Flexible ureteroscopy: Washington University experience with the 9.3F and 7.5F flexible ureteroscopes

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.

Controversies in ureteroscopy: Wire, basket, and sheath

In the last one to two decades, flexible ureteroscopy has rapidly expanded its role in the treatment of urologic stone disease. With the frequent and expanded use of flexible ureteroscopy, other ancillary instruments were developed in order to ease and facilitate this technique, such as ureteral access sheaths (UAS) and a variety of wires and baskets. These developments, along with improved surgeon ureteroscopic competence, have often brought into question the need to implement the “traditional technique” of flexible ureteroscopy. In this review, we discuss a brief history of flexible ureteroscopy, its expanded indications, and the controversy surrounding the use of UAS, wires, and baskets.

Improving flexible ureterorenoscope durability up to 100 procedures

BACKGROUND AND PURPOSE

Controversy exists in the literature regarding flexible ureterorenoscopy (F-URS) durability, with a variable expected number of uses from a new F-URS. In this study, a tertiary center experience with the use of two consecutive F-URS is reported and suggestions as to how to improve durability further are made.

MATERIALS AND METHODS

All F-URS performed in the same tertiary care center between July 2009 and February 2011, with two new instruments Flex-X, were reviewed retrospectively. All renal pathology were included. Ureteral cases were excluded. A 9.5F semirigid ureteroscope was always used at the start for a ureteral optical predilation and to explore the upper urinary tract for possible lithotripsy/laser ablation/biopsy. The F-URS was introduced sequentially to explore the remaining calices. Data pertaining to the procedure were collected. The method of sterilization was complete immersion with Cidex®.

RESULTS

The instruments were substituted after 113 and 102 procedures, respectively. The first F-URS was used for a total operative time of 79 hours and 10 minutes while the second one was used for 71 hours and 25 minutes (mean 75 hours and 15 min). Procedure duration was 15 to 175 minutes (mean 58 min). The flexible instruments were used for a mean of 42 minutes per procedure (range 13-153 min). The indications for F-URS were therapeutic in 75.4% and diagnostic in 22.8% of the cases. For lower pole calculi, the stone was relocated in 65.2% and managed with the nonflexed flexible instrument 90% of the time. The most common causes of damage of F-URS were: Deflection mechanism impairment, inner sheath damage, and fiberoptic bundle breaks.

CONCLUSIONS

Increased durability of F-URS was from a variety of factors, a key element of which was the method of sterilization, while routine use of the semirigid instrument initially further contributed significantly to increase the number of F-URS procedures, saving overall costs.

Flexible ureteroscopy and laser lithotripsy for bilateral multiple intrarenal stones: is this a valuable choice?

OBJECTIVE

To demonstrate the safety and efficacy of flexible ureteroscopy (FURS) and holmium laser lithotripsy as a valuable treatment of bilateral multiple intrarenal stones and stratify the efficacy by stone burdens ≤ 20 and >20 mm.

METHODS

Twenty-five patients with bilateral multiple intrarenal stones were treated with FURS and holmium lithotripsy at a single clinic. The operative time, stone-free rates (SFRs) per renal unit, stone compositions, number of procedures, serum creatinine, and complications were evaluated. The SFRs were evaluated with computed tomography and plain X-rays of the kidneys, ureters, and bladder. Renal ultrasound was performed 30 days after double-J stent removal to identify hydronephrosis and absence of stones. We defined a stone-free status as the absence of fragments in the kidney or fragments of <1 mm.

RESULTS

The total stone number was 128 with a mean stone burden per patient of 24 ± 5 (range 17-37 mm). The overall SFRs per renal unit after 1, 2, and 3 procedures were 70.0%, 92.0%, and 92.0%, respectively. The overall SFRs per renal unit for patients with a preoperative stone burden ≤ 20 and >20 mm were 100% and 85.7%, respectively. No major intraoperative or postoperative complications occurred. There were only 4 minor postoperative complications (16%).

CONCLUSION

Our study results firmly suggest that FURS with holmium laser lithotripsy represents a favorable alternative to external shock wave lithotripsy or percutaneous nephrolithotomy for select patients with bilateral multiple intrarenal stones, which have a satisfactory efficacy and low morbidity.

Narrow-band imaging digital flexible ureteroscopy in detection of upper urinary tract transitional-cell carcinoma: initial experience

PURPOSE

To characterize the appearance of normal and malignant upper urinary tract lesion appearance under narrow-band imaging (NBI) using the new URF-V digital flexible ureteroscope (DFU), and to determine if NBI, when used in conjunction with white light (WL), could improve detection of malignancy.

PATIENTS AND METHODS

NBI and WL were performed in 27 patients at our university teaching hospital, 14 with known cases of upper urinary tract transitional-cell carcinoma (UUT-TCC) as follow-up (group A), and 13 patients with first-suspicion of cancer (group B). Full renal collecting system examination was performed first under WL and then under NBI by a single urologist. Biopsies were taken from all detected lesions using the biopsy forceps and sent for examination by a pathologist who was blinded to the gross description of the lesion. Pathology interpretations were then compared with the corresponding WL and NBI images. Holmium laser vaporization was performed for all apparent lesions.

