title: Type I and collateral flow in experimental aneurysm models treated with stent-grafts.
abstract: OBJECTIVE
  To evaluate the influence of a collateral branch on the evolution of type I leaks after endovascular aneurysm repair in an experimental model.
  
  
  METHODS
  Bilateral aneurysms were constructed in the common iliac arteries of 12 dogs by using venous patches. A collateral branch was added on one aneurysm on one side by implantation of the sacroiliac trunk on the sac. Balloon-expandable stent-grafts were implanted 2 months later. In six dogs, type I endoleaks were created on the side with the collateral branch by using plastic deformation of the stent-graft (group 1). Stent-grafts were fully expanded on the contralateral side in the same dogs (group 2, control group). In the remaining six dogs, type I endoleaks were created on the side without the collateral branch (group 3), and stent-grafts were fully expanded on the side with the collateral branch, creating a type II endoleak (group 4). Follow-up imaging was performed with Doppler ultrasonography and angiography until the animals were sacrificed at 3 months. Leaks were classified as major, moderate, or absent with use of findings at imaging and pathologic examinations.
  
  
  RESULTS
  No endoleaks were observed in group 2 (control group). Endoleaks were persistent in 83% of aneurysms in groups 1 (5/6 type I), 3 (5/6 type I), and 4 (5/6 type II). Type I leaks were major in three of six cases when associated with a collateral branch (group 1) and moderate when they were not (group 3; P < .05). Before sacrifice, larger aneurysmal diameters were observed only in group 1 (110% +/- 18) as compared with control group 2 (85% +/- 12) (P < .05).
  
  
  CONCLUSIONS
  More prominent leaks and larger aneurysms are observed when a collateral branch is associated with a type I endoleak.
authors.affiliation: Department of Radiology, Centre Hospitalier de l'Université de Montréal, Notre-Dame Hospital, Quebec, H2L 4M1, Canada. gilles.soulez.chum@ssss.gouv.qc.ca
authors.forename: Gilles
authors.initials: G
authors.lastname: Soulez
authors.forename: Sophie
authors.initials: S
authors.lastname: Lerouge
authors.forename: Igor
authors.initials: I
authors.lastname: Salazkin
authors.forename: Tim
authors.initials: T
authors.lastname: Darsaut
authors.forename: Vincent L
authors.initials: VL
authors.lastname: Oliva
authors.forename: Jean
authors.initials: J
authors.lastname: Raymond
mesh_terms: D000714:Anastomosis, Surgical; D000818:Animals; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects*; D002404:Catheterization; D003097:Collateral Circulation; D004195:Disease Models, Animal; D004285:Dogs; D017543:Iliac Aneurysm / Q000000981:diagnostic imaging / Q000601:surgery*; D007601:Jugular Veins / Q000637:transplantation; D011475:Prosthesis Failure; D011859:Radiography; D012212:Rheology; D015607:Stents; D014463:Ultrasonography