Pulmonary vascular disease and operative indications in complete atrioventricular canal defect in early infancy

Pulmonary vascular disease was morphometrically analyzed in 67 patients (mean age, 19 months) with isolated complete atrioventricular canal defect. Complete obstruction of the small pulmonary arterial lumen resulting from acute fibrous proliferation and atrophy of the peripheral arterial media, which were considered absolute operative contraindications, were characteristic in six patients with Down's syndrome. Morphometric analysis of medial thickness revealed that thinning of the media of the small pulmonary arteries is generally observed at around 6 months of age in patients with complete atrioventricular canal defect and that the media in patients who have complete atrioventricular canal defect and Down's syndrome was thinner than that in such patients without Down's syndrome. These results suggest that thinning of the media as a result of two factors--Down's syndrome and aging--facilitates the rapid occurrence of fibrous intimal proliferation. Therefore intracardiac repair is desirable within 6 months of life, before medial thinning, in patients with complete atrioventricular canal defect and Down's syndrome. Excluding patients with absolute operative contraindications, the scores of the index of pulmonary vascular disease in operative survivors were below 2.0 and death occurred when scores were more than 2.2. The pulmonary vascular resistances measured in room air and by the oxygen inhalation and tolazoline tests in patients with operative contraindications were more than 7.3, 3.8, and 6.6 units.m2, respectively. We thus conclude that lung biopsy should be undertaken for patients in whom pulmonary vascular resistance is beyond these values to determine the appropriateness of surgical intervention.     

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.     

Expression of endothelin-1 in the lungs of patients with pulmonary hypertension

BACKGROUND: Pulmonary hypertension is characterized by an increase in vascular tone or an abnormal proliferation of muscle cells in the walls of small pulmonary arteries. Endothelin-1 is a potent endothelium-derived vasoconstrictor peptide with important mitogenic properties. It has therefore been suggested that endothelin-1 may contribute to increases in pulmonary arterial tone or smooth-muscle proliferation in patients with pulmonary hypertension. We studied the sites and magnitude of endothelin-1 production in the lungs of patients with various causes of pulmonary hypertension. METHODS: We studied the distribution of endothelin-1-like immunoreactivity (by immunocytochemical analysis) and endothelin-1 messenger RNA (by in situ hybridization) in lung specimens from 15 control subjects, 11 patients with plexogenic pulmonary arteriopathy (grades 4 through 6), and 17 patients with secondary pulmonary hypertension and pulmonary arteriopathy of grades 1 through 3. RESULTS: In the controls, endothelin-1-like immunoreactivity was rarely seen in vascular endothelial cells. In the patients with pulmonary hypertension, endothelin-1-like immunoreactivity was abundant, predominantly in endothelial cells of pulmonary arteries with medial thickening and intimal fibrosis. Likewise, endothelin-1 messenger RNA was increased in the patients with pulmonary hypertension and was expressed primarily at sites of endothelin-1-like immunoreactivity. There was a strong correlation between the intensity of endothelin-1-like immunoreactivity and pulmonary vascular resistance in the patients with plexogenic pulmonary arteriopathy, but not in those with secondary pulmonary hypertension. CONCLUSIONS: Pulmonary hypertension is associated with the increased expression of endothelin-1 in vascular endothelial cells, suggesting that the local production of endothelin-1 may contribute to the vascular abnormalities associated with this disorder.     

Optimal recovery of cytomegalovirus from urine as a function of specimen preparation

BACKGROUND/AIMS: Early liver transplantation is crucial in children with liver disease and pulmonary artery hypertension. Some severe pulmonary vascular anomalies associated with portal hypertension disappear after isolated liver transplantation. Evolution of pulmonary artery hypertension due to plexogenic arteriopathy is controversial, as this association is still considered a contraindication to isolated liver transplantation. Outcome of pulmonary hypertension after isolated liver transplantation is reported in three patients with portal hypertension. METHODS: After echocardiographic diagnosis, the patients had a complete hemodynamic exploration, and two had a lung biopsy. After liver transplantation, the survivors had echocardiographic follow up and a second hemodynamic exploration. RESULTS: In two children, pulmonary pressures and resistances returned to near-normal values 1 and 6 years after successful isolated liver transplantation. The third patient, with the most severe arteriopathy, had to wait 1 year for a donor, and the attempted transplantation was complicated by ventricular tachycardia; death occurred 2 days after surgery. CONCLUSIONS: Liver transplantation can reverse pulmonary artery hypertension due to high pulmonary resistances complicating liver disease with portal hypertension, provided it is carried out at an early stage. Early detection of pulmonary hypertension by systematic echocardiography may thus be crucial in these children with portal hypertension.     

