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Rings, Slings, and Other Things: Vascular Compression of the Infant Trachea Updated from the Midcentury to the Millennium-The Legacy of Robert E. Gross, MD, and Edward B. D. Neuhauser, MD¹

¹ From the Department of Radiology, Babies & Children’s Hospital of New York, 3959 Broadway, BHN 3-318, New York, NY 10032. Received August 9, 1999; revision requested September 14; final revision received March 7, 2000; accepted March 24. Address correspondence to the author (e-mail: berdonw@cpmc3.cpmc.columbia.edu).

ABSTRACT

In the first half of the 20th century, pediatric chest imaging was limited mainly to the performance of conventional radiography, including barium esophagography and occasionally bronchography and angiography. Despite this limited imaging approach, by 1950 the diagnosis and treatment of vascular "rings" compressing infant airways had been accomplished with the pioneering efforts of Robert E. Gross, MD, in the field of surgery, and Edward B. D. Neuhauser, MD, in the field of radiology. The next two decades brought the recognition of pulmonary arterial "sling," or anomalous left pulmonary artery, in diagnosis and treatment. Recognition of still another vascular compressive syndrome in infants was identified as that due to the absence of the pulmonary valve. These "rings, slings, and other things" are now evaluated with magnetic resonance (MR) imaging, including MR angiography, and computed tomography (CT), including CT angiography, with the added use of three-dimensional reconstruction. These are the legacies of Drs Gross and Neuhauser.

Index terms: Computed tomography (CT), in infants and children, 50.1215, 60.1211 • Infants, cardiovascular system, 50.14 • Infants, respiratory system, 50.14, 60.14 • Magnetic resonance (MR), in infants and children, 50.1214, 60.1214 • Reflections • Respiratory distress syndrome, in infants and children, 60.781

Dr Proto asked me to take an area of my interest in the past and describe how we did it then versus how we do it now. I chose to revisit the topic addressed in "Vascular Anomalies of the Infant Lung: Rings, Slings and Other Things," an article on a group of congenital vascular anomalies that affected infant breathing that was written by David Baker, MD, and me and published in Seminars in Roentgenology in 1972 (1). The editor of the journal, Benjamin Felson, MD, provided the pithy title, " ... Rings, Slings and Other Things," and the article was well received.

In the following presentation, I will review how these anomalies were first recognized and operated on more than 50 years ago, starting with the historic contributions of Gross (2) and Neuhauser (3) from Children’s Hospital Boston (Fig 1). I have attempted to provide historical illustrations—artistic as well as radiologic—to illustrate the work-up through the 1980s and 1990s (4) as magnetic resonance (MR) imaging and computed tomography (CT) emerged, and then finally address the millennium with the use of highly sophisticated three-dimensional CT and MR images of good detail.

View larger version (124K): [in this window] [in a new window] [Download PPT slide]   Figure 1. Photograph of the physicians who were active at Children’s Hospital Boston, obtained in 1950. Front row, left to right: F. Ingraham, MD, neurosurgery; S. Farber, MD, pathology; and W. Green, MD, orthopedics. Back row, left to right: C. Janeway, MD, pediatrics; G. Brugler, hospital director; Edward B. D. Neuhauser, MD, pediatric radiology; and R. Gross, MD, pediatric surgery. (Photograph courtesy of N. Thorne Griscom, MD, Children’s Hospital Boston, Mass.)

Patients with any of these diseases may present with respiratory distress, feeding problems, or stridor, and, thus, it is essential to carefully pick added studies. We cannot throw out the old studies that were so helpful to prior generations, even if there are newer approaches to spiral CT and MR imaging.

As an aside, Dr Proto asked the contributors to describe the radiologic department of the last 4 decades. That is easy: Babies & Children’s Hospital of New York had two x-ray film rooms, and one had mirror image intensification. There was no Medline and no wide body of knowledge on vascular rings beyond the data in the articles of Gross and Neuhauser, which were more than 25 years old (2,3). A chart on the value of the barium esophagram in such patients on the reading room wall got us started. The chart, from a European x-ray film company, was based on the work of A. C. Klinkhamer, MD, of Amsterdam, the Netherlands (5). He had described 20 patterns with vascular-induced esophageal indentations. All Dr Baker and I did was simplify these 20 patterns into four patterns (1,4): (a) anterior tracheal, posterior esophageal indentation—that is, vascular ring; (b) normal trachea, posterior esophageal indentation—that is, aberrant subclavian artery; (c) posterior tracheal, anterior esophageal indentation—that is, pulmonary sling; and (d) anterior tracheal indentation, normal esophagram—that is, innominate arterial compression.

It was simple (actually too simple) and easy to remember, and it caught on. When the "rings ... slings" article was published, we had not included the anomaly of absent pulmonary valve.

TRACHEAL NARROWING: IS IT COMPRESSION OR STENOSIS?

The soft trachea of the infant may be compressed by a variety of vascular anomalies, and these should be kept in mind when viewing images of children with respiratory distress or stridor. Conventional radiographic techniques should not be limited to the acquisition of the low-kilovoltage conventional radiographs that are so commonly obtained in small children. On such radiographs, the airway is hard to see on anteroposterior views owing to the excessive absorption of soft x rays in bone, and lateral radiographs may be less than optimal, if they are obtained at all. Frontal and lateral high-kilovoltage filtered radiographs are easily obtained and advantageously show the entire airway. We still use these studies plus barium esophagography; these usually allow a correct diagnosis to be made. One can then proceed to CT or MR imaging. If necessary, electron-beam or spiral CT can be very useful in evaluating dynamic changes of the airway. MR imaging is valuable in demonstrating the relation of the airway to adjacent blood vessels without injection of intravascular contrast media. Both CT and MR imaging can provide three-dimensional reconstruction; and CT angiography and MR angiography may prove to be helpful.

