Objectives: Aneurysm formation after patch angioplasty for aortic coarctation is a frequent and potentially lethal complication, necessitating surgical reintervention. Although several mechanisms have been postulated, flow disturbance in a concomitant hypoplastic transverse aortic arch most likely contributes to the aneurysm formation. The outcome of the grafts after redo surgery, however, is unknown. The purpose of this study was to evaluate the outcome of the inserted graft in patients with surgery for aneurysm formation following patch angioplasty for coarctation of the aorta.
Methods: In 16 patients redo surgery was performed for aneurysm formation (diameter: 47.1+/-11.9 cm) (mean+/-SD), 12.7+/-2.1 years after the initial patch angioplasty. All patients had a concomitant arch hypoplasia. They were treated by insertion of a Dacron Gelseal graft (16-30 mm), but the associated hypoplastic arch segment was left untouched. To evaluate the evolution of the new graft, patients were followed by means of magnetic resonance (MR) imaging.
Results: The immediate postoperative outcome was uneventful in 12 patients. Four patients, however, suffered from a recurrent nerve paralysis and one of them of a spinal cord transection. The mean follow-up time was 54.1+/-17.9 months during which 59 magnetic resonance studies were performed. The number of MR studies per patient ranged from two to seven. The graft diameter increased significantly with 56+/-18%, range 20-82 (P<0.0001). This widening was most pronounced within the first year after surgery (43+/-16%, range 5-67) (P<0.0001).
Conclusions: Flow acceleration caused by an even mild hypoplastic transverse arch can put excessive strain on the distal part of the aortic arch. This can lead not only to aneurysm formation after patch angioplasty but also to excessive dilation of the Dacron Gelseal graft. At intermediate long-term follow-up, however, a stabilization of the graft dilation is observed.