Delayed Diagnosis of Pulmonary Artery Thrombosis in a Patient Undergoing Mitral Valve Replacement.

ABSTRACT: The occurrence of pulmonary artery thrombus in association with rheumatic mitral stenosis is a rare complication. Pulmonary artery thrombus formation may worsen pulmonary artery pressures, and this may precipitate acute right heart failure. The possible mechanisms behind pulmonary artery thrombus formation during mitral valve replacement surgery could be acute coagulopathy following surgery, the presence of chronic pulmonary thromboembolism, or chronic atrial fibrillation. We report an unusual case of pulmonary artery thrombus in a patient with rheumatic MS which was diagnosed with transoesophageal echocardiography after MVR.

Is menstruation a valid reason to postpone cardiac surgery?

Background: Cancellation of any scheduled surgery is a significant drain on health resources and potentially stressful for patients. It is frequent in menstruating women who are scheduled to undergo open heart surgery (OHS), based on the widespread belief that it increases surgical and menstrual blood loss. Aims: The aim of this study was to evaluate blood loss in women undergoing OHS during menstruation. Settings and Design: A prospective, matched case-control study which included sixty women of reproductive age group undergoing OHS. Patients and Methods: The surgical blood loss was compared between women who were menstruating (group-M; n = 25) and their matched controls, i.e., women who were not menstruating (group-NM; n = 25) at the time of OHS. Of the women in group M, the menstrual blood loss during preoperative (subgroup-P) and perioperative period (subgroup-PO) was compared to determine the effect of OHS on menstrual blood loss. Results: The surgical blood loss was comparable among women in both groups irrespective of ongoing menstruation (gr-M = 245.6 ± 120.1 ml vs gr-NM = 243.6 ± 129.9 ml, P value = 0.83). The menstrual blood loss was comparable between preoperative and perioperative period in terms of total menstrual blood loss (gr-P = 36.8 ± 4.8 ml vs gr-PO = 37.7 ± 5.0 ml, P value = 0.08) and duration of menstruation (gr-P = 4.2 ± 0.6 days vs gr-PO = 4.4 ± 0.6 days, P value = 0.10). Conclusion: Neither the surgical blood loss nor the menstrual blood loss is increased in women undergoing OHS during menstruation.

Bivalirudin anticoagulation in neonates and infants undergoing cardiac surgery.

OBJECTIVES: To determine the dosage of bivalirudin as the anticoagulant for cardiac surgery in neonates and infants. DESIGN: Pilot study. SETTING: Tertiary-care hospital. PARTICIPANTS: Twenty-five neonates and infants with congenital heart disease (CHD) undergoing cardiac surgery. INTERVENTIONS: The children received a 1 mg/kg bivalirudin bolus followed by a 2.5 mg/kg/h infusion as the anticoagulant for cardiac surgery. The dose was adjusted subsequently to maintain an activated clotting time (ACT) >480 s. MEASUREMENTS AND MAIN RESULTS: The mean age and weight were 5.3 months and 5.2 kg, respectively. Out of the 25 children, 16 were cyanotic. Baseline rotational thromboelastometry (ROTEM) (Tem Innovations GmbH, Munich, Germany) analysis revealed an underlying coagulation defect across EXTEM, INTEM, FIBTEM, and ADPTEM parameters. The dose of anticoagulant required was 1 mg/kg, followed by a 2.2 ± 0.4 mg/kg/h infusion. Only 1 child required an additional bolus dose. The ACT remained elevated for 4 hours after discontinuation of infusion. The mean 24-h postoperative chest tube drainage was 92 ± 36 mL. Excessive bleeding occurred in 4 children, 1 of whom required re-exploration. The platelet count remained low for 5 days, and, postoperatively, the prothrombin time and activated partial thromboplastin time remained low for 2 days. CONCLUSIONS: Effective anticoagulation was achieved with bivalirudin in the neonates and infants undergoing cardiac surgery. The dose required to maintain an ACT >480 s was 1.0 mg/kg, followed by 2.2 ± 0.4 mg/kg/h. The ACT remained elevated for 4 h after the discontinuation of bivalirudin infusion, resulting in an increased chest-tube output in some patients. Randomized, controlled trials are needed to further evaluate the safety of bivalirudin in the neonates and infants with complex congenital heart disease undergoing cardiac surgery with cardiopulmonary bypass.

Effect of change in tidal volume on left to right shunt across ventricular septal defect in children - A pilot study.