RINGS

Vascular Rings Compressing the Trachea with Posterior Esophageal Indentation
It is fascinating to read the following paragraph by Dr Gross from his first report of successful repair of a vascular ring (2):

In 1931, I performed an autopsy on a five-month old baby who had wheezing respiration since birth. At this examination a ring of blood vessels was found encircling the intrathoracic portion of the esophagus and trachea in such a way that the esophagus was indented from behind whereas the trachea was compressed on its anterior surface. The pathological findings suggested that a division of some part of the so called "vascular ring" during life probably would have relieved the pressure on the constricted esophagus and trachea.

By the 1950s, Dr Gross had made repairs in more than 50 such cases! Vascular rings remain the most important vascular cause of tracheal obstruction. The vascular ring is usually one of two types—a double aortic arch (Fig 2) or a variant right aortic arch with an aberrant left subclavian artery and a ductal remnant completing the ring. There is anterior tracheal compression and a prominent posterior esophageal indentation, which are seen best on lateral views (Fig 3) (4). The defects are below the sternal notch, above the carina, and usually not associated with aeration disturbances of the lung. CT (electron beam or spiral) (Fig 4a–4d) and MR imaging (Fig 5a, 5b) have been useful in delineating the vascular anatomy in multiple planes and have made angiography superfluous (6,7).

View larger version (89K): [in this window] [in a new window] [Download PPT slide]   Figure 2. Diagram of a typical double aortic arch vascular ring. The ductus arteriosus (DA) is the ductal remnant, which also must be divided. The right posterior arch may be dominant. In some patients, the left anterior arch is dominant. Ao = aorta, LC = left common carotid artery, LS = left subclavian artery, O = esophagus, PA = main pulmonary artery, RC = right common carotid artery, RS = right subclavian artery, T = trachea. (Reprinted, with permission, from reference 5.)

View larger version (68K): [in this window] [in a new window] [Download PPT slide]   Figure 3. Imaging in the late 1950s. A, Lateral barium esophagram shows posterior indentation in the esophagus. B, Left ventricular angiogram shows a dominant right arch (arrow) and smaller left arch. The catheter was passed from the inferior vena cava through the foramen ovale into the left atrium and then into the left ventricle. (Photographs courtesy of John Kirkpatrick, MD, St Christopher’s Hospital, Philadelphia, Pa.)

View larger version (83K): [in this window] [in a new window] [Download PPT slide]   Figure 4a. (a, b) Electron-beam CT images of a double aortic arch. (a) The dominant right arch (arrow) and smaller left arch (arrowhead) are diagnostic of a double aortic arch vascular ring. (b) Image obtained slightly inferior to a shows the uniting descending aortas (arrow) slightly to the left of the midline. (Images courtesy of J. Kuhn, MD, Buffalo Children’s Hospital, New York.) (c-e) Three-dimensional spiral CT reconstructions of a double aortic arch with a dominant right arch. (c) Anterior and (d) posterior views, and (e) view from above are shown. (Images courtesy of Ronald Cohen, MD, Children’s Hospital, Oakland, Calif.)

View larger version (93K): [in this window] [in a new window] [Download PPT slide]   Figure 4b. (a, b) Electron-beam CT images of a double aortic arch. (a) The dominant right arch (arrow) and smaller left arch (arrowhead) are diagnostic of a double aortic arch vascular ring. (b) Image obtained slightly inferior to a shows the uniting descending aortas (arrow) slightly to the left of the midline. (Images courtesy of J. Kuhn, MD, Buffalo Children’s Hospital, New York.) (c-e) Three-dimensional spiral CT reconstructions of a double aortic arch with a dominant right arch. (c) Anterior and (d) posterior views, and (e) view from above are shown. (Images courtesy of Ronald Cohen, MD, Children’s Hospital, Oakland, Calif.)

View larger version (68K): [in this window] [in a new window] [Download PPT slide]   Figure 4c. (a, b) Electron-beam CT images of a double aortic arch. (a) The dominant right arch (arrow) and smaller left arch (arrowhead) are diagnostic of a double aortic arch vascular ring. (b) Image obtained slightly inferior to a shows the uniting descending aortas (arrow) slightly to the left of the midline. (Images courtesy of J. Kuhn, MD, Buffalo Children’s Hospital, New York.) (c-e) Three-dimensional spiral CT reconstructions of a double aortic arch with a dominant right arch. (c) Anterior and (d) posterior views, and (e) view from above are shown. (Images courtesy of Ronald Cohen, MD, Children’s Hospital, Oakland, Calif.)

View larger version (83K): [in this window] [in a new window] [Download PPT slide]   Figure 4d. (a, b) Electron-beam CT images of a double aortic arch. (a) The dominant right arch (arrow) and smaller left arch (arrowhead) are diagnostic of a double aortic arch vascular ring. (b) Image obtained slightly inferior to a shows the uniting descending aortas (arrow) slightly to the left of the midline. (Images courtesy of J. Kuhn, MD, Buffalo Children’s Hospital, New York.) (c-e) Three-dimensional spiral CT reconstructions of a double aortic arch with a dominant right arch. (c) Anterior and (d) posterior views, and (e) view from above are shown. (Images courtesy of Ronald Cohen, MD, Children’s Hospital, Oakland, Calif.)

View larger version (71K): [in this window] [in a new window] [Download PPT slide]   Figure 4e. (a, b) Electron-beam CT images of a double aortic arch. (a) The dominant right arch (arrow) and smaller left arch (arrowhead) are diagnostic of a double aortic arch vascular ring. (b) Image obtained slightly inferior to a shows the uniting descending aortas (arrow) slightly to the left of the midline. (Images courtesy of J. Kuhn, MD, Buffalo Children’s Hospital, New York.) (c-e) Three-dimensional spiral CT reconstructions of a double aortic arch with a dominant right arch. (c) Anterior and (d) posterior views, and (e) view from above are shown. (Images courtesy of Ronald Cohen, MD, Children’s Hospital, Oakland, Calif.)

