Fistula Occlusion – Prevention and Treatment
While there is no doubt that AV fistulas are the golden standard of vascular access forms and should be the preferred choice whenever possible, they are not without complications. Recent studies show that up to 85% of patients will require medical or surgical interventions.
Vascular occlusion and other causes of fistula failure
Fistula failure is most often a result of a progressive narrowing of the anastomosis, the connection point between the vein and the artery, due to intimal hyperplasia or repeated punctures in the vein.
Vascular occlusion refers to blockage of blood vessels, usually by a clot. Vascular occlusion is one of the most common complications, causing deep vein thrombosis and resulting in severe pain, tremors, loss of feeling and fatalities due to ischemic heart disease or stroke.
Symptoms of stenosis, thrombosis and occlusion include reduction in dialysis quality, prolonged bleeding and pain.
Preventing fistula occlusion
While prevention is not always possible, there are several things that can be done in order to reduce the risk of occlusion, thrombosis and stenosis.
Prior to surgery – Patient should discuss use of VasQ, with physician. VasQ is a device, implanted during the fistula creation procedure, designed to improve maturation and patency rates of AV fistulas by providing external support and regulating blood flow while reinforcing the perianastomic vein. The potential result of using VasQ is a reduced rate of complications and an improved fistula outcome.
Post-surgery – it is important that patient optimize fistula maturation by doing daily hand exercise, and adhere to strict hygiene and cleanliness instructions. Also, patient should avoid wearing restrictive clothing or jewelry, carrying heavy weights with fistula arm, use of bag straps around arm, and should make sure that no pressure is placed on fistula.
Monitoring of fistula
Early identification is critical in allowing for early treatment, before life threatening complications occur. Daily self-monitoring of fistula is vital and a weekly examination of fistula by physician or nurse is recommended, during which fistula should be checked for thrill and bruit, inflow and outflow stenosis and edema.
Treatment of fistula occlusion
When occlusion symptoms occur it is generally necessary to undergo a procedure in order to unclog the blood vessel. In the past, surgical thrombectomies were required, resulting in exhaustion of veins and the need to create a new vascular access for hemodialysis. In recent years, minimally invasive procedures have come into use, prolonging the life span of vascular access.
Procedures are generally done on an outpatient basis under local anesthesia and include: Angioplasty and Vascular Stenting (use of a balloon tipped catheter to unblock the site or placement of a stent to hold open the vessel), Catheter Directed Thrombectomy (dissolving of clot via medication or by use of a mechanical device) and others. These procedures may cause some discomfort and rest is recommended for the 24 hours after the procedure. If blockage is too severe surgery may be needed. In that case a temporary catheter may be placed in order to allow for continuing of dialysis.