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

Abstract Introduction Retrograde intrarenal surgery (RIRS) is the ideal complementary approach to flexible ureterorenoscopy (URF) 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. 28 patients had a single kidney stone and 7 had multiple stones. Approach Flexible ureterorenoscopy, 7.5 Fr (Flex-X2 ® , Karl Storz) by means of a ureteral access sheath. Holmium laser lithotripsy (Calculase ® , Karl Storz) using 200 and 365 μ fibres. Fragment extraction with 1.7 Fr nitinol baskets (N-gage, Cook). In cases of excessive 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 “miniperc” sheath (Ultrax-x ® 18Fr, Cook) placed using the percutaneous endoscopic technique 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 excessive stone burden and/or alteration in their pyelocaliceal anatomy, we performed active lavage of the renal cavities applying the aforementioned percutaneous technique. The mean postsurgery 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 >1.5 cm kidney stones. Lavage ofthe renal cavities helps to eliminate stone fragments, reducing the possibility ofretreatment.