Unilateral Pulmonary Hypertension Research Articles

Successful surgical correction of anomalous origin of the left pulmonary artery from the ascending aorta in a 16-year-old boy with Fallot's tetralogy

Tetralogy of Fallot (TOF) is a frequently encountered congenital heart defect, and the detailed diagnostic criteria are well established. There may be other anomalies associated with TOF, but the anomalous origin of the left pulmonary artery (LPA) from the ascending aorta (AOPA) is a rare one. The diagnosis of this anomaly, which may be mistaken for the absence of the LPA, should be made in early life to avoid unilateral pulmonary hypertension and also for appropriate surgical planning. We are reporting a case of a 16-year-old child, with the diagnosis of TOF associated with anomalous origin of the LPA from the AOPA who underwent a one-stage surgical correction of this anomaly.

Çıkan Aortadan Anormal Kaynaklanan Sağ Pulmoner Arter, Aortopulmoner Pencere ve Kesintili Arkus Aorta Birlikteliği: Tek 3D Yama ile Başarılı Cerrahi Düzeltme

Anomalous origin of the right pulmonary artery from the ascending aorta (AORPA) is a rare congenital heart defect and generally associated with other cardiac anomalies. Patients with AORPA have high pulmonary fl ow results in congestive heart failure and unilateral pulmonary hypertension. Thus, it is frequently a fatal malformation in the neonatal or early infancy periods if early surgical repair is not performed. Herein, we report a 1.5 month-old girl who was diagnosed with AORPA associated with aortopulmonary window and interrupted aortic arch and successfully operated using a single pericardial xenograft 3D patch.

Original rat model of high kinetic unilateral pulmonary hypertension surgically induced by combined surgery

The characteristic morphologic lesions observed in the lungs of patients with congenital cardiac anomalies have not been closely modeled in rat shunt-related models, except for the reversible grade 1 changes. The present study reported an original rat model of unilateral pulmonary hypertension surgically induced by combined surgery to reproduce more advanced pulmonary vascular lesions. The right pulmonary artery was ligated through a right posterolateral thoracotomy, and a cervical shunt was established 1 week later. The immediate and chronic effects on the pulmonary hemodynamics were evaluated through right heart catheterization immediately after and at 8 and 12 weeks postoperatively. The morphologic changes in pulmonary vasculature were analyzed after staining with hematoxylin-eosin and modified Weigert's method. The right ventricular hypertrophy index was calculated and artery blood gas analysis performed. A pulmonary hypertensive status was successfully induced immediately after cervical surgery and progressively aggravated into a borderline state with disease course advancing. Pulmonary vasculopathy demonstrated a transition from reversibility (muscularization, intimal proliferation of grade 1-2) at 8 weeks to irreversibility (intimal fibrosis, entirely luminal occlusion, grade 3) at 12 weeks postoperatively. Conspicuous right ventricular hypertrophy and decreasing partial arterial pressure of oxygen were also observed. The present shunt-related model successfully simulated a hypertensive status in pulmonary circulation and reproduced the characteristic transition of pulmonary vasculopathy from reversibility to irreversibility within a relatively short period. Thus, this model could offer an alternative with low mortality and high reproducibility for investigations on the underling mechanisms of shunt-related pulmonary hypertension.

Successful Treatment of an Adult Patient with an Aortopulmonary Window and Severe Unilateral Pulmonary Hypertension

A 40-year-old woman with an aortopulmonary window combined with a severe stenosis of the right pulmonary artery was successfully treated by surgical closure of the defect and pulmonary artery patch plasty of the pulmonary stenosis. Even though the vasculature of the left lung was severely damaged preoperatively, the resulting pressure in the lung after surgical correction was only mildly elevated.

Aortopulmonary window with unilateral pulmonary hypertension

Aortopulmonary window with unilateral pulmonary hypertension

An Adult with Truncus Arteriosus and Unilateral Pulmonary Hypertension

We report a young man who has persistent truncus arteriosus (TA), severe truncal regurgitation and unilateral pulmonary hypertension. Our patient had palliative main pulmonary artery (PA) banding done during infancy that was not followed by definitive corrective surgery. Unilateral irreversible left sided pulmonary hypertension developed due to migration of the PA band to the right PA. The patient presented to us with infective endocarditis of the truncal valve. This had resolved with medical treatment. Discussion was made on general management of TA and specific difficult management issues of palliated TA in adult, as found in our patient.

