PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Ureteroscopes”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2002

Bare naked baskets: ureteroscope deflection and flow characteristics with intact and disassembled ureteroscopic nitinol stone baskets.

PURPOSE: Lower pole renal access during flexible ureterorenoscopy is often limited by the active deflection capabilities of the ureteroscope. Deterioration in the deflection and flow capabilities of ureteroscopes occurs with the passage of instrumentation through the working channel. We performed in vitro evaluation of a novel technique using unsheathed nitinol baskets to minimize the deterioration in deflection and maximize the irrigant flow associated with instrument passage through the working channel during flexible ureterorenoscopy. MATERIALS AND METHODS: Alterations in the irrigant flow and active deflection of 4 ureteroscopes from different manufacturers were evaluated. Each ureteroscope was evaluated with an empty working channel, and then with sheathed and unsheathed 2.2, 3 and 3.2Fr (Cook Urological, Inc., Indianapolis, Indiana), 2.4 and 3Fr (Microvasive Urology, Natick, Massachusetts) nitinol baskets in the working channel. RESULTS: With all baskets tested and in all ureteroscopes the deterioration in active deflection and irrigant flow was improved with the unsheathed baskets. The disassembled basket within the working channel allowed an additional 15 to 20 degrees of active deflection. In addition, the disassembled basket allowed for a 2 to 30-fold increase in irrigant flow compared with an intact basket. CONCLUSIONS: The combination of improved deflection and irrigant flow with this technique may improve ureteroscopic access to lower pole renal calculi.

Alloys↗
PubMed2005

Evaluation of the mechanisms of damage to flexible ureteroscopes and suggestions for ureteroscope preservation.

AIM: To investigate the causes and costs of flexible ureteroscope damage, and to develop recommendations to limit damage. METHODS: The authors analysed repair figures and possible causes of damage to 35 instruments sent for repair to a leading UK supplier over a 1-year period, and calculated cost figures for maintenance of the instruments as opposed to repair and replacement costs. RESULTS: All damages were handling-induced and therefore did not fall under the manufacturer's warranty: 28 % were damaged by misfiring of the laser inside the instrument; 72 %, mainly crushing and stripping of the ureteroscope shaft tube, were likely to have occurred during out-of-surgery handling, washing and disinfection. Seventeen (4 %) instruments were not repaired and consequently taken out of service due to the extensive costs involved. Eighteen (51 %) ureteroscopes were repaired at an average cost of 10 833 USD. CONCLUSION: Damages to flexible ureteroscopes bear considerable costs. Most damages occur during handling between surgical procedures. Thorough adherence to handling procedures, and courses for theater staff and surgeons on handling flexible instruments may help to reduce these damages and prove a cost-saving investment. The authors provide a list of recommended procedural measures that may help to prevent such damages.

Durable Medical Equipment↗
PubMed2006

Durability of working channel in flexible ureteroscopes when inserting ureteroscopic devices.

PURPOSE: We studied the physical damage to the working channel of flexible ureteroscopes caused by insertion of various accessories. A procedure was developed to avoid channel damage. MATERIALS AND METHODS: An experimental model representing a flexible ureteroscope was prepared, and damage to its working channel was evaluated by inserting instruments through it. Deflection angles of the channel were changed from 0 degrees to 120 degrees, and each device was inserted and removed 100 times for each selected angle of the channel. Any induced pinholes were identified by an air-leak test. Also, the inside of the channel was inspected with an extremely fine fiberscope. RESULTS: Insertions of 3F biopsy forceps or a 2.4F Nitinol stone-retrieval device caused only slight damage to the model channel, even when the deflection angle was 120 degrees. However, the tips of 200- or 250-microm holmium laser fibers shaved the inner surface of the channel at 60 degrees of deflection, and at 120 degrees, the laser fiber either penetrated the channel or could not be advanced because of resistance by the channel wall. When the laser fiber was inserted within a protective tube, the channel was never damaged, even when the deflection angle was 120 degrees. CONCLUSIONS: When devices are inserted into the working channel of a flexible ureteroscope, damage to the wall depends on the kind of device and deflection angle. Harm could be avoided by inserting the devices, especially laser probes, within a protective tube.

Equipment Design↗
PubMed2005

Ureteric access with flexible ureteroscopes: effect of the size of the ureteroscope.

OBJECTIVE: To determine the optimum size of a flexible ureteroscope (FU) to minimize the need for ureteric dilatation. MATERIALS AND METHODS: FUs from several different manufacturers and with different shaft diameters were used for ureteroscopy in adults. An initial attempt was made to pass one of the larger diameter FUs; if this was unsuccessful, the smaller 7.5 F FU was used. The results were reviewed retrospectively. RESULTS: Flexible ureteroscopy was used in 115 consecutive patients at two different institutions. The ability to pass the FUs with no formal dilatation was directly related to the FU diameter. The rate of failing to pass with no formal dilatation was 37% for the 9.0 F, 8.5% for the 8.6 F, 5% for the 8.4 F and 0.9% for the 7.4 F ureteroscope. CONCLUSION: Although other factors influence the overall effectiveness of the FU, the ability to pass FUs is directly related to their outer diameter. When only the ease of introduction is considered, the ideal ureteroscope outer diameter is 7.4 F.

