Surgical and Endovascular Repair of Aortic Coarctation: Normal Findings and Appearance of Complications on CT Angiography and MR Angiography

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1 T and MRI ngiography of ortic oarctation Repair Vascular Imaging Pictorial Essay Downloaded from by on 04/09/18 from IP address opyright RRS. For personal use only; all rights reserved M E D E N T U R I L I M G I N G Ming-hen Paul Shih 1,2 shok Tholpady 3 hristopher M. Kramer 1,4 Malcolm K. Sydnor 1,5 Klaus D. Hagspiel 1 JR 2006; 187:W302 W X/06/1873 W302 merican Roentgen Ray Society Y O F Shih M-P, Tholpady, Kramer M, Sydnor MK, Hagspiel KD Keywords: aortic coarctation, cardiovascular imaging, T angiography, MR angiography, vascular imaging DOI: /JR Received March 10, 2005; accepted after revision June 7, Division of Noninvasive ardiovascular Imaging, Department of Radiology, University of Virginia Health System, 1215 Lee St., PO ox , harlottesville, V ddress correspondence to K. D. Hagspiel (kdh2n@virginia.edu). 2 Department of Medical Imaging, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan. 3 University of Virginia Medical School, harlottesville, V. 4 Division of ardiology, Department of Medicine, University of Virginia Health System, harlottesville, V. 5 Present address: Department of Radiology, Virginia ommonwealth University Health System, Richmond, V. WE This is a Web exclusive article. Surgical and Endovascular Repair of ortic oarctation: Normal Findings and ppearance of omplications on T ngiography and MR ngiography OJETIVE. variety of treatment options exist for aortic coarctation, both surgical and catheter-based. Knowledge of the normal radiologic appearance of these, as well as their typical complications, is essential for interpretation of T and MR angiographic studies in these patients. ONLUSION. T and MR angiography are noninvasive techniques that are well suited to follow patients after coarctation repair. ortic coarctation is a common cardiovascular lesion accounting for 5 7% of all congenital heart disease [1]. It is defined as a discrete stenosis in the proximal descending thoracic aorta, first described by Morgagni at autopsy in 1760 [2]. oarctation is twice as common in males as in females, and is known to occur in conjunction with a variety of conditions, including Turner s syndrome, Shone syndrome, ventricular septal defect, bicuspid aortic valve, and aneurysms of the circle of Willis [3]. Without appropriate treatment, complications are common and include aortic dissection, infective endocarditis, severe aortic insufficiency, hypertension, coronary artery disease, and intracranial hemorrhage [4]. Up to 90% of patients with uncorrected coarctation die by the age of 60 years. number of surgical and endovascular treatment options are available. Surgical treatment is preferred in neonates and infants [5, 6]. In 1982, transcatheter balloon dilation was first described as a potential alternative to surgery [7]. nother successful alternative to end-to-end anastomosis as the primary treatment is the placement of balloonexpandable endovascular stents [8]. Stents are also placed in the setting of failed or complicated percutaneous transluminal angioplasty. Endovascular treatment is generally preferred in older children and adults. Despite more than five decades of experience with many treatment techniques of this seemingly simple lesion, there continues to be considerable discussion of what are the best therapeutic approaches for both pediatric and adult patients. fter repair of aortic coarctation, close follow-up of patients is recommended because surgery is in many ways not curative. Late complications, as a consequence of the surgery itself or the systemic arteriopathy, are not rare. Irrespective of the success of the repair, hypertension frequently develops and is a major contributor to long-term cardiovascular morbidity, although early surgical intervention may reduce the risk of developing late hypertension and other cardiovascular sequelae. In one large surgical series, the most common causes of death in patients with successful coarctation repair were coronary artery disease (37%), congestive heart failure (9%), and complications of reoperation (7%) [4]. The most frequent indications for reoperation include recurrent coarctation, ascending aortic aneurysm, valvular heart disease, and pseudoaneurysm formation [5]. Therefore, the radiologist is likely to be confronted with both the normal and complicated appearances that result from a large variety of treatment techniques. In this pictorial essay, we review the normal findings and the appearance of complications after coarctation repair. Noninvasive Imaging ecause of its ability to provide both anatomic and hemodynamic information, angiography remains the gold standard for the pretherapeutic workup of patients with coarctation. However, the noninvasive cross- W302 JR:187, September 2006

