Résumé
Renal cortical necrosis (RCN) is a rare and severe disorder resulting from prolonged hypoperfusion, often secondary to shock, and usually associated with hemostasis disorders. Current knowledge of this disease is limited to a few studies, mostly single-center, from low-income countries such as India. Prevalence in France is estimated at 2% of AKI. We lack recent, representative data on epidemiology, etiologies, renal evolution, mortality and risk factors for renal evolution. Imaging has supplanted histology as the reference diagnostic strategy, and injected CT-scan is considered as the most sensitive. Moreover, imaging at diagnosis would appear to be predictive of renal evolution, differentiating between diffuse and patchy cortical necrosis. We conducted a nationwide, multicenter retrospective study including 134 cases of RCN in native kidneys, all radiologically and/or histologically proven. The inclusion period was from 01/01/2010 to 31/12/2023 and 21 French centers participated. We separated the cohort into obstetrical and non-obstetrical group. Descriptive statistics, uni- and multivariate survival analyses were performed. RCN mainly affects young women with approximately half the cases occurring in obstetrical settings. Non-obstetrical cases also affected more women with younger ages than affected men. The two main etiologies were hemorrhagic and septic shock. Thromboembolic and drug-induced causes were also found, with a predominance of CAPS and exacyl respectively. Isolated thrombotic microangiopathy (TMA) was also an etiological group and in a large number of cases, the etiology was mixed. On management, almost all patients were anuric, requiring dialysis, and about half were weaned off it with a median delay of one month. Most recovery of function occurred within the first 3 to 6 months post-weaning. Whatever the GFR recovered at 3-6 months, it remained stable over the 2-year follow-up period. Presenting a severity factor at the time of management, such as cardiorespiratory arrest, multivisceral failure syndrome or recourse to ECMO, emerged as a risk factor for non-recovery of renal function. Diffuse cortical damage on initial imaging was also identified as a risk factor. Finally, weaning time < 40 days was associated with better functional recovery at 12 months. Despite being the most severe form of existing AKI, RCN has a significant capacity for recovery that is maintained over time. The role of estrogenic hormones in the pathophysiology is postulated, given the observed sex ratio, the young age of the women and the importance of the obstetrical context. Imaging appears to be useful in predicting the risk of remaining on dialysis, although if performed too early, it may tend to overestimate the true extent of necrotic areas. Repeating the examination at a distance from the event could be helpful for observing the evolution of non-perfused areas and better predicting renal recovery.