The result of a kidney transplantation may be affected by certain congenital or acquired urological diseases that need to be addressed before, during or after the kidney transplant. Complications accompanying kidney transplantation are not fundamentally different from the events that accompany other diffi cult surgical procedures. However, their course is usually modifi ed by adverse circumstances in the recipient -uremia, dialysis treatment, immunosuppression. The incidence of urological complications is reported in the range of 1 to 30 % of the transplants, and they represent up to one half of all surgical complications. They can cause a signifi cant morbidity and mortality and can lead to a delayed onset of the function and even to a loss of the transplanted kidney. Urological complications that need to be addressed before kidney transplantation include anomalies or pathological changes in the lower urinary tract, pelvic involvement in atherosclerosis or previous kidney transplants, infectious foci in lithiasis or pyonephrosis, large polycystic kidneys and malignancies. During the kidney transplantation itself, vascular complications, and complications connected with the reconstruction of the lower urinary tract can occur. Other complications are bacterial and viral infections and malignancies. All these complications require a rapid and accurate diagnosis and subsequent targeted treatment with intention to maintain a functional kidney transplant (Fig. 11, Ref. 36).

Recurrence of the primary disease is one of the most common causes of graft failure in the fi rst decade after kidney transplantation. We present a case of a patient with an unusually rapid recurrence of focal segmental glomerulonephritis in the graft, the recognition of its occurrence was hampered by the primary graft affection and oligoanuria and by insignifi cant histological changes in the fi rst two biopsy samples in the early posttransplant period, as well as by unawareness of the disease leading to terminal renal failure, as no renal biopsy was performed due to grade 3 obesity. Only worsening of hypoalbuminemia and fi nding of massive proteinuria despite oligoanuria were crucial for further management. Disease recurrence in the graft was confi rmed by electron microscopy. However, complex targeted therapy did not result in restoration of graft function and decrease in proteinuria. This case history was aimed to draw attention to the knowledge of the importance of the primary disease confi rmed by renal biopsy and early (so called pre-emptive) treatment in case of diseases with a high potential of recurrence (Fig. 7, Ref. 10).