Results with 7.5F versus 10F rigid ureteroscopes in treatment of ureteral calculi

Do Stone Characteristics and Laser Fiber Size Affect Ho: YAG Laser Time and Energy During Ureteroscopy?

Objective

To assess the correlation of attenuation value measured as HU in Non-contrast computed tomography, stone size, location, fibre size and stone composition with Holmium: yttrium-aluminium garnet (Ho: YAG) laser parameters including, cumulative laser energy and final laser time.

Materials and Methods

 We prospectively analyzed 118 patients undergoing flexible/semirigid ureteroscopy and Holmium: YAG laser lithotripsy from October 2022 to October 2023 at Mogadishu Urological Centre. Our study parameters encompass preoperative stone characteristics determined in NCCT (stone size, attenuation value, and stone location), fibre size, cumulative laser energy and time, overall operative time, and postoperative stone composition analysis.

Results

There were 118 patients eligible for our prospective study. In the logistic regression model for retrograde intrarenal surgery with a fibre size of 272 μm, cumulative laser energy showed a significant difference among stone size, location, fibre size, and calcium oxalate stones (P > 0.05). However, no significant difference was noticed in the attenuation value (P = 0.078) (R2 = 0.053). Our analysis showed a positive significance among all the parameters (P < 0.05) for laser time. In logistic regression for a rigid ureteroscope with a fibre size of 365 μm, cumulative laser energy showed a significant difference between the location stone and fibre size (P < 0.05) (R2 = 0.09). However, no significant difference was seen among stone size, attenuation value, and calcium oxalate stones (P > 0.05). For laser time, our analysis showed a positive significance among all parameters except the calcium oxalate stones, which showed no significant difference (P > 0.05).

Conclusion

Our study showed that stone location, hardness, and fibre size are the most critical factors influencing the outcome of Ho: YAG laser parameters. The study revealed that CaOMH stones require more time to disintegrate into smaller ones, while PH-dependent stones such as carbonate apatite may require less time to fragment.

Peri-Ureteral Abscess Formation Following Ureteroscopic Laser Lithotripsy: A Case Report

We report the case of a patient with a previous history of obstructive renal calculus disease who initially presented with a symptomatic calculus in her right mid-ureter, requiring ureteroscopy with laser lithotripsy and ureteral stent placement. Shortly after the removal of the stent, the patient was found to have a peri-ureteral abscess, necessitating percutaneous drainage by interventional radiology, and placement of an additional ureteral stent. Adverse reactions to these procedures are rare and, to our knowledge, this is the only documented case of peri-ureteral abscess as a complication of ureteroscopic laser lithotripsy or of ureteral stenting. In addition to developing a peri-ureteral abscess, this patient also experienced deep vein thrombosis (DVT) and subsegmental pulmonary embolism (PE), which also have not been found to be a common complication of laser lithotripsy or ureteral stent placement in any of the studies that we reviewed for this article. The complications that were previously rare are unfortunately on the rise, possibly in the setting of both increased access to invasive therapies as well as the increased rates of diabetes and obesity. Survivability hinges on prompt recognition and treatment of these complications. In the event that a peri-ureteral abscess is discovered, prompt treatment with broad-spectrum antibiotics is recommended in addition to interventional radiology and urology consultation. Antibiotics should cover conventional intra-abdominal and urologic abscess regimens.

The effect of stone size on the results of extracorporeal shockwave lithotripsy versus semi-rigid ureteroscopic lithotripsy in the management of upper ureteric stones

Objectives

Patients and methods

Results

Conclusion

Ureteroscopic lithotripsy combined with paravertebral block anesthesia or general anesthesia: A propensity matched case-control study

BACKGROUND

To evaluate the safety, efficacy and cost of paravertebral block anesthesia for ureteral stones patients undergoing ureteroscopic lithotripsy.

METHODS

Four hundred and eighty-two patients who underwent ureteroscopy for unilateral ureteral stones were incorporated into our retrospective study. A propensity-matched comparison in patients with paravertebral nerve block anesthesia (PVB) group and general anesthesia (GA) group was performed. Intraoperative hemodynamic parameters, operative time, visual analog scale for pain, stone-free rate, anesthetic cost and postoperative hospital stay were compared between the two groups.

