Intramural aortic dissection

OBJECTIVE: To investigate possible associations between tobacco smoking and alcohol consumption and the risk of adult glioma. DESIGN: This was a population based, case-control study. Relative risks (RR) were estimated using logistic regression analysis. SETTING: Melbourne, Australia. PARTICIPANTS: These comprised 416 case subjects (166 women, 250 men), 66% of those eligible; and 422 control subjects (170 women, 252 men), 43.5% of those potentially eligible. RESULTS: There was no increase in risk of glioma with having ever smoked tobacco (RR 1.29, 95% CI 0.95, 1.75) for all subjects, adjusted for age, a reference date, and gender. There was a slight increase in risk for men (RR 1.64, 95% CI 1.1, 2.45), but not for women (RR 0.99, 95% CI 0.62, 1.62). For men, there was no increase in risk with increasing pack-years of cigarette smoking, but the risk was significantly increased in subjects who had smoked for less than 10 years. There was no increase in risk associated with having ever drunk alcohol for all subjects (RR 0.96, 95% CI 0.67, 1.37), women (RR 0.69, 95% CI 0.4, 1.15) or men (RR 1.40, 95% CI 0.81, 2.43). CONCLUSIONS: This study does not support an association between either tobacco smoking or alcohol consumption and glioma. The pattern of risk associated with tobacco smoking in men appears inconsistent with a causal role, and may be due to chance, response bias, or uncontrolled confounding.     

Imaging of thoracic aortic dissection

Acute thoracic aortic dissection has a high mortality if untreated, so the diagnosis must be rapidly made if mortality is to be lowered significantly. Multiple imaging techniques are often used. This retrospective study from 1988 to 1993 assesses the usefulness in diagnosis of chest X-rays, computed tomography (CT) scanning, aortography, magnetic resonance imaging (MRI), trans-thoracic (TTE) and trans-oesophageal (TOE) echocardiography. Forty-two patients with a final clinical diagnosis of dissection were studied. The diagnosis was confirmed in 16 (13 at surgery and three at autopsy). Three died with dissection given as the only cause for death. Chest X-ray abnormalities were seen in all 19 patients with surgery or death from dissection, with a widened mediastinum and/or dilated aorta being present in 17. In the group of 16 patients with surgery or autopsy proof, CT scans found dissections in 9 of 12 patients studied and correctly classified the type in only five. Aortography was performed in five, with accurate depiction of dissection and type in all. TTE found dissections in three of eight patients imaged by this method. MRI and TOE were performed each on two patients, with accurate depiction of dissection and type in each. Because of the relatively low sensitivity of CT scanning in defining aortic dissections Westmead Hospital is currently assessing the use of TOE as the prime imaging modality prior to surgical intervention.     

Echocardiographic diagnosis of the dissection of the thoracic aorta

Nine patients with aortic root dilatation without dissection and four patients with a dissecting aneurysm of the ascending aorta were studied with single-plane echocardiography. Previously reported echocardiographic findings, which have been shown to be similar in these two groups of patients, are confirmed. In addition to (a) aortic root dilatation, (b) thickening of the anterior and/or the posterior aortic wall, and (c) the multiple parallel echoes within the widened aortic walls, which are all considered to be not specific signs of dissection, the authors outline the presence of some specific echocardiographic patterns in patients with a dissecting hematoma of the ascending aorta. These include: 1) the loss of contiguity between the inner borders of the anterior aortic wall and the interventricular septum when the dissection is confined to the anterior wall of the aorta; 2) the loss of contiguity between the inner and/or outer borders of the posterior aortic wall and the mitral anulus if the hematoma extends to the posterior wall of the aorta.     

Abdominal aortic resection in thoracic dissection

Dissection nearly always begins in the thorax, but it commonly extends into the abdominal aorta, which may become the focal point of the disease. We report five patients who illustrate the surgical management of this disease variant. Clinical manifestations included retroperitoneal rupture, expanding false aneurysm, and lower aortic occlusion. All patients had an aortic bifurcation graft, with reentry of the false lumen at the renal level. Two patients also had thoracic-aortic resection or plasty or both. Although one patient had thoracic aortic rupture at the five-year interval, these abdominal aortic resections provided effective palliation in all. This successful experience in managing complex dissections shows that when aortic dissection extends into the abdomen, resection of the distal aorta with a reentry procedure may be appropriate therapy.     

