Immediate and two-year outcomes after EVAR in "on-label" and "off-label" neck anatomies using different commercially available devices. analysis of the experience of two Italian vascular centers.
BACKGROUND
Endovascular aneurysm repair (EVAR) has fast become the therapeutic strategy of choice for abdominal aortic aneurysms (AAAs). Nowadays, the most important limit to the effectiveness of this technique is represented by complex anatomical situations, especially regarding the morphology of the proximal sealing zone. The aim of this study was to evaluate the 2-year outcome of unselected, real-world patients with "off-label" (off-L) proximal necks treated in 2 high-volume Italian vascular centers.


METHODS
A double-center study was conducted on a prospectively compiled computerized database between January 2010 and December 2011. One hundred and ninety-six consecutive elective surgery patients were analyzed and divided into 2 groups ("on-label" [on-L] and "off-L" necks) on the basis of their aortic neck anatomy. The neck was classified as an "off-L neck" in the presence of: (1) a noncylindrical neck, (2) an angulated neck, (3) a short neck, and (4) an enlarged neck. The end points were 30-day and 2-year technical and clinical success, evaluated in terms of freedom from reintervention and death.


RESULTS
One hundred and thirty-three elective patients were treated by standard EVAR in the presence of an "off-L" proximal neck anatomy. Technical success was achieved in all cases in both groups. Six (9.5%) unplanned adjunctive procedures were necessary in the on-L group and 16 (12%) in the off-L group (P = ns). Perioperative endoleaks, reinterventions, stent-graft migration rates, and AAA-related deaths were null. A multivariate analysis was performed to evaluate the subgroups of patients with 2 or > 2 anatomic factors that indicate a challenging neck. In patients with 2 such factors, a significant difference was observed in terms of intraoperative adjunctive procedures, intraoperative endoleaks, and all-cause mortality: 26.7% vs. 9.9% (P = 0.048), 6.7% vs. 0.5% (P = 0.023), and 13.3% vs. 1.1% (P = 0.0012), respectively. The same differences became increasingly evident when analyzing patients with > 2 criteria: 50% vs. 10% (P = 0.0022), 16.7% vs. 0.5% (P < 0.001), and 16.7% vs. 1.0% (P = 0.01). No AAA-related deaths or AAA ruptures were reported in either group at the end of the 2-year follow-up. High-flow endoleaks, stent-graft migration, and, consequently, reintervention were more frequent in the off-L group, but none of these parameters reached statistical significance.


CONCLUSIONS
Our experience seems to show that the off-L use of EVAR could be considered effective for the treatment of patients unfit for open surgery. In patients with more than one anatomical proximal neck feature contraindicating open surgery, the rate of immediate complications and reinterventions was higher, but this did not affect the clinical benefit and success at 2-year follow-up.