RESULTS

Sixty-one GA cases were propensity matched to 61 PVB cases. In the PVB group, all the procedures were completed successfully without anesthesia conversion. Significantly less intraoperative severe hypotensive (P = 0.002) and arrhythmia (P < 0.001) episodes in PVB group. There were no significant differences in operative time (p = 0.702), initial stone-free rate (p = 0.686), and total stone-free rate (p = 0.794) between the two groups. The PVB group had lower postoperative pain and prolonged analgesia (p = 0.007). The postoperative hospital stay in the PVB group was significantly shorter (3.20 ± 0.73 vs 3.84 ± 1.32 d, p = 0.001). And the cost of anesthesia was lower in the PVB group (195.47 ± 13.01 vs 396.31 ± 36.45 US dollars, p < 0.001).

CONCLUSION

Under PVB anesthesia, URS can be successfully completed without anesthetic transformation, and its efficacy and safety have been demonstrated. When economic aspects are taken into consideration, PVB seems to be a more economical and effective anesthetic method of URS.

Ureteric stenting vs not stenting following uncomplicated ureteroscopic lithotripsy: A prospective randomised trial

Objective

To compare three groups of patients who underwent uncomplicated ureteroscopic lithotripsy (URSL) and to evaluate whether stenting could be eliminated after the procedure, as there is no consensus about whether a ureteric stent should be placed after uncomplicated ureteroscopy for stone retrieval.

Patients and methods

In this randomised clinical trial (NCT04145063) 105 patients underwent uncomplicated URSL for ureteric stones. They were prospectively randomised into three groups: Group 1 (34 patients) with a double pigtail ureteric stent, Group 2 (35 patients) with a double pigtail ureteric stent with extraction string, and Group 3 (36 patients) with no ureteric stent placed after the procedure. The outcomes measured were: postoperative visual analogue scale (VAS) score for flank pain and dysuria score, urgency, frequency, suprapubic pain, haematuria, analgesia requirement, operative time, re-hospitalisation, and return to normal physical activity.

Results

The mean (SD) operative time was significantly longer in groups 1 and 2 compared to Group 3, at 22.2 (9.1), 20.2 (6) and 15.1 (7.1) min, respectively (P < 0.001). The results of the VAS for flank pain and dysuria scores, urgency, frequency, haematuria, and suprapubic pain showed a significant difference at all time-points of follow-up, being significantly higher in groups 1 and 2 compared to Group 3 (all P < 0.001). Further analysis showed that measured outcomes, and analgesia need for groups 1 and 2 were similar, at all time-points except at week 1 and 1 month where Group 2 patients’ had less symptoms (P < 0.001).

Conclusion

Double pigtail ureteric stent placement appears to be unnecessary in procedures considered ‘uncomplicated’ by operating urologists during surgery. The advantages of the double pigtail ureteric stent with extraction string over the double pigtail ureteric stent only include earlier and easier removal with earlier relief of symptoms, and less analgesia requirements.

Abbreviations

KUB: plain abdominal radiograph of the kidneys, ureters and bladder; URSL: ureteroscopic lithotripsy; VAS: visual analogue scale

Risk factors for ureteroscopic lithotripsy: a case-control study and analysis of 385 cases of holmium laser ureterolithotripsy

Introduction

Ureteroscopic lithotripsy has become the first choice for the treatment of middle and lower ureteral stones, but it still has a certain rate of surgical failure. Here we aimed to determine the factors that may affect the success rate of holmium laser ureterolithotripsy (HLU) and provide the basis and guidance for its future use.

Aim

To evaluate the risk factors for HLU failure.

Material and methods

The clinical data of 385 patients undergoing holmium laser ureterolithotripsy from 2009 to 2012 were retrospectively reviewed to analyze the impact of gender, age, stone side, stone size, stone location, stone number, degree of hydronephrosis, stone impaction, previous extracorporeal shock lithotripsy (ESWL), and associated urinary tract infection (UTI) on the success or failure of surgery.

