Repeated failure of the suture line of an aortic valve prosthesis. Treatment by implantation of a valvular tube in the supra-coronary position

We present our 7 years' experience in the treatment of repeated stitch failure of the suture line on aortic valve replacements. We used a valved tube placed in the supra-coronary position. This technique prevented further stitch failure and also prevented postop infections. Of eight patients operated on, five had survived.     

Management of ascending suture line sepsis by excision on the ascending aorta and insertion of a left ventricular apex to aorta conduit.

A new technique used in the management of infection of an aortic suture line following aortic valve replacement and subsequent episodes of severe hemorrhage resulting from suture line disruption is described. In a planned, staged procedure, a left-ventricular-apex-to-aorta conduit was inserted followed by excision of the supracoronary aortic root and ascending aorta, incorporating all infected tissue. This technique demonstrates that near total excision of the ascending aorta is possible and coronary artery flow can be maintained with only a minimal supravalvular aortic chamber.     

A study of the junction between glutaraldehyde-treated allogeneic aorta and host aorta

BACKGROUND AND AIM OF THE STUDY: Stentless aortic valve bioprostheses have become popular because of their superior hemodynamics and expected increased durability. However, the stentless bioprosthesis differs from stented valves in that glutaraldehyde (GA)-treated tissue is implanted in direct contact with the native aorta. The effect of GA-treated tissue on host tissue has not been reported. METHODS: In order to analyze the effect of GA in the healing process, sheep descending aortic conduits treated with 0.625% GA were inserted in the descending thoracic aorta of 10 adult sheep. The implants were removed after 4, 5, 10, 12, 15, 25, 30, 32, 60 and 120 days. The upstream and downstream junctions were evaluated macro- and microscopically, and by immunohistology for smooth muscle cell alpha-actin and von Willebrand factor. RESULTS: By day 60 of implantation, the GA-treated conduits were calcified. By days 60 and 120, the calcification had spread to the host aorta, and was seen as foci of calcification in the junctional area. Acellular areas were also seen in the host aorta near the anastomosis. A fibrotic layer spanning the abluminal aspect of the junction between the implant and host aorta was present at day 4 and continued through 120 days. This layer was characterized by a progressive increase in collagenous matrix and cellularity, as well as new blood vessel formation. The luminal aspect of the junction had a neointimal layer of variable thickness containing alpha-actin-expressing cells covered by a monolayer of von Willebrand factor-expressing cells, seen at 15-30 days and present through 120 days. CONCLUSION: In our model, implanting GA-fixed tissue in direct contact with living tissues resulted in cell death and calcification of host tissue within 60 days. The integrity of the junction did not appear to be compromised. This may be of interest in light of the increased popularity of the stentless aortic bioprosthesis.     

Echocardiographic study of the morphology and growth of the aortic arch in the human fetus. Observations related to the prenatal diagnosis of coarctation.

BACKGROUND. In a study of normal and abnormal growth of the aorta before birth, high-resolution echocardiographic imaging of the aortic arch in 92 normal fetuses aged 16-38 weeks was used to establish normal values for aortic arch dimensions at varying gestational ages. METHODS AND RESULTS. From long-axis views of the aortic arch, the internal diameter of the aortic root, ascending aorta, transverse aortic arch, aortic isthmus, proximal descending thoracic aorta, and left common carotid artery were measured. Correlation coefficients for the diameter of each aortic arch segment when related to gestational age varied from r = 0.87 to r = 0.94 (p less than 0.001 for each), and growth curves were derived from the third and 97th percentiles around each linear regression analysis. In most of the fetuses, there was progressive tapering of the aortic arch, with the smallest diameter being at the isthmus. The ratio of the transverse aorta, isthmus, descending aorta, and aortic root to the ascending aorta remained relatively constant with gestational age, with mean values of 0.94, 0.81, 0.96, and 1.13, respectively. In five fetuses in whom a prenatal diagnosis of aortic coarctation was confirmed postnatally, transverse aortic and isthmic measurements fell on or below the third percentile for gestational age from the above data. In each case, the ratio of left common carotid artery to transverse aorta was greater than or equal to 0.73 compared with less than or equal to 0.62 for the 92 normal fetuses (mean ratios, 0.77 +/- 0.05 [SD] for coarctation versus 0.48 +/- 0.08 for normal fetuses; p less than or equal to 0.001). CONCLUSIONS. Use of normal growth curves for the developing aortic arch should facilitate the prenatal diagnosis of left heart and aortic arch abnormalities, particularly aortic coarctation, which until recently has been a difficult prenatal diagnosis to make with certainty.     

