Primary Absence of Type II Endoleak is A Positive Prognostic Factor against the Risk of Late Conversion of EVAR for AAA

Introduction: The aim of this study is to analyze 12 late conversion to open surgery after Endovascular Repair of Abdominal Aortic Aneurysms (EVAR) while comparing the follow up of these cases to that of the definitely successful procedures (absence of surgical conversion, type I or III endoleaks, or presence of type II endoleaks without any aneurysmal sac enlargement) . Methods: From a series of over 300 EVAR procedures performed at our department we have selected 215 cases with a follow up ≥ 6 month and primary technical success (successful deployment of the devices and discharge of patients without neither type I nor III endoleaks). Based on the final data recorded at the end of the follow up (mean+ IQR: 38.16 months + 41), these cases were divided into three groups: group 1, with 12 cases (5.6%) which needed surgical conversion in a later stage (5 to 55 months from EVAR); group 2, with 39 cases (18.1%) with type II endoleaks without aneurysmal sac enlargement; group 3, with 164 cases (76.5%) without endoleaks. The groups were compared in relation to the following parameters: a) personal data and common atherogenic risk factor, b) diameter of the aneurysm, c) kind of the proximal fixation of the endograft (suprarenal or infrarenal), d) presence of endoleaks at the first postoperative check. We have compared the data from the three groups and we have analyzed them with chi-square test (Χ2). Results: Personal data and common atherogenic risk factor have proved no significant difference among the three groups. The incidence of the other three parameters of group 1 was compared with the incidence of these in groups 2 and 3: the mean pre-operative diameter of the aneurysm results 51 mm in group 1, 54 mm in group 2 and 55 mm in group 3 (not significant); suprarenal fixation of the prosthesis accounts for 50% in group 1, 51% in group 2 and 60% in group 3 (not significant); presence of type II endoleak at the first post-operative check was 41.6% in group 1, 56.4% in group 2 (not significant) and 9.7% in group 3 (p<0.001, compared to groups 1 and 2). Conclusion: In the EVAR procedures with primary technical success, the absence of type II endoleak at the first post-operative check represents a favorable prognostic factor against the risk of late conversion to open repair. Personal data, common atherogenic risk factor, diameter of the aneurysm and fixing type of the prosthesis don’t seem to influence the onset of this complication.