STONE DISEASE

Frequency of Ureteroscope Damage Seen at a Tertiary Care Center
Carey RI, Gomez CS, Maurici G, Lynne CM, Leveillee RJ, Bird VG
Department of Urology, University of Miami and Jackson Memorial Hospital, Florida 33101, USA
J Urol. 2006; 176: 607-10

• 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.
  
  
• Editorial Comment
  This study supports the fragility of flexible ureteroscopes, though it suggests that newer generation endoscopes may be utilized for up to 48 procedures before requiring a major repair. The complexity of the case, need for treatment of the lower pole, use of holmium laser lithotripsy and patient anatomy are all important variables that determine the amount of stress placed on the ureteroscope during a procedure, therefore it is difficult to say whether 50 cases should be expected with a new ureteroscope. However, the most important observation from this study is that once a ureteroscope returns from a major repair, this refurbished endoscope is prone to breakage a second time, at a much more rapid rate – such that less than 10 cases can be expected. Evaluating the cost of repair vs. purchase of a new scope it appears that the cost per case (US$300 for a new scope, US$536 for a refurbished scope) favors discarding the broken scope and starting afresh.

Dr. Manoj Monga
Professor, Department of Urology
University of Minnesota
Edina, Minnesota, USA