Results

Surgical success was achieved in 338 (87.8%) patients versus surgical failure in 47 (12.2%) patients. Univariate analysis revealed that the degree of hydronephrosis (p = 0.024), stone impaction (p = 0.003), stone location (p = 0.012), and previous ESWL (p = 0.037) were risk factors for surgical failure. Multivariate logistic regression revealed that stone impaction (odds ratio (OR) = 2.66; p = 0.018) and stone location (OR = 2.11; p = 0.013) were significantly associated with surgical failure. Since some cases of ureterostenosis developed postoperatively, we continued follow-up. The patients had the stent for a year and underwent regular follow-up checks until 5 years. No cases of ureterostenosis recurred.

Conclusions

Ureteroscopic lithotripsy is a safe procedure with few complications. Stone impaction and proximal location are the risk factors for its failure.

Ureteral stricture after ureteroscopy for stones: A prospective study for the incidence and risk factors

Context:

A ureteral stricture is a serious complication of ureteroscopy (URS) that was reported in the literature in highly variable rates from 0.2% to 24%.

Aims:

Our aims are to estimate the incidence and to detect the risk factors of ureteral stricture after URS.

Settings and Design:

This is a prospective, case-series study.

Materials and Methods:

During the period from May 2015 to August 2016, 251 adult patients underwent 263 URS for the treatment of 304 ureteral stones. Postoperative regular follow-up was done for 12 months by ultrasound. Computed tomography urography and diuretic renogram were performed for the cases developed hydronephrosis to confirm and detect the level of the stricture.

Statistical Analysis:

IBM SPSS Statistics for Windows, Version 19.0, Armonk, NY: IBM Corp. used for data analysis. Chi-square and Fisher's exact tests were used to compare between qualitative variables. Mann–Whitney test was used to compare between two quantitative variables in case of nonparametric data. Multiple logistic regression analysis was done to measure the risk factors. P value was considered statistically significant when <0.05.

Results:

The mean age was 43.5 years (standard deviation [SD]: ±13.6), and the mean body mass index was 28.39 (±3.96). The mean total stone burden was 12.8 mm (SD: ±5.9). Bilateral URS was performed in 12 cases. The mean operative time was 54.8 min (SD: ±22.68). Initial and final stone-free rates were 83.3% and 100%, respectively. The overall complications rate was 28.1%. Stricture occurred in four cases (1.5%).

Conclusions:

In our experience, the incidence of post-URS ureteral stricture is low. The impacted stone is the most common cause of URS complications and hence stricture formation.

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.

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.

Do Outcomes of Percutaneous Nephrolithotomy in Horseshoe Kidney in Children Differ from Adults? A Single-Center Experience

OBJECTIVE

To compare the efficacy, outcome, and safety of percutaneous nephrolithotomy (PCNL) for stones in horseshoe kidney (HSK) in children compared with adults.

METHODS

We retrospectively reviewed data of 18 renal units in children (<15 years) and 26 renal units in adult patients with HSKs who underwent PCNL between March 2008 and June 2015.

RESULTS

Mean age of the study group was 25.92 ± 15.79 with adults having 36.12 ± 11.84 (range 20-65) and children having 10.32 ± 2.88 (range 5-15). Mean stone burden was 311.20 ± 203.99 (104-1080 mm(2)) with children of 211.13 ± 130.21 (104-500 mm(2)) and adults of 382.68 ± 219.27 (114-1080 mm(2)). Success rate is defined as either complete stone free or with asymptomatic and clinical insignificant residuals fragment of <3 mm on postoperative imaging. Initial success rate was 79.54% (86.61% in adults vs 72.22% in children). After auxiliary procedure, the final success rate is 93.18% (adults: 92.30% vs children: 94.44%). Overall complications noted in 12 cases with 23.07% in adults and 33.33% in children, most of them were minor complications.

DISCUSSION

There was no significant difference in initial and final success rate. Complication is slightly higher in children although statistically not significant. The outcomes and complications are similar to those reported in other studies of pediatric PCNL.

CONCLUSIONS

Outcomes in child and adult HSKs do not differ significantly with respect to success rate and complications. Children have a relatively smaller stone burden compared with adults with a similar distribution. We found that most of the puncture can be made infracostal in children as well as adults.

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.

