A new method for precise determination of endograft position and apposition in the aortic neck after endovascular aortic aneurysm repair.
BACKGROUND
Follow-up imaging after endovascular aortic aneurysm repair (EVAR) focuses on detection of gross abnormalities: endoleaks and significant (>10 mm) migration. Precise determination of endograft position and wall apposition may predict late complications. We present a new measurement method to determine precise position and apposition of endografts in the aortic neck.


METHODS
Four patients were selected from our EVAR database. These patients had late (>1 year) type IA endoleak or >1 cm endograft migration. Twenty patients with uneventful follow-up were measured as controls. The new software adds six parameters to define endograft position and neck apposition: fabric distance to renal arteries, tilt, endograft expansion (% of the maximum original diameter), neck surface, apposition surface, and shortest apposition length. These parameters were determined on preoperative and all available postoperative CT-scans, to detect subtle changes during follow-up.


RESULTS
All patients with endoleak or migration had increases in fabric distance, tilt, or endograft expansion or decrease of apposition surface. Changes occurred at least one CT scan before the endoleak or migration was noted in the CT reports. The patient without complications showed no changes in position or apposition during follow-up.


CONCLUSIONS
The new measurement method detected subtle changes in endograft position and apposition during CT follow-up, not recognized initially. It can potentially determine endograft movements and decrease of apposition surface before they lead to complications like type IA endoleaks or uncorrectable migration. A larger follow-up study comparing complicated and non-complicated EVAR patients is needed to corroborate these results.
Department of Vascular Surgery, St. Antonius Hospital, Nieuwegein, The Netherlands - k.van.noort@antoniusziekenhuis.nl.
Kim
K
VAN Noort
Richte C
RC
Schuurmann
Cornelis H
CH
Slump
Jan A
JA
Vos
Jean P
JP
Devries
D000792:Angiography / Q000379:methods*; D001014:Aortic Aneurysm / Q000000981:diagnostic imaging / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D000072226:Computed Tomography Angiography; D016208:Databases, Factual; D057867:Endoleak / Q000000981:diagnostic imaging* / Q000209:etiology; D057510:Endovascular Procedures / Q000009:adverse effects / Q000295:instrumentation*; D005548:Foreign-Body Migration / Q000000981:diagnostic imaging* / Q000209:etiology; D006801:Humans; D061330:Multidetector Computed Tomography; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome