Proximal Aortic Dissection Research Articles

Proximal Aortic Dissection (Dissecting Aortic Aneurysm) in a Mature Ostrich

The gross and histopathologic lesions observed in a case of spontaneous proximal aortic dissection (dissecting aortic aneurysm) in a mature ostrich are reported. At necropsy, a dissecting intramural hematoma was seen in the proximal aorta, extended about 12 cm distally from the aortic valves. Histopathologic changes in aortic dissection included fragmentation and disruption of elastic laminae, presence of cystic extracellular spaces, and pooling of ground substance in the tunica media. Hepatic copper levels were measured, and the low concentration found suggested that a copper deficiency together with other risk factors such as the elevation of blood pressure may have been implicated in the development of the aortic dissection seen in this ostrich.

Proximal Aortic Dissection Late After Aortic Valve Surgery: 119 Cases of a Distinct Clinical Entity*

Besides systemic hypertension and Marfan syndrome, only previous aortic valve replacement (AVR) is independently associated with proximal (type A) aortic dissection. Little, however, is known to date about the characteristic features of this clinical entity. Clinical, prognostic and predisposing profiles in 119 cases of dissection and/or aneurysm occuring 1 month to 16 years after routine AVR were analyzed comprising 62 cases from our database and 57 reported cases. Dissection after AVR has been observed in 0.6% of all routine AVR procedures in the past four decades. With clinical signs, symptoms and anatomical features different from classic aortic dissection post-AVR dissection is a distinct clinical entity with a high intraoperative mortality of 44% and a 30-day and 5-year survival of 62% and 43%, respectively. Aortic regurgitation and a thin and/or fragile aortic wall at AVR, however, predict late dissection. Using a prediction model, the risk of late dissection can be stratified based on information obtained during AVR surgery. Aortic dissection following AVR is likely to represent a distinct clinical entity which can be predicted and possibly prevented at AVR.

Predictors of Proximal Aortic Dissection at the Time of Aortic Valve Replacement

Background —Type I aortic dissection develops in 0.6% of patients late after aortic valve replacement (AVR), and 13% of patients with type I aortic dissections have a history of AVR. Predictors of aortic dissection at AVR, however, have not been characterized. Methods and Results —A study group of 33 patients with type I aortic dissection had aortic surgery 49±55 months after routine AVR. A group of 101 controls, who did not have morphological progression of aortic diameters ≥6 years after AVR, was used to identify predictors of postsurgical dissection. Multivariate analysis identified aortic regurgitation ( P <0.002) and fragility ( P <0.001) or thinning of the aortic wall ( P <0.007) at AVR as predictors, associated with a 14%, 22%, and 7% probability of late aortic dissection, respectively. Clamping times, types of valve prostheses, concomitant coronary artery bypass grafting, and mean ascending aortic diameters of 43±10 mm at AVR did not predict late dissection. A separate analysis of 29 nondissecting aneurysms of the ascending aorta developing 104±64 months after routine AVR revealed younger age at AVR ( P <0.003) and congenitally bicuspid aortic valves ( P <0.03) as predictors of late aneurysm formation. Conclusions —Aortic regurgitation combined with fragile and thinned aortic walls in patients with moderate aortic dilation may reflect aortic root disease, with a high risk for postsurgical aortic sequelae if it is treated incompletely by isolated valve replacement.

Predictors of proximal aortic dissection at the time of aortic valve replacement.

