Thoracic and Thoracoabdominal Aneurysms: Etiology, Epidemiology, and Natural History

Thoracic aortic aneurysms and thoracoabdominal aneurysms are often found incidentally. Complications include dissection or rupture. Most of the thoracic aortic aneurysms and thoracoabdominal aneurysms develop in patients with risk factors for atherosclerosis. Younger patients without significant cardiovascular risk factors may have a genetic basis and include syndromes such as Marfan, Ehlers-Danlos, and Loeys-Dietz and bicuspid aortic valve. Most thoracic aneurysms grow slowly over time and factors that accelerate growth rate include dissection, aneurysm size, bicuspid valve disease, and Marfan syndrome. Size cutoffs where complications occur determine when surgery or intervention should be considered.

Complications after thoracic endovascular aortic repair for ruptured thoracic aortic aneurysms remain high compared with elective repair

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) for ruptured thoracic aortic aneurysms is associated with increased perioperative mortality and morbidity compared with intact repair. The purpose of our study was to evaluate the factors associated with the presentation of ruptured aneurysms and adverse outcomes after repair.

METHODS

The Vascular Quality Initiative (VQI) registry was queried (2010-2020) to identify patients who had undergone TEVAR for ruptured and intact thoracic aortic aneurysms. The primary outcome was to identify the factors associated with ruptured thoracic aortic aneurysms. The secondary outcomes included perioperative mortality and morbidity, 5-year survival, and the identification of factors associated with adverse outcomes after TEVAR.

RESULTS

Of the 3039 patients identified with a thoracic aortic aneurysm, 2806 (92%) had undergone repair for an intact aneurysm and 233 (8%) had undergone repair for a ruptured aneurysm. Chronic kidney disease was associated with a greater odds of a presentation with a ruptured aneurysm (odds ratio [OR], 3.1; 95% confidence interval [CI], 2.0-4.9; P < .001). The factors associated with a lower odds of rupture included prior aortic aneurysm repair (OR, 0.71; 95% CI, 0.49-0.97; P = .05), prior smoker (OR, 0.36; 95% CI, 0.24-0.53; P < .001), preoperative beta-blocker therapy (OR, 0.57; 95% CI, 0.41-0.80; P = .001), and preoperative statin therapy (OR, 0.68; 95% CI, 0.49-0.94; P = .020). TEVAR for ruptured thoracic aortic aneurysms was associated with higher perioperative mortality (rupture vs intact, 27% vs 4.6%; OR, 6.6; 95% CI 4.3-10; P < .001) and the composite outcome of mortality, new dialysis, paralysis, and stroke (38% vs 9.5%; OR, 5.1; 95% CI, 3.5-7.4; P < .001). The 5-year survival was significantly lower after TEVAR for ruptured thoracic aortic aneurysms (50% vs 76%; P < .001; hazard ratio, 0.39; 95% CI, 0.29-0.52; P < .001). Preoperative statin therapy was associated with higher 5-year survival (hazard ratio, 1.3; 95% CI, 1.0-1.6; P = .021).

CONCLUSIONS

TEVAR for ruptured thoracic aortic aneurysms results in increased perioperative mortality and morbidity and lower 5-year survival compared with TEVAR for intact aneurysms. Patients with prior aortic aneurysm repair, prior smoking, and preoperative beta-blocker or statin therapy were less likely to present with ruptured thoracic aneurysms. This correlation might be attributed to increased exposure to cardiovascular healthcare providers and, thus, subsequently increased screening and surveillance, allowing for elective repair of thoracic aortic aneurysms.

Impact of frailty on early and mid-term outcomes of hybrid aortic arch repair

PURPOSE

The purpose of this study was to investigate the impact of frailty on the clinical outcomes of hybrid aortic arch repair with debranching of the supra-aortic arteries.

METHODS

Consecutive patients ≥ 75 years old who underwent hybrid aortic arch repair from January 2010 to December 2019 were retrospectively analyzed. Using the Canadian Study of Health and Aging (CSHA) scale, all patients with a CSHA scale score > 4 were defined as frail. The frail patients (FP) group and the non-frail patients (NFP) group were compared regarding the early and mid-term outcomes of hybrid aortic arch repair.

RESULTS

A total of 84 patients were included. The early postoperative results were not markedly different between the groups, except that the rate of transfer to a rehabilitation hospital was higher in the FP group than in the NFP group. The survival at 5 years was significantly lower in the FP group at 43.0% than in the NFP group at 67.7% (P = 0.015). However, the freedom from aorta-related death was not significantly different between the two groups.

