Dr. A.L. Duijnhouwer has defended his PhD thesis titled ‘Dilatation of the great arteries’ on 27th August 2021 at the Radboud University Medical Centre, Nijmegen.

To mark this monumental occasion, we briefly caught up with Anthonie about his research.

Could you please tell us what your thesis is about?

Anthonie explains: “This thesis ‘Dilatation of the great arteries’ answers the question why in certain patient groups the aortic or pulmonary vessel widens and in which this leads to severe complications.

In one of the articles it has been shown that patients with a two-leaflet, rather than three-leaflet, aortic valve and a history of aortic narrowing (coarctation) are not at higher risk.

Aortic complications in Turner syndrome are less common than thought. Dilatation is more prevalent and the aortic diameter divided by height was found to be a good predictor of complication risks.

Associated factors of pulmonary artery dilation are: weak tissue, high pressure and a changed flow profile. No pulmonary artery complications were observed at a diameter below 75mm and a pressure beneath 50mmHg. Abnormal dilatation in combination with increased pulmonary pressure was no predictor for shorter lifespan. An explanation could be that patients were only seen at a late stage of their disease.”

What was your most surprising finding?

“Pulmonary arteries can become gigantic, but seem not to be at risk for dissection, in absence of fragile tissue or high pulmonary pressures,” shares Toon.

What’s next for you?

Watch the defence of the PhD thesis here.

Toon: “Still little is known about the risk factors of aortic dissection in patients with Turner syndrome and more longitudinal research is needed to find significant markers for aortic dissection.”

Diagram B.V. congratulates dr. Toon Duijnhouwer on this incredible milestone and wishes him all the best in his future endeavours.

Dr. A.L. Duijnhouwer’s research was supervised by promotors Prof. dr. M.J. de Boer and Prof. dr. J. Roos-Hesselink and copromotors A. van Dijk and R. van Kimmenade.

Foto Toon Duijnhouwer
Dr. A.L. Duijnhouwer