Incidence and Timing of Venous Thromboembolism After Implantable Port Placement in Cancer Patients: A Single-Centre Cohort Study

BackgroundImplantable venous access devices are widely used in oncology but introduce an additional risk of venous thromboembolism (VTE). Data on the incidence and temporal distribution of thrombotic events after port implantation remain limited and heterogeneous. This study aimed to evaluate the incidence and timing of VTE following implantable port placement in cancer patients.MethodsThis single-centre cohort study included consecutive adult oncology patients undergoing totally implantable venous access device placement between February 2024 and August 2024. Early catheter-related thrombosis (CRT) was assessed using ultrasound 10-12 days after implantation. Outcomes were obtained through chart review until February 2026. The primary endpoint was first objectively confirmed VTE event. Cumulative incidence functions accounting for death as a competing risk were used for time-to-event analyses.ResultsA total of 131 patients were included in survival analysis. Early CRT was detected in 2.29% of patients. During a median follow-up of 534 days, nine VTE events occurred (6.87%), corresponding to an incidence rate of 0.166 per 1,000 catheter-days. Six patients (4.58%) died during follow-up. The cumulative incidence of late VTE accounting for death as a competing risk was 3.26% at 90 days, 5.94% at 180 days and 8.05% at 365 days. No predictors of late VTE were identified in exploratory analyses.ConclusionsVTE following implantable port placement occurs with a modest cumulative incidence and was concentrated within the first six months after implantation. Early asymptomatic CRT was uncommon. These findings highlight a period of increased thrombotic vulnerability during early port use.