Comparing the efficacy and safety of 365- and 550-μm laser fibers in semirigid ureteroscopic Ho:YAG lithotripsy

PURPOSE

To compare the efficacy and safety of 365- and 550-μm Ho:YAG laser fiber in semirigid ureteroscopic lithotripsy and to identify parameters that may affect laser energy and time during the procedure.

METHODS

A database of 111 patients who undergone a semirigid ureteroscopy (SRURS) for ureteral stone lithotripsy was analyzed. A 365-μm core fiber was used in 56 cases, and a multiple-uses 550-μm laser fiber was used in 55 cases. A standard 6.4 W protocol (8 Hz, 0.8 J/pulse) was used in all cases. The association between laser fiber diameter and several preoperative, intraoperative and postoperative parameters was evaluated.

RESULTS

Mean stone burden was 54.1 ± 39.1 mm(2), and postoperative stone-free and complication rate was 100.0 and 16.2 %, respectively. The 550-μm laser fiber diameter was significantly associated with lower laser energy (p = 0.01), energy/mm(3) (p = 0.031), number of pulses (p = 0.012), laser time (p = 0.012) and laser time/mm(3) (p = 0.043), while it did not affect postoperative outcomes. The multivariate analysis showed that shorter procedure duration, smaller stone burden and the 550-μm laser fiber were all significant independent predictors for decreased laser energy consumption.

CONCLUSION

The 550-μm laser fiber may decrease laser energy and time during SRURS lithotripsy with Ho:YAG laser compared to the 365 μm. Given its lower cost, it may represent the optimal choice for semirigid procedures.

Are Adult Ureteroscopes Safe in the Management of Urolithiasis in a Pediatric Population?

INTRODUCTION

Debate remains regarding the optimal caliber of ureteroscopes in the management of pediatric urolithiasis, ranging from pediatric scopes to standard scopes. The aim of this study was to assess the safety and efficacy of stone management in a pediatric population using standard adult ureteroscopes.

METHODS

A retrospective review of all ureteroscopic procedures in patients under the age of 16 years was carried out. Standard adult 7.5 French semi-rigid and 6 French flexible ureteroscopes were used.

RESULTS

During the study period, 8 patients underwent 21 ureteroscopic procedures. Two patients had rigid ureteroscopy, seven had flexible ureterorenoscopy and one had a subsequent open procedure. No patients required ureteric dilation. Double J ureteric stents were utilized in 7 patients. There were no complications. All patients required extra corporeal shock wave lithotripsy. Stone clearance was achieved in all patients.

CONCLUSION

Our series demonstrates that, in skilled hands, adult ureteroscopes can be use safely for the treatment of urolithiasis in pediatric patients.

Reporting ureteroscopy complications using the modified clavien classification system

Objective:

Perioperative complications are one of the surrogate indicators of surgical outcomes. However, reporting these complications need a precise grading system. Our aim is to report and grade the complications of semirigid ureteroscopy in ureteral stone management according to the modified Clavien classification system.

Materials and Methods:

This is a prospective study conducted From January 2012 to June 2013. All patients with ureteral stones who were indicated for semirigid URS were evaluated. All procedures were performed by the same surgeon. The data recorded including patient demographics, clinical indication, stone size and location, operative time and complications were classified according to the modified Clavien classification system. The patients were followed for 8 weeks postoperatively.

Results:

148 patients included, Stone distribution was: 89 (60.1%) lower ureteral, 26 (17.6%) mid ureteral, and 33 (22.3%) upper ureteral. the mean stone size was 8.6 mm. Urgent URS done in 23% of patient. The overall stone free rate was 88.5%, the individual stone free rate for the upper, middle and lower ureter were 87.9%, 84.6%, and 89.9%, respectively. The mean operative time was 31.9 min (20-50 min.). Complications occurred in 26.35% of patients. Grade I complications occurred in 32 patients (26.1%), grade II in 9 (6.1%), grade IIIa in 7 (4.7%), grade IIIb in 8 (5.4%), grade IVa in two patient (1.35%), and grade IVb in one patient (0.7%). No grade V complication was encountered.

