[Risk factors for contrast extravasation in renal colic].

Introduction: Non-traumatic ruptureof the pyeloureterocaliceal system (PUC) is anuncommon clinical entity. The most frequent cause isureteral obstruction due to lithiasic pathology, whichis present in up to 75%. To our knowledge, there isno description in the literature of the possible factorsassociated with this event. Our objective is to analyzethe variables associated with intravenous contrastextravasation in patients with renal colic due to singleureteral lithiasis. MATERIALS AND METHODS: We performed aretrospective, descriptive analysis of a series ofpatients who, in the context of renal colic, presentedendovenous contrast extravasation throughthe urinary system in computed tomography (CT).Patients with single ureteral lithiasis without otherassociated pathology were included. A comparisonof the samples from the group with contrast leakage(group 1) with an equal number of consecutiveCT scans without contrast leakage (group 2) in patientswith renal colic lithiasis was performed in alogistic regression model to identify risk factors forcontrast leakage.

Results: There were 117 cases of contrast leakagefrom January 2013 to July 2018. Eighty-sixpercent of the lithiases were 5 mm and 79% werelocated in the lower ureter. 72% of patients presentedwith intrarenal pelvis. In the univariate analysisboth location in lower ureter, lithiasis 5 mm, andintrarenal pyelic anatomy increased the probabilityof extravasation. In multivariate model, 5 mmlithiasis increased five times the risk of extravasationcompared to larger ones, the location in distalureter increased three times and the anatomy withintrarenal pelvis increased two times compared toother location and extrarenal pelvis, respectively, ina statistically significant way the risk of presentingcontrast leakage.

Conclusion: In this series, we found an increasedrisk of contrast leakage in a lithiasic renalcolic in patients with intrarenal pelvic anatomy,with lithiasis less than or equal to 5 mm and locatedin the lower ureter.