Multi-stage open surgical and endovascular treatment of progressive aortic degeneration in a patient with Marfan syndrome

Introduction

Marfan syndrome (MFS), a common inherited disorder of connective tissue with an incidence of approximately 1 in 3000 to 5000 persons is due to mutations in fibrillin-1, with pleotropic manifestations including the cardiovascular system. ¹ The major cause of morbidity and mortality for MFS patients is secondary to cardiovascular events including aortic aneurysm, dissection, or rupture. The primary management of acute aortic events in MFS is replacement of the diseased native segment with open surgical repair. Alternatively, thoracic endovascular aortic repair (TEVAR) with re-lining the diseased segment with an endovascular stent graft has also been described. ² The natural history for MFS is progressive degeneration of the entire aorta and thus these patients are at risk of needing repeat aortic interventions. We present an MFS patient with prior open thoracoabdominal aortic replacement who presents with progressive aortic degeneration managed with multiple open surgical and endovascular procedures.

Case report

A 35-year-old Caucasian male with MFS has a past surgical history of a valve-sparing aortic root replacement. He also had open repair of a 7 cm thoracoabdominal aortic aneurysm with placement of a 26 mm Dacron tube graft from the mid-descending thoracic aortic proximally with a distal beveled anastomosis just proximal to the superior mesenteric artery (SMA). There were two bypasses (8 mm Dacron) from the aortic graft to the celiac artery and a pair of large intercostal arteries. He was lost to follow-up and returned seven years later with a symptomatic 10 cm aneurysm of his native abdominal aorta seen on a computed tomography (CT) angiogram (Figure 1(a) and (b)).

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Figure 1.

Three-dimensional reconstruction of computed tomography angiographic images of the abdominal aortic aneurysm: (a) anterior-posterior projection and (b) left lateral projection.

To avoid the need for a re-operative open aortic procedure, the patient was treated with hybrid visceral debranching and aneurysm exclusion with aortic stent graft placement. A preoperative spinal drain was placed. An 8 mm Dacron graft was first sewn to a bifurcated 16 mm × 8 mm Dacron graft prior to surgical incision. Through a midline transabdominal approach, an open debranching was performed from the right common iliac artery to the SMA and bilateral renal arteries (Figure 2(a) to (c)). After debranching, a bifurcated 31 mm C3 Excluder (W.L. Gore, Flagstaff, AZ) and a proximal 34 mm TAG endoprosthesis (W.L. Gore, Flagstaff, AZ) was placed into the existing aortic tube graft just below the bypasses to the celiac artery and intercostal arteries. Two 20 mm Excluder iliac limbs were then deployed down to the level of the common iliac arteries bilaterally (Figure 2(d) to (f)). The devices were sized to the target anatomy according to the device’s instructions for use. The patient had an unremarkable postoperative course and the patient was discharged home on the 10th postoperative day with good blood pressure control.

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Figure 2.

Operative intervention for the large thoracoabdominal aortic aneurysm: (a) Transabdominal exposure of the aneurysm with vessel loops placed around the superior mesenteric, bilateral renal, and right common iliac arteries. (b) Placement of the multi-branched Dacron graft off the right common iliac artery to the visceral branches. (c) Angiographic representation of patent visceral bypasses during cannulation. (d) Positioning of the thoracic endograft within the partially deployed abdominal endograft. (e) Angiographic demonstration of proximal seal and (f) distal seal with patent visceral branches after endovascular repair.

The patient returned to the emergency room 24 h following discharge with acute back pain. His blood pressure was within normal limits and a CT angiogram demonstrated an acute dissection in the residual untreated thoracic aorta from just distal to the left subclavian artery to the location of the prior tube graft repair (Figure 3(a) to (c)). He was medically managed with impulse control and was discharged. He refused imaging follow-up until one year later when a CT angiogram showed aneurysmal degeneration of his remaining native descending thoracic aorta to 7 cm and a new distal IB endoleak from the left common iliac artery. He underwent a redo-sternotomy with an open distal aortic arch replacement with a 26 mm Dacron elephant trunk placement. This was followed by a staged endovascular completion during the same hospitalization with a placement of two overlapping 34 mm TAG endoprosthesis from the elephant trunk down to his prior aortic tube graft (Figure 3(d) to (f)). A 23 mm excluder iliac extension was placed into the left common iliac artery down to the iliac bifurcation to successfully exclude the distal IB endoleak (Figure 3(g)). On imaging six month later, he was found to have recurrence of the distal IB endoleak with progressive aneurysmal degeneration of the left common iliac artery. This was treated with a retroperitoneal exposure and the distal stent graft was primarily anastomosed (reinforced with felt strip) to the native distal common iliac artery (Figure 4(a) and (b)). The patient is doing well 36 months after his most recent procedure with a stable vascular repair (Figure 4(c)).

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Figure 3.

Operative intervention for the large thoracic aneurysm and distal endoleak. (a) Sagittal and (b) axial image from a computed tomography angiogram (CTA) showing the type B dissection distal to the left subclavian to the level of prior open aortic repair. (c) CTA image showing distal IB endoleak at the left common iliac seal zone. (d) Thoracic aortic angiogram demonstrating the elephant trunk within the large thoracic aneurysm. (e) Angiographic demonstration of proximal seal and (f) distal seal with patent celiac and intercostal bypasses demonstrated. (g) Successful endovascular repair of the distal IB endoleak.

