W20 AJR:192, January 2009 placement of a graft in the diseased native aorta; the native aorta is left in situ and is su- tured around the graft (Fig. 2). Currently, the interposition technique is preferred over the inclusion technique because of the lower inci- dence of postoperative complications [1, 2]. In addition to the type of graft technique used, the surgical procedure varies depend- ing on the location and extent of aortic dis- ease and whether surgery will involve the coronary arteries, aortic valve, or aortic arch branch vessels. When reconstruction of the aortic root and aortic valve is required, the options are either graft repair of the ascend- ing aorta above the level of the coronary ar- teries with separate valve replacement [3] or a composite graft replacement—that is, an aortic graft directly attached to a mechanical valve [4]. With composite graft replacement, the coronary ostia are dissected with a rim of surrounding aorta (button technique) and reanastomosed individually to the composite graft (Fig. 3). The button technique of coro- nary anastomosis has superseded the Cabrol procedure. The latter involves use of a small single Dacron tube graft for anastomosis of both coronary arteries to the aortic graft [5]. Surgery for the treatment of diffuse tho- racic aortic disease is commonly performed via a two-stage operation known as the “ele- phant trunk procedure” [6, 7] (Fig. 4). The first stage of the operation is repair of the as- cending aorta and aortic arch and reconstruc- tion of the great vessels; the distal segment of the aortic graft material floats freely with- in the descending aorta. The second stage of the operation involves repair of the descend- ing aorta and fixation and extension of the first graft by placement of either an open MDCT Angiography After Open Thoracic Aortic Surgery: Pearls and Pitfalls Jenny K. Hoang 1 Santiago Martinez Lynne M. Hurwitz Hoang JK, Martinez S, Hurwitz LM 1 All authors: Department of Radiology, Division of Cardiothoracic Imaging, Duke University Medical Center, Box 3808, Erwin Rd., Durham, NC 27710. Address correspondence to J. K. Hoang (jenny.hoang@duke.edu). Vascular฀and฀Interventional฀Radiology฀•฀Pictorial฀Essay WEB This is a Web exclusive article. AJR 2009; 192:W20–W27 0361–803X/09/1921–20 © American Roentgen Ray Society E mergent and elective open tho- racic aortic surgery is performed for a wide variety of diseases in- cluding dissection, aneurysm, and pseudoaneurysm. Postoperative evalua- tion commonly uses CT angiography (CTA). In this article, we review open thoracic aortic surgeries and describe normal and abnormal postoperative CTA findings. Imaging Technique Imaging of the thoracic aorta can be ac- complished using various CT protocols de- pending on the specific question to be an- swered by the study. For routine postoperative assessment of the thoracic aorta, unenhanced and contrast-enhanced CTA images allow as- sessment of the graft and intraluminal and extraluminal abnormalities. Review of the data set using a workstation for 3D recon- structions is required to completely and accu- rately assess aortic size and for complications of the surgery. Cardiac-gated CTA techniques may be of benefit when complications in- volving the aortic valve or aortic sinus are suspected or may be used to evaluate patency of coronary bypass grafts or concomitant disease affecting native coronary arteries. Types of Open Aortic Surgery Open surgical repair of the thoracic aorta consists of two basic surgical techniques: in- terposition or inclusion technique for graft placement. The interposition technique in- volves resection of the diseased segment of aorta and placement of a graft that is com- posed of synthetic polyester textile fibers (Dacron, DuPont) (Fig. 1). In contrast, the in- clusion technique entails an aortotomy and Keywords: aorta, aortic dissection, aortic grafts, aortic surgery, CT angiography DOI:10.2214/AJR.08.1364 Received June 7, 2008; accepted after revision July 24, 2008. OBJECTIVE. The purpose of this article is to review open thoracic aortic surgical tech- niques and to describe the range of postoperative findings on CT angiography (CTA). CONCLUSION. An understanding of surgical thoracic aortic procedures will allow ap- propriate differentiation of normal from abnormal CTA findings on postoperative imaging. Hoang et al. CTA After Open Thoracic Aortic Surgery Vascular and Interventional Radiology Pictorial Essay Downloaded from www.ajronline.org by 52.73.204.196 on 05/17/22 from IP address 52.73.204.196. Copyright ARRS. For personal use only; all rights reserved