CT appearance of pulmonary vasculitis in children

OBJECTIVE: The aim of this study was to determine whether a CT pattern that may represent early or subtle changes of pulmonary vasculitis in children exists. MATERIALS AND METHODS: High-resolution CT scans of the chest for 107 children were retrospectively reviewed by two radiologists who were unaware of the original study findings. Chest CT scans (conventional) for another 54 children who had symptoms or a diagnosis of vasculitis also were reviewed. RESULTS: We identified hazy or fluffy centrilobular, perivascular densities in 10 children, two of whom had small airways disease and eight of whom had vasculitis (Wegener's granulomatosis [n = 5], systemic lupus erythematosus [n = 1], scleroderma-polymyositis overlap syndrome [n = 1], and Churg-Strauss syndrome [n = 1]). The latter eight children underwent 35 scans, 17 of which were positive for these perivascular densities. All positive scans were associated with active disease of new onset (5/17) or with clinical exacerbation of preexisting systemic disease (12/17). The positive scans also were associated with an elevated erythrocyte sedimentation rate (13/17) and biopsy evidence of vasculitis from a variety of sites, including the lungs (n = 1), kidneys (n = 7), oropharynx (n = 5), skin (n = 9), lymph nodes (n = 1), and myocardium (n = 2). The single lung biopsy showed an angiocentric inflammatory-hemorrhagic process. Of the five patients who had positive scans, underwent therapy, and then had repeat studies, four patients had scans revert to normal in association with inactive disease. The remaining patient whose scan did not normalize failed to respond to treatment. CONCLUSION: The fluffy centrilobular pattern likely represents subtle changes of pulmonary vasculitis. In the appropriate clinical setting, such a finding may obviate the need for a lung biopsy.     

Delayed clearance of ICG observed in the course of hepatitis (posthepatitic ICG excretory defect) (author''s transl)

Pulmonary blood flow distribution was studied by scintillation scanning of the lungs after the infusion of iodine- 131-labeled macroaggregates of human albumin before and after the Mustard operation in 53 patients with transposition of the great arteries. The patients were classified as follows: Group I (24 infants with uncomplicated transposition of the great arteries); Group II (18 patients with transposition and ventricular septal defect); and Group III (11 patients with transposition, ventricular septal defect and pulmonary obstruction). Before operation, 21 patients had a normal distribution of pulmonary blood flow, 10 had preferential flow to the right lung and 2 had preferential flow to the left lung. After operation, 19 had a normal pattern of pulmonary blood flow, 21 had preferential flow to the right lung and 3 had preferential flow to the left lung. The scanning studies have proved helpful in follow-up of patients to rule out recurrence of the shunt, pulmonary of systemic venous obstruction, development of pulmonary hypertension and occlusion of a palliative systemic-pulmonary shunt.     

Clinical primary pulmonary hypertension: three pathologic types

Clinically, there is a group of patients with elevated pulmonary arterial pressure in whom the underlying cause is not apparent. The pulmonary arterial wedge pressure is not elevated. For such cases, the designation of primary pulmonary hypertension may be made clinically. From the clinical categorization of primary pulmonary hypertension, three distinct pathologic entities emerge, namely 1) plexogenic pulmonary arteriopathy, 2) recurrent pulmonary thromboembolism, and 3) pulmonary veno-occlusive disease. The plexogenic type is characterized initially by pulmonary arterial vasoconstriction with medial hypertrophy. Secondary proliferative intimal lesions, including the plexiform lesion, develop. Recurrent pulmonary thromboembolism is characterized by the presence of arterial thrombi of varying ages involving the microscopic-sized pulmonary arteries. Thrombi may be embolic in nature or may develop in situ. Pulmonary veno-occlusive disease is characterized by obstructive lesions of pulmonary veins and venules. The clinical presentation of the three pathologic types may be so similar that definitive diagnosis depends upon histologic examination of the lung from tissue obtained either by biopsy or at necropsy.     