Conclusion:

Ureteroscopy becomes the vanguard interventional therapy for ureteral stones with well-established efficacy and safety. It is of paramount importance to adopt a precise structured classification system for reporting surgical complications, that should be flexible and comprehensive in order to accommodate the various and rapidly expanding surgical fields.

Determinants of holmium:yttrium-aluminum-garnet laser time and energy during ureteroscopic laser lithotripsy

OBJECTIVE

To evaluate the association of preoperative noncontrast computed tomography stone characteristics, laser settings, and stone composition with cumulative holmium:yttrium-aluminum-garnet (Ho:YAG) laser time/energy.

MATERIALS AND METHODS

We retrospectively reviewed patients who underwent semirigid/flexible ureteroscopy and Ho:YAG laser lithotripsy (200 or 365 μm laser fiber; 0.8-1.0 J energy; and 8-10 Hz rate) at 2 tertiary care centers (April 2010-May 2012). Studied parameters were as follows: patient's characteristics; stone characteristics (location, burden, hardness, and composition); total laser time and energy; and surgical outcomes.

RESULTS

One hundred patients met our inclusion criteria. Mean stone size was 1.01 ± 0.42 cm and volume 0.33 ± 0.04 cm(3). Mean stone radiodensity was 990 ± 296 HU, and Hounsfield units density 13.8 ± 6.0 HU/mm. All patients were considered stone free. Stone size and volume had a significant positive correlation with laser energy (R = 0.516, P <.001; R = 0.621, P <.001) and laser time (R = 0.477, P <.001; R = 0.567, P <.001). When controlling for stone size, only the correlation between HU and laser time was significant (R = 0.262, P = .011). In the multivariate analysis, with exception of stone composition (P = .103), all parameters significantly increased laser energy (R(2) = 0.524). Multivariate analysis revealed a positive significant association of laser time with stone volume (P <.001) and Hounsfield units density (P <.001; R(2) = 0.512). In multivariate analysis for laser energy, only calcium phosphate stones required less energy to fragment compared with uric acid stones. No significant differences were found in the multivariate laser time model.

CONCLUSION

Ho:YAG laser cumulative energy and total time are significantly affected by stone dimensions, hardness location, fiber size, and power. Kidney location, laser fiber size, and laser power have more influence on the final laser energy than on the total laser time. Calcium phosphate stones require less laser energy to fragment.

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.

Does stone entrapment with ″Uro-Net″ improve Ho:YAG laser lithotripsy efficiency in percutaneous nephrolithotomy and cystolithopaxy?: an in vitro study

PURPOSE

to test the effect of stone entrapment on laser lithotripsy efficiency.

MATERIALS AND METHODS

Spherical stone phantoms were created using the BegoStone® plaster. Lithotripsy of one stone (1.0 g) per test jar was performed with Ho:YAG laser (365 µm fiber; 1 minute/trial). Four laser settings were tested: I-0.8 J,8 Hz; II-0.2J,50 Hz; III-0.5 J,50 Hz; IV-1.5 J,40 Hz. Uro-Net (US Endoscopy) deployment was used in 3/9 trials. Post-treatment, stone fragments were strained though a 1mm sieve; after a 7-day drying period fragments and unfragmented stone were weighed. Uro-Net nylon mesh and wire frame resistance were tested (laser fired for 30s). All nets used were evaluated for functionality and strength (compared to 10 new nets). Student's T test was used to compare the studied parameters; significance was set at p < 0.05.

RESULTS

Laser settings I and II caused less damage to the net overall; the mesh and wire frame had worst injuries with setting IV; setting III had an intermediate outcome; 42% of nets were rendered unusable and excluded from strength analysis. There was no difference in mean strength between used functional nets and non-used devices (8.05 vs. 7.45 lbs, respectively; p = 0.14). Setting IV was the most efficient for lithotripsy (1.9 ± 0.6 mg/s; p < 0.001) with or without net stabilization; setting III was superior to I and II only if a net was not used.

CONCLUSIONS

Laser lithotripsy is not optimized by stone entrapment with a net retrieval device which may be damaged by high energy laser settings.

