Prosthetic arteriovenous grafts for hemodialysis.
BACKGROUND
Prosthetic arteriovenous (AV) grafts are indicated in patients with failed AV fistula (AVF), exhausted superficial veins or unsuitable vessels. Increasing the proportion of prevalent hemodialysis (HD) patients using autogenous AVF should reduce the need for AV grafts and associated morbidity. This paper reviews the current role of prosthetic AV grafts in vascular access for HD.


METHODS
Prior to the insertion of a prosthetic AV graft, a comprehensive review of previous access procedures and full physical examination in addition to vessel mapping is required. Anastomotic technique should take into account the flow diffuser concept, graft geometry and an anastomotic angle of 15 degrees in order to reduce the incidence of intimal hyperplasia.


RESULTS
Many authors report 1 and 2-yr cumulative graft patency rates of 59-90% and 50-82%, respectively. The major drawbacks with synthetic grafts include: thrombosis, a five-fold increase in infection risk and steal syndrome. The choice between surgical and percutaneous methods of dealing with blocked AV grafts remains controversial, though percutaneous techniques are assuming an increasingly important role. Percutaneous strategies are successful in declotting access in 67-95% of cases. Stenting of stenotic lesions following thrombectomy improves secondary patency rates. Strategies for dealing with AV graft infection include antibiotic prophylaxis, partial, subtotal or total graft excision and the use of biological prosthesis.


CONCLUSIONS
Though more prone to complications than autogenous AVFs, AV grafts offer a short maturation period and are more amenable to thrombectomy by radiological or surgical means. Complex AV grafts may be appropriate in patients with exhausted access sites.
Akoh
Jacob A
JA
Surgery & Renal Services Directorate, Plymouth Hospitals NHS Trust, Derriford Hospital, Level 04, Plymouth PL6 8DH, UK. Jacob.akoh@phnt.swest.nhs.uk
D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects / Q000295:instrumentation*; D001807:Blood Vessel Prosthesis / Q000009:adverse effects; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D003251:Constriction, Pathologic; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000503:physiopathology; D006801:Humans; D007511:Ischemia / Q000209:etiology; D018579:Patient Selection; D011474:Prosthesis Design; D016459:Prosthesis-Related Infections / Q000209:etiology; D006435:Renal Dialysis; D018570:Risk Assessment; D013927:Thrombosis / Q000209:etiology / Q000503:physiopathology; D013997:Time Factors; D016896:Treatment Outcome; D014654:Vascular Patency