Accuracy of Patient Reported Stone Passage for Patients With Acute Renal Colic Treated in the Emergency Department

Abstract

Objective: To study patients who initially presented to the Emergency Department with acute renal colic to determine if patient-reported stone passage detects stone expulsion as accurately as follow-up computed tomography (CT) scan.

Methods: This is a secondary analysis of a multi-center prospective trial of patients diagnosed by a CT scan with a symptomatic ureteral stone <9 mm in diameter. Patient-reported stone passage, defined as capture or visualization of the stone, was compared to CT scan-confirmed passage performed 29-36 days after initial presentation.

Results: Four-hundred-three patients were randomized in the original study and 21 were excluded from this analysis because they were lost to follow-up or received ureteroscopic surgery. Of the 382 remaining evaluable patients, 237 (62.0%) underwent a follow-up CT scan. The mean (standard deviation) diameter of the symptomatic kidney stone was 3.8 mm (1.4). In those who reported stone passage, 93.8% (91/97) demonstrated passage of the symptomatic ureteral stone on follow-up CT. Of patients who did not report stone passage, 72.1% (101/140) demonstrated passage of their stone on follow-up CT.

Conclusions: For patients who report capture or visualization of a ureteral stone, a follow-up CT scan may not be needed to verify stone passage. For patients who do not capture their stone or visualize stone passage, imaging should be considered to confirm passage.