View larger version (139K): [in this window] [in a new window] [Download PPT slide]   Figure 5a. MR imaging in the late 1980s. (a, b) T1-weighted spin-echo images (repetition time msec/echo time msec, 500/30) of a double aortic arch. (a) Posterior coronal image shows two arches meeting to form the descending aorta; the left arch is slightly bigger. (b) The more anterior image shows the two aortic arches on either side of the trachea, which is slightly narrowed. (c) Anterior and (d) posterior T1-weighted, spin-echo, three-dimensional MR reconstructions (750/30) of the double aortic arch in a and b. In c and d, AAo = ascending aorta, DA = descending aorta, DAo = descending aorta, ES = esophagus (yellow), LAA = left aortic arch, LCCA = left common carotid artery, LSA = left subclavian artery, RAA = right aortic arch, RCCA = right common carotid artery, RSA = right subclavian artery, TR = trachea (white). (Images in c and d courtesy of Beverley Newman, MD, Children’s Hospital, Pittsburgh, Pa.)

View larger version (131K): [in this window] [in a new window] [Download PPT slide]   Figure 5b. MR imaging in the late 1980s. (a, b) T1-weighted spin-echo images (repetition time msec/echo time msec, 500/30) of a double aortic arch. (a) Posterior coronal image shows two arches meeting to form the descending aorta; the left arch is slightly bigger. (b) The more anterior image shows the two aortic arches on either side of the trachea, which is slightly narrowed. (c) Anterior and (d) posterior T1-weighted, spin-echo, three-dimensional MR reconstructions (750/30) of the double aortic arch in a and b. In c and d, AAo = ascending aorta, DA = descending aorta, DAo = descending aorta, ES = esophagus (yellow), LAA = left aortic arch, LCCA = left common carotid artery, LSA = left subclavian artery, RAA = right aortic arch, RCCA = right common carotid artery, RSA = right subclavian artery, TR = trachea (white). (Images in c and d courtesy of Beverley Newman, MD, Children’s Hospital, Pittsburgh, Pa.)

View larger version (121K): [in this window] [in a new window] [Download PPT slide]   Figure 5c. MR imaging in the late 1980s. (a, b) T1-weighted spin-echo images (repetition time msec/echo time msec, 500/30) of a double aortic arch. (a) Posterior coronal image shows two arches meeting to form the descending aorta; the left arch is slightly bigger. (b) The more anterior image shows the two aortic arches on either side of the trachea, which is slightly narrowed. (c) Anterior and (d) posterior T1-weighted, spin-echo, three-dimensional MR reconstructions (750/30) of the double aortic arch in a and b. In c and d, AAo = ascending aorta, DA = descending aorta, DAo = descending aorta, ES = esophagus (yellow), LAA = left aortic arch, LCCA = left common carotid artery, LSA = left subclavian artery, RAA = right aortic arch, RCCA = right common carotid artery, RSA = right subclavian artery, TR = trachea (white). (Images in c and d courtesy of Beverley Newman, MD, Children’s Hospital, Pittsburgh, Pa.)

View larger version (113K): [in this window] [in a new window] [Download PPT slide]   Figure 5d. MR imaging in the late 1980s. (a, b) T1-weighted spin-echo images (repetition time msec/echo time msec, 500/30) of a double aortic arch. (a) Posterior coronal image shows two arches meeting to form the descending aorta; the left arch is slightly bigger. (b) The more anterior image shows the two aortic arches on either side of the trachea, which is slightly narrowed. (c) Anterior and (d) posterior T1-weighted, spin-echo, three-dimensional MR reconstructions (750/30) of the double aortic arch in a and b. In c and d, AAo = ascending aorta, DA = descending aorta, DAo = descending aorta, ES = esophagus (yellow), LAA = left aortic arch, LCCA = left common carotid artery, LSA = left subclavian artery, RAA = right aortic arch, RCCA = right common carotid artery, RSA = right subclavian artery, TR = trachea (white). (Images in c and d courtesy of Beverley Newman, MD, Children’s Hospital, Pittsburgh, Pa.)

Anterior Compression of the Trachea with Normal Esophagus: Innominate Arterial Compression or Tracheomalacia?
The conventional radiographs obtained in some infants with stridor show an anterior compression of the trachea, and the barium esophagogram is normal (Fig 6a, 6b) (8). Gross called this an anomalous innominate artery with the assumption that the innominate artery arose in front of rather than to the right of the trachea, or as a common origin with the left carotid artery (bitruncus) with tracheal compression. The relationships of these vessels to the airway are variable and virtually indistinguishable among those with and those without symptoms. Recent work suggests that the symptoms are primarily a reflection of an excessively lax pars membranacea in the posterior wall of the trachea (ie, tracheomalacia) (Fig 6c) (9,10). These findings have been noted especially in survivors of esophageal atresia with tracheoesophageal fistula.

View larger version (92K): [in this window] [in a new window] [Download PPT slide]   Figure 6a. (a) Anteroposterior view of necropsy specimen shows tracheal indentation (arrow) by innominate artery. The infant died of unrelated causes. (Photograph courtesy of W. Blanc, MD, Babies & Children’s Hospital of New York.) (b) Sagittal (left) and coronal (right) T1-weighted MR images (750/30). Left: The innominate artery (a) is anterior to and indenting the trachea (t). The vein (v) and thymus (th) are noted. Note the cervical extension of the thymus. Right: The innominate artery (arrows) passes in front and to the right of the trachea (t). (Images courtesy of G. Mandell, MD, DuPont Institute, Wilmington, Del.) (c) Tracheomalacia, or innominate artery syndrome. Histologic section of the midthoracic esophagus (E) and trachea (T) obtained at autopsy shows the tracheal cartilage is reduced in length and the membranous trachea is increased. The overall tracheal lumen is flattened. (Hematoxylin-eosin stain; original magnification, x30.) (Photograph of specimen courtesy of J. L. Emery, MD, Sheffield, England.) (d) Electron-beam CT images of tracheomalacia, or innominate artery syndrome. The same image level is noted to change the tracheal caliber from narrowed to normal during the respiratory cycle. The trachea is outlined in white. A = innominate artery. (Images courtesy of Wilbur Smith, MD, University of Iowa Hospitals & Clinics, Iowa City, Iowa.)

