Catheters for hemodialysis, often referred to by the generic term Perm-cath, are typically double barrel plastic tubes inserted into one of the large veins of the body to allow for the removal and reinfusion of large volumes of blood. Peritoneal dialysis catheters are typically single barrel and are placed through the wall of the abdomen into the abdominal cavity. Catheters have the advantage of being  available for use upon insertion and aside from the discomfort of insertion, are associated with minimal discomfort during dialysis. The downside is that it leaves the patient with an externally protruding catheter, makes bathing difficult, and are prone to infection and clotting. These are placed by vascular surgeons, interventional radiologists, general surgeons, and some nephrologists.