Stent implantation of the arterial duct in newborns with duct-dependent circulation

AIMS: Little is known about the medium term results after stenting of the arterial duct in neonates and infants with duct-dependent cyanotic congenital heart disease. We report the results of stent implantation of the arterial duct in 21 neonates and infants. The defects for which the arterial duct was stented included pulmonary atresia with intact ventricular septum, critical pulmonary stenosis, and more complex defects with associated reduced pulmonary blood flow. METHODS AND RESULTS: Palmaz stents were used and successfully implanted in all the 21 patients. There were no major complications during the stent implantation procedure although two hospital deaths occurred 2 and 14 days after stent implantation. Cardiac catheterization was repeated electively 3 to 6 months after stent implantation. Stent stenosis due to intimal proliferation was noted in 11/13 patients who underwent recatheterization. Stenosis of the inner stent lumen ranged from 25% to 100%, mean 74%. Re-dilatation of the stent was required in five patients who were awaiting corrective surgery. In babies with pulmonary atresia or critical pulmonary stenosis, who also underwent additional balloon dilatation of the pulmonary valve, spontaneous closure of the stented arterial duct was well tolerated and when it occurred, the right ventricular size had increased and the circulation was no longer duct-dependent. In patients who required subsequent surgical corrective treatment, stenting of the duct allowed the definite corrective operation to be performed as the first surgical procedure. During the follow-up period, ranging between 2 months and 2 years, mean 8.7 months increased growth of the pulmonary arteries was seen in all the patients. No distortion of the branch pulmonary arteries was seen. CONCLUSION: In patients with cyanotic congenital heart disease stenting of the arterial duct is an effective alternative to surgical aorto-pulmonary shunts.     

Can preoperative lung function diagnosis detect risk of intraoperative pulmonary gas exchange insufficiency in artificial hip replacement with polymethylmethacrylate cement?

In a study of 90 patients in whom a hipjoint had been replaced for the first time using polymethylmetacrylate cement, the extent of intraoperative pulmonary gas exchange disorders was established. The effect of a preexisting disorder of lung function was determined. We checked whether an appraisal of the risk patients who are operated on can be assisted by a preoperative analysis of lung function. After preoperative diagnosis of lung function, the arterial blood gases were analysed at defined times during the operation. An intraoperative fall in the partial pressure of oxygen and an increase in carbon dioxide partial pressure in the arterial blood were found in all patients. There were pronounced interindividual differences in the extent of the disorder of pulmonary gas exchange. The degree of severity of the respective acute disorder of lung function did not show any correlation with the pre-existing disorder of pulmonary ventilation. Major hemodynamic changes were not observed. According to the present findings, a definitive statement with regard to the degree of severity of intraoperatively occurring disorders of pulmonary function cannot be expected from a preoperative analysis of pulmonary function.     

High-resolution CT of the chest in four patients with pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease

OBJECTIVE: Clinical differentiation of isolated pulmonary hypertensive arteriopathy from pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease can be difficult on a clinical basis alone. Differentiation is important because misdiagnosis of pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease may lead to severe vasodilator-induced pulmonary edema. The objective of our study was to determine whether high-resolution CT of the chest could distinguish pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease from isolated pulmonary hypertensive arteriopathy. CONCLUSION: Pulmonary hypertension in patients who also have pulmonary capillary hemangiomatosis or pulmonary venoocclusive disease shows characteristics on high-resolution CT that are not seen in patients with isolated pulmonary hypertensive arteriopathy.     

