with the new standard size 10/12F UAS as well as huge advances in minimizing the size of different endoscopes.

Flexible ureteroscopy with a ureteral access sheath: when to stent?

OBJECTIVE

To compare intra- and postoperative data of patients who underwent ureterorenoscopy (URS) with an access sheath, with and without postoperative stenting.

METHODS

We retrospectively identified patients who underwent flexible URS with a ureteral access sheath between January 2102 and January 2013. Two surgeons performed all cases; one who routinely stents after flexible ureteroscopy and a second who selectively stents. Fifty-one patients who were stented and 51 patients not stented after URS were enrolled in this study. Patients were matched by operative time as a surrogate measure of complexity of the procedure. Intra- and postoperative data were compared. We also analyzed if preoperative stenting or sheath diameter had any effect on postoperative pain score for each group.

RESULTS

Patients in the stented group were older (P <.001), had larger ureteral access sheaths (P <.001), and greater stone burden (P <.001). Despite this, the stented group had lower pain scores (4.5 ± 3.2 vs 8.9 ± 3.2; P = .025) and were less likely to seek medical assistance for pain than the unstented patients (26.3% vs 3.9%; P = .007). Patients who were prestented before ureteroscopy had lower pain scores than those who were not prestented in the group that did not receive a postoperative stent (4.2 ± 3.4 vs 6.6 ± 2.8; P = .047).

CONCLUSION

Postoperative stenting after flexible URS with a ureteral access sheath seems to decrease postoperative pain. Patients might be selected for no ureteral stent if they were prestented before the procedure, and the URS was uneventful.

The use of a ureteral access sheath does not improve stone-free rate after ureteroscopy for upper urinary tract stones

PURPOSE

To evaluate the impact of a ureteral access sheath (UAS) on stone-free (SF) rate after flexible ureteroscopy for upper urinary tract stones.

MATERIALS AND METHODS

We retrospectively reviewed 280 patients who underwent flexible ureteroscopy (URS) for upper urinary tract stone between 2009 and 2012. Patients were divided into two groups based on whether a UAS was used (n = 157) or not (n = 123). SF rate was evaluated at one and three months after surgery by abdominal imaging. Quantitative and qualitative variables were compared with Student's t test and χ2 test, respectively. A logistic regression model was used to determine the predictive factors of SF status.

RESULTS

Stone size was similar in both groups (15.1 vs. 13.7 mm, p = 0.21). SF rates at one and 3 months were comparable in UAS and non-UAS groups (76 vs. 78% and 86 vs. 87%, p = 0.88 and 0.89, respectively). Complication rates were similar in both groups (12.7 vs. 12.1%, p = 0.78). In multivariable analysis, stone size was the only predictive factor of SF rate (p = 0.016).

CONCLUSION

The routine use of a UAS did not improve SF rate in patients undergoing flexible URS for upper urinary tract calculi.

Ureteroscopy with and without safety guide wire: should the safety wire still be mandatory?

BACKGROUND AND PURPOSE

Although the evidence is sparse, most urologists advise the insertion of a safety guide wire (SGW) alongside the ureteroscope whenever performing ureteroscopy (URS). The aim of the study was to compare the results of ureteroscopic treatment for ureteral stones at the Oslo University Hospital (OUH), where the SGW is routinely used, with the results at the Haukeland University Hospital (HUH), where the SGW is routinely omitted. The primary goal was to evaluate the success rates of passing the ureteroscope through the orifice, the ability to access the ureteral stone, and the ability to place a ureteral stent when needed after the endoscopy. The secondary goals were to compare the perioperative complication rates and stone-free rates at the two hospitals.

MATERIALS AND METHODS

A retrospective review of 500 URS for ureteral calculi at each of the two hospitals, during 2004-2010, was performed. Relevant data were extracted from the medical records. The exact chi-squared, Mann-Whitney U, and independent-samples t-tests were used comparing the results at the two hospitals.

RESULTS

An SGW was used in 480 (96.2%) of the URS procedures at OUH and in 7 (1.4%) at HUH. No significant differences were found between the two hospitals in the success rates of passing the ureteroscope through the orifice, in the ability to access the ureteral calculus, or in the ability to place a ureteral stent when needed after the endoscopy. There were no significant differences in the number of intraoperative complications, but postendoscopic ureteral stenosis occurred more often at OUH (3.4%) than at HUH (1.2%), p=0.039. The overall stone-free rate was higher at HUH (85.9%) compared to OUH (77.1%), p=0.001.

CONCLUSION

No superior results were found at the hospital with the routine use of an SGW. It may be questioned if the SGW still should be considered mandatory.