Is aortic dilatation an atherosclerosis-related process? Clinical,laboratory, and transesophageal echocardiographic correlates of thoracic aortic dimensions in the population with implications for thoracic aortic aneurysm formation

OBJECTIVES: The study determined, in a population-based setting, whether dilatation of the thoracic aorta is an atherosclerosis-related process. BACKGROUND: The role of atherosclerosis in thoracic aortic dilatation and aneurysm formation is poorly defined. METHODS: The dimensions of the thoracic aorta were measured with transesophageal echocardiography in 373 subjects participating in a population-based study (median age 66 years; 52% men). The associations between clinical and laboratory atherosclerosis risk factors, aortic atherosclerotic plaques, and aortic dimensions were examined. RESULTS: Age, male gender, and body surface area (BSA) jointly accounted for 41%, 31%, 38%, and 47% of the variability in diameters of the sinuses of Valsalva, ascending aorta, aortic arch, and descending aorta, respectively. Adjusting for age, gender, and BSA: 1) smoking was associated with a greater aortic arch diameter, and diastolic blood pressure and diabetes were each associated with a greater descending aorta diameter (p < 0.05); 2) atherosclerotic plaques in the descending aorta were associated with a greater descending aorta diameter (0.18 +/- 0.08-mm increase in diameter per 1-mm increase in plaque thickness; p = 0.02); and 3) minor negative associations were noted between atherosclerotic plaques and risk factors for atherosclerosis and the dimensions of the proximal thoracic aorta. Notably, atherosclerosis risk factors and plaque variables each accounted for <2% of the variability in aortic dimensions, adjusting for age, gender, and BSA. CONCLUSIONS: Age, gender, and BSA are major determinants of thoracic aortic dimensions. Atherosclerosis risk factors and aortic atherosclerotic plaques are weakly associated with distal aortic dilatation, suggesting that atherosclerosis plays a minor role in aortic dilatation in the population.     

A transmission line model of the normal aorta and its branches

A computer model of the aorta and its branches was made based on a simulation of an electrical transmission line using T elements. The model represented the aorta, with branches to the arms and legs and a branch to the head. The values for the capacitance and inductance of each T element could be specified, and a linearly increasing left ventricular pressure was used to drive the model. Transmission line equations were used to select values for the components, and an attempt was made to simulate the results of measurements of blood velocity in the aorta and peripheral arteries of normal subjects. The values obtained with the model showed a close relation to those in experimental studies. The results support the hypothesis that the arterial bed can be well represented by a "lossless" branched transmission line, with impedances matched at each branch and terminated with resistances that give a reflection coefficient of 0.5. A driving function, in which a linearly increasing left ventricular pressure provided a transient input to an aortic root of relatively low impedance, gave the best simulation of the experimental results.     