Predictors of mortality in pulmonary thromboendarterectomy

BACKGROUND: The operative mortality associated with surgical thromboendarterectomy of the pulmonary arteries has decreased at the University of California in San Diego with the application of new techniques. For universal performance of the procedure, however, those factors that contribute to the high operative mortality must be identified. We analyzed our results in 34 consecutive patients undergoing pulmonary thromboendarterectomy to determine those preoperative factors that contribute to operative mortality. METHODS: Since 1983, 34 patients with severe, surgically correctable chronic thromboembolic pulmonary hypertension who were judged to be operable by pulmonary arteriography underwent pulmonary thromboendarterectomy. No patient was excluded because of right ventricular failure or hemodynamic severity of disease; the mean pulmonary artery pressure (PAP) was 54 mm Hg, the mean pulmonary vascular resistance (PVR) was 1,094 dynes.s.cm-5, and all patients were in New York Heart Association functional class III or IV. RESULTS: Postoperative course was characterized either by swift recovery (mean length of stay, 13 days) or by rapid demise resulting from pulmonary or right ventricular failure, or both (overall operative mortality, 23%). In survivors, the mean PAP, PVR, cardiac output, and New York Heart Association functional class were significantly improved (p < 0.05). Patients who died had a significantly greater mean preoperative PAP than did those who survived (62.1 +/- 1.2 versus 49.5 +/- 2.3 mm Hg; p < 0.01) and significantly higher PVR (1,512 +/- 116 versus 949 +/- 85 dynes.s.cm-5; p < 0.01). In addition, both a PVR of more than 1,100 dynes.s.cm-5 and a mean PAP of more than 50 mm Hg could accurately predict operative mortality: operative mortality was six times greater in patients with a preoperative PVR of greater than 1,100 dynes.s.cm-5 (41% versus 5.85%) and almost five times greater in those with a mean PAP of greater than 50 mm Hg (37% versus 8%). No intraoperative factors, including the use or duration of circulatory arrest, affected outcome. CONCLUSIONS: Patients with severe hemodynamic disease (PVR > 1,100 dynes.s.cm-5 and PAP > 50 mm Hg) have a high likelihood of operative mortality and perhaps should not undergo pulmonary thromboendarterectomy, except at institutions where the operation is performed frequently.     

Determinants of successful balloon valvotomy in infants with critical pulmonary stenosis or membranous pulmonary atresia with intact ventricular septum

OBJECTIVES: This study reviewed our experience with percutaneous balloon valvotomy in infants with critical pulmonary stenosis or membranous pulmonary atresia with intact ventricular septum and defined the anatomic and hemodynamic characteristics of infants in whom this procedure is successful and provides definitive therapy. BACKGROUND: Unlike children with valvular pulmonary stenosis, the follow-up of infants with critical pulmonary stenosis undergoing percutaneous balloon valvotomy is limited. METHODS: Between December 1987 and August 1992, percutaneous balloon valvotomy was attempted in 12 infants with critical pulmonary stenosis (n = 10) or pulmonary atresia with intact ventricular septum (n = 2). Two outcome groups were identified: Group A patients are acyanotic, have mild residual pulmonary stenosis and have not required operation; Group B patients have required operation. RESULTS: Of the 12 infants, 11 had a successful balloon valvotomy procedure. Group A patients (n = 7) have a residual gradient of 22 +/- 18.7 mm Hg (mean +/- SD) at follow-up of 3.2 years (range 1.2 to 5.0). In Group B (n = 5), operation was required for inability to cross the pulmonary valve (n = 1) or persistent severe hypoxemia for > or = 2 weeks after valvotomy (n = 4). Significant differences (p < or = 0.01) between the two groups (Group A vs. Group B) were identified in pulmonary valve annulus (Z value) 8.1 mm (-1.1) versus 5.5 mm (-3.4); tricuspid valve annulus (Z value) 14.0 mm (0.8) versus 8.8 mm (-1.8); right ventricular volume 65 versus 29 ml/m2; and Lewis index 10.9 versus 8.9. CONCLUSIONS: Percutaneous balloon valvotomy is effective and likely to provide definitive therapy in infants with critical pulmonary stenosis or membranous pulmonary atresia with intact ventricular septum who have a tricuspid valve annulus > 11 mm, pulmonary valve annulus > or = 7 mm and right ventricular volume > 30 ml/m2.     

