Evidence on port-locking with heparin versus saline in patients with cancer not receiving chemotherapy: A randomized clinical trial

Objective: To assess the safety and efficacy of port-locking with heparin every 2 months vs. every 4 months and vs. saline solution every 2 months in patients with cancer not receiving active chemotherapy. The hypothesis stated that locking with heparin at four-month intervals and saline at two-month intervals would not increment > 10% of port obstructions. Methods: Multicentre, phase IV parallel, post-test control group study took place at the two chemotherapy units of oncology hospitals. Included patients with cancer with ports that completed the chemotherapy treatment but still having port maintenance care or blood samples taken up to four months. A sample of 126 patients with cancer in three arms was needed to detect a maximum difference of 10% for bioequivalence on the locking methods. Consecutive cases non-probabilistic sampling and randomized to one of the three groups; group A: received heparin 60 IU/mL every two months (control) vs. group B heparin every four months and vs. saline every two months in group C. Primary variables were the type of locking regimen, port obstruction, and absence of blood return, port-related infection, or venous thrombosis during the study period. Clinical and sociodemographic variables were also collected. Results: A total of 143 patients were randomly assigned; group A, 47 patients with heparin every 2 months, group B, 51 patients with heparin 4 months, and group C, 45 patients with saline every 2 months. All participants presented an adequate blood return and no obstructions, until the month of the 10th, when one participant in the group A receiving was withdrawn due to an absence of blood flow ( P 1/4 0.587). Conclusions: Port locks with heparin every 4 months or saline every 2 months did not show differences in safety maintenance, infection, or thrombosis compared to heparin every 2 months.