View larger version (89K): [in this window] [in a new window] [Download PPT slide]   Figure 6b. (a) Anteroposterior view of necropsy specimen shows tracheal indentation (arrow) by innominate artery. The infant died of unrelated causes. (Photograph courtesy of W. Blanc, MD, Babies & Children’s Hospital of New York.) (b) Sagittal (left) and coronal (right) T1-weighted MR images (750/30). Left: The innominate artery (a) is anterior to and indenting the trachea (t). The vein (v) and thymus (th) are noted. Note the cervical extension of the thymus. Right: The innominate artery (arrows) passes in front and to the right of the trachea (t). (Images courtesy of G. Mandell, MD, DuPont Institute, Wilmington, Del.) (c) Tracheomalacia, or innominate artery syndrome. Histologic section of the midthoracic esophagus (E) and trachea (T) obtained at autopsy shows the tracheal cartilage is reduced in length and the membranous trachea is increased. The overall tracheal lumen is flattened. (Hematoxylin-eosin stain; original magnification, x30.) (Photograph of specimen courtesy of J. L. Emery, MD, Sheffield, England.) (d) Electron-beam CT images of tracheomalacia, or innominate artery syndrome. The same image level is noted to change the tracheal caliber from narrowed to normal during the respiratory cycle. The trachea is outlined in white. A = innominate artery. (Images courtesy of Wilbur Smith, MD, University of Iowa Hospitals & Clinics, Iowa City, Iowa.)

View larger version (141K): [in this window] [in a new window] [Download PPT slide]   Figure 6c. (a) Anteroposterior view of necropsy specimen shows tracheal indentation (arrow) by innominate artery. The infant died of unrelated causes. (Photograph courtesy of W. Blanc, MD, Babies & Children’s Hospital of New York.) (b) Sagittal (left) and coronal (right) T1-weighted MR images (750/30). Left: The innominate artery (a) is anterior to and indenting the trachea (t). The vein (v) and thymus (th) are noted. Note the cervical extension of the thymus. Right: The innominate artery (arrows) passes in front and to the right of the trachea (t). (Images courtesy of G. Mandell, MD, DuPont Institute, Wilmington, Del.) (c) Tracheomalacia, or innominate artery syndrome. Histologic section of the midthoracic esophagus (E) and trachea (T) obtained at autopsy shows the tracheal cartilage is reduced in length and the membranous trachea is increased. The overall tracheal lumen is flattened. (Hematoxylin-eosin stain; original magnification, x30.) (Photograph of specimen courtesy of J. L. Emery, MD, Sheffield, England.) (d) Electron-beam CT images of tracheomalacia, or innominate artery syndrome. The same image level is noted to change the tracheal caliber from narrowed to normal during the respiratory cycle. The trachea is outlined in white. A = innominate artery. (Images courtesy of Wilbur Smith, MD, University of Iowa Hospitals & Clinics, Iowa City, Iowa.)

View larger version (62K): [in this window] [in a new window] [Download PPT slide]   Figure 6d. (a) Anteroposterior view of necropsy specimen shows tracheal indentation (arrow) by innominate artery. The infant died of unrelated causes. (Photograph courtesy of W. Blanc, MD, Babies & Children’s Hospital of New York.) (b) Sagittal (left) and coronal (right) T1-weighted MR images (750/30). Left: The innominate artery (a) is anterior to and indenting the trachea (t). The vein (v) and thymus (th) are noted. Note the cervical extension of the thymus. Right: The innominate artery (arrows) passes in front and to the right of the trachea (t). (Images courtesy of G. Mandell, MD, DuPont Institute, Wilmington, Del.) (c) Tracheomalacia, or innominate artery syndrome. Histologic section of the midthoracic esophagus (E) and trachea (T) obtained at autopsy shows the tracheal cartilage is reduced in length and the membranous trachea is increased. The overall tracheal lumen is flattened. (Hematoxylin-eosin stain; original magnification, x30.) (Photograph of specimen courtesy of J. L. Emery, MD, Sheffield, England.) (d) Electron-beam CT images of tracheomalacia, or innominate artery syndrome. The same image level is noted to change the tracheal caliber from narrowed to normal during the respiratory cycle. The trachea is outlined in white. A = innominate artery. (Images courtesy of Wilbur Smith, MD, University of Iowa Hospitals & Clinics, Iowa City, Iowa.)

SLINGS

Pulmonary Sling: Anomalous Left Pulmonary Artery with Tracheal Displacement Anteriorly and Anterior Esophageal Indentation
"Pulmonary sling" is the term commonly used to describe an anomalous or aberrant left pulmonary artery (Fig 7a, 7b) (11). In most cases, the barium esophagram characteristically shows a mass between the trachea and the esophagus, just above the level of the carina. The term "sling" (11) is best used when the proximal portion of the anomalous vessel impinges on the right main bronchus and causes obstructive emphysema (Fig 7c) of the entire right lung or the right middle and lower lobes, depending on the site of the compression. Conventional radiographs obtained in neonates at birth may show fetal fluid retention or air, with a mediastinal shift usually to the left side. Repositioning of the artery usually cures this compression, because the underlying tracheobronchial tree is basically normal.

