Pulmonary arterial compression syndrome caused by false aneurysm of left ventricular outflow tract

A 29 year old man experienced exertional dyspnea and coughing 3 1/2 years after insertion of a Brauwald-Cutter aortic valve prosthesis. Clinical examination suggested pulmonary arterial hypertension, and cardiac catheterization revealed a saccular lesion apparently arising from the left ventricular outflow tract and producing compression of the right pulmonary artery. Origin from the left ventricular outflow tract just under the aortic ring was confirmed at operation. The lesion apparently arose from an anular excavation related to previous endocarditis with abscess formation. Reported cases of similar aneurysmal lesions are briefly reviewed, and other known causes of the pulmonary arterial compression syndrome are discussed.     

Contractile properties of intralobar pulmonary arteries and veins in the fetal lamb model of congenital diaphragmatic hernia

BACKGROUND/PURPOSE: Pulmonary hypertension plays a significant role in the pathophysiology of congenital diaphragmatic hernia (CDH). Although there has been an intensive research effort directed at mediators that may cause pulmonary vasoconstriction, no single agent has been identified. The authors hypothesize that there may be an alteration in the cGMP-nitric oxide (NO) pathway of vasodilatation contributing to the pulmonary hypertension observed in CDH. The purpose of these studies is to begin to elucidate vasoactive properties of pulmonary vessels with particular attention to the cGMP-NO pathway of vasodilatation in fetal lambs with CDH. METHODS: Fourth-generation pulmonary arteries and pulmonary veins were dissected from both right and left lungs of eight, 139-day gestational fetuses with surgically created CDH. Vessels were studied with standard isolated tissue bath techniques. Experiments examined basal release of NO in endothelium-intact PVs and PAs of both right and left lungs by measuring the contractile force of vessels constricted with norepinephrine (NE) in the presence and absence of the nitric oxide synthase (NOS) inhibitor N(omega)-nitro-L-arginine (L-NA). Concentration-response curves to the vasodilating agents zaprinast and A23187 were also obtained in vessels contracted by NE. RESULTS: Left and right pulmonary artery responses to NE are enhanced over those of historic controls. Pretreatment of left pulmonary arteries with L-NA enhances the vasoconstrictor response to NE, whereas right PAs show no increased response. Relaxation responses to A23187 and zaprinast, in both left and right pulmonary arteries were not different from control lambs. Relaxation responses of both left and right pulmonary veins to A23187 and zaprinast are blunted compared with controls. This blunting is significantly more in left pulmonary veins than right. Further, right but not left pulmonary veins display enhanced vasoconstrictive response to NE after L-NA pretreatment. CONCLUSIONS: The NO-cGMP pathway of vasodilatation is abnormal in the near term, fetal lamb with CDH. These abnormalities were most apparent in pulmonary veins and may reflect abnormal NOS activity or content between left and right lungs of the fetal lamb with CDH. Pulmonary arteries from CDH lambs have basal and stimulated NO release equal to that of historic controls but appear to be hypersensitive to exogenous vasoconstrictors.     

Changes of vasoactive peptides and effects of inhaled nitric oxide after pneumonectomy

To clarify the role of vasoactive peptides in the physiologic response to pneumonectomy, we investigated the changes of atrial (A-type) natriuretic peptide (ANP). C-type natriuretic peptide (CNP), and endothelin-1 (ET-1) levels in the lung and blood after pneumonectomy and the effects of inhaled nitric oxide (NO; 5 ppm) after pneumonectomy in beagle dogs. The concentrations of these peptides in the lung and blood were measured by radioimmunoassay. The dogs in group A (n = 10) were observed without NO inhaling after right pneumonectomy, and the dogs in group B (n = 5) were observed with NO inhaling from 120 to 180 min after right pneumonectomy. After the thoracotomy, right lung tissue was resected for the pre-operative histological control. Tissue from the left lung was obtained at 120 min (5 dogs in group A), at 180 min (5 dogs in group A), and after 60 min of NO inhalation (group B) for the post-operative histological material. Peripheral blood was collected from the femoral artery. The pulmonary arterial pressure (PAP) was significantly increased after pneumonectomy, but rapidly decreased to the same level as the pre-operative stage after NO inhalation. Increases of plasma ANP, lung ANP and lung CNP levels occurred after pneumonectomy, while the ET-1 level was unchanged. Inhaled NO rapidly reduced the plasma ANP, lung ANP and lung CNP. These results indicate that both ANP and CNP act to maintain normotensive homeostatic balance in the pulmonary circulation.     

