Ann Thorac Surg 2008;85:636-638. doi:10.1016/j.athoracsur.2007.08.069
© 2008 The Society of Thoracic Surgeons
Case Reports
Endovascular Treatment of Rapidly Expanding Thoracoabdominal Aortic Aneurysm After Surgical Repair of Acute Type A Dissection
Sahin Senay, MDa,*,
Cem Alhan, MDa,
Hasan Karabulut, MDa,
Fevzi Toraman, MDa,
Huseyin Cagil, MDb
a Department of Cardiovascular Surgery, Acibadem Kadikoy Hospital, Istanbul, Turkey
b Department of Radiology, Acibadem Kadikoy Hospital, Istanbul, Turkey
Accepted for publication August 27, 2007.
* Address correspondence to Dr Senay, Ozlem Sitesi B Blok D, 25 Kosuyolu-Uskudar, Istanbul, 81100, Turkey (Email: sahinsenay{at}gmail.com).
 |
Abstract
|
|---|
We report the successful endovascular treatment of a rapidly expanding thoracoabdominal aortic aneurysm after surgical treatment for acute type A dissection in a 53-year-old man who had previously undergone replacement of the aortic valve and ascending aorta with a composite graft and coronary bypass.
|
Introduction
|
|---|
Acute type A aortic dissection may involve ascending, arcus, and thoracoabdominal aorta. It may by complicated by aortic valvular insufficiency, rupture, aneurysm formation, and visceral malperfusion. Emergency surgical procedure aims to repair the proximal aorta and restore the aortic valvular competency and systemic perfusion as well as to obliterate the false lumen blood flow and prevent rupture, myocardial infarction, stroke, and death. However, the distal aortic pathology remains, and it carries the risk of aneurysm formation and rupture of thoracoabdominal aorta [1]. Conventional surgical treatment of these secondary pathologies involves complex procedures with an operative mortality of 10% to 20% [2, 3]. An endovascular technique is an effective treatment option for primary thoracoabdominal aortic pathologies, with lower mortality and morbidity rate. However, the aneurysm formation with a dissecting segment is a more complex pathology, and endovascular treatment option is not the choice in most cases [2]. We report successful endovascular treatment of rapidly expanding thoracoabdominal aortic aneurysm after surgical treatment for acute type A dissection in a patient who had previously undergone replacement of aortic valve and ascending aorta with a composite graft and coronary bypass.
A 53-year-old man was admitted to our center after an evaluation for new-onset chest pain 1 year earlier. The computed tomography (CT) scan revealed a type A aortic dissection with an intimal flap arising above the right coronary artery and reaching to the abdominal aorta. Maximal diameter was 55 mm for ascending aorta and 36 mm for descending aorta (Figs 1A, B). An infrarenal aortic aneurysm with a maximal diameter of 63 mm and bilateral aneurysmatic dilation of femoral arteries (with a maximal diameter of 29 mm on the right and 30 mm on the left side) were also detected (Figs 1B, C). Echocardiographic examination revealed severe aortic insufficiency. Emergent operation was planned. Replacement of aortic valve and ascending aorta with composite graft (23-mm Medtronic valved conduit [Medtronic Inc, Santa Rosa, CA]) and triple coronary bypass grafting were performed. The patient recovered in the intensive care unit and was extubated at postoperative hour 3. He was discharged on the fourth day after the procedure. He had refused to be treated for the aneurysmatic segments of the aorta. No complaints had been determined on regular follow-up. Control CT scan at the first year revealed progressive dilatation of the thoracoabdominal aorta (Figs 2A-E). More than 10-mm expansion of the descending aorta and 22-mm expansion of the abdominal aorta were detected. Urgent operation was planned. Conventional repair was considered to be a very high risk option, and the patient was presented with the choice of stent-graft placement. The patient agreed to undergo this procedure, written informed consent was obtained, and endovascular treatment was organized. At the interventional cardiology theater, under general anesthesia, the delivery system was advanced through the thoracic aorta through the right femoral artery. The proximal end of the graft (44 mm Medtronic [Medtronic Inc], AF3416C170AX) was placed distally to the left subclavian artery. Completion angiography confirmed total exclusion of the aneurysm. Simultaneous aortobifemoral stenting of the abdominal segment (34/16 mm Medtronic [Medtronic Inc], TF4444C100X, 18/16 mm IW1416C105AX) and bilateral stenting of the iliofemoral segment (16/14 mm Medtronic, IXW1814C75AX) were also performed (Fig 2F). The patient’s initial recovery was uneventful. Control CT scan on the third postoperative day confirmed patent stents. The patient was discharged on the third day after the procedure. No complaints have been determined on regular follow-up at the third month.
