Fibrosing mediastinitis causing pulmonary arterial hypertension without pulmonary venous hypertension. Clinical and necropsy observations

Clinical and morphologic observations are described in two patients with severe pulmonary arterial hypertension without pulmonary venous hypertension from fibrosing mediastinitis. In one patient, both main pulmonary arteries and one major pulmonary vein were severely narrowed by dense fibrous tissue; in the second patient, only the right main pulmonary artery was severely narrowed. Both patients had normal intrapulmonary arteries and normal pulmonary parenchyma. Of nine previously described necropsy patients with pulmonary hypertension due to fibrosing mediastinitis, seven had severe narrowing of multiple large pulmonary veins and in six of them the pulmonary hypertension was entirely due to pulmonary venous obstruction. In one other patient, the pulmonary hypertension was due to obstruction of one main pulmonary artery and several large pulmonary veins. Each of these seven previously described patients had severe changes in the small intrapulmonary arteries. Of the other two previously described patients with pulmonary hypertension from fibrosing mediastinitis, one had severe narrowing of only the main right pulmonary artery, and the other, of both main pulmonary arteries. Thus, although pulmonary arterial hypertension in patients with fibrosing mediastinitis is usually due to obstruction of multiple large pulmonary veins and to severe secondary changes in small intrapulmonary arteries, fibrosing mediastinitis can cause severe pulmonary hypertension by obstructing the right or both main pulmonary arteries.     

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.     

Alterations in pulmonary artery flow patterns and shear stress determined with three-dimensional phase-contrast magnetic resonance imaging in Fontan patients

OBJECTIVE: This study compares in vivo pulmonary blood flow patterns and shear stresses in patients with either the direct atrium-pulmonary artery connection or the bicaval tunnel connection of the Fontan procedure to those in normal volunteers. Comparisons were made with the use of three-dimensional phase contrast magnetic resonance imaging. METHODS: Three-dimensional velocities, flows, and pulmonary artery cross-sectional areas were measured in both pulmonary arteries of each subject. Axial, circumferential, and radial shear stresses were calculated with the use of velocities and estimates of viscosity. RESULTS: The axial velocities were not significantly different between subject groups. However, the flows and cross-sectional areas were higher in the normal group than in the two patient groups in both pulmonary arteries. The group with the bicaval connection had circular swirling in the cross section of both pulmonary arteries, causing higher shear stresses than in the controls. The disorder caused by the connection of the atrium to the pulmonary artery caused an increase in some shear stresses over the controls, but not higher than those found in the group having a bicaval tunnel. CONCLUSIONS: We found that pulmonary flow was equally reduced compared with normal flow in both patient groups. This reduction in flow can be attributed in part to the reduced size of the pulmonary arteries in both patient groups without change in axial velocity. We also found higher shear stress acting on the wall of the vessels in the patients having a bicaval tunnel, which may alter endothelial function and affect the longevity of the repair.     

Identification of autolysosomes directly associated with proteolysis on the density gradients in isolated rat hepatocytes

BACKGROUND: More than 40% of patients who undergo curative resection of advanced colorectal carcinoma can be expected to have recurrence of the disease. The most frequent sites of recurrence are the liver (33% of patients) and lung (22%). Interest has therefore focused on treating hepatic or pulmonary metastases, or both, to improve the outcomes of these patients. Although surgical resection has become an increasingly accepted treatment for resectable localized hepatic or localized pulmonary metastases from colorectal carcinoma, the value of aggressive surgery for the removal of both hepatic and pulmonary metastases from patients with primary colorectal carcinoma remains to be clarified. METHODS: Data on 30 patients who had undergone resection of both hepatic and pulmonary metastases from colorectal carcinoma were included in the study. RESULTS: Independent, significant prognostic features were found to be the time that hepatic or pulmonary metastases occurred and the distribution of pulmonary metastases. Median survival times were 30 months (range, 7-108 months) after resection of both hepatic and pulmonary metastases and 48.5 months (range, 11-149 months) after excision of the primary colorectal tumor. Actuarial 1-, 3-, and 5-year survival after resection of both hepatic and pulmonary metastases was 86.7%, 49.3%, and 43.8%, respectively. No perioperative mortality occurred. There were three cases of minor morbidity, which the authors considered acceptable. CONCLUSIONS: Resection of both hepatic and pulmonary metastases from colorectal carcinoma may help to prolong the survival of a small group of patients with these metastases.     

