Systemic pulsatile pressure in type II endoleaks after stent grafting of experimental abdominal aortic aneurysms.
OBJECTIVE
To investigate pressure and maximum rate of rise of systolic pressure (peak dP/dt) in completely excluded aneurysms and endoleaks to determine the hemodynamic impact of endoleaks.


METHODS
In mongrel dogs (n = 36) experimental aneurysms were created by insertion of a patch (portion of rectus abdominis muscle sheath) into the infrarenal aorta. In group I (n = 18), all aortic branches of the aneurysm were ligated and all aneurysms were completely excluded by stent grafts. Group II (n = 18) consisted of aneurysms with patent aortic side branches that represented sources of endoleaks. One week (n = 12), six weeks (n = 12), and six months (n = 12) after stent grafting, hemodynamic measurements were obtained in thrombosed aneurysms and proved endoleaks. Systemic blood pressure and intraaneurysmal pressure were simultaneously measured and the respective peak dP/dt were computed.


RESULTS
At the six-month follow-up, the systolic-pressure ratio (intraaneurysmatic pressure: systemic pressure) was significantly increased in endoleaks compared to non-perfused areas (0.879 +/- 0.042 versus 0.438 +/- 0.176, p < 0.01, group II) or completely excluded aneurysms (0.385 +/- 0.221, group I). Peak dP/dt ratio (intraaneurysmal peak dP/dt: systemic peak dP/dt) was 0.922 +/- 0.154 in endoleaks, compared to 0.084 +/- 0.080 in non-perfused areas (group II, p < 0.01), and was 0.146 +/- 0.121 in completely excluded aneurysms (group I). The diastolic-pressure ratio was also increased in endoleaks compared to non-perfused areas (0.929 +/- 0.088 versus 0.655 +/- 0.231, p < 0.01, group II) or completely excluded aneurysms (0.641 +/- 0.278, group I). In excluded aneurysms, pressure exposure declined as the length of the follow-up period increased.


CONCLUSIONS
Type II endoleaks transmit pulsatile pressure of near systemic level and indicate insufficient treatment result. In contrast, complete endovascular exclusion of aneurysms results in significantly reduced pressure exposure.
Pitton
Michael Bernhard
MB
Department of Radiology, University Hospital, Johannes Gutenberg University of Mainz, Langenbeckstrasse 1, 55101 Mainz, Germany. pitton@radiologie.klinik.uni-mainz.de
Schmenger
Patrick
P
Düber
Christoph
C
Neufang
Achim
A
Thelen
Manfred
M
D000818:Animals; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology*; D019917:Blood Vessel Prosthesis Implantation; D003097:Collateral Circulation / Q000502:physiology; D003971:Diastole / Q000502:physiology; D004195:Disease Models, Animal; D004285:Dogs; D005500:Follow-Up Studies; D008955:Models, Cardiovascular; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D011673:Pulsatile Flow / Q000502:physiology*; D015607:Stents; D013599:Systole / Q000502:physiology; D013997:Time Factors; D014057:Tomography, X-Ray Computed