In aortic stenosis, replacing the aortic valve can keep the descending aorta from becoming increasingly dilated—thereby sparing the vessel itself from replacement.
"Our data simply confirm an intuitive concept: When the aortic dilatation is a consequence of the hemodynamic derangement due to flow through a stenotic aortic valve and not of a pathology of the aortic wall, correction of the valvular stenosis is sufficient to interrupt aortic dilatation," said lead author Dr. Mario Gaudino from Catholic University in Rome, in an email to Reuters Health.
"In the past," he noted, "very few studies have tried to distinguish between the different types of aneurysms in terms of evolution and treatment."
This week, he and his colleagues report on the evolution of aortic dimensions after surgery in 93 patients with moderate post-stenotic ascending aorta dilation (50 to 59 mm) who underwent aortic valve replacement alone.
During 15 years of follow-up, there were 16 deaths, but in no case was death attributed to an aortic event, according to a report published in the Journal of the American College of Cardiology.
In fact, no patient had an acute aortic event (rupture, dissection, pseudoaneurysm) during follow-up, and there were no reoperations for thoracic aortic pathology.
Aortic dimension during the first ten years after surgery did not change appreciably. The mean aortic diameter grew by only 1 mm, and the mean ascending aorta expansion rate was 0.3 mm per year.
"We are aware of the fact that our data contradict the published guidelines for the treatment of diseases of the ascending aorta," the researchers write.
However, they add, "these guidelines do not make specific recommendations for the different subtypes of aortic dilations, although it seems likely that the physiopathology, natural history, and treatment can be different between degenerative or atherosclerotic and post-stenotic aneurysms."
The investigators suggest, "Ascending aorta replacement should be considered only for very young patients with extremely long life expectancy."
In his email, Dr. Gaudino added, "We hope that our study can demonstrate that the actual approach to ascending aorta aneurism is too simplistic and underline the need of specific therapeutic guidelines for the different types of aortic aneurysms."
In an editorial, Dr. David D. Glower from Duke University Medical Center, Durham, North Carolina writes, "Current American College of Cardiology/American Heart Association guidelines recommend replacing the ascending aorta at the time of aortic valve replacement if the ascending aorta is more than 5.0 cm in any patient or if the ascending aorta is more than 4.5 cm in bicuspid patients. "
"Evidence supports the contention of Gaudino et al. that size alone is not enough to indicate replacement of the ascending aorta in many patients with aortas of less than 6.0 cm in diameter," Dr. Glower notes. "Guidelines are just guidelines. Guidelines need to be applied to individual patients by knowledgeable physicians."
J Am Coll Cardiol 2011;58:581-584,585-586. Abstract
Will Boggs MD • Reuters Health Information © 2011