Adult↗
PubMed2006

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.

Equipment Failure↗
PubMed2004

Improved functional deflection with a dual-deflection flexible ureteroscope.

PURPOSE: To compare the maximal active deflection capabilities of a newly designed dual-deflection ureteroscope with those of a standard flexible ureteroscope. MATERIALS AND METHODS: The dual-deflection ureteroscope is similar in design to single-deflection ureteroscopes with the addition of a second, more proximal unidirectional deflection point, which is controlled with the index finger on the contralateral side of the instrument. We evaluated the maximal deflection angles achieved with this ureteroscope with no inserted devices as well as with 200-, 365-, and 550-microm laser fibers and a 3F Nitinol wire basket in the working port. We compared these angles with those obtained with the Dur-8 single-deflection ureteroscope. RESULTS: The dual-deflection ureteroscope allowed a superior maximum active deflection angle of 234.3 degrees with an empty working channel compared with only 143 degrees for the standard single-deflection ureteroscope. Instruments in the working channel dampened the active deflection of both ureteroscopes. The average maximum upward angles achievable with the single-deflection ureteroscope with the 200-, 365-, and 550-microm laser fibers and the 3F basket were 115.3 degrees, 92 degrees, 46.6 degrees, and 123.3 degrees, respectively. The average deflection angles with the dual-deflection endoscope deflected at the distal point were similar to those obtained with the single-deflection ureteroscope. In contrast, the average maximum deflection angles obtained with the dual-deflection endoscope deflected at both points with a 200-, 365-, and 550-microm laser fiber and a 3F basket in the working channel were 211 degrees, 183.3 degrees, 109 degrees, and 224 degrees, respectively. The degree of dampening by larger instruments was greater in the single-deflection than the dual-deflection ureteroscope. CONCLUSIONS: The double-deflection ureteroscope can achieve superior active deflection compared with a standard ureteroscope. The second active angle allows the use of larger instruments in the working port with a smaller impact on overall deflection. The double-deflection ureteroscope should be beneficial in the management of difficult-to-treat lower-pole renal calculi and may allow some patients who would have required percutaneous nephrolithotomy to undergo ureteroscopic management of their stone disease.

Humans↗
PubMed2005

Location and etiology of flexible and semirigid ureteroscope damage.

OBJECTIVES: To perform an analysis of currently available manufacturer data regarding the character of ureteroscope damage. The high costs associated with the repair of flexible and semirigid ureteroscopes are well documented. Increased knowledge of the etiology of ureteroscope damage should aid urologists in prolonging the lives of these delicate instruments. METHODS: We requested data from the four major ureteroscope manufacturers (ACMI, Olympus America, Karl Storz, and Richard Wolf) on the types, speculated causes, costs, and frequency of ureteroscope damage. The results were tabulated in a blinded fashion and analyzed for trends. We then formulated guidelines that could be applied by practicing urologists. RESULTS: For both flexible and semirigid ureteroscopes, the frequency of repair increased with decreasing ureteroscope diameter and increasing instrument length. The cost of the repair was generally greater for flexible ureteroscopes (mean 4597 dollars) than for semirigid ureteroscopes (mean 2437 dollars). The major causes of flexible ureteroscope damage were working channel damage from laser burn or instrument passage and extreme scope deflection with an indwelling instrument. The primary reasons for semirigid ureteroscope repair included overtorquing and improper handling in the operating room and during sterile processing. CONCLUSIONS: Urologists can minimize the repair costs of flexible and semirigid ureteroscopes by taking precautions to eliminate laser fiber-induced damage and by avoiding overdeflection. Improved storage and handling of these instruments is also necessary. Although small-diameter ureteroscopes are favorable because of their increased mobility and ease of passage, physician and staff awareness of their increased fragility is vital in maximizing the longevity of these commonly used instruments.

Equipment Design↗
PubMed2005

Comparison of flexible ureteroscopes: deflection, irrigant flow and optical characteristics.