2 T and MRI ngiography of ortic oarctation Repair Downloaded from by on 04/09/18 from IP address opyright RRS. For personal use only; all rights reserved Fig. 1 Surgical techniques for repair of aortic coarctation. Top row shows end-to-end anastomosis. Segment containing coarctation is resected, and proximal and distal aortic segments are apposed directly end to end. Second row shows subclavian flap procedure. Distal subclavian artery is divided, and flap of proximal portion of vessel is used to widen segment with coarctation. Third row shows patch aortoplasty. Elliptic woven Dacron (DuPont) patch is inserted to expand diameter of lumen. Fourth row shows interposition grafting. If resected segment of coarctation is too long to allow end-to-end anastomosis, interposition graft is inserted, creating proximal and distal anastomoses. ottom row shows extraanatomic bypass graft. Extraanatomic ascending aorta to descending thoracic aorta bypass grafting is created through median sternotomy and posterior pericardial approach. sectional imaging techniques, including echocardiography, T, and MRI, are the primary techniques for posttreatment evaluation and surveillance. The preferred techniques for patient follow-up are MDT angiography and MRI, including contrastenhanced MR angiography, which are the focus of this pictorial essay. The decision as to what technique to use largely depends on the equipment and expertise available at the institution. Ungated MDT angiography is generally sufficient for cases where only the aorta and its branches are of interest. dditionally, EGgated T angiography allows evaluation of the aortic valve. Similarly, contrast-enhanced MR angiography is, for the most part, sufficient for evaluation of the aorta and its branches, whereas cine MRI and phase-contrast MRI allow assessment of the hemodynamic significance of the coarctation, as well as cardiac and valvular function. Maximum-intensity-projection (MIP) and multiplanar reconstructions are preferable for contrast-enhanced MR angiography, whereas volume-rendered and multiplanar reconstructions are better for T angiography data display. Surgical Repair of oarctation The first surgical repair of aortic coarctation was performed by rafoord in 1944 [5] (Fig. 1). Since then three major types of surgical techniques for coarctations have evolved: prosthetic patch aortoplasty, subclavian flap aortoplasty, and extended endto-end anastomosis (Figs. 2 and 3). Less frequently used techniques include insertion of a graft in situ (Figs. 4 and 5) or in an extraanatomic location. Figure 1 shows all currently used techniques. omplications associated with all surgical techniques, but especially with pros- JR:187, September 2006 W303

3 Downloaded from by on 04/09/18 from IP address opyright RRS. For personal use only; all rights reserved Fig year-old man after operative repair of aortic coarctation using end-to-end anastomosis technique in early childhood. Oblique sagittal multiplanar reformatted T angiogram shows normal postoperative appearance of repaired coarctation; arrowheads point to site of anastomosis. Note relatively distal origin of left subclavian artery close to repair (arrow). Fig year-old man who underwent interposition graft repair of aortic coarctation in early infancy. Oblique sagittal maximum-intensity-projection 3D contrast-enhanced MR angiography shows postoperative condition with residual hypoplastic arch (single arrowhead) and coarctation treated with interposition graft. rrows show proximal and distal anastomoses. Note ascending aortic ectasia (double arrowhead). Fig. 3 3-year-old girl after surgical repair using end-to-end anastomosis technique for aortic coarctation. Oblique sagittal maximum-intensity-projection 3D contrastenhanced MR angiography shows normal end-to-end anastomosis features (arrowheads). Fig. 5 3-week-old girl born with preductal coarctation of aorta and patent ductus arteriosus (PD) treated with pulmonary homograft repair of coarctation and ligation of PD., Maximum-intensity-projection (MIP) oblique sagittal MDT angiography shows aortic coarctation (arrow) and PD (arrowhead). (Fig. 5 continues on next page) W304 JR:187, September 2006