Variation in the size and distensibility of the pulmonary arteries in d-transposition of the great arteries

The relative size of the main pulmonary artery was determined from cineangiograms of 117 patients with d-transposition of the great arteries by calculating the ration between the diameters of the main pulmonary artery and aorta. The pulmonary artery was largest in patients with ventricular septal defect or patent ductus arteriosus, or both, because of increased pulmonary arterial pressure and flow. In patients with an intact ventricular septum or with left ventricular outflow tract obstruction, or both, the main pulmonary artery was approximately the size of the aorta. Two cases of d-transposition and gross dilatation of the main pulmonary artery and hypoplastic first branch pulmonary arteries are presented. In these cases the ratio between the diameters of the main pulmonary artery and aorta was greater than in any of the other 117 cases studied...     

Surgical treatment of pulmonary atresia with intact ventricular septum

Fifty-nine children with pulmonary atresia and intact ventricular septum underwent various forms of surgical treatment at the Hospital for Sick Children, Toronto, during 1950 to mid 1975. Twenty-three patients had pulmonary valvotomy, 15 direct, 2 indirect, and 6 both direct valvotomy and infundibulectomy. All died, 19 early and 4 late. Of 13 patients who received a systemic-pulmonary artery shunt, 4 combined with surgical atrial septectomy, there are only 2 long-term survivors both of whom were children who had had a Waterston anastomosis. Recently we have been treating infants with small right ventricles with balloon atrial septostomy at cardiac catherterization followed by a Potts anastomosis and pulmonary valvotomy. If the Potts anastomosis appears satisfactory the persistent ductus arteriosus is ligated. This scheme was used in 23 infants, with 4 early deaths and 2 late deaths. Of 17 survivors, further shunts were required in 4 children. One child has had a formal repair, with insertion of valves in both tricuspid and pulmonary areas. We believe that this operative combination of Potts anastomosis and pulmonary valvotomy offers the infant with pulmonary atresia and a small right ventricle a relatively low initial mortality and the possibility of right ventricular enlargement and subsequent repair.     

Effects of limited mouth opening capacity (trismus) on lung function

In the present study pulmonary function test data were obtained from 15 healthy volunteers and 15 patients with slightly impaired ventilation during both normal and maximally reduced opening of the mouth (trismus, intercuspid position). The aim of the study was to examine the effects of complete trismus on pulmonary function using objective and subjective parameters. In maximally reduced mouth opening, both groups showed an impairment of all subjective and objective pulmonary function test data. In healthy volunteers, the significant changes in the test data (p < 0.05) simulated mild to moderate pulmonary impairment, whereas patients with an already impaired pulmonary function showed a marked deterioration of their initial respiratory condition. The results of the subjective and objective parameters examined indicate that an intercuspid position (trismus) further aggravates pulmonary functional impairments. Complete trismus can be considered a risk factor to pulmonary function in patients using mouth-breathing as primary or supportive mode of respiration.     

The action of histamine on pulmonary vessels of cats and rats

1. The actions of histamine on pulmonary vascular smooth muscle have been studied in isolated cat and rat lungs perfused with blood, lobes of cat lung perfused in vivo and isolated strips of rat, cat and rabbit pulmonary artery. 2. In all the lung preparations histamine caused both dilatation and constriction. In the rat strips it caused both contraction and relaxation. Dilatation was only well shown when the vessels were in a prior constricted state. In any one lung dilatation occurred with smaller doses than constriction. 3. Histamine caused both increases and decreases in pulmonary artery pressure in collapsed lungs. In this condition these effects are unlikely to have been a consequence of changes in airway pressure. 4. From forward and reverse perfusions of lungs in the waterfall state, where changes in postalveolar vessels do not affect pulmonary artery pressure, it appeared that histamine caused both dilatation and constriction on both sides of the point of collapse caused by alveolar pressure. 5. Plots of the relationship between left atrial and pulmonary artery pressure (at constant alveolar pressure and blood flow) showed that histamine caused both increases and decreases in pulmonary vascular resistance and sometimes also increased the "Starling resistor" properties of lung vessels. 6. In plethysmograph experiments histamine caused moderate dilatation and constriction without affecting lung volume but strong vasoconstriction was accompanied by increases in lung volume.     

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.     

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.     

