Abstract No. 159: Predictive factors for the development of type 2 endoleaks

Occurrence of a Type 2 endoleak (EL-2) is not uncommon and the etiology is not very well understood. The knowledge of predictive factors for EL-2 may help in clinical patient management. Our objective was to define some predictive factors for EL-2, based in the pre-treatment anatomic features of the AAA. Two hundred and eight patients underwent endovascular AAA repair and included in the study. Aortograms and CT scans were analyzed in retrospect to identify, characterize, compare and classify the EL-2 in two groups, transient and persistent. The transient EL-2, were the ones detected intra- or peri-operatively which spontaneously resolved within 6 months. The persistent EL-2 did not resolve spontaneously and lasted longer than 6 months. In 208 patients there were twenty-eight (13.5%) diagnosed EL-2. None of the patients with an EL-2 had less than four patent lumbar arteries at the time of EVAR (mean 5.2 vessels), with mean diameter of 2.3 mm. 45% of the patients underwent embolization of one of the internal iliac arteries. The mean number of feeding-vessels related to EL-2 was 4.3. The percentage of the thrombus occupation in the sac was 28%, and the IMA patency was 42%. There was no significant relationship between the amount of thrombus in the sac or IMA patency with the development of EL-2. Ten patients (35.7%) had transient EL-2 that resolved within one month. None of these cases had lumbar arteries larger than 2mm in diameter (mean 1.5mm). Eighteen (64.3%) of the 28 patients had persistent EL-2, the mean time to detection was 6,5 months, and he lumbar arteries had a mean diameter of 2.7mm. Persistent EL-2 developed in all cases with 4 patent lumbar arteries with at least one of them with 2 mm in diameter. None of the EL-2 shown in control angiograms without at least one lumbar artery greater than 2mm became persistent. The number of patent lumbar arteries (four or more p<0.001), and the hypogastric patency are importants predictive factors to the development of EL-2. The mean size of the lumbar arteries (>2mm) is a positive predictive factor to persistent EL-2 development (p<0.001).