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Assessment of Stenosis in Vascular Access Grafts
Author(s) -
Tricht Ilse Van,
Wachter Dirk De,
Vanhercke Daniel,
Tordoir Jan,
Verdonck Pascal
Publication year - 2004
Publication title -
artificial organs
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.684
H-Index - 76
eISSN - 1525-1594
pISSN - 0160-564X
DOI - 10.1111/j.1525-1594.2004.07368.x
Subject(s) - stenosis , medicine , pulsatile flow , anastomosis , occlusion , ultrasound , cardiology , hemodialysis , vascular access , doppler ultrasound , radiology , complication , venous pressure , hemodynamics , surgery
The major complication that occurs with grafts used as vascular access for hemodialysis, is stenosis at the venous anastomosis or in the draining vein. 75% area stenosis is considered significant as thrombotic occlusion may occur. The aim of this experimental study was to evaluate invasive and noninvasive indices to detect significant stenoses in a vascular access graft. A compliant underarm loop graft in vitro model was built and studied with 50, 65, 80, and 90% stenosis at flow rates of 500, 1000, and 1500 mL/min. Flow in the system was pulsatile. Velocity was measured with ultrasound Doppler and the pressure was measured invasively. The resistance index (RI), p venous line /MAP, and the newly introduced pressure ratio (PR) were calculated and compared. A stenosis can be suspected when a high frequency ultrasound velocity signal develops at the venous anastomosis. RI > 1 confirms a very severe stenosis (90%). The parameter PR < 8% confirms significant stenoses showing its clinical relevancy.