Changing picture of renal cortical necrosis in acute kidney injury in developing country

Abstract

Renal cortical necrosis (RCN) is characterized by patchy or diffuse ischemic destruction of all the elements of renal cortex resulting from significantly diminished renal arterial perfusion due to vascular spasm and microvascular injury. In addition, direct endothelial injury particularly in setting of sepsis, eclampsia, haemolytic uremic syndrome (HUS) and snake bite may lead to endovascular thrombosis with subsequent renal ischemia. Progression to end stage renal disease is a rule in diffuse cortical necrosis. It is a rare cause of acute kidney injury (AKI) in developed countries with frequency of 1.9%-2% of all patients with AKI. In contrast, RCN incidence is higher in developing countries ranging between 6%-7% of all causes of AKI. Obstetric complications (septic abortion, puerperal sepsis, abruptio placentae, postpartum haemorrhage and eclampsia) are the main (60%-70%) causes of RCN in developing countries. The remaining 30%-40% cases of RCN are caused by non-obstetrical causes, mostly due to sepsis and HUS. The incidence of RCN ranges from 10% to 30% of all cases of obstetric AKI compared with only 5% in non-gravid patients. In the developed countries, RCN accounts for 2% of all cases of AKI in adults and more than 20% of AKI during the third trimester of pregnancy. The reported incidence of RCN in obstetrical AKI varies between 18%-42.8% in different Indian studies. However, the overall incidence of RCN in pregnancy related AKI has decreased from 20%-30% to 5% in the past two decades in India. Currently RCN accounts for 3% of all causes of AKI. The incidence of RCN in obstetrical AKI was 1.44% in our recent study. HUS is most common cause of RCN in non-obstetrical group, while puerperal sepsis is leading cause of RCN in obstetric group. Because of the catastrophic sequelae of RCN, its prevention and aggressive management should always be important for the better renal outcome and prognosis of the patients.

Keywords: Acute kidney injury, Hemolytic uremic syndrome, Renal cortical necrosis, Postpartum hemorrhage, Septic abortion, Puerperal sepsis, Eclampsia

Core tip: Acute kidney injury (AKI) due to renal cortical necrosis (RCN) is rare in developed countries with reported incidence of less than 2% of all cases of acute renal failure. In contrast, its incidence is higher in developing countries ranging between 6%-7% of all causes of acute renal failure (ARF). Pregnancy related complications are the most common cause of RCN. With improved health care, wider availability of dialysis, and marked decline in septic abortion, the incidence and severity of RCN has decreased in developing countries in recent years. RCN accounts for 3% of all causes of AKI in our recent study. The current incidence of RCN in obstetrical AKI was 1.44% in 2003-2014. The most common cause of RCN is haemolytic uremic syndrome among non-obstetric patients and puerperal sepsis is the leading cause of RCN in pregnant patients. The strategy involving prevention and effective management of haemorrhagic and septic complications of pregnancy will further reduce the RCN incidence in pregnant patients in developing countries.