Comparison of a 4.5 F semi-rigid ureteroscope with a 7.5 F rigid ureteroscope in the treatment of ureteral stones in preschool-age children

The aim of this study was to compare the success and complication rates of a 4.5 F ureteroscope with a 7.5 F ureteroscope in the treatment of urolithiasis in preschool-age children. We retrospectively reviewed 69 ureteroscopy (URS) procedures in a pediatric population (40 boys, 29 girls). We divided the patients into two groups according to the type of ureteroscope used: group 1 (n = 42, Storz 7.5 F) and group 2 (n = 27, Wolf 4.5 F). We statistically compared all the procedures performed in both groups regarding patient age, complication rates, whether the procedure was therapeutic, and whether we used a guidewire. Additionally, in cases with ureteral stones, we also compared the stone clearance rate and the necessity of X-ray imaging between the two groups. The mean patient age was 56.04 months in group 1 and 47.48 months in group 2 (p = 0.057). The stone-free rate was 78.6 % in group 1 and 92.6 % in group 2 (p > 0.05). However, when we compared the stone-free rates for patients younger than 3 years, the rate was 66.7 % in group 1 and 93.8 % in group 2 (p < 0.05). The difference was not statistically significant for patients between the ages of 4 and 7 years. The success and failure rates revealed better outcomes for treatment of ureteral stones with a 4.5 F ureteroscope. We recommend the use of the mini-ureteroscope, especially in infants and preschool-age children.

Minimally Invasive Surgical and Medical Management of Urinary Calculi

Management of urinary calculi has changed from open pyelolithotomy and ureterolithotomy to predominantly non-invasive procedures such as extracorporeal shockwave lithotripsy (ESWL) as well as endourological such as ureterorenoscopy (URS) and percutaneous nephrolithotripsy (PCNL). Technology has advanced rapidly allowing stone disease to be treated with minimally invasive techniques that have lower morbidity than the open operations of the past. Newer semi-rigid ureteroscopes of size 7 to 9 F allow visualisation of the ureter without traumatic dilatation. There is the flexible ureteroscope developed with smaller fibre optics, the addition of the working channel that allows the use of laser fibres for stone fragmentation and a greater deflection of the tip that enables all parts of the pelvicalyceal system to be inspected for stones. New generation lithotripters for ESWL deliver shockwave to a smaller focal zone so as to minimise damage to surrounding soft tissue but as a result, there are higher failure rates. PCNL, though more invasive than ESWL and URS, is the procedure of choice for large renal stones. It is highly efficient in such situations as newer equipment to disintegrate stone and newer techniques for percutaneous access has been developed. In addition to all these minimally invasive surgical techniques, there is medical therapy available to allow the expulsion of distal ureteric stones as well as alkalinising agents to dissolve uric acid stones. Metabolic evaluation is necessary for patients with recurrent stones. Dietary adjustments may help prevent recurrent stone formation in selected patients depending on the results. With all these techniques currently available, management of urinary calculi has to be tailored according to the size, location of stone as well as patient preference.

Is a safety wire necessary during routine flexible ureteroscopy?

BACKGROUND AND PURPOSE

The use of flexible ureteroscopy (URS) for nephrolithiasis has been rapidly expanding. Initially, safety guidewires were maintained alongside the ureteroscope during stone manipulation to prevent loss of access and allow stent insertion in the event of perforation. We intend to determine the safety of flexible URS without a separate safety guidewire in a large series of patients.

METHODS

A retrospective chart review was performed on all cases of flexible URS with laser lithotripsy performed by a single surgeon from August 2003 to May 2008. Preoperative patient characteristics, radiographic stone sizes, operative findings, and postoperative outcomes were recorded. Patients with renal or ureteropelvic junction (UPJ) stones were isolated for a qualitative data analysis.

RESULTS

Flexible URS was performed on 305 kidneys in 246 consecutive patients, of which 59 cases were bilateral. Cases were subdivided into complicated and uncomplicated. Two hundred seventy cases were uncomplicated and performed without a safety guidewire. No intraoperative complications resulted from the lack of a safety guidewire, including no cases of lost access, ureteral perforation/avulsion, or need for percutaneous nephrostomy tube. Thirty-five cases were complicated, necessitating a safety guidewire. Of these, 16 had concomitant obstructing ureteral stones, 5 had encrusted ureteral stents, and 14 had difficult access because of large stone burden or aberrant anatomy.