Residual fragments following ureteroscopic lithotripsy: incidence and predictors on postoperative computerized tomography

PURPOSE

Residual fragments following ureteroscopy for calculi may contribute to stone growth, symptoms or additional interventions. We reviewed our experience with ureteroscopy for calculus disease to define the incidence and establish factors predictive of residual fragments.

MATERIALS AND METHODS

Records associated with 667 consecutive ureteroscopic lithotripsy procedures for upper urinary calculi were reviewed. In 265 procedures (40%) computerized tomography was done between 30 and 90 days postoperatively. They comprised the study group. Residual fragments were defined as any residual ipsilateral stone greater than 2 mm.

RESULTS

Included in the study were 121 men and 127 women with a mean age of 47 years. Mean target stone diameter was 7.6 mm. The stone location was the kidney in 30% of cases, ureter in 50%, and kidney and ureter in 20%. Residual fragments were detected on computerized tomography after 101 of 265 procedures (38%). Pretreatment stone size was associated with residual fragments at a rate of 24%, 40% and 58% for stones 5 or less, 6 to 10 and greater than 10 mm, respectively (p <0.001). Additionally, stone location in the kidney (p <0.001) or the kidney and ureter (p = 0.044), multiple calculi (p = 0.003), longer operative time (p = 0.008) and exclusive use of flexible ureteroscopy (p = 0.029) were associated with residual fragments. In a multivariate model only pretreatment stone diameter greater than 5 mm was independently associated with residual fragments after ureteroscopy (diameter 6 to 10 and greater than 10 mm OR 2.03, p = 0.03 and OR 3.74, p = 0.003, respectively).

CONCLUSIONS

Of patients who underwent ureteroscopic lithotripsy for calculi 38% had residual fragments by computerized tomography criteria, including more than 50% with stones 1 cm or greater. Such data may guide expectations regarding the success of ureteroscopy in attaining stone-free status.

The new digital flexible ureteroscopes: 'size does matter'--increased ureteric access sheath use!

OBJECTIVES

To evaluate whether the use of sheaths to access the ureter has increased after the introduction of new digital ureterorenoscopes in patients undergoing flexible ureteroscopy.

METHODS

140 patients with kidney stones were randomised to be scoped with either an old-generation fibre-optic flexible ureteroscope (DUR-8, Elite, ACMI; distal tip diameter = 6.75 Fr) or a new-generation digital LCD flexible ureteroscope (Invisio D-URD flexible ureteroscope; distal tip diameter = 8.7 Fr). We recorded the necessity to use a sheath to access the ureter, sheath-related and postoperative complications, and whether or not a JJ stent was left behind.

RESULTS

157 (80 fibre-optic and 77 digital) ureterorenoscopies were performed. Ureteral access sheaths were used significantly more frequently with digital scopes (p = 0.00174). Two patients in the digital scope group had a small distal ureteric perforation from the introducer sheath compared with none in the fibre-optic scope group.

CONCLUSIONS

A statistically significant increase in sheath use was observed in the new-generation digital flexible ureteroscopy group. Despite the improvement in image quality, better durability and improved stone clearance, there are some potential drawbacks of these scopes. The increased distal tip diameter can result in increased use of ureteric access sheaths and this may increase morbidity and expense.

Is stenting required before retrograde intrarenal surgery with access sheath

Background:

Flexible ureterorenoscopies continue to assume an increasing role in the armamentarium of the endourologist. In many centers around the world, prior stenting is carried out before retrograde intrarenal surgery (RIRS) to passively dilate the ureter, which facilitates passage of a flexible ureteroscope with or without an access sheath. In our series, the first stage of passive dilatation with prior stenting was totally avoided without compromising the success of the procedure.

Materials and Methods:

From January 2004 to December 2007, 54 patients with 55 renal units underwent RIRS. The patients were between 28 and 65 years old. All patients had renal stones ranging in size from 8 mm to 22 mm. The mean serum creatinine level was 1.1 mg%. The lower ureter was dilated under ‘C - arm’ fluoroscopy guidance up to 14 FR. An access sheath of 10/12 Fr was passed over the working guide wire. RIRS (7.5/9.3 Fr) was introduced into the access sheath. The stones were fragmented using a holmium laser. The mean operating time was 85 mins (45-130 mins).

Results:

In 52 out of 55 renal units (94.5%), a flexible ureteroscope could be passed successfully into the kidney through an access sheath. In 3 of the cases (5.4%), the lower ureter could not be dilated. In these patients, the procedure was staged after passing a 6/26 JJ stent. An X-ray KUB was done at the 3-month follow-up visit. A total of 50 renal units (94.3%) were stone free at the 3-month follow-up visit.

Conclusion:

In a majority of the cases, RIRS could be accomplished successfully during the first sitting. Single stage RIRS did not alter the subsequent stone clearance or increase the incidence of morbidity or complications.