An experimental model for the acute and chronic evaluation of intra-aneurysmal pressure.
OBJECTIVE
To develop an animal model for the acute and chronic monitoring of pressure within abdominal aortic aneurysms (AAAs) to be treated with endovascular grafts.


METHODS
A strain-gauge pressure transducer was placed within an AAA created from a prosthetic vascular graft. Prosthetic aneurysms were implanted into 17 canine infrarenal aortas. The intra-aneurysmal pressure was monitored and correlated with noninvasive forelimb sphygmomanometry for 2 weeks. After this time, an intravascular manometer catheter was passed into the aneurysm. Simultaneous pressure measurements were obtained using the implanted strain-gauge pressure transducer, the manometer catheter, and the forelimb sphygmomanometer. Angiography was performed to assess intraluminal morphology, aneurysm anastomoses, and adjoining aortic vessels. In addition, two control animals underwent intra-aneurysmal pressure monitoring after standard surgical aneurysm repair.


RESULTS
There was excellent correlation (r = 0.97) between the pressure measurements obtained with the implanted strain-gauge pressure transducer and the intravascular manometer. Close correlation was also observed between the implanted strain-gauge transducer and the forelimb sphygmomanometer (r = 0.88) during postprocedural monitoring. Intra-aneurysmal pressure was lowered dramatically by surgical exclusion (aneurysm: 15/5 +/- 7/4 mmHg; systemic: 124/66 +/- 34/17 mmHg; p < 0.001). The prosthetic aneurysms were successfully imaged with angiography.


CONCLUSIONS
This animal model provides an accurate and reproducible means for measuring intra-aneurysmal pressure on an acute and chronic basis. It may be possible to use this model in the assessment of endovascular devices to determine their efficacy in reducing intra-aneurysmal pressure. Evaluation of complications associated with their use, such as patent aneurysm side branches, perigraft channels, and perianastomotic reflux, may also be possible.
Faries
P L
PL
Department of Surgery, Montefiore Medical Center, New York, New York, USA.
Sanchez
L A
LA
Marin
M L
ML
Parsons
R E
RE
Lyon
R T
RT
Oliveri
S
S
Veith
F J
FJ
D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000473:pathology; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery; D001027:Aortography; D001794:Blood Pressure; D001795:Blood Pressure Determination / Q000295:instrumentation; D001807:Blood Vessel Prosthesis; D004195:Disease Models, Animal; D004285:Dogs; D005260:Female; D015203:Reproducibility of Results