BACKGROUND: Pulmonary vascular resistance, an important determinant of shunting across ventricular septal defects (VSD), rises at both extremes of lung volume. AIMS: We sought to determine the effect of changes in tidal volumes (VT) on pulmonary blood flow (Qp), systemic blood flow (Qs), and shunt (Qp/Qs) in children with VSD. SETTING: Single-center teaching hospital. DESIGN: Prospective observational study. METHODS: Thirty children with a mean age of 11.8 ± 5 months undergoing surgical closure of VSD were studied. Hemodynamics and shunt-related parameters were assessed using transthoracic echocardiography measured at three different VT i.e. 10, 8, and 6-ml/kg keeping the minute ventilation constant. RESULTS: Reduction in VT from 10 to 8 to 6 ml/kg led to a reduction in gradient across VSD measuring 23.5, 20 and 13 mmHg respectively (P < 0.001). Similarly, right ventricluar outflow tract (RVOT) diameter, RVOT velocity time integral, Qp (57.3 ± 18.1, 50.6 ± 16.9, 39.9 ± 14.7 mL; P < 0.001), Qs (24.1 ± 10.4, 20.0 ± 8.7, 15.3 ± 6.9 mL; P < 0.001) and peak airway pressure (17.2 ± 1.5, 15.8 ± 1.3, 14.5 ± 1.2 cmHg; P < 0.001) showed progressive decline with decreasing VT from 10 to 8 to 6 ml/kg, respectively. However, Qp/Qs (2.4 ± 0.4, 2.6 ± 0.4, 2.6 ± 0.4) demonstrated a minor increasing trend. CONCLUSION: Lower VT reduces the gradient across VSD, the pulmonary blood flow, and the peak airway pressure. Hence, ventilation with lower VT and higher respiratory rate maintaining adequate minute ventilation might be preferable in children with VSD. Further studies are required to confirm the findings of this pilot study.

Bilateral whole lung lavage by lung isolation in a child with pulmonary alveolar proteinosis: A new technique.

We present two rare cases of children who presented with progressive exertional breathlessness and dry cough. They also had history of bluish discoloration of mucous membranes, hands and feet on exertion. Both were diagnosed to have pulmonary alveolar proteinosis after a high-resolution computed tomography and bronchoalveolar lavage. They were subjected to bilateral whole lung lavage (WLL) as a salvage therapy. Bilateral WLL was performed in a single sitting with the help of a modified endotracheal tube. The anesthetic technique included a modified cuffed endotracheal tube for accomplishing WLL. After the procedure, both children improved clinically and functionally.

Left Bidirectional Cavopulmonary Connection in Raghib's Defect: Report of 5 Cases and Review of Literature.

We report five male patients aged 3, 6, 8, 10, and 15 years, respectively, undergoing left bidirectional cavopulmonary connection and concomitant Dacron patch closure of the atrial septal defect for Raghib's defect with persistent left superior vena cava. The circulation was successfully corrected. This extracardiac procedure uses only autogenous tissues having growth potential, reduces myocardial ischemia, and avoids later baffle deterioration with pulmonary venous obstruction associated with intra-atrial baffling procedures. A wider appreciation and application of this management modality is warranted.

Long-Term Outcomes of the Double-Barrel Technique for Superior Sinus Venosus Defect With Partially Anomalous Pulmonary Venous Connection.

BACKGROUND: Repair of superior sinus venosus defect with high partially anomalous pulmonary venous connection (PAPVC) using an intracardiac baffle may be complicated by systemic or pulmonary venous pathway obstruction and sinus nodal dysfunction (SND). Our surgical strategy for repair of all types of superior sinus venosus defect has evolved chiefly to avoid the abovementioned complications and preserving the growth potential of the superior cavoatrial junction. METHODS: Between 2007 and 2019, fifty consecutive patients aged 2 to 60 (mean, 17.6±16.7) years underwent repair of superior sinus venosus defect using the double-barrel technique as described. The anomalous pulmonary veins drained into the superior cavoatrial junction in 17 patients and more than 2 cm above the cavoatrial junction in 33 patients. RESULTS: There were no early or late deaths and no reoperations. At a mean follow-up of 103.9 (±50.2) months, all survived the operation, and actuarial freedom from SND was 97.9% (±standard error, 0.02%; 95% CI: 0.86-0.99). No patient had systemic or pulmonary venous pathway obstruction. A permanent pacemaker was required in one (2%) patient for sick sinus syndrome. CONCLUSIONS: The double-barrel method is an expedient, safe, and effective technique in superior sinus venosus defect. It provides dual drainage of superior vena cava preserving the superior cavoatrial junction without causing systemic or pulmonary venous pathway obstruction and can be utilized in all cases including those with high PAPVC. Preservation of the cavoatrial junction and use of autogenous atrial tissue for systemic venous pathway avoids SND and preserves growth potential.

