[Retrograde intrarenal surgery (RIRS). Technical complement for cases of acute lithiasis].

INTRODUCTION

Washing the renal cavities using minipercutaneous surgery shaft is an ideal technical procedure for retrograde intrarenal surgery (RIRS) when lithiasic fragmentation is significant or if the anatomy of the renal cavities may obstruct the spontaneous elimination of fragments.

MATERIALS AND METHODS

we performed 37 RIRS on 35 patients with renal lithiasis (14 men, 21 women) with a mean age of 56 (range 33-72) years, divided into two groups in accordance with the size of their kidney stones. Group A, 23 patients with lithiasis <1.5 cm; Group B, 12 cases with lithiasis >1.5 cm. 28 patients had a single kidney stone and 7 had multiple stones.

APPROACH

Flexible uretrorenoscopy, 7.5 Fr (Flex-X(®, Karl Storz) by means of a ureteral access sheath. Holmium laser lithotripsy (Calculase®, Karl Storz) using 200 and 365 micrometer fibres. Fragment extraction with 1.7 Fr nitinol baskets (N-gage, Cook). In cases of significant fragmented stone burden, the renal cavities were washed with low-pressure fluid irrigation using a ureteral access sheath, which was collected together with the stone fragments carried by the "mini-perc" sheath (Ultrax-x® 18Fr, Cook; Rusch, 14 Fr) placed under radiologic and endoscopic control at the level of the calyx-papilla selected for fragment drainage.

RESULTS

the mean diameter for group A was 9.13 (range 5-13) mm and 20.25 (range 16-28) mm for group B. The overall mean operating time was 81 (range 30-160) min. Group A required 66.43±35.18 min. and group B 107.5±46.73 min. (p=0.006). The rate of absence of stones immediately after surgery was 83.2%, 93.1% at 3 months (95.6% for A and 83.3% for B; p=0.217). In no case was ureteral stenosis observed as a result of the use of ureteral access sheaths. In 7 group B patients (58.3%) with acute lithiasis and/or alteration in their pyelocaliceal anatomy, we performed active lavage of the renal cavities applying the aforementioned percutaneous technique. The mean post-surgery hospital stay was 2.1 (range 1-4) days. There were post-surgery complications (Clavien 1) in 7 patients (20%). Two patients required a second FURS.

CONCLUSIONS

RIRS can be effective treatment for renal lithiasis >1.5 cm. Lavage of the renal cavities helps to eliminate stone fragments, reducing the possibility of retreatment.