Pulmonary artery aneurysm with ascending aortic aneurysm concomitant with bilateral bicuspid semilunar valves

Aneurysm of both the pulmonary trunk and the ascending aorta concomitant with bilateral bicuspid valves is very rare. The reason for the formation of aneurysm with bicuspid semilunar valve is still inconclusive. Surgical repair was performed successfully (ie, aortic valve replacement, graft replacement for the ascending aorta, and plication of the pulmonary artery). Pathology of the pulmonary artery wall did not demonstrate cystic medial necrosis. The hemodynamic turbulence by the bilateral bicuspid valve may cause the formation of aneurysms even at low pressure. This case demonstrates an explanation for aneurysm with the bicuspid valve.     

Failure properties of ascending thoracic aortic aneurysms with dysfunctional tricuspid aortic valves

 Open in a separate windowOBJECTIVESAscending thoracic aortic aneurysms (ATAAs) often coexist with dysfunctional tricuspid aortic valves (TAVs). How valvular pathology relates to the aortic wall mechanical properties requires detailed examination.METHODSIntact-wall and layer-specific mechanical properties from 40 and 21 patients with TAV-ATAAs, respectively, were studied using uniaxial tensile testing, longitudinally and circumferentially. Failure stress (tensile strength), failure stretch (extensibility) and peak elastic modulus (stiffness) measurements, along with histological assays of thickness and elastin/collagen contents, were compared among patients with no valvular pathology (NVP), aortic stenosis (AS) or aortic insufficiency (AI).RESULTSIntact-wall stiffness longitudinally and medial strength and stiffness, in either direction, were significantly lower in AI patients than in AS and NVP patients. Intact-wall/medial thickness and extensibility in either direction were significantly lower in AS patients than in AI and NVP patients. In contrast, intact-wall/medial stiffness circumferentially was significantly higher in AS patients than in NVP patients, consistent with the significantly increased medial collagen in AS patients. Failure properties and medial thickness and elastin/collagen contents were significantly lower (more impaired) in females. The left lateral was the thickest quadrant in NVP patients, but the 4 quadrants were equally thick in AS and AI patients. There were significant differences in strength and stiffness among quadrants, which varied however in the 3 patient groups.CONCLUSIONSThe aortic wall load-bearing capacity was impaired in patients with ATAA in the presence of TAV stenosis or insufficiency. These findings lend biomechanical support to the current guidelines suggesting lower thresholds for elective ascending aorta replacement in cases of aortic valve surgery.     

Matrix metalloproteinases in ascending aortic aneurysms: bicuspid versus trileaflet aortic valves

BACKGROUND: Abnormal matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinase (TIMP) expression contributes to the development of abdominal aortic aneurysms. Recent data suggest that MMP-2 and MMP-9 may also play a role in thoracic aortic disease. We sought to determine (1) whether ascending aortic aneurysms are associated with increased MMP expression and (2) whether aortic inflammation and MMP expression differ between patients with congenital bicuspid aortic valves (BAVs) and those with trileaflet aortic valves (TAVs). MATERIALS AND METHODS: Samples of ascending aortic aneurysms were obtained from 29 patients; 14 patients had BAVs and 15 had TAVs. Control ascending aorta was obtained from 14 organ donors or heart transplant recipients. Aortic histology and immunohistochemistry were performed to evaluate elastin degradation, inflammatory changes, and MMP-2 and MMP-9 expression. Aortic levels of MMP-2, MMP-9, TIMP-1, and TIMP-2 were measured using ELISA. RESULTS: Aneurysms in the TAV patients exhibited marked inflammation, high CD68 expression, diminished elastin content, increased MMP-9 expression, and normal MMP-2 levels. In contrast, BAV aneurysms were characterized by a relative lack of inflammation, preservation of elastin content, normal MMP-9 levels, and elevated MMP-2 expression. TIMP-1 and TIMP-2 levels were not significantly different among the three groups. CONCLUSIONS: Ascending aortic aneurysms exhibited increased MMP expression. The pattern of MMP expression and the degree of inflammation, however, differed between aneurysms associated with BAVs and those with TAVs. Variations in the molecular mechanisms underlying different types of thoracic aortic aneurysms warrant further investigation.     