CONCLUSION

Frailty did not affect the short-term outcomes of hybrid aortic arch repair; however, the mid-term outcomes, including the survival, of the frail patients were significantly worse than those of the non-frail patients, mostly because of non-aorta-related causes.

Total Percutaneous Access for Deployment of a Custom Made Fenestrated Stent Graft in a 90 Year Old with a Large Symptomatic Thoracic Aortic Aneurysm

Introduction

Open surgical cut down has been the standard for gaining carotid access in most thoracic endovascular repairs of aortic aneurysm (TEVAR) cases; however, when suitable, total percutaneous repair can be beneficial.

Report

A relatively fit 90 year old man with few medical comorbidities presented with six months of worsening upper back pain and an Ishimaru zone 2 fusiform thoracic aortic aneurysm of 7.2 cm diagnosed on CT aortography. A total percutaneously inserted custom made device (CMD) with innominate artery (IA) scallop, left common carotid artery (LCCA) fenestration combined with left subclavian artery (LSA) occlusion provided an effective repair. Haemostasis was obtained with Abbott Perclose ProGlide suture-mediated devices. The patient was discharged on post-operative day two. Follow up CT at one month was unremarkable without any endoleak, and an improvement in symptoms.

Discussion

There are risks of cerebral ischaemia and other complications with open carotid cut down, hence it is worth considering avoiding if possible, especially for select patients. Retrograde carotid access and subsequent closure device deployment is not new, but in conjunction with CMD, TEVAR allowing for carotid stenting is feasible and less often described in the literature.

Ortner syndrome secondary to saccular thoracic aneurysm

Mechanical stretching of the left laryngeal nerve secondary to an enlarged left atrium was first described by Dr Norbert Ortner in 1987. An extensive literature search revealed only 76 reported cases of Ortner syndrome, with the more recent reports describing other causes of the syndrome such as pulmonary hypertension, aortic dissection, and a thoracic aneurysm. We recently encountered this rare pathologic entity in an elderly man who had presented with severe hoarseness, presumed to be due to one of the aforementioned vascular anomalies. In the present report, we have highlighted the pathology and hybrid repair of this challenging entity.

A preliminary analysis of late structural failures of the Navion stent graft in the treatment of descending thoracic aortic aneurysms

OBJECTIVE

Patients in the Valiant Evo U.S. and international clinical trials had positive short-term outcomes; however, late structural failures, including type IIIb endoleaks have been recently discovered. Type IIIb endoleaks are serious adverse events because the repressurization of the aneurysm sac increases the risk of rupture. The purpose of the present study was to detail the imaging patterns associated with the structural failures with the aim of increasing awareness of failing graft presentation, early recognition, and prompt treatment.

METHODS

The Valiant Evo clinical trial was a prospective, single-arm investigation of a thoracic stent graft system. With the recent late structural failures, sites were requested to submit all available imaging studies to date to allow the core laboratory to assess for structural failures such as type IIIb endoleaks, stent ring fractures, and stent ring enlargement. Of the 100 patients originally enrolled in the trial from 2016 to 2018, the core laboratory assessed the imaging studies performed at ≥1 year for 83 patients.

RESULTS

No structural failures of the graft were reported through 1 year of follow-up. At 1 to 4 years, graft structural failures were detected in 11 patients with descending thoracic aortic aneurysms. Of the 11 patients, 5 had a type IIIb endoleak. Four of the five had imaging findings showing stent fractures consistent with the location of the graft seam and one had a type IIIb endoleak attributed to calcium erosion with no stent fracture or ring enlargement. Of the four patients with stent fracture in line with the graft seam, three underwent a relining procedure that successfully excluded the type IIIb endoleak. One of these three patients died 4 days later of suspected thoracic aortic rupture because the distal thoracic endovascular aortic repair extension had been landed in a previously dissected and fragile section of the aorta. The remaining six patients had had stent ring enlargement. One of the six patients had had persistent aneurysm expansion from the time of implantation onward and had died of unknown causes. The remaining five patients have continued to be monitored.

CONCLUSIONS

In the present preliminary analysis, the imaging patterns associated with type IIIb endoleaks, stent fractures, and stent ring enlargement appear to be related to the loss of seam integrity or detachment of the stent rings from the surface of the graft material. The imaging patterns we have detailed should be closely monitored using computed tomography angiography surveillance to allow structural failures to be promptly identified and treated.