Type I aortic dissection develops in 0.6% of patients late after aortic valve replacement (AVR), and 13% of patients with type I aortic dissections have a history of AVR. Predictors of aortic dissection at AVR, however, have not been characterized. A study group of 33 patients with type I aortic dissection had aortic surgery 49+/-55 months after routine AVR. A group of 101 controls, who did not have morphological progression of aortic diameters >/=6 years after AVR, was used to identify predictors of postsurgical dissection. Multivariate analysis identified aortic regurgitation (P<0.002) and fragility (P<0.001) or thinning of the aortic wall (P<0.007) at AVR as predictors, associated with a 14%, 22%, and 7% probability of late aortic dissection, respectively. Clamping times, types of valve prostheses, concomitant coronary artery bypass grafting, and mean ascending aortic diameters of 43+/-10 mm at AVR did not predict late dissection. A separate analysis of 29 nondissecting aneurysms of the ascending aorta developing 104+/-64 months after routine AVR revealed younger age at AVR (P<0.003) and congenitally bicuspid aortic valves (P<0.03) as predictors of late aneurysm formation. Aortic regurgitation combined with fragile and thinned aortic walls in patients with moderate aortic dilation may reflect aortic root disease, with a high risk for postsurgical aortic sequelae if it is treated incompletely by isolated valve replacement.

Leaking thoraco‐abdominal aortic aneurysm in Marfan syndrome

Marfan syndrome is a congenital disorder of the connective tissue involving the ocular, skeletal and cardiovascular systems. Cardiovascular complications account mainly for the reduced life expectancy of patients with Marfan syndrome. Thoracic aortic aneurysms usually occur as a result of proximal aortic dissection but aneurysms of the descending aorta are infrequent. We report on a patient with rupture of an extensive thoraco‐abdominal aortic aneurysm (Crawford type III) with a concomitant chronic thoracic aortic dissection (Stanford type A), treated successfully with aneurysmectomy and visceral artery reconstruction. Subsequent surgical intervention for the concomitant chronic thoracic aortic dissection was also performed. The importance of life‐long surveillance of the cardiovascular system is highlighted.

Periportal lymphatic distension resulting from cardiac tamponade: CT findings and clinical-pathologic correlation

Purpose: To correlate computed tomography (CT) findings with clinical-pathologic results and discuss the possible significance of periportal hypodensity in patients with clinical cardiac tamponade secondary to acute proximal thoracic aortic dissection, aneurysm, or heart rupture. Materials and methods: In a retrospective review of thoracoabdominal CT scans and records of 17 consecutive patients with hemopericardium, 10 patients with clinical signs of cardiac tamponade associated with hypodensity around the portal vein were selected; at surgery or autopsy all 10 patients had a thoracic aortic aneurysm, dissecting aneurysm, and heart rupture. The ratio of transverse inferior vena cava diameter to the diameter of the aorta at the level of the right adrenal gland was determined. Results: Abdominal CT scans showed focal (n = 1) or diffuse (n = 9) areas of hypodensity around the portal vein associated with pericaval hypodensity in four cases. Other abdominal abnormalities included persistent enhancement of renal parenchyma (n = 5), and gallbladder wall edema (n = 2); in nine cases the inferior vena cava diameter was significantly increased compared with that of patients with normal findings on CT scans (P < 0.01). Pathologic correlation, available in nine cases by autopsy, showed evidence of periportal lymphatic vessel dilatation and lymphedema. Conclusions: Periportal hypodensity on CT scans corresponds to the histopathologic picture of dilated lymphatic vessels or hepatic lymphedema; a diagnosis of hepatic lymphedema may be considered on the basis of CT scans in patients with pericardial effusion.

Experience with endovascular grafts in the treatment of infrarenal aortic aneurysms associated with proximal aortic dissection

BACKGROUND: Chronic abdominal and thoracic aortic dissections often present with concomitant infrarenal aortic dilatation. We conducted a retrospective review of 6 patients treated with endovascular stent grafts for coexisting aortic dissection and infrarenal aneurysm. METHODS: Six patients with suprarenal aortic dissections and infrarenal aortic aneurysms (AAA) had their AAAs treated with endovascular grafts. Grafts were constructed of balloon expandable Palmaz stents and expanded polytetrafluoroethylene graft. The device was inserted transfemorally and deployed under fluoroscopy. RESULTS: Successfully primary AAA exclusion was achieved in 5 patients. One patient required a supplemental stent placed above the endograft and into the true lumen to seal the endoleak. No aneurysm has enlarged, and all remain thrombosed for 9 to 24 months (mean 20). One type III dissection enlarged 2 weeks after endograft insertion. One patient had uncomplicated cephalad fenestration of a dissection by the endograft. CONCLUSIONS: Endovascular grafts may be used to treat coexisting AAA and aortic dissection. Attention to the site or sites of reentry of a dissection is essential to insure full aortic aneurysm exclusion. The fate of a chronic aortic dissection cephalad to an endovascularly treated AAA is unclear and will require longer follow-up.