4 T and MRI ngiography of ortic oarctation Repair Downloaded from by on 04/09/18 from IP address opyright RRS. For personal use only; all rights reserved Fig. 5 (continued) 3-week-old girl born with preductal coarctation of aorta and patent ductus arteriosus (PD) treated with pulmonary homograft repair of coarctation and ligation of PD. and, Postsurgical MIP () and thin-slab MIP () contrast-enhanced MR angiography show appearance after successful ligation of PD and proximal and distal anastomoses of pulmonary homograft (arrows). Note hypoplasia of right lung and right pulmonary artery with extralobar sequestration (star, ), with afferent blood supply from infradiaphragmatic abdominal aorta (single arrowhead, ) and venous drainage to suprahepatic inferior vena cava (double arrowhead, ). lso note aberrant right subclavian artery origin. Fig year-old girl after subclavian flap surgical repair 11 years earlier. Maximum-intensity-projection MR angiography shows pseudoaneurysm formation (star) at operative repair site. Note postsurgical occlusion of proximal left subclavian artery (arrow) whose distal portion is reconstituted by way of vertebral artery (arrowhead). Fig year-old man who underwent repair of aortic coarctation 20 years earlier. Maximum-intensityprojection 3D contrast-enhanced MR angiography shows normal appearance of extraanatomic bypass graft from ascending to descending thoracic aorta (arrows). ortic arch distal to left common carotid artery and proximal descending thoracic aorta is surgically absent. thetic patch aortoplasty and subclavian flap aortoplasty, include aneurysm formation and high recoarctation rate, respectively. The low complication rate of end-to-end anastomosis makes it the most popular surgical technique [6]. In subclavian flap aortoplasty, the left subclavian artery is ligated at the first branch. n incision is made along the coarctation and the subclavian artery to create a flap. The posterior wall of the coarctation is then resected, and the subclavian flap is transposed to enlarge the stenotic area. This technique is thought to allow growth of the anastomosis and thus is used in children. However, it is not recommended in adults because of concern for reduced arterial supply to the arm (Fig. 6). To decrease potential surgical complications in adult patients with complex forms of aortic coarctation repair, techniques of extraanatomic ascending aorta to descending thoracic aorta bypass grafting have been described (Fig. 7). Endovascular Treatment Options Transcatheter balloon angioplasty for both native and recurrent coarctation is increasingly performed, and its indications are expanding. omplications of this treatment technique JR:187, September 2006 W305

5 Downloaded from by on 04/09/18 from IP address opyright RRS. For personal use only; all rights reserved Fig year-old man with medical history of familial non-williams supravalvular aortic stenosis and coarctation who had patch repair of coarctation at age of 7 years. He returns now for endovascular treatment of aortic recoarctation. and, Oblique sagittal maximum-intensity-projection contrast-enhanced MR angiography () and right posterior oblique arch aortogram (), done for persistent hypertension, show recoarctation of aorta (arrows) at site of patch repair with associated left carotid and left subclavian artery orifice stenoses (arrowheads). 40-mm gradient is present across lesion.6 E, Follow-up aortogram after stent placement (), oblique sagittal multiplanar reconstruction (D), and volume-rendered MDT angiogram (E) show complete resolution of stenosis after balloon dilatation and stent placement (arrows) in region of coarctation. No pressure gradient is seen at end of procedure. (Fig. 8 continues on next page) D W306 JR:187, September 2006

