Male-female differences in immunohistological and biomechanical properties of the thoracic
aorta

Thoracic aortic aneurysms (TAA) result from progressive dilatation of the
thoracic aorta and confer a risk for aortic dissection or rupture, which is
associated with significant morbidity and mortality. In the Netherlands there
are an estimated 200.000 adults with TAA, and annually 600 deaths after aortic
dissection or rupture. There are clear differences in the incidence of TAA
between men and women, with a higher incidence in men. Little is known on
possible differences in outcome between male and female patients with Thoracic
Aortic Aneurysm (TAA). Aortic disease is thought to affect men more frequently
than women, and aortic growth is different between men and women. Current data
suggest that women are at an increased risk of both dying from aortic
dissection and having aorta-related complications compared to men (1). The
mechanisms for these male-female difference in TAA outcome remain, however,
unclear. The timing of preventive surgery is now not different for men and
women, but gender-based cut-off values for maximal aortic diameter based on
differences in vessel wall composition might be needed.

The current project aims to implement male-female specific insights into aortic
root and ascending aorta characteristics into clinical practice, allowing
better identification of high risk Thoracic Aortic Aneurysm (TAA) patients and
better timing of intervention.

With this study we aim to obtain insight into male-female differences in the
immunohistological and biomechanical properties of the thoracic aortic wall. In
order to reveal possible mechanisms for male-female differences in TAA.

Prospective cross-sectional study using aortic tissue.

The burden and risks for the participating patient will be minimal. Patients
who are already scheduled for elective thoracic aortic surgery will be
included. After surgery samples will be collected from the excised part of the
thoracic aorta (residual tissue). Tissue will be taken both from the aneurysm
site and *unaffected* sites at the cutting edges. Also blood samples will be
collected from these patients (together with the pre-operation blood sampling
which is performed as part of the standard pre-operative procedure). Altogether
there will be no extra invasive actions or procedures other than those that are
part of the standard care procedures.
The collected data will be managed with uttermost care and pseudonimized. The
coding list will be kept separate from the extracted data. Only the principal
investigators and executive researchers will have access to the data. There
will be no direct benefit for the participating patients, however there might
be a major benefit for future thoracic aortic disease patients.