Acoustically active injection catheter guided by ultrasound: navigation tests in acutely ischemic porcine hearts.
Catheters are increasingly used therapeutically and investigatively. With complex usage comes a need for more accurate intracardiac localization than traditional guidance can provide. An injection catheter navigated by ultrasound was designed and then tested in an open-chest model of acute ischemia in eight pigs. The catheter is made "acoustically active" by a piezo-electric crystal near its tip, electronically controlled, vibrating in the audio frequency range and uniquely identifiable using pulsed-wave Doppler. Another "target" crystal was sutured to the epicardium within the ischemic region. Sonomicrometry was used to measure distances between the two crystals and then compared with measurements from 2-D echocardiographic images. Complete data were obtained from seven pigs, and the correlation between sonomicrometry and ultrasound measurements was excellent (p < 0.0001, ρ = 0.9820), as was the intraclass correlation coefficient (0.96) between two observers. These initial experimental results suggest high accuracy of ultrasound navigation of the acoustically active catheter prototype located inside the beating left ventricle.
Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Scottsdale, Arizona, USA. Electronic address: Belohlavek.marek@mayo.edu.
Marek
M
Belohlavek
Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Scottsdale, Arizona, USA.
Minako
M
Katayama
Independent Engineering Consultant, Laguna Niguel, California, USA.
David
D
Zarbatany
Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Scottsdale, Arizona, USA.
F David
FD
Fortuin
Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Mostafa
M
Fatemi
Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Rochester, Minnesota, USA.
Ivan Z
IZ
Nenadic
Division of Cardiovascular Diseases, Mayo Clinic College of Medicine, Scottsdale, Arizona, USA.
Eileen M
EM
McMahon
D000818:Animals; D006328:Cardiac Catheterization / Q000379:methods*; D004452:Echocardiography / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007267:Injections / Q000379:methods; D008297:Male; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine; D018084:Ultrasonography, Interventional / Q000379:methods*
Acoustic catheter; Pulsed-wave Doppler; Ultrasound navigation