Role of flexible uretero-renoscopy in management of renal calculi in anomalous kidneys: single-center experience.

Abstract

Flexible uretero-renoscopy (FURS) is an accepted modality for management of renal calculi in orthotopically placed kidney. Though it has been used in management of calculi in anomalous kidneys, the literature is scarce. To define the role of FURS in the management of stones in anomalous kidneys. We performed a retrospective analysis of all the patients with anomalous kidneys who primarily underwent FURS from January 2010 to December 2015 at our institute. In our study, we included patients with anomalies of lie, fusion and rotation. A total of twenty-five patients with twenty-five renal units having renal calculi in anomalous kidneys were evaluated. Indications for FURS included stone size less than or equal to 2cm, contraindication to PCNL like bleeding tendencies, patients on anticoagulants or patients who refused ESWL and PCNL. Complete clearance of stone was defined as no residual fragment greater than 2mm at the end of 4weeks. The parameters evaluated were patient demographics, type of renal anomaly, stone size, location, laterality, patient's presentation, need for preoperative stenting, operative time, need for postoperative DJ stent, hospital stay, analgesic requirement, number of stages or auxiliary procedures required for stone clearance, success rate and complications. Twenty-five patients with calculi in anomalous kidneys were managed with FURS. These 25 patients had a total of 37 stones. Out of 25 patients, 14 had ectopic kidneys with 19 stones, 5 had malrotated kidneys with 6 stones, 5 had horseshoe kidneys with 11 stones and one had a left-to-right crossed fused ectopia with a single stone. Average age of presentation was 38.28±12.59years. Majority of the patients had the stones located in pelvis (n=11) or lower calyx (n=11). Eight stones were in middle calyx (n=8), five in upper calyx (n=5) and two in upper ureter (n=2). Fifteen patients had a single stone, and 10 of them had 2 or more stones. Average size of stone was 14.71±4.11mm and average density being 1210.8±237.7 Hounsfield units. Five patients had a preplaced DJ stent. Average Operative time was 74±21.2min, and patients had an average hospital stay of 59.48±17.8h. DJ stent was placed postoperatively in 21 patients, and four were managed with a ureteric catheter. Complete clearance was achieved in 22 (88%) patients, three patients required two stages and one required the third stage. Three patients (12%) could not be managed with FURS and required percutaneous stone clearance. Primary FURS is an effective and less invasive modality for management of renal calculi less than 2cm in kidneys with anomalies of lie, fusion and rotation. It can offset the low clearance rate and high complication rate of ESWL and PCNL, respectively. Ureteral access sheath is an important tool to overcome anatomical challenges of anomalous kidney. Basket and Laser are indispensable accessories for FURS in anomalous kidneys.