Catheter occlusion by calcium carbonate during simultaneous infusion of 5-FU and calcium folinate.

BACKGROUND: The treatment of colorectal cancer with administration of a 2-h infusion of calcium folinate followed by a 24-h infusion of 5-fluorouracil (5-FU) is a standard therapy. Based on newly published data we have applied an infusion of both compounds, 5-FU and calcium folinate, mixed together in an ambulatory pump.

PATIENT AND METHODS: We report on a patient suffering from metastatic rectal cancer. After first and second line chemotherapy we started third line chemotherapy consisting of calcium folinate (1,000 mg) and 5-FU (4,000 mg) mixed together in a total volume of 240 ml in an ambulatory pump and administered over a period of 24 h. After a total of 11 applications the patient developed a port thrombosis resistant to lysis with urokinase. The blocked catheter was surgically explanted and the firm material inside was analyzed.

RESULTS: The material from inside the lumen of the catheter was analyzed using x-ray spectroscopy and a scanning electron microscopy. Both analyses confirmed that the isolated material is calcium carbonate.

CONCLUSION: This case and the results of the analyses are in accordance with the described problems and results published earlier. A physical and/or chemical in vitro compatibility of 5-FU and calcium folinic acid, without validated clinical data is not sufficient to use this mixture in routine clinical practice.