Functional and structural adaptation of the yak pulmonary circulation to residence at high altitude

The high-altitude (HA) native yak (Bos grunniens) has successfully adapted to chronic hypoxia (CH) despite being in the same genus as domestic cows, which are known for their great hypoxic pulmonary vasoconstrictor responses (HPVRs), muscular pulmonary arteries, and development of severe pulmonary hypertension on exposure to CH. To determine possible mechanisms by which the pulmonary circulation may adapt to CH, yak pulmonary vascular reactivity to both vasoconstrictor and vasodilator stimuli and yak pulmonary artery structure were assessed. Hypoxia caused a small but significant HPVR, and norepinephrine infusion caused a greater rise in pulmonary arterial pressure (Ppa) than did hypoxia. Acetylcholine, an endothelium-dependent vasodilator, had no effect on Ppa but lowered pulmonary resistance (Rp) by causing an increase in cardiac output. Sodium nitroprusside, an endothelium-independent vasodilator, decreased both Ppa and Rp significantly. Yak small pulmonary arteries had a 4.1 +/- 0.1% medial thickness, with vessels < or = 100 microns devoid of smooth muscle. Yak pulmonary artery endothelial cells were much longer, wider, and rounder in appearance than those of domestic cows. Thus the yak has successfully adapted to HA conditions by maintaining both a blunted HPVR and thin-walled pulmonary vessels. Differences in both endothelial cell morphology and response to acetylcholine between the yak and those reported in the domestic cow suggest the adaptation to HA may include changes not only in the amount of pulmonary vascular smooth muscle but in endothelial cell function and structure as well.     

Pulmonary veins and bronchial vessels undergo remodeling in sustained pulmonary hypertension induced by continuous air embolization into sheep

While it is well known that chronic pulmonary hypertension is accompanied by characteristic structural changes in the pulmonary arteries, it is becoming increasingly apparent that the remodeling process also involves the venous side of the circulation. The present paper utilizes a sheep model of sustained pulmonary hypertension induced by continuous air embolization (CAE) into the pulmonary arterial circulation to examine the structure of the pulmonary veins and bronchial vasculature. Morphometric techniques were applied to the pulmonary veins and bronchial vessels following distension of the venous circulation with a barium-sulfate gelatin mixture; this route of filling also resulted in distension of the bronchial vessels. Four and 12 days of CAE resulted in a significant increase in the proportion of muscular pulmonary veins (e.g., percent muscular veins < 75 microns following 12 days CAE = 17.7 +/- 6.9; controls = 0), an approximate doubling in percent venous medial thickness, and a 50% reduction in number of barium-filled peripheral vessels. Examination of the bronchial circulation revealed a striking increase in volume due both to a 50% increase in vessel diameter and a threefold increase in number of small vessels (p < .05). The authors conclude that CAE-induced chronic pulmonary hypertension is associated with remodeling of both the pulmonary veins and bronchial circulation as well as the pulmonary arteries. The mechanisms for these structural alterations are not certain, but may include local release of vasoactive and inflammatory mediators and an increase in bronchopulmonary anastomoses.     

Responses of systemic and pulmonary veins to the presence of an intravascular stent in a swine model

The outcome of stent implantation for children with pulmonary venous obstruction has been characterized by late reocclusion associated with a marked vessel neointimal proliferation. The purpose of this study was to compare the responses of the systemic vein and pulmonary vein to the presence of an intravascular stent, using a Yorkshire swine (N = 10) model. Under cardiopulmonary bypass, a single Palmaz stent was placed in the inferior vena cava (IVC) and right lower pulmonary vein (PV) with sacrifice at 4.9-6.1 months. Angiography and hemodynamic data were determined at 1 and 3 months post-stent implant and prior to euthanasia. All stents were found to be patent, with no difference in degree of thrombosis or neointimal formation. No statistical difference was found in the initial and final stent diameter for both inferior vena cava and pulmonary vein stents (PV initial 6.8 +/- 0.9; final 7.1 +/- 0.6) (IVC initial 10.4 +/- 1.2; final 10.4 +/- 1.2). Electron microscopy demonstrated smooth endothelialization of both pulmonary and systemic venous stent devices. No thrombosis was found on gross morphology. The data indicate that there is no intrinsic difference in the response of the pulmonary vein to the presence of a stent device. The clinical experience of restenosis following stent implantation for pulmonary vein stenosis appears to be more related to variables of final stent diameter combined with the marked intrinsic abnormal vessel architecture, as seen with this condition.     

Pulmonary vein stenosis after catheter ablation of atrial fibrillation

BACKGROUND: This report describes the complication of pulmonary vein stenosis with resultant severe pulmonary hypertension that developed in 2 patients after successful catheter ablation of chronic atrial fibrillation. METHODS AND RESULTS: Three months after successful catheter ablation of atrial fibrillation, both patients developed progressive dyspnea and pulmonary hypertension. Both were found to have severe stenosis of all 4 pulmonary veins near the junction with the left atrium. Balloon dilation of the stenotic pulmonary veins was performed in these patients, with improvement in dyspnea and pulmonary hypertension. CONCLUSIONS: The complication of pulmonary vein stenosis is potentially life-threatening, and the application of radiofrequency current within the pulmonary veins with standard catheter technology should be avoided. This complication can be treated with balloon dilation, although the long-term course is unknown.     

