Retrograde intrarenal surgery for lower pole renal calculi smaller than one centimeter

Abstract

Objectives:Recently there has been an increasing interest in the application of retrograde intrarenal surgery (RIRS) for managing renal calculi. In this review we discuss its application for the management of lower calyceal (LC) stones less than 10 mm in maximum dimension.Materials and Methods:Literature was reviewed to summarize the technical development in flexible ureterorenoscopy and its accessories. Further, the indications, outcome and limitations of RIRS for LC calculi < 1 cm were reviewed.Results:Use of access sheath and displacement of LC stone to a more favorable location is increasingly employed during RIRS. Patients who are anticoagulated or obese; those with adverse stone composition and those with concomitant ureteral calculi are ideally suited for RIRS. It is used as a salvage therapy for shock wave lithotripsy (SWL) refractory calculi but with a lower success rate (46-62%). It is also increasingly being used as a primary modality for treating LC calculi, with a stone-free rate ranging from 50-90.9%. However, the criteria for defining stone-free status are not uniform in the literature. The impact of intrarenal anatomy on stone-free rates after RIRS is unclear; however, unfavorable lower calyceal anatomy may hamper the efficacy of the procedure. The durability of flexible ureteroscopes remains an important issue.Conclusions:RIRS continues to undergo significant advancements and is emerging as a first-line procedure for challenging stone cases. The treatment of choice for LC calculi < 1 cm depends on patient's preference and the individual surgeon's preference and level of expertise.

Lower Pole Midsize (1–2 cm) Calyceal Stones: Outcome Analysis of 56 Cases

“…RUR is now a well-established procedure to treat LP stones with a low incidence of complications [21]. Obese patients or those with noncorrected coagulopathy and those with hard stones that fail with SWL are ideally indicated for the ureteroscopic approach [4]. RUR can be used as a salvage therapy after failure with SWL.…”

“…The impact of intrarenal anatomy on stone-free rates after RIRS is unclear; however, unfavorable lower calyceal anatomy may decrease the efficacy of the procedure. The cost of instruments and durability of flexible ureteroscopes are also important issues [4,19,23,24]. …”

“…This is due to advancements in fiber optics and the availability of small-sized instrumentations that enable the urologist to perform complex maneuvers within the upper urinary tract. This has been supported by an increasing interest in retrograde intrarenal surgery (RIRS) for the management of renal calculi [4]. …”

Possibilities of retrograde intrarenal surgery in the treatment of renal lower pole stones in children

“…Those patients were selected for percutaneous nephrolithotomy. The other option is open surgery, but that kind of treatment is no longer in the protocol for surgical treatment of nephrolithiasis in our institution [13][14][15] .…”

Lower Pole Stone Management

“…Reported stone free rates range from 532% to 87% in various studies [40][41][42]. RIRS is a reasonable approach for lower pole lithiasis, especially in obese individuals, patients on anticoagulation, concomitant ureteral calculi and bilateral occurrence [43,44]. Based on the available literature, flexible URS seems to have comparable efficacy as ESWL for stones <15 mm [5,6].…”