A 10-year-old boy with Marfan’s disease suffered an acute dissection of an aortic aneurysm. A dacron sleeve (extending from 3 cm above the sinuses of Valsalva to just distal to the left subclavian artery) was placed around the aorta. 2 years later the child succumbed to aortic dissection and rupture distal to the sleeve. Autopsy showed (1) complete healing of the earlier dissection, and (2) lack of aneurysmal progression within the sleeve. Although the sleeve had provided effective support to the diseased aorta, it did not have sufficient length and should have been extended to include the region of the first and second intercostal arteries. The use of an extensive dacron sleeve is potentially useful as treatment prior to dissection.