Relation of hemodynamics to the incidence of diethylstilbestrol-induced aortic ruptures in hypertensive and hypotensive lines of Turkeys

Hypertensive and hypotensive lines of turkeys were treated with diethylstilbestrol (DES) alone, or with DES and propranolol (PROP). Untreated turkeys of each blood pressure line served as controls. Mortality rate from aortic ruptures was highest (43.7%) in the hypertensive line treated with DES, but mortality was reduced to 7.7% when this line of turkey was treated with both DES and PROP. Among the hypotensive line of turkeys treated with DES, 26.7% died of aortic ruptures, but none died when these turkeys were treated with DES and PROP. Propranolol did not influence serum cholesterol levels, and all DES or DES and PROP treated birds had greatly elevated values, as contrasted to untreated turkeys. Aortic lipid values were highest in the hypotensive line of turkeys treated with DES, but, by histologic evaluation, aortic atherosclerosis was equally severe in all DES-treated turkeys. Blood pressure and aortic dp/dt max were higher in the hypertensive line treated with DES than in the similarly treated hypotensive line. This probably accounted for the higher mortality in the former group. Absence of significant mortality in either line of turkey following treatment with both DES and PROP apparently resulted from the decreased stress on the aorta caused by lowering of blood pressure and aortic dp/dt max by PROP.     

Pseudoaneurysm as a complication of the reconstruction of the ascending aorta using valved graft: periannular dehiscence simulating severe aortic insufficiency]

The development of a pseudoaneurysms of the ascending aorta is a potential complication after composite grafts surgery for combined disorders that simultaneously affect the aortic valve and ascending aorta. Pseudoaneurysm has been reported to range from 7% to 25% of cases, and it is due to dehiscence of the suture line at anastomosis. Clinical spectrum, which depends on the location of this dehiscence varies from the totally asymptomatic patient to one with NYHA class IV heart failure, with the possibility of its clinical status rapidly worsening. We report a case of progressive haemodynamic deterioration as a consequence of a peri-annular dehiscence that led to a significant regurgitant volume from the pseudoaneurysm cavity to the left ventricle mimicking a severe aortic insufficiency. The role of echocardiography is reviewed in the diagnosis and the management of complications, as well as the necessary follow up of patients with composite aortic grafts.     

Effect of removal of atherogenic diet on protein synthesis and cholesterol retention in rabbit aorta and lung

The purpose of these studies was to determine the effect of cholesterol feeding in rabbits on the synthesis of collagen and non-collagen proteins in both aortic and lung tissues. Rabbits were fed a 2% cholesterol diet for 30 or 60 days, followed by 30 days of a low cholesterol diet (i.e. 30-30 or 60-30). After 30 days of cholesterol feeding non-collagen protein synthetic rates were significantly elevated in aortic tissues, but not in the lung. After 60 days of cholesterol feeding, both collagen and non-collagen synthetic rates were elevated in the aorta but not in the lung. Both tissues demonstrated significant increases in cholesterol content. When cholesterol was removed from the diet, cholesterol continued to accumulate in the aorta but decreased in the lung. The 60-30 group demonstrated both the largest increase in aortic cholesterol, and the largest increase in the per cent of collagen being synthesized in the aorta. These data therefore demonstrate that cholesterol feeding stimulates both collagen and non-collagen protein synthesis and suggests that there may be some differences in the lag phase before significant changes are apparent in both parameters. Following removal of cholesterol from the diet the per cent collagen synthesized in the aorta increased further, due to an apparent reduction in non-collagen protein synthesis rather than a further acceleration of collagen synthesis. These changes may be important in explaining how intermittent-cholesterol feeding produces a more fibrous aortic lesion.     

Studies on aorta during development. I. Fetal rabbit aorta under ex vivo and in vitro conditions: rapid changes in smooth muscle cell phenotype, cell proliferation and cholesterol content with organ culture

