Cardiovascular Report - Aortic Reconstruction in Connective Tissue Disorders
Aortic Reconstruction in Connective Tissue Disorders
Date: June 13, 2014
Branched surgical graft offers patients new hope.
What some people might say resembles a miniaturized, inflated dancing tube man at an auto dealership is really a branched surgical graft for replacing the entire thoracoabdominal aorta in patients with aortic aneurysm. Other than its obvious proximal and distal ends for aortic anastomoses, this device has four flexible arms for connecting to the renal arteries, superior mesenteric artery and celiac axis. James Black, chief of vascular surgery and endovascular therapy at The Johns Hopkins Hospital, and his colleagues introduced the branched surgical graft operation at Johns Hopkins mainly for patients with a connective tissue disorder like Marfan syndrome or Loeys-Dietz syndrome. In these patients, the whole of the thoracoabdominal aorta is at risk for developing life-threatening aneurysms. John Hopkins surgeons have now performed over 40 of these operations since 2007 on patients with genetically based aneurysms, with impressive results.
Aortic aneurysm is a hallmark of genetically caused connective tissue disorders. Marfan syndrome is related to mutations in FBN1, a gene encoding for the fibrillin-1 protein involved in elastic tissue integrity. Loeys-Dietz syndrome is caused by mutations in TGFBR1, TGFBR2 or SMAD3, which code for proteins involved in the control of cell signaling for blood vessel formation. Loeys-Dietz syndrome, first described by Johns Hopkins cardiologist Hal Dietz and colleague Bart Loeys in 2005, is more aggressive than Marfan syndrome.
“Our patients with connective tissue disorders are prime candidates for the branched surgical graft,” says Black. “Carrel patches or inclusion patches have been used traditionally for aortic branch reconstruction, but they leave the tissue at risk for recurrent aneurysm. This branched surgical graft eliminates the worry of new islands of aortic tissue becoming weak. Whenever possible, in any patient, we like to avoid more than one aortic operation.”
The branched surgical graft is placed in a daylong operation that requires a highly coordinated and practiced team of surgeons, nurses, perfusionists and anesthesiologists moving progressively from the proximal extent of the aorta distally, all the time protecting the spinal cord, kidneys and tissues supplied by the superior mesenteric and celiac arteries from ischemia. Eventually, the branches of the graft are trimmed to an optimal length and anastomosed beginning with a renal vessel.
Black describes the operation as an “emerging standard for repair” in patients with a connective tissue disorder. Last year at a meeting of the Eastern Vascular Society, he reported outcomes in patients followed for three to 47 months. None experienced additional aneurysmal degeneration, spinal cord injury or mesenteric complications, and none needed dialysis.