Multiple pulmonary aneurysms secondary to Hughes-Stovin syndrome: demonstration by MR angiography

We report a case of a 41-year-old patient with multiple pulmonary aneurysms secondary to Hughes-Stovin syndrome. Conventional pulmonary angiography could not be performed, because thrombus in both the inferior and superior vena cavae prevented catheter passage. Contrast-enhanced three-dimensional (3D) MR angiography (MRA) showed two segmental pulmonary aneurysms in the right lung. The affected segments of the lung were resected successfully, predicated on the MRA findings.     

Words hard to say and hard to hear: "May I give you some feedback?"

Long-term favourable effects of a treatment with both cyclosporin A and coumarin in a 35 year old Caucasian female patient with Beh?et's disease, presenting with haemoptysis caused by pulmonary thromboemboli and a single major pulmonary artery aneurysm, are reported. All disease activity and complications were well controlled during 9 years of follow-up.     

In vitro metabolism of a new 4-hydroxycoumarin anticoagulant. Structure of an unusual metabolite

A case of common atrium with anomalous systemic and pulmonary venous connections and pulmonary stenosis is described. Surgical correction was performed by pulmonary valvotomy and the insertion of an intra-atrial pericardial baffle. To our knowledge this is the first reported case of surgical correction of total anomalous connections of both systemic and pulmonary veins. The embryologic development of this condition is discussed.     

Small intestinal infusion studies in the calf

In this series of 13 patients undergoing repair of transposition of the great arteries with ventricular septal defect and pulmonary atresia, the operative risk and postoperative complications were greater than for repair of either transposition of the great arteries with ventricular septal defect and pulmonary stenosis or pulmonary arterial atresia with ventricular defect. Nevertheless, 6 of the 8 survivors improved clinically. Because operative and late mortality and morbidity rates are related to persistent right ventricular hypertension caused primarily by restricted pulmonary arterial outflow, results should be improved by performance of a preliminary systemic-pulmonary artery shunt for patients with hypoplastic pulmonary arteries and by use of the Hancock prosthesis, which has yielded lower gradients at both the proximal and distal anastomoses of the conduit. These improvements and the relief from cyanosis, exercise intolerance, and other symptoms seem to justify the continued application of surgical correction of transposition of the great arteries when associated with pulmonary atresia.     

Bilateral hydatid cyst of pulmonary arteries: MR and CT findings

The location of hydatid cysts inside pulmonary arteries has been reported only on rare occasions in the literature and is caused, in the majority of cases, by embolization due to the rupture of hydatid cysts located in the heart; more rarely, hematogenous dissemination from a hepatic focus is the cause. We report a case of a 44-year-old patient with hydatid cysts located in both the right and left pulmonary arteries, whose first clinical reference was hemoptysis. The patient had undergone surgery because of a hepatic hydatid cyst 5 months previously. The importance of this case lies in the infrequent bilateral location in both pulmonary arteries and in the absence of intracardiac hydatid cysts.     

Occlusion pressure responses in asthma and chronic obstructive pulmonary disease

During CO2 rebreathing we measured ventilation and the pressure generated during the first 0.1 sec of inspiratory effort against a closed airway (P 0.1) in 12 asthmatics during acute exacerbation, 10 normal subjects, and 10 patients with chronic obstructive pulmonary disease. In normal subjects, the ventilatory responst to CO2 correlated with the P 0.1 response measured as delta In P 0.1. Patients with chronic obstructive pulmonary disease showed depressed responses to CO2 in terms of both ventilation and deltaIn P0.1. However, P 0.1 values in the patients with chronic obstructive pulmonary disease were greater than those of the normal subjects when they were compared at an alveolar PCO2 of 60 mm Hg. Asthmatics' responses to CO2 were similar to those of patients with chronic obstructive pulmonary disease. When measured at an alveolar PCO2 of 60 mm Hg, asthmatics' P 0.1 values were greater than those of both normal subjects and patients with chronic obstructive pulmonary disease. As the asthmatics' airway obstruction decreased so did their P 0.1. The asthmatics, and to a lesser extent the patients with chronic obstructive pulmonary disease, demonstrated increased inspiratory muscle activity that could not be explained on the basis of chemical drive or alterations in functional residual capacity. In the case of the asthmatics it was possible that the increased inspiratory muscle activity was a response to airway obstruction.