Efficacy of flexible fibreoptic ureteroscopy and Holmium laser in retrograde intrarenal surgery for calyceal calculi

Abstract

Urinary stones are one of the commonest pathology affecting kidneys1 and percutaneous nephrolithotomy (PCNL) is the most commonly performed minimally invasive procedure for renal stones today. Shock wave lithotripsy (SWL) is the treatment of choice for renal stones less than 2 cm in size.2 The success rate of SWL depends upon many factors, with the stone size and location being the most important ones. The requirement of multiple sessions and poor stone clearance rate of inferior calyceal calculi are few of the disadvantages of SWL for intrarenal calculi. Percutaneous nephrolithotomy has better clearance rate than SWL but is invasive with considerable patient morbidity. Less invasive than PCNL and more versatile than SWL, flexible ureteroscopy has emerged as an effective alternative for management of intrarenal stones. Retrograde intrarenal surgery (RIRS) using flexible ureteroscopes is comparatively a new modality for the treatment of renal calculi.2 With the availability of newer flexible ureteroscopes with high deflecting angles it is possible to access even the remote locations in kidney like inferior calices.3, 4 RIRS using flexible ureteroscopes has shown stone clearance rates better than SWL for renal stones less than 2 cm in size.5 The procedure though is slightly more difficult to perform, has advantage of clearing stones with fewer sittings and clearing SWL resistant calculi with minimal morbidity. Flexible ureteroscopy with Holmium YAG laser fragmentation and complete removal of fragments by baskets or graspers is the treatment of choice in specific occupations like airline or airforce pilots and in young girls to avoid scars. It has also been used in pregnancy.6, 7 Ureteroscopes are delicate instruments with optical fibres and a single 3–4 Fr instrumentation cum irrigation channel. The smallest instrument available is 6.5 Fr tip with 7.5 Fr at the base. Various accessories are required for a successful procedure.