View larger version (66K): [in this window] [in a new window] [Download PPT slide]   Figure 7a. (a) Diagram of anomalous left pulmonary artery, or pulmonary sling. Br. = bronchus, L.A. = ligamentous remnant of ductus arteriosus, L.L.L. = left lower lobe, L.P.A. = left pulmonary artery (in anomalous retrotracheal course), L.U.L. = left upper lobe, P.T. = pulmonary trunk, R.L.L. = right lower lobe, R.M.L. = right middle lobe, R.P.A. = right pulmonary artery, R.U.L. = right upper lobe. (Reprinted, with permission, from reference 18.) (b) Lateral airway esophagrams show an anomalous left pulmonary artery (arrow) passing between the esophagus behind it and trachea in front of it. (c) Transverse T1-weighted MR image (750/30) obtained in another patient shows an anomalous left pulmonary artery (arrow) passing posteriorly and to the left between the trachea and the esophagus. Note the emphysematous right lung. The patient survived following surgical correction. (Image courtesy of S. Sane, MD, Minneapolis, Minn.) (d) Autopsy findings in an anomalous left artery, or pulmonary sling, with long-segment tracheal stenosis. Patient had an incidental coexistent anomalous right subclavian artery passing behind the esophagus. The tracheal stenosis, as viewed externally, is reflected in the change in diameter of the trachea involving approximately the last eight tracheal rings above the carina. Note the characteristic inverted "T" appearance of the splayed right and left main bronchi. L = left pulmonary artery, R = right pulmonary artery, S = anomalous subclavian artery. (Reprinted, with permission, from reference 11.) (e) Anteroposterior tracheobronchogram shows severe complete O-ring tracheal stenosis. Note the inverted trachea (T). The distal trachea is narrower than the bronchi. The patient, who also had a tracheal bronchus (arrow) to the right upper lobe, died after recurrent respiratory decompensations that seemed to be bronchiolitis. An anomalous left pulmonary artery was detected only at autopsy. (Image courtesy of B. Benjamin, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (f) Histologic trachea specimen obtained at autopsy in the patient in e shows complete O-ring tracheal stenosis. (Image courtesy of P. Bale, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (g) Three-dimensional reconstructed MR image (750/30) obtained in another patient, as viewed from above, shows an anomalous left pulmonary artery, or pulmonary sling. This patient also had an anomalous right subclavian artery as an incidental finding and tracheal stenosis from complete rings. The left pulmonary artery (L) arises from the right pulmonary artery (R) and passes to the left behind the trachea and left main bronchus (white). M = main pulmonary artery. (Image courtesy of Beverley Newman, MD, Children’s Hospital, Pittsburgh, Pa.)

View larger version (114K): [in this window] [in a new window] [Download PPT slide]   Figure 7b. (a) Diagram of anomalous left pulmonary artery, or pulmonary sling. Br. = bronchus, L.A. = ligamentous remnant of ductus arteriosus, L.L.L. = left lower lobe, L.P.A. = left pulmonary artery (in anomalous retrotracheal course), L.U.L. = left upper lobe, P.T. = pulmonary trunk, R.L.L. = right lower lobe, R.M.L. = right middle lobe, R.P.A. = right pulmonary artery, R.U.L. = right upper lobe. (Reprinted, with permission, from reference 18.) (b) Lateral airway esophagrams show an anomalous left pulmonary artery (arrow) passing between the esophagus behind it and trachea in front of it. (c) Transverse T1-weighted MR image (750/30) obtained in another patient shows an anomalous left pulmonary artery (arrow) passing posteriorly and to the left between the trachea and the esophagus. Note the emphysematous right lung. The patient survived following surgical correction. (Image courtesy of S. Sane, MD, Minneapolis, Minn.) (d) Autopsy findings in an anomalous left artery, or pulmonary sling, with long-segment tracheal stenosis. Patient had an incidental coexistent anomalous right subclavian artery passing behind the esophagus. The tracheal stenosis, as viewed externally, is reflected in the change in diameter of the trachea involving approximately the last eight tracheal rings above the carina. Note the characteristic inverted "T" appearance of the splayed right and left main bronchi. L = left pulmonary artery, R = right pulmonary artery, S = anomalous subclavian artery. (Reprinted, with permission, from reference 11.) (e) Anteroposterior tracheobronchogram shows severe complete O-ring tracheal stenosis. Note the inverted trachea (T). The distal trachea is narrower than the bronchi. The patient, who also had a tracheal bronchus (arrow) to the right upper lobe, died after recurrent respiratory decompensations that seemed to be bronchiolitis. An anomalous left pulmonary artery was detected only at autopsy. (Image courtesy of B. Benjamin, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (f) Histologic trachea specimen obtained at autopsy in the patient in e shows complete O-ring tracheal stenosis. (Image courtesy of P. Bale, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (g) Three-dimensional reconstructed MR image (750/30) obtained in another patient, as viewed from above, shows an anomalous left pulmonary artery, or pulmonary sling. This patient also had an anomalous right subclavian artery as an incidental finding and tracheal stenosis from complete rings. The left pulmonary artery (L) arises from the right pulmonary artery (R) and passes to the left behind the trachea and left main bronchus (white). M = main pulmonary artery. (Image courtesy of Beverley Newman, MD, Children’s Hospital, Pittsburgh, Pa.)

View larger version (133K): [in this window] [in a new window] [Download PPT slide]   Figure 7c. (a) Diagram of anomalous left pulmonary artery, or pulmonary sling. Br. = bronchus, L.A. = ligamentous remnant of ductus arteriosus, L.L.L. = left lower lobe, L.P.A. = left pulmonary artery (in anomalous retrotracheal course), L.U.L. = left upper lobe, P.T. = pulmonary trunk, R.L.L. = right lower lobe, R.M.L. = right middle lobe, R.P.A. = right pulmonary artery, R.U.L. = right upper lobe. (Reprinted, with permission, from reference 18.) (b) Lateral airway esophagrams show an anomalous left pulmonary artery (arrow) passing between the esophagus behind it and trachea in front of it. (c) Transverse T1-weighted MR image (750/30) obtained in another patient shows an anomalous left pulmonary artery (arrow) passing posteriorly and to the left between the trachea and the esophagus. Note the emphysematous right lung. The patient survived following surgical correction. (Image courtesy of S. Sane, MD, Minneapolis, Minn.) (d) Autopsy findings in an anomalous left artery, or pulmonary sling, with long-segment tracheal stenosis. Patient had an incidental coexistent anomalous right subclavian artery passing behind the esophagus. The tracheal stenosis, as viewed externally, is reflected in the change in diameter of the trachea involving approximately the last eight tracheal rings above the carina. Note the characteristic inverted "T" appearance of the splayed right and left main bronchi. L = left pulmonary artery, R = right pulmonary artery, S = anomalous subclavian artery. (Reprinted, with permission, from reference 11.) (e) Anteroposterior tracheobronchogram shows severe complete O-ring tracheal stenosis. Note the inverted trachea (T). The distal trachea is narrower than the bronchi. The patient, who also had a tracheal bronchus (arrow) to the right upper lobe, died after recurrent respiratory decompensations that seemed to be bronchiolitis. An anomalous left pulmonary artery was detected only at autopsy. (Image courtesy of B. Benjamin, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (f) Histologic trachea specimen obtained at autopsy in the patient in e shows complete O-ring tracheal stenosis. (Image courtesy of P. Bale, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (g) Three-dimensional reconstructed MR image (750/30) obtained in another patient, as viewed from above, shows an anomalous left pulmonary artery, or pulmonary sling. This patient also had an anomalous right subclavian artery as an incidental finding and tracheal stenosis from complete rings. The left pulmonary artery (L) arises from the right pulmonary artery (R) and passes to the left behind the trachea and left main bronchus (white). M = main pulmonary artery. (Image courtesy of Beverley Newman, MD, Children’s Hospital, Pittsburgh, Pa.)