PURPOSE: We measured and compared the deflection, irrigation flow rates, distortion, resolution and light transmission of new generation flexible ureteroscopes. MATERIALS AND METHODS: Multiple characteristics of 5 flexible ureteroscopes (ACMI DUR-8 Elite, Olympus URF-P3, Storz 11278AU1 [Flex-X], Wolf 7330.072 and Wolf 7325.172) commonly available in the market were measured and compared. Measured data included active deflection, irrigation flow rates and optical characteristics. Each ureteroscope was evaluated with an empty working channel and with various accessories. Optical characteristics, specifically resolution and distortion, were measured using test targets (Edmund Optics, Barrington, New Jersey). Light transmission was also measured from the ureteroscope tip at 50% and 100% intensity. All 5 flexible ureteroscopes were tested in a laboratory setting using a Storz OR 1 system to capture the images. RESULTS: For all 5 ureteroscopes the angle of deflection was most impaired by a 365 microm laser fiber probe and least impaired by a 2.2Fr nitinol basket. Among all 5 ureteroscopes irrigation flow rate was most impaired with a 3.0Fr basket and least impaired with 200 microm laser fiber. The Wolf 7325.172 had the highest observed resolution of 25.39 lines per mm and the Wolf 7330.072 had the lowest distortion at 11.9%. The Karl Storz Flex-X and the ACMI DUR-8 Elite had the highest light output at 374 and 364 mV, respectively. CONCLUSIONS: The various flexible ureteroscopes differ with regard to flow rates as well as degree of deflection with either an empty or an occupied working channel. The Wolf flexible ureteroscope with a slightly larger working channel and a fused quartz bundle provided for superior flow and better optical performance. However, the greatest amount of tip deflection and highest light output were found in the ACMI and Karl Storz flexible ureteroscopes.

Artifacts↗
PubMed2002

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.

Equipment Failure↗
PubMed1997

Diagnostic accuracy of ureteroscopic biopsy in upper tract transitional cell carcinoma.

PURPOSE: Our aim was to determine the accuracy of ureteroscopic biopsies and cytological techniques compared to open surgical specimens of upper tract transitional cell carcinoma. MATERIALS AND METHODS: From 1985 to 1995, 51 cases of upper tract transitional cell carcinoma were diagnosed ureteroscopically and distal ureterectomy or nephroureterectomy was performed. Each patient underwent direct ureteroscopic inspection and biopsy. Fresh samples were delivered to the cytopathology laboratory, where they were examined using cytospin and smear. A cell block was prepared when visible tissue was present. Grades of ureteroscopic biopsies were compared to grades and stages of surgical specimens in 42 cases. RESULTS: Cytological evaluation was positive for malignancy in 48 of the 51 cases (94.1%). Grading of ureteroscopic specimens was possible in 42 cases (82.4%). Transitional cell carcinoma grade on ureteroscopy accurately predicted tumor grade and stage in the surgical specimens. Of 30 low or moderate grade ureteroscopic specimens 27 (90%) proved to be low or moderate grade transitional cell carcinoma in the surgical specimens, while 11 of the 12 high grade ureteroscopic specimens (91.6%) proved to be high grade transitional cell carcinoma (p < 0.0001). Of 30 low or moderate grade ureteroscopic specimens 26 (86.6%) had a low stage (Ta or T1) tumor. In contrast, 8 of 12 high grade ureteroscopic specimens (66.7%) had invasive tumor (stage T2 or T3) in the surgical specimen (p = 0.0006). CONCLUSIONS: Ureteroscopic inspection and biopsy combined with cytological techniques provide accurate information regarding grade and stage of upper tract transitional cell carcinoma.

Adult↗
PubMed2003

Evaluation of overall costs of currently available small flexible ureteroscopes.

OBJECTIVES: To perform a meta-analysis of the currently available data regarding the durability of flexible ureteroscopes to establish cost estimates for the purchase and use of five currently available, smaller than 9F, ureteroscopes. Healthcare costs have become increasingly germane to the determination of disease management strategies. Improved ureteroscope technology has expanded the role of these instruments. However, the initial purchase costs and high maintenance costs have become problematic with these fragile instruments. METHODS: Ureteroscope durability data on the Storz 11274AA, Olympus URF-P3, Wolf 7325.172, ACMI AUR-7, and ACMI DUR-8 were collected from three prior studies. Combining the durability data and cost data regarding the initial purchase price and maintenance costs of these instruments, we calculated the overall costs associated with the use of each of the ureteroscopes for 25, 50, 75, and 100 cases during the first year (warranties included) and with subsequent use. RESULTS: The variability in the costs associated with the use of the currently available smaller than 9F ureteroscopes was significant. The initial instrument purchase price, durability, repair costs, and associated warranties all contributed to large discrepancies in the cost of performing ureteroscopy. In this model, during the first year of ownership, the projected cost of performing 100 ureteroscopic cases varied by a difference of 95% depending on the ureteroscope used. CONCLUSIONS: Physicians and institutions that perform ureteroscopy should strongly consider the purchase price, durability, repair cost, and associated warranties before the purchase of small flexible ureteroscopes.

Costs and Cost Analysis↗
PubMed2000

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.

Adult↗
PubMed2003

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.