Hydrogen peroxide gas plasma sterilization is effective against Cryptosporidium parvum oocysts

Moyamoya disease is an occlusive intracranial arteriopathy with abnormal cerebral vascular collateral networks. Although this disease is known to be associated with stenosis of extracranial arteries, such as the renal artery, a case associated with stenoses of the coronary and renal arteries has not been reported. We described here a 23-year-old man who had effort angina, renovascular hypertension, and asymptomatic moyamoya disease. Arterioangiography revealed bilateral occlusion of the intracranial carotid arteries and stenoses in the left coronary artery and the left renal artery.     

The role of endothelial nitric oxide synthase expression in the development of pulmonary hypertension in chronically hypoxic infant swine

OBJECTIVE: Our goal was to determine the role of pulmonary endothelial nitric oxide synthase expression in the development of pulmonary hypertension in infants with congenital cyanotic heart disease. METHODS: Two groups of 4-week-old piglets were studied. In one group, the piglets were raised in an environment of 10% oxygen from 2 days of age (cyanotic, n = 6), and in the other group the piglets were raised at room air (control, n = 5). Pulmonary hemodynamics were measured in vivo for each animal, and peripheral lung biopsy specimens were obtained for Western blot analysis with the use of antiendothelial nitric oxide synthase antibody and for activity analysis with the use of the tritiated L-arginine assay. RESULTS: The piglets in the chronically hypoxic group had significant increases in mean pulmonary arterial pressure (44.0 +/- 3.8 mm Hg vs 14.8 +/- 1.2 mm Hg in controls, p = 0.0007) and pulmonary vascular resistance (7272.0 +/- 871.1 dyne x cm x sec(-5) vs 1844.5 +/- 271.2 dyne x cm x sec(-5) in controls, p = 0.002). These changes in the pulmonary hemodynamics of the hypoxic piglets were accompanied by a twofold increase in the expression of pulmonary endothelial nitric oxide synthase (p = 0.0043) but no corresponding increase in nitric oxide synthase activity. CONCLUSIONS: Raising infant piglets in an environment of 10% oxygen for 4 weeks results in significant pulmonary arterial hypertension accompanied by increased expression of nitric oxide synthase within the lung endothelium. Furthermore, the increased levels of nitric oxide synthase within the lungs of the hypoxic swine were not accompanied by a proportional increase in enzyme activity. These findings suggest that the development of pulmonary hypertension in infants with congenital cyanotic disease is not due to decreased expression of endothelial nitric oxide synthase, but instead may be related to a decreased ability of the enzyme to produce sufficient nitric oxide.     

Thrombotic lesions in primary plexogenic arteriopathy. Similar pathogenesis or complication?

In 78 patients with primary plexogenic arteriopathy (PPA), numbers of organized and recanalized thrombi were established in histologic slides of lung tissue and expressed per square centimeter of section. Three control groups of ten individuals each were used: normal, plexogenic arteriopathy secondary to ventricular septal defect, and hypoxic pulmonary hypertension. Thrombotic lesions were scarce in normal individuals but numerous in all three groups with pulmonary hypertension. There is also a positive correlation with age. Thrombotic lesions are absent or scarce in children but more common in adults, even in normal control subjects and particularly in pulmonary hypertension by whatever cause. In PPA there is likely to be a relation with the duration of illness but not with the stage of the disease. The complete pattern of plexogenic arteriopathy may develop in the absence of thrombotic lesions, which clearly are not essential for its pathogenesis. Rather than being part specifically of PPA, as sometimes suggested, thrombotic lesions complicate various types of hypertensive pulmonary vascular disease. Apparently the combination of sustained pulmonary hypertension and age, possibly through endothelial injury, may elicit thrombosis and its sequelae, which in turn may aggravate the pulmonary arterial pressure.     

Is vertical vein ligation necessary in repair of total anomalous pulmonary venous connection?

