Abstract
Purpose To present attributes of currently available flexible　ureteroscopes to define the best flexible ureteroscope for upper tract urothelial carcinoma (UTUC) treatment.

Materials and methods：
Scopus and Medline databases were searched for articles relating to performance of flexible ure -teroscopes. A consensus for final inclusion of articles judged to be relevant for UTUC treatment was　reached between the authors. Instrument characteristics were extracted from manufacturers’ product brochures.

Results ：
Smaller cross-sectional size of instruments is associated with increased probability for successful primary access to the upper urinary tract. The smallest flexible ureteroscopes are fiberoptic scopes. Smaller ureteroscopes also allow compara -tively increased irrigation flow at constant intrarenal pressure. Digital flexible ureteroscopes achieve superior image quality
compared to their fiberoptic
counterparts, at the price of lower end-deflection ability. Image enhancement technologies such as narrow-band imaging (NBI), photodynamic diagnosis (PDD) and Image 1-S (formerly SPIES) are based on subjective image interpretation by the operator. NBI and PDD significantly increase tumor detection rate. The highest subjective image quality score of the Image 1-S technology is reached by the “Clara + Chroma” mode. Single-use　ureteroscopes offer potential
advantages over reusable scopes, including sterility, absence of contamination, immediate availability and exemption of previous instrument wear.

Conclusions：
Miniaturization, digital image caption and image enhancement technologies seem to be the major determinants
defining the best flexible ureteroscope for UTUC treatment. The impact of further factors, such as distal tip design, torque, working channel position, risk of contamination, as well as upcoming technological innovations should be evaluated in randomized controlled trials.

Keywords ：
Upper tract urothelial carcinoma · Ureteroscopy · Miniaturization · Digital · Image enhancement technology

目的：
上部尿路上皮癌（UTUC）治療に最適な軟性尿管鏡を定義するために、現在利用可能な（市場に出ている）軟性尿管鏡の属性を提示すること。

対象および方法：軟性尿管鏡の性能に関連する文献をScopusおよびMedlineデータベースで検索し、UTUC治療に関連があると判断されたものを、著者らの合意により最終的に決定した。器具の特性については、メーカーの製品カタログから収集した。

結果：
器具の断面が小さいほど、上部尿路へのprimaryアクセスの成功確率が高くなる。最小の軟性尿管鏡は光ファイバースコープである。小さい尿管鏡は、一定の腎内圧で比較的量の多い灌流も可能となる。デジタル軟性尿管鏡は、光ファイバーのものに比べ、先端部偏向能力は劣るものの、優れた画質を提供する。狭帯域光観察（NBI）、光線力学的診断（PDD）、Image 1-S（以前のSPIES）等の画像強調技術は、操作者の主観的画像解釈に基づいている。NBIおよびPDDは腫瘍検出率を顕著に高め、Image 1-S技術の主観的画質スコアは、”Clara + Chroma”モードで最高スコアに到達するほどである。使い捨て尿管鏡は、無菌性、汚染なし、即時利用が可能、器具の前回使用による摩耗なし等、再利用可能のものに比べ潜在的利点がある。


結論：
小型化、デジタル画像キャプション、画像強調技術は、UTUC治療における最適な軟性尿管鏡を定義する上で、主要な決定要因であると思われる。ランダム化比較試験において、遠位先端部（チップ）の設計、トルク、ワーキングチャネルの位置、汚染リスク、並びに今後の技術革新等、さらなる要因の影響を評価する必要がある。
キーワード：Upper tract urothelial carcinoma ・ Ureteroscopy ・ Miniaturization ・ Digital ・ Image enhancement technology

Abstract
Purpose:
Careful decontamination and sterilization of reusable flexible ureteroscopes used in　ureterorenoscopy cases prevent the spread of infectious pathogens to patients and technicians. However, inefficient reprocessing and
unavailability of ureteroscopes sent out for repair can contribute to expensive operating room (OR) delays. Time driven activity-based costing (TDABC) was applied to describe the time and costs involved in reprocessing.

Materials and Methods:
Direct observation and timing were performed for all steps in reprocessing of reusable flexible ureteroscopes following operative procedures. Estimated times needed for each step by which damaged ureteroscopes identified during reprocessing are sent for repair were characterized through interviews with purchasing analyst staff. Process maps were created for reprocessing and repair detailing individual step times and their
variances. Cost data for labor and disposables used were applied to calculate per minute and average step costs.

Results:
Ten ureteroscopes were followed through reprocessing. Process mapping for ureteroscope　reprocessing averaged 229.0 – 74.4 minutes, whereas sending a
ureteroscope for repair required an estimated 143 minutes per repair. Most steps demonstrated low variance between timed observations. Ureteroscope drying was the longest
and highest variance step at 126.5 – 55.7 minutes and was highly dependent on manual air flushing through the ureteroscope working channel and ureteroscope positioning in the drying cabinet. Total costs for reprocessing totaled $96.13 per episode, including the cost of labor and disposable items.
Conclusions: Utilizing TDABC delineates the full spectrum of costs associated with ureteroscope reprocessing and identifies areas for process improvement to drive value-based care. At our institution, ureteroscope drying was one clearly identified target area. Implementing training in ureteroscope drying technique could save up to 2 hours per reprocessing event, potentially preventing expensive OR delays.

