Endoscopic lithotripsy and the FREDDY laser: initial experience.

BACKGROUND AND PURPOSE: The frequency-doubled double-pulse neodymium:YAG (FREDDY) laser has been developed for endoscopic lithotripsy and combines the characteristics of solid and dye lasers with a thin flexible optical fiber enabling it to be used with flexible ureterorenoscopy. Furthermore, it is less expensive and easier to maintain than other lasers. Our goal was to evaluate its efficacy and role in the ureteroscopic treatment of urinary stones. PATIENTS AND METHODS: We used a FREDDY laser in 26 patients (29 stones). For 4 stone cases, this was the first line of treatment; for the remaining cases, this was the second line of treatment, following SWL in 23 cases and nephrolithotomy in 2 cases. The mean stone size was 9 mm, with a range of 6 to 15 mm. There were 13 renal and 16 ureteral stones. The absence of residual fragments at 3-month postoperative radiography was considered to reflect successful treatment. RESULTS: Twenty-six stones were treated with satisfactory results. Within 3 months, 18 patients were stone free (69%), and 72.4% of the stones (21/29) had been treated completely. Fragments of 8 stones still remained in 8 patients. Of these stones, 5 were >10 mm and persisted at 3 months. Fragmentation was ineffective for 2 cystine stones and poor for 1 calcium oxalate monohydrate stone. Hospitalization, on average, was 1.5 days with a range of 1 to 3 days. A ureteral perforation was observed in the case of an impacted ureteral stone. CONCLUSIONS: Because of the wavelengths used, endoscopic FREDDY laser lithotripsy is an effective and harmless method. This laser can be used as a therapeutic tool because of its moderate cost and ability to be used with flexible ureterorenoscopy. However, it is important to be aware of the FREDDY laser's limited fragmentation capabilities for cystine stones and its inability to treat tissue lesions such as urinary-tract stenosis and tumors.

[Comparative study of two latest generation flexible ureterorenoscopes]. / Etude comparative de deux urétérorénoscopes souples de dernière génération.

INTRODUCTION AND OBJECTIVES: Miniaturization and development of flexible instruments have led to the development of flexible ureterorenoscopy. The objective of this study was to compare the capacities of active deflection of two latest generation flexible ureterorenoscopes and to evaluate alteration of deflection and flow of irrigating fluid in the presence of instruments in the operating channel. MATERIAL AND METHODS: Two ureterorenoscopes were evaluated in this study. The Karl STORZ Flex-X and the ACMI DUR-8 Elite. Comparison of deflection movements was performed ex situ by super-imposing all active movements of the two ureterorenoscopes. Alteration of deflection was performed by alternately placing an extraction or fragmentation instrument of variable dimensions in the operating channel. Alteration of flow was also assessed in the presence of the same instruments. RESULTS: The ex situ deflection capacities of the DUR-8 Elite flexible ureterorenoscope were more extensive than those of the Flex-X, but it was more complicated to manipulate. Alterations of deflection and flow of irrigation fluid were comparable for the two ureterorenoscopes. CONCLUSION: On the basis of these data, we can confirm that the two latest generation ureterorenoscopes present comparable capacities, but different functioning modalities. We therefore recommend that each operator test the two ureterorenoscopes to become familiar with their manipulation. Other studies are necessary to evaluate the optical properties, ease of use in clinical practice and fragility of these new ureterorenoscopes.

[Endoscopic lithotripsy and FREDDY laser technology. Initial experience]. / Intérêt et place de la lithotritie endocorporelle Nd:YAG en urétéroscopie souple et semi-rigide: une alternative au laser Holmium:YAG?

INTRODUCTION AND PURPOSE: FREDDY laser technology was developed for endocorporeal lithotripsy. The purpose of this study was to evaluate, based on our initial experience, the efficacy and place of this technology in the treatment of urinary calculi by ureterorenoscopy. (World of Medicine) to treat 26 patients (29 stones) by ureterorenoscopy. This was the second procedure for 25 stones: after ESWL (23 cases) or percutaneous nephrolithotomy (2 cases) and the first procedure for 4 stones. The mean stone diameter was 9 mm (range: 6-15 mm). Thirteen stones were situated in the kidney and 16 were in the ureter. Success of treatment was defined by the absence of residual fragments immediately after the operation or at one month on plain abdominal x-ray. RESULTS: Twenty-six stones were satisfactorily fragmented. At three months, 21 out of 26 (80.7%) patients were stone-free corresponding to 21 out of 29 (72.4%) stones). Failures concerned 8 stones (5 patients). For five stones, measuring more than 10 mm, residual fragments persisted at three months. For three other stones, two cystine stones and one calcium oxalate monohydrate stone, fragmentation was insufficient or even nonexistent for the cystine stones. The mean length of hospital stay was 1.5 days (range: 1-3 days). A ureteric perforation due to a stone impacted in the ureteric wall was observed. CONCLUSIONS: FREDDY laser endoscopic lithotripsy is a safe and effective method due to the wavelength used. This laser could constitute an alternative treatment option in view of its moderate cost and the fact that it is adapted to flexible ureterorenoscopy. However, it presents certain limitations in terms of fragmentation, particularly in the case of cystine stones, and cannot be used to treat solid lesions (urinary tract strictures and tumours).

