Comparison of Different Ureteroscope Sizes in Treating Ureteral Calculi in Adult Patients

Efficacy and Safety of Semirigid Ureteroscopy Combined with Holmium:yttrium-aluminum-garnet Laser Lithotripsy for the Treatment of Proximal Ureteral Calculi: A Single-arm Meta-analysis

Background and objective

Ureteral stones are currently treated with holmium:yttrium-aluminum-garnet (Ho:YAG) laser lithotripsy using rigid and flexible ureteroscopes. This study aims to evaluate the efficacy and safety of semirigid ureteroscopy combined with Ho:YAG laser lithotripsy for treating proximal ureteral stones in real-world studies.

Methods

The PubMed, Embase, and Web of Science databases were searched systematically to retrieve all relevant studies up to April 2024. A meta-analysis of the retrieved studies was performed using Stata 14.0 software and expressed as rate, mean difference, and 95% confidence interval (CI). The main outcomes of this meta-analysis were stone-free rate (SFR) and perioperative outcomes including operation time, hospital stay, postoperative ureteral stent placement, auxiliary procedures, and intra- or postoperative complications.

Key findings and limitations

A total of 24 studies were included in this study, including 2058 patients with proximal ureteral stones. According to the results of the combined analysis, the SFR of semirigid ureteroscopy combined with Ho:YAG laser lithotripsy for the treatment of proximal ureteral stones was 78% (95% CI [75%, 82%]), operation time was 51.03 min (95% CI [43.5, 58.56]), hospital stay was 1.62 d (95% CI [1.54, 1.70]), auxiliary procedure rate was 20% (95% CI [15%, 25%]), and postoperative complication rate was 16% (95% CI [12%, 22%]).

Conclusions and clinical implications

The results of this study show that semirigid ureteroscopic Ho:YAG laser lithotripsy is a commonly used treatment for proximal ureteral calculi, but its efficacy and safety need to be improved further, and its efficacy is not related to the diameter of the endoscope.

Patient summary

This study showed that Ho:YAG laser lithotripsy with semirigid ureteroscopes is commonly used for treating ureteral stones. However, its efficacy and safety need to be improved further, and future research should focus on these.

Ureteral stricture rate after endoscopic treatments for urolithiasis and related risk factors: systematic review and meta-analysis

PURPOSE

We aimed to accurately determine ureteral stricture (US) rates following urolithiasis treatments and their related risk factors.

METHODS

We conducted a systematic review and meta-analysis following the PRISMA guidelines using databases from inception to November 2023. Studies were deemed eligible for analysis if they included ≥ 18 years old patients with urinary lithiasis (Patients) who were subjected to endoscopic treatment (Intervention) with ureteroscopy (URS), percutaneous nephrolithotomy (PCNL), or shock wave lithotripsy (SWL) (Comparator) to assess the incidence of US (Outcome) in prospective and retrospective studies (Study design).

RESULTS

A total of 43 studies were included. The pooled US rate was 1.3% post-SWL and 2.1% post-PCNL. The pooled rate of US post-URS was 1.9% but raised to 2.7% considering the last five years' studies and 4.9% if the stone was impacted. Moreover, the pooled US rate differed if follow-ups were under or over six months. Patients with proximal ureteral stone, preoperative hydronephrosis, intraoperative ureteral perforation, and impacted stones showed higher US risk post-endoscopic intervention with odds ratio of 1.6 (P = 0.05), 2.6 (P = 0.009), 7.1 (P < 0.001), and 7.47 (P = 0.003), respectively.

CONCLUSIONS

The overall US rate ranges from 0.3 to 4.9%, with an increasing trend in the last few years. It is influenced by type of treatment, stone location and impaction, preoperative hydronephrosis and intraoperative perforation. Future standardized reporting and prospective and more extended follow-up studies might contribute to a better understanding of US risks related to calculi treatment.

Evaluation of ultrathin semirigid ureteroscopy in terms of efficiency and cost compared to flexible ureteroscopy in treating proximal ureteric stones: a prospective randomized multicenter study

PURPOSE

To investigate the outcome and cost-effectiveness of ultrathin 6-7.5-Fr semirigid ureteroscopy in treating proximal ureteric stones compared to flexible ureteroscopy.