Keywords:
ureteroscope, sterile processing, cost analysis, time-driven activity-based costing

目的：
尿管腎鏡治療における症例で使用する、リユーザブル軟性尿管鏡の入念な洗浄・消毒および滅菌は、患者や技術者への感染性病原体の拡大を防ぐ。しかし、非効率的な再処理や修理による尿管鏡不足の事態は、費用のかかる手術室（OR）遅延の一因となり得る。そこで、時間主導型活動基準原価計算（TDABC）を適用し、再処理にかかる時間と費用を明らかにした。

対象および方法：
作業工程に従ったリユーザブル軟性尿管鏡のすべての再処理ステップにおいて、直接観察および時間計測を実施した。再処理中に特定された破損尿管鏡の修理手配における各ステップの推定時間は、購買アナリスト職員とのインタビューを通して明確にした。個々のステップ時間とその分散を具体化し、再処理および修理に関するプロセスマップを作成した。人件費および使用した使い捨て用品（消耗品）のコストデータを用いて、1分当たりの平均ステップ費用を算出した。

結果：
尿管鏡10台について再処理作業を遂行した。プロセスマップによると、尿管鏡の再処理は平均229.0±74.4分、修理（破損特定と修理手配）は1件につき推定143分を必要とした。ほとんどのステップは時限観察間の分散が小さい中、乾燥作業が126.5±55.7分で最も長く、分散が最も大きかった。このステップは、尿管鏡のワーキングチャネル内へ手動で空気を流す作業と、乾燥キャビネットに配置する作業にかなり依存していた。再処理の総費用は、人件費と使い捨て用品費を含め、1回当たり$96.13であった。

結論：
TDABCを利用することで、尿管鏡再処理関連コストの全体像が浮き彫りになり、価値ベースの医療を推進するためのプロセス改善領域が特定される。私達の施設では、尿管鏡の乾燥作業がその改善領域として明確に特定された。尿管鏡の乾燥技術におけるトレーニングを実施することで、再処理1回当たり最長2時間節約でき、費用のかかるOR遅延を回避できる可能性がある。



キーワード：ureteroscope, sterile processing, cost analysis, time-driven activity-based costing

Purpose:
The significant improvements in flexible ureterorenoscopes have made flexible ureteroscopy the main
treatment modality to target upper urinary pathologies. The purpose of this study was to critically evaluate all literature concerning the cost-effectiveness of flexible ureteroscopy
comparing single-use with reusable scopes.

Methods:
A systematic online literature review was performed in PubMed, Embase
and Google Scholar databases. Two separate urologists (GSM and FCT) performed the online search and reviewed all papers considered suitable and relevant for this analysis. Because of the paucity of high quality publications, not only prospective
assessments but also case control and case series studies were included in the final analysis. All factors potentially affecting surgical costs or clinical outcomes were considered in the analysis.

Results:
741 studies with the previously elected terms were found. Of those, 18 were duplicated and 77 were not related
to urology procedures and were excluded. Of the remaining 646
studies, 59 published between 2000 and 2018 were considered
of relevance to the pre-defined queries and were selected for
further analysis. Stone free and complication rates were similar
between single-use and reusable scopes. In special, urinary tract
infection rate following flexible ureteroscopy is not inferior if asingle-use device is used instead of a reusable scope. Operative time was in average 20% shorter if a digital scope was used, single-use or not. There is a suggestion that the learning curve
is shorter with single-use devices but this is not consistent in the literature. Surgeon expertise impacts the longevity of the flexible scope. Reusable digital scopes seem to last longer than optic ones, though scope longevity is very variable worldwide. New scopes usually last three to four times more than refurbished ones and
single-use ureterorenoscopes have good resilience throughout long cases. Both sterilization method and cleaning process impact scope longevity, the best results being achieved with Cidex and a dedicated nurse to take care of the sterilization process. The main factors that negatively impact device longevity regarding patient and disease are lower pole pathologies, large stone burden and non-use of a ureteral access sheath.

Conclusions:
The cost-effectiveness of a flexible ureteroscopy program is dependent of
several aspects that must be　considered when deciding whether
to choose between a single-use and a reusable ureterorenoscope.
Disposable devices are already a reality and will progressively
become the standard as　manufacturing price falls significantly.

Keywords:
Ureteroscopy;　Ureteroscopy/instrumentation;
Nephrolithiasis; Cost-benefit analysis; Equipment reuse/economy;
Recycling/economy.