Prophylactic residual aneurysmal sac embolization with expandable hydrogel embolic devices for endoleak prevention: preliminary study in dogs.
OBJECTIVE
To explore the feasibility and efficacy of residual aneurysmal sac (RAS) embolization with the expandable hydrogel embolic device (EHED) in prevention of endoleaks in a surgically created and endoluminally treated abdominal aortic aneurysm (AAA).


METHODS
In eight dogs, an AAA was created by means of side-to-side anastomosis between the infrarenal abdominal aorta and inferior vena cava (IVC) with ligation of the IVC above and below the anastomotic end, followed by deployment of an endograft with holes. The RAS was then embolized with the EHED. One animal was killed immediately after RAS embolization and one animal died 12 hr after the procedure. Follow-up aortograms were obtained in six animals after 1 day (1 animal), 2 weeks and 6 months (1 animal), and 8 weeks (4 animals).


RESULTS
Four animals had no endoleaks on the follow-up aortograms. The remaining two animals with incomplete RAS embolization had moderate type III endoleaks. Type I or II endoleaks were not seen in any animals. Complications included RAS wall penetration by the devices with platinum wires in two animals (nos. 1 and 2), device migration into an aortic circulation through the endograft holes in two animals (nos. 2 and 3) or through distal interstices between the aortic wall and endograft in one animal (no. 8), aortic occlusion in three animals (nos. 3, 7, and 8), and RAS rupture in one animal (no. 7). Histologic examination showed expanded hydrogels occupying the RAS with associated mature or immature organized thrombus, fibrinous thrombus, or degenerate blood cells.


CONCLUSIONS
RAS embolization was feasible with the EHED, although additional modifications to the device are required to avoid complications. Angiographic and histologic results suggested that RAS embolization with the EHED may help in the prevention of endoleaks.
Hiraki
Takao
T
Dotter Interventional Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239-3098, USA.
Pavcnik
Dusan
D
Uchida
Barry T
BT
Timmermans
Hans A
HA
Yin
Qiang
Q
Wu
Reng-Hong
RH
Niyyati
Mahtab
M
Keller
Frederick S
FS
Rösch
Josef
J
D000818:Animals; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D001027:Aortography; D019917:Blood Vessel Prosthesis Implantation; D004195:Disease Models, Animal; D004285:Dogs; D004621:Embolization, Therapeutic / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000008:administration & dosage*
D020136:Hydrogel, Polyethylene Glycol Dimethacrylate