Variations in annuloplasty ring and sizer dimensions may alter outcome in mitral valve repair.

Sizing the mitral annulus remains one of the more subjective areas of annuloplasty surgery. We compared the dimensions of annuloplasty rings to annuloplasty sizers and to human mitral valve annuli to determine whether any discrepancies exist that might impact repair results. The anterior and posterior length of rigid rings, flexible rings, and corresponding sizers were measured. The ratio of the anterior length to the total length was calculated (A/T ratio) and compared to normal human ratios. Nearly all rings had A/T ratios between 30% and 35% (except for the 32-mm rigid ring at 37.5%). For both rigid and flexible rings, the ring A/T ratios and the sizer A/T ratios differed significantly (except for the 28-mm rigid ring and sizer). In comparison to the average human A/T ratio (36.6%), the ratio for most rings was significantly lower. The mismatch between rings and sizers results in three possible scenarios: the length of the anterior portion of the ring can be equal to, smaller than, or larger than the anterior portion of the sizer. The clinical implications are that the valve could become stenotic when the ring is implanted or that the anterior portion of the annulus could be altered (stretched or buckled). We feel that to assure improved long-term results, more accurate matching of sizers to rings is essential and that better matching to normal human anatomical ratios would be ideal.

Proximal Aortic Dissection Complicated by Cardiac Tamponade.

Cardiac tamponade is a well recognized complication of acute proximal aortic dissection and is almost uniformly fatal if not immediately diagnosed and surgically treated. Pericardiocentesis has an ill-defined and perhaps deleterious role in the management of this condition. Severe concentric left ventricular hypertrophy and intravascular volume depletion may further impede ventricular filling in a patient with cardiac tamponade. We describe the management of a patient who presented in a confused state with an acute proximal aortic dissection complicated by cardiac tamponade and associated with evidence of left ventricular outflow tract obstruction. In such a patient, aggressive fluid administration and emergency surgery should be the treatment of choice.

Aortic manifestations and surgery in Marfan syndrome in pediatric patients

Aortic disease is a leading cause of morbidity and mortality in Marfan syndrome, both in the adults and children. Sequelae include congestive heart failure due to aortic regurgitation, endocarditis, aortic dissection, and sudden death due to aortic rupture. While aneurysms in Marfan syndrome can occur in any aortic segment and may also involve the major branch vessels, the aortic root is particularly predisposed. Recent advances in the diagnosis and the medical and surgical management of the aortic abnormalities of the Marfan syndrome have achieved a dramatic improvement in the quality of life and the life expectancy of affected individuals. Key features of the therapeutic protocol include reduction of aortic wall stress through the use of beta adrenergic antagonists, prevention of bacterial endocarditis, and early and serial applications of diagnostic imaging techniques to aid in the timing of prophylactic surgical intervention. The surgical repair of aneurysmal aortic dilatation or DeBakey type III aortic dissection is indicated in patients with symptoms indicative of impending rupture, ischemic complications related to dissection, or an aortic ratio of 2.0. Proximal aortic dissection requires aortic root replacement. In most cases, a composite valve graft is used to replace the aortic valve and ascending aortic segment. Biologic valve grafts may be particularly suitable for selected populations of pediatric patients. Postoperative management should include appropriate antibiotic prophylaxis, continued therapy with β-adrenergic antagonists, and diligent surveillance for new or recurrent aortic disease in both repaired and unrepaired segments. In combination, these therapies clearly diminish morbidity and contribute to a prolonged survival in the Marfan syndrome.

64-Year-Old Woman With Chest Pain and Presyncope

64-Year-Old Woman With Chest Pain and Presyncope

Cardiac tamponade complicating proximal aortic dissection. Is pericardiocentesis harmful?