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Figure 4.

Operative intervention for the recurrent distal type IB endoleak. (a) Three-dimensional reconstruction of computed tomography angiographic (CTA) image showing preoperative anatomy. (b) Retroperitoneal exposure and primary repair of the endoleak with felt-reinforced direct anastomosis of the left iliac endograft to the native distal common iliac artery. (c) Follow-up CTA demonstrating successful aneurysm exclusion and patent bypasses.

Discussion

The treatment of aortic pathology in patients with underlying connective tissues orders presents unique challenges. The eventual degeneration of the entire aorta often leads to multiple separate acute aortic processes that develop over many years and mandate the need for repeat operative interventions. In a series of 95 patients with MFS, 9.7% required re-operation for the thoracic aorta following an elective root repair and >40% required re-intervention following a type A dissection with an ascending aortic repair. ³ In a more recent series, it was identified that the presence of a dissection (acute or chronic) predicts the need for emergent surgery as well as the need for additional aortic surgery. ⁴ The use of TEVAR in these complex patients help obviate the high rate of mortality and morbidity associated with reoperative aortic intervention. However, its use is controversial and there can be a significant amount of complications on mid-term follow-up. This may be related to the fact that endovascular devices can subject otherwise fragile aortic tissue to increased radial force or direct aortic injury leading to rapid aneurysm degeneration. ⁵ This process can certainly be magnified if there is an underlying connective tissue disorder.

Despite its limitations, endovascular intervention is being utilized in patients with connective tissue disorders. ⁶ Endovascular repair has been recommended if patients are felt to be too high-risk for open surgery performed at a major aortic center, or if the indication for repair is aortic rupture. It has also been recommended that the stent graft should use a previously placed graft as landing seal zones. ⁷ The available literature on endovascular treatment in MFS patients remain limited. A report of 16 MFS patients with a mix of aortic pathology (dissection and aneurysm), acuity (acute and chronic), and treatment (thoracic and abdominal aorta) all had prior aortic interventions. ⁸ With a median follow-up of 9.3 months, there was a 38% success of initial endovascular therapy, a 44% primary treatment failure (resulting in secondary intervention or death), and an overall 25% mortality rate. In another study evaluating 10 MFS patients presenting with acute aortic syndrome complicating a type B aortic dissection, five patients underwent a Bentall surgical procedure prior to TEVAR, four had initial TEVAR followed by open ascending aortic repair at a later date, and one patient underwent TEVAR alone. ⁹ The in-hospital mortality was 10% when one patient died from an aortic rupture during open repair after initial TEVAR. At a mean follow-up of five years, the cumulative mortality rate was 20%. The rate of secondary endoleak was 44.4% and late reintervention rate was 33.3%. Positive remodeling was documented in only three patients (37.5%). In a systematic review looking at 54 patients managed with TEVAR for type B dissection, it was noted that 80% had undergone a prior cardiovascular procedure. ² With an average follow-up of 2.5 years, there was a 22% endoleak rate, 13% mortality rate, 16% rate of endovascular reintervention, and 18% rate of open surgical conversion. It should be noted that there were no endoleaks reported when an endograft landing zone was within a segment of previously replaced aorta. A total endovascular aortic repair in a patient with MFS has also been reported. ¹⁰ The patient had staged repair with endovascular arch repair using an inner branched device to exclude a large distal arch aneurysm. This was followed by additional placement of a thoracic stent graft and fenestrated endograft for his thoracoabdominal aortic aneurysm.

This case of a young MFS patient exemplifies the difficulty in treating patients with underlying connective tissue diseases. We utilized both open and endovascular approaches to mitigate the increased difficulty and increased morbidity and mortality of re-operative aortic surgery. We chose a hybrid approach with this challenging situation and proceeded with a visceral debranching which was achieved off the right iliac system to minimize the risk of dissection around the prior distal anastomosis. A combined endovascular and surgical approach with surgical debranching and endograft placement to treat thoracoabdominal aneurysms was first described over two decades ago. ¹¹ A meta-analysis of 507 patients showed excellent technical success and visceral graft patency, but this procedure is still associated with significant morbidity and mortality rates in these otherwise poor surgical candidates. ¹² The endovascular portion of the procedure was designed to use the previously placed Dacron graft as the proximal landing zone. However, the use of his native iliac arteries as a distal landing zone did lead to the development of recurrent distal endoleaks on the left side that ultimately required open reconstruction. We will have to continue to carefully monitor the right iliac artery for potential degeneration in the future. If surgical intervention is required, the maintenance of perfusion to the visceral branches during clamping will have to be carefully preserved. It is also important to note that this patient also developed a concomitant aortic dissection during his treatment that necessitated additional thoracic aortic intervention. The etiology of this remains unclear and it can certainly just be demonstrative of the fragility of the aorta in patients with connective tissue disorders. However, there was insertion of wires into this portion of the aorta and its role in the dissection formation cannot be excluded. This patient is fortunately doing well three years after his last intervention but will need to have continued close follow-up.

Conclusion

This case illustrates the challenges in treating a patient with an underlying connective tissue disorder and the need for consistent postoperative surveillance. The combined use of open and endovascular techniques facilitated management of his multiple aortic pathologies. In patients with MFS, endovascular techniques are best applied when the landing zones are within previously replaced aorto-iliac segments. Stringent post-procedural imaging follow-up is mandatory to ensure long-term durable treatment success.