RESULTS

Subjectively, NBI significantly improved the endoscopic visualization of the tumors, providing a detailed description of their limits and vascular architecture. Objectively, five additional tumors (14.2%) in four patients, as well the extended limits of three tumors (8.5%) in three patients were detected by NBI when findings by WL imaging were considered normal.

CONCLUSION

This is one of the first reports regarding NBI for UUT-TCC. From this study, we recommend this technology as a valuable diagnostic method, because it considerably improves tumor detection rate by 22.7% compared with WL.

O valor da fase sem contraste na tomografia computadorizada do abdome

OBJETIVO: Determinar o valor agregado da fase sem meio de contraste da tomografia computadorizada do abdome em pacientes sem diagnóstico determinado ou em estadiamento tumoral. MATERIAIS E MÉTODOS: Estudo prospectivo e transversal em 100 pacientes consecutivos submetidos a tomografia computadorizada abdominal sem e com meio de contraste intravenoso. Dois examinadores avaliaram todos os exames, procurando estabelecer, através da fase com meio de contraste intravenoso (primeira análise) e posteriormente através da fase sem contraste (segunda análise), o diagnóstico principal e os secundários em função da indicação clínica do exame. Mediu-se a freqüência de mudança diagnóstica decorrente da análise combinada das fases pré- e pós-contraste intravenoso. Casos que tiveram mudança diagnóstica foram avaliados por especialistas clínicos para determinar se implicaria mudanças de conduta. RESULTADOS: Diagnósticos principal e secundário foram modificados em 1 e 18 casos, respectivamente (p = 1,000; p = 0,143). Os diagnósticos modificados foram: esteatose, definição de nódulo em adrenal, nefrolitíase, classificação de cistos renais e calcificação hepática. Nos casos em que a fase sem contraste modificou o diagnóstico, os especialistas mudaram sua conduta em 14/19 (73%) dos pacientes (p = 0,038). CONCLUSÃO: A fase sem contraste não modificou significativamente o diagnóstico principal ou secundário. Porém, as mudanças nos diagnósticos secundários influenciaram na conduta adotada pelos especialistas.

Flexible ureteroscopy and laser lithotripsy for multiple unilateral intrarenal stones

BACKGROUND

External shock wave lithotripsy (ESWL) and percutaneous nephrolithotomy (PNL) have been the standard of care for the treatment of intrarenal calculi.

OBJECTIVE

We sought to determine the safety and efficacy of flexible ureteroscopy and holmium laser lithotripsy for the treatment of multiple intrarenal calculi and further stratify the efficacy by stone burden less than and greater than 20mm.

DESIGN, SETTING, AND PARTICIPANTS

Patients with multiple unilateral renal calculi treated between 2000 and 2006 at a single tertiary academic center were retrospectively evaluated.

INTERVENTION

All patients underwent retrograde flexible ureteroscopy and holmium laser lithotripsy.

MEASUREMENTS

Stone-free status was determined by ureteroscopy 15 d after the last procedure and was defined as the absence of stones in the kidney or residual fragments <1mm. A renal ultrasound was performed 30 d after the last treatment to confirm the absence of stones and hydronephrosis.

RESULTS AND LIMITATIONS

Fifty-one patients were identified for a total of 161 intrarenal calculi with a mean stone size per patient of 6.6+/-3mm (range: 2-15). The mean number of stones per patient was 3.1+/-1 (range: 2-6). The mean number of primary procedures was 1.4+/-0.6 (range: 1-3). The overall stone-free rates after one and two procedures were 64.7% and 92.2%, respectively. The stone-free rates for patients with a stone burden greater than and less than 20mm were 85.1% and 100%, respectively. The overall complication rate was 13.6%; 97.6% of cases were performed as outpatient procedures. There are some limitations to this study, however: This is a retrospective review from a single institution, and our results are based on a relatively small sample size.

CONCLUSIONS

For select patients with multiple intrarenal calculi, flexible ureteroscopy with holmium laser lithotripsy may represent an alternative therapy to ESWL or PNL, with acceptable efficacy and low morbidity.

