Mechanical properties of the aneurysmal aorta.

The mechanical properties of the abdominal aorta were investigated non-invasively in 30 patients with aortic aneurysm and 11 with peripheral arterial disease. The distensibility of the aorta was measured using M-mode ultrasonography, permitting non-invasive assessment of the pressure--strain elastic modulus or aortic stiffness, Ep. The median Ep value increased from 4.0 N/cm2 in control subjects in their third decade of life (n = 10) to 10.4 N/cm2 in middle age (n = 11) to 14.0 N/cm2 in the elderly (n = 13). In the presence of a normal diameter, peripheral arterial disease with aortic atherosclerosis had little effect on aortic stiffness, median Ep being 16.0 N/cm2. Aneurysmal dilatation was associated with a significant increase in aortic stiffness, median Ep being 31.3 N/cm2 (P < 0.001). For aortas of normal diameter, Ep was at all ages dependent on mean arterial pressure. In patients with aortic aneurysms there was no clear relationship between Ep and mean arterial pressure or aortic diameter. Of the patients studied, 15 underwent aortic reconstruction; increasing aortic stiffness (log Ep) was associated with a decreased medial elastin content of the aortic biopsy (r = -0.63, P < 0.02). This study demonstrates the marked stiffness or inelasticity of dilated or aneurysmal vessels, part of which is attributable to the loss of elastin.     

Dissection of an aneurysmal ascending aorta in association with coarctation of the aorta.

A previously fit 21-year-old man presented with severel central chest pain. Clinical, electrocardiographic, and echocardiographic examination confirmed a dissection of an aneurysmal ascending aorta in the presence of previously undiagnosed severe aortic coarctation. Initial aortic dissection had occurred five days before admission. The medical and staged surgical management of the case are presented. Surgical survival with such a combination of lesions does not appear to have been previously recorded.     

A method of repair for asymmetric aneurysmal dilatation of the ascending aorta

The repair technique for an ascending aortic aneurysm depends on the portion of the aorta involved. An aneurysm in which the geometry of the sinotubular junction and the distal ascending aorta is preserved has classically been treated with resection and replacement with tube graft. We report an alternate method of resection of asymmetric aneurysmal dilatation of the ascending aorta with primary end-to-end anastomosis and our results of this approach with 14 patients. This method allows for complete resection of the aneurysm and tension-free anastomosis; it requires only one suture line and theoretically reduces the risk of bleeding. The endothelial surface of the aorta is preserved without an interposed synthetic graft. This method can be performed safely and the repair is durable at intermediate-term follow-up.     

A case report of compression of right pulmonary artery and bronchus by aneurysmal dilated ascending aorta in tetralogy of Fallot--suspension of ascending aorta

The patient was a 63-days-old boy who was admitted to our hospital because of moderate cyanosis and tachypnea. After admission, severe respiratory distress and emphysematous change of the right lung on the chest X-ray developed progressively. Echocardiogram and angiocardiogram demonstrated that a tetralogy of Fallot associated with right aortic arch and absence of pulmonary valve, and revealed remarkably dilated ascending aorta which compressed the right pulmonary artery and bronchus. Therefore, the emergency operation in that the ascending aorta was suspended to the 2nd rib was performed through a right thoracotomy. After surgery, his respiratory distress and emphysema of the right lung completely disappeared. To our knowledge, this is the 2nd reported case in which suspension of ascending aorta was successfully performed for pulmonary complication in congenital cardiovascular anomalies as this patient.     

Redo operations for recurrent aneurysmal disease of the ascending aorta and transverse aortic arch