View larger version (119K): [in this window] [in a new window] [Download PPT slide]   Figure 7d. (a) Diagram of anomalous left pulmonary artery, or pulmonary sling. Br. = bronchus, L.A. = ligamentous remnant of ductus arteriosus, L.L.L. = left lower lobe, L.P.A. = left pulmonary artery (in anomalous retrotracheal course), L.U.L. = left upper lobe, P.T. = pulmonary trunk, R.L.L. = right lower lobe, R.M.L. = right middle lobe, R.P.A. = right pulmonary artery, R.U.L. = right upper lobe. (Reprinted, with permission, from reference 18.) (b) Lateral airway esophagrams show an anomalous left pulmonary artery (arrow) passing between the esophagus behind it and trachea in front of it. (c) Transverse T1-weighted MR image (750/30) obtained in another patient shows an anomalous left pulmonary artery (arrow) passing posteriorly and to the left between the trachea and the esophagus. Note the emphysematous right lung. The patient survived following surgical correction. (Image courtesy of S. Sane, MD, Minneapolis, Minn.) (d) Autopsy findings in an anomalous left artery, or pulmonary sling, with long-segment tracheal stenosis. Patient had an incidental coexistent anomalous right subclavian artery passing behind the esophagus. The tracheal stenosis, as viewed externally, is reflected in the change in diameter of the trachea involving approximately the last eight tracheal rings above the carina. Note the characteristic inverted "T" appearance of the splayed right and left main bronchi. L = left pulmonary artery, R = right pulmonary artery, S = anomalous subclavian artery. (Reprinted, with permission, from reference 11.) (e) Anteroposterior tracheobronchogram shows severe complete O-ring tracheal stenosis. Note the inverted trachea (T). The distal trachea is narrower than the bronchi. The patient, who also had a tracheal bronchus (arrow) to the right upper lobe, died after recurrent respiratory decompensations that seemed to be bronchiolitis. An anomalous left pulmonary artery was detected only at autopsy. (Image courtesy of B. Benjamin, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (f) Histologic trachea specimen obtained at autopsy in the patient in e shows complete O-ring tracheal stenosis. (Image courtesy of P. Bale, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (g) Three-dimensional reconstructed MR image (750/30) obtained in another patient, as viewed from above, shows an anomalous left pulmonary artery, or pulmonary sling. This patient also had an anomalous right subclavian artery as an incidental finding and tracheal stenosis from complete rings. The left pulmonary artery (L) arises from the right pulmonary artery (R) and passes to the left behind the trachea and left main bronchus (white). M = main pulmonary artery. (Image courtesy of Beverley Newman, MD, Children’s Hospital, Pittsburgh, Pa.)

View larger version (134K): [in this window] [in a new window] [Download PPT slide]   Figure 7e. (a) Diagram of anomalous left pulmonary artery, or pulmonary sling. Br. = bronchus, L.A. = ligamentous remnant of ductus arteriosus, L.L.L. = left lower lobe, L.P.A. = left pulmonary artery (in anomalous retrotracheal course), L.U.L. = left upper lobe, P.T. = pulmonary trunk, R.L.L. = right lower lobe, R.M.L. = right middle lobe, R.P.A. = right pulmonary artery, R.U.L. = right upper lobe. (Reprinted, with permission, from reference 18.) (b) Lateral airway esophagrams show an anomalous left pulmonary artery (arrow) passing between the esophagus behind it and trachea in front of it. (c) Transverse T1-weighted MR image (750/30) obtained in another patient shows an anomalous left pulmonary artery (arrow) passing posteriorly and to the left between the trachea and the esophagus. Note the emphysematous right lung. The patient survived following surgical correction. (Image courtesy of S. Sane, MD, Minneapolis, Minn.) (d) Autopsy findings in an anomalous left artery, or pulmonary sling, with long-segment tracheal stenosis. Patient had an incidental coexistent anomalous right subclavian artery passing behind the esophagus. The tracheal stenosis, as viewed externally, is reflected in the change in diameter of the trachea involving approximately the last eight tracheal rings above the carina. Note the characteristic inverted "T" appearance of the splayed right and left main bronchi. L = left pulmonary artery, R = right pulmonary artery, S = anomalous subclavian artery. (Reprinted, with permission, from reference 11.) (e) Anteroposterior tracheobronchogram shows severe complete O-ring tracheal stenosis. Note the inverted trachea (T). The distal trachea is narrower than the bronchi. The patient, who also had a tracheal bronchus (arrow) to the right upper lobe, died after recurrent respiratory decompensations that seemed to be bronchiolitis. An anomalous left pulmonary artery was detected only at autopsy. (Image courtesy of B. Benjamin, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (f) Histologic trachea specimen obtained at autopsy in the patient in e shows complete O-ring tracheal stenosis. (Image courtesy of P. Bale, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (g) Three-dimensional reconstructed MR image (750/30) obtained in another patient, as viewed from above, shows an anomalous left pulmonary artery, or pulmonary sling. This patient also had an anomalous right subclavian artery as an incidental finding and tracheal stenosis from complete rings. The left pulmonary artery (L) arises from the right pulmonary artery (R) and passes to the left behind the trachea and left main bronchus (white). M = main pulmonary artery. (Image courtesy of Beverley Newman, MD, Children’s Hospital, Pittsburgh, Pa.)

