Katrien François1, David Creytens2, Katya De Groote3, Joseph Panzer3, Kristof Vandekerckhove3, Daniel De Wolf3, Thierry Bové4. 1. Cardiac Centre, Department of Cardiac Surgery, University Hospital Ghent, Ghent, Belgium. Electronic address: katrien.francois@ugent.be. 2. Department of Pathology, University Hospital Ghent, Ghent, Belgium. 3. Cardiac Centre, Department of Pediatric Cardiology, University Hospital Ghent, Ghent, Belgium. 4. Cardiac Centre, Department of Cardiac Surgery, University Hospital Ghent, Ghent, Belgium.
Abstract
OBJECTIVE: Aortic root dilatation remains of concern late after repair for tetralogy of Fallot (ToF). We have previously demonstrated that the aortic root size decreases progressively after early correction. To test whether the aortic wall changes are intrinsic or acquired, a histologic study was performed of infants at early repair. METHODS: From 24 of 31 infants undergoing ToF repair (mean age, 5.9±4.9 months), ascending aortic biopsies were obtained. After conventional staining, the specimens were given a histologic score (0-3) for medionecrosis, ground substance accumulation, fibrosis, smooth muscle cell disarray, and apoptosis. The aortic root diameters were monitored using echocardiography for ≤2 years postoperatively. RESULTS: Nearly one half of the specimens showed signs of fibrosis (45%), with increased mucoid accumulation in 15% and elastin fragmentation in 5%. The aortic root was dilated in all infants at operation (mean indexed diameter-annulus, 38.1±5.8; sinus, 47.8±6; sinotubular junction, 38.7±5.4 mm/m2) and had regressed significantly within 2 years (mean indexed diameter-annulus, 27.9±4.7; sinus, 36.4±5.1; sinotubular junction, 30.4±6 mm/m2; P<.0001). The total histology score showed no correlation with indexed diameter regression at 2 years. CONCLUSIONS: Infants with ToF undergoing repair around 6 months old already had limited features of aortic wall degradation at surgery. Echocardiographic follow-up, however, demonstrated significant reductions in the indexed aortic diameters. We presume that early repair of ToF will prevent a disproportionate aortic diameter increase by halting progression of the limited histologic changes potentially predisposing to late aortic dilatation.
OBJECTIVE: Aortic root dilatation remains of concern late after repair for tetralogy of Fallot (ToF). We have previously demonstrated that the aortic root size decreases progressively after early correction. To test whether the aortic wall changes are intrinsic or acquired, a histologic study was performed of infants at early repair. METHODS: From 24 of 31 infants undergoing ToF repair (mean age, 5.9±4.9 months), ascending aortic biopsies were obtained. After conventional staining, the specimens were given a histologic score (0-3) for medionecrosis, ground substance accumulation, fibrosis, smooth muscle cell disarray, and apoptosis. The aortic root diameters were monitored using echocardiography for ≤2 years postoperatively. RESULTS: Nearly one half of the specimens showed signs of fibrosis (45%), with increased mucoid accumulation in 15% and elastin fragmentation in 5%. The aortic root was dilated in all infants at operation (mean indexed diameter-annulus, 38.1±5.8; sinus, 47.8±6; sinotubular junction, 38.7±5.4 mm/m2) and had regressed significantly within 2 years (mean indexed diameter-annulus, 27.9±4.7; sinus, 36.4±5.1; sinotubular junction, 30.4±6 mm/m2; P<.0001). The total histology score showed no correlation with indexed diameter regression at 2 years. CONCLUSIONS:Infants with ToF undergoing repair around 6 months old already had limited features of aortic wall degradation at surgery. Echocardiographic follow-up, however, demonstrated significant reductions in the indexed aortic diameters. We presume that early repair of ToF will prevent a disproportionate aortic diameter increase by halting progression of the limited histologic changes potentially predisposing to late aortic dilatation.
Authors: Michal Schäfer; Alex J Barker; James Jaggers; Gareth J Morgan; Matthew L Stone; Uyen Truong; Lorna P Browne; Ladonna Malone; D Dunbar Ivy; Max B Mitchell Journal: Eur J Cardiothorac Surg Date: 2020-03-01 Impact factor: 4.191