Cardiac tamponade frequently complicates acute proximal aortic dissection and is one of the most common causes of death from aortic dissection. Well-defined strategies for the management of acute aortic dissection now exist; however, little is known about how best to manage the hemopericardium that may complicate it. Using a computer-based review, we retrospectively identified 10 patients presenting to our hospital over a 13-year period who were diagnosed with both aortic dissection and cardiac tamponade. All 10 had proximal dissections. Three of the 10 presented as the sudden onset of fatal electromechanical dissociation, 6 presented with hypotension, and 1 was normotensive on presentation. Of the 7 hypotensive or normotensive patients diagnosed with cardiac tamponade, 4 underwent successful pericardiocentesis while awaiting surgery. At time intervals of 5 to 40 minutes after their pericardiocenteses, 3 of the 4 patients experienced sudden onset of electromechanical dissociation and death; the fourth patient survived and underwent surgical repair. Of the 3 hypotensive or normotensive patients who had either no pericardiocentesis or an unsuccessful pericardiocentesis, all 3 underwent successful surgical repair and survived. In this study, patients with an aortic dissection complicated by cardiac tamponade have an early mortality of 60%. While 3 of the 10 died from electromechanical dissociation immediately upon presentation, the 3 other deaths all occurred shortly after successful pericardiocentesis, a procedure undertaken to stabilize them. While the number of patients in this series is small, the observations do raise the possibility that in patients with cardiac tamponade complicating aortic dissection pericardiocentesis could be harmful rather than beneficial. Possible mechanisms for why the performance of pericardiocentesis might destabilize such patients are proposed.

The Marfan syndrome: Cardiovascular physical findings and diagnostic correlates

Correlations among cardiac symptoms and auscultatory and phonoechocardiographic findings in Marfan syndrome have not been completely defined. A total of 24 patients with Marfan syndrome (16 men and 8 women; mean age 28.2 ± 8.6 years) were studied. Mitral valve prolapse was noted in 22, of whom 19 had either nonejection systolic click or mitral regurgitation murmur. Mitral regurgitation was noted in 12 patients by Doppler imaging. Aortic root dilatation was noted in 20 patients and aortic regurgitation in six, five of whom had aortic regurgitation murmur (5 of 20 patients had undergone surgery). Proximal aortic dissection was noted in two. Dyspnea (n = 12) was associated with progressive mitral or aortic regurgitation in four, but in the others dyspnea could not be explained by valvular or ventricular abnormalities. Chest pain was related to pneumothorax in five and aortic dissection in two but was not associated with either in 15 patients. palpitations (n = 12) and lightheadedness (n = 6) were not associated with specific arrhythmias. In conclusion, mitral valve prolapse and aortic root dilatation were the most common cardiovascular abnormalities in Marfan syndrome. Mitral valve prolapse was frequently associated with typical auscultatory findings and symptoms including dyspnea, chest pain, palpitations, and lightheadedness, whereas aortic root dilatation could be clinically silent unless complicated by aortic regurgitation or aortic dissection.

Acute myocardial infarction due to proximal aortic dissection in giant cell aortitis

Acute myocardial infarction due to proximal aortic dissection in giant cell aortitis

Proximal Aortic Dissection with Cardiac Tamponade: Long-term Survival without Surgery

Proximal aortic dissection in a 79-year-old woman was complicated by cardiac tamponade, aortic regurgitation, and pleural leak. Following pericardiocentesis and control of her hypertension, she survived without an operation for more than four years. Proximal aortic dissection in a 79-year-old woman was complicated by cardiac tamponade, aortic regurgitation, and pleural leak. Following pericardiocentesis and control of her hypertension, she survived without an operation for more than four years.