FlexGuard: a new laser insertion sheath: functional aspects in ureterorenoscopy (URS)

The evolution of flexible ureteroscopes led to a widespread use for the management of upper urinary tract abnormalities. The cost of purchase, maintenance and the durability of these instruments has become a major issue. This work describes a new device to avoid damages due to incorrect use of the Holmium laser during insertion of the laser fibre. A laser fibre with an optical core of 271 and 430 muicrom outside diameter was slid inside the FlexGuard laser fibre insertion sheath (LISA laser products, Germany). The outside diameter of the sheath measures 2.7 F (0.9 mm) and 2.1 F (0.7 mm) luminal diameter. The distal fibre tip was brought up to a position app. 2 mm inside the distal end of the sheath. The loaded sheath was pushed through the working channel of various ureteroscopes which were in maximum deflection. With the insertion sheath protruding about 2 mm from the distal tip of the URS the fibre was effortless forwarded out of the sheath to approach the stone. Once the laser fibre was in position, the sheath was removed, to increase the volume of irrigation fluid during laser lithotripsy. The radius of curvature (ROC) of the URS in maximum deflection and the integrity of the working channel was investigated. Using the insertion sheath the laser fibre reached the working position without any recognition of scratching or resistance. The integrity of the ureterorenoscopes was checked thoroughly be manually operated manometry. No damage of the inner surface of the working channel occurred. The ROC of the instrument did not change significantly during this procedure. After removal of the sheath the ROC remained stable. With the extended use of ureteroscopy, durability and repair costs are of concern. Damage resulting from incorrect use of laser fibres is a major issue in this respect. FlexGuard proved to avoid this damage in all flexible ureteroscopes investigated without limiting their mobility.

Frequency of ureteroscope damage seen at a tertiary care center

PURPOSE

There is controversy regarding ureteroscope durability. Little is known regarding the subsequent durability of a flexible ureteroscope after major damage has been incurred and the ureteroscope has been repaired. Maintenance and repair are associated with significant cost. We reviewed and assessed the frequency and cause of ureteroscope damage at our medical center.

MATERIALS AND METHODS

From December 2001 we prospectively recorded the specific use of all ureteroscopes and any resultant damage at a single tertiary care institution. We then reviewed a total of 601 ureteroscopic cases involving 654 semirigid and flexible ureteroscope uses from December 2001 to November 2004. Cases were performed by multiple residents and fellows under the supervision of 3 attending urologists (CML, RJL and VGB). Retrograde and antegrade cases involving stones, urothelial carcinoma, strictures and diagnostic evaluations were included. Repairs for the respective ureteroscopes were performed by the original manufacturer.

RESULTS

A total of 53 reports of damage (8.1% of total uses) were recorded. Major damage when the scope was deemed unusable and required repair was seen in 39 cases (6.0%). Four newly purchased flexible ureteroscopes were entered into the study and they provided 40 to 48 uses before the initial repair was needed. After these new ureteroscopes underwent comprehensive repair for major damage they averaged only 11.1 uses (median 8) before needing repair again. Older model ureteroscopes that underwent repair before being entered into our study averaged between 4.75 and 7.7 uses before being sent for subsequent repair. Of the total of 39 breakages 39 for which ureteroscopes were sent for repair 14 (35.9%) were the result of errant laser firing, 11 (28.2%) were the result of excessive torque, 8 (20.5% 8) were the result of decreased flexion in the distal tip or another loss of function without obvious iatrogenic cause, 3 (7.7%) were the result of multifocal catastrophic damage involving laser firing and excessive torque, and 3 (7.7%) were the result of cleaning and processing outside of the ureteroscopy suite.

CONCLUSIONS

The most important risk factors for predicting the number of uses expected from a ureteroscope at our institution is ureteroscope age and whether the ureteroscope has undergone comprehensive repair as the result of prior damage. Our analysis suggests that after damage occurs to a ureteroscope more damage occurs with greater frequency. The cost of maintaining previously used ureteroscopes should be carefully considered in comparison to the cost of purchasing a new ureteroscope.

New-generation flexible ureterorenoscopes are more durable than previous ones

OBJECTIVES

To determine the deterioration in the maximal active deflection and flow capabilities of a new-generation flexible ureteroscope (URS).

METHODS

We performed 50 ureterorenoscopies using the same URS: a Karl Storz 11278 AU1 Flex-X, which is capable of a 270 degree active deflection in the ventral and dorsal directions. Postoperatively, we evaluated the maximal active ventral and dorsal deflection, irrigation flow at 100 cm H2O, and the number of broken optical fibers.

RESULTS

The URS was used for a total of 76 hours, 15 minutes (average 95 minutes per procedure). The maximal ventral deflection had deteriorated from 270 degrees to 208 degrees at the last procedure. The maximal dorsal deflection had decreased from 270 degrees to 133 degrees. The irrigation flow at 100 cm H2O had decreased from 50 mL/min initially to 40 mL/min at the last procedure. The number of broken image fibers had reached six at the 50th procedure. One repair was necessary at the 50th procedure because of a laser perforation of the working channel.

CONCLUSIONS

The need for repair occurs less frequently with the new-generation of URSs, especially when they are used by an experienced endourologist. In the future, improvements in the durability of the flexible URS will still be key for widespread use of the technique and especially to limit damage by the laser to the working channel.