Emergent open conversion for stent-graft deployment failure in a ruptured thoracic aneurysm

Thoracic endovascular aortic repair (TEVAR) is the standard of care for ruptured thoracic aortic aneurysms. A 92-year-old man had presented in stable condition but with acute severe back pain. Computed tomography revealed a ruptured thoracic aortic aneurysm. TEVAR (Valiant; Medtronic Vascular, Santa Rosa, Calif) into zone 2 with intentional coverage of the left subclavian artery was planned. After release of the stent-graft body, proximal release of the bare springs was impossible. Troubleshooting techniques were applied; but tip capture could not be released. Emergent conversion to open repair was performed. Intraoperative device deployment failure in TEVAR is rare. The findings from the present report have demonstrated the advantages of having in-house cardiac surgery backup available.

Ascending Aortic Diameter after Dissection Does Not Reflect Size before Dissection

Introduction

Current guidelines for prophylactic resection of ascending aortic aneurysms are based on post-dissection aortic diameter. However, this may not reflect the diameter prior to dissection.

Report

Pre- and post-dissection aortic diameters were compared in 34 patients with available computerised tomography scans. The median time interval between these scans was 536 days (interquartile range 354 – 1237).

Discussion

There was a statistically significant difference in diameters from the sinotubular junction to the proximal abdominal aorta, the largest was in the ascending aorta with a mean of 7.6 mm (standard deviation 4.5). This suggests that the ascending aortic diameter is a poor predictor of dissection in most patients.

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Ascending aortic diameter expands due to acute dissection.

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Post-dissection aortic diameters probably overestimate pre-dissection diameters.

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Following ascending dissection, diameter expansion is not limited to aorta ascendens.

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In this sample, estimated pre-dissection ascending aortic diameters were below 60 mm in 91% of patients and below 50 mm in 85%.

Thoracic endovascular aortic repair with true-false-true lumen deployment

Endovascular treatment of aortic dissection may be complicated by challenges to navigating the true lumen. In this report, we describe treatment of a type B dissection after open type A repair with aneurysmal degeneration, a short-segment occluded true lumen, and a distal re-entry tear near the celiac artery origin. Endovascular septal fenestration and subsequent thoracic endovascular aortic repair were used to bypass the short-segment midthoracic aortic occlusion, successfully excluding the thoracic aortic aneurysm. The patient was discharged without complications, and follow-up imaging demonstrated favorable aortic remodeling. The case demonstrates feasibility of an endovascular bypass of an intervening short-segment occluded true lumen using a thoracic endovascular aortic repair with true-false-true lumen deployment.

Successful endovascular coil embolization of large pseudoaneurysm of ductus arteriosus diverticulum

Background

Pseudoaneurysm of the ductus arteriosus diverticulum, although rare in adults, may have catastrophic consequences if left untreated due to erosion and rupture of the pseudoaneurysm into adjacent thoracic structures. Although thoracic endovascular aortic repair (TEVAR) is the standard treatment method for aneurysm closure of the ductus arteriosus diverticulum, it was not possible in our patient secondary to marked aortoiliac access vessel tortuosity, significant vascular calcific burden, and an abdominal aortic aneurysm. We describe the first reported case of endovascular coil embolization being successfully used as the definite repair of a ductus arteriosus diverticulum pseudoaneurysm.

Case presentation

An 85-year-old man with history of severe coronary arterial disease presented with an enlarging pseudoaneurysm of a ductus arteriosus diverticulum. The diverticulum and thoracic aortic junction demonstrated the typical obtuse angles and wide neck, differentiating it from otherwise similar-appearing diagnostic considerations. Repair was attempted with conventional aortic stent graft but the patient’s infrarenal abdominal aortic aneurysm and his heavily calcified, tortuous iliac vessels could not accommodate the 24Fr introducer sheath necessary for stent graft placement. Therefore, endovascular coil embolization was successfully completed through a 4Fr directional catheter. The patient tolerated the procedure well and was discharged from the hospital in good condition on post-embolization day six.