The structural development of the already well defined fetal rabbit aortic wall from 22 to 31 days of gestation in vivo consists of increasing aortic wall thickness, elastic lamina continuities, extracellular matrix deposition, and maturing of the fine structure of the medial smooth muscle cells. In vivo at term (31 days), the mature aortic smooth muscle cells demonstrated the characteristic thin, thick and intermediate filaments, dense plaques, endoplasmic reticulum, golgi, plasmalemma vesicles and an incomplete basal lamina. The fetal aorta rapidly responded to organ culture with various changes. Fetal smooth muscle cells modified their phenotype to the synthetic state when cultured in both serum-supplemented and serum-free media. This smooth muscle cell modification occurred after 3 days of culture in fetal explants. The synthetic type smooth muscle cells (fetal) began to proliferate after 6 days of culture. This proliferation resulted in a peripheral outgrowth after 9 days of 10-20 layers in fetal cultures from serum-supplemented media and of 2-4 layers in serum-free media. The orderly arrangement of the internal elastic lamina and alternating medial layers of smooth muscle cells and elastic lamina seen in vivo was disrupted along with increased matrix after 9 days of fetal explant culture. Significant numbers of 'modified' synthetic phenotype smooth muscle cells were not observed in adult aortic explants until after 15 days in culture in serum supplemented media. The mature contractile phenotype smooth muscle cell predominated in adult explants cultured in serum-free media. Significant synthetic phenotype smooth muscle cell proliferation only occurred in adult explants after 15 days culture in serum-supplemented media. When compared to aorta in vivo evidence for increases in cholesterol esterification were observed in both fetal (9 days) and adult (15 days) explants cultured in both serum-supplemented and serum-free media. The fetal aorta in organ culture appeared to be more susceptible than the adult aorta to (a) phenotypic modulation of smooth muscle cells to the synthetic state, (b) smooth muscle cell proliferation, and (c) early cholesteryl ester accumulation.     

Aortic dissection presenting as pericarditis

In five patients with aortic dissection, signs and/or symptoms of pericarditis were part of the early manifestations of the aortic disease. Signs of inflammatory pericarditis were noted clinically in four patients and were found at autopsy in one. In the three nonoperated patients who died of aortic rupture leading to fatal hemopericardium, symptoms of pericarditis preceded fatal rupture of the aorta by four to five days. A fourth patient died after surgical repair of aortic dissection 35 days after the onset of pericarditis. In the fifth patient, manifestations of chronic constrictive pericardial disease occurred over a period of seven months after which old aortic dissection was first identified. In each case, the internal tear of classic aortic dissection was located in the ascending aorta. Microscopic evidence of cystic medial necrosis of the aorta was present in each case. In each of two cases, there was a congenital bicuspid aortic valve. The phenomenon observed represents acute aortic dissection in which slow penetration of blood into the pericardial space caused inflammatory pericarditis. The interval between the onset of pericarditis and rupture of the aorta may allow sufficient time for appropriate diagnosis and potentially lifesaving treatment of the aortic disease.     

Cross-sectional echocardiographic detection of aortic obstruction. 2. Coarctation of the Aorta

Cross-sectional echocardiographic studies of the aortic arch and proximal descending aorta were performed in 18 patients with coarctation of the aorta and 20 normal subjects. In normals the aortic arch and proximal descending aorta appeared as an arcuate, echo-free structure curving across the plane of the scan. There were no localized changes in aortic diameter and the amplitude of aortic systolic pulsation was symmetrically maintained throughout the scan plane. Visualization of this region was possible in 16 of 18 patients with coarctation. In each of these cases there was a localized area of decrease in aortic diameter in the region of the left subclavian artery which corresponded to the angiographic appearance of the coarctation. In addition prominent systolic pulsation of the aortic arch proximal to the region of obstruction was evident. Cross-sectional echocardiography may offer a useful noninvasive method for direct visualization of aortic coarctation.     

Bicuspid aortic valve morphology when associated with coarctation of the aorta

Thirteen children and young adults with coarctation of the aorta as their principal cardiovascular abnormality, 11 with bicuspid aortic valves, were evaluated by orifice-view aortography to evaluate their aortic valvular morphology. For comparison 30 individuals with aortic valvular deformities but without coarctation of the aorta were similarly studied. Two distinct forms of bicuspid valves could be identified characterized by either the appearance of gross inequality of size of the two valve leaflets or an appearance wherein each leaflet closely approximated the size of the other, thus equally bicuspid. Excepting two individuals with normal, tricuspid, aortic valves, all of the patients with coarctation of the aorta had equally bicuspid aortic valves which contrasted to the group without coarctation in which the unequally bicuspid type predominated. This difference in bicuspid aortic valve morphology associated with coarctation of the aorta suggests a different developmental process involving the aortic valve as opposed to the situation in individuals without coarctation.     

