[Influence of fixation mechanism on changes of the supra- and infrarenal segment of the aorta after endovascular treatment of infrarenal aortic aneurysm].
BACKGROUND
Dilatation of the infrarenal aortic segment determines the long-term outcome after endovascular repair of abdominal aortic aneurysms. This segment is crucial for sealing and preventing stent-graft migration. The purpose of this study was to evaluate influence of fixation mechanism on changes of supra- and infrarenal aortic diameters over a 10-year period.


METHODS
We reviewed all our endovascular procedures for abdominal aortic aneurysms and follow-up CT scans between 1998 and 2008. Only patients with the three most frequently implanted self-expandable stent-graft types and a minimal follow-up of three months were included in this study. Further inclusion criteria were elective repair and follow-up at our department to consistent data formats. A total of 103 patients, 35 with suprarenal fixation without hooks (Medtronic Talent®, Medtronic World Medical, Sunrise, FL, USA), 29 with suprarenal fixation with hooks (Cook Zenith®, Cook Inc. Bloomington, IN, USA) and 39 with infrarenal fixation with anchors (Gore Excluder®, W. L. Gore & Associates, Flagstaff, Ariz, USA) met the inclusion criteria. All measurements were performed in duplicate by two different investigators to determine intra- and interobserver errors. Based on this error a minimal change of 2 mm of infrarenal aortic neck diameter was determined as aortic neck dilatation.


RESULTS
During a mean follow-up time of 39.4 (3-108.8) months, infrarenal aortic neck dilatation was found in 28.57% in the Medtronic group, 10.26% in the Gore group and 31.03 in the Cook group. Suprarenal changes were 17.14%, 20.51% and 17.24%, respectively. Reduction of the maximal diameter could be achieved in 74.3% (Medtronic), 79.5% (Gore), and 75.8% (Cook). Seven of 23 patients with a notable dilatation of the infrarenal neck required reintervention. All of them were stent-grafts with suprarenal fixation. No statistical significance was found between the 3 groups regarding changes of suprarenal or infrarenal diameters or migration rates.


CONCLUSIONS
Although no statistical significance was found among the groups, infrarenal fixation showed the lowest rate of infrarenal dilatation.
Uniklinik Ulm, Klinik für Thorax- und Gefäßchirurgie, Ulm, Deutschland. alexander.oberhuber@uniklinikulm.de
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A
Oberhuber
A
A
Schwarz
M
M
Hoffmann
O
O
Klass
H
H
Schelzig
K H
KH
Orend
B
B
Mühling
D000368:Aged; D017130:Angioplasty; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000601:surgery*; D001027:Aortography; D019917:Blood Vessel Prosthesis Implantation; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging; D057867:Endoleak / Q000000981:diagnostic imaging / Q000517:prevention & control* / Q000601:surgery; D005260:Female; D005548:Foreign-Body Migration / Q000000981:diagnostic imaging / Q000517:prevention & control* / Q000601:surgery; D006801:Humans; D007091:Image Processing, Computer-Assisted; D021621:Imaging, Three-Dimensional; D008297:Male; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000517:prevention & control* / Q000601:surgery; D011474:Prosthesis Design; D012307:Risk Factors; D013223:Statistics as Topic; D015607:Stents; D013536:Suture Techniques / Q000295:instrumentation*; D014057:Tomography, X-Ray Computed