Aortic root dilatation after repair of tetralogy of Fallot: pathology from the past?

Aortic dilation in adults with repaired tetralogy of Fallot: a single-centre study

BACKGROUND

Tetralogy of Fallot is the most prevalent cyanotic CHD. With the advent of advanced surgical methods, the majority of tetralogy of Fallot patients reach adulthood. However, many need re-intervention for the residual anomalies including residual right ventricular outflow obstruction, pulmonary regurgitation, residual ventricular septal defects, and progressive aortic dilatation. Aortic dilation could lead to aortic regurgitation or dissection requiring surgical correction. In the current study, we aimed to determine the prevalence and outcomes of aortic root dilatation in adults with repaired tetralogy of Fallot in our tertiary care centre.

METHODS

In this retrospective study, 730 consecutive patients with history of repaired tetralogy of Fallot were included. Aortic diameter at the level of annulus, the sinus of Valsalva, sinotubular junction, and the ascending aorta as measured by echocardiography were evaluated. Prevalence of outcomes necessitating re-intervention including aortic regurgitation and dissection were recorded.

RESULTS

The mean size of annulus, sinus of Valsalva, sinotubular-junction, and ascending aorta in the latest available echocardiography of patients were 2.4+/-0.4 cm, 3.3+/-0.5 cm, 2.9+/-0.5cm, and 3.2+/-0.5cm, respectively. Prevalence of dilatation of sinus of Valsalva, dilation of Ascending aorta, sinotubular-junction, and aortic annulus was 28.7%, 21%, 8.3%, and 1 %, respectively. Five patients had severe aortic regurgitation (0.6%) and underwent surgical repair. One of these patients presented with acute aortic dissection.

CONCLUSION

Aortic dilation is common in tetralogy of Fallot but prevalence of redo surgery for aortic dilation, regurgitation, and adverse events including acute dissection is low.

Characteristics of the aortic root morphology in conotruncal anomaly of the congenital heart disease

BACKGROUND

Aortopathy is a well-known feature of conotruncal anomalies, but it remains unknown whether valve-sparing aortic root replacement, such as the David procedure, is feasible in young patients with severe aortic regurgitation. We assessed the aortic valve complex and aortic root morphology in patients with conotruncal anomalies using echocardiography. Furthermore, we evaluated the relevant factors associated with aortopathy in this population.

METHODS

A total of 172 adult patients with conotruncal anomalies were enrolled in this study. Dimensions of the aortic valve complex were measured at the level of the sinus of Valsalva (SV) and sinotubular junction (STJ). The geometric height (GH), effective height (EH), and coaptation length (CL) were also assessed to analyze the aortic valve complex in detail.

RESULTS

Sixteen of 172 patients were excluded due to poor imaging; 105 patients with tetralogy of Fallot, 24 with double outlet right ventricle, and 27 with transposition of the great arteries totaling 156 patients (32+/-11 years old) were included in the analysis. The patients were divided into four groups: Group 1 (98 patients) had no dilatation of SV or STJ; Group 2 (32 patients) had dilated SV and STJ; Group 3 (14 patients) had dilated SV; and Group 4 (12 patients) had dilated STJ. GH and EH in Group 2 were also highest among the four, whereas CL was not significantly shortened. Multivariate analysis revealed that male sex, age, and conduit repair were risk factors for aortopathy in this population.

CONCLUSIONS

Patients with dilated SV and STJ (Group 2) were the most common among the patients with aortopathy (Groups 2, 3, and 4). The aortic valve leaflets themselves were enlarged, and the poor coaptation of the valve tips was compensated in spite of aortic root dilatation, which plays an important role in preventing severe aortic regurgitation in this population. Overall, valve-sparing aortic valve replacement is more feasible in the young populations than we expected.

Histologic Abnormalities of the Ascending Aorta: Effects on Aortic Remodeling after Intracardiac Repair of Tetralogy of Fallot

We evaluated aortic tissue specimens from patients undergoing tetralogy of Fallot repair, to determine whether histologic abnormalities affect postsurgical aortic remodeling and other patient-related variables. Using light microscopy, we studied full-thickness aortic wall tissue operatively excised from 118 consecutive patients undergoing intracardiac repair of tetralogy of Fallot. We performed multiple linear regression analysis to identify independent predictors of change in aortic root dimensions, which we measured with echocardiography after repair and every 3 months thereafter. Thirty histologically normal specimens were used as controls. Elastic fiber fragmentation was found in 74.6% of the abnormal specimens, mucoid extracellular matrix accumulation in 49.2%, smooth muscle cell nuclei loss in 39%, smooth muscle cell disorganization in 28.8%, and medial fibrosis in 52.5%. At a mean follow-up time of 83.55 ± 42.08 months, mean aortic sinotubular diameter decreased from 28.79 ± 9.15 to 27.16 ± 8.52 mm/m2 (r =-0.43; P <0.001). Aortic sinotubular diameter decreased by 0.6 mm/m2 among females (β =0.6, SE=0.31; P =0.05) and by 0.88 mm/m2 in patients who had elastic fiber fragmentation or loss (β =0.88, SE=0.38; P =0.02). In bivariate and multiple linear regression analysis, duration of follow-up emerged as an independent predictor of aortic remodeling. The aortic histopathologic changes in our patients had an independent negative impact on the degree of aortic remodeling after surgery. We observed the most improved aortic sinotubular diameter in patients who had either histologically normal aortas or aortas with elastic fragmentation.

