Introduction: Among genitourinary traumas, blunt trauma to the kidney (BTK) is the most common: their initial management has been well studied, but their long-term future is poorly documented. The main objective of this study was to assess the frequency of late complications after BTK, the secondary objective was to identify their predictors of occurrence.
Methods: A retrospective observational study of the TraumAFUF project was conducted, including, between 2005 and 2018, all BTK treated in 18 French hospitals and followed for more than 3 months. The characteristics of the initial trauma, as well as any complications occurring after three months, were identified. The patients were divided into two groups: onset of a late complication (LC group) or uncomplicated (NLC group). The groups were compared in univariate and multivariate analyses to identify the risk factors for the occurrence of these complications.
Results: Among the 454 patients included, the median and mean duration of follow-up were 14.8 and 27 months (SD=31 months). Fifty presented with LC (11%), the most frequent being a symptomatic morphologically altered kidney (2.9%), a secondarily impaired biological renal function (2.9%), or a secondary arterial hypertension (2.4%). The median time to complication was 12±3 months. In univariate analysis, the risk factors identified were: high grade renal trauma = IV (OR=2.4, p=0.025), active bleeding (OR=2.6, p=0.007), need for transfusion (OR=2.3, p=0.001), or interventional or endoscopic treatment (OR=1.7, p=0.09 and OR=2.0, p=0.035). However, in multivariate analysis, none of these items appeared to be an independent risk factor for late complication.
Conclusions: BTK occurs particularly in young patients and is associated with immediate morbidity, but also long-term morbidity, as late complications can occur more than 3 months after the trauma in 11% of cases. In our study, certain risk factors for these complications seem to emerge: high grade of the AAST classification, active bleeding, initial transfusion or interventional management. If we were unable to identify an independent risk factor for late complication after BTK, however, it allows us to identify a patient profile that could require prolonged follow-up, in order to detect these complications and prevent their progression.