L'eco color-doppler con contrasto nel follow-up del trattamento endoprotesico degli aneurismi dell'aorta addominale

Background. A prospective study was conducted in the course of the follow-up of patients given endovascular grafts as treatment for abdominal aorta aneurysms in order to compare the diagnostic accuracy of colour duplex scanning and CT scans both using contrast medium in the assessment of both postoperative leaks and variations in diameter. Methods. In November 1997 - June 1999, 29 patients (28 male and 1 female, mean age 69.5 years) were given transfemoral Aneurex aortic endografts. In 27 cases the problem was fusiform aneurysms of the subrenal aorta and in 2 cases anastomotic aortic pseudoaneurysms in patients who had previously been given an aortobifemoral bypass. The 27 AAA patients were classified on the basis of the Eurostar Protocol as Type A (4 patients), Type B (11), Type C (4), Type D (8) and Type E (0). In these cases the diameter range was 4.5-7 cm (mean 5.2 cm). The ASA system was used to classify the anaesthesiological risk in these patients (ASA II 8 patients, ASA III 13, ASA IV 8). Follow-up at 1, 6, 12 and 18 months involved an abdominal X-ray, an abdominal CT scan using contrast medium and an aortoiliac colour Duplex scan (ATL 3000 using a 4-2 MHz Convex probe) coronal and sagittal scans being performed in basal conditions and after infusions of Levovist ultrasound contrast medium. Results. All surgical procedures were successful, none requiring surgical conversion and with no deaths or major complications either in the immediate postoperative period or during follow-up. Persistent endoleak was noted in 3 patients (10.3%). They included 1 patient with a secondary (non-graft-related) distal leak, 1 with a primary (graft-related) distal leak and a secondary leak, 1 with a primary (graft-related) proximal leak between the aortic cuff and the main body of the graft which was corrected one month later by the insertion of a supplementary aortic cuff. In all cases the results of the colour duplex and CT scans (both using contrast medium) were identical though the former produced more information on blood flow. Among the 16 patients available to at least 6 months' follow-up 15 (93.7%) revealed a reduction in the diameter of the aneurysmatic sac (mean reduction 3.45 mm) on CT scans, while I case (6.3%) revealed an increased diameter (2 mm). Colour duplex was less reliable than CT in assessing aneurysm diameter. Conclusions. Preliminary results confirm the comparable efficacy of colour duplex and CT scanning using contrast medium in the identification of postoperative leaks following endovascular treatment of the aorta. The use of ultrasound contrast medium appears to enhance the sensitivity of that technique particularly in the identification of minor leaks, while colour duplex scans were particularly effective in identifying the source of leaks. On the other hand CT scanning was more effective in identifying reductions in aneurysm diameter (itself an indicator of the exclusion of the aneurysm). However all these results are preliminary and demand further study.