CARE AFTER CRYOPRESERVED ALLOGRAFT PLACEMENT
Cannulation of cryopreserved allografts is possible 10-14 days after placement, and when swelling has subsided so that the course of the arteriovenous graft can be palpated. Aseptic technique during cannulation, including standard precautions for hand washing and glove changes, is recommended to minimize risk of access infection. Cannulation technique should be a hybrid of the techniques for expanded polytetra fluoroethylene arteriovenous graft regarding depth of the access and the texture of an autogenous vein. It is also necessary to rotate cannulation sites in order to avoid pseudoaneurysm formation. A retrospective study using constant cannulation (button hole technique) with cryopreserved femoral veins showed good outcomes related to patency and minimal infection risk.
A qualified individual should perform a physical examination to detect arteriovenous graft dysfunction at least monthly. The 3 preferred surveillance techniques for stenosis of arteriovenous graft are:
- intra access flow using sequential measurements with time analysis
- directly measured or derived static venous dialysis
- duplex ultrasound
Other acceptable techniques include physical findings of persistent swelling of the arm, presence of collateral veins, prolonged bleeding after needle withdrawal, or altered characteristics of pulse or thrill in the arteriovenous graft. Unstandarized dynamic venous pressures should not be used.