Equipment Design↗
PubMed2004

Physical properties of flexible ureteroscopes: implications for clinical practice.

BACKGROUND AND PURPOSE: Physical characteristics may be important in the performance of a flexible ureteroscope. This study evaluated the strength of the shaft and deflection mechanism of several instruments. MATERIALS AND METHODS: Sequential loads were placed along the axis of downward deflection to measure the stiffness of the shaft and strength of deflection. Bending pressure was defined as the force required to deflect the tip of the ureteroscope 15 degrees from baseline. Buckling pressure was defined as the force that resulted in catastrophic bending (>90 degrees) of the shaft of the ureteroscope. Strength of deflection was defined as the force that resulted in loss of 10 degrees of active deflection. RESULTS: Bending pressures were lower for the Olympus URF-P3 (6.4 g) and Wolf 7325.172 (6.0 g) ureteroscopes. Similarly, buckling pressures were lower for these two ureteroscopes (9.0 g and 11.6 g, respectively). The Wolf and Storz flexible ureteroscopes had stronger deflection mechanisms than the Olympus URF-P3 and the ACMI DUR-8. CONCLUSIONS: This study demonstrates significant differences in ureteroscope strength. Higher buckling pressures may facilitate advancement of a ureteroscope over a guidewire but may impede secondary deflection. Lower bending pressures may facilitate passive intrarenal manipulation. Strength of deflection may impact the ability to maintain deflection with an instrument in the working channel.

Equipment Design↗
PubMed2004

Exaggerated primary endoscope deflection: initial clinical experience with prototype flexible ureteroscopes.

OBJECTIVE: To increase the clinical usefulness of the actively deflectable flexible ureteroscope by making sequential changes in design and then using these prototypes clinically; and to develop a clinical series using the optimum prototype and contrast it with an extensive database of patients treated with the traditional flexible ureteroscope. METHODS: A series of prototypic flexible ureteroscopes was developed and used clinically. The active deflection of the prototype ureteroscope was evaluated with and with no accessories in the working channel, and compared with a standard 7.5 F ureteroscope. Clinical data were then accrued and compared with a previously published database. RESULTS: The progression of prototypes led to a final version which incorporated > 300 degrees primary active deflection, shaft miniaturization (8.4 F) and an increase in endoscope shaft stiffness. The prototype flexible ureteroscope had significantly greater active deflection than the standard ureteroscope, especially when working channel accessories were used. In all, 115 endoscopic procedures were carried out, the indications for which included endoscopic lithotripsy for distal calculi (51), treatment of upper tract urothelial carcinoma (27), diagnostic endoscopy (26) and retrograde endopyelotomy (three). No guidewire was required to place the flexible ureteroscope into the upper urinary tract in 27% of patients. Active intramural dilatation for access was only required in 3% of the procedures. All lower pole calyces were accessed with this instrument. CONCLUSIONS: Adding exaggerated deflection is a timely advance in flexible ureteropyeloscopy. This and the other changes in design facilitated complex retrograde endoscopic procedures and increased the therapeutic potential of the instrument.

Equipment Design↗
PubMed1995

[Use of semirigid ureteroscopes for treatment of ureteral calculi].

BACKGROUND: The objective of this study is to evaluate the efficacy of ureteroscopic lithotripsy as the treatment of ureteral stones in the recent era by comparing the result using a semirigid ureteroscope with the result using a conventional ureteroscope. METHODS: Between 1991 and 1994, 136 patients with ureteral calculi underwent transurethral ureteroscopic lithotripsy in our hospital. From July 1991 to March 1993, 14F rigid ureteroscope with the rod lens system was used for 82 patients (group 1), whereas from April 1993 to July 1994 either a 9.5F or 7F semirigid fiberoptic ureteroscope was used for 54 patients (group 2). Insertion of ureteroscopes was performed under continuous irrigation of saline without mechanical dilation of the ureteral orifice in both groups. RESULTS: The rates of complete removal of stone at the first trial were 56.1% in group 1 and 72.2% in group 2 with the overall complete removal rate of 62.5%. The complete removal rates of stones in the upper, middle and lower ureters were 18.2%, 54.8% and 72.4% in group 1 and 14.3%, 72.7% and 88.0% in group 2, respectively. The major reasons for unsuccessful treatments was upward migration of stones during the procedure. As intraoperative complications, ureteral disruption occurred in 1 case in group 1, and ureteral perforation in 5 patients in group 1 (6.1%) and 2 in group 2 (3.8%). Acute bacterial infection with prolonged fever was observed in 3 patients in group 1 and in none in group 2. CONCLUSION: From these results, the new semirigid ureteroscope with fiberoptic imaging bundles made the transurethral lithotripsy a safer and more efficient procedure for the treatment of ureteral calculi especially those in the lower ureters.

Adolescent↗