My interest in Marfan syndrome started many years ago when I was in high school in South Africa. One of my classmates had Marfan. I heard him talk about it, and his words stuck in my mind throughout my medical school and surgical training in the 1970s and 1980s.
During my cardiovascular surgery fellowship at Baylor College of Medicine in the late ’80s, I encountered many patients with Marfan or Marfan-like conditions. We collected data on all of them — 151 patients — and tried to categorize each one by Ghent criteria. In the process, I noticed that a number of patients didn’t quite meet the Ghent criteria for Marfan, but clearly had some type of connective tissue condition. There were differences in how their aorta dissected and differences in family history. Some of these patients had aneurysms of the great vessels. Some had brain aneurysms. Women tended to have more mitral valve disease.
We called them “Marfanoid” patients. Today we know that some of these patients had Loeys-Dietz syndrome or inherited thoracic aneurysms with subtle criteria of Marfan. (These were subgroups not categorized at the time.)
In 1989, we published an article in Circulation about the surgical treatment of these patients. We noted that those who had aortic dissection needed multiple operations over time and their overall survival wasn’t as good as the general population. Life expectancy for patients with Marfan or Marfanoid conditions was only 32 years.
Composite valve grafts improve outcomes
It became clear that if we intervened earlier, the patient’s long-term prognosis was better.
At that time, we were replacing diseased aortic valves with composite valve grafts (a mechanical valve attached to a tube, replacing both the aortic valve and aortic root all in one). The results were pretty good. It looked like the rate of stroke over time in these patients was lower than in patients with only aortic valve replacement or aortic valve replacement plus a separate aortic root procedure. In addition, we learned that if we didn’t operate on the aortic root initially, many patients eventually would return with aortic root aneurysms.
We studied different ways of doing composite grafts, most notably the classic Bentall procedure. This technique involved replacing the aortic valve, aortic root, and ascending aorta, and reimplanting coronary arteries into the graft by the “inclusion” technique — in other words, without a separately mobilized, free coronary artery ostial button.
While the Bentall procedure had been performed for decades and modified over the years, we made noteworthy modifications in the early 1990s to better secure grafts.
During that time, we studied 348 patients with composite valve grafts and noticed their tendency to have heart attacks after their operation. We realized that part of the problem was kinking in the tube graft to the right coronary artery. As a result, we introduced modifications in how the tube graft was positioned to reduce tension and prevent kinking, thus reducing incidence of heart attacks. In particular, for patients needing reoperations or needing root replacement during acute aortic dissection, a tube graft to the left main coronary artery and attachment of the right coronary artery directly as a button worked best.
Re-implantation replaces remodeling for valve-sparing aortic root repair
In 2013, our team at Cleveland Clinic published a study of 178 patients that showed remodeling operations in patients with Marfan and Marfanoid conditions were failing at a higher rate than re-implantation procedures for valve-sparing aortic root repair. That’s when we stopped performing remodeling operations for Marfan.
Now re-implantation is the standard valve-sparing procedure for patients with connective tissue disorders and large aortic roots. Indeed, our experience with our modification of the re-implantation operation as of December 2019 exceeds 1,000 re-implantations, with a very low operative mortality risk. Our total experience of all cardiovascular operations on Marfan patients also exceeds 1,000 patients.
Over time we have refined the procedure to be even more successful, with specialized surgical techniques and modifications that have borne out excellent long-term results.
Our studies have shown that re-implantation has only a 5-7% risk of failure within 10 years. In other words, 93-95% of patients having re-implantation don’t need a repeat operation within 10 years — and probably better than 90% of patients within 20 years.
Long, healthy lives are possible
Today patients with Marfan can expect excellent results from these refined surgical techniques, as long as they have surgery before aortic dissection occurs.
Fortunately, deciding when to operate also has become easier thanks to an index we helped establish. By calculating the ratio of the patient’s height to the cross-sectional area of the aortic root, we can objectively determine when surgery is recommended. If the ratio is more than 10, indicating a larger aortic root and greater risk of dissection, we recommend surgery. That ratio is now part of the American College of Cardiology’s thoracic aortic disease guidelines.
For people with Marfan who have already had a reimplantation operation, the risk of later aortic dissection is very low. However, we strongly advise patients to continue taking medications to control their blood pressure and reduce their risk of aneurysms.
The cardiovascular care of people with Marfan has vastly improved over the last three decades. Patients today can enjoy a long, healthy life thanks to advanced surgical techniques that provide better outcomes.
Dr. Svensson will be presenting on aortic surgery for adults with Marfan, Loeys-Dietz, and other aortic conditions at the International E3 Summit on September 10, 2020, from 7:30-8:30 pm EST. It is free to register for this online event. For more information and to register, please go to Marfan.org/E3Register