Ureterorenoskopie (URS) bei Harnsteinen

Distal ureteral calculi (<5 mm) usually pass the ureter spontaneously. Ureteroscopic lithotripsy of distal ureteral calculi shows high stone-free rates with a low complication rate (4%) and is equal to extracorporeal shock wave lithotripsy (ESWL), while ESWL is the primary choice for proximal ureteric stones. Flexible endoscopes are more difficult to handle and should be used only under fluoroscopic control. They are generally used in combination with the holmium:YAG laser and the flexible Lithoclast in the proximal ureter or the renal collecting system. Overall the complication rate of URS is 9-11% with avulsion of the ureteric urothelium being the most common complication. Ureteral perforation, stricture (<1%), impaction of the instrument in the ureter with consequent ureteral laceration, extravasation of stones, and bleeding in the urogenital tract are complications of URS but are minimal in the hands of a well-trained and skilled surgeon.

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

OBJECTIVES

To compare the success and complication rates in the treatment of ureteral stones with a 7.5F versus a 10F ureteroscope.

METHODS

A total of 100 patients who were scheduled for ureteroscopy to treat ureteral calculi between December 2000 and December 2002 were randomly assigned to procedures with a 7.5F (group 1; n = 50) or 10F (group 2; n = 50) ureteroscope. The group results were compared.

RESULTS

Group 1 had 36 distal, 9 middle, and 5 proximal ureteral stones. Group 2 had 37 distal, 6 middle, and 7 proximal ureteral stones. No statistically significant differences were noted between the two groups with respect to the mean stone size or operation time (P = 0.175 and P = 0.636, respectively). Pneumatic lithotripsy was used in 62% and 50% of the procedures in group 1 and 2, respectively, and stones or fragments were retrieved with basket catheters in 92% and 76% of the group procedures, respectively. The difference between the group rates for successful basket catheter extraction was statistically significant (P = 0.029). Of the patients in group 1 and 2, 84% and 80%, respectively, were stone free after a single procedure (P = 0.603). The corresponding failure rates in the two groups were 6% and 12% (P = 0.295), and the corresponding early and late complication rates in the two groups were 6% and 4% (P = 0.646). None of the patients in group 1 developed late complications. One individual (2%) in group 2 developed ureteral stenosis during long-term follow-up (P = 0.315).

CONCLUSIONS

The success and failure rates revealed better outcomes for treatment of ureteral calculi with a 7.5F ureteroscope, but the differences were not statistically significant. The complication rates were similar between the two groups. Basket catheters were used more frequently with the 7.5F scope, and the rates of in situ lithotripsy and postoperative ureteral stent placement were also greater in patients treated with this instrument.

Current trends in ureteroscopy

The advances of technology are having substantial ramifications in medicine and in urology, in particular. This article discusses these advances and explores current trends in ureteroscopy.

Ureteral access strategies: pro-access sheath

Routine use of the ureteral access sheath during flexible ureteroscopic procedures provides consistent, reliable, and unencumbered access to the upper tracts. The ureteral access sheath can be reliably and easily deployed if used properly and requires no special training. As such, it can be easily adopted into current urologic practice. Not only does the access sheath facilitate rapid, repeated, and atraumatic access to the upper tracts, but it also avoids back-loading over a superstiff guidewire, which may incur costly damage to the ureteroscope. The access sheath reduces overall costs and decreases operative times. Furthermore, application of a ureteral access sheath reduces the frustration associated with complex and some routine ureteroscopic procedures by optimizing irrigant flow to improve the surgeon's endoscopic vision while minimizing the intrarenal pressures that the kidney must tolerate. There is no evidence that the access sheath results in clinically significant ureteral ischemia, and extensive clinical use of the access sheath for long procedures has not resulted in increased stricture formation. Finally, the ureteral access sheath is useful for other procedures, such as PCNL, by improving visualization and minimizing the requirement for multiple percutaneous access sites. Winston Churchill said it best: "Give us the tools and we will finish the job." Industry has provided urologists with the tools in the form of advanced flexible ureteroscopes, the holmium laser, nitinol baskets, and the ureteral access sheath. Now it is up to urologists to finish the job.

Ureteroscopes: flexible, rigid, and semirigid

Since its introduction, the ureteroscope has undergone significant improvements. Using the currently available rigid, semirigid, and flexible ureteroscopes and working instruments, urologists can diagnose and treat lesions throughout the upper urinary tract. Over the past 25 years, the ureteroscope in combination with shock wave lithotripsy has transformed the diagnosis and treatment of more than 90% of upper urinary tract pathology from an open to an endourologic procedure. With endoscope manufacturers continually incorporating new technology into their ureteroscopes, future models will undoubtedly provide better optics, increased durability, and improved capabilities, resulting in greater success when urologists perform endoscopic forays into the upper urinary tract.

Comparison of the mechanical, flow, and optical properties of contemporary flexible ureteroscopes

OBJECTIVES

New designs have improved the ability of flexible ureteroscopes to assess the upper urinary tract. However, limitations of tip deflection may interfere with diagnosis and treatment of lower pole renal pathologic features and smaller working channels may impair irrigant flow. Our purpose was to compare the new flexible ureteroscopes with prior models to determine whether engineering advances have overcome these problems.

