Thrombosis of tunneled-cuffed hemodialysis catheters: treatment with high-dose urokinase lock therapy.

Thrombosis-related malfunction of tunneled-cuffed central venous catheters (TCC) for hemodialysis (HD) currently leads to a high rate of untimely catheter removal. Urokinase (UK) therapy is used for TCC thrombosis/malfunction, but no consensus exists on the adequate dose to obtain thrombolysis. We selected 72 HD patients with TCC and a mean age and HD vintage of 74 years (range 65-87) and 36 months (range 12-61), respectively. All patients received warfarin therapy with a target international normalized ratio (INR) of 1.8-2.5. Coagulative assessment of the patients was obtained by checking the INR, activated partial thromboplastin time, fibrinogen, hemoglobin, and platelets. Sixty-five thrombotic events were recorded during a 3-year follow-up (median 0.3 events/patient/year). The patients selected were randomized into two groups according to a different thrombolytic therapy. Group A comprised 29 thrombotic events in 32 patients who received UK 25,000 IU in both arterial and venous lines of the TCC for each event. UK restored an adequate blood flow rate (BFR) for HD (≥ 250 mL/min) in 4/29 events (13.7%), whereas addition of 50,000 IU to both arterial and venous lines was required in 25/29 events (86.3%). For the same 25 events in the second HD session, a further 75,000 IU of UK was needed for each TCC lumen. Group B comprised 36 thrombotic events in 40 patients who received 100 000 IU of UK in the arterial and venous lumen of the TCC for each event. An adequate BFR was recovered in all events. In 12/36 events (33.3%), 100,000 IU UK for both lumens were needed in the second HD. In conclusion, group B patients obtained (i) a significantly better TCC patency than group A patients; (ii) a low UK administration in the following HD sessions; and (iii) no bleeding complications.

Development of a Nephrotic Syndrome in a Patient with Gastrointestinal Stromal Tumor during a Long-Time Treatment with Sunitinib.

A patient with advanced gastrointestinal stromal tumor (GIST) receiving second-line treatment with sunitinib developed edema, increase of the serum creatinine, weight gain, nephrotic syndrome with proteinuria of 12 g/24 h, dyslipidemia, hypoalbuminemia and also presented with hypertension. A kidney biopsy showed an immunocomplex glomerulonephritis. Steroid treatment was started, but the clinical conditions and laboratory values did not improve. So in the hypothesis that the nephrotic syndrome was induced by sunitinib, sunitinib was temporarily discontinued with a subsequent reduction of proteinuria and improvement in blood pressure control. In the last years, the introduction of sunitinib has modified the natural history of advanced GIST. However, due to chronic and prolonged intake of this drug, there is increasingly frequent detection of late and unknown toxicities in clinical practice. In particular, the late renal toxicity from sunitinib may be the primary clinical problem with this drug in the case of prolonged treatment. Monitoring of kidney function and blood pressure should be performed for early detection of side effects such as hypertension and kidney dysfunction in advanced GIST patients receiving long-term treatment with sunitinib. A clinical collaboration between oncologists and nephrologists could be useful with the objective to optimize the management of sunitinib.