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 (ß =0.6, SE=0.31; P =0.05) and by 0.88 mm/m2 in patients who had elastic fiber fragmentation or loss (ß =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.

Early evaluation of the aortic root after Nicks' procedure.

OBJECTIVES: To determine the influence of surgical techniques adopted to avoid suture line disruption, periprosthetic leakage, patch dislodgement, pericardial patch aneurysm formation, and the long-term stability of aortic root enlargement (ARE) during aortic valve replacement (AVR). METHODS: One hundred fifteen patients undergoing AVR or combined aortic and mitral valve replacements with Nicks' posterior ARE between 1997 and 2019 underwent long-term echocardiographic and angio-computed tomographic evaluation. Age was 11-72 years (AVR: median, 30; interquartile range, 21-47 years; AVR and mitral valve replacement: median, 27.5; interquartile range, 20-37.5 years). The aortotomy was closed using autologous pericardial patch and Teflon-buttressed sutures. RESULTS: Hospital mortality was 1.7% (n = 2), with 4 (3.5%) late deaths. At a mean follow-up of 123.11 ± 77.67 months, the survival probability from Kaplan-Meier was 93.25 ± 0.03%. No cases of severe prosthesis-patient mismatch (PPM) were observed, and only 2 patients had moderate PPM. Median aortic root diameters at the level of sinus of Valsalva and sinotubular junction were 32 (29-35) mm and 33 (30-36) mm, respectively, at discharge, and were 33 (30-36) mm, and 33 (31-37) mm, respectively, at latest follow-up, with no cases of late pericardial patch aneurysm. CONCLUSIONS: ARE is a safe adjunct to AVR in patients with a small aortic annulus to prevent PPM. Retention of a pericardial collar and Teflon-buttressed sutures is an expedient, safe, and effective technique in reducing bleeding at the enlarged ventriculo-aortic junction. Autologous pericardial patch aortoplasty is not associated with late aneurysm/pseudoaneurysm formation.

Aortic Root Enlargement and Aortic Valve Replacement for Calcified Supravalvular and Valvular Aortic Stenosis in Homozygous Familial Hypercholesterolemia: A Case Report.

Familial homozygous hypercholesterolemia is a rare disease with diverse clinical presentations ranging from premature ischemic heart disease to aortic root stenosis but rarely presents with anginal symptoms due to supravalvular and valvular aortic stenosis. We report a 19-year-old male patient with familial homozygous hypercholesterolemia with progressive supravalvular and valvular aortic stenosis that ultimately required aortic root enlargement and aortic valve replacement using a mechanical prosthesis, despite aggressive medical therapy. Surgical importance of this rare condition is highlighted.

Successful Use of Intra-aortic Balloon Counterpulsation for Systemic Ventricular Failure Following Total Pericardiectomy for Calcific Chronic Constrictive Pericarditis.

We report two male patients aged 18 and 19 years, respectively, undergoing total pericardiectomy for chronic calcific constrictive pericarditis who developed systemic ventricular failure unresponsive to medical management following surgery. The failing circulation was successfully reestablished using intra-aortic balloon counterpulsation. Aortic counterpulsation facilitates recovery of ventricular function and appears to be a reasonable alternative in select instances of refractory cardiac failure following pericardiectomy.

Histopathology of the right ventricular outflow tract and the relation to hemodynamics in patients with repaired tetralogy of Fallot.

OBJECTIVE: To evaluate the relationship between myocardial histopathology and tissue Doppler imaging (TDI) variables of the right ventricle and postoperative peak systolic right-to-left ventricular pressure ratio (Prv/Plv) in patients undergoing intracardiac repair for tetralogy of Fallot (TOF). METHODS: Operatively resected crista supraventricularis muscle specimens from 93 patients undergoing intracardiac repair for TOF, aged 18 months to 26 years (mean, 7.02 ± 5.35 years) were subjected to light microscopy. TDI-derived parameters between the normal and abnormal categories of myocardium, the evolution of Prv/Plv, and its relationship to TDI-derived variables were tested using generalized linear random effects model using xtreg command. RESULTS: The incidence of myocyte hypertrophy, myocytolysis, and perivascular fibrosis was 89.2%, 83.8%, and 77.4%, respectively. Although tricuspid annular peak systolic excursion, peak myocardial velocity during systole (s'), and early diastolic basal lengthening of right ventricle (e') continued to improve among patients with myocardial hypertrophy, myocytolysis, and perivascular fibrosis, there was an absence of improvement of the late diastolic relaxation of right ventricular free wall (a') in patients with perivascular fibrosis. Although there was improvement of postoperative Prv/Plv in patients with myocardial fibrosis as compared with normal histology, the values were not statistically significant (ß [standard error] -0.07 [0.08], P = .3). CONCLUSIONS: The great majority of myocardial tissues in cyanotic TOF indicate pre-existing hypertrophic, degenerative, and fibrotic changes. Perivascular fibrosis affects the diastolic compliance of the right ventricle and may account for the absence of improvement of late diastolic relaxation (a') and greater postoperative Prv/Plv in the absence of a residual surgical lesion.

