Aortic aneurysm after patch aortoplasty for coarctation: Analysis of patch size and wall growth

Aortic aneurysm may develop after surgery for coarctation of aorta especially patch aortoplasty. The size of patch and of adjacent native aortic wall was analyzed to determine whether aortic dilatation represents a true aneurysm. Electron beam tomography (EBT) was done on 19 patients, three months to 17.5 years after patch aortoplasty. Tomograms of aorta were obtained in 6-mm slices, and maximal cross-sectional area was digitized to obtain: total circumference (Ct), patch component (Cp), and aortic wall component (Cw). Ct, Cp, and Cw were normalized to the circumference of distal aorta (Cda) as: isthmus/distal aorta (Ct/Cda), patch segment/distal aorta (Cp/Cda), wall segment/distal aorta (Cw/Cda). Ct/Cda ranged from 109% to 260%. In 12 patients (group A), it varied from 168% to 260%; and in seven (group B), 109% to 133%. There was strong correlation (r = 0.92) between Ct/Cda and Cp/Cda. Ct/ Cda, Cp/Cda, and Cp/Cw were higher in group A than B (p < 0.001) but Cw/Cda did not differ. Cw/ Cda was greater than the coarctation/distal aorta diameter ratios of preoperative angiograms, consistent with accelerated aortic wall growth postsurgery. No definite aneurysm was seen. Localized dilatation of aorta following patch aortoplasty in children is primarily due to a large synthetic patch and, partly, to increased aortic wall growth. Serial EBT or magnetic resonance imaging is indicated to monitor aortic wall growth and occurrence of aneurysm. Aortic aneurysm may develop after surgical repair of coarctation of aorta. Its occurrence is high after synthetic patch aortoplasty, and the reported incidence following surgery in the pediatric age group has varied widely from 0% to 5% [3, 7] and 24% to 51% [4, 5, 14, 15]. The experience in adult patients has been comparable, with the incidence influenced by longer observation periods [1, 2, 11]. The diagnosis is usually based on localized dilatation of the aorta at the repair site. To our knowledge, the contribution of the patch itself to the aortic enlargement has not been investigated. Whether the patch alone accounts for the dilatation or whether the aortic wall is truly aneurysmal is an important, as yet unanswered, question. The purpose of our study was to determine: (1) size of aorta at repair site; (2) size of patch and of adjoining aortic wall; and (3) aortic wall distortions or outpouchings.