6 T and MRI ngiography of ortic oarctation Repair Downloaded from by on 04/09/18 from IP address opyright RRS. For personal use only; all rights reserved E Fig. 8 (continued) 36-year-old man with medical history of familial non-williams supravalvular aortic stenosis and coarctation who had patch repair of coarctation at age of 7 years. He returns now for endovascular treatment of aortic recoarctation. E, Follow-up aortogram after stent placement (), oblique sagittal multiplanar reconstruction (D), and volume-rendered MDT angiogram (E) show complete resolution of stenosis after balloon dilatation and stent placement (arrows) in region of coarctation. No pressure gradient is seen at end of procedure. Fig. 9 2-day-old girl with critical coarctation of aorta at birth complicated by thrombosis of distal arch and proximal descending thoracic aorta underwent aortotomy, thrombectomy, and coarctation repair with pulmonary homograft insertion. This was complicated by development of membranous anastomotic stenosis, which was treated with percutaneous transluminal angioplasty. Since then, she has undergone repeated balloon angioplasties for residual obstruction., Maximum-intensity-projection (MIP) contrast-enhanced MR angiography shows initial appearance of thrombosed arch (arrow) distal to left common carotid artery and proximal descending thoracic aorta (arrowhead)., MIP contrast-enhanced MR angiography after surgical revision and percutaneous transluminal angioplasty for recoarctation shows membranous stenosis (arrow)., Oblique sagittal cine MR angiography shows jet caused by membrane proving its hemodynamic significance (arrowhead). JR:187, September 2006 W307

7 Downloaded from by on 04/09/18 from IP address opyright RRS. For personal use only; all rights reserved include recurrent stenosis, dissection, aneurysm formation, and, rarely, rupture. Recurrence is a frequent problem, especially in infants and young children. alloon dilation may be viewed as a palliative or staged procedure. Since the Fig year-old woman who underwent patch aortoplasty repair of aortic coarctation and closure of patent ductus arteriosus (PD) that occurred at age 3 years., Three-dimensional contrast-enhanced MR angiography maximum intensity projection shows trilobed pseudoaneurysms of proximal descending aorta (arrowhead) just distal to left subclavian artery (arrow) and between origins of left carotid and subclavian arteries., xial multiplanar reconstruction of contrastenhanced MR angiography shows two of three aneurysms (arrows) protruding from each side of aortic arch (star). Fig year-old man with history of aortic coarctation operated on at age 14 years with placement of a Dacron (DuPont) patch. and, Right posterior oblique digital subtraction angiogram () and maximum-intensity-projection contrast-enhanced MR angiogram () show pseudoaneurysm (arrows) in region of aortic isthmus where coarctation was repaired. mid 1980s, endovascular stents have become an integral component for the treatment of lesions with recoil after primary balloon angioplasty. ortic stent placement is feasible in both patients with coarctation and those with recoarctation (Fig. 8). The use of endovascular stents in children is controverial. oncerns about the feasibility of redilation in growing children generally limits the use of stents to adults and older adolescents. W308 JR:187, September 2006

8 T and MRI ngiography of ortic oarctation Repair Downloaded from by on 04/09/18 from IP address opyright RRS. For personal use only; all rights reserved Fig year-old man after repair of transposition of great vessels that occurred as infant and patch repair of aortic coarctation that occurred at age 6 years. Maximum-intensityprojection contrastenhanced MR angiography shows large aneurysm in proximal descending thoracic aorta. Patient subsequently underwent uneventful surgical tube graft repair. Fig year-old man with aortic coarctation patch repair that occurred at age 6 years presents with abrupt onset of left chest pain. and, Maximum-intensity-projection () and volume-rendered () MDT angiograms show acute rupture of descending thoracic aortic pseudoaneurysm () (star, ) at site of previously repaired aortic coarctation., xial MDT source image shows site of leak (arrowhead) and hemothorax. JR:187, September 2006 W309

9 Downloaded from by on 04/09/18 from IP address opyright RRS. For personal use only; all rights reserved omplications of Treatment Restenosis or Recoarctation Recoarctation is considered to be present whenever the pressure gradient across the anastomotic stenosis is higher than 20 mm Hg at rest and occurs after both surgical and endovascular treatment. Residual coarctation is defined by the presence of a gradient in the early postoperative period. Recurrent coarctation is inferred when there is a gradient at later stages. Fig year-old woman with history of three previous aortic coarctation repairs, most recent of which was 8 years earlier and consisted of interposition Dacron (DuPont) graft. She presented emergently with massive hemoptysis., Oblique sagittal volume-rendered T angiography reveals large pseudoaneurysm at proximal descending thoracic aorta., xial contrast-enhanced T image shows hemomediastinum, hemothorax, and site of leak (arrow)., Postoperative maximum-intensity-projection T angiography reveals extraanatomic Dacron Hemashield (Meadox Medicals) bypass (arrowheads) from ascending aorta to intraabdominal supraceliac aorta and surgical occlusion of arch distal to left common carotid artery and proximal descending thoracic aorta. lso note extraanatomic graft from aortic graft to left subclavian artery (arrow). Occasionally, this stenosis can have the appearance of webs, which can make them hard to visualize on T angiography and contrastenhanced MR, but cine MRI usually detects the jet caused by the stenosis (Fig. 9). W310 JR:187, September 2006

