A prospective study of changes in aneurysm and graft length after endovascular exclusion of AAA using balloon and self-expanding endograft systems

Purpose: longitudinal shrinkage of aneurysms post-endovascular repair, empl oying unvalidated measurement techniques has been held to account for endog raft disruption. In this study we record changes in aneurysm length, diamet er and volume using the gold standard of calibrated spiral CT angiography ( SCTA). Method: from 179 patients with AAA scanned by SCTA, 68 were selected for en dografting. Twenty-seven had PFTE home-made prostheses while 41 patients ha d Talent endografts. SCTA was performed on the fifth postoperative day and 6-monthly intervals thereafter. The distance between the lowest renal arter y and the aortic bifurcation (VBL - vertical body length) and the luminal c entre line length (LCL) were measured. Maximal sac diameters and volumes we re recorded using 3DCT reconstruction. Results: significant increase was noted in VBL (3.2) mm for PTFE-treated pa tients accompanied by an increase in sac volume at day 5 (12.4 ml). No chan ges in LCL or maximal diameters were evident. At 1.5 years further lengthen ing of both VBL (6.4 mm) and LCL (9.3 mm) was unaccompanied by sac diameter /volume changes. Talent patients-no changes in VBL or LCL were evident. Vol umes and maximal AP and transverse diameters showed marked shrinkage: AP -1 1.2 mm; transverse -2.6 mm; volumes by -35.5 ml at 6 months. Conclusion: with PTFE increase in VBL but not graft length, without concurr ent changes in maximal diameters at day 5, is commensurate with increase in sac volume; after 1.5 years graft lengthening overtakes aortic lengthening . In talent patients VBL/graft length remained unchanged. There is no evide nce for longitudinal aneurysmal contractive. Volumes and maximal diameters for the Talent endograft but not for PTFE show shrinkage.