Prolonged antibiotic treatment for infected low flow vascular malformations.

BACKGROUND: Infection in low flow malformations is difficult to diagnose and treat. Initial presentation can be followed by cycles of recurrent infection lasting several years. The optimal duration of antibiotic therapy to prevent recurrence of infection has not been established.

METHODS: All cases of infection in low flow malformations at the Royal Children's Hospital over a ten-year period were reviewed. Clinical markers of infection and duration of initial antibiotic treatment were correlated with the development of recurrent episodes of infection.

RESULTS: Twenty-one patients met criteria for inclusion. Nineteen were diagnosed as lymphatic malformations and two as venous malformations. The majority of patients (13 or 62%) received a prolonged course of six weeks or more of antibiotics. Eleven (52%) patients went on to have recurrent infections, but these were significantly less likely to be in those treated with a long course of antibiotics (Fisher's exact test, p=0.026). In only 12 of 21 cases could a bacterium be grown. Elevated CRP was the most consistent abnormal laboratory finding in infection.

CONCLUSIONS: Longer courses of antibiotics reduce the risk of recurrent infection in low-flow vascular malformations. We recommend an antibiotic course of three months or more at the initial presentation of infection in a low flow malformation. Elevated CRP is the most sensitive test for diagnosis of infection in low-flow malformations.

TYPE OF STUDY: Treatment study.

LEVEL OF EVIDENCE: III.