Haustration of the ascending aorta as differential diagnosis of aortic dissection

Clostridium perfringens isolated from sheep and goat with enterotoxaemia at necropsy and from healthy animals at slaughter were typed using specific PCR assays for the detection of the alpha-, beta- and epsilon-toxin genes. Clostridium perfringens isolated from all 52 animals with pathological signs of enterotoxaemia showed the presence of the alpha- and epsilon-toxin genes but were devoid of the beta-toxin gene. These strains could therefore be identified as type D, characteristic for clostridial enterotoxaemia of sheep, lambs and goats. In contrast, Cl. perfringens isolated from 11 of 13 healthy animals only contained the alpha-toxin gene which is typical for type A. Two of the healthy animals contained Cl. perfringens with the alpha- and epsilon-toxin genes. However, when several individual Cl. perfringens colonies were analysed from each of these two animals, only a small percentage was found to contain the epsilon-toxin gene, whereas the majority of the colonies were of type A with the alpha-toxin gene only. This is in contrast to the findings from the diseased animals which contained practically only type D Cl. perfringens. The beta-toxin gene was not found in any Cl. perfringens isolate from goat and sheep. Comparison of the PCR data with results obtained by the classical biological toxin assay using the mouse model showed a good correlation.     

Chronic dissection of the thoracic aorta in a patient with tuberculous pleuro-pericarditis

The production of mycotoxins by Alternaria alternata in cellulosic ceiling tiles was examined with thin-layer chromatography and high-performance liquid chromatography procedures. Alternariol and alternariol monomethyl ether were found in ceiling tile extracts, whereas extracts of control rice cultures of all three isolates produced these mycotoxins plus altenuene and altertoxin I. Extensive fungal growth and mycotoxin production occurred in the ceiling tiles at relative humidities of 84-89% and 97%.     

CT diagnosis of an unusual aortic dissection with intimointimal intussusception: the wind sock sign

A unique combination of CT findings is reported in a rare case of aortic dissection with intimointimal intussusception. The CT showed a wind sock-like appearance in the contrast column of the aortic arch, which was felt to be characteristic of the intussuceptum. Complementary CT findings, including proximal flap in the dilated root of the aorta, no mid-ascending aortic flap, a descending aortic flap, and pericardial effusion, enabled establishment of the preoperative diagnosis.     

A new radiographic sign of acute traumatic rupture of the thoracic aorta: displacement of the nasogastric tube to the right

Numerous plain chest radiographic signs previously described for the diagnosis of acute traumatic rupture of the thoracic aorta may be present in patients with or without such rupture. Displacement of an opaque nasogastric tube to the right (indicative of esophageal displacement) has been found to be the most reliable sign for the diagnosis of this condition, and may be used as an indication for emergency aortography.     

Intermittent cocaine use associated with recurrent dissection of the thoracic and abdominal aorta

Acute aortic dissection has been reported with the use of cocaine. We report a case of intermittent cocaine use spanning nearly 5 years and leading to recurrent dissection and extension of the false lumen. The patient repeatedly declined surgical correction. Management involved aggressive pharmacologic blood pressure control, close monitoring, and encouragement to enter drug rehabilitation.     

Aorto-atrial fistula associated with recurrent aortic dissection after ascending aorta replacement

A case of bilateral congenital aplasia of the carpal scaphoid bone is presented. In contrast to previously reported cases of congenital hypoplasia of the scaphoid, this case was not associated with hypoplasia or absence of thenar and forearm muscles, absence of the sesamoid bones of the thumb, abnormalities of the skeleton of the thumb ray or hypoplasia of the forearm bones.     

Long-term results of the surgical treatment of acute type A thoracic aortic dissection

Out of a population of 110 patients operated as an emergency for acute Stanford type A dissection of the thoracic aorta between 1985 and 1994, there were 84 survivors. Seventy-nine were assessed after a mean follow-up period of 47.3 months. The corrected 1 year, 5 year and 10 year survival rates were 69 +/- 5.1%, 53.1 +/- 6% and 42.1 +/- 7.1% respectively. There were 19 deaths during the study period: in two thirds of cases death was due to cardiovascular complications related to the aortic pathology or hypertension. There were 13 reoperations in 12 patients for complications on the initial site of repair or for progression of the pathological process. The average time to reoperation was 21.5 months with an operative mortality of 3 patients (25%). Predictive factors of reoperation were young age (52 +/- 4.4 years vs 60.1 +/- 1.4 years; p = 0.037), the persistence of a patent false lumen (p = 0.033) and the initial surgical techniques as the incidence of reoperation seemed to be higher after treatment with biological glue alone or resuspension of the aortic valve compared with replacement of the ascending aorta or Bentall's procedure (p = 0.08). The incidence of reoperation also varies with time as it was 1.8 +/- 0.7% at 1 year, 18.5 +/- 6.5% at 5 years and 26% +/- 7.8 at 10 years. In spite of improvements in surgical technique and postoperative care, acute type A dissection of the aorta carries a poor prognosis in both the short and the long-term with a notable number of cardiac or other complications related to repair of the initial aorta. Analysis of these and other reported results suggest that initial surgery should be as complete as possible with extension to the aortic arch when involved: this more aggressive attitude should improve the long-term results by reducing the risk of reoperation responsible for a high mortality rate.     