View larger version (134K): [in this window] [in a new window] [Download PPT slide]   Figure 7f. (a) Diagram of anomalous left pulmonary artery, or pulmonary sling. Br. = bronchus, L.A. = ligamentous remnant of ductus arteriosus, L.L.L. = left lower lobe, L.P.A. = left pulmonary artery (in anomalous retrotracheal course), L.U.L. = left upper lobe, P.T. = pulmonary trunk, R.L.L. = right lower lobe, R.M.L. = right middle lobe, R.P.A. = right pulmonary artery, R.U.L. = right upper lobe. (Reprinted, with permission, from reference 18.) (b) Lateral airway esophagrams show an anomalous left pulmonary artery (arrow) passing between the esophagus behind it and trachea in front of it. (c) Transverse T1-weighted MR image (750/30) obtained in another patient shows an anomalous left pulmonary artery (arrow) passing posteriorly and to the left between the trachea and the esophagus. Note the emphysematous right lung. The patient survived following surgical correction. (Image courtesy of S. Sane, MD, Minneapolis, Minn.) (d) Autopsy findings in an anomalous left artery, or pulmonary sling, with long-segment tracheal stenosis. Patient had an incidental coexistent anomalous right subclavian artery passing behind the esophagus. The tracheal stenosis, as viewed externally, is reflected in the change in diameter of the trachea involving approximately the last eight tracheal rings above the carina. Note the characteristic inverted "T" appearance of the splayed right and left main bronchi. L = left pulmonary artery, R = right pulmonary artery, S = anomalous subclavian artery. (Reprinted, with permission, from reference 11.) (e) Anteroposterior tracheobronchogram shows severe complete O-ring tracheal stenosis. Note the inverted trachea (T). The distal trachea is narrower than the bronchi. The patient, who also had a tracheal bronchus (arrow) to the right upper lobe, died after recurrent respiratory decompensations that seemed to be bronchiolitis. An anomalous left pulmonary artery was detected only at autopsy. (Image courtesy of B. Benjamin, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (f) Histologic trachea specimen obtained at autopsy in the patient in e shows complete O-ring tracheal stenosis. (Image courtesy of P. Bale, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (g) Three-dimensional reconstructed MR image (750/30) obtained in another patient, as viewed from above, shows an anomalous left pulmonary artery, or pulmonary sling. This patient also had an anomalous right subclavian artery as an incidental finding and tracheal stenosis from complete rings. The left pulmonary artery (L) arises from the right pulmonary artery (R) and passes to the left behind the trachea and left main bronchus (white). M = main pulmonary artery. (Image courtesy of Beverley Newman, MD, Children’s Hospital, Pittsburgh, Pa.)

View larger version (164K): [in this window] [in a new window] [Download PPT slide]   Figure 7g. (a) Diagram of anomalous left pulmonary artery, or pulmonary sling. Br. = bronchus, L.A. = ligamentous remnant of ductus arteriosus, L.L.L. = left lower lobe, L.P.A. = left pulmonary artery (in anomalous retrotracheal course), L.U.L. = left upper lobe, P.T. = pulmonary trunk, R.L.L. = right lower lobe, R.M.L. = right middle lobe, R.P.A. = right pulmonary artery, R.U.L. = right upper lobe. (Reprinted, with permission, from reference 18.) (b) Lateral airway esophagrams show an anomalous left pulmonary artery (arrow) passing between the esophagus behind it and trachea in front of it. (c) Transverse T1-weighted MR image (750/30) obtained in another patient shows an anomalous left pulmonary artery (arrow) passing posteriorly and to the left between the trachea and the esophagus. Note the emphysematous right lung. The patient survived following surgical correction. (Image courtesy of S. Sane, MD, Minneapolis, Minn.) (d) Autopsy findings in an anomalous left artery, or pulmonary sling, with long-segment tracheal stenosis. Patient had an incidental coexistent anomalous right subclavian artery passing behind the esophagus. The tracheal stenosis, as viewed externally, is reflected in the change in diameter of the trachea involving approximately the last eight tracheal rings above the carina. Note the characteristic inverted "T" appearance of the splayed right and left main bronchi. L = left pulmonary artery, R = right pulmonary artery, S = anomalous subclavian artery. (Reprinted, with permission, from reference 11.) (e) Anteroposterior tracheobronchogram shows severe complete O-ring tracheal stenosis. Note the inverted trachea (T). The distal trachea is narrower than the bronchi. The patient, who also had a tracheal bronchus (arrow) to the right upper lobe, died after recurrent respiratory decompensations that seemed to be bronchiolitis. An anomalous left pulmonary artery was detected only at autopsy. (Image courtesy of B. Benjamin, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (f) Histologic trachea specimen obtained at autopsy in the patient in e shows complete O-ring tracheal stenosis. (Image courtesy of P. Bale, MD, Royal Alexandra Children’s Hospital, Sydney, Australia.) (g) Three-dimensional reconstructed MR image (750/30) obtained in another patient, as viewed from above, shows an anomalous left pulmonary artery, or pulmonary sling. This patient also had an anomalous right subclavian artery as an incidental finding and tracheal stenosis from complete rings. The left pulmonary artery (L) arises from the right pulmonary artery (R) and passes to the left behind the trachea and left main bronchus (white). M = main pulmonary artery. (Image courtesy of Beverley Newman, MD, Children’s Hospital, Pittsburgh, Pa.)

Modalities such as ultrafast electron-beam or spiral CT and MR imaging depict the vascular anatomy well (Fig 7g) and obviate angiography (14). The success of reconstructive procedures in the rigid trachea can be studied by using three-dimensional CT techniques, including virtual bronchoscopy.