METHODS

Two newly released flexible ureteroscopes, the ACMI DUR-8 Elite and the Storz 11278AU, were compared with four other ureteroscopes, the ACMI DUR-8, Storz 11274AAU, Olympus URF-P3, and Wolf 9F. Active tip deflection, irrigation flow rates, and intraluminal pressures with and without various endoscopic tools were assessed. The specifications, purchase prices, and repair costs were obtained from the individual manufacturers. Also, the field of view and screen image size of each scope were compared.

RESULTS

The ACMI DUR-8 Elite and Storz 11278AU had improved tip deflection of 79 degrees and 144 degrees, respectively, from previous ureteroscopes. Although the tip deflections of all ureteroscopes were compromised by the insertion of endoscopic tools, new ureteroscopes were less affected. With a 3F basket within the working channel, the ACMI DUR-8 Elite and the Storz 11278AU had a loss of downward deflection of only 0.7% and 2.8% compared with a loss of 9.6% and 5.0% for their older models, respectively. However, the flow rate of these new instruments was decreased.

CONCLUSIONS

The new flexible ureteroscopes have significantly better active tip deflection than previous models, both with and without endoscopic instrumentation inserted. However, improved flexibility comes at the expense of a decreased flow rate.

Ureteroscopy: effect of technology and technique on clinical practice

PURPOSE

Technical advances in ureteroscopy allow for more aggressive management of upper tract pathology. We evaluate to what extent clinical practice and treatment efficacy have been impacted by improvements in technology and technique.

MATERIALS AND METHODS

In 1998, 176 consecutive patients underwent 182 ureteroscopic procedures at our institution. Retrospective chart review was performed. Factors such as clinical indication, pathology location, type of ureteroscope, procedure duration, procedure success, complication rate and length of stay were evaluated. Data from the 1998 cohort were compared to those obtained from a cohort of patients from 1992. Statistical analysis was performed using chi-square test.

RESULTS

Overall stone extraction rate was 94.4% (1992) vs 88.5% (1998) (p = 0.05). Proximal stones were treated in 13.5% (1998) vs 28.3% (1998) of cases. Distal stone extraction rate was 97.2% (1992) vs 95.1% (1998) (p = 0.43) and proximal stone extraction rate was 76.5% (1992) vs 71.9% (1998) (p = 0.73). Diagnostic inspection success rate was 98.3% (1992) vs 98.3% (1998). Use of flexible ureteroscopy was 11.5% (1992) vs 29.4% (1998). Complication rate was 12% (1992) vs 10.2% (1998) (p = 0.76). Of the cases 76.1% were outpatient in 1998 vs only 50% in 1992.

CONCLUSIONS

Recent advances in ureteroscopic technology permit more aggressive instrumentation of the upper tract as reflected in higher use of flexible ureteroscopy and more frequent attempts to manage proximal ureteral calculi. These advances have not translated into better efficacy of calculus treatment. Furthermore, our data reflect a nationwide trend toward outpatient treatment.

Assessment of stricture formation with the ureteral access sheath

OBJECTIVES

To analyze the long-term incidence of ureteral stricture formation in a series of patients in whom a new-generation ureteral access sheath was used. A new generation of ureteral access sheaths has been developed to facilitate ureteroscopic procedures. However, some have questioned their safety and whether the device might cause significant ureteral trauma.

METHODS

Between September 1999 and July 2001, 150 consecutive ureteroscopic procedures with adjunctive use of an access sheath were performed. A retrospective chart review to April 2002 was done. Of the 150 patients, 130 underwent ureteroscopy for ureteral stones. Patients who underwent endoureterotomy or treatment of transitional cell carcinoma were excluded from this analysis. Sixty-two patients had follow-up greater than 3 months and were included in the analysis. Overall, 71 ureteroscopic procedures were performed, with 9 patients undergoing multiple procedures. Ninety-two percent of the patients had pathologic findings above the iliac vessels. The average patient age was 45.3 years (range 17 to 76), and 70% and 30% of the patients were male and female, respectively. The mean clinical follow-up was 332 days (range 95 to 821), and follow-up imaging was performed within 3 months after ureteroscopy in all patients.

RESULTS

The 10/12F access sheath was used in 8 ureteroscopic procedures (11.2%), the 12/14F access sheath in 56 (78.9%), and the 14/16F access sheath in 7 (9.8%). One stricture was identified on follow-up imaging of 71 procedures performed, for an incidence of 1.4%. The patient developed the stricture at the ureteropelvic junction after multiple ureteroscopic procedures to manage recurrent struvite calculi. The access sheath did not appear to be a contributing factor.