CONCLUSIONS

This study demonstrates that, in a large series of patients, a safety guidewire was not necessary for routine cases of flexible URS with laser lithotripsy on renal or UPJ stones. Particular cases with complicated anatomy, difficult access, concomitant ureteral stones, simultaneous stone basketing, or bulky stone burden still necessitate use of a safety guidewire because of increased risk of adverse outcomes.

Semirigid ureteroscopy in management of large proximal ureteral calculi: is there still a role in developing countries?

OBJECTIVES

To evaluate the outcome and complications of the use of semirigid ureteroscopy (URS) together with intracorporeal pneumatic lithotripsy in the management of upper ureteral calculi >10 mm in diameter.

METHODS

A total of 75 patients (41 women and 34 men), with a mean age of 48 years (range 25-60), underwent primary URS for solitary radiopaque proximal ureteral calculi 10-20 mm in diameter (average 13.1). Dilation of the intramural ureter was done in 60 cases (80% of patients), and intracorporeal lithotripsy was required in 56 (74.6%). Ureteral catheters were left for drainage in 60% of patients, 26.7% were left unstented, and only 13.3% required an indwelling stent.

RESULTS

Of the 75 stones, 60 (80%) were successfully cleared after a single endoscopic procedure. Our initial stone-free rate was 90.6% at 2 weeks after the primary endoscopic procedure and had reached 98.6% at 3 months. Antegrade URS for migrating stones was done successfully in 6 cases in a tubeless fashion, and open ureterolithotomy was required in 1 case. No major complications were encountered. The minor complications included only mild extravasation and self-limited postoperative fever and hematuria. The risk factors for URS failure included male gender, the severity of the hydronephrosis, the severity of impaction, and the occurrence of extravasation.

CONCLUSIONS

The results of our study have shown that semirigid URS is a safe and successful alternative to open ureterolithotomy in the management of large proximal ureteral calculi in the absence of flexible instruments.

Comparison of ureteroscopic procedures with rigid and semirigid ureteroscopes in pediatric population: does the caliber of instrument matter?

OBJECTIVES

To compare the results of two different ureteroscopes in pediatric ureteroscopy (URS) procedures.

PATIENTS AND METHODS

Sixty-five consecutive URS procedures in pediatric population (39 males, 26 females) were retrospectively evaluated. The subjects were divided in two groups according to the type of ureteroscope used: Group 1 (n = 32, Wolf 8F) and group 2 (n = 33, ACMI 6.9F). All the procedures performed in both groups were statistically compared regarding patient age, gender, lateralization, complication rates, whether the procedure was diagnostic or therapeutic, and whether a guide-wire was used. Additionally, in cases with ureteral stones, stone clearance rate and the necessity of a stone extractor were also compared between the groups. All data were statistically analyzed using chi-square and t tests, where appropriate. A p value less than 0.05 was considered as significant.

RESULTS

Mean age of the groups were comparable (9.44 +/- 4.3 and 8.67 +/- 3.9, p = 0.456). There was no statistically meaningful difference between the groups regarding patients' gender, lateralization rates, whether the procedure was diagnostic or therapeutic, the need for a guide-wire use, and complication rates (p > 0.05). In cases with ureteral stones, both groups exhibited statistically comparable results in stone clearance rates and the use of a stone extractor (p > 0.05).

CONCLUSIONS

Data on this comparison demonstrated that both ureteroscopy devices in pediatric population can be used safely in URS procedures. Neither the diameter nor the rigidity is significantly affecting the outcomes and success rates <or=8F caliber.

A prospective randomized study comparing shock wave lithotripsy and semirigid ureteroscopy for the management of proximal ureteral calculi

OBJECTIVES

To conduct a prospective randomized study comparing both techniques for the management of solitary radio-opaque upper ureteral stones < 2 cm in diameter. The ideal treatment for upper ureteral stones > 1 cm size remains to be determined with shock wave lithotripsy (SWL) and ureteroscopy (URS) being acceptable options.

