ORIGINAL ARTICLES   

International Angiology 2004 September;23(3):270-5

Copyright © 2004 EDIZIONI MINERVA MEDICA

lingua: Inglese

High wall shear stress measured by magnetic resonance is a predictor of restenosis in the femoral artery after balloon angioplasty

Amann-Vesti B. R. ¹, Kozerke S. ², Krieger E. ¹, Boesiger P. ², Koppensteiner R. ¹

¹ Division of Angiology, University Hospital, Zurich. Switzerland 2 Institute for Biomedical Engineering, University and ETH, Zurich, Switzerland

Aim. Wall shear ­stress (WSS) has been ­implied in the path­o­gen­e­sis of resten­o­sis after per­cut­ane­ous trans­lu­mi­nal angio­plas­ty (PTA). Aims of the ­present study were to cal­cu­late WSS in the super­fi­cial femo­ral ­artery (SFA) from mag­net­ic res­o­nance imag­ing (MRI) and from ­duplex sonog­ra­phy in ­healthy con­trols and in ­patients after PTA of the SFA to eval­u­ate the pre­dic­tive value of WSS for resten­o­sis.
Meth­ods. WSS was ­assessed by cal­cu­lat­ing the slope of veloc­ity pro­files at the ves­sel wall from data ­obtained with veloc­ity encod­ed cine MR and with ­duplex using the for­mu­la: Shear ­stress=4×blood vis­cos­ity×peak blood veloc­ity/inter­nal diam­e­ter. Sev­en­teen ­patients were stud­ied 1 day after suc­cess­ful PTA of the SFA. Resten­o­sis was deter­mined by ­duplex ultra­sound at the 6-­months fol­low-up visit.
­Results. In ­healthy con­trols WSS val­ues cal­cu­lat­ed from MRI and from ­duplex were sim­i­lar (1.86±0.35 N/m2 vs 1.88±0.34 N/m2, n.s.). In ­patients the val­ues ­obtained with ­duplex were high­er than those ­obtained with MRI (4.1±2.3 N/m2 vs 2.4±1.2 N/m2, p=0.002). With both meth­ods post­inter­ven­tion­al WSS was high­er in ­patients devel­op­ing resten­o­sis (­duplex 5.4±2.2 N/m2, MRI 3.1±0.9 N/m2) than in those with­out resten­o­sis (­duplex 2.7±1.4 N/m2, MRI 1.5±0.7 N/m2) and was ­revealed to be an inde­pen­dent pre­dic­tor of resten­o­sis (p=0.03).
Con­clu­sion. This is the first study dem­on­strat­ing that ­increased post­inter­ven­tion­al WSS in the SFA is pre­dic­tive for resten­o­sis. WSS val­ues ­obtained with MRI and ­duplex were dif­fer­ent in ­patients, how­ev­er with both meth­ods high­er WSS was asso­ciat­ed with resten­o­sis.