Ulcerlike Projections Developing in Noncommunicating Aortic Dissections: CT Findings and Natural History

OBJECTIVE. Aortic ulcerlike projections are focal, contrast-filled outpouchings projecting from the aortic lumen. Our aim was to document the CT findings and natural history of ulcerlike projections developing in patients with preexisting noncommunicating aortic dissection, including intramural hematoma or false lumen thrombosis. MATERIALS AND METHODS. By searching the radiology information system, we found 38 ulcerlike projections arising in an underlying noncommunicating aortic dissection that were identified at CT in 24 patients. Clinical factors were determined from patient records. CT scans were reviewed to determine aortic pathology type and appearance time of ulcerlike projections and to measure the diameters of the aorta and ulcerlike projections for comparison over time. Complications were defined as an increase of at least 20% in the diameters of the ulcerlike projections or aorta, the need for surgical repair, or both. Comparisons of ulcerlike projections with and without complications were performed using various statistical tests. RESULTS. The underlying aortic disease of the 38 ulcerlike projections was intramural hematoma in 26, false lumen thrombosis in nine, and unknown in three. The mean time of ulcerlike projection appearance was 2.4 months (SD, 1.8) for intramural hematoma and 19.3 months (SD, 18.1) for false lumen thrombosis. Nine of the 28 ulcerlike projections with follow-up scans showed stability, size decrease, or resolution; 10 increased in size; and nine were incorporated into ail expanded aortic lumen. Four of 36 ulcerlike projections with imaging or clinical follow-up (or both) required surgical repair. The only clinical or imaging feature significantly associated with the development of complications was false lumen thrombosis (p = 0.04). CONCLUSION. Ulcerlike projections forming in noncommunicating dissections may enlarge over time, although they rarely require surgical repair. Given the potential for critical complications, these lesions should be followed with serial CT scans.