Klippel-Trenaunay Syndrome.

Klippel-Trenaunay syndrome or KTS is a complex vascular syndrome associated with overgrowth occurring as a result of somatic mutations in the PIK3CA gene. Patients are diagnosed on the basis of physical findings, sometimes with supportive imaging, of commonly a segmental anomaly with a cutaneous port-wine stain, lymphatic and venous malformations and overgrowth. The severity of the component vascular malformations and the degree of overgrowth varies from patient to patient which demands care given by a multi-professional team with regular follow-up in a specialist clinic. Some patients may present with acute life-threatening problems, often as a result of veno-thromboembolic events (VTEs) especially following surgical and invasive radiological procedures. Awareness of such problems is vital and prophylactic measures to reduce such risks are paramount. The interventional radiologist is vital to the care team as he/she can undertake procedures including endovascular closure of significant venous anomalies which predispose to such VTEs. Although these procedures can be lengthy and complex, they can now provide a minimally invasive means to reduce the risk from life-threatening and sometimes fatal VTEs. The results however from such interventions will require long-term studies which to date are unavailable.