Treatment Of Upper Tract Calculi Research Articles

Ureteral Avulsion Associated with Ureteroscopy: Insights from the MAUDE Database.

Flexible and semirigid ureteroscopy (URS) are widely performed for the treatment of upper tract calculi and tumors. Ureteral avulsion is a rare, but devastating complication of endoscopic stone removal having multiple possible etiologies. Awareness and avoidance of this rare complication depend on identifying responsible mechanisms. This study examines the situations in which ureteral avulsion occurs as described anonymously in the Manufacturer and User facility Device Experience (MAUDE) database. The MAUDE database was systematically reviewed to account for all reported complications of flexible and semirigid URS. Keywords "ureteroscopy, injury, death, malfunction and other" were entered in the database and medical device reports were reviewed to capture any cases resulting in ureteral avulsion. Attention was paid to the type of ureteroscope involved and the mechanism for avulsion. A total of 104 entries were found detailing the reported complications of flexible and semirigid URS. Ureteral avulsion was clearly noted in six reports with flexible (2) and semirigid ureteroscopes (4). Potential mechanisms included locked deflection of a flexible ureteroscope (1), bunching of the distal bending rubber in a flexible ureteroscope (1), scabbard avulsion (3), and stone basketing (1). Although the incidence of ureteral avulsion cannot truly be determined from this study, some potentially novel mechanisms for this rare complication are observed. This may target future educational efforts to maximize awareness and avoidance of this complication.

Contemporary Surgical Trends in the Management of Upper Tract Calculi

Upper tract nephrolithiasis is a common surgical condition that is treated with multiple surgical techniques, including shock wave lithotripsy, ureteroscopy and percutaneous nephrolithotomy. We analyzed case logs submitted to the ABU by candidates for initial certification and recertification to help elucidate the trends in management of upper tract urinary calculi. Annualized case logs from 2003 to 2012 were analyzed. We used logistic regression models to assess how surgeon specific attributes affected the way that upper tract stones were treated. Cases were identified by the CPT code of the corresponding procedure. A total of 6,620 urologists in 3 certification groups recorded case logs, including 2,275 for initial certification, 2,381 for first recertification and 1,964 for second recertification. A total of 441,162 procedures were logged, of which 54.2% were ureteroscopy, 41.3% were shock wave lithotripsy and 4.5% were percutaneous nephrolithotomy. From 2003 to 2013 there was an increase in ureteroscopy from 40.9% to 59.6% and a corresponding decrease in shock wave lithotripsy from 54% to 36.3%. For new urologists ureteroscopy increased from 47.6% to 70.9% of all stones cases logged and for senior clinicians ureteroscopy increased from 40% to 55%. Endourologists performed a significantly higher proportion of percutaneous nephrolithotomies than nonendourologists (10.6% vs 3.69%, p <0.0001) and a significantly smaller proportion of shock wave lithotripsies (34.2% vs 42.2%, p = 0.001). Junior and senior clinicians showed a dramatic adoption of endoscopic techniques. Treatment of upper tract calculi is an evolving field and provider specific attributes affect how these stones are treated.

Retrograde intrarenal surgery for the treatment of renal stones in children: Factors influencing stone clearance and complications

BackgroundRetrograde intrarenal surgery (RIRS) is a known option for the treatment of upper tract calculi with an excellent success. However, the reports of RIRS in prepubertal children are limited. In this study, we evaluated the factors which affected the success rate and the complications of RIRS at renal stone treatment in childhood. MethodsWe retrospectively reviewed the records of children under 14 years old who underwent RIRS for renal stone disease between January 2009 and December 2012. Patients’ age, gender, body mass index (BMI), stone size, stone location, stone number, intraoperative complications, stone free status, postoperative complications were recorded. ResultsThere were 80 ureterorenoscopic procedures performed in 58 renal units of 47 children (23 males and 24 females). The patients’ ages ranged from 8 months to 14 years (mean age 4.7±3.4years). There was a difference in the distribution of symptoms in age groups. UTI was higher in the 1–4years age group, abdominal pain was seen mostly in children aged 5–14years. Multiple stones (included staghorn stone) were noted in 60.4% of patients. In 27.6% of patients, ureteral stones were accompanied by renal stones in our series. In the infancy group, cystine and staghorn stones were more frequently seen, mostly bilateral. After a single ureteroscopic procedure for intrarenal stones in children, we achieved stone free status in 50.9% of the ureters (n=26). After the repeated sessions, the stone clearance rate reached to 85.1%. ConclusionRetrograde intrarenal surgery can be used as a first line therapy to treat renal stones in children. This is especially important if an associated ureteral stone is present that requires treatment; or in patients with cystinuria, which is not favorably treated with ESWL. Complications were seen more frequently in patients with cystine stones. Extravasation was noted more frequently in patients admitted with UTIs. There was a significant relationship between the conversion to open procedures and the age groups, with most procedures occurring in infancy. The parents should be informed about the probability of multiple procedures to achieve stone free status.