METHODS

Two hundred and twenty patients with a solitary proximal ureteric stone were eligible for ureteroscopy (stone size = 1-2 cm). Patients were randomly subdivided into two groups: Group I included 105 patients who underwent ultrathin semirigid ureteroscopy and group II included 115 patients who underwent flexible ureteroscopy. Both groups were compared regarding successful stone access, operation time, reoperation rates, the financial cost to stone-free, complications, and stone clearance at 4 and 8 weeks.

RESULTS

Groups I and II had no significant differences regarding patient demographics, stone criteria, and hospitalization time. In contrast, the mean operative time was significantly longer in group II (p < 0.001). The overall scope-to-stone access rate was 89.5%. It was 87.6% compared to 91.3% (p = 0.32), while the stone-free rate was 81.9% versus 87.8% (p = 0.22) for groups I and II, respectively. Intraoperative and postoperative complications were statistically insignificant between the study groups. The cost/person in Egyptian pounds was 8619 ± 350 in group I, compared to 17,620 ± 280 in group II (p < 0.001); similarly, the cost to attain the stone-free rate was 8950 ± 720 in group I compared to 17,950 ± 500 in group II.

CONCLUSION

Ultrathin semirigid ureteroscopy is safe, durable, and considered a cost-effective method for treating upper ureteric calculi compared to the flexible ureteroscopy and could be considered a first treatment option in developing countries.

Device Failure and Adverse Events Related to Single-use and Reusable Flexible Ureteroscopes: Findings and New Insights From an 11-Year Analysis of the Manufacturer and User Facility Device Experience Database

OBJECTIVE

To catalog and characterize device failures and adverse events related to flexible ureteroscopes from a national database.

METHODS

Search of the Manufacturer User and Facility Device Experience database was performed for all recorded events related to flexible ureteroscopes between 2012 and 2022. The following information was collected: Problem and cause, timing, complications and injury, prolonged anesthesia, and early termination of procedure. Event severity was graded using a validated tool.

RESULTS

A total of 206 events were identified (reusable/single use ratio, 2.5:1). There were 20 different problem categories reported, which included image loss (26.7%), difficulty removing scope (13.6%), scope damage from basket (4.4%), detachment of scope tip (5.8%) and contamination (4.9%). Faulty device was the predominant cause for an event related to single-use scopes (86.4%); this was seldom the case for reusable (2%). Patient injury occurred in 21.8%, but these were all in reusable scopes. No deaths were reported, but major complications included complete avulsion of the ureter (3.4%) and fully entrapped scope necessitating open surgery (2.9%). While the safety profile for single-use scopes was superior, they were significantly more likely to result in early termination (71.1% vs 37.3%, P < .001). This was related to 76.3% of the single-use scopes experiencing sudden image loss.

CONCLUSION

Flexible ureteroscopes are fragile, and a multitude of problems can occur. Many of these can be avoided through correct surgeon technique and robust maintenance services.

Randomized comparison of 4.5/6 Fr versus 6/7.5 Fr ureteroscopes for laser lithotripsy of lower/middle ureteral calculi: towards optimization of efficacy and safety of semirigid ureteroscopy

BACKGROUND AND PURPOSE

To compare 4.5/6 Fr versus 6/7.5 Fr semirigid ureteroscopes in terms of safety and efficacy in adult non-obese patients with middle or lower ureteric stones.

MATERIALS AND METHODS

A total of 198 patients with middle/lower ureteric stone and a BMI ≤ 30 kg/m² were recruited. Patients were randomized according to the size of ureteroscope into two groups: group 1 where a 4.5/6 Fr semi-rigid ureteroscope was used, and group 2 where a 6/7.5 Fr semi-rigid ureteroscope was used. Patient's demographic, stone characteristics, intraoperative and postoperative outcomes including stone-free rate (SFR) and complications were compared.

