Chronic left heart catheterization for microvascular blood flow determination in the rabbit: a minimally invasive technique using specially designed port devices.
BACKGROUND
This study describes a modified catheterization technique with subcutaneously implanted port catheters to be inserted in a retrograde manner across the aortic valve into the left heart ventricle through the right carotid artery to measure organ perfusion.


METHODS
The specially designed arterial port catheters were implanted in New Zealand rabbits (n = 11, 3.7 +/- 0.1 kg [mean +/- SEM]) under iv anesthesia (medetomidine/ketamine) and single-shot perioperative antibiotic therapy. Hemodynamics were registered continuously during the operation via an ear artery catheter.


RESULTS
Implantation of ports was performed in all animals (11/11) without major complications (mean operation time: 70 +/- 3 min). We did not observe catheter-associated arrhythmia, fall in mean arterial pressure (MAP before and post OP: 70 +/- 2 and 68 +/- 2 Torr, respectively), or change in arterial oxygen saturation (SaO2 before and post OP: 89 +/- 3 and 95 +/- 2%, respectively). With a specifically modified microsurgical insertion technique, cerebral blood supply was effectively preserved as evidenced from postmortem histological examinations, cerebral blood flow determination with fluorescent microspheres, and measurement of S-100b protein serum concentrations, a specific marker of neuronal damage. The positioning of the catheter tip in the left ventricle was found to be correct in 10/11 animals.


CONCLUSIONS
Repeated and atraumatic microsphere injections into the left ventricle have become feasible by transcutaneous puncture of subcutaneous port systems over several weeks under light sedation. Hence, this new approach (i) avoids the necessity of repeated intracardiac injections and port insertions via thoracotomy, thus reducing the perioperative stress for the animals, and (ii) allows for the first time minimally invasive repetitive and chronic measurements of regional organ blood flow under various experimental settings.
Hoffmann
Johannes N
JN
Department of Surgery, Klinikum Grosshadern, Germany.
Steinhagen
Sonja
S
Kast
Christina
C
Scheuber
Heinz P
HP
Jochum
Marianne
M
Gippner-Steppert
Cornelia
C
Inthorn
Dietrich
D
Schildberg
Friedrich W
FW
Nolte
Dirk
D
D000818:Animals; D001794:Blood Pressure; D006328:Cardiac Catheterization / Q000295:instrumentation* / Q000379:methods*; D002408:Catheters, Indwelling; D002560:Cerebrovascular Circulation / Q000502:physiology; D003326:Coronary Circulation / Q000502:physiology*; D006352:Heart Ventricles; D008833:Microcirculation / Q000502:physiology; D008863:Microspheres; D019060:Minimally Invasive Surgical Procedures / Q000379:methods; D010100:Oxygen / Q000097:blood; D018962:Phlebotomy / Q000295:instrumentation / Q000379:methods; D011817:Rabbits
D010100:Oxygen