Endovascular aortic repair has been successful in the treatment of thoracic aortic aneurysms. However, the vast majority of these patients are elderly. Young patients pose specific anatomic challenges, as well as long-term durability issues, when endovascular prostheses are used.

CASE REPORT

A 37-year-old woman presented with cough and coldlike symptoms. The patient had a documented medical history of Crohn's disease, a 20-pack-per-year cigarette smoking history, and a motor vehicle accident at age 11. A chest x-ray revealed an enlarged thoracic aortic shadow, and the patient underwent fine-cut computed tomography (CT) angiography of the chest (Figure 1). The CT scan revealed a fusiform descending thoracic aortic aneurysm with a maximal diameter of 5.8 cm, which was more than twice the diameter of the aorta above and below the aneurysm.

The etiology of the aneurysm was unclear. There was no definite intimal flap or pseudoaneurysm to confirm that this was secondary to a localized dissection or a blunt traumatic aortic injury that was incurred at the time of the motor vehicle accident 26 years ago. No interval imaging was available for comparison. Hypertensive or atherosclerotic disease seemed even less likely, given that she was normotensive, and there was no degenerative or atherosclerotic disease evident in the rest of the thoracic or abdominal aorta.

Intervention was deemed to be appropriate to prevent aortic rupture. It was believed that the patient could undergo either endovascular or open repair via a thoracotomy. After discussing the risks and benefits of both options, an endovascular approach was selected.

Detailed CT analysis revealed a proximal landing zone diameter 3 cm distal to the left subclavian artery of 20 mm (Figure 2). The distal landing zone was only 16 mm in diameter. Estimated total length of coverage needed was 12 to 14 cm.

PROCEDURE

The procedure was performed under general anesthesia in the operating room with intraoperative transesophageal echocardiographic guidance and fluoroscopy. We decided preoperatively not to insert a spinal cord drain, but instead, to wake the patient up on the operating room table, assess her neurological status, and be ready to insert a cerebrospinal fluid drain if needed.

The right femoral artery was accessed via a 1.5-inch transverse groin incision, 5,000 units of intravenous heparin was administered, and a 20-F GORE® DrySeal Sheath (Gore & Associates) was placed. Under fluoroscopic guidance, a 26-mm X 26-mm X 10-cm Conformable GORE® TAG® Device (Gore & Associates) was advanced over a Lunderquist Extra-Stiff wire (Cook Medical, Bloomington, IN) and deployed 2 cm distal to the left subclavian artery (Figure 3). The second device was a tapered, 26-mm X 21-mm X 10-cm Conformable GORE® TAG® Device, which was inserted distally, providing 5 cm of overlap coverage between the two stent grafts. Completion angiography (Figure 4) was performed, and the femoral artery was repaired with interrupted PROLENE® Sutures. The patient was extubated on the operating table and was neurologically intact. A postoperative CT scan revealed exclusion of the aneurysm sac with no endoleak (Figure 5). The patient was discharged home 3 days later.

ANATOMIC CHALLENGES OF YOUNG PATIENTS

In young patients, landing zone sites can often have a small diameter. This patient's 16-mm distal landing zone would traditionally be a contraindication to endovascular repair. However, the expanded sizing indications of the Conformable GORE® TAG® Device accommodate a 16-mm aorta with a 21-mm device, resulting in 31% oversizing. In young patients, a longlasting durable repair is of consequence. The longterm outcome of thoracic endovascular aortic repair (TEVAR) beyond 10 years is not yet defined. The “normal” non-diseased aortic diameter is known to increase over time. There is a risk of delayed endoleak formation as the device fails to remain opposed to the expanding aorta. In this case, the 31% oversizing of the distal landing zone should, theoretically, be able to maintain wall apposition over time.

A tapered graft is also useful in young patients who have uniform tapering of the non-diseased segment of their thoracic aorta. The tapered Conformable GORE® TAG® Device graft allows for accommodation of proximal and distal landing zone diameters.

When treating young patients, physicians have to be aware of the future ramifications of the endovascular prosthesis. Apart from the fact that patients with thoracic aortic endografts are likely to require lifelong surveillance imaging, there are many other reasons that a patient might require magnetic resonance imaging (MRI) during the next 3, 4, or 5 decades. With the Conformable GORE® TAG® Device being MRI compatible, the patient will not be exposed to annual radiation from surveillance CT scans. In addition, endovascular treatment does not result in a contraindication to MRI for neurologic, orthopedic, cardiac, or other reasons.

OPEN SURGERY VERSUS ENDOVASCULAR REPAIR

Both open and endovascular repair techniques are performed in the cardiac surgery operating room by a multidisciplinary team trained in both open and endovascular surgery, allowing for fair assessment of the risks and benefits associated with each approach. The advantages of an open operation would be a more known/understood long-term result. Endovascular surgery has been shown to have a lower risk of spinal cord ischemia and mortality and a similar risk of stroke versus open surgery for descending thoracic aortic aneurysms.1 Other advantages of TEVAR include less pain, cosmesis, and quicker recovery—all of which were important to the young woman in this case. The procedure was also planned in such a way that TEVAR would not unnecessarily complicate future open repair, should the patient require surgical graft revision. As the graft was not encroaching on the arch, the descending thoracic aorta could be clamped distal to the left subclavian artery and resected via a thoracotomy if necessitated by infection or delayed graft failure.

FOLLOW-UP

Our patient was a busy mother of three children and returned to full-time employment 1 week postoperatively. She was very grateful to avoid a thoracotomy incision. A follow-up CT scan at 6 months revealed no evidence of complications. Going forward, annual follow-up will be performed via MRI.

CONCLUSION

The diameter range, oversizing ability, presence of tapered grafts, and MRI compatability of the Conformable GORE® TAG® Device provides unique solutions to some of the challenges of treating thoracic aortic aneurysms in young patients.

Jehangir J. Appoo, MDCM, is an assistant professor with the Division of Cardiac Surgery, Libin Cardiovascular Association, University of Calgary in Calgary in Alberta, Canada. He has disclosed that he is a consultant to Gore & Associates. Dr. Appoo may be reached at jehangir. appoo@albertahealthservices.ca.

  1. Bavaria JE, Appoo JJ, Makaroun MS, et al. Endovascular stent grafting vs. open surgical repair of descending thoracic aortic aneurysms in low risk patients: a multicentre comparative trial. J Thorac Cardiovasc Surg. 2007;133:269-277.