In vitro analysis of type II endoleaks and aneurysm sac pressurization on longitudinal stent-graft displacement

Martyn Knowles, Tiago Pellisar, Erin H. Murphy, Gregory A. Stanley, Abraham F. Hashmi, M. Zachary Arko, Frank R. Arko

Research output: Contribution to journalArticle

6 Scopus citations

Abstract

Purpose: To evaluate the effects of type II endoleaks and sac pressurization on stent-graft displacement following endovascular aneurysm repair (EVAR). Methods: Experimental silicone infrarenal aneurysm (6-cm) models were "treated" with a Talent stent-graft deployed with 20-mm proximal and distal landing zones. Inflow and outflow vessels were created as part of the silicone model to control flow into the aneurysm sac. All aneurysm models were uniform, with a diameter neck of 31 mm, a neck length of 20 mm, and iliac artery diameters of 16 mm. The aortic model was secured in a water bath to a pulsatile pump under physiological conditions; the output phase ratio (%systole/%diastole) was set at 65/35 with a pump rate of 80 beats per minute. Commercially available bifurcated stent-grafts were then displaced in vitro utilizing a linear motion apparatus attached to a force gauge. The mean arterial pressure (MAP) and pulse pressure (PP) at the aortic inflow were 60.1±3.1 and 38.3±7.8 mmHg, respectively. Peak force to cause initial stent-graft migration with and without a type II endoleak was recorded and compared. Results: In aneurysm sacs with no endoleak, the MAP and sac PP were 32±6.4 and 6±1.3 mmHg, respectively (p<0.01). In aneurysm sacs with a type II endoleak, the MAP and sac PP were 54.1±9.7 and 16.1±4.1 mmHg, respectively (p<0.02). Peak force to initiate migration was 16.0±1.41 N (range 15-18) with no endoleak vs. 23.2±2.2 N (range 20-25) in those with a type IIa endoleak and 23.5±2.5 N (range 20-26) in those with a type IIb endoleak (p<0.001). Conclusions: Type II endoleaks are associated with a significantly increased sac pressure. Increased sac pressurization from type II endoleaks results in a significantly greater force to displace a stent-graft longitudinally. Type II endoleaks may therefore inhibit migration and offer a benefit following EVAR; however, clinical correlation of these results is required.

Original languageEnglish (US)
Pages (from-to)601-606
Number of pages6
JournalJournal of Endovascular Therapy
Volume18
Issue number4
DOIs
StatePublished - Aug 1 2011

Keywords

  • Abdominal aortic aneurysm
  • Aneurysm model
  • Aneurysm sac
  • Displacement force
  • Experimental model
  • Migration
  • Pressure
  • Stent-graft
  • Type II endoleak

ASJC Scopus subject areas

  • Surgery
  • Radiology Nuclear Medicine and imaging
  • Cardiology and Cardiovascular Medicine

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    Knowles, M., Pellisar, T., Murphy, E. H., Stanley, G. A., Hashmi, A. F., Arko, M. Z., & Arko, F. R. (2011). In vitro analysis of type II endoleaks and aneurysm sac pressurization on longitudinal stent-graft displacement. Journal of Endovascular Therapy, 18(4), 601-606. https://doi.org/10.1583/11-3469.1