Right atrial thrombi in children with cancer and indwelling catheters.

OBJECTIVE

To determine the prevalence of right atrial thrombi in children with cancer and indwelling catheters.

STUDY DESIGN

We systematically examined 156 children with cancer and indwelling catheters for the presence of a right atrial thrombus when they underwent routine screening of cardiac function by two-dimensional echocardiography.

RESULTS

Thirteen children (8.8%) had right atrial thrombi. Of the 13 children, 6 had thrombi adherent to the right atrial wall, and in 5 of these 6 children the clots were considered large enough to require intervention: 2 children with obstruction of venous or tricuspid valve inflow underwent right atriotomy and thrombus removal; they recovered and remained well. The other 3 children had moderate-sized thrombi and were treated with oral anticoagulants; their clots stabilized (2 children) or regressed (1 child). The remaining 7 children had thrombus on the tip of the catheter: 5 of these children were observed; the thrombi spontaneously resolved in 2 of them and did not change in size in the other 3. In the sixth child, the catheter malfunctioned 2 weeks after discovery of the clot and the catheter was removed. The seventh child was treated with warfarin and the clot decreased in size. Thrombi were detected in a greater proportion of children with catheter tips in the right atrium versus the superior vena cava, and in a greater proportion of children with acute lymphoblastic leukemia versus other diagnoses. There was no association between the presence of a clot and duration of time the catheter was in place, the number of catheters placed, treatment with asparaginase, or treatment with total parenteral nutrition.

CONCLUSION

The incidence of right atrial thrombi in children with indwelling catheters may be higher than was previously appreciated.