الفهرس 
Endoscopic anatomy of the ureterOnly 14 pages are availabe for public view
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Abstract
Endoscopic management of urinary calculi is the standard therapy world wide with the improvement in endoscopic design and miniaturization that allow surgeons to access calculi through out the collecting system and fragmenting in to extractable or passable pieces by different types of lithotripsy.
Multiple types of stone lithotripsy are used in stone fragmentation as E.H.L., ultrasonic and recently laser is used.
The holmium: yttrium aluminum garnet (Ho: YAG) laser was introduced into urologic clinical practice in the early 1990s. Its excellent ablative, cutting, and coagulating abilities have made it one of the most versatile and popular surgical lasers. Because it can be transmitted through flexible silica quartz fibers as small as 200 mm, this laser is particularly well suited for ureteroscopy. The 2100 nm emitted light is strongly absorbed by water as well as by urinary calculi of all chemical compositions.
This renders the holmium laser an effective lithotripter for all stone types, including hard cystine and calcium oxalate monohydrate stones. The holmium laser boasts an excellent efficacy and safety profile, and has been widely adopted as a first line lithotripter.
Despite the successful outcome of URS, surgeons often experience difficulties with stone fragmenting during the URS procedure, which requires high laser energy.
Although the stone-free rate and operative time are often evaluated when analyzing URS using a Ho:YAG laser, there have been few reported evaluations of the association between TLE used to fragment stone and preoperative findings, including stone Size expressed by the maximum diameter measured in mm, stone attenuation values measured using average Hounsfield units (HUs), presence of hydronephrosis, tissue rim sign, sex, age and laterality estimated by non contrast spiral computed tomography and the time of operation needed.