A medical blood access system used for hemodialysis treatment to enable blood withdrawal for processing of blood by an external apparatus and return the same blood to a patient, comprising an interfacial fluid conduit between the machine and patient's blood supply which is repeatedly connectable along a guided pathway passing through epidermis and subcutaneous tissue via a naturally formed tissue tract to enter blood space, providing improved patient safely, convenience, effective prophylaxis, without bleeding or tissue trauma or pain, and is executable by the patient to precisely connect and disconnect with minimal disfigurement or life restrictions, and is useable on virtually all patients soon after placement and is robust and safe to high blood flow.