Safety of 3-month flushing interval for prevention of occlusion in totally implantable venous access ports: An analysis focused on intraluminal clots

Background: This study aimed to assess the safety and feasibility of a 3-month flushing interval for totally implantable venous access ports (TIVAPs), particularly regarding intraluminal clot formation. Methods: Between May 2017 and September 2018, we established a single-center cohort of 151 patients who were referred for TIVAP removal and categorized them into three flushing-interval groups: A (<= 1 month), B (1-2 months), and C (2-3 months). Odds ratios (OR) with 95% confidence intervals (CI) were computed using logistic regression to determine the risk of intraluminal clot occurrence. To compare clot lengths among the groups, we employed linear regression. Restricted cubic splines were used to model the flushing interval as a continuous variable. Results: Compared to Group A, Groups B and C had adjusted ORs of 0.82 (0.35-1.92) and 0.78 (0.29-2.11) for intraluminal clot risk. Occlusion was rare (1/151; 0.7%) and successfully treated with mechanical recanalization. Adjusted differences in clot length compared to Group A were 0.01 (-0.85 to 0.87) for Group B and -0.23 (-1.21 to 0.76) for Group C. Spline regression analysis showed no significant association between the flushing interval and clot length (p for trend = 0.84). Conclusion: The incidence and burden of intraluminal clots did not increase significantly within the first 3 months. Occlusion was rare, even in the presence of clots, and was successfully treated. Therefore, a 3-month flushing interval appears to be a safe and practical option, aligning with the common recommendation for surveillance intervals in patients with cancer.