Type II endoleaks: diagnostic imaging, treatment and "prevention"

Aim. The endovascular treatment of infrarenal abdominal aortic aneurysms (AAA) represent at present a valid alternative to surgical treatment. Many trials have been carried out (EUROSTAR, EVAR) and they have shown effectiveness of this procedure at short and mid-term. Nevertheless another result that came out from these trials is the greater incidence of complications correlated to this treatment. These data need to be confirmed by sequential follow-up with the aim to compare and evaluate the long term results. Methods. From September 1998 to May 2009, 231 patients have been submitted to endovascular treatment of AAA. The choice for endovascular treatment has been carried out on the bases of these comorbidities: high surgical risk for related pathologies (73%); advanced age (12%); hostile abdomen (10.4%); emergency (2.6%); and patient preference (2%). The follow-up, carried for a period between 3 and 128 months for a mean of 65 months, has been performed at 1, 3 , 6 , 12 months from discharge and then annually. All patients were submitted to standard ultrasound investigation (UI) and by means of echocontrast and to CT-scan angiography (CTA) at 1 month from discharge and thereafter by means of the sole contrast-enhanced UI. When a complication related to the endograft was described at UI, a CTA was performed. Results. In our experience we observed 27 endoleaks (11.7%): 4 (1.7%) were classified as type I, 17 (7.3%) as type II, 2 (1%) as type III and 4 (1.7%) as type IV. Concerning type II endoleak, 11(64.7%) have been pointed out within 6 months from the procedure and the last 6 (35.3%) were recorded at 24-48 months. 10 endoleaks have not been treated since no modification of sac diameter was collected so as pulsation absence at UI, with a complete resolution in 4 cases; instead the remaining 7 cases (41.2%), 5 (29%) were submitted to an embolization procedure, in 1 case we performed a inferior mesenteric artery clipping by a laparoscopic approach and 1 patient has needed a surgical treatment after 48 months from the endograft deployment. Discussion. Endoleaks represent the most frequent adverse event (8-44%) in AAA endovascular treatment. Triphasic helical CT-scan is at present the reference standard for monitoring EVAR procedures. Despite its notable advantages ultrasonography has not yet achieved reference standard status in the EVAR follow-up because of yielded low diagnostic specificity and sensibility. Conclusion. Although triphasic helical CT-scan is at present the reference standard for monitoring EVAR procedures the contrast-enhanced ultrasound techniques can supply useful information without radiation exposure and with low cost, easy interpretation and performance.