CONCLUSIONS

The results of our series indicate that the ureteral access sheath is safe and beneficial for routine use to facilitate flexible ureteroscopy. However, awareness of the potential ischemic effects with the use of unnecessarily large sheaths for long periods in patients at risk of ischemic injury should be considered. We advocate the routine use of the device for most flexible ureteroscopic procedures proximal to the iliac vessels.

Techniques to maximize flexible ureteroscope longevity

OBJECTIVES

To assess methods to improve the longevity and durability of flexible ureteroscopes by using the ureteral access sheath, 200-microm holmium laser fiber, and nitinol baskets or graspers during routine ureteroscopic procedures. Despite adequate advances in fiberoptics and endoscope design, the decreased size of currently available flexible ureteroscopes makes damage inevitable after repeated use. However, new auxiliary tools may be able to enhance ureteroscope durability.

METHODS

The indications for performing flexible ureteroscopy were proximal ureteral stones (n = 32), renal calculi (n = 59), treatment of upper tract transitional cell carcinoma (n = 3), evaluation of hematuria or filling defect (n = 7), and treatment of ureteral strictures or ureteropelvic junction obstruction (n = 8). Using four new 7.5F flexible ureteroscopes, we prospectively evaluated the number of passes of each ureteroscope until more than 20 optical fibers were broken, more than a 25 degrees loss of deflection in either direction had occurred, or the instrument sustained injury requiring repair by the manufacturer.

RESULTS

One hundred nine flexible ureteroscopic procedures (average 27.5 procedures per instrument; range 19 to 34) were performed with the four new flexible ureteroscopes before being sent for repair. Adjuncts to reduce scope damage during these procedures were the use of the ureteral access sheath (n = 109), nitinol devices allowing lower pole stone retrieval (n = 27), and the 200-microm holmium laser fiber for stone fragmentation, tumor ablation, and incision of ureteropelvic junction/ureteral stenoses (n = 91). The average number of passes until more than 20 optical fibers were broken was 15.3 (range 12 to 20), until more than a 25 degrees loss of deflection occurred was 50.3 (range 42 to 66), or until the scope required repair was 66.7 (range 46 to 82).

CONCLUSIONS

Flexible ureteroscopy will be used increasingly to manage upper urinary tract pathologic findings. Historically, the number of procedures performed before a flexible ureteroscope requires repair averaged 6 to 15. By incorporating the new ureteroscopic accessories, such as nitinol devices, a ureteral access sheath, and the 200-microm holmium laser fiber into common practice, one can reduce the strain on these fragile 7.5F endoscopes, thereby maximizing their longevity.

Flexible ureteroscopes: a user's guide

OBJECTIVE

To compare, quantitatively and qualitatively, four small-diameter flexible ureteroscopes.

MATERIALS AND METHODS

Four flexible ureteroscopes from different manufacturers, i.e. the DUR-8 (ACMI, Southborough, MA, USA), Olympus UPF-3 (Keymed, Southend-on-Sea, UK), Storz 11274AA (Karl Storz GmbH, Tuttlingen, Germany) and the Wolf 9 F (Henke Sass Wolf GmbH, Tuttlingen, Germany), were assessed quantitatively by measuring the active tip deflection and irrigation flow rate with laser fibres (200 micro m, 365 micro m), an electrohydraulic lithotripter (1.9 F) and grasping forceps (3 F) in position. They were then assessed subjectively by two endourologists who scored them, using a visual analogue scale (maximum 10), for insertion, deflection mechanism, manoeuvrability, rigidity, image quality and overall satisfaction.

RESULTS

All the endoscopes are < 9 F at the tip, although the length of the smallest diameter (bevelled tip vs section of shaft) was variable. Tip deflection was 87-100% of the manufacturers' specifications and decreased by similar percentages with instruments in the working channel. The irrigation flow rate was comparable for instruments with a 3.6 F working channel (72-88 mL/min with an empty working channel), although much greater for the Wolf, which has a 4 F channel (116 mL/min). Direction and image size were nearly identical, as was the field of view, apart from the Wolf (60 degrees vs 90 degrees ). There was agreement in the user assessment for three instruments, with overall satisfaction scores being Storz (4), ACMI (7.5) and Olympus (8.6), but disagreement in scores for Wolf (1.9 vs 5.3).

CONCLUSIONS

Whilst there were considerable similarities in the objective assessment among the instruments, the user assessment showed qualitative variability. Thus it is important to try the different instruments before selecting one. Additional variables to consider include durability, cost and service/warranty, which vary considerably among instruments.

Retrograde ureteropyeloscopic holmium laser lithotripsy for large renal calculi

OBJECTIVE

To assess the efficacy and safety of the retrograde ureteropyeloscopic holmium laser for treating renal stones that are too large to treat with extracorporeal shock wave lithotripsy (ESWL).