Comparison of grading of aortic stenosis between transthoracic and transesophageal echocardiography in adult patients undergoing elective aortic valve replacement surgeries: A prospective observational study.

Introduction: Intraoperative trans-esophageal echocardiography (TEE) has been found to underestimate severity of aortic stenosis (AS) compared to trans-thoracic echo (TTE). We conducted a prospective study comparing pre induction TTE and intra operative TEE grading of AS in patients posted for aortic valve replacement surgeries. Methods: Sixty patients with isolated AS who were undergoing aortic valve replacement were enrolled in our study. Baseline TTE was done and after induction of anesthesia, TEE was done. Mean gradient across aortic valve, peak jet velocity, aortic valve area (AVA) by continuity equation and dimensionless index (DI) were assessed in both. Results: Mean gradient decreased from 56.4 in TTE to 39.8 mm Hg in TEE leading to underestimation of AS in 74.5% of patients (P < 0.0). Mean of peak jet velocity also decreased from 500 in TTE to 386cm/s in TEE (P < 0.01). In 76 % of patients this led to reduction of AS grade from severe to moderate. Mean AVA was 0.67 cm2 in TTE and 0.69 cm2 in TEE. Though there was 0.02 cm2 increase, it was not statistically significant (P = 0.07). All the patients remained as severe AS in TEE. DI mean was 0.19 in both TTE and TEE (P = 0.14).It led to underestimation of severity in 6% of patients in TEE. Conclusion: Our study shows that AVA measurement by continuity equation and DI are reliable in grading aortic stenosis while performing intraoperative TEE. Mean gradient and jet velocity can be significantly reduced.

Can Echocardiographic Right Ventricular Function Parameters Predict Vasoactive Support Requirement After Tetralogy of Fallot Repair?

OBJECTIVE: To evaluate the role of echocardiographic right ventricular function parameters in predicting postoperative vasoactive inotrope requirement after tetralogy of Fallot repair. DESIGN: Prospective observational study. SETTING: A tertiary care hospital. PARTICIPANTS: Fifty-two children undergoing elective intracardiac repair. INTERVENTIONS: Comprehensive transesophageal echocardiography was performed before and after surgery. Fractional shortening, fractional area change, tricuspid annular plane systolic excursion (TAPSE), right ventricular myocardial performance index, tricuspid annular velocities (S', E', A'), and right ventricular global longitudinal strain and strain rate (RV Gls and RV Glsr) were measured. The ratio of peak systolic pressure of the right and left ventricles (Prv/lv) was measured directly from the surgical field pre- and post-repair. The inotrope requirement during first 24 postoperative hours was calculated using the mean Vasoactive-Inotropic Score (VIS). Pearson correlation analysis was used to study the relation between echocardiographic parameters and VIS as well as Prv/lv and VIS. Receiver operating characteristic analysis was used to study the predictive strength of parameters. MEASUREMENTS AND MAIN RESULTS: Among the measured parameters, both pre- and post-repair TAPSE had significant negative correlation with the mean VIS (p < 0.05). Both pre- and post-repair right ventricular myocardial performance index and S', E', A', RV Gls, RV Glsr, Prv/lv also had significant correlation with the mean VIS (p < 0.05). Of these, TAPSE, RV Gls, RV Glsr, and Prv/lv had significant predictive strength (p < 0.05) and reasonable sensitivity and specificity (area under the curve > 0.6) for predicting high mean VIS (VIS > 20). CONCLUSION: Tricuspid annular plane systolic excursion, RV Gls, RV Glsr, and Prv/lv could predict a postoperative high mean VIS with significant strength and reasonable sensitivity and specificity.