Counterpoint: Chronic Hypoxia-induced Pulmonary Hypertension does not Lead to Loss of Pulmonary Vasculature

Exposure of native sea level dwellers to chronic hypoxia due to migration to high altitude leads to the development of increased pulmonary vascular resistance causing pulmonary hypertension. In some susceptible individuals this progressively worsens causing right ventricular failure and ultimately

Tetralogy of Fallot with Anomalous Origin of the Right Pulmonary Artery from the Ascending Aorta and Hypoplastic Left Pulmonary Artery

A case of tetralogy of Fallot associated with anomalous origin of the right pulmonary artery from the ascending aorta and hypoplastic left pulmonary artery was successfully repaired. Following the simultaneous procedure with banding of the right pulmonary artery and replacement of modified Blalock-Taussig shunt to the left pulmonary artery at 34 days of age, the intracardiac repair was performed successfully at 1 year and 10 months of age. The patient was well 6 months postoperatively, without unilateral pulmonary hypertension.

Surgically induced unilateral pulmonary hypertension: time-related analysis of a new experimental model

Patients with irreversible pulmonary vascular obstructive disease caused by pulmonary hypertension due to congenital heart defects are considered either inoperable or only candidates to lung transplantation. This study evaluated an experimental model of surgically induced unilateral pulmonary hypertension. In eight pigs, 2-months-old, the left pulmonary artery was divided at the origin and end-to-side anastomosed to the descending thoracic aorta through a left thoracotomy. In this way, increased pulmonary blood flow in the right lung and systemic perfusion pressure and oxygenation in the left lung were obtained. After an interval of 6-12 weeks the animals underwent cardiac catheterization and were then sacrificed. Histological examination was done on both the lungs. The mean left-to-right shunt through the left pulmonary artery diminished from 58.9+/-9.6% at the end of the procedure to 4.5+/-1.5% at the latest hemodynamic evaluation (P<0.01). Pressures and saturations remained identical in aorta and left pulmonary artery, without reduction (NS) with FiO(2)=1.0 ventilation; in the right pulmonary artery there was a mild elevation of the pressures, but still responsive (P<0.05) to FiO(2)=1.0 ventilation. Lung histology showed normal right pulmonary arteries, but irreversible vascular lesions like intimal fibrosis, medial hypertrophy, vascular occlusions, plexiform and dilatation lesions in all the left lungs. The lung exposed to systemic pressure and oxygenation develops irreversible vascular lesions typical of pulmonary vascular obstructive disease. The lung exposed to increased flow shows only mild elevation of the arterial pressure, remains responsive to oxygen vasodilatation, and displays normal histology.

Unilateral Pulmonary Hypertension as a Result of Chronic High Flow to One Lung

The patient presented is a 27-month-old male with complex congenital heart disease consisting of severe left ventricular outflow tract obstruction and ventricular septal defect who had undergone a pulmonary trunk-to-aorta graft and a pulmonary artery banding procedure as a neonate. Sometime after this repair, but at least 15 months prior to presentation to this institution for placement of an aortic homograft, the pulmonary trunk band apparently slipped and migrated over the right pulmonary artery, severely limiting blood flow to the right lung and increasing flow to the left. Severe pulmonary hypertension developed, with a main pulmonary artery pressure of 94/53 mm Hg. We present clinical and radiographic evidence that the resulting chronic high blood flow and pressure in the left lung ultimately resulted in hypoperfusion of that lung, presumably secondary to chronic vascular changes with greatly increased vascular resistance. Upon surgical repair and removal of the constrictive band from the previously banded right PA, blood flow was increased to the low resistance right lung causing right-sided unilateral pulmonary edema, ventilation/perfusion mismatching, and severe hypoxemia. Perfusion studies documented that less than 10% of blood was directed to the left lung, with greater than 90% to the right. Perfusion studies 9 months postoperatively continued to demonstrate minimal blood flow to the left lung. Discussion focuses on the effects of mechanical forces and the interaction with hypoxia in causing pulmonary vascular remodeling.

Congenital absence of the right pulmonary artery: Report of a case in a five month old infant, with suggestive evidence of unilateral pulmonary hypertension ∗

The clinical history and anatomic findings in a case of isolated congenital absence of the right pulmonary artery are described and the literature reviewed. Medial hypertrophy and narrowing of the lumen of small arteries only in the lung supplied by the pulmonary artery, together with hypertrophy of the right ventricle, are interpreted as evidence of unilateral pulmonary hypertension. It is suggested that hypertension in the left lung may be the result of vasoconstriction in response to increased blood flow.