RESULTS

Preoperative characteristics in terms of age, sex, BMI, and stone location, side, size, and HU were comparable between both groups (p values > 0.05). The overall SFR was significantly higher in group 1 (0.004). Balloon dilatation was not required in all patients of group-1 compared with 33% of group-2 (p = 0.0001). The JJ stent was required in 10% of group-1 compared with 30% of group-2 (p = 0.0004). Failure to reach the stone due to tight ureter occurred in 8% of group 2 (p = 0.003), respectively. Traxer's grade 1 ureteral injury occurred in 2% of group-1 versus 14% of group-2 (p = 0.001). Consequently, hematuria was significantly lower in group-1 (1% vs. 8%; p = 0.01), respectively. The hospital stay < 9 h was significantly higher in group 1 (p = 0.0001).

CONCLUSIONS

The 4.5/6 Fr semi-rigid Ureteroscope was associated with significantly higher SFR and shorter hospital stay, with lower ureteral injury, fewer double-J stenting, and without the need for intraoperative balloon dilatation for the ureter.

The Innovative Use of Ureter Catheter in the Surgery of Obstructive Uropathy

Purpose

Relieving obstruction and protecting renal function are the main therapeutic purposes of obstructive uropathy which often involve surgical treatment, and the ureter catheter is one of the surgical instruments commonly used in surgery. We aimed to explore the innovative use of a ureter catheter in the surgery of obstructive uropathy.

Methods

We used a ureteral catheter to innovate the surgical procedure of the most common causes of obstructive uropathy: ureteral calculi and stricture, establishing an internal circulation system (ICS), proposing a three-step dilatation method, and reviewing their effects on patients. Furthermore, we introduced a simple real-time intrapelvic pressure measurement device to monitor intrarenal pressure during operation.

Results

Postoperative laboratory examination showed that blood CRP, leukocyte neutrophil level, changes in the hemoglobin, urine occult blood, and positive rate of urine culture in the ICS group are significantly lower than those in the control group, corresponding to a lower incidence of bleeding and infection-related complications clinically. A three-month follow-up revealed 1/3 rate of ureteral stricture in the ICS group comparing to the control. We applied the three-step dilatation in patients with severe stenosis in which the balloon could not pass; the overall effective rate was 90.9%. The pressure of the renal pelvis was displayed on the monitor in real time. The surgeon could estimate the degree of filling of the renal pelvis and adjust the intake volume through the data.

Conclusion

The innovative application of ureteral catheters in the operation of obstructive uropathy can realize the real-time monitor of intraoperative renal pelvis pressure, reduce the incidence of lithotripsy postoperative complications, and expand the indications of balloon dilatation in ureteral stricture, which has certain clinical significance.

Is the 4.5-F ureteroscope (Ultra-Thin) an alternative in the management of ureteric and renal pelvic stones?

Objectives

To compare the 7.5–9.5F ureteroscope (URS) with the 4.5–6.5F URS (Ultra-Thin) in terms of success and complication rates in adult patients with ureteric and renal pelvic stones.

Patients and methods

In all, 41 patients treated with 7.5–9.5F semi-rigid URS (Group 1) and 33 patients treated with the Ultra-Thin (Group 2) were prospectively included in the study. All patients underwent holmium laser ureteroscopic lithotripsy. In each group, when the selected ureteroscopic intervention failed to reach or disintegrate the stone, the URS was replaced with the other one. Outcome criteria were: success and complication rates, stone size and stone surface area, operative time, laser time, usage of guidewire, and postoperative JJ-catheter placement.

Results

The ureteroscopic lithotripsy in 36 of 41 (87.8%) and 24 of 33 (72.7%) patients was completed without a need to replace the URS with the other one in groups 1 and 2, respectively (P = 0.67). After replacement of the 7.5–9.5F URS with the Ultra-Thin for patients who failed in Group 1, the overall stone-free rate (SFR) improved to 97.5% (P = 0.014). In Group 2, after replacement of the Ultra-Thin with the 7.5–9.5F URS for the failed patients, the overall SFR improved to 96.9% (P = 0.02). There was no significant difference between the groups for complications. Postoperative JJ stenting was significantly less in Group 2 (21.2%) in comparison to Group 1 (46.3%) (P = 0.02).