Etest for routine clinical antimicrobial susceptibility testing of rapid-growing mycobacteria isolates

Tumors depend on their blood supply for growth. The blood supply to metastatic neoplasia of lung is usually from the pulmonary circulation or both the pulmonary and systemic circulation. The antineoplastic effect of pulmonary artery occlusion was investigated in a rat model of methylcholanthrene-induced metastatic pulmonary sarcoma. Left pulmonary artery ligation was performed on day 7 after tumor inoculation, and animals were sacrificed on day 14. The tumor burden of the left lung decreased 44% when compared with the control group. The survival of non-tumor-bearing rats undergoing left pulmonary artery ligation for 24 hours followed by right pneumonectomy after 2 weeks was also studied. No significant lung damage after a period of left pulmonary artery ligation was seen, as evidenced by both survival after contralateral right pneumonectomy and histology. Balloon occlusion of pulmonary artery, together with regional chemotherapy for patients with lung metastases, may warrant investigation.     

Distance and the presentation of visual stimuli to birds

Hemodynamic factors have profound influences on blood vessels. To test the hypothesis that hemodynamic conditions modify the pattern of remodeling in response to injury, monocrotaline (MCT) injury in Sprague-Dawley rats was followed 1 week later by left pneumonectomy to increase blood flow to the right lung. Right pulmonary artery remodeling in these MCT plus pneumonectomy animals was compared with animals receiving MCT or pneumonectomy alone. Neointimal changes developed in more than 90% of all right lung intra-acinar vessels 5 weeks after MCT injury (4 weeks after pneumonectomy). Neointimal lesions did not develop in untreated animals or in animals receiving MCT or pneumonectomy only. Animals with a neointimal pattern of remodeling developed severe right ventricular hypertrophy (RVH) whereas animals with a medial hypertrophy pattern of remodeling (MCT only) developed moderate RVH compared with control animals. Neointimal lesions and RVH were similar whether injury preceded pneumonectomy or vice versa. To exclude the possibility that neointimal lesions resulted from injury plus post-pneumonectomy compensatory lung growth, rather than injury plus increased flow, a left subclavian-pulmonary artery anastomosis was substituted for pneumonectomy. Neointimal lesions and severe RVH developed in these animals but were not seen in animals receiving either MCT or anastomosis only. These studies demonstrate an important role for hemodynamics in determining the pattern of pulmonary vascular remodeling after injury.     

Progression of interproximal caries in the primary dentition

In the patients with invasion to the aortic window, we performed operation via median sternotomy combined with anteroaxillar thoracotomy. In such patients with T4 invasion, conventional pneumonectomy could not be performed because of the extensive invasion near the main pulmonary artery trunk. In these patients in this study, complete resection of the involved pulmonary artery could be performed using a vascular clamp without CP bypass. Operative technique was as follows: first, the pericardium was opened and taping of the aorta was applied. When the uninvolved part of the intrapericardial pulmonary artery was long enough to cut, we could use a stapling device, but the stapling device could not be used in many cases because the length of the uninvolved segment was too short to cut the left pulmonary artery. In order to carry out complete resection, it was necessary to clamp the central part of the main pulmonary artery diagonally from the left lower side to the right upper side. The pulmonary arterial stump was closed with continuous 4-0 monofilament mattress and over and over suture. We recommend an aggressive surgical approach for the tumor with invasion to the aortic window, because the prognosis is dismal in nonresected locally advanced lung cancer.     

