Introduction: Catheter related thrombosis (CRT) is a severe and potentially life threatening long-term complication in intestinal failure (IF) but the optimal preventive therapy for CRT is unknown. This study assessed the efficacy and safety of two protocols of secondary anticoagulation (AC) prophylaxis with low molecular weight heparin (LMWH).

Methods: This is a multicenter (N=2), retrospective cohort study of children on home parenteral nutrition (HPN) with a previous episode of CRT. Secondary AC, based on center’s protocol, was initiated once a first CRT was identified. In the short-term protocol (N=10) patients received therapeutic dosing until thrombus resolution or up to 4 months and in the long-term protocol (N=26) prophylactic dosing continued until line removal. All patients underwent routine vascular US at 12m after initiation of AC. The primary outcome was CRT recurrence or progression of CRT at 12 months post therapy.

Results: Patient demographics were similar between groups. Median age at first CRT was 7 months (IQR 2.8-16.5) and median time since PN initiation was 4.5 months (IQR 1.9-15.4). CRT frequency was similar between PICC line and tunneled central venous catheter (23% vs 28% respectively, p=0.48) and between insertion sides (27% right vs 21% left, p=0.45). Progression/recurrence of CRT within 12 months of initiation of AC occurred in 7 (70%) patients in the short-term group and 2 (8%) in the long-term group (p=0.0001) in a median of 61 days (IQR 35-173). Total CRT recurrence/progression for the long-term protocol group was 9/26 (35%) patients at a median follow up of 19.5 months (IQR 16.2-34.3). Patients with recurrence of CRT had a greater number of catheters/1000 catheter days (23.5 vs 5.5, p=0.014). The presence of symptoms or complete vessel occlusion at the first CRT episode and frequency of CLABSI between CRT episodes were not associated with an increased risk of recurrence. One patient had a mild allergic reaction, one discontinued treatment following GI bleeding and two at the family and patient’s request. Medication adherence was good (>80% of doses) in all patients in the short-term and 89% of patients in the long-term group.

Conclusions: Long-term secondary anticoagulation prophylaxis with LMWH is more effective than short-term therapeutic AC for the prevention of recurrence or progression of CRT at 12 months. Secondary AC prophylaxis should be considered in children with CRT to maintain long-term venous patency while on PN.