The PAI procedure represents a well-suited alternative to the DRIL technique for the treatment of patients who develop ischemia after creation of an arteriovenous access. Results for access salvage and disappearance of ischemic symptoms are equivalent to the DRIL technique. In contrast to the DRIL procedure, the PAI technique preserves the natural arterial pathway. Hence, PAI is preferable for surgeons who are reluctant to ligate an axial artery and are concerned about potentially disastrous consequences.

The AAPL is an unusual but useful and easy-to-perform alternative procedure to create vascular access for hemodialysis. It can provide survival for strictly selected patients in whom conventional vascular access is not possible. The axillary chest AAPL is preferred.

A cuffed anastomosis type may be favourable in terms of local haemodynamics so enhancing the long-term patency of PTFE-venous grafts.

Low shear areas at the distal anastomosis of peripheral bypasses are thought to promote neointimal hyperplasia. In this study we evaluated the fluid dynamic environment at the distal anastomosis of peripheral bypasses by means of a new method for in vitro flow visualization and quantitative velocity field measurement. A silastic model of a distal end-side anastomosis was attached to a mock circulation loop driven by an artificial heart. High resolution velocity fields were measured by means of particle image velocimetry (PIV). The velocity vector data were used to calculate vorticity omega, strain rates ex, shear rates h and shear stresses tau. Two separations and a stagnation zone were identified by means of flow visualization. Measured velocities inside the three zones were significantly lower than in the high velocity mainstream. Calculated shear rates and shear stresses inside the zones were significantly lower than human wall shear rates. At the transition between the effective mainstream and the boundary layers high vorticity and compressive strain fields existed, indicating the presence of high shear forces. The locations of these areas corresponded to the well known zones of intimal hyperplasia. The high resolution shear stress analysis supports the low shear theory of intimal hyperplasia development. A wall diversion angle greater than 6 degrees leads to flow separation and presumed IH promotion until high shear transition areas are reached.

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