BACKGROUND: In the repair of total anomalous venous connection, vertical vein ligation is recommended to eliminate left-to-right shunting. However, the small left heart chambers may not always tolerate the immediate increase in blood flow after combined repair and vein ligation. METHODS: A retrospective review of 23 infants and children undergoing correction of total anomalous pulmonary venous connection was undertaken to determine whether vertical vein ligation is a necessary component of successful surgical repair. In 14 patients this vein was ligated, whereas in 9 it was left patent. Six patients who underwent ligation and 5 who did not had pulmonary venous obstruction before operation. RESULTS: The operative mortality rate was 36% (5 of 14 patients) for the ligated group compared with 0% (0 of 9 patients) for the nonligated group (p = 0.06). All deaths occurred in patients with preoperative obstruction and a low mean left atrial pressure, and four of the deaths were directly attributable to left heart failure. Follow-up echocardiography in patients in whom the vertical vein was not ligated revealed adequate cardiac function and no residual left-to-right flow through the previously patent venous conduit. CONCLUSION: Vertical vein ligation during the repair of total anomalous pulmonary venous connection is not routinely necessary and actually may be undesirable in patients with preoperative obstruction, in whom the left heart chambers are particularly small.     

Neonates with congenital heart disease, Part IV: Total anomalous pulmonary venous return

Significant radiographic findings of TAPVR with unobstructed blood flow include the following: 1. Increased pulmonary vascular markings with dilated pulmonary arteries 2. Cardiomegaly 3. A "snowman" configuration of the heart, seen after pulmonary vascular resistance falls and blood flow through the lungs increases In TAPVR with obstructed blood flow, findings include the following: 1. A hazy, reticular, ground-glass appearance of the lung fields 2. Normal to small cardiac size.     

Thoracoscopic lung biopsy or open lung biopsy for interstitial lung disease

Both traditional open lung biopsy through a limited thoracotomy and VATS lung biopsy are effective methods for obtaining parenchymal samples in patients who have respiratory insufficiency and radiographic pulmonary infiltrates. For patients with slowly progressive disease processes, who require an elective biopsy, VATS biopsy is the procedure of choice because of the ability to visualize and sample multiple areas of the lung, and because of the decreased postoperative pain. On the other hand, when patients are critically ill and already on high-level ventilatory support, the VATS method offers no advantages over the standard minimal thoracotomy.     

Prevalence of acute pulmonary embolism in central and subsegmental pulmonary arteries and relation to probability interpretation of ventilation/perfusion lung scans

PURPOSE: The purpose of this investigation is to determine the prevalence of acute pulmonary embolism (PE) limited to subsegmental pulmonary arteries. BACKGROUND: Contrast-enhanced helical (spiral) and electron-beam CT, in the hands of experienced radiologists who are skillful with this modality, are sensitive for the detection of acute PE in central pulmonary arteries, but have a low sensitivity for the detection of PE limited to subsegmental pulmonary arteries. The potential for CT to diagnose PE, therefore, is partially dependent on the prevalence of PE limited to subsegmental pulmonary arteries. METHODS: Data are from the Prospective Investigation of Pulmonary Embolism Diagnosis (PIOPED). The largest pulmonary arteries that showed PE, as interpreted by the PIOPED angiographic readers, were identified in 375 patients in PIOPED with angiographically diagnosed PE. RESULTS: Among all patients with PE, 6% (95% confidence interval [CI], 4 to 9%) had PE limited to subsegmental branches of the pulmonary artery. Patients with high-probability ventilation/ perfusion (V/Q) scans had PE limited to subsegmental branches in only 1% (95% CI, 0 to 4%). Among patients with low-probability V/Q lung scans, 17% (95% CI, 8 to 29%) had PE limited to the subsegmental branches. Patients with low-probability V/Q scans and no prior cardiopulmonary disease had PE limited to the subsegmental pulmonary arteries in 30% (95% CI, 13 to 53%), whereas patients with low-probability V/Q scans who had prior cardiopulmonary disease had PE limited to subsegmental pulmonary arteries in 8% (95% CI, 2 to 22%) (p < 0.05). CONCLUSION: Based on data from all patients with PE in PIOPED, the prevalence of PE limited to subsegmental pulmonary arteries is low, 6%. PE limited to subsegmental pulmonary arteries was most prevalent among patients with low-probability V/Q scans, particularly if they had no prior cardiopulmonary disease.     

Segmental contour pattern in a case of pulmonary venoocclusive disease

A V/Q mismatch (segmental contour pattern) is described in a patient suffering from dyspnea. Chest roentgenography revealed a mild interstitial pattern and enlarged pulmonary arteries. A lung biopsy demonstrated pulmonary venoocclusive disease.