A Retrospective Chart Review to Assess Indications, Risk Factors and Complications Associated with the Use of Indwelling Catheters in Pediatric Patients with Sickle Cell Disease - a Single Institution Experience

Background: Sickle cell disease (SCD) and its complications are associated with frequent hospital visits and treatment often requires venous access for administration of fluids, medications and blood transfusions. Due to frequent use, peripheral venous access can become difficult over time because of venous scarring. Moreover, certain interventions such as chronic simple or exchange transfusions require reliable venous access for prolonged periods of time. Implantable central venous devices such as ports offer definitive access and mitigate the need for frequent peripheral access attempts. However, existing knowledge on the use of these devices in pediatric patients with SCD is limited. Due to possible increased risks of thrombosis and mechanical occlusion from hypercoagulable state, risk of infectious complications and need for surgical placement, ports are often not used routinely. We review the indications and complications associated with placement of ports in the pediatric cohort of patients with SCD - to better define the scope of port placement in this group.

Methods: We performed an IRB-approved, retrospective chart review to assess the indications, complications and risk factors associated with port placement in children and adolescents with SCD at the University of Oklahoma Health Sciences Center (OUHSC). The study period analyzed was 17.5 years from January 1^st, 2000 to July 30^th, 2018 and included patients from birth to 21 years of age, diagnosed with SCD who had homozygous sickle cell disease (HbSS) or compound heterozygous SCD - either sickle cell-β⁰-thalassemia, sickle cell-β⁺-thalassemia or sickle cell-hemoglobin C (HbSC) disease, and had ports in place for more than 7 days. Patients were identified systematically by querying the OUHSC Clinical Data Warehouse using diagnostic codes followed by chart review.

Results: Thirty-two patients with SCD and ports were identified during the study period, out of which 31 patients had HbSS and one patient had HbSC disease. The median age at first port insertion was 8 years (range 1-20 years). A total of 63 ports were placed for a total of 99,272 port days with a median port life span of 1340 days. The two main indications for port placement were - either chronic transfusions for which 48 ports were placed for a total of 80,238 port days, or poor venous access (PVA) for which 15 ports were placed for a total of 19,034 port days. Out of the 48 ports placed for chronic transfusions, 6 ports were for transfusions for primary stroke prophylaxis, 22 ports were for transfusions for secondary stroke prophylaxis, 17 ports were for transfusions for recurrent vaso-occlusive episodes (VOE) and 3 ports were for transfusions after multi-organ failure.

A total of 54 port complications occurred (malfunction=29, infection=20, thrombosis=3, difficult port access=1, and intractable pain over port site=1). From the data available, more ports were placed in the left subclavian vein (LSV=20) than right subclavian vein (RSV=4) and right internal jugular (RIJ=2), however rate of overall complications were similar between LSV and RSV - 0.57 complications/1,000 catheter days in LSV and 0.58 complications/1,000 catheter days in RSV. The rate of port associated infection, defined as a positive blood culture drawn from the port, was 0.2 per 1,000 port days. A total of 20 infections identified mostly gram-positive organisms (n=15) predominantly Staphylococcus, compared to gram-negatives (n=3), fungus with Candida albicans (n=1) and a rare acid-fast bacilli infection with Mycobacterium mucogenicum (n=1). The rate of thrombosis, identified radiologically using vascular doppler ultrasound, was 0.03 per 1,000 port days. The rate of premature port removal arising from complications was 0.36 per 1,000 port days. Ports placed for chronic transfusions had a lower rate of removal (0.31 per 1,000 port days) compared to ports placed for poor venous access (0.58 per 1,000 port days) with a ratio of 0.54 which approached statistical significance (p=0.09; CI 0.26-1.21).

Conclusion: Ports in pediatric patients with SCD are associated with low rates of thrombosis, infection and malfunction. Ports may be a reasonable alternative for vascular access in patients with SCD - especially in patients who require chronic simple or exchange transfusions and have difficult access. Larger prospective studies will be needed to further assess the scope of use of ports in this population.