Conclusions

The Ultra-Thin has a similar success rate as the 7.5–9.5F URS in the treatment of ureteric stones and is a feasible option in patients in whom a conventional URS cannot be advanced through any segment of the ureter.

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.

Experience of retaining encrusted ureteral stents: URL by 4.5/6.5F ureteroscope can reduce the possibility of PCNL

The purpose of the study was to present our experience of retaining encrusted ureteral stents (EUS) and discuss the effectiveness of 4.5/6.5F ureteroscope (URS) in the procedure. The data of patients with EUS in our center from January 2012 to December 2016 were retrospectively analyzed. The inclusion criterion was ureteral stents that required intervention above the ureteral orifice to retain and was proved to be encrusted. Impacted stents would be removed by ureteroscope lithotripsy (URL) via 8/9.8F or 4.5/6.5F URS. Percutaneous nephrolithotomy (PCNL) then be the further step if URL failed. 46 cases of EUS were treated in 36 patients from January 2012 to December 2016 in our institution. All subjects consisted of 18 males and 18 females; the average age was 49.81 ± 16.40 years (range 5-86). The mean time from stent insertion to encrustation was 9.28 ± 17.15 months (range 1-120). URL was performed in 44 cases (95.7%), including 19 cases (41.3%) by 8/9.8F URS and 25 cases (54.4%) by 4.5/6.5F URS due to the conventional URS's failure to get into ureteral orifice or further part of ureter. Two patients (4.3%) underwent PCNL due to the inseparable circle developed by the intra-renal segment of encrusted stents. None of the patients underwent extracorporeal shock wave lithotripsy (ESWL) and open surgery. All stents were eventually removed without blood transfusion or ureteral injury, except three cases with post-operative fever. All procedures were performed under one-session anesthesia. URL by 4.5/6.5F ureteroscope might increase the success rate of retaining encrusted ureteral stents remarkably, and then reduce the possibility of PCNL effectively.

Assessment of the Effectiveness, Safety, and Reproducibility of Micro-Ureteroscopy in the Treatment of Distal Ureteral Stones in Women: A Multicenter Prospective Study

PURPOSE

The aim of this study is to assess the effectiveness, safety, and reproducibility of the micro-ureteroscopy (m-URS) in the treatment of distal ureteral stones in women.

MATERIALS AND METHODS

A multicenter, prospective observational study was designed and conducted between March and December 2015. We included women having at least one stone in the distal ureter and being a candidate for surgical treatment using the 4.85F sheath of MicroPerc^®. Patients with clinical criteria and/or laboratory analysis indicating sepsis or coagulation alteration were excluded.

RESULTS

Thirty-nine women were operated in eight hospitals. The profile of the patients was fairly homogeneous among hospitals. Only differences were found in age, preoperative stent, and the result of the previous urine culture. Immediate stone-free status was achieved in 88.2% and 100% 7 days after the procedure. 97.4% of patients did not present any complication in the postoperative period, with only one case with complication Clavien II. Postureteroscopic Lesion Scale (PULS) in 76.9% of patients did not show any injury, 20.5% had lesions grade 1, and grade 2 lesions 2.6%. As for the reproducibility of m-URS between hospitals, statistical analysis of the results showed differences between all the centers participating in the study.

CONCLUSIONS

m-URS is an effective, safe, and reproducible technique that minimizes surgical aggression to the ureteral anatomy. Satisfactory and comparable results to "conventional" ureteroscopy were obtained in the treatment of distal ureteral stones in women, although clinical trials are needed. The reduction of the ureteral damage may reduce secondary procedures and increase the cost-effectiveness of the procedure.

The effect of ureteroscope size in the treatment of ureteral stone: 15-year experience of an endoscopist

OBJECTIVE

We aimed to investigate the ureter stone treatment results performed by using different- caliber semirigid ureteroscopes (URS).