Sixty-seven operations were performed in 59 patients for aneurysmal disease occurring after previous operations involving the ascending aorta and transverse aortic arch. The initial aortic pathological condition included the following: fusiform aneurysm due to medial degenerative disease in 34 patients, 12 of whom had Marfan's syndrome; aortic dissection in a previously undilated aorta in 23; and aneurysm persisting or occurring after brachiocephalic bypass in 2. One of the latter had an aneurysm because of aortitis. Various operations initially performed did not completely treat the disease, and certain complications occurred spontaneously, including infection and dissection. The residual pathological condition led to the development of aortic insufficiency, aortic dissection, coronary artery insufficiency, and progressive aneurysmal dilatation. These complications were treated by composite valve graft replacement of the aortic valve and ascending aorta or the transverse aortic arch or both, simple aortic valve replacement, graft replacement of the ascending aorta or arch or both, and suture of false aneurysm with viable tissue wrap. Twenty patients (34%) had an aneurysm of the distal aorta. The entire aorta was replaced in 3, thoracoabdominal segments in 9, and the abdominal aorta in 1. Of the 59 patients, 49 (83%) were early survivors and 40 (68%) were alive on January 1, 1985. Principles of therapy that may have prevented the complications leading to reoperation include aneurysm replacement at the time of aortic valve replacement and coronary artery bypass; total replacement of the ascending aorta and aortic valve in patients with Marfan's syndrome; the same procedure or aortic valve replacement and separate graft replacement in patients with non-Marfan's medial degenerative disease; ascending aortic replacement in all patients with dissection combined with valve resuspension, aortic valve replacement, or composite valve graft depending on the involvement of the aortic sinuses and the presence of aortic insufficiency.     

Valve sparing operation in a child with aneurysmal disease of the ascending aorta.

We describe an aortic valve-sparing operation in a small child with an ascending aortic aneurysm and root dilatation. The operation avoids the need for a prosthetic valve and long-term anticoagulation. Thus, the procedure is an attractive alternative for young children in whom a Ross procedure is not feasible.     

Spontaneous rupture of the ascending aorta

Background

Nontraumatic, spontaneous rupture of the ascending aorta is rare and the etiology is largely unknown.

Methods

We reviewed seven patients from our institution, with no known aortic disease or hereditary connective tissue disorder that presented with spontaneous ascending aortic rupture from 2012 to 2017.

Results

Most patients presented with non‐radiating chest pain along with hypertension (71.4%). The mean ascending aortic diameter at rupture was 4.60 ± 0.62 cm. The median door‐to‐operating room time was 2.58 h, resulting from effective implementation of an aortic emergency protocol. There were no operative mortalities.

Conclusions

In patients with ascending aortic rupture, aortic diameter may not always correlate with the risk of rupture. Rapid diagnosis combined with a multidisciplinary approach is vital for the successful management of these high‐risk patients.     

Spontaneous rupture of the ascending aorta

A case of non-traumatic rupture of the ascending aorta in an hypertensive patient is presented. The clinical findings suggested acute aortic dissection but the typical angiographic features of this entity were not found.     

Traumatic rupture of the ascending aorta

A 42-year-old male was diagnosed as having a traumatic rupture of the ascending aorta 24 hours after traffic accident. On admission, the patient was in a state of shock, but he was successfully treated by emergency surgery. Traumatic rupture of the ascending aorta is a serious condition and the mortality may be very high. Although physicians rarely encounter patients with this condition, it is relatively common among autopsy cases with multiple trauma. Urgent diagnosis and treatment are mandatory.     

Spontaneous rupture of the ascending aorta

A case of spontaneous non-traumatic rupture of the thoracic aorta in a hypertensive patient is presented. The clinical findings suggested acute aortic dissection, and a large pericardial effusion was detected by echocardiography. The typical angiographic features of aortic dissection were not found. Autopsy revealed a longitudinal intimal tear and a rupture in the postero-lateral aspect of the ascending aorta. No false lumen was seen in the ascending aorta. When acute intrapericardial or intrapleural bleeding develops with no evidence of aortic aneurysm or dissection, spontaneous aortic rupture should be suspected.     

Differential gene expression in human abdominal aorta: aneurysmal versus occlusive disease

