Catheter Management of Coarctation

Excerpt

Coarctation of the aorta is a type of congenital heart disease which is relatively common compared to the other congenital malformations with an approximate incidence of 3 cases out of 10,000 live births. This pathology is described as a narrowing or stenotic region in which blood traverses from ascending to descending aorta. Most commonly, it is present as a well defined stenotic region at the juxtaductal location. This defect is complex as it can present through the spectrum of age ranges, be associated with other congenital defects (patent ductus arteriosus, ventricular septal defect, bicuspid aortic valve, hypoplastic left heart syndrome), and carries a diffuse array of clinical case presentations. Coarctation of the aorta, first acknowledged by Morgagni in 1760, carries a poor clinical prognosis with a mean age of death at 34 years of age and a 75% mortality at a median age of 46, according to a well-documented autopsy study.

Surgical intervention for coarctation of the aorta was first described in 1944. It was performed via open lateral thoracotomy by resecting the stenotic segment of the aorta with re-anastomosis of the resected ends. This intervention was found to have been associated with a high incidence of re-coarctation. This led to the next intervention, which was called patch aortoplasty technique. This technique involved an incision across the stenotic region with a prosthetic patch sutured across the incision area. This led to a reduction in re-coarctation but was met with a high incidence of aneurysmal formation in approximately 20 to 40% of cases.

Another procedure was developed for the management of coarctation of the aorta. Subclavian flap aortoplasty involves incision of the left subclavian artery down to the aortic isthmus with anastomosis of this flap with the incision across the coarcted segment to increase the vessel lumen of the aortic segment. This procedure demonstrates a 23% recurrence rate with some incidence of aneurysmal formation and rarely is associated with a complication of left arm claudication with exercise.

The current preferred method of surgical management of coarctation of the aorta in the majority of surgical centers in the world is the extended end to end anastomosis given its relatively low re-coarctation rate between 4% to 13%. This intervention involves clamping of the aortic arch proximally at the take-off of the subclavian artery and distal to the coarct segment. A surgical incision is made in the inferior part of the aortic arch, the coarcted portion is resected, and the end-to-end anastomosis is completed at the arch and descending aorta. An interposition graft technique is utilized in adult-sized patients and in those with a long coarcted segment of the aorta. The aorta is clamped proximally and distally to the coarcted segment, which is resected. In the place of the resected segment, a tube graft that is composed of a Dacron or aortic homograph is secured by creating two surgical anastomoses.

Transcatheter based intervention utilizing balloon angioplasty of the coarcted segment was first utilized in 1982. Compared to the surgical techniques, however, there was a significantly high re-coarctation rate in infants and less pronounced rate in adolescents and adults in the long term. Further development of technology, such as covered stents, has improved outcomes. This review will address the transcatheter management of coarctation of the aorta.