Validation of the Japanese Association for the Surgery of Trauma Type 3 Subclassification of Renal Trauma Using the...

The Japanese Association for the Surgery of Trauma (JAST) renal trauma classification is widely used in Japan but has not been validated using nationwide multicenter data. This study aimed to assess its clinical validity in blunt renal trauma.

We conducted a retrospective cohort study using 2019-2024 data from the Japan Trauma Data Bank (JTDB), a nationwide multicenter trauma registry. Among 1256 renal trauma patients in the JTDB, we included those with isolated JAST Type 3 blunt renal trauma (severe parenchymal renal trauma) and classified them as Type 3a or 3b. Multivariable logistic regression was used to identify factors associated with operative management (OM).

Among 219 patients (Type 3a trauma, n = 136; Type 3b trauma, n = 83), OM was more frequent in Type 3b (14.5% vs. 2.9%, p = 0.002). In multivariable analysis, shock on arrival (odds ratio [OR], 7.96; 95% confidence interval [CI], 2.11-30.08; p = 0.002) and Type 3b trauma (OR, 4.49; 95% CI, 1.35-14.96; p = 0.023) were independently associated with OM.

This nationwide multicenter cohort study demonstrated that JAST Type 3b trauma was independently associated with OM in patients with blunt renal trauma. The JAST Type 3 subclassification provides clinically relevant information for predicting the need for OM.