OBJECTIVE: Inflammation and atherosclerosis are present in both abdominal aortic aneurysm (AAA) and arterial occlusive disease (AOD). Changes in gene expression that underlie the development of AAA versus AOD are poorly defined. This study evaluated differences in gene expression in AAA, AOD, and control aortic tissue with human gene array technology. METHODS: RNA was isolated from human aortic specimens (seven AAA, five AOD, and five control), and complementary DNA (cDNA) probes were generated. The cDNA probes were hybridized to a human cell interaction array of 265 genes and quantitated with phosphorimaging. The data were corrected for background and were standardized to housekeeping genes. Statistical differences in individual gene expression were determined with the Kruskal-Wallis test. RESULTS: Of 265 genes studied, 11 showed statistically different expression in diseased aorta as compared with control. The following three genes were downregulated in AAA: collagen VI alpha1 (P <.037), glycoprotein IIIA (P <.006), and alpha2-macroglobulin (P <.020). The following two genes were upregulated in AOD: laminin alpha4 (P <.034) and insulin-like growth factor 2 receptor (P <.049). The following three genes were upregulated in both AAA and AOD: matrix metalloproteinase-9 (MMP-9; P <.005), intercellular adhesion molecule-1 (P <.012), and tumor necrosis factor--beta receptor (P <.022). The following three genes were downregulated in both AAA and AOD: integrin alpha5 (P <.012), ephrin A5 (P <.037), and rho/rac guanine nucleotide exchange factor (P <.028). Of 16 MMPs evaluated, only MMP-9 was significantly (P <.005) upregulated in both AAA and AOD. Evaluation results of four tissue inhibitors of metalloproteinases showed no significant difference in expression for all tissue types, although tissue inhibitor of metalloproteinase-1 trended toward upregulation in AAA (P =.053). Eight of the fifteen most highly expressed genes in all the groups were extracellular matrix or secreted proteins. Of these, only collagen VI alpha1 (P <.037) showed a significant change, although biglycan trended toward downregulation in AAA (P =.076). CONCLUSION: This study used cDNA array technology in the comparison of human control and pathologic aortic tissue. Six genes had similar differential expression in both AAA and AOD as compared with control. Even more interesting were differences between AAA and AOD in the expression of five genes. These data suggest a similarity in genetic expression for both AAA and AOD, with altered expression of several genes playing a role in disease differentiation.     

Description and evaluation of a simplified technique for replacement of the ascending aorta and proximal arch in degenerative aneurysmal disease

The distal extension of ascending aorta pathology often requires prosthetic grafting into the proximal arch. In order to perform optimal distal anastomosis, an open technique under a short period of circulatory arrest (CA) was adopted. For this purpose we evaluated prospectively a simplified technique for surgery and perfusion. The aneurysmal aorta was directly cannulated to cool down the patient to 26 degrees C. Under CA and retrograde cerebral perfusion, the diseased aorta and aortic cannulation site were resected. After completion of the distal anastomosis, antegrade rewarming was performed via recannulation of the AAo graft (side branch graft) whilst surgery was proceeded on the root and/or aortic valve. This technique clearly addresses the safety of cannulation into the aneurismal aorta. The issues of cerebral and visceral protection during CA and antegrade reperfusion and rewarming have been analysed prospectively in eight patients operated on over a period of 6 months. Our preliminary results indicate that this technique of arterial cannulation and CA at 26 degrees C for the management of degenerative AAo disease involving the proximal arch appears safe both in terms of cerebral and systemic (visceral, muscular) protection. By this way, the complications related to deep hypothermia and prolonged cardiopulmonary bypass are avoided. This assumption may be only valid for a CA period less than 30 min. This preliminary study is limited by its small size and heterogeneity of the pathologies. However, the simplicity, surgical ease, rapidity and efficacy conveyed by this technique warrant further consideration and evaluation.     

Effect of aneurysm on the tensile strength and biomechanical behavior of the ascending thoracic aorta

BACKGROUND: Rupture of an ascending thoracic aortic aneurysm (ATAA), which is associated with significant mortality, occurs when the mechanical forces acting on the aneurysm exceed the strength of the degenerated aortic wall. The purpose of this study was to evaluate changes in biomechanical properties of the aortic wall related to ATAA formation. METHODS: Ascending thoracic aortic aneurysm tissue was obtained from surgery; control (nonaneurysmal) aorta was obtained from autopsy. Tissue strips with longitudinal (LONG) or circumferential (CIRC) orientation were stretched to failure. Maximum tissue stiffness and tensile strength were determined from plots of stress (normalized force) versus strain (normalized deformation). Student's t test was used for all comparisons. RESULTS: Tensile strength of LONG (nATAA = 17, n(control) = 7) and CIRC (nATAA = 23, n(control) = 7) ATAA specimens were 29% and 34% less than that of control tissue, respectively (p < 0.05). Maximum tissue stiffness was 72% stiffer for LONG ATAA (p < 0.05) and 44% stiffer for CIRC ATAA (p = 0.06) than for control tissue, respectively. CONCLUSIONS: The data suggest that ATAA formation is associated with stiffening and weakening of the aortic wall, which may potentiate aneurysm rupture.     

A large lipoma of the ascending aorta

Ascending aortic tumors are extremely rare. We describe a patient with a large lipoma of the ascending aorta, which was discovered after opening the pericardium for a surgical procedure for mitral regurgitation due to prolapse.