Aortic dilatation after tetralogy of Fallot repair: A ghost from the past or a problem in the future?

INTRODUCTION AND AIMS

Intrinsic aortopathy can lead to dilatation late after tetralogy of Fallot (TOF) repair. Its extent and prevalence are not known. We aimed to assess aortic dimensions and elasticity and to find predictors of aortic dilatation.

METHODS

A total of 126 adults were prospectively included after TOF repair and compared to 63 gender- and age-matched controls. Transthoracic echocardiography was used to assess aortic diameters at the level of the sinuses of Valsalva and ascending aorta and aortic dilatation was defined as z-score >+2. M-mode parameters of the ascending aorta were used to calculate strain, distensibility and stiffness index.

RESULTS

TOF patients (mean age 30±9 years; 52% male) had a complete repair at a median age of five (2-49) years; mean follow-up time since repair was 23±7 years. The prevalence of aortic dilatation at the sinuses of Valsalva and ascending aorta was 29% and 24%, respectively. Compared to controls, TOF patients had a higher ascending aorta z-score, lower strain (6.4% [0.0-61.5] vs. 15.2% [0.0-45.0], p<0.01) and higher stiffness index (7.3 [0.8-23.6] vs. 3.1 [0.9-14.1], p<0.01). On multivariate analysis male gender was strongly associated with sinuses of Valsalva dilatation (odds ratio 6.3, 95% confidence interval 1.5-26.3, p=0.01).

CONCLUSIONS

The prevalence of aortic dilatation late after TOF repair is significant, with a larger and stiffer ascending aorta. Male gender appears to influence aortic root dilatation. This aortopathy requires careful follow-up in order to prevent future complications.

A Comparative Study of Histopathological Changes in the Ascending Aorta and the Risk Factors Related to Histopathological Conditions and Aortic Dilatation in Patients With Tetralogy of Fallot and a Functionally Univentricular Heart

BACKGROUND

The purposes of this study were to prospectively evaluate the histologic characteristics of the aortic wall of patients undergoing univentricular type of repair and compare the same with the findings observed in patients undergoing intracardiac repair of tetralogy of Fallot (TOF).

PATIENTS AND METHODS

Operatively excised full-thickness aortic wall tissue from 99 consecutive patients undergoing either intracardiac repair of TOF (group I; n=42) or univentricular repair (group II; n=57) were studied by light microscopy. Age at operation was 13 months to 28 years (mean 99.97±73.21months) for group I and 9 months to 25 years (mean 79.52±60.09) months for group II patients.

RESULTS

Dilatation of the ascending aorta was present in 85.7% patients with TOF and 91.2% patients with a univentricular heart. Seventeen (17.2%) aortic specimens were histologically normal and were used as normal controls (group I, n=5; group II, n=12). A lamellar count of less than 60 was associated with a sensitivity of 97.2% and a specificity of 66.7% in patients undergoing repair of TOF and a sensitivity of 84.6% and a specificity of 80% in patients undergoing univentricular type of repairs respectively. Patients undergoing intracardiac repair of TOF and those undergoing univentricular repair exhibited 23.67 times (15.91-147.40) and 8.48 times (3.62-15.84) increased risk of aortic dilatation respectively.

CONCLUSIONS

Our findings indicate the existence of significant elastic fragmentation, muscle disarray, medionecrosis and fibrosis involving the ascending aortic media in patients with a functionally univentricular heart and dilated aorta. These histopathological changes are similar to those encountered in patients with TOF and dilated aorta.

