Anomalous origin of the left coronary artery from the pulmonary artery in an adult: tubular reconstruction of the left main coronary artery under coronary perfusion

Structural modelling of the cardiovascular system

Computational modelling of the cardiovascular system offers much promise, but represents a truly interdisciplinary challenge, requiring knowledge of physiology, mechanics of materials, fluid dynamics and biochemistry. This paper aims to provide a summary of the recent advances in cardiovascular structural modelling, including the numerical methods, main constitutive models and modelling procedures developed to represent cardiovascular structures and pathologies across a broad range of length and timescales; serving as an accessible point of reference to newcomers to the field. The class of so-called hyperelastic materials provides the theoretical foundation for the modelling of how these materials deform under load, and so an overview of these models is provided; comparing classical to application-specific phenomenological models. The physiology is split into components and pathologies of the cardiovascular system and linked back to constitutive modelling developments, identifying current state of the art in modelling procedures from both clinical and engineering sources. Models which have originally been derived for one application and scale are shown to be used for an increasing range and for similar applications. The trend for such approaches is discussed in the context of increasing availability of high performance computing resources, where in some cases computer hardware can impact the choice of modelling approach used.

Sudden death due to aortic dissection in early pregnancy - a case report

Forensic pathologists come across many deaths due to natural causes which are sudden. Sudden natural deaths in females who are pregnant warrant thorough investigation and a medico-legal autopsy to rule out any foul play. Here, we report a case of 21-year-old primigravida in her first trimester who suddenly complained of severe chest pain and was brought dead to the hospital with no history suggestive of prior natural disease. At autopsy, the death was attributed to dissection of ascending aorta.

Gore TAG®Thoracic Endoprosthesis: the first US FDA-approved thoracic endograft

Open surgical repair of thoracic aortic lesions carries a significant risk of complications, including death. Minimally invasive approaches, however, may improve outcomes. Clinical trials of the Gore TAG Thoracic Endoprosthesis device indicate that subjects receiving the graft are less likely to experience major adverse events, less intraprocedural blood loss, shorter intensive care unit and hospital stays, and reduced recovery times than surgical patients. The US FDA approved the device in March 2005. Since then, the device has been used widely, although a 0.30% rate of complications related to infolding or partial compression of the device prompted a 'Dear Doctor' letter in January 2006. This article profiles the TAG device and evaluates endografting technology in general.

Thoracic aorta – dilated or not?

OBJECTIVES

Knowledge of normal aortic diameters is important in the assessment of aortic disease. The aim of this study was to determine normal thoracic aortic diameters.

DESIGN

77 patients undergoing computed tomography of the thorax were studied. The diameter of the thoracic aorta was measured at three levels in the ascending aorta and at three levels in the descending aorta. The diameter was studied in relation to age, sex, weight and height.

RESULTS

We found that aortic diameter is increasing with increasing age. Even sex and BMI influence the aortic diameter but to a lesser extent than age. The upper normal limit for ascending aorta can be calculated with the formula D(mm) = 31 + 0.16*age and for descending aorta with the formula D(mm) = 21 + 0.16*age. Thus a 20-year-old person has an upper normal limit for ascending aorta of 34 mm and an 80-year-old person has a limit of 44 m.

CONCLUSIONS

The thoracic aortic diameter varies with age, sex and body weight and height. The strongest correlation can be seen with age. Age should therefore be taken into consideration when determining whether the thoracic aorta is dilated or not.

Biophysical properties of the normal-sized aorta in patients with Marfan syndrome: evaluation with MR flow mapping

PURPOSE

To investigate the feasibility of magnetic resonance (MR) flow mapping in the assessment of aortic biophysical properties in patients with Marfan syndrome and to detect differences in biophysical properties in the normal-sized aorta distal to the aortic root between these patients and matched control subjects.

MATERIALS AND METHODS

Seventy-eight patients with Marfan syndrome with aortic root dilatation and 23 matched control subjects underwent MR flow mapping in four locations in the normal-sized aorta (1, ascending aorta; 2, thoracic descending aorta; 3, descending aorta at the level of the diaphragm; and 4, abdominal descending aorta). Distensibility at each location and flow wave velocity between locations were calculated.

RESULTS

Compared with the control subjects, patients with Marfan syndrome had decreased aortic distensibility at three of the four locations (levels 1, 2, and 4; P <.05) and increased flow wave velocity between all locations (P <.05) in the aorta. In patients with Marfan syndrome, flow wave velocity was also significantly increased along the entire aortic tract beyond the aortic root (from level 1 to level 4).

CONCLUSION

MR imaging reveals abnormal biophysical properties of the normal-sized aorta in patients with Marfan syndrome. Monitoring of these properties is relevant for evaluating disease progression and treatment options.

Surgical treatment for a ruptured thoracic aortic aneurysm

OBJECTIVE

The treatment for a ruptured thoracic aortic aneurysm remains controversial. This study was undertaken to assess the outcome from surgery.

METHODS

Between 1993 and 1998, we have performed 19 operations for a ruptured thoracic aortic aneurysm. Patients with an impending rupture or a chronic false aneurysm were excluded. There were 11 men and 8 women, with a mean age of 70.5 +/- 6.7 years. The aneurysm was caused by dissection in 8 patients. Of these, 7 were acute (Stanford type A, 6; type B, 1), and the other one was chronic (type B). Aortic rupture occurred into the pericardial cavity (n = 7), into the left lung (n = 6), the mediastinum (n = 3), the pleural cavity (n = 2), or into the esophagus (n = 1). Severely unstable hemodynamics were noted in 12 patients with a rupture into the pericardium, mediastinum, or pleural cavity (Group A). Inotropic support was required in each of these patients. Metabolic acidosis developed all but 1 patient. The 7 patients with a rupture into the lung or esophagus coughed or vomited blood (Group B). The operative approach was anterior (n = 17) or lateral (n = 2). Grafts were placed in the ascending aorta (n = 4), ascending and transverse arch aorta (n = 7), transverse arch aorta (n = 3), or in the descending thoracic aorta (n = 5). Selective cerebral perfusion was used in 13 patients.

RESULTS

There were 5 hospital deaths (26.3%). The postoperative complications included central nervous system dysfunction (n = 3), low cardiac output syndrome or cardiac arrhythmias (n = 3), respiratory failure (n = 4), acute renal failure (n = 1), and local or systemic infections (n = 4). The perioperative event-free rate was 36.8% overall, 25% in Group A, and 57.1% in Group B.

CONCLUSIONS

Patients with unstable hemodynamics require prompt operative intervention. Rupture into the esophagus is associated with a high mortality rate. Rupture in a thoracic aortic aneurysm can be successfully treated with emergency surgery.