Rupture of an abdominal aortic aneurysm following acute descending thoracic aortic dissection. Case report

The coexistence of an abdominal aortic aneurysm and an acute aortic dissection seems to be rare and only a few reports are to be found in the literature. We report a case of a patient with acute aortic dissection of the descending thoracic aorta that caused rupture of a pre-existing abdominal aortic aneurysm. The literature is also thoroughly reviewed.     

A rare presentation of thoracic aortic dissection as detected by transoesophageal echocardiography

Sex-based differences in serum leptin concentrations have been reported in adolescence and adulthood. To discover when such differences were generated, serum leptin concentrations were measured in umbilical cord blood from 46 healthy infants and in the mother's blood at delivery. Considering the respective body weights of the mothers and infants (68.5 +/- 1.3 kg and 3.3 +/- 0.0 kg), umbilical cord concentrations of leptin were disproportionately high in the infants (9.4 +/- 1.2 micrograms/l) compared with those in the mothers (18.7 +/- 1.3 micrograms/l). There was a wide variation in the infants leptin values (1.2 +/- 56.8 micrograms/l) that did not correlate with height, weight, cephalic circumference, or any other growth-related parameter. The most striking differences emerged when results were analysed by sex: umbilical cord concentrations of leptin in the girls (12.9 +/- 2.2 micrograms/l) were significantly (P < 0.01) greater than those in the boys (6.8 +/- 0.9 micrograms/l), although no differences in leptin concentrations were observed between the mothers who gave birth to a girl (19.5 +/- 2.2 micrograms/l) and those who gave birth to a boy (18.1 +/- 1.7 micrograms/l). The sex-based differences were not attributable to any growth-related differences between the sexes, except heavier placental weights in the girls (P < 0.007) than in the boys. These differences in leptin concentrations may reflect a sex-based difference in the regulation of leptin production by the fetal adipose tissue.     

Acute dissection of the thoracic aorta: experience at the Puerto Rico Medical Center (1991 through 1995)

BACKGROUND: Acute dissection of the thoracic aorta has a very poor prognosis unless promptly diagnosed and treated. The clinical presentation, diagnosis and management of 16 patients was reviewed. METHODS: We identified 12 patients from the Puerto Rico Medical Center and 4 patients from the "Centro Cardiovascular de Puerto Rico y del Caribe" whose diagnosis was made from January 1991 to December 1995. Medical records and autopsy reports were reviewed. RESULTS: Of the 16 patients, 10 [62%] were males, 10 [62%] were 60 years old or older [range 25 to 85 years], and 15 [93%] had a past history of hypertension although only 6 [38%] were found with an initial blood pressure of 140/90 or higher. Chest pain was the initial symptom in 13 [81%]. Of these 46% [6/13] described it as oppressive, with radiation to back or neck in 38% [5/13]. In none a neurological abnormality was the initial presentation. No physical sign was present in more than 40% of patients. One patient had a diastolic murmur suggestive of aortic regurgitation but none had a pericardial rub or a neurologic deficit. The electrocardiogram showed left ventricular hypertrophy in 35% but none had changes compatible with an acute Q wave infarction. The chest radiography was compatible with dissection in all in whom it was done [8/8]. Computerized tomography of the chest was diagnostic in 6 of 8 patients [sensitivity 75%]. Aortography had a sensitivity of 80% [4/5]. Trans-thoracic echocardiogram was diagnostic in 3 of 4 patients [75% sensitivity]. Transesophageal echocardiogram had a 100% sensitivity [2/2]. In 8 patients [50%] the correct diagnosis was made by postmortem examination, all of whom died within 24 hours of Emergency Room's evaluation. Of those properly diagnosed 5 died without being surgically intervened. Only one survived surgery [1/3] Overall mortality was 93%. The most common pathological finding was Type A dissection in 14 [88%]. Cardiac tamponade was found in 9 [56%]. Hemothorax was found in 6 [38%]. Aortic valve insufficiency was reported in 20% and coronary artery involvement in 28%. CONCLUSIONS: The dismal prognosis traditionally associated with acute dissection of the thoracic aorta remains unchanged. Prompt diagnosis based on high clinical suspicion. followed by expeditious medical and surgical treatment are fundamental to change the natural course of this condition.     

New approach to aortic dissection: development of an insertable aortic prosthesis

We have developed a new aortic prosthesis with which we can replace or reinforce the aorta using a simple percutaneous technique. We have named the new prosthesis the shape-memory aortic prosthesis (SAP); it consists of a spiral-shaped nitinol stent and polyurethane tube. It can be compressed inside a 14F catheter at a low temperature and regain its original shape at above 30 degrees C. As a preliminary study, SAP sutureless grafting into the descending aorta was performed on 10 mongrel dogs. We found that when the proper diameter of SAP was applied, it functioned satisfactorily for 3 months or more. A percutaneous placement technique pertinent to the SAP also was developed and tried on 4 animals. Our procedure was applied to Stanford type B dissection models to close the entry point successfully. This newly developed SAP has potential to be applied to emergency cases of human aortic dissections.