False-negative diagnosis of proximal aortic dissection by computed tomography or angiography and possible explanations based on transesophageal echocardiographic findings

Acute dissection of the thoracic aorta is a life-threatening disorder and early diagnosis is mandatory. Correct diagnosis must include the precise proximal origin of aortic dissection (AD) since patients with type I and II AD (DeBakey classification) usually require immediate surgery, whereas patients with type III AD can often be treated medically. 1 For the detection of AD, angiography, computed tomography (CT) and transesophageal echocardiography (TEE) are well established. 2–5 All these techniques may be associated with false-negative findings, that is, complete failure to visualize any AD at all or incorrect assessment of the proximal AD extension. We examine possible explanations for incomplete or false-negative AD diagnoses by CT or angiography using information provided by TEE studies.

Acute paraplegia: A presenting manifestation of aortic dissection

Two patients who presented with acute paralysis of the lower extremities as an initial manifestation of aortic dissection are described. The first patient had transient chest pain followed by flaccid paralysis of her lower extremities and severe back pain. In the second patient, sudden paralysis of both legs developed without pain of any sort. The paraplegia completely resolved in a few minutes; however, chest and back pain later ensued. Both patients had a proximal (type I or A) aortic dissection. The first patient's entrance tear in the aortic intima was just above the aortic valve with antegrade propagation, whereas in the second patient, the entrance tear was at the aortic isthmus, with both antegrade and retrograde dissection. Acute cardiac tamponade resulted in sudden deterioration and death in both patients, before any therapeutic intervention could be entertained.

Silent Aortic Dissection with Hemopericardium: Diagnosis by Computerized Tomography

An asymptomatic woman was evaluated because of a chest x-ray examination suggesting an aortic aneurysm. CT scan revealed proximal aortic dissection, which had apparently leaked into the pericardium. Increased use of CT scanning is expanding our knowledge of the clinical spectrum of aortic dissection.

Fatores de risco na cirurgia das dissecções da aorta ascendente e arco aórtico

A experiência cirúrgica no tratamento de 72 pacientes consecutivos com dissecções da aorta proximal foi analisada, com o objetivo de identificar os fatores agravantes do risco da operação. Trinta e nove pacientes foram operados na fase aguda e, em 9 pacientes, o comprometimento era restrito à aorta ascendente. O procedimento cirúrgico mais utilizado foi a substituição da aorta ascendente por tubo de Dacron, associada à correção da delaminação, tendo-se atuado no arco aórtico apenas em 5 pacientes. A mortalidade hospitalar foi de 27,7%, assumindo um valor de 43,5% para os pacientes operados na fase aguda e de 9% para os operados cronicamente. Em 45% desses pacientes houve uma relação direta entre a causa do óbito e a existência de complicações no pré-operatório. Foram considerados como determinantes de maior risco cirúrgico: as lesões neurológicas prévias, o tamponamento cardíaco, o choque cardiogênico, a isquemia miocárdica aguda e a disfunção renal. A compressão do tronco braquiocefálico, ou das artérias carótidas pela dissecção, o orifício de rotura primária da íntima no arco aórtico, a isquemia mesentérica e, nos casos operados na fase aguda, a insuficiência valvar aórtica de moderada ou grave repercussão também foram relacionados a um risco operatório mais elevado. Em conclusão, o resultado do tratamento cirúrgico das dissecções da aorta proximal guarda íntima relação com as condições pré-operatórias dos pacientes. A obtenção de melhores resultados com a operação na fase aguda depende, principalmente, do reconhecimento precoce da dissecção e da utilização de terapêutica clínica adequada durante o período de investigação diagnostica.

Carotid involvement in aortic dissection diagnosed by duplex scanning

Symptomatic carotid dissection following repair of a proximal aortic arch dissection has been successfully diagnosed by noninvasive ultrasonic duplex scanning. Angiographic confirmation, follow-up examinations by duplex scanner, and conservative management with heparin anticoagulation and tight blood pressure control are discussed. The differing etiologies and potential neurologic complications following aortic root dissection vs. spontaneous cervical carotid dissection are considered with a review of the current literature. Although diagnosis can be achieved through arteriography, the combined modalities of duplex scanning allow evaluation of both anatomic and hemodynamic factors. Conservative therapy may prove the most appropriate mode of management in these neurologically unstable patients.