Scimitar syndrome in infancy

OBJECTIVES: The objectives of this study were to determine the anatomic and physiological factors most responsible for the severe symptoms and poor prognosis of infants with scimitar syndrome. BACKGROUND: Whereas the diagnosis of scimitar syndrome is often made incidentally in older children and adults who undergo chest radiography for diverse reasons, infants in whom the diagnosis is made typically present with severe symptoms and have a poor prognosis. METHODS: The clinical, catheterization and imaging data of 13 consecutive infants with scimitar syndrome who underwent cardiac catheterization in the 1st 6 months of life were reviewed, with emphasis on the pulmonary artery pressure, pulmonary and cardiovascular anatomy, therapeutic interventions and outcome. RESULTS: Twelve of the 13 infants had pulmonary hypertension at the time of diagnosis. Six patients died despite specific treatment. Eleven of 13 infants had associated cardiac malformations and 9 had large systemic arterial collateral channels to the right lung. Seven patients had anomalies involving the left side of the heart, especially varying degrees of hypoplasia of the left heart or aorta, and six of these patients died. Ten patients underwent surgical or transcatheter therapy in the 1st year of life. Systemic arteries to the right lung were ligated in three patients and occluded by transcatheter embolization in four. Balloon angioplasty was carried out in two patients, one with stenosis of the left-sided pulmonary veins and one with stenosis of the anomalous right pulmonary vein. The latter had placement of a balloon-expandable stent. In both patients, pulmonary vein stenosis progressed. Six patients had surgical repair of associated cardiovascular anomalies, and two required repair of extracardiac congenital anomalies. Occlusion of the anomalous systemic arteries was generally associated with clinical improvement, but congestive heart failure and pulmonary hypertension recurred in those patients with associated cardiovascular anomalies, whose condition subsequently responded after correction of the shunt lesions. CONCLUSIONS: The severe symptoms and pulmonary hypertension found in infants with scimitar syndrome have many causes. Anomalous systemic arterial supply, pulmonary vein stenosis and associated cardiovascular anomalies play a significant role, and the ultimate outcome of individual infants depends on the feasibility of treating these anomalies in early infancy.     

Intravenous nitroglycerin in acute respiratory failure of patients with chronic obstructive lung disease, secondary pulmonary hypertension and cor pulmonale

We have studied the hemodynamic effects of an intravenous single dose of nitroglycerin in 13 patients with secondary pulmonary hypertension and Cor Pulmonale, during the acute course of respiratory failure and under assisted ventilation. We observed a significant decrease in systolic, diastolic and mean pulmonary arterial pressures, and in pulmonary resistance and systolic right ventricular work index, without any change in right or left pre-loads. The systolic arterial pressure decreased slightly, without any change in cardiac index or diastolic pressure. The arterial and mixed venous oxygen contents, and the pulmonary shunting ( Qs/Qt) were unchanged. These results suggest that nitroglycerin may be a useful therapy in patients in the acute stages of pulmonary hypertension resulting from chronic lung disease and under assisted ventilation. In addition, the lack of change in cardiac index, intrapulmonary shunting and oxygen content suggests that this decrease in pulmonary resistance is not linked with any deleterious effect in oxygen transfer.     

Right ventricular size is acutely decreased by inhaled nitric oxide in newborns with pulmonary hypertension

