For patients with Marfan or Loeys-Dietz syndrome who are at risk of rupture of the aorta, the standard of care has been surgery to replace both the root and the valve of the aorta with a mechanical or biological prosthesis. While the root replacement holds up over time, prosthetic valves have substantial implications for the growing child.
“If you’re 55 and you have an aneurysm, and your valve is not perfect, you can get a bioprosthesis and chances are it will be OK until you’re 75,” says pediatric cardiac surgeon Luca Vricella. “But if you’re 15, that valve will become bad within the next 10 years, and you’ll have to have another surgery.”
With the mechanical valve option, adds Vricella, patients have to be on life-long blood thinners, which increases their risk of stroke or bleeding. To get around these risks, Vricella offers young patients a valve-sparing approach, in which he replaces the aortic root and then reimplants the patient’s existing valve, reducing the need for valve replacement down the road and long-term anticoagulation therapy.
In valve sparing aortic root replacement, Vricella excises the aorta at the sinotubular junction, dissects down the aorta to the aortic valve and removes the aneurysmal aortic wall; he then re-suspends the native valve within the tube graft and reattaches the coronary arteries.
The results? Ten-year survival of 88 percent with only a 6.2 percent re-operation rate, versus a 42 percent re-operation rate with the remodeling approach (Semin Thorac Cardiovasc Surg Pediatr Card Surg Ann 2017 (in press)).
“We believe the reimplantation technique is simpler than other techniques, provides better hemostasis, and stabilizes the root better,” says Vricella.
The Johns Hopkins Children’s Center is well-positioned to treat these young patients at risk of aortic rupture, concludes Vricella, pointing to resources like the Broccoli Center for Aortic Diseases, the Johns Hopkins Comprehensive Marfan Center, and renowned faculty physicians, like geneticist Hal Dietz, who first identified the genes for Marfan and Loeys-Dietz syndromes. Also, Johns Hopkins pediatric cardiac surgeons like Vricella have deep experience in treating infants with congenital heart conditions like tetralogy of Fallot and transposition of the great arteries. These patients are now an emerging group of young adults needing aneurysm surgery.
“If you had surgery for transposition as a baby and now you’re a 22-year-old with an aortic root aneurysm with aortic valve regurgitation, you need someone who understands congenital heart disease, not an adult surgeon who just performs aortic surgery in a normally connected heart,” says Vricella. “We have a particular expertise and experience with young people who have aneurysms, which is why we’re considered the No. 1 center in the world for this particular pathology.”