Conclusions

Endovascular coil embolization is an alternative treatment for ductus arteriosus diverticulum pseudoaneurysm closure in cases where the standard TEVAR method is unsuccessful. Instead of the wide entry point at the aorta we used the junction of the diverticulum and pseudoaneurysm as the “neck” for satisfactory and stable coil placement. Endovascular coil embolization alone may be a viable definitive therapy for occlusion of the ductus pseudoaneurysm component of the diverticulum in cases where complex anatomy or extensive vascular disease makes stent graft repair impractical if not impossible.

Hybrid treatment of a giant thoracic aneurysm in a 38 year-old woman

A 38-year-old woman, with no comorbidities, presented to an outside institution with a 10-cm aortic arch and descending thoracic aortic aneurysm. After an aborted attempt at hybrid repair, she underwent successful, staged repair with zone 1 thoracic endovascular aortic repair and open aneurysmal sac revision. The patient made an uneventful recovery with computed tomographic evidence of complete aneurysmal exclusion. This case demonstrates many of the techniques and issues in the evolving field of aortic arch repair.

Endovascular repair of a ruptured thoracic aortic dissection with a right sided aortic arch: A case report

BACKGROUND

Emergency treatment of complex aortic pathology is challenging in the setting of a right-sided aortic arch. We report the successful treatment of a ruptured thoracic aortic aneurysm (TAA) in the setting of a Stanford type B aortic dissection (TBAD) and right-sided aortic arch.

PRESENTATION OF CASE

The patient is a 66-year-old male with chronic kidney disease (CKD) admitted with right sided chest pain and hypotension. Computed tomography angiography (CTA) revealed a 5cm ruptured TAA in the setting of a TBAD and right-sided aortic arch. The TBAD began just distal to the right common carotid artery and involved the origin of the left subclavian artery (SCA). Using a totally percutaneous approach, a conformable Gore^® TAG^® thoracic endoprosthesis was placed in proximal descending thoracic aorta covering the left SCA. Aside from progression of his pre-existing CKD, the patient had an uneventful recovery. CTA one-month post-procedure revealed a type IB endoleak with degeneration of the distal descending thoracic aorta. To exclude the endoleak, the repair was extended distally using a Medtronic Valiant^® thoracic stent graft. The left subclavian artery was subsequently coil embolized to treat an additional retrograde endoleak. The patient has done well with no further evidence of endoleak or aneurysm expansion.

CONCLUSION

Right-sided aortic arch presents challenges in the emergency setting. CTA and post-processing reconstructions are very helpful. While the endoleaks prompted additional interventions, the end result was excellent. This case displays the importance of careful attention to detail and follow-up in these complicated patients.

Systolic flow displacement using 3D magnetic resonance imaging in an experimental model of ascending aorta aneurysm: impact of rheological factors

OBJECTIVES

The impact of systolic flow displacement on the development and progression of ascending aorta dilatation in aortic valve disease is a matter of controversy. Our objective was to study the association between rheological stimuli and development of aortic dilatation in a large animal model of supravalvular aortic stenosis and eccentric flow.

METHODS

Twenty-four pigs weighing 10-14 kg were randomly allocated (ratio 2:1) to either restrictive ascending aortic banding or sham operation. Aortic diameter and systolic flow displacement were assessed by three-dimensional phase-contrast magnetic resonance imaging at 6 and 18 weeks after surgery. Twenty pigs (n = 14, banded vs n = 6, sham) completed full imaging protocol and were included in the analysis. After the last follow-up, a subset of 14 animals was sacrificed for histological analysis.

RESULTS

All banded animals developed significant progressive aortic dilatation both at 6 and 18 weeks, compared with sham-operated pigs: 34.3 ± 4.8 vs 21.4 ± 2.7 mm at 6 weeks (P < 0.001); and 50.0 ± 8.4 vs 38.0 ± 8.3 mm at 18 weeks (P = 0.002). The peak gradient at 6 weeks showed a trend to positively correlate with aortic diameter at 18 weeks (R = 0.50, P = 0.06), whereas the systolic flow displacement at 6 weeks correlated better with aortic diameter at 18 weeks (R = 0.59, P = 0.02). The aortic wall thickness was significantly decreased in the anterior aortic section in banded, compared with sham-operated, pigs (1.5 ± 0.4 vs 2.0 ± 0.1 mm, respectively; P = 0.03). In addition, banded pigs showed a higher degree of cystic medial necrosis and elastin fibre fragmentation, compared with sham-operated animals.