PATIENTS AND METHODS

Thirty patients (22 men and eight women, mean age 43 years, range 18-62) with a renal stone burden of > 2 cm were selected for laser treatment. The stones were in the renal pelvis in 16 patients, lower calyx in five, middle calyx in two, upper calyx in one and multiple pelvic and calyceal in six. Lithotripsy was undertaken using a holmium laser through 550 microm and 200 microm laser fibres passed through a semi-rigid fibre-optic long ureteroscope or the actively deflectable flexible ureteropyeloscope, respectively. Success was defined as total fragmentation of the stone to < 2 mm in diameter and/or clear imaging on renal ultrasonography and plain films within the 3-month follow-up. Patients in whom the treatment failed received either alternative therapy or complementary ESWL.

RESULTS

Endoscopic access and complete stone fragmentation was achieved in 23 of the 30 patients (77%). The treatment failed in seven patients because of poor visualization, the initial presence of stones in, or migration of their large fragments to, an inaccessible calyx. There were no major intraoperative complications. Minor complications after treatment included haematuria that persisted for 2 days in one patient and high-grade fever in two patients; all were treated conservatively.

CONCLUSION

Large renal calculi that are not amenable to ESWL monotherapy can be safely and effectively treated with a retrograde endoscopic technique that seems to compete well with the more invasive percutaneous or open surgical manoeuvres.

Does the cleaning technique influence the durability of the <9F flexible ureteroscope?

BACKGROUND AND PURPOSE

The fragility of the <9F flexible ureteroscope limits its availability to general urology practice. The purpose of this study was to determine whether the technique used to clean the flexible ureteroscope or the number of persons handling the instrument during the cleaning process influenced endoscope breakage or deterioration during regular endourologic use.

PATIENTS AND METHODS

A new Olympus URF/P3 flexible 7.5F ureteroscope was used for each of two 30-day study periods during which a single surgeon used the endoscope for a variety of upper urinary tract procedures. During the first 30-day period (Group 1), the endoscope was leak-proof-pressure tested and cleaned by the endourology support team using the Steris 20 (peroxyacetic acid 35%) technique. During the second 30-day period (Group 2), the endoscope was leak-proof tested and cleaned only by the surgeon using the Cidex (glutaraldehyde 2.4%) technique. A record was kept for each ureteroscopic case to document the patient position, access technique, time the endoscope was in the urinary tract, instruments passed through the ureteroscope, and the maximum irrigant pressure used. In addition, a record was made of the number of broken fibers, the degree of flexion and deflexion of the endoscope, and the problems encountered with the endoscope during the case.

RESULTS

The two study groups were similar in terms of the total number of cases performed, the mean time the endoscope was in the urinary tract per case, the access approach used, and the use of the ureteral access sheath and ancillary equipment. In Group 2, the endoscope was used for a longer total time (618 minutes v 457 minutes), and access to a lower pole calix was more than twice as common as in Group 1. This may explain why more broken fibers were noted in the instrument used in Group 2 over the study period (eight v four broken fibers) than in Group 1. The only breakage occurred as a result of the surgeon accidentally activating the laser probe inside the working channel of the endoscope in Group 2.

CONCLUSION

The technique and number of personnel involved in the maintenance and cleaning of the flexible ureteroscope does not have a significant effect on the durability and function of these instruments. It is the arduous demands of the endourologic procedure that influence the durability of these fragile endoscopes.

Nitinol stone retrieval-assisted ureteroscopic management of lower pole renal calculi

OBJECTIVES

Current ureteroscopic intracorporeal lithotripsy devices and stone retrieval technology allow for the treatment of calculi located throughout the intrarenal collecting system. Difficulty accessing lower pole calculi, especially when the holmium laser fiber is used, is often encountered. We retrospectively reviewed our experience with cases in which lower pole renal calculi were ureteroscopically managed by holmium laser fragmentation, either in situ or by first displacing the stone into a less dependent position with the aid of a nitinol stone retrieval device.

METHODS

Thirty-four patients (36 renal units) underwent ureteroscopic treatment of lower pole renal calculi between April 1998 and November 1999. Lower pole stones less than 20 mm were primarily treated by ureteroscopic means in patients who were obese, in patients who had a bleeding diathesis, in patients with stones resistant to shock wave lithotripsy, and in patients with complicated intrarenal anatomy, or as a salvage procedure after failed shock wave lithotripsy. Lower pole calculi were fragmented with a 200-micrometer holmium laser fiber by way of a 7.5F flexible ureteroscope. For those patients in whom the laser fiber reduced the ureteroscopic deflection, precluding re-entry into the lower pole calix, a 3.2F nitinol basket or a 2.6F nitinol grasper was used to displace the lower pole calculus into a more favorable position, allowing easier fragmentation.

RESULTS

In 26 renal units, routine in situ holmium laser fragmentation was successfully performed. In the remaining 10 renal units, a nitinol device was passed into the lower pole, through the ureteroscope, for stone displacement. Only a minimal loss of deflection was seen. Irrigation was significantly reduced by the 3.2F nitinol basket, but improved with the use of the 2.6F nitinol grasper. This factor did not impede stone retrieval in any of the patients. At 3 months, 85% of patients were stone free by intravenous urography or computed tomography.

