Direct intra-aneurysm sac pressure measurement using tip-pressure sensors: in vivo and in vitro evaluation.
OBJECTIVE
Direct intra-aneurysm sac pressure measurement with percutaneous translumbar puncture is a new method for follow-up after endovascular aneurysm repair. The purpose of this study was to evaluate a tip-pressure sensor system for intra-aneurysm pressure measurement in an in vitro aneurysm model and in vivo in patients by studying intraobserver variability.


METHODS
We used 0.014-inch guide wire-mounted tip-pressure sensors. For the in vitro aneurysm model, saccular aneurysms filled with thrombus were inserted in a left-heart-driven aneurysm model. Pressure was measured simultaneously with guide wire pressure sensors in the lumen of the model and within the aneurysm thrombus. In vivo, intraobserver variability was evaluated with double percutaneous translumbar puncture of the abdominal aortic aneurysm (AAA) with pressure measurement in 15 patients (14 men, 1 woman; median age, 75 years [63-80 years]; median AAA diameter, 55 mm [47-80 mm]) at a median of 32 months (2-100 months) after endovascular aneurysm repair. Mean pressure index was calculated as the percentage of mean intraaneurysm pressure relative to simultaneous mean systemic pressure.


RESULTS
In vitro, the difference in pressure between the tip-sensor measurements and the pressure output of the aneurysm model was 2 mm Hg (1-4 mm Hg) when the output varied between 150/50 and 200/100 mm Hg (n = 90). Mean pressure in the lumen of the model and within the aneurysm thrombus differed by 1 mm Hg (-5-15 mm Hg (n = 10). In vivo, intraobserver variability of mean pressure index (Bland-Altman plot) was 0% (-7%-17%; n = 15%).


CONCLUSIONS
Direct intra-aneurysm sac pressure measurement with tip-pressure sensors mounted on 0.014-inch guide wires is a reliable and reproducible technique for measuring intra-AAA pressure both in vitro and in vivo.
Endovascular Center, Department of Radiology, Malmö University Hospital, Sweden. nunovdias@hotmail.com
Nuno V
NV
Dias
Krassi
K
Ivancev
Martin
M
Malina
Jan-Willem
JW
Hinnen
Michel
M
Visser
Bengt
B
Lindblad
Björn
B
Sonesson
D000368:Aged; D000369:Aged, 80 and over; D017130:Angioplasty / Q000379:methods; D017544:Aortic Aneurysm, Abdominal / Q000503:physiopathology* / Q000601:surgery*; D001795:Blood Pressure Determination / Q000295:instrumentation; D019917:Blood Vessel Prosthesis Implantation / Q000379:methods; D002404:Catheterization / Q000295:instrumentation; D003935:Diagnostic Techniques, Cardiovascular / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008955:Models, Cardiovascular; D015588:Observer Variation; D011184:Postoperative Period; D015203:Reproducibility of Results