Giant Abdominal Aortic Aneurysm
An 88-year-old man with a history of smoking, hypertension, and hyperlipidemia was admitted for assessment of a painless abdominal mass. Five years earlier, he had noticed a painless, slowly enlarging abdominal mass; since he was otherwise asymptomatic, he did not seek medical attention. Physical examination revealed a pulsatile, well-defined, nontender abdominal mass (Movie I in the online-only Data Supplement), and a mild bruit was heard on auscultation. Peripheral pulses were palpable in both lower limbs. Ultrasonography of the abdomen showed a giant aortic aneurysm with a large mural thrombus (Figure 1A) and the central sector detected turbulent color flow with duplex image (Movie II in the online-only Data Supplement). Abdominal computed tomography (CT) with intravenous administration of contrast material revealed a large infrarenal aortic aneurysm measuring 11×11 cm with a large mural thrombus (Figure 1B, black arrow) compressing the inferior vena cava (white arrow) and a short neck (Figure 1C, arrow). It extended to the aortic bifurcation and proximal right common iliac artery; at this level, the aneurysm was 4×4 cm (Figure 1D, arrow).
The patient underwent a successful open surgical repair (Figure 2A) with placement of an aortoiliac bifurcated Dacron graft (Vasuctek, Terumo Cardio-Vascular Systems Corp, Ann Arbor, Mich). A postoperative CT scan demonstrated complete sealing of the aneurysm, and no endoleak was detected (Figure 2B). A CT scan with 3-dimensional reconstruction was useful for confirming patency of the branched section of the graft (Figure 2C). Power Doppler ultrasound follow-up at 1 month (Figure 2D) showed an aortic graft with normal flow. The patient recovered uneventfully and at present continues to do well (Figure 3).
Abdominal aortic aneurysms (AAAs) occur in up to 9% of adults >65 years of age, and of those, 96% are <6 cm.1 Furthermore, men are 10 times more likely than women to have an AAA that is ≥4 cm. Aneurysm size is the most important factor related to likelihood of rupture, and the risk increases substantially in large aneurysms. The annual rupture risk for AAAs >8 cm is 30% to 50%.2 Giant AAAs are seen infrequently, and only a few cases of giant AAAs with a maximum diameter >11 cm have been reported in the English literature.
The repair of these giant aneurysms presents a challenge during surgery because aortic clamping can be difficult owing to their size. All cases were managed with open surgical repair because anatomic factors prevented an endovascular approach. The huge size of the aneurysm, its short neck, and the dislodgement of abdominal organs, which may be densely adhered to its surface with fistula formation, make surgery of this entity challenging. Open repair of giant AAAs is often the only available treatment, although not always with good results.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/cgi/content/full/122/3/e392/DC1.
Lederle FA, Johnson GR, Wilson SE, Chute EP, Hye RJ, Makaroun MS, Barone GW, Bandyk D, Moneta GL, Makhoul RG. The aneurysm detection and management study screening program: validation cohort and final results: Aneurysm Detection and Management Veterans Affairs Cooperative Study Investigators. Arch Intern Med. 2000; 160: 1425–1430.
Brewster DC, Cronenwett JL, Hallett JW, Johnston KW, Krupski WC, Matsumura JS. Guidelines for the treatment of abdominal aortic aneurysms: report of a subcommittee of the Joint Council of the American Association for Vascular Surgery and Society for Vascular Surgery. J Vasc Surg. 2003; 37: 1106–1117.