CONCLUSIONS

Ureteroscopic management of lower pole calculi is a reasonable alternative to shock wave lithotripsy or percutaneous nephrolithotomy in patients with low-volume stone disease. If the stone cannot be fragmented in situ, nitinol basket or grasper retrieval, through a fully deflected ureteroscope, allows one to reposition the stone into a less dependent position, thus facilitating stone fragmentation.

Flexible ureterorenoscopy for the treatment of refractory upper urinary tract stones

OBJECTIVE

To report our experience of using flexible ureterorenoscopy for upper urinary tract stones.

PATIENTS AND METHODS

Thirty-seven patients (13 females, 24 males, mean age 48 years, range 10-76) with upper urinary tract stones not responding to other treatments had their residual symptomatic stones treated through a 9.3 F flexible ureterorenoscope. Electrohydraulic lithotripsy (EHL) was used to fragment the stones and a basket or a grasper used to retrieve the fragments.

RESULTS

Twenty-three patients were completely freed of stone and a further five had asymptomatic residual fragments of < 5 mm. Of 15 patients with ureteric stones, 14 were rendered stone-free at the end of the procedure and 14 of the 22 patients with kidney stones were treated successfully; 80% of the lower calyceal stones were treated successfully and a firm decision was possible on the further management of the remaining stones. There were no major complications.

CONCLUSION

Flexible ureterorenoscopy should be considered in patients with symptomatic upper ureteric or renal stones refractory to other treatments, but the instrumentation is expensive and delicate, and its use should be reserved for such cases.

Routine radiologic surveillance for obstruction is not required in asymptomatic patients after ureteroscopy

OBJECTIVE

A retrospective medical record review was performed with the goal of determining the need for radiologic evaluation after ureteroscopy.

PATIENTS AND METHODS

Of 183 patients undergoing ureteroscopic procedures at our institution between 1989 and 1993, 131 underwent postoperative radiologic studies capable of diagnosing ureteral obstruction. Of these patients, 110 (84%) were asymptomatic after the procedure, and radiologic procedures capable of displaying obstruction were performed at a median of 60 days (mean 73 days; standard deviation 189 days) after ureteroscopy.

RESULTS

None of these asymptomatic patients displayed obstruction at the time of the routine follow-up radiologic procedure. Of those 21 patients (16%) who experienced flank pain subsequent to ureteroscopy, 13 were found to have ureteral obstruction secondary to ureteral calculus. One patient (1/131 or 0.8%) was found to have a ureteral stricture, which occurred after a full-thickness ureteral injury. All cases of postoperative obstruction were heralded by a concomitant display of flank pain.

CONCLUSION

Routine postoperative radiologic studies are not necessary in surveillance for obstruction in the asymptomatic postureteroscopy patient, as obstruction should become evident by virtue of flank pain. The exception to this practice may be in patients experiencing a ureteral perforation intraoperatively, who may be at greater risk of stricture.

Ureteropyeloscopy in the diagnosis of patients with upper tract hematuria: an initial clinical study

BACKGROUND

To study the usefulness and safety of ureteropyeloscopy in the diagnosis of upper tract hematuria of unknown etiology by standard diagnostic methods.

METHODS

Fifteen patients with upper tract hematuria of unknown etiology were the subjects of the present study. Prior to ureteropyeloscopy, they underwent standard diagnostic methods, including cystourethroscopy, excretory urography and computed tomography scan. The upper tract (ureter, renal pelvis and calyces) was inspected systematically with a flexible ureteropyeloscope under epidural anesthesia. A biopsy specimen was obtained when neoplasm of a suspicious lesion was seen. Bleeding and hemangiomatous lesions were fulgurated at the time of ureteropyeloscopy.

RESULTS

Unilateral gross hematuria was seen in 12 patients. Imaging studies revealed a filling defect in four patients, ureteral stenosis in one patient and nutcracker phenomenon in one patient. Urine cytology was positive in three patients and suspicious in four patients. Results of ureteropyeloscopy were papillary tumor in three patients, whitish encrustation in one patient, redness of the renal pelvis in one patient, bleeding from the renal calyx in two patients, hemangiomatous lesion in one patient, ureteral stenosis in two patients and no abnormalities in five patients. Biopsies were performed in five patients. The pathology results were transitional cell carcinoma in four patients and no abnormality in one patient. Although a ureteral stent catheter was placed in one patient, no serious complications were encountered during or after the procedures.

CONCLUSIONS

Ureteropyeloscopy was useful and relatively safe. This endoscopic examination can differentiate insignificant lesions from significant lesions by visual inspection of the lesions, in addition, pathological diagnosis by biopsy specimen can also be performed if deemed necessary. Ureteropyeloscopy is recommended in the diagnosis of upper tract hematuria of unknown etiology.