 The procedure requested , for an investigation into the hemodynamic changes in a patient with chronic venous insufficiency ( CVI ) , which results in chronic venous disease , is quite different from an examination request made for suspected deep vein thrombosis . For a DVT investigation there is a need for guidance as to what to look for and to the intended treatment . An investigation performed with the intention of treating the patient by vein stripping or laser therapy for example is very different from the examination performed with the intention of executing a CHIVA . This French originated procedure is also spelt out as conservative hemodynamic treatment for chronic venous insufficiency . A CHIVA is an ultrasound guided , minimally invasive surgery strategic for the treatment of varicose veins , performed under local anaesthetic . 
