Inherited thrombophilic factors do not increase central venous catheter blockage in children with malignancy.
BACKGROUND
Central venous catheter (CVC) blockage is a common complication in pediatric oncology patients. We investigated whether inherited thrombophilic factors may predispose Chinese children with cancer to CVC blockage.


METHODS
Newly diagnosed patients with CVC inserted were recruited during a 30-month period and prospectively followed until CVC removal, end of treatment or death. Protein C (PC), protein S (PS), anti-thrombin III (AT-III), Factor V Leiden (FVL), prothrombin 20210 variant (p20210), and methylenetetrahydrofolate reductase (MTHFR) polymorphism (C677T), were studied with other acquired factors. The primary endpoint was CVC blockage and symptomatic thromboembolic events (TE) were recorded.


RESULTS
Thirty-six patients were recruited. CVC blockage was found in 3/36 (8.3%) and the incidence was 0.23 per 1,000 catheter-days. Among the 3 with CVC blockage, 2 were heterozygous for MTHFR polymorphism and 1 was heterozygous for PC deficiency. One with ALL developed superior saggital sinus thrombosis while on asparaginase and he was heterozygous for MTHFR polymorphism. One ALL patient with combined heterozygous MTHFR polymorphism, PC and PS deficiency did not develop any CVC blockage during a median follow-up of 3.8 years. AT-III deficiency, FVL and p20210 were not found in all patients.


CONCLUSIONS
Compared to previous studies, our cohort had a much lower incidence of CVC blockage. A different pattern of inherited thrombophilic factors was found with heterozygous MTHFR polymorphism being the most common. We concluded that inherited thrombophilic factors alone were not associated with CVC blockage in our pediatric cancer patient population.
Department of Paediatrics & Adolescent Medicine, The University of Hong Kong, Hong Kong.
Brian Hon-Yin
BH
Chung
Edmond Shiu-Kwan
ES
Ma
Pek-Lan
PL
Khong
Godfrey Chi-Fung
GC
Chan
D000293:Adolescent; D002405:Catheterization, Central Venous; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009369:Neoplasms / Q000378:metabolism / Q000628:therapy*; D019851:Thrombophilia / Q000378:metabolism