Predicting Ureteral Stone Passage: Size vs. Ureteral Wall Thickness "Presentation" - Seyedamirvala Saadat

August 15, 2024

At the World Congress of Endourology and Uro-Technology, Seyedamirvala Saadat presents a study examining factors predicting spontaneous ureteral stone passage. The research, involving 199 patients with acute renal colic, assesses various stone characteristics and ureteral wall thickness using non-contrast CT scans. Initial univariate analysis shows that longer, wider, and denser stones surrounded by thicker ureteral walls have a lower likelihood of spontaneous passage. However, multivariate analysis reveals that only the largest stone linear dimension remains a significant predictor.

Biographies:

Seyedamirvala Saadat, Urologist, Department of Urology, University of California, Irvine, CA


Read the Full Video Transcript

Seyedamirvala Saadat: Dr. Judy, Dr. Terry, members, and guests. Today, the most reliable indicator of a spontaneous passage of a ureteral stone has been the maximum axial linear size of the stone. A recent meta-analysis suggested that ureteral wall thickness measured on a non-contrast CT scan could be an inverse indicator of spontaneous ureteral stone passage.

We sought to assess if ureteral wall thickness taken alone or in combination with the stone's size would actually improve the predictability of spontaneous stone passage. At our institution, 199 patients with acute renal colic who opted for a trial of spontaneous stone passage were enrolled. Each stone's dimension, volume, area, density, hydronephrosis grade, ureteral location, and ureteral wall thickness at the thickest adjacent soft tissue point on the non-contrast CT scan were assessed by a reviewer blinded to the stone passage. Simple binary logistic regression models were used to assess the correlation between previously established risk factors and spontaneous passage. Furthermore, a multivariate binary logistic regression model was used to validate the univariate relationships.

Longer, wider, and denser stones surrounded by a thicker ureteral wall had a significantly lower likelihood of spontaneous stone passage on univariate analysis. However, in the multivariate analysis, only the largest stone linear dimension retained its significance. In conclusion, in a well-powered prospective study, ureteral wall thickness was not found to be a significant predictive factor for spontaneous stone passage when adjusted for stone size. Indeed, the largest stone's dimension was found to be the only significant predictive factor for spontaneous stone passage. Thank you.