ARFI Ultrasound for In Vivo Hemostasis Assessment Postcardiac Catheterization, Part I: Preclinical Studies

Abstract

The world wide prevalence of cardiovascular disease leads to over seven million annual percutaneous coronary catheterization procedures, the majority of which exploit femoral artery access. Femoral puncture sites (‘arteriotomies’) can be associated with severe vessel complications after sheath removal if hemostasis is not properly achieved. Hemostasis onset is routinely determined by examination for bleeding at the skin puncture; however, clotting along the puncture path can obscure subcutaneous bleeding, and therefore hemostasis is blindly assessed. We hypothesize that hemostasis assessment can be un-blinded by Acoustic Radiation Force Impulse (ARFI) ultrasound. In this first of a two-part series, we present in vivo ARFI hemostasis imaging data obtained in relevant canine models of femoral artery puncture. Above arteriotomies, ARFI-induced displacements were large (3.5 to > 5.0 μm) relative to surrounding soft tissue soon after needle removal, which was consistent with our expectation for pooled extravasated blood. ARFI-induced displacements above arteriotomies decreased in magnitude (to ∼ 2 μm) some time after needle removal and suggested the onset of hemostasis. This preclinical investigation served as proof of concept and justification for a pilot human study, which is presented in part two of this series.

ARFI Ultrasound for In Vivo Hemostasis Assessment Postcardiac Catheterization, Part II: Pilot Clinical Results

“…ARFI imaging beam sequences were as described in part one of this two-part series, except that the axial focal depth ranged from 15 - 35 mm to target the location of the near arterial wall in the human subjects. 1…”

“…We have shown that ARFI ultrasound is a viable imaging method for noninvasively monitoring hemostasis in vivo at femoral arteriotomies in a relevant canine model 1. Extending our preclinical feasibility work to pilot clinical studies requires careful consideration of potential approaches to validating ARFI results.…”

“…As discussed in part one of this two-part manuscript series, hemostasis at femoral arteriotomies following percutaneous cardiac catheterization is commonly achieved by manual compression at the arteriotomy and sustained by prolonged time to ambulation 1. Manual compression can be associated with patient discomfort, while prolonged bed rest is uncomfortable to the patient and costly to medical centers 2.…”

ARFI Ultrasound Monitoring of Hemorrhage and Hemostasis In Vivo in Canine Von Willebrand Disease and Hemophilia

“…We have previously demonstrated acoustic radiation force impulse (ARFI) ultrasound, an ultrasonic method for noninvasively interrogating the mechanical properties of tissue, for distinguishing subcutaneous and periarterial hemorrhage at femoral artery punctures in patients undergoing cardiac catheterization (Behler et al 2009a, 2009b). We have now progressed to applying ARFI to monitoring rate of bleeding and detecting hemostasis following a standardized hemostatic challenge in relevant canine models of hemophilia A and VWD.…”

Analysis of cross-correlation coefficients for subcutaneous blood signal detection by ARFI Imaging

“…Therefore, it is important to rapidly diagnose active bleeding and to determine the severity of the bleeding to make an appropriate triage decision. Previously, we have shown that ARFI ultrasound is a viable imaging method for noninvasively monitoring hemostasis in vivo at femoral arteriomies in both a relevant canine model and human subjects [2,3]. ARFI subcutaneous blood detection can facilitate clinical interpretation of these ARFI imaging results.…”