The pressure and volume demands of the right and left ventricles may dramatically change following selective pulmonary vasodilation in newborns with pulmonary hypertension. Thus, ventricular planimetry was performed by two-dimensional echocardiography in 35 newborns with lung disease and increased pulmonary vascular resistance who were treated with inhaled nitric oxide to determine the influence of therapy on right and left ventricular size and function. The end-diastolic and end-systolic areas of each ventricle were measured from apical 4-chamber images before, and 30 to 60 minutes after, the onset of 20 parts per million inhaled nitric oxide. Estimates of ventricular function were determined by the systolic decrease in ventricular area, (diastolic area - systolic area) x 100/diastolic area. Heart rate, systemic blood pressure, and left ventricular areas did not change. However, the oxygenation index, the proportion of right-to-left ductal shunt (nonrestrictive ductus arteriosus, n = 22), the systolic pulmonary arterial pressure (closed or restrictive ductus arteriosus, n = 13), and the right ventricular diastolic and systolic areas were decreased after nitric oxide inhalation. The baseline systolic decrease in left ventricular area was lower in a subgroup of patients who developed an increase in left ventricular diastolic area following nitric oxide inhalation. Thus, nitric oxide improves pulmonary hemodynamics and decreases right ventricular size in newborns with lung disease and pulmonary hypertension. However, newborns may develop an increase in left ventricular size if left ventricular function is decreased prior to therapy.     

Evaluation of pulmonary arterial trunk on frontal chest radiograph in patients with atrial septal defects

Atrial septal defect (ASD) is one of the most common congenital cardiac anomalies encountered in adulthood. The evaluation of the pulmonary hypertension in ASD is clinically important for operative indication and prognosis. The pulmonary vasculature in chest radiographs in patients with ASD is characterized as dilatation of the central pulmonary arteries and increase of the peripheral pulmonary vessels in patients without pulmonary arterial hypertension (PH) and constriction of the peripheral pulmonary arteries in those with pulmonary hypertension. While the dilatation of the main pulmonary artery occurs in the patients both with and without pulmonary hypertension, its precise radiographic evaluation with regard to the morphological and hemodynamic change of the right ventricle and pulmonary arteries has not been reported. This study was to determine if the contour of the main pulmonary artery segment of the cardiac silhouette in the conventional frontal chest radiograph could be used 1) as indicators of PH or raised right ventricular pressure and 2) as a reliable base for evaluation of the size of the right ventricule (RV) in ASD. The intersection of the line (line A) drawn tangentially to the lateral lower margin of the main pulmonary artery segment to the horizontal line at the left hemidiaphragm is closely related to the apex of RV as measured by right ventricular angiography in supine position. The ratios of the distance of the intersection from the midline of the frontal chest radiograph to the internal diameter of the left hemithorax in normal subjects were 0.50 +/- 0.08 (mean +/- standard deviation) for male and 0.54 +/- 0.09 for female. The ratio increased with increasing left-to-right shunt [0.59(Qp/QS < 2), and 0.71 (Qp/QS > 2)] and shows a tendency of decrease with raised right ventricular systolic pressure (0.52-0.64 in normal subjects and patients with mild raised right ventricular systolic pressure and 0.43 in patients with severe raised right ventricular systolic pressure). The measurement of the angle of the line A from the vertical line tends to show increasing decrease with raised pulmonary arterial and right ventricular systolic pressure (20.1 degrees +/- 4.9 in mild PH and 10.3 degrees +/- 4.1 in moderate to severe PH). The decrease of the angle of the line A to the vertical line was well correlated with conventional radiographic criteria of the right and left central pulmonary arteries of PH.(ABSTRACT TRUNCATED AT 400 WORDS)     