Differing patterns of matrix metalloproteinase expression in patients with ascending aortic aneurysms and bicuspid aortic valves

Purpose: Abnormal matrix metalloproteinase (MMP) expression contributes to the development of infrarenal abdominal aortic aneurysms. Recent data have suggested that MMP-2 and MMP-9 may also play a role in thoracic aortic disease. We sought to determine whether the presence of a bicuspid aortic valve (BAV) had an impact on the pattern of MMP expression in ascending aortic aneurysms. Methods: Intraoperative samples of ascending aorta were obtained from 19 patients with ascending aortic aneurysms, 8 (42%) of which also had a BAV. Control samples of ascending aorta were obtained from 6 patients undergoing coronary artery bypass or organ donation/transplantation. None of the patients had aortic dissection or Marfan syndrome. Immunohistochemistry was used to identify expression of MMP-2 and MMP-9 within the aortic wall. Results: The frequency of MMP-2 expression did not differ between BAV patients (5/8, 63%) and non-BAV aneurysm patients (9/11, 82%; p = 0.6); MMP-2 expression was absent in the control group (0/6; p = 0.03 vs. BAV and 0.002 vs. non-BAV). MMP-9 expression, however, occurred rarely in both the BAV groups (1/8, 13%) and the control group (1/6, 17%; p = 1.0); positive MMP-9 staining was substantially more common in the non-BAV patients (7/11, 64%) than in the BAV group (p = 0.06). Conclusions: Ascending aortic aneurysms are associated with increased MMP-2 expression, regardless of the presence of a BAV. Increased MMP-9 expression, however, primarily occurred in aneurysms without a BAV. Variations in MMP expression patterns among different types of thoracic aortic aneurysms warrant further investigation.     

Single-stage repair of extensive thoracic aortic aneurysms: experience with the arch-first technique and bilateral anterior thoracotomy

BACKGROUND: Staged procedures for extensive aneurysmal disease of the thoracic aorta are associated with a substantial cumulative mortality (>20%) that includes hospital mortality for the 2 procedures and death (often from aortic rupture) in the interval between the 2 procedures. We have used a single-stage technique for operative repair of most or all of the thoracic aorta. METHODS: Forty-six patients with extensive disease of the thoracic aorta were managed with a single-stage procedure by using a bilateral anterior thoracotomy and transverse sternotomy, hypothermic circulatory arrest, and reperfusion of the aortic arch vessels first to minimize brain ischemia. Thirty-one patients with chronic, expanding type A aortic dissections had previous operations for acute type A dissection (n = 22), aortic valve repair or replacement (n = 4), coronary artery bypass grafting (n = 4), or no previous operation (n = 1). The remaining 15 patients had degenerative aneurysms (n = 12) or chronic type B dissections with proximal extension (n = 3). The ascending aorta and aortic arch were replaced in all patients combined with resection of various lengths of descending aorta (proximal one third [n = 19], proximal two thirds to three quarters [n = 22], or all [n = 5]). Coronary artery bypass grafting, valve replacement, or both were performed concomitantly in 19 patients. RESULTS: Hospital mortality was 6.5% (3 patients). Morbidity included reoperation for bleeding (17%), mechanical ventilation for more than 72 hours (42%), temporary tracheostomy (13%), and temporary renal dialysis (9%). No patient sustained a stroke. There have been 5 late deaths (3, 18, 34, 51, and 79 months postoperatively) unrelated to the aortic disease. Four patients have undergone successful reoperation on the aorta (false aneurysm [n = 1], endocarditis [n = 1], and progression of disease [n = 2]). Five-year survival was 75%. CONCLUSION: The single-stage, arch-first technique is a safe and suitable alternative to the 2-stage procedure for repair of extensive thoracic aortic disease.