Dynamic aortic obstruction in a patient with acute type B dissection

There are at least 7000 aortic dissections diagnosed in the United States each year. Type B dissections accounted for 38% of cases enrolled in the prospective International Registry of Aortic Dissection. We report a case of a 48-year-old hypertensive woman with an acute type B aortic dissection causing significant dynamic obstruction of the aorta. Intravascular ultrasound of her aorta revealed a mobile intimal flap nearly obliterating the true lumen with each systolic contraction. Simultaneous pressure tracings obtained from her ascending aorta and femoral artery demonstrated a systolic pressure gradient in excess of 100 mm Hg. The patient developed progressive renal failure and ultimately underwent successful operative replacement of the proximal descending thoracic aorta with a Dacron graft. In this case presentation, we highlight the unusual physiology exemplified by this case and explore contemporary management strategies for complicated type B aortic dissection, including surgery and catheter-based techniques.     

Aortic aneurysm after patch aortoplasty repair of coarctation: a prospective analysis of prevalence, screening tests and risks

Twenty-nine children were evaluated prospectively for the presence of an aortic aneurysm at the repair site 1 to 19 years after patch aortoplasty repair of coarctation of the aorta. In each child, noninvasive evaluation included a chest X-ray film, computed tomography of the chest and two-dimensional echocardiography. The presence and size of an aortic aneurysm were determined quantitatively by measuring the ratio of the diameter of the thoracic aorta at the repair site to the diameter of the aorta at the diaphragm (aortic ratio). An aortic ratio of greater than or equal to 1.5 was judged abnormal and was shown to be significantly greater than the aortic ratio of a normal control group. An aortogram was obtained in each child if any noninvasive screening test was found to be abnormal. As assessed by the aortogram, the prevalence of aortic aneurysm was 24% in this patient group. The sensitivity of echocardiography and chest computed tomography for detecting an aneurysm was 71% and 66%, and the specificity 76% and 85%, respectively. The chest X-ray film was 100% sensitive and 68% specific in determining the presence of an aneurysm. Although the data are not statistically significant, they suggest that children undergoing patch aortoplasty as the primary procedure (rather than a reoperation after earlier resection), and children in whom a Dacron patch is utilized may be at increased risk for aneurysm formation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Two-dimensional echocardiographic findings in postoperative aortic suture line endarteritis

Infections occurring after aortic valve surgery, whether valvuloplasty or replacement, commonly affect the valve itself. However infection of the aortic suture line alone is extremely rare. Such cases with endarteritis can be diagnosed at autopsy or by angiocardiography. In this report a patient with a vegetation at the aortic suture line which was diagnosed by echocardiography is presented. By two-dimensional echocardiography, a very mobile and echo-dense mass protruding from the ascending aorta was observed on the recordings through the suprasternal notch. This diagnosis was surgically confirmed and the patient was treated.     

Body perfusion in surgery of the aortic arch

We propose a new cannulation and perfusion technique for aortic arch surgery, in order to achieve continuous antegrade total-body perfusion under moderate hypothermia.The heart and the aortic arch are exposed through a median sternotomy. Cardiopulmonary bypass is established from the right atrium to the right axillary artery. At 26 degrees C of body temperature, the supra-aortic vessels are clamped, the ascending aorta and the aortic arch are incised, and a cuffed endotracheal cannula, connected to an arterial line geared by a separate roller pump, is inserted into the descending thoracic aorta. Perfusion is started in the distal body, while the brain is perfused through the right axillary artery. Once the aortic arch has been replaced with a Dacron graft and the supra-aortic vessels have been reimplanted on the graft, the arterial line in the descending thoracic aorta is clamped and removed. The supra-aortic vessel clamps are removed, the proximal part of the Dacron graft is clamped, and systemic cardiopulmonary bypass is resumed via the right axillary artery.From January 2002 through December 2005, this technique was used in 12 consecutive patients on an emergency basis, due to acute aortic dissection that required total arch replacement. Within the first 30 postoperative days, 1 patient (8.3%) died, and no patient had permanent neurologic deficits.This simple technique ensures a full-flow antegrade total-body perfusion during all phases of the surgical procedure, thereby eliminating ischemia-reperfusion syndrome and yielding excellent clinical results.     

