Flexible upper tract endoscopy

Laser lithotripsy using dusting technique (low energy, high frequency) for symptomatic upper urinary tract stones

Background

A prospective study to assess the feasibility of stone dusting technique (low energy and high frequency) during laser lithotripsy in symptomatic upper urinary tract |(UUT) stones.

Methods

Sixty patients with symptomatic single or multiple UUT stones less than 3 cm in diameter were included. Patients with coagulation disorders and active UTIs were excluded. All patients were clinically evaluated and underwent non-contrast spiral CT (NCSCT) to detect stone site, size, number, Hounsfield unit. A rigid or flexible ureteroscope was used with stone dusting using the Ho: YAG laser at low-energy and high-frequency (0.5 J & 20 Hz) set. Operative and fluoroscopy time, total energy delivered, type of stent, hospitalization time, complications and its grade, and stone-free rate using NCSCT after 4 weeks were recorded.

Results

The mean stone size ± SD (range) was 1.55 ± 0.55 (0.5–3) cm; out of sixty patients (50 with single stone and 10 with multiple stones), fifty-five patients were stone-free at 4 weeks. Complications had occurred in 11 patients (eight with grade I, one with grade II, and two with grade IIIa) according to Clavien–Dindo grading of surgical complications. Stone size was the only parameter which correlated significantly with stone-free rate. No significant correlation was found between incidence of complications and other parameters (stone size, site, BMI, age and operative time).

Conclusions

Stone dusting technique is feasible, safe and effective in management of UUT stones.

Advantages of retrograde flexible ureteroscopy in determining the etiology of painless hematuria originating from the upper urinary tract

The present study investigated the use of retrograde flexible ureteroscopy (RFU) in the discrimination of the etiology of hematuria that originates from the upper urinary tract (UUT). The present study collected retrospective data for patients who presented with hematuria and cystoscopy-detected bleeding from the UUT between June 2006 and August 2018 in Ningbo First Hospital. All patients accepted RFU to determine the etiology of hematuria. Data regarding imaging examinations, surgery, pathology and complications were also collected and analyzed. In total, 65 patients (males, 38; females, 27) with a mean age of 63 years underwent RFU to determine the etiology of hematuria originating from the UUT. Using RFU, UUT tumors were found in 29 cases. Stones, polyps and atypical hyperplasia were found in two cases, and a definite diagnosis was not found in three cases. There were 17 cases without obvious abnormalities and nine cases were unable to undergo RFU due to ureteral stenosis. In patients who could not be diagnosed by imaging examination, 34.4% (11/32) were diagnosed with urothelial carcinoma by RFU, and these results were also confirmed by postoperative pathology. In the present study, no patient had severe complications after RFU. The present results suggested RFU may be used as a sensitive method to diagnose UUT tumors (78.4%; 29/37) and has strong specificity. RFU could be performed as a routine examination for patients with hematuria from the UUT.

Extracorporeal shockwave lithotripsy vs. percutaneous nephrolithotomy vs. flexible ureterorenoscopy for lower-pole stones

Objectives

To review previous reports and discuss current trends in extracorporeal shockwave lithotripsy (ESWL), percutaneous nephrolithotomy (PCNL) and ureterorenoscopy (URS). ESWL was recommended as the first-line treatment for small and intermediate-sized stones in the lower pole, while it is the standard treatment for large stones. However, the stone clearance rate after ESWL seems to be lower than that of stones in other locations. This seems to result from a lower rate of fragment passage, due to anatomical factors.

Methods

Reports on urinary stone disease were reviewed, assessing only publications in peer-reviewed, Medline-listed journals in the English language (publication years 1990–2011).

Results

Recent experience with flexible URS (fURS) for intrarenal stones showed that excellent stone-free rates can be achieved. With increasing experience and technically improved equipment, fURS has become an alternative to ESWL for small and intermediate-sized renal stones. Furthermore, several authors reported successful retrograde treatment for large renal stones, proposing fURS as an alternative to PCNL. However, the major drawbacks are long operating times and commonly, staged procedures, which is why PCNL remains the method of choice for such stones.

Conclusions

Considering the currents trends and evidence, the 2012 update of the European Association of Urology Guidelines on Urolithiasis has upgraded the endourological treatment of kidney stones. Individual factors such as body habitus, renal anatomy, costs and patient preference must be considered.

Outcomes and Safety of Retrograde Intra-Renal Surgery for Renal Stones Less Than 2 cm in Size

Background

Retrograde intra-renal surgery (RIRS) has been used to remove stones of less than 2 cm in the kidney. However, its role is not well defined.

Objectives

The objective of this study was to evaluate the outcomes and safety of RIRS, used either as a primary or secondary procedure, and to analyze factors predicting the stonefree rate (SFR).

Patients and Methods

A retrospective analysis was performed on data from patients who underwent RIRS over a 10-year period (2002–2012). Stone size was measured as the surface area and was calculated according to the EAU guidelines. In cases of multiple stones, the total stone burden was calculated as the sum of each stone size. Stone burden was then classified as ≤ 80 mm² or > 80 mm². RIRS was classified as primary procedure or secondary procedure (after failed extracorporeal shockwave lithotripsy or percutaneous nephrolithotripsy).Stone clearance was defined as a complete absence of stones or stones < 4 mm, which were deemed insignificant on ultrasonography and plain radiography.

Results

The overall SFR for renal stones treated with RIRS in our center was 55.4%, and the complication rate was 1.5%, which consisted of one case of sepsis. The only factor affecting SFR in this study was the indication for RIRS. When performed as a primary operation, RIRS showed a significantly better SFR (64.3%). The SFR for lower pole stones was only 44.4%. There were no statistically significant effects of stone burden, radio-opacity, or combination with ureteral stones on SFR.