Impact on active scope deflection and irrigation flow of all endoscopic working tools during flexible ureteroscopy.

OBJECTIVE: Flexible ureteroscopy is nowadays an alternative effective option for treatment of upper urinary tract stones, especially in the lower renal pole. Access in this case is often limited by active deflection capabilities of the instrument which is always deteriorated by the passage of different tools through the working channel. Insertion of them limits also the irrigation flow and so that the visibility. These deteriorations vary largely following the tool inserted. We performed an in vitro evaluation of deterioration of active deflection, possibility of tool insertion in maximal active deflection and irrigation flow in 6 different flexible ureteroscopes with almost all of tools available. METHODS: A total of 546 measures of maximal deflection, test of passage of tools in maximal deflection and measures of irrigation flow passage through the working channel were made on 6 different ureteroscopes, the ACMI DUR-8, the ACMI DUR-8 "Elite", the Karl Storz 11274 AA, the Karl Storz 11278 AU1 "Flex-X", the Wolf 7325.172 and the Olympus URF/P-3 without any tool inserted and with 22 different tools (14 extraction devices and 8 lithotripsy probes). RESULTS: Larger caliber tools resulted in more deflection degradation than smaller ones but it is more evident in case of use of non-nitinol tools instead of the nitinol ones. Generally lithotripsy probes affected active deflection more than nitinol extractions tools but different brand laser fibres present different results. Usually 1.6 and 1.9F electro hydraulic probes offer a slightly better deflection than does the 200micro laser fibre. Ballistic shock probes are so stiff that can not be used for treating lower renal pole stones. CONCLUSIONS: An array of different instruments are nowadays available for upper renal endoscopic treatment but they differ largely on stiffness and on obstruction to irrigation flow. Laser probes are very problematic to insert in the already deflected instruments, something that is less evident with the EHL probes and the smaller nitinol extraction tools. Irrigation flow is inversely proportional to the diameter of the tool inserted. Tools with a diameter of 3 French or more block totally the flow.

[Flexible double active deflection ureterorenoscopy]. / Urétérorénoscope souple à double déflexion active. Expérience initiale.

INTRODUCTION AND OBJECTIVE: Secondary deflection of a flexible ureterorenoscope (FUR) is a passive mechanism, which can only be performed under certain anatomical conditions. The objective of this study was to present a new double active deflection FUR and to assess its value based on our initial experience. MATERIAL AND METHODS: From October 2002 to February 2003, we performed flexible retrograde ureterorenoscopy in 30 consecutive patients (34 renal units) using a double active deflection FUR (ACMI DUR 8 Elite). Bilateral ureterorenoscopy was performed during the same operating time in four patients. Ureterorenoscopy was diagnostic for 9 patients (macroscopic haematuria, urinary tract tumour), and therapeutic for 21 patients (stones, urinary tract tumour, ureteropelvic junction stenosis with stone). The value of double deflection as well as the efficacy and morbidity of the technique were evaluated. RESULTS: The main indication for flexible ureterorenoscopy was the treatment of urinary stones (73.6%), followed by the diagnosis of macroscopic haematuria and urinary tract tumours (26.4%). Ureteric dilatation was necessary in 38.3% of cases. The use of active secondary deflection was essential in 20% of cases (7/34) for complete investigation of the pyelocaliceal cavities. Access to the lower calices was not possible in one patient with a left pelvic kidney. 19 patients with urinary stones had no fragments (79.2%) at the end of the operation, while 4 had residual fragments in the lower calices. The global success rate for all operations was 85% (29/34). Two patients developed acute pyelonephritis during the 48 hours after the procedure and another two patients experienced acute renal colic. CONCLUSIONS: Our study confirms the data of the literature on flexible ureterorenoscopy in terms of indications and efficacy. The URS DUR 8 Elite allowed complete exploration of the pyelocaliceal cavities in more than 97% of cases. The use of active secondary deflection was unnecessary for the majority of patients (80%), but it represents a major technical progress which should be taken into account in the design of future flexible ureterorenoscopes.

Pinball calculus in a ureterosigmoidostomy.

We report a complication during the treatment of lithiasis with extracorporeal shock wave lithotripsy in a patient with a ureterosigmoidostomy. This woman presented with renal colic bilaterally and renal insufficiency and was found to have an extremely mobile calculus. A significant gaseous reflux from the sigmoid colon was found to propel the solitary calculus in a retrograde fashion across the ureteroileal anastomosis up the ureter into one kidney, and then later, after re-descent to the level of the anastomosis, up into the opposite kidney. After several days of playing hide and seek with this migrating calculus, using extracorporeal shock wave lithotripsy, the patient became stone free.