Usefulness of ultrasound in vascular access management of hemodialysis patients

Abstract

Maintaining adequate vascular access for hemodialysis is a major problem for patients with end-stage renal disease from the standpoint of QOL. Ultrasonography is a mobile, simple, and noninvasive technique that provides both anatomic (blood vessel lumen and wall) and physiologic (access flow measurement) data. Preoperative ultrasound scan artery and vein mapping by the B-mode method is useful for decreasing the failure rate of forearm fistula. The B-mode and color Doppler methods are able to successfully detect stenosis, thrombus, and aneurysm. The pulse Doppler method is useful for observation of the pattern of the bloodstream and measurement of the blood flow and blood volume in order to analyze the hemodynamics of vascular access. From the measurement of resistance index (RI) and blood flow, subclinical stenosis of vascular access can be detected early, and prophylactic PTA of the stenotic region before complete obstruction has been shown to prolong the patency period of vascular access. New laboratory procedures such as ultrasonic 3-D imaging system (Vol-mode) or Fusion 3D that combine a B-mode image and a power Doppler 3D image and display are useful for evaluation of the objectivity of vascular access. In addition, the B-mode method is useful for monitoring during puncture to a central vein or to the forearm vascular access in which insertion of a canula is difficult, and the B-mode and color Doppler methods are useful for monitoring interventional treatment.