Conclusions

RIRS should be used as the primary treatment for renal stones whenever possible.

The PolyScope: a modular design, semidisposable flexible ureterorenoscope system

PURPOSE

To characterize the mechanical and optical properties of the PolyScope endoscope system and to examine the clinical outcome in patients who were undergoing ureteronephroscopy.

MATERIALS AND METHODS

Mechanical assessment involved measurement of the deflection angle and irrigation flow rate. Optical resolution and distortion, field and angle of view, and light transmission and output formed the optical assessment. Clinical assessment was made in a series of consecutive ureteronephroscopy procedures. The optical cord was disconnected after each procedure, and the image fiber was assessed for damage.

RESULTS

The mean value for the angle of maximum active tip deflection with an empty working channel was 265 degrees (261-275 degrees). Deflection was impaired most with insertion of the 3.0 F basket (10% decrease) and least with an indwelling 220 microm laser fiber (2% decrease). Irrigation flow rate was 57 mL/min with an empty working channel. Flow was reduced by 50% and 68%, with the insertion of a 200 microm or 365 microm laser probe, respectively, and by 92.5% with a 3.2F basket. No damage to the image fiber occurred. The PolyScope optics system could identify a target of about 0.125 mm at a distance of 2 to 4 mm, based on 3 line-pairs/mm needed for clear identification. Lithotripsy of renal calculi was performed for 40 stone burdens in 32 patients; the resulting stone-free rate was 87.5%.

CONCLUSION

The novel semidisposable ureteroscope system PolyScope was simple to use, effective, and reliable in this preliminary clinical evaluation. It overcomes the inherent fragility of comparable devices, which renders the need for maintenance unnecessary.

In vitro comparison of a disposable flexible ureteroscope and conventional flexible ureteroscopes

PURPOSE

We compared and evaluated the objective characteristics (deflection characteristics, field of view and flow rate) of a disposable flexible ureteroscope and 6 established, commercially available flexible ureteroscopes.

MATERIAL AND METHODS

Six commonly used ureteroscopes, including Olympus URF-P3, Storz(R) 11278AU and 11274AAU, ACMI DUR-8 Elite and DUR-8, and Wolf 7331.001 (Richard Wolf Medical Instruments, Vernon Hills, Illinois), were compared with the recently introduced SemiFlex Scope disposable flexible ureteroscope. Specifications and purchase costs were acquired from each manufacturer. The disposable ureteroscope consisted of a reusable eyepiece and a semiflexible shaft with a 3.3Fr working channel. Active tip deflection was measured with and without the 3Fr basket, the 365 mum laser fiber and the 3Fr forceps. The flow rate and field of view of each scope were evaluated.

RESULTS

Active tip deflection (down/up) was highest in the disposable ureteroscope at 300/265 degrees. Although deflection was decreased by inserting the different endoscopic tools in all ureteroscopes, the disposable ureteroscope had the highest loss in flexion characteristics (35.7% down and 39.3% up). The flow rate, measured at 25 ml per minute in the disposable ureteroscope, was significantly lower than that of other ureteroscopes. The disposable ureteroscope had a 72-degree field of view, comparable to the optical characteristics of the other scopes. Compared to the other 6 flexible ureteroscopes the purchase price of the disposable scope was significantly lower and no further maintenance/repair expenses were required.

CONCLUSIONS

The disposable flexible ureteroscope has acceptable active tip deflection, field of view and flow rate compared to those of other flexible ureteroscopes on the market. Further evaluation of surgical outcomes will help delineate the definitive usefulness of the disposable flexible ureteroscope.

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.

Extracorporeal shock wave lithotripsy in the treatment of renal pelvicalyceal stones in morbidly obese patients

INTRODUCTION

Management of urolithiasis in morbidly obese patients is usually associated with higher morbidity and mortality compared to non-obese patients. In morbidly obese patients, since the kidney and stone are at a considerable distance from the skin (compared to non-obese patients) difficulty may be found in positioning the patient so that the stone is situated at the focal point of the lithotripter.

OBJECTIVE

To evaluate the outcomes and cost-efficiency of extracorporeal shock wave lithotripsy (ESWL) in the treatment of renal pelvicalyceal stones sized between 6 and 20 mm in morbidly obese patients.

MATERIALS AND METHODS

Using various aids, such as mobile overtable module, extended shock pathway and abdominal compression 37 patients with body mass index more than 40 kg/m2 were treated using the Siemens Lithostar-plus third generation lithotripter. The size of renal pelvicalyceal stones was between 6 and 20 mm. Treatment costs for shock wave lithotripsy were calculated.

RESULTS

The overall stone free rate at 3 months of 73% was achieved. The mean number of treatments per patient was 2.1. The post-lithotripsy secondary procedures rate was 5.4%. No complications, such as subcapsular haematoma or acute pyelonephritis were recorded. The most effective (87% success rate) and cost-efficient treatment was in the patients with pelvic stones. The treatment of the patients with low caliceal stones was effective in 60% only. The cost of the treatment of the patients with low calyceal stones was in 1.8 times higher than in the patients with pelvic stones.

CONCLUSION

We conclude that ESWL with the Siemens Lithostar-plus is the most effective and cost-efficient in morbidly obese patients with pelvic stones sized between 6 and 20 mm. 87% success rate was achieved. The increased distance from the skin surface to the stone in those patients does not decrease the success rate provided the stone is positioned in the focal point or within 3 cm of it on the extended shock pathway. ESWL should not be considered as the first line of treatment in the morbidly obese patients with low caliceal stones where the stone was positioned more than 1 cm from the focal point on the extended shock pathway.