Ischemic preconditioning enhances donor lung preservation in the rat

BACKGROUND: Ischemic preconditioning achieved by brief periods of ischemia and reperfusion before a prolonged period of ischemia can significantly reduce the extent of cardiac damage in many mammalian species and human beings. In this study we used a rat model of single lung transplantation to show that ischemic preconditioning also occurs in the lung. METHODS: Rats randomly selected for ischemic preconditioning had their left main bronchus and pulmonary artery occluded for 5 minutes, followed by 10 minutes of reperfusion and ventilation. Lungs of control rats were ventilated for 15 minutes. The lungs were perfused with University of Wisconsin solution, then heart and lungs were excised en bloc and stored in University of Wisconsin solution at 0 degree C for 6 or 12 hours. After left pneumonectomy, the left lung of the donor was then implanted into the recipient via left thoracotomy. After 1 hour of ventilation and reperfusion, a right pneumonectomy was performed making the animal completely dependent on the transplanted lung. Samples of arterial blood from the left ventricle were then taken for arterial oxygen tension and arterial carbon dioxide tension determination. Water contents of the donor lungs were measured before and after reperfusion. Thiobarbituric acid reactive substances were measured in the right donor lung after storage. RESULTS: Lungs transplanted after 12 hours of storage had profoundly impaired gas exchange (arterial oxygen tension = 34 +/- 5; arterial carbon dioxide tension = 69 +/- 7 mm Hg) compared with the normal levels in the 6-hour storage group (arterial oxygen tension = 308 +/- 22; arterial carbon dioxide tension = 17 +/- 1 mm Hg). Ischemic preconditioning significantly improved gas exchange in the 12-hour storage group (arterial oxygen tension = 83 +/- 11; arterial carbon dioxide tension = 40 +/- 4 mm Hg). Ischemic preconditioning also significantly decreased thiobarbituric acid reactive substances formation at both 6- and 12-hour storage. CONCLUSIONS: These results show that the phenomenon of ischemic preconditioning occurs in the lung and that it may reduce injury to the donor lung during prolonged cold ischemic storage.     

Unidirectional valve patch for repair of cardiac septal defects with pulmonary hypertension

BACKGROUND: Congenital septal defects with a large left-to-right shunt often cause pulmonary hypertension, which complicates surgical repair of the defects. METHODS: Twenty-four patients with congenital cardiac septal defects and severe pulmonary hypertension had operation to close the septal defect using a unidirectional valve patch during a 3-year period. The ratio of systolic pulmonary artery pressure to systolic arterial blood pressure was near to or more than 1.0 in all patients. RESULTS: Two patients died in the hospital after operation, and there have been no deaths during intermediate term follow-up. Mean pulmonary artery pressure decreased from 80 +/- 12 mm Hg to 56 +/- 18 mm Hg. The ratio of pulmonary artery pressure to systemic arterial pressure dropped from 1.1 +/- 0.1 mm Hg to 0.7 +/- 0.1 mm Hg. The unidirectional valve patch functioned allowing right to left shunting in 4 patients with a systolic pulmonary artery pressure more than systolic arterial blood pressure immediately after closure of a septal defect. The patch sealed or was effectively closed by the third postoperative day. There was impressive improvement in symptoms and exercise tolerance after operation during the 3-month to 3-year (mean, 1.1 year) follow-up period. CONCLUSIONS: The unidirectional valve patch is useful for management of patients having operation to close cardiac septal defects in the presence of severe pulmonary hypertension.     

Platelet kinetics in congenital heart disease

The survival of 111indium labelled platelets has been determined in a series of 47 subjects comprising nine with cyanotic congenital disease (Eisenmenger's syndrome), seven with congenital heart disease associated with left to right shunts, six with primary pulmonary hypertension, six with peripheral vascular disease, 11 with cardiac disorder associated with low cardiac output and eight normal volunteers. Compared with the value in the normals of 9.5 days, mean survival was significantly shortened in those with Eisenmenger's syndrome (8.4 days) and with peripheral vascular disease (8.5 days). It was normal in patients with left to right shunts (9.5 days). Gamma camera imaging in selected patients failed to reveal any abnormal sites of deposition of labelled platelets except in one patient with peripheral vascular disease who had bilateral abnormal activity in his lower limbs and a shortened platelet survival (8.0 days). From theoretical considerations, it was concluded that the reduction in platelet survival in Eisenmenger's syndrome was such that, had it been the result of pulmonary intravascular platelet deposition, abnormal activity should have been visible on chest scanning with the gamma camera. The absence of scintigraphic evidence of abnormal platelet deposition in the lungs of these patients, combined with the linear configuration of their platelet survival curves, suggests that the accelerated platelet destruction is in the reticuloendothelial (RE) system rather than intravascular. Indirect evidence in favour of increased RE destruction of platelets in Eisenmenger's syndrome was the finding of an approximate doubling of intrasplenic platelet transit time, indicating abnormal platelet pooling within the spleen.     