Turner's syndrome and cardiovascular anomalies: a case report and review of the literature

Turner's syndrome is a genetic disease in which many cardiovascular anomalies have been reported, coarctation of the aorta being the most frequent. The most serious complication that can arise from these abnormalities is aortic dissection. The authors present an unusual case of Turner's syndrome with an aortic sinus aneurysm and severe aortic insufficiency in the absence of coarctation of the aorta. The various cardiovascular anomalies seen in Turner's syndrome, such as coarctation of the aorta, bicuspid aortic valve, aortic dissection, aortic sinus aneurysm and ascending aorta aneurysm, can best be understood on a common basis of congenital structural abnormalities involving the aorta and the aortic valve. The only evidence available for such an abnormality is the presence of cystic medial necrosis in the affected vascular tissues.     

Aortitis

Inflammatory or noninfectious aortitis may be idiopathic or it may be part of a systemic autoimmune disease, such as Takayasu's arteritis, Beh?et's disease, or giant cell arteritis. At the acute stage, there is thickening of the aortic wall with dilatation of the aorta, more commonly in the thoracic aorta. If it involves the aortic root, there may be annuloaortic ectasia or aortic regurgitation. At a later stage, there may be aneurysmal dilatation of the aorta and rarely dissection or rupture of the aorta. In Takayasu's arteritis, stenosing lesions can occur as well as aneurysmal dilatation of the aorta or arteries. Stenosing lesions may be treated with angioplasty with or without stenting, whereas aneurysmal dilatation of the aorta is treated by aneurys-mectomy with arterial reconstruction or conduit. Severe aortic regurgitation may require aortic valve surgery with or without replacement of the ascending aorta. Irrespective of the interventional procedure undertaken as appropriate for the lesion, control of inflammation with steroid therapy with or without other immunosuppressive agents is of paramount importance. Otherwise, prosthetic valve or graft dehiscence may occur after aortic surgery, and restenosis rate is also higher after percutaneous transluminal angioplasty or stenting.     

Aortic insufficiency in Takayasu's disease. Apropos of 3 surgically treated cases and review of the literature

The author report the cases of three women with aortic regurgitation associated with aneurysmal dilatation of the ascending thoracic aorta. Aortic valve replacement was carried out in the 3 cases, with resection of the aortic aneurysm in 2 cases. Histological examination of the aortic wall in all 3 cases showed non-specific aortitis in the adventitia and media, appearances comparable to those described in Takayasu's disease. The incidence of aortic regurgitation in Takayasu's disease is about 10%. These 3 cases are compared with 30 other cases with histological confirmation in the medical literature, only 9 of which have undergone aortic valve replacement. The mechanism of the aortic regurgitation is analysed: dilatation of the aortic ring, inflammation of the valve cusps, commissural dysjunction or dilatation of the ascending aorta involving the line of commissural insertion. Aortic regurgitation is usually associated with other arterial localisations of the disease, but may also be found alone when the disease seems limited to the ascending aorta. Coronary artery disease, especially ostial, is observed in 30% of patients with this type of aortic regurgitation. Coronary angiography is therefore mandatory before surgery. The arterial involvement may be investigated initially and followed-up by 2 non-invasive investigations = digitalised intravenous angiography (DIVA) and M mode and 2D echocardiography. The two investigations give comparable results with regards to the study of the aorta, but the branches of the aorta and pulmonary arteries can only be investigated by DIVA.(ABSTRACT TRUNCATED AT 250 WORDS)