ANEURISMATIC NECK THROMBUS, TYPE OF ENDOPROSTHESIS AND DEVELOPMENT OF TYPE IA ENDOLEAK — COULD THIS ASSOCIATION BE A PROBLEM?
Introduction: The long-term results of EVAR depend on the proximal fixation of the endoprosthesis to avoid migration and development of endoleak type Ia. The aortic neck anatomy, in particular the presence of thrombus, may influence the results of EVAR.
Objectives: To study the relationship between aneurysmal neck thrombus, type of endoprosthesis used and the development of endoleak Ia.
Materials/Methods: We made a retrospective analysis of the database of patients with AAA treated by EVAR at our institution between December 2001-2013. We reviewed all available preoperative CT scans (total of 164) and divided patients into two groups: with significant aortic neck thrombus (> 25% of the aortic neck circumference) versus no significant thrombus. We also studied the type of endoprosthesis (supra versus infra-renal fixation) used. Then, we evaluated the follow-up and the development of type Ia endoleak.
Results: Of the 164 patients, 38 had thrombus> 25% of the aortic circumference (versus 126 with thrombus <25%). 66 patients were treated with infra-renal fixation endoprothesis and 98 with supra-renal fixation endoprothesis. The mean follow-up time was 42.88 months (± 32.49). When we considered the type of endoprosthesis used we realised that 7 (7.14%) of the patients treated with supra-renal fixation endoprosthesis and 5 (7.57%) of those treated with infra-renal fixation endoprosthesis developed type Ia endoleak. Of the 38 patients with significant thrombus, 25 were treated with supra-renal fixation endoprostheses and 1 of them (4%) developed endoleak Ia; the remaining 13 were treated with infra-renal fixation endoprostheses and 2 of them (15.38%) developed endoleak Ia, however, this difference was not statistically significant (p = 0.265). Of the 126 patients with non-significant thrombus, 73 were treated with supra-renal fixation endoprostheses and 6 of them (8.22%) developed endoleak Ia; the remaining 53 were treated with infra-renal fixation stents and of these, 3 (5.66%) developed endoleak Ia.
Conclusions: The presence of a significant amount of thrombus in the aneurysmal neck does not seem to influence the development of type Ia endoleak. However, in patients with significant thrombus, although we did not obtain a statistically significant difference, we observed a higher percentage of endoleak type Ia in patients treated with infra-renal fixation endoprostheses. (15.38% versus 4%). It is necessary to maintain follow-up of these patients to draw conclusions in the future.