Respiratory insufficiency and absent left radial pulse after hemicolectomy

A 65 year old female developed right thoracic pain, productive cough and fever four weeks after hemicolectomy because of a cancer of the sigmoid. In spite of antibiotic treatment the condition of the patient deteriorated and she was admitted to the hospital with pneumonia of an upper lobe. Chest X-ray visualized prominent proximal pulmonary arteries. Progressive respiratory failure developed and blood gas analysis revealed hypocapnic hypoxemia. The patient had to be intubated and ventilated mechanically. Later, left arm blood pressure measurements could no longer be taken and the radial pulse was missing. Thereafter, an ischemic syndrome of the right leg developed. Embolectomy from the superficial femoral artery was carried out the same day. The patient died five days later. Autopsy revealed an almost complete occlusion of the pulmonary arteries. The organization of thrombotic material indicated recurrence. Emboli were also found in the systemic circulation. A large patent foramen ovale together with signs of pulmonary arterial hypertension are indicative of paradoxical thromboembolism.     

Completion right lower lobectomy for recurrence after left pneumonectomy for metastases

Resection of pulmonary recurrences on the residual lung after pneumonectomy for metastases is exceptional. A 37-year-old woman was submitted to left extended pleuro-pneumonectomy after left leg amputation for fibrosarcoma. At 43 months later, a wedge resection on the right lower lobe was performed followed 32 months later by a further wedge resection in the same lobe. A completion right lower lobectomy for a new recurrence was performed 17 months after the last pulmonary resection. The patient did not develop postoperative complications. She is still alive and free of disease 10 years and 9 months after pneumonectomy and 36 months after completion lobectomy on the residual lung. In highly selected patients, aggressive surgery for metastases on the residual lung can be successfully performed and it can improve survival.     

Horseshoe lung: demonstration by electron-beam CT

Horseshoe lung is a rare pulmonary anomaly characterized by fusion of the posterobasal portions of the right and left lungs behind the pericardial reflection, anterior to the aorta. The majority of reported cases occur in conjunction with scimitar syndrome, including hypoplasia of the right lung, anomalous right pulmonary venous return and systemic arterial supply to the lung. Horseshoe lung is usually diagnosed on pulmonary arteriography when the right inferior pulmonary artery crosses the midline and extends to the left lung base. Bronchography is also diagnostic when the branch of horseshoe portion arises from the right bronchus and passes within the lung parenchyma to midline of the lung tissue. The only described CT finding of horseshoe lung is the contiguity of the right and left lungs behind the heart. Most cases are infants under 12 months of age and CT images are severely hampered by respiration motion artefacts. Such artefacts are minimized by using electron-beam computed tomography, allowing a more detailed CT appearance of horseshoe lung in this case.     

Pathophysiological considerations concerning uni- and biventricular mechanical cardiac assist

Mechanical assisted circulation by the means of cardiac assist devices is a routine procedure in modern cardiac surgery and cardiology. We investigated the impact of mechanical unloading on regional myocardial "stunning" and the influence of assisted circulation on left heart and right heart failure persevered by an ultimate addition of pulmonary hypertension in experimental set ups. We found that mechanical unloading either during ischemia or in the early reperfusion phase attenuates stunning and enhances the return of synchronous heart performance. In our global dysfunction model we showed that the right heart is dispensable. Sufficient inflow to the left heart is provided unless pulmonary hypertension is present. Also additional left heart support can not overcome the deleterious situation and in select cases only additional right heart support can prevent the "low LVAD output" syndrome. We conclude that mechanical assisted circulation and mechanical unloading are beneficial in case of regional and global dysfunction persevered by pulmonary hypertension, however, the knowledge about interactions of assist systems and the circulation has to be improved in order to optimize clinical assist device performance.     