View larger version (41K):
[in this window]
[in a new window]
|
Fig 1. (A-C) Type A aortic dissection with an intimal flap arising above the right coronary artery and reaching to the abdominal aorta. The infrarenal aorta and femoral arteries are dilated.
|
|
View larger version (79K):
[in this window]
[in a new window]
|
Fig 2. (A-C) Control computed tomography scan at the first year reveals progressive dilatation of the thoracoabdominal aorta. (D, E) The contrast difference points that the right renal artery is perfused through the true lumen. (F) Control computed tomography scan at the postoperative third day of endovascular procedure. The false lumen is obliterated. The renal arteries are intact.
|
|
|
Comment
|
|---|
Endovascular repair of primary thoracoabdominal aortic aneurysms is well described. However, the aneurysms with chronic dissections have more complex morphology, and conventional surgical treatment is preferred frequently [2]. But the endovascular techniques may also be feasible and should be kept in mind, at least for a selected high-risk patient subgroup. The main problems and comments regarding to endovascular technique for this subgroup are as follows.
Small true lumen may limit the vascular access, accurate deployment, and rotational movement of the stent graft. Precise preoperative three-dimensional reconstruction and mapping are needed for decision making and appropriate manipulation of the device.
The dissection flap including the visceral segments may limit the endovascular technique owing to possible malperfusion after the procedure. Preoperative precise definition of the origin of the visceral branch is needed. If the visceral branch is perfused from the false lumen, a combined surgical and endovascular procedure with visceral revascularization first may be required [3, 5]. At first sight, the right renal artery seemed to have originated from the false lumen in our case (Fig 2C), but the detailed examination of the contrast difference at the root of the renal artery revealed that it was perfused through the true lumen (Figs 2D, E). Control CT scan confirmed bilateral intact renal arteries (Fig 2F).
The aneurysm formation of a dissecting segment is usually slow (1 mm per year), thus reoperations are uncommon and prognosis is favorable [1]. But the rapid and progressive dilatation is associated with increased lifetime risk of complications [4]. The major determinant of aortic dilatation is the residual false luminal flow [1], which was probably the cause of quite fast and progressive dilatation in our case. Thus, the long-term success of any surgical or endovascular reoperation depends on the obliteration of the false luminal flow. Two intimal tears were detected on CT scan examination in our case, one at the descending aorta and one at the abdominal aorta. Both tears were covered with stents, and no residual false luminal flow was detected afterward (Fig 2F).
Deciding on the length of the graft should be done according to the localization of the intimal tear. Minimal necessary length to cover the intimal tear (which was 10 mm in this case) should be chosen. The intimal defects were detected with high-resolution multislice CT with multiplanar and three-dimensional reconstructions by an experienced team in our case. The localization of these defects were also confirmed by angiographic examination. After the deployment of the proximal graft, an additional angiographic evaluation should be performed during the procedure to detect any reentry points. Early postoperative multislice CT imaging is also necessary.
Deciding on the diameter of the graft should be done according to the precise evaluation of the predissected segment. The diameter of the graft was decided by 5% to 10% oversizing the diameter of the normal aorta at the predissected segment in our case. No evaluation of distal diameter was done. However, in the determination of graft size in the patients with discrete aneurysmal disease, we evaluate both the proximal and the distal size, and perform approximately 20% oversizing. In case of any diameter difference between the proximal and distal segment, we use tapered grafts.
In conclusion, endovascular treatment of thoracoabdominal aortic aneurysm of dissecting segments occurring after surgical treatment for acute type A dissection is feasible, at least for the patients with suitable aortic morphology. Preoperative accurate CT assessment for decision making and obliteration of false lumen are needed for the long-term success.
|
References
|
|---|
- Halstead JC, Meier M, Etz C, et al. The fate of the distal aorta after repair of acute type A aortic dissection J Thorac Cardiovasc Surg 2007;113:127-135.
- Roselli EE, Greenberg RK, Pfaff K, Francis C, Svensson LG, Lytle BW. Endovascular treatment of thoracoabdominal aortic aneurysms J Thorac Cardiovasc Surg 2007;133:1474-1482.[Abstract/Free Full Text]
- Resch TA, Greenberg RK, Lyden SP, et al. Combined staged procedures for the treatment of thoracoabdominal aneurysms J Endovasc Ther 2006;13:481-489.[Medline]
- Elefteriades J. Natural history of thoracic aortic aneurysms: indications for surgery, and surgical versus nonsurgical risks Ann Thorac Surg 2002;74:1877-1880.
- Gawenda M, Aleksic M, Heckenkamp J, Reichert W, Gossmann A, Brunkwall J. Hybrid procedures for the treatment of thoracoabdominal aortic aneurysms and dissections Eur J Vasc Endovasc Surg 2007;33:71-77.[Medline]
Top
Abstract
Introduction
