This isn’t right. He very well could have a genetic mutation and that has nothing to do with those factors . I suggest you contact a geneticist in your area and ask for a test. It’s a genetic test that tells you if you have any of the gene mutations that cause dissections and aneurysms. It is very simple and it consists of spitting in a tube and you get results within 6 weeks. My son and I both have the ACTA2 gene. I had my dissection at age 27- I was in perfect health. I had perfect blood pressure, had never smoked, low cholesterol and ideal weight. I was a runner. My type 111 dissection included my ascending, descending, carotid , celiac, arch and femoral arteries. The surgeon told me it looked like a bomb went off on my chest. My son was 15 when he had exactly the same dissections. He was also in ideal health. Now that we are survivors we know it’s important to take care of ourselves with proper diet, mild exercise(no weights over 10lbs,walking, swimming are all ideal for us. But our issues were caused by genetic variances, not any lifestyle we were leading. It is a common misconception that aneurysm and dissections are caused only by smoking, obesity, high blood pressure and age. With genetic mutations it’s just dumb luck that leads us to open heart surgery.