Postpneumonectomy pulmonary edema. A retrospective analysis of associated variables

STUDY OBJECTIVE: Evaluate the correlation between intravenous fluid administration and postpneumonectomy pulmonary edema. DESIGN: Retrospective chart review. SETTING: Large multispecialty group practice hospital. PATIENTS: Adults who had a pneumonectomy performed between 1977 and 1988. MEASUREMENTS AND RESULTS: Patients were identified who had postpneumonectomy pulmonary edema (PPE). Fluid administration and fluid balance information was found in records and compared with age- and sex-matched control patients who did not develop PPE. The side of pneumonectomy was noted for patients in each group. Autopsy findings were recorded for patients who died. Twenty-one patients met PPE criteria. No significant difference was found between groups for fluid administration or fluid balance. Patients who had right pneumonectomy had a significantly higher incidence of PPE. Patients with PPE had a 100 percent mortality rate and histologic evidence of the adult respiratory distress syndrome (ARDS) at autopsy. CONCLUSIONS: PPE is caused by noncardiogenic pulmonary edema rather than excess intravenous fluid administration. There is a greater incidence of the syndrome with right pneumonectomy for unknown reasons. The mortality rate is high despite interventions for ARDS.     

Pulmonary hypertension in patients with obstructive sleep apnea syndrome

BACKGROUND: Obstructive sleep apnea syndrome (OSAS) is associated with an increased cardiovascular morbidity, including pulmonary hypertension. Little is known about factors influencing the degree of pulmonary hypertension and left ventricular dysfunction in patients with OSAS, especially in the absence of concomitant lung disease. METHODS: Right heart catheterization, arterial blood gas analysis, and pulmonary function tests were performed in 92 consecutive patients (81 men and 11 women; mean +/- SD age, 53.1 +/- 11.0 years) with polysomnographically verified OSAS, in whom clinically significant lung disease was excluded. RESULTS: Eighteen patients (20%) had mild pulmonary hypertension; 8 (44%) of them also had increased pulmonary capillary wedge pressures (Ppew). Left ventricular dysfunction was associated with arterial hypertension. Only Ppcw (r = 0.51; P < .001) and the percentage of time during sleep spent with an oxygen saturation below 90% (as an indicator of the severity of OSAS) (r = 0.34; P = .003) were significantly and independently associated with pulmonary artery pressure. CONCLUSIONS: Obstructive sleep apnea syndrome can cause mild pulmonary hypertension, even in the absence of pulmonary disease. In these patients, pulmonary hypertension is of the postcapillary type, or-in patients with normal left ventricular function-strongly related to the severity of OSAS. Our findings indicate that OSAS may constitute an important, and independent, risk factor for pulmonary hypertension.     

Chronic pulmonary thromboendarterectomy complicated by antithrombin III deficiency and antiphospholipid syndrome

Pulmonary thromboendarterectomy was performed on two patients with chronic pulmonary thromboembolism showing thrombotic tendency. Patient 1 was a 25-year-old male with the disease complicated by congenital antithrombin III deficiency. Patient 2 was a 21-year-old male with the disease complicated by antiphospholipid syndrome. Both patients were admitted to the center upon showing dyspnea. Lung perfusion scintigraphy revealed multiple defects in the right and left lungs. Pulmonary arteriography showed occlusion and stenosis from lobar to segmental arteries. Cardiac catheterization showed marked pulmonary hypertension. Pulmonary angioscopy confirmed the presence of organized thrombi while an intravascular ultrasound revealed a thickening of the pulmonary arterial walls in both lungs. After the insertion of an inferior vena cava filter in each patient, surgery was performed. Following a median sternotomy, a cardiopulmonary bypass was utilized to induce deep hypothermia at a pharyngeal temperature of 16 degrees C, after which a thromboendarterectomy of the bilateral pulmonary arteries was performed under intermittent circulatory arrest. A large amount of organized thrombi was extracted from these arteries. After surgery, both patients showed good postoperative outcome with improved blood flow in both lungs, reduced pulmonary arterial pressure and increased cardiac output.