Giant pyohydronephrosis in a febrile haemodialysis patient

Abstract

A 73-year-old man had been receiving regular haemodialysis initially via arteriovenous fistula for 3 years and had been using a cuffed dual-lumen permanent catheter (HemoStarTM, BardTM, US) for the preceding year due to vascular access failure. He was referred to our hospital owing to an intermittent fever up to 38°C throughout the preceding month. Repeated blood cultures were positive for methicillin-resistant Staphylococcus aureus (MRSA). Fever was persistent despite intravenous administration of teicoplanin for 2 weeks. Upon admission, the HemoStarTM was immediately removed and vancomycin was intravenously administered since catheter-related infection was suspected. However, the fever still persisted, and blood cultures and the tip of HemoStarTM were negative for bacteria. Echocardiography showed no evidence of vegetation. By further survey of possible infection, computed tomography of the abdomen revealed a giant left hydronephrosis and hydroureter with thinning of the renal parenchyma (Figure 1a) due to obstruction by a ureteral stone at the fourth lumbar level (Figure 1b). We placed a pig-tailed catheter in the left renal pelvis and drained out 1400 ml of pus-like material, which displayed a positive culture forMRSA. Following adequate pus drainage and antibiotic treatment, his fever subsided dramatically. Tracing back his history, he had stones in the left kidney, which were treated with extracorporeal shock-wave lithotripsy several times. ‘Giant hydronephrosis’ is a rare condition defined by the presence of 1000 ml or more fluid in the collecting system of kidney [1]. The ureteropelvic junction is the most common site for developing giant hydronephrosis [2]. Stones, congenital ureteral narrowing and ureteropelvic tumours are the major causes [2]. Fever was the initial symptom in the present case; however, the definite diagnosis was made 2 months later. This is typical for this type of occult condition. Unless the physician has a high level of suspicion, recognition of giant hydronephrosis may be delayed and further impeded in the presence of end-stage renal failure. To prevent the infectious complications of giant hydronephrosis, it is mandatory to make an early diagnosis whenever possible. In a febrile haemodialysis patient who was refractory to antibiotic treatment, clinical suspicion of pyohydronephrosis should be aroused, especially in a subject having renal stone history.