Noninvasive Assessment of Vascular Function in Postoperative Cardiovascular Disease (Coarctation of the Aorta, Tetralogy of Fallot, and Transposition of the Great Arteries)

Using noninvasive techniques, we sought to assess arterial stiffness, impedance, hydraulic power, and efficiency in children with postoperative tetralogy of Fallot (TOF), coarctation of the aorta (COA), and transposition of the great arteries (TGAs). Results were compared with those of healthy peers. Fifty-five children with repaired congenital heart disease (24 TOFs, 20 COAs, and 11 TGAs) were compared with 55 age-matched control subjects (CTRL). Echocardiographic Doppler imaging and carotid artery applanation tonometry were preformed to measure aortic flow, dimensions, and calculate pulse wave velocity, vascular impedance and arterial stiffness indexes, hydraulic power (mean and total), and hydraulic efficiency (HE) which were calculated using standard fluid dynamics equations. All congenital heart disease subgroups had higher pulse wave velocity than CTRL. Only the COA group had higher characteristic impedance. Mean power was higher in TGA than in CTRL and TOF, and total power was higher in TGA than in CTRL and TOF. Hydraulic efficiency was higher in TOF than in COA and TGA. In conclusion, children with TOF, COA, and TGA have stiffer aortas than CTRL. These changes may be related to intrinsic aortic abnormalities, altered integrity of the aorta due to surgical repair, and/or acquired postsurgery. These patients may be at increased long-term cardiovascular risk, and long-term follow-up is important for monitoring and assessment of efforts to reduce risk.

Histopathologic changes in ascending aorta and risk factors related to histopathologic conditions and aortic dilatation in patients with tetralogy of Fallot

OBJECTIVE

The purposes of this study were to evaluate the histologic characteristics of the aortic wall and the risk factors related to histopathology and aortic dilatation in patients undergoing intracardiac repair of tetralogy of Fallot.

METHODS

Operatively excised full-thickness aortic wall tissue from 98 consecutive patients undergoing intracardiac repair of tetralogy of Fallot aged 6 months to 47 years (mean 104.5 +/- 102.8 months; median 72 months) were studied by light microscopy. The receiver operating characteristic curve analysis was done to quantify the diagnostic accuracy of loss of lamellar counts and multiple logistic regression models.

RESULTS

Twenty-five (25.5%) aortic tissue specimens were indicated as histologically normal and were used as normal controls. The incidence of elastic fragmentation, increased ground substance, medionecrosis, smooth muscle disarray, and fibrosis was 74.5%, 54%, 39.8%, 26.5%, and 57.1%, respectively. A lamellar count of less than 60 was associated with a sensitivity of 80% and a specificity of 87.67%. Area under the receiver operating characteristic curve indicated that 93.37% (standard error +/- 0.039) of the time the value of lamellar count was lower for the abnormal histopathology group than for the normal group (P < .001). The risk of aortic dilatation was 15.97 times higher in patients with histopathologically abnormal aorta.

CONCLUSIONS

The majority of aortic media of the ascending aorta in cyanotic tetralogy of Fallot indicates significant loss of lamellar units and pre-existing intrinsic aortopathy. The changes are present since infancy and are more pronounced in older patients subjected to long-standing cyanosis and volume overload and may account for or may coexist with the higher incidence of aortic dilatation encountered in these patients.

Giant Aortic Aneurysm 18 Years After Repair of Double-Outlet Right Ventricle With Pulmonary Stenosis

Substantial long-term morbidity after a successful operation in complex congenital heart defects is a matter of concern. We present a patient with a giant ascending aortic aneurysm 18 years after repair of a double-outlet right ventricle with pulmonary stenosis. Our report emphasizes the need for ongoing follow-up into adulthood.

Intrinsic histological abnormalities of aortic root and ascending aorta in tetralogy of Fallot: evidence of causative mechanism for aortic dilatation and aortopathy

BACKGROUND

Dilatation of the aortic root is a known feature in tetralogy of Fallot (TOF) patients with pulmonary stenosis (PS) or pulmonary atresia (PA). We hypothesized that intrinsic histological abnormalities of the aortic wall present since infancy are an important causative factor leading to aortic root dilatation.

METHODS AND RESULTS

We examined the aortic histology of 17 cases with TOF and PS/PA from our cardiac morphology archive and compared them with a control group of normal aortas. Measured circumference of the aortic root at the sinotubular junction and at the ascending aorta was indexed to the left ventricle. Aortic walls were studied by light microscopy with the use of various stains. Seventeen TOF cases (7 with PS, 10 with PA) including 7 infants, 2 children, and 8 adults were compared with 11 hearts with normal aorta. Aortic root circumference to left ventricular index and ascending aortic circumference to left ventricular index were 1.24+/-0.25 and 1.37+/-0.24, respectively, in the TOF group versus 0.89+/-0.10 and 0.88+/-0.11, respectively, in the control group (P<0.001). Histological changes of grade 2 or 3 were present in 29% (medionecrosis), 82% (fibrosis), 35% (cystic medial necrosis), and 59% (elastic fragmentation) in the ascending aorta of the TOF group. Histology grading scores were significantly higher in the TOF group (median score, 7; range, 1 to 12) compared with normal controls (median score, 2; range, 0 to 6) and correlated with the ascending aortic circumference to left ventricular index (r=0.525, P=0.03).

CONCLUSIONS

There are marked histological abnormalities in the aortic root and ascending aortic wall of patients with TOF present from infancy, suggesting a causative mechanism for subsequent aortic root dilatation.