THE EFFECT OF FAT AND NON-FAT COMPONENTS OF THE SKIN-TO-STONE DISTANCE ON SHOCKWAVE LITHOTRIPSY SUCCESS

It is the nature of endoscopy to begin with diagnostic applications and then to progress with improvements in technology to therapeutic applications. Retrograde upper urinary tract endoscopy has similar origins. In regard to ureteroscopy, it began with Victor Marshall24 who first described in 1964 the use of a flexible fiberscope placed in the ureter to visualize an obstructing calculus. The therapeutic ureteroscopy of today is based on treating the stone burden by converting it to small passable fragments.4, 23 This progression in technology has continued with the development of new endoscopes and various forms of energy that can be used not only for lithotripsy but also to treat upper tract tumors and ureteral stricture disease.9, 21Current treatment of upper tract calculi is based on focusing shock waves onto a stone and fragmenting it into more easily passable pieces (i.e., Extracorporeal Shockwave Lithotripsy [ESWL]) or on direct endoscopic inspection and conversion of the stone burden into fine dust and small fragments with intracorporeal lithotripsy. Shock wave lithotriptors also have evolved, requiring less anesthesia, in part, because of smaller focal zones and lower delivered energy. With these changes, the indications for treatment have narrowed. Large stones, those associated with high-grade ureteral obstruction, and those for which fluoroscopic localization is difficult, are best treated endoscopically.6 If there is poor fragmentation noted with shock wave lithotripsy, conversion to endoscopic techniques also has a significantly higher success rate with minimal morbidity.19 There has been recent debate on whether most upper tract stones would be treated better in a retrograde endoscopic way, in which there is more certainty of proper fragmentation and clearance.The current treatment algorithm used for those patients with moderately sized, uncomplicated upper urinary tract calculi is based on ESWL monotherapy performed under intravenous sedation. All other stones would represent more complex presentations and should be treated endoscopically.18 If there is a greater anesthetic requirement than intravenous sedation for the shock wave treatment or if placement of a ureteral catheter is required to drain a completely obstructed upper urinary tract, the more definitive endoscopic treatment can be considered rather than pursuing shock wave lithotripsy.The techniques and instrumentation currently used for retrograde ureteroscopic lithotripsy are presented in this article. A large series of ureteroscopic treatments performed with current small-diameter endoscopes also are reviewed. A large, prospectively accrued database of upper urinary calculi treated ureteroscopically with the Holmium laser also is presented to highlight the techniques.

Impact of flexible ureterorenoscopy in current management of nephrolithiasis

Flexible ureterorenoscopy continues to assume an increasing role in the armamentarium of the endourologist. Here, we summarize some of the important papers over the past 12-18 months that continue to define its place in the treatment of upper tract calculi. We concentrate on the indications for flexible ureterorenoscopy for upper tract calculi, and discuss the techniques and strategies that can be employed in different situations, including its use in combination with extracorporeal shockwave lithotripsy and percutaneous nephrolithotomy. The developing technology behind flexible ureterorenoscopy is also discussed. Flexible ureterorenoscopy is emerging as one of the mainstays of treatment of upper tract calculi, rather than as a technique for the exclusive use of the enthusiast. Technical advances in image quality and in making the scopes more durable are likely to lead to an increasing use of this technique in more urology departments in the future.

Flexible Ureterorenoscopy: Report of 97 Consecutive Procedures

Ninety-seven flexible ureteroscopy procedures were carried out in 87 patients, 80 for the treatment of upper tract calculi, 14 for diagnostic purposes only, and 3 for ureteral stricture dilation. Access to the ureter was not successful in five patients. Sixty-seven of the remaining procedures (72%) were carried out successfully with one flexible ureteroscopic procedure. An additional six patients were treated successfully with two procedures. Therefore, the overall success rate for flexible ureteroscopy alone was 79%. Following transureteroscopic treatment of upper tract stones, eight patients (9%) had retained fragments. All patients were rendered stone free by additional procedures. Seven patients (8%) with upper tract calculi were either treatment failures or were lost to follow-up. There were 11 minor and 4 major complications. Nine of the minor complications resolved without additional therapy. Two of the major complications involved delayed development of a distal ureteral stricture, and two were perforations that resolved after ancillary endourologic treatment.

Calculation of Stone Volume and Urinary Stone Staging with Computer Assistance

Stone volume is one of the most important factors in treatment outcome of upper tract urinary stones and should be taken into account as exactly as possible. Therefore, we took 50 urinary stones from an inhouse stone bank and measured each stone's longest axis, the sum of the longest axes in branched stones, and the total area with an image analyzer. Stone volume was determined on the basis of displacement of water. The plot of stone area against stone volume had the least scattering. Using a nonlinear least-squares computer program, the equation volume = 0.6 (area)1.27 was found to yield the best fit with a coefficient of determination (R2) of 0.97. A computer program was written in BASIC to measure the stone area from a roentgenogram using a sonic digitizing stylus. The program calculates the stone volume and integrates factors similar to those of the first version of the stone staging system PICA (J Urol 1987; 138:253). We suggest that such a computer-assisted staging system be incorporated into studies evaluating treatment of upper tract calculi to achieve better coherence in design and data analysis.