METHODS

A total of 200 patients were included in the study. They were randomized into 2 equal groups. Group A underwent in situ SWL as a primary therapy. Group B underwent URS, using semirigid URS with intracorporeal lithotripsy. Efficiency quotient (EQ), cost analysis, and predictors of failure were estimated for both techniques.

RESULTS

For stones of size > or = 1 cm, the initial stone-free rate for URS and SWL was 88% and 60%, respectively. The estimated EQ was 0.79 and 0.43 for both techniques respectively. For stones < 1 cm, the initial stone-free rate for URS and SWL was 100% and 80%, respectively. The estimated EQ was 0.88 and 0.70 for both techniques, respectively. The mean cumulative costs were significantly more in SWL group (P <.05). Predictors of URS failure included; male gender, failure to pass guidewire beyond the stone, and extravasation. Predictors of SWL failure included large stone size > 1 cm, calcium oxalate monohydrate stone, and higher degrees of hydronephrosis.

CONCLUSIONS

URS with intracorporeal lithotripsy is an acceptable treatment modality for all proximal ureteral calculi, particularly stones > 1 cm. SWL should remain the first-line therapy for proximal ureteral calculi < or = 1 cm because of the less invasive nature and lower anesthesia (i.v. sedation).

Experience with impacted upper ureteral stones; should we abandon using semirigid ureteroscopes and pneumatic lithoclast?

Introduction

The AUA/EAU Ureteral Stones Guideline Panel reported that the stone free rate for the proximal ureteral stones is around 81% when treated by either SWL or ureteroscopy (URS).

Complication rates, most notably ureteral perforation and long-term complications of URS such as stricture formation rates, have been reduced to < 5%. Moreover, impacted ureteral calculi are more difficult to fragment with SWL because of the lack of natural expansion space for stones, this result in a situation that is better managed by ureteroscopy. The aim of this study is to assess the efficacy, safety, and complications of impacted upper ureteral stone disintegration using semirigid ureteroscopes and pneumatic lithotripsy.

Methods

We retrospectively analyzed the records of 267 consecutive patients with impacted upper ureteral stones (9–20 mm) who were treated by semirigid ureteroscopes and pneumatic disintegration. The efficacy of treatment was estimated using the stone-free rate and all treatment related complications were analyzed.

Results

Except for 24 cases where the stone migrated to the kidney, the stone was successfully treated ureteroscopically, with a low rate of minimal complications such as mild hematuria (18.4%), short term low grade fever (13.5%). Only 3 patients (1.1%) had high grade fever and none had post operative stricture.

Conclusion

The use of semirigid URS and pneumatic lithotripsy in impacted upper ureteral stones in experienced hands has very satisfactory results with minimal complications. When Holmium laser and flexible URS are not available, semirigid URS and pneumatic lithotripsy is a good alternative that shouldn't, yet, be abandoned.

Semirigid ureteroscopy for ureteral stones: a multivariate analysis of unfavorable results

PURPOSE

We determined the factors predicting unfavorable results of semirigid ureteroscopy for ureteral calculi.

MATERIALS AND METHODS

We reviewed the computerized files of 841 patients who underwent a total of 908 ureteroscopic procedures for ureteral stones from January 2003 through December 2006. A semirigid 6/7.5Fr ureteroscope was used in pediatric patients and an 8/10Fr or 8.5/11.5Fr ureteroscope was used in adults. Patients with favorable results were those who became stone-free after a single ureteroscopic procedure without any complications. They were compared with patients who had unfavorable results using univariate (chi-square and t tests) and multivariate (logistic regression) statistical tests to identify risk factors for unfavorable results.

RESULTS

The study included 567 males and 274 females with a mean age of 48.5 years (range 2 to 81). The complication rate was 6.7% (61 procedures). The stone-free rate after a single ureteroscopic intervention was 87% (791 procedures). Favorable results were documented in 751 procedures (82.7%). Significant factors for unfavorable results were proximal ureteral stones, ureteroscopy done by surgeons other than experienced endourologists, stone impaction and stone width (relative risk 4, 2.5, 1.8 and 1.2, respectively).

CONCLUSIONS

Semirigid ureteroscopy is a safe and highly effective treatment modality for ureteral stones.