Bilateral renal cortical necrosis. A patient followed up over eight years

Acute renal cortical necrosis in pregnancy: Clinical course and changing prognosis

Obstetric cortical renal necrosis is a serious complication that can lead to chronic renal failure and the need for chronic dialysis. The aim of renal cortical necrosis therapy is to restore hemodynamic stability, institute early dialytic therapy, and treat the underlying cause of the disease. Most cases of renal cortical necrosis do not recover a normal renal function despite intensive care. We describe the course of a patient who was diagnosed with acute renal cortical necrosis in pregnancy treated with hemodialysis for three years but then she recovered her renal function.

Purtscher's retinopathy and renal cortical necrosis: two rare vaso-occlusive complications in a patient with acute pancreatitis: a case report

BACKGROUND

Purtscher's retinopathy and renal cortical necrosis are two rare vaso-occlusive complications of acute pancreatitis. Purtscher's retinopathy causes sudden impairment of vision, which was first reported in a patient with head trauma. Subsequently, it was also reported as a complication of acute pancreatitis and few other clinical conditions. Acute pancreatitis also rarely causes renal cortical necrosis leading to acute kidney injury. However, the simultaneous presence of both complications is rarely reported.

CASE PRESENTATION

A 20-year-old Bengali man presented to our hospital with a history of acute upper abdominal pain, vomiting, anuria, and disorientation. He was ultimately found to have bilateral complete blindness due to Purtscher's retinopathy and acute kidney injury due to renal cortical necrosis, as sequelae of acute pancreatitis. He became dialysis-dependent, his vision did not recover, and he died 16 months after diagnosis.

CONCLUSIONS

This case highlights Purtscher's retinopathy and renal cortical necrosis might be considered as a recognized pair complication of acute pancreatitis.

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

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.

Spectrum of renal cortical necrosis in acute renal failure in eastern India

Renal cortical necrosis is an uncommon cause of acute renal failure. We report 23 cases of biopsy-proven renal cortical necrosis which constituted 6.3% (23/363) of all cases of acute renal failure studied over a period of seven years (1985-92). The patients were divided into two groups: obstetric and non-obstetric. Obstetric complications were responsible for renal cortical necrosis in 15 (65.2%) patients while non-obstetric conditions accounted for the remaining eight (34.8%) cases. The overall incidence of cortical necrosis in obstetric acute renal failure was 15/63 (23.8%) patients, the incidence being nearly equal in early (20.5%) and late (29%) pregnancy. Post-abortum renal failure was the sole cause of cortical necrosis in early pregnancy in the obstetric group. Haemolytic uraemic syndrome (three patients) and septicaemia (two patients) were the main cause of necrosis in the non-obstetric group. The cortical necrosis was diffuse and patchy in 17 and six patients, respectively. The disease had a fatal prognosis in 20 (87%) patients; mortality was due to uraemic complications and infections in the majority of patients. The high frequency of post-abortum renal cortical necrosis in our patients is similar to the experience of other Indian workers.

Pathogenesis and significance of nonprimary focal and segmental glomerulosclerosis

Injury of the glomerular microvasculature by nonimmunologic processes is often the underlying mechanism of progressive deterioration of renal function in patients with a variety of renal disorders. The structural hallmark of this injury is focal and segmental glomerulosclerosis, often accompanied by entrapment of hyalin. Although such lesions are quite characteristic for diseases that primarily affect the glomerular podocyte, similar damage occurs in association with functional and structural adaptive changes that develop as a consequence of a significant loss of functioning nephrons or other systemic disorders. Experimental studies have revealed that such functional adaptations include intrarenal vasodilatation that through increases in glomerular capillary pressure and plasma flow leads to a significant compensatory hyperfiltration. This functional state is accompanied by a parallel increase in glomerular volume, attained chiefly by expansion of matrix components and an increase in the number of endothelial and mesangial cells, but not of podocytes. The persistence of the adaptive changes results in endothelial, mesangial, and epithelial cell dysfunction revealed clinically by proteinuria and structurally by the development of microthrombosis, microaneurysms, mesangial expansion, and occlusion of capillaries by hyalin accumulation. Although all these pathologic processes can lead to segmental collapse of the capillary tuft, it is the progressive hyalin deposition in capillaries with defective or detached podocytes that represents the major mechanism in the development of segmental and eventually global glomerulosclerosis. The inability of the highly differentiated podocyte to replicate in response to systemic or locally released trophic factors ultimately results in imperfections of the capillary wall that set the stage for permeability defects amplified and accentuated by greatly augmented hydrodynamic forces. These structural and functional microvascular changes acting in concert not only facilitate the transcapillary convection of macromolecules that results in albuminuria, but can also be anticipated to play a key role in the entrapment and accumulation of larger macromolecules in front of the lamina densa in the form of hyalin material. Continuing damage to the glomerular microvasculature exacerbates the adaptive changes in surviving nephrons, closing a positive-feedback loop that culminates in end-stage renal failure.

Spectrum of acute cortical necrosis in Indian patients

Forty-nine out of 662 patients (7.4%) dialysed for acute renal failure were found to have bilateral renal cortical necrosis. Amongst 6061 autopsies carried out in our centre during the same period, the incidence of cortical necrosis was 0.7%. Obstetric causes were responsible for the renal lesion in 35 (71%) and non-obstetrical causes in 14 patients. In the obstetric group, cortical necrosis was observed in association with spontaneous or induced abortion in 39% and as a complication of late pregnancy in 33%. The non-obstetric causes included snake bite in 26 (12%), acute gastro-enteritis in 5 (10%), haemolytic uremic syndrome in 2 (4%) and G6PD deficiency with intravascular haemolysis in one patient (2%). Thirty-nine (80%) patients were anuric or severely oliguric throughout their illness but a steady rise in urinary output following a protracted phase of oligo-anuria was observed in ten patients. Forty-two (86%) patients died and seven survived. None of the survivors, however, achieved a normal renal function (Ccr 8 ml to 28 ml/min). The diagnosis of renal lesion was confirmed during life in 8 and after death in 41 patients. Morphological lesions were consistent with bilateral diffuse cortical necrosis in 39 (80%) and patchy lesions in 10 patients. Factors responsible for the high incidence of cortical necrosis amongst Indian patients have been high-lighted.

Prolonged oliguria with survival in acute bilateral cortical necrosis

Survival is uncommon in cases of acute bilateral cortical necrosis. Three cases admitted to the renal unit at Newcastle have regained useful renal function after oliguric phases of 38, 46, and 120 days.Prolonged periods of intermittent dialysis are justified in patients in whom a firm diagnosis of acute cortical necrosis is made.