Misalignment of lung vessels: diagnostic role of conventional histology and immunohistochemistry.

Misalignment of lung vessels represents a rare congenital anomaly that may cause respiratory failure in the newborn. It is characterized by abnormal position of pulmonary veins and venules that lie adjacent to arteries and bronchi, and it is usually associated with a decreased number of alveolar capillaries (i.e., alveolar capillary dysplasia), although these two conditions have been separately described. Awareness of this anomaly is required by pathologists because it can be easily overlooked on lung biopsy or autopsy, and because definite diagnosis relies on histology. We report the case of a newborn male baby who developed respiratory distress 18 h after an uncomplicated delivery. The patient died on the 7th day, after high frequency oscillatory ventilation, nitric oxide inhalation and extracorporeal membrane oxygenation were unsuccessful. On autopsy, histology and immunohistochemistry demonstrated diffuse changes, fulfilling diagnostic criteria of misalignment of lung vessels and of alveolar capillary dysplasia in both lungs, with muscularization of very peripheral pulmonary arteries and a prominent interstitial and periadventitial fibrosis. Diffuse distribution of vessel misalignment could explain the rapid onset of respiratory failure, and the presence of diffuse fibrosis might have contributed to irreversible respiratory dysfunction by impairment of lung parenchyma extensibility.

Flail Tricuspid Valve in an Adult Patient with Congenitally Corrected Transposition of the Great Arteries.

We describe a case of a 50-year-old woman with congenitally corrected transposition of the great vessels, in whom severe left-sided tricuspid (systemic atrioventricular) valve insufficiency was the only associated anomaly. The tricuspid valve was dysplastic and abnormally oriented toward the interventricular septum, without the downward displacement of Ebstein's anomaly. The mechanism of atrioventricular regurgitation was unusual in that it consisted of the rupture of chordae tendineae of both the anterior and septal leaflets. The left-sided tricuspid valve was replaced with a St. Jude prosthesis and the postoperative course was uneventful.

Two decades of experience with the Ross operation in neonates, infants and children from the Italian Paediatric Ross Registry.

OBJECTIVE: Children undergoing Ross operation were expected to have longer autograft, but shorter homograft durability compared with adults. In order to define the outcome in the second decade after Ross operation in children, a nationwide review of 23 years of experience was undertaken. METHODS: 305 children underwent Ross operation in 11 paediatric units between 1990 and 2012. Age at surgery was 9.4±5.7 years, indication aortic stenosis in 103 patients, regurgitation in 109 and mixed lesion in 93. 116 (38%) patients had prior procedures. Root replacement was performed in 201 patients, inclusion cylinder in 14, subcoronary grafting in 17 and Ross-Konno in 73. RESULTS: There were 10 (3.3%) hospital and 12 late deaths (median follow-up 8.7 years). Survival was 93±2% and 89±3% and freedom from any reoperation was 76±3% and 67±6% at 10 and 15 years. 34 children had autograft 37 reoperations (25 replacement, 12 repair): three required transplantation after reoperation. Freedom from autograft reoperation was 86±3% and 75±6% at 10 and 15 years. 32 children had right heart redo procedures, and only 25 (78%) conduit replacements (15-year freedom from replacement, 89±4%). Prior operation (p=0.031), subcoronary implant (p=0.025) and concomitant surgical procedure (p=0.004) were risk factors for left heart reoperation, while infant age (p=0.015) was for right heart. The majority (87%) of late survivors were in NYHA class I, 68% free from medication and six women had pregnancies. CONCLUSIONS: Despite low hospital risk and satisfactory late survival, paediatric Ross operation bears substantial valve-related morbidity in the first two decades. Contrary to expectation, autograft reoperation is more common than homograft.

The prenatal diagnosis of, and short-term outcome for, patients with congenitally corrected transposition.

Congenitally corrected transposition is a rare congenital anomaly, with only a few cases diagnosed and reported prenatally even in the largest fetal series. To determine the morphologic features and outcome for the lesion as recognized during fetal life, we reviewed the fetal and postnatal echocardiograms and medical records of 11 consecutive cases of congenitally corrected transposition. These were identified among 230 (4.7%) consecutive cases of structural cardiac disease referred to our fetal cardiology unit over a period of 4 years. The mean gestational age at diagnosis was 24.7 weeks. Reasons for referral were suspected complete transposition, abnormal position of the heart, and bradyarrhythmias. Associated cardiac lesions included an abnormal cardiac position in 6 cases, ventricular septal defect in 8, obstruction of the subpulmonary outflow tract in 6, tricuspid valvar displacement in 5, and complete atrioventricular block in 2. Only 3 of the cases had mild tricuspid regurgitation prior to birth. Termination was chosen in 4 cases with severe obstruction to pulmonary flow. Of the remaining cases, 2 patients died at 3 and 12 months after birth, respectively. Both developed significant tricuspid regurgitation associated with unexpected major arrhythmias. The remaining 5 patients are alive and relatively well at a mean follow-up of 25.4 months. An epicardial pacemaker was inserted in 1 because of complete atrioventricular block. We conclude that prenatal counseling must be guarded following the diagnosis of congenitally corrected transposition, even in fetuses with an apparently favorable state at initial examination. Some of these cases may undergo major and unexpected changes, particularly with regard to cardiac rhythm and tricuspid valvar function, with concomitant significant changes in prognosis.