Bilateral Erector Spinae Plane Block for Acute Post-Surgical Pain in Adult Cardiac Surgical Patients: A Randomized Controlled Trial.

OBJECTIVES: To examine the analgesic efficacy of bilateral erector spinae plane (ESP) block compared with conventional treatment for pain after cardiac surgery in adult patients. DESIGN: A prospective, randomized, controlled, single-blinded study. SETTING: Single-center tertiary teaching hospital. PARTICIPANTS: One hundred and six adult patients undergoing elective cardiac surgery with cardiopulmonary bypass. INTERVENTIONS: Patients were randomized into 2 groups. Patients in group 1 (ESP block group, n = 53) received ultrasound-guided bilateral ESP block with 3 mg/kg of 0.375% ropivacaine before anesthesia induction at the T6 transverse process level. Patients in group 2 (paracetamol and tramadol group, n = 53) received paracetamol (1 gm every 6 hours) and tramadol (50 mg every 8 hours) intravenously in the postoperative period. The primary study outcome was to evaluate pain at rest using an 11-point numeric rating scale (NRS). Mann-Whitney U test was used for comparing NRS scores. MEASUREMENTS AND MAIN RESULTS: The postoperative pain level after extubation and duration of analgesia during which NRS was < 4 of 10 was compared between the groups. The median pain score at rest after extubation in group 1 was 0 of 10 until hour 6, 3 of 10 at hour 8, and 4 of 10 at hours 10 and 12 postextubation. These were significantly less in comparison with group 2 (p = 0.0001). Patients in group 1 had a significantly higher mean duration of analgesia (8.98 ± 0.14 hours), during which NRS was < 4 of 10, compared with group 2 (4.60 ± 0.12 hours) (p = 0.0001). CONCLUSION: ESP block safely provided significantly better pain relief at rest for longer duration as compared to intravenous paracetamol and tramadol.

Randomized Controlled Trial of Heparin Versus Bivalirudin Anticoagulation in Acyanotic Children Undergoing Open Heart Surgery.

OBJECTIVE: To determine the safety and efficacy of bivalirudin as an anticoagulant for pediatric open heart surgery (OHS) and to determine its appropriate dosage for this purpose. DESIGN: Prospective, randomized controlled trial. SETTING: Tertiary care hospital. PARTICIPANTS: Fifty acyanotic children aged 1-12 years undergoing OHS. INTERVENTIONS: The children were randomized to receive either 4 mg/kg of heparin (n = 25, group H) or 1 mg/kg of bivalirudin bolus followed by 2.5 mg/kg/h infusion (n = 25, group B) as the anticoagulant. The doses were adjusted to maintain activated clotting time (ACT) above 480 seconds. At the conclusion of surgery, protamine (1.3 mg/100 U of heparin) was administered to children in group H. MEASUREMENTS AND MAIN RESULTS: The children were comparable in both groups with regard to demographic characteristics. The mean age and weight were 51.5 months and 13.4 kg in group H, and 59.3 months and 13.4 kg in group B. The dose of anticoagulant required was 4.0 ± 0.2 mg/kg in group H and 1.7 ± 0.2 mg/kg followed by 3.0 ± 0.7 mg/kg/h infusion in group B (p < 0.001). One child in group H required an additional dose compared to 13 (54.2%) children in group B. Intraoperatively, the ACT achieved was higher in group H compared to group B (p < 0.05). The ACT returned to baseline value after protamine administration in group H, but it remained elevated for 2 hours after termination of cardiopulmonary bypass (CPB) in group B (p < 0.01). The ACT was higher in group B compared to group H for 6 hours after termination of CPB (p < 0.05). Heparin prolonged the onset of clotting, decreased the rate and strength of thrombus formation, and inhibited platelet function to a greater extent than bivalirudin on viscoelastic coagulation testing. The total duration of surgery was prolonged in group B. The postoperative chest tube drainage was similar in group B (4.9 mL/kg) as in group H (5.9 mL/kg) in spite of higher ACT. The transfusion requirements were similar. No adverse event occurred in any patient. CONCLUSION: Bivalirudin is a safe and effective anticoagulant for pediatric OHS. Though it is not suitable as a routine anticoagulant for this purpose, it may be used as a heparin alternative in instances when heparin cannot be used. The dose required to maintain ACT for more than 480 seconds was 1.7 ± 0.2 mg/kg followed by 3.0 ± 0.7 mg/kg/h infusion. The ACT remained elevated for 2 hours after stopping the infusion. Bivalirudin did not increase postoperative bleeding and transfusion requirement.

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.