"Congestive Nephropathy" Due to Thrombus in Superior Vena Cava After Kidney Transplantation

Introduction: Congestive nephropathy(CN) is a potentially reversible but underappreciated pathophysiology of renal dysfunction associated with declining renal venous outflow and progressively increasing renal interstitial pressure(Fig:1).Catheters in central veins for haemodialysis,even if inserted in remote past,can be one of the causes of CN after kidney transplantation. Case Description: Thrombus in SVC just below the azygous vein due to haemodialysis catheter inserted three years ago,led to the development of SVC syndrome just after kidney transplant surgery.Renal functions deteriorated with fluid resuscitation due to development of congestion in renal vein which improved with decongestion therapies [diuretics,haemodialysis and endovascular intervention and stenting(Fig:2)].Renal biopsy was characterized by markedly dilated veins and peritubular capillaries on a background of almost normal glomeruli and tubular cell differentiation.High resistive index of renal and interlobar arteries with absent end diastolic flow was found in doppler study which improved after decongestive therapies. Discussion: Decreased renal perfusion has traditionally been implicated to cause renal dysfunction in cardiorenal syndromes.This case highlights that congestion is also a major determinant,the diagnosis of which may be challenging as there is no gold standard to assess renal venous congestion.Improvement of renal function by decongestion is an important clue to this haemodynamic phenotype.Identification of underlying pathophysiology will guide appropriate management strategies.Pathophysiology