Category: Clinical Stones: Ureteroscopy

MP32-2 - RIRS performed in situ for lower pole renal stones: can we achieve a good outcome?

Sun, Sep 23
2:00 PM - 4:00 PM

Introduction & Objective : Endourology is considerd the best treatment of stones located in the lower pole. When performing RIRS (retrograde intrarenal surgery) dislocation of the stone is usually suggested. The main reason of that is the high risk of ureteroscope damaging due the extreme and prolonged flexion. Little is known about efficacy of lower pole stones if treated in situ. Objective of this study was to evaluate the efficacy of RIRS with lithotripsy performed in situ in case of favorable anatomy with low risk of instrument damaging

Methods :

RIRS performed in a single Center from 2013 to 2017 were retrospectivley analized. Single stones 15 mm in the lower pole were selected. All the patients underwent a pre-operative CT scan or intraoperative pyelogram to study the anatomy of the lower calices. During this period we had decided to dislocate stones to the upper pole before lithotripsy only when the caliceal anatomy didn’t allow an easy and safe access the the stone. In all the other cases stones were treated in situ.  RIRS was considerd successful in case of stone free or CIRF (residual fragments ≤ 4 mm). Patients were followed one month after surgery by CT scan (if stone > 1 cm) or US. We created to groups of patients: in group A stones were treated in situ, in gropu B stones were dislocated before lithotripsy. Success rate and operative time were evaluated as primary outcomes. T-student , Mann-Whitney and Chi square tests were used for statistical analisys (SOFA system)

Results : Complete data were available for 93 patients. All the patients underwent laser lithotripsy using Sphinx Jr 30W Holuim laser system. Pre-operative stent was in situ in 44/93 cases (47.3%).  Stones were treated in situ in 61 cases (group A) and after dislocation in 32 (group B). Overall success rate was 80,6% (75/93): stone free 72% (67/93) and CIRF 8,6% (8/93). Group A and B were comparable for age (53,7 ± 13,3 vs  56,0 ± 14,2, p= 0,46), stone size (9,5 ± 2,9 vs 9,9 ± 2,6, p=0,49), Hunsfield unit (793 ± 262 vs 801 ± 252, p=0,82 ) and preopeative stenting (54% vs 34%, p=0,8). Operative time was similar beetwen two groups whereas success rate was significantly higher in group A.  Considering a subanalisys on stones ≤ 10 mm, this difference was reduced but still significant (Tab.1)

Conclusions : RIRS performed in situ for lower pole renal stones have a low success rate, even if the caliceal anatomy allowes an easy access to the stone. Success rate is low for smaller stones as well.  Considering the high risk of instrument ropture, the poor outcome and absence of a shorter operative time, to perform RIRS in situ for lower pole renal stones should always be avoided

Ettore Dalmasso

AO Santa Croce e Carle Cuneo
Cuneo, Piemonte, Italy

Orazio Maugeri

Cuneo, Piemonte, Italy

Diego Bernardi

Cuneo, Piemonte, Italy

Germano Chiapello

Cuneo, Piemonte, Italy

Claudio Dadone

Cuneo, Piemonte, Italy

Elisa Galletto

cuneo, Piemonte, Italy

Filippo Oppezzi

Cuneo, Piemonte, Italy

Mauro Mediago

Cuneo, Piemonte, Italy

Fabio Venzano

Cuneo, Piemonte, Italy

Giuseppe Arena

Cuneo, Piemonte, Italy