MATERIAL AND METHODS

Adult patients who were treated for ureteral stones by a single endoscopist between January 2000 and March 2015 were analyzed. The patients were divided into 3 groups in accordance with the caliber of the ureteroscope used: 10/10.5 F Storz (Karl Storz, Tuttlingen, Germany) (January 2002-January 2005) URS was used in group 1, 8.9/9.8 F Storz (February 2005-December 2011) URS was used in group 2, and 6/7.5 FWolf (Richard Wolf, Knittlingen, Germany) (January 2012-March 2015) URS was used in group 3. Patients' age and gender, size and site of stones, stone-free rates (SFR), intra- and perioperative complication rates, and durations of surgery were compared among the groups. Intraoperative complications were classified according to modified Satava, and perioperative complications were classified according to modified Clavien classification systems.

RESULTS

A total of 2461 patients treated for ureteral stones were analyzed. There were 583 patients in group 1 (10/10.5 F Storz), 1302 patients in group 2 (8.9/9.8 F Storz), and 576 patients in group 3 (6/7.5 F Wolf). SFR were 83.7%, 87.4%, and 92.2% in groups 1, 2, and 3, respectively (p=0.01). Duration of surgery was 30.34±10.36 min in group 1, 31.61±10.10 min in group 2, and 42.40±7.35 min in group 3 (p=0.01). The overall complication rates classified according to modified Satava classification were 10.8%, 7.6%, and 6.9% (p=0.01) while grade 3 modified Satava complication rates were 1.9%, 1.5%and 0.5% in groups 1, 2, and 3, respectively (p=0.01).

CONCLUSION

In this study, we found that more frequent use of a small- caliber URS resulted in a longer duration of surgery and an increased rate for JJ stent insertion, however it facilitated a safer and more successful ureteroscopy procedure.

A New Alternative for Difficult Ureter in Adult Patients: No Need to Dilate Ureter via a Balloon or a Stent with the Aid of 4.5F Semirigid Ureteroscope

OBJECTIVE

To investigate the effectivity of 4.5F ultrathin ureteroscope (UT-URS) without any need for active or passive dilation in the treatment of adult patient population in whom ureteral orifices cannot be engaged using conventional URS.

MATERIALS AND METHODS

Among a total of 512 adult patients who had undergone URS between April 2012 and November 2015 in our department for diagnostic or therapeutic purposes, 43 (8.4%) patients required ureteral dilation because we could not engage ureteral orifice. In adult patients in whom we could not engage ureteral orifice with 7.5F and 8F semirigid URS, we tried to complete the operation using 4.5F UT-URS without resorting to dilation. Age and gender of the patients, indication for operation, stone size, location, operative times, laterality of stone(s), stone-free rates, length of hospital stay, and complications were recorded.

RESULTS

Mean age of the patients was 34.5 ± 11.2 (21-66) years. The patients had undergone operations for ureteral stone (n = 39), unexplained hydronephrosis (n = 2), and ureteral stenosis (n = 2). Mean stone size was 8.2 ± 2.3 (4-18) mm. Mean operative time was 64.2 ± 13.5 minutes. In 37 of 39 patients, a complete stone-free rate (94.8%) was achieved. Mean length of hospital stay was 8.9 ± 5.8 hours.

CONCLUSION

It has been demonstrated that in an adult patient population in whom ureteral orifices cannot be engaged using conventional URS, ureteral access could be achieved with 4.5F UT-URS without any need for dilation. At the same time, use of 4.5F UT-URS resulted in an acceptable treatment success and lower complication rates in most of these patients without the need for a second session.

CUA Guideline: Management of ureteral calculi

The focus of this guideline is the management of ureteral stones. Specifically, the topics covered include: conservative management, medical expulsive therapy, active intervention with either shockwave lithotripsy (SWL) or ureteroscopy (URS), factors affecting SWL treatment success, optimizing success, and special considerations (e.g., pregnancy, urinary diversion). By performing extensive literature reviews for each topic evaluated, we have generated an evidence-based consensus on the management of ureteral stones. The objective of this guideline is to help standardize the treatment of ureteral stones to optimize treatment outcomes.