Resorlu, Unsal et al reported the Resorlu-Unsal Stone Score (RUSS) for patients with nephrolithiasis. This can be used to predict the outcome following retrograde intrarenal surgery. The authors are from Kecioren Training and Research Hospital and Ankara University in Turkey.
Parameters:
(1) stone size in mm
(2) location of the stone and infundibulopelvic angle (IPA) in degrees
(3) number of stones in different calyces
(4) renal anatomy
|
Parameter |
Finding |
Points |
|
stone size |
<= 20 mm |
0 |
|
|
> 20 mm |
1 |
|
location of stone and IPA |
lower pole AND IPA < 45° |
1 |
|
|
other |
0 |
|
number of stones |
1 stone OR 1 calyx |
0 |
|
|
2 or more stones in different calyces |
1 |
|
renal anatomy |
normal |
0 |
|
|
abnormal (pelvic kidney, horseshoe, other) |
1 |
where:
• Infundibulopelvic angle (IPA) is the inner angle formed by (central axis of the the lower pole infindibulum) and (ureteropelvic axis).
• Stone size presumably refers to the largest stone.
• While the text states that the maximum score is 4, Table 4 suggests that larger stones would be scored higher: 30 to 39 mm 2 points, 40 to 49 cm 3 points, etc.
total score =
= SUM(points for all 4 parameters)
Interpretation:
• minimum score: 0
• maximum score: 4
• The lower the score the greater the stone-free rate following retrograde intrarenal surgery.
|
RUSS |
Stone Free |
|
0 |
97% |
|
1 |
85% |
|
2 |
70% |
|
3 or 4 |
27% |
Specialty: Nephrology, Clinical Laboratory
ICD-10: ,