10 T and MRI ngiography of ortic oarctation Repair Downloaded from by on 04/09/18 from IP address opyright RRS. For personal use only; all rights reserved Fig year-old woman with long history of hypertension and recent diagnosis of congenital coarctation of aorta presented for balloon angioplasty of coarctation. ngioplasty was performed with near-complete resolution of initial pressure gradient of 37 mm Hg, but was complicated by type aortic dissection., Oblique sagittal maximum-intensity-projection (MIP) contrast-enhanced MR angiogram shows type dissection (arrowheads), which extends from just below coarctation (arrow) to level of celiac axis. She subsequently underwent stent placement. and, xial () and sagittal () (MIP) T angiograms images performed 6 years later show descending thoracic aortic stent in true lumen (arrowheads) with stable descending thoracic aortic and abdominal aortic dissection. Dissecting membrane (arrows, ) terminates between celiac artery and superior mesenteric artery. JR:187, September 2006 W311

11 Downloaded from by on 04/09/18 from IP address opyright RRS. For personal use only; all rights reserved neurysm Formation lthough various definitions exist for the presence of an aneurysm, most investigators agree that it constitutes a wall contour deformity whose diameter is 1.5 times that of the aorta at the level of the diaphragm. neurysm formation occurs after both surgical and endovascular treatment (Figs ). neurysm Rupture neurysm rupture has been described after both surgical and endovascular repair. This condition, with few exceptions, is fatal (Figs. 13 and 14). ortic Rupture oth percutaneous transluminal angioplasty and stent placement can lead to aortic rupture. The risk of death from balloon angioplasty for native coarctation is estimated at 0.7% from the Valvuloplasty and ngioplasty of ongenital nomalies Registry. Dissection Dissection of the aorta is primarily a complication of percutaneous transluminal angioplasty and its treatment is often stent placement to exclude the false lumen and provide patency of the true lumen (Fig. 15). ortic Thrombosis ortic thrombosis has also been described after surgical and endovascular treatment; it generally requires additional surgery (Fig. 9). onclusion Familiarity with the appearance of the aorta after both surgical and endovascular repair and the respective complications of both procedures is necessary to provide accurate imaging interpretation and to direct appropriate patient care. oth T angiography and contrast-enhanced MR angiography allow assessment of the pertinent vasculature in great detail, whereas MRI is superior if functional information about hemodynamic significance and cardiac function is needed. References 1. Jenkins NP, Ward. oarctation of the aorta: natural history and outcome after surgical treatment. Q J Med 1999; 92: lexander. The seats and causes of diseases investigated by anatomy. London, UK: Millar & adell, ttenhofer Jost H, Schaff HV, onnolly HM, et al. Spectrum of reoperations after repair of aortic coarctation: importance of an individualized approach because of coexistent cardiovascular disease. Mayo lin Proc 2002; 77: rickner ME, Hillis LD, Lange R. ongenital heart disease in adults: first of two parts. N Engl J Med 2000; 342: rafoord, Nylin G. ongenital coarctation of the aorta and its surgical treatment. J Thorac Surg 1945; 14: Manganas, Iliopoulos J, hard R, et al. Reoperation and coarctation of the aorta: the need for lifelong surveillance. nn Thorac Surg 2001; 72: Singer MI, Rowen M, Dorsey TJ. Transluminal aortic balloon angioplasty for coarctation of the aorta in the newborn. m Heart J 1982; 103: Ebheid MR, Prieto LR, Latson L. Use of balloonexpandable stents for coarctation of aorta: initial results and intermediate-term follow-up. J m oll ardiol 1997; 30: W312 JR:187, September 2006