CONCLUSIONS

In this preclinical model of supravalvular aortic stenosis and eccentric flow, we found that systolic flow displacement at earlier stages is positively correlated with the degree of aortic dilatation during follow-up as assessed by three-dimensional phase-contrast magnetic resonance imaging. If our findings are confirmed in further studies, this imaging parameter might be useful to identify those subjects with aortic valve disease who are at risk of developing aortic dilatation at a later stage.

New molecular genetic tests in the diagnosis of heart disease

With the increasing use of next-generation sequencing applications, there has been an increase in identification of genetic causes of cardiac disease. This technology has also enabled the transition of these genes into the clinical setting and the rapid growth of large gene tests for the diagnosis of heart disorders. The ability to combine tests to include similar, but distinct, diseases has shown that many genes can be responsible for a wide variety of both syndromic and nonsyndromic disorders. This article discusses the current state of molecular genetic diagnosis for cardiac disorders, focusing on diseases with mendelian inheritance.

Advanced atherosclerosis is associated with increased medial degeneration in sporadic ascending aortic aneurysms

OBJECTIVE

The pathogenesis of non-familial, sporadic ascending aortic aneurysms (SAAA) is poorly understood, and the relationship between ascending aortic atherosclerosis and medial degeneration is unclear. We evaluated the prevalence and severity of aortic atherosclerosis and its association with medial degeneration in SAAA.

METHODS AND RESULTS

Atherosclerosis was characterized in ascending aortic tissues collected from 68 SAAA patients (mean age, 62.9 ± 12.0 years) and 15 controls (mean age, 56.6 ± 11.4 years [P = 0.07]) by using a modified American Heart Association classification system. Upon histologic examination, 97% of SAAA patients and 73% of controls showed atherosclerotic changes. Most SAAA samples had intermediate (types 2 and 3, 35%) or advanced atherosclerosis (types ≥ 4; 40%), whereas most control samples showed minimal atherosclerosis (none or type 1, 80%; P < 0.001 after adjusting for age). In a separate analysis, we examined the total incidence and grade distribution of medial degenerative changes among SAAA samples according to atherosclerosis grade. Advanced atherosclerosis was associated with higher grades of smooth muscle cell depletion (P < 0.001), elastic fiber depletion (P = 0.02), elastic fiber fragmentation (P < 0.001), and mucopolysaccharide accumulation (P = 0.04). Aortic diameter was larger in SAAA patients with advanced atherosclerosis than in patients with minimal (P = 0.04) or intermediate atherosclerosis (P = 0.04). Immunostaining showed marked CD3+ T-cell and CD68+ macrophage infiltration, MMP-2 and MMP-9 production, and cryopyrin expression in the medial layer adjacent to atherosclerotic plaque.

CONCLUSIONS

SAAA tissues exhibited advanced atherosclerosis that was associated with severe medial degeneration and increased aortic diameter. Our findings suggest a role for atherosclerosis in the progression of sporadic ascending aortic aneurysms.

Early experience of thoracic endovascular aortic repair: a local single hospital experience

Purpose

The purpose of this retrospective study was to evaluate the short- to mid-term results of thoracic endovascular aortic repair (TEVAR) in Wonkwang University School of Medicine & Hospital.

Methods

Between February 2009 and May 2011, 8 consecutive patients had undergone endovascular stent-grafting for thoracic aortic diseases. Five patients were treated for traumatic thoracic aortic injuries, two patients were treated for thoracic aneurysms and one patient was treated for a pseudoaneurysm due to penetrating aortic ulcers. Attempted stent-graft deployment was performed electively in 6 patients and emergently in 2. Follow-up was performed at 1-month, 6-month, 1-year, and annually thereafter.

Results

Technical success rates were achieved in 87.5% and the 30-day mortality rate was 0%. Mean hospital length of stay after TEVAR was 30 days in traumatic thoracic aortic injuries and 10 days in thoracic aneurismal diseases. Intra-operative Type I endoleak due to migration at deflation was visualized in 1 patient, which was treated by insertion of another stent-graft. During follow-up, a major complication was encountered in one patient who received carotid-subclavian bypass to relieve left arm ischemia. After 5 months he was treated with arch replacement for aortic arch aneurysm with type I endoleak at proximal site after endovascular treatment. The 30-day mortality rate was 0%. However, 1 case of mortality (12.5%) was observed during the follow-up period.

Conclusion

The short and mid-term results of endovascular repair of thoracic aortic diseases are promising. TEVAR is an effective procedure in the management of thoracic aortic diseases.