Anomalous Right Subclavian Arterial Indentation: Normal Trachea with Oblique Posterior Esophageal Indentation (Dysplagia Lusoria)
Isolated posterior oblique indentation of the esophagus (Fig 8a) from an anomalous right subclavian artery should not be accepted as the cause of stridor in an infant. Although it is occasionally associated with swallowing problems (dysplagia lusoria) (Fig 9), it is usually asymptomatic and occurs in approximately one in 200 individuals. The anomalous right subclavian artery is always described as passing behind the esophagus. Actually, David Bayford (15,16), in his report in 1794, reported on a 63-year-old woman with lifelong swallowing problems in whom the necropsy specimens showed the artery passing between the trachea and the esophagus. As an apprentice surgeon in 1761, Bayford performed an autopsy on a patient whose esophagus was compressed by an aberrant right subclavian artery. He thought this was obstructed deglutition and coined it "dysplagia lusoria." This case went unrecorded until 1787 when Nathaniel Hulme, MD read an article in which Bayford’s case was being described before the Medical Society of London (14). The specimen was donated to the Hunterian Collection but it was lost over time (some speculate as the result of a bombing of London in World War II) (15). Was Bayford correct? We can only note that his illustrations are quite clear as to what he observed (Fig 8b).

View larger version (73K): [in this window] [in a new window] [Download PPT slide]   Figure 8a. (a) Typical lateral barium esophagram shows an anomalous right subclavian artery with a normal trachea. The indentation (arrow) in the esophagus is oblique and shallow. Solids are lodged in this area in an 8-year-old child who grew up consuming liquids only. The family refused surgery. (b) An illustration of dysphagia lusoria in a 62-year-old woman with lifelong obstructed deglutition, from the 1794 article by Bayford. Note the careful placement of the anomalous vessel (arrows) between the trachea and the esophagus on the anterior (top) and lateral (bottom) views. This is the always quoted so-called first reference on anomalous right subclavian artery. (Reprinted from reference 15.)

View larger version (63K): [in this window] [in a new window] [Download PPT slide]   Figure 8b. (a) Typical lateral barium esophagram shows an anomalous right subclavian artery with a normal trachea. The indentation (arrow) in the esophagus is oblique and shallow. Solids are lodged in this area in an 8-year-old child who grew up consuming liquids only. The family refused surgery. (b) An illustration of dysphagia lusoria in a 62-year-old woman with lifelong obstructed deglutition, from the 1794 article by Bayford. Note the careful placement of the anomalous vessel (arrows) between the trachea and the esophagus on the anterior (top) and lateral (bottom) views. This is the always quoted so-called first reference on anomalous right subclavian artery. (Reprinted from reference 15.)

View larger version (98K): [in this window] [in a new window] [Download PPT slide]   Figure 9a. (a) Lateral esophagram shows unusually prominent posterior indentation (arrow), from an anomalous right subclavian artery arising from a diverticulum, in the esophagus of an infant who had feeding problems. The airway is normal. (b) Original image of the Kommerell diverticulum, with an anomalous right subclavian artery arising from the diverticulum off the left aortic arch (posterior view). (Reprinted, with permission, from reference 17.) (c, d) T1-weighted MR images (750/30) obtained in the patient in a. (c) Coronal image shows a normal trachea. (d) More posterior coronal image shows a diverticulum (arrow) arising from the right side of the left descending aorta. The diverticulum gave rise to an anomalous right subclavian artery.

View larger version (85K): [in this window] [in a new window] [Download PPT slide]   Figure 9b. (a) Lateral esophagram shows unusually prominent posterior indentation (arrow), from an anomalous right subclavian artery arising from a diverticulum, in the esophagus of an infant who had feeding problems. The airway is normal. (b) Original image of the Kommerell diverticulum, with an anomalous right subclavian artery arising from the diverticulum off the left aortic arch (posterior view). (Reprinted, with permission, from reference 17.) (c, d) T1-weighted MR images (750/30) obtained in the patient in a. (c) Coronal image shows a normal trachea. (d) More posterior coronal image shows a diverticulum (arrow) arising from the right side of the left descending aorta. The diverticulum gave rise to an anomalous right subclavian artery.

View larger version (94K): [in this window] [in a new window] [Download PPT slide]   Figure 9c. (a) Lateral esophagram shows unusually prominent posterior indentation (arrow), from an anomalous right subclavian artery arising from a diverticulum, in the esophagus of an infant who had feeding problems. The airway is normal. (b) Original image of the Kommerell diverticulum, with an anomalous right subclavian artery arising from the diverticulum off the left aortic arch (posterior view). (Reprinted, with permission, from reference 17.) (c, d) T1-weighted MR images (750/30) obtained in the patient in a. (c) Coronal image shows a normal trachea. (d) More posterior coronal image shows a diverticulum (arrow) arising from the right side of the left descending aorta. The diverticulum gave rise to an anomalous right subclavian artery.

View larger version (98K): [in this window] [in a new window] [Download PPT slide]   Figure 9d. (a) Lateral esophagram shows unusually prominent posterior indentation (arrow), from an anomalous right subclavian artery arising from a diverticulum, in the esophagus of an infant who had feeding problems. The airway is normal. (b) Original image of the Kommerell diverticulum, with an anomalous right subclavian artery arising from the diverticulum off the left aortic arch (posterior view). (Reprinted, with permission, from reference 17.) (c, d) T1-weighted MR images (750/30) obtained in the patient in a. (c) Coronal image shows a normal trachea. (d) More posterior coronal image shows a diverticulum (arrow) arising from the right side of the left descending aorta. The diverticulum gave rise to an anomalous right subclavian artery.

OTHER THINGS

Airway Obstruction from Congenital Absence of the Pulmonary Valve with Bronchial Obstruction
Airway obstruction caused by congenital absence of the pulmonary valve (18–20), a fascinating cardiac lesion, occurs as a variant of tetralogy of Fallot, with a ventricular septal defect, thickening of the pulmonary valve annulus with dysplastic leaflets, and massive pulmonary insufficiency (Fig 10a). On conventional radiographs obtained in infants, the huge, massively dilated pulmonary arteries are shown to cause bronchial compression with obstructive emphysema (Fig 10b). There may be fluid retention on the initial neonatal chest radiographs (Fig 10b, 10c). Many such infants die without a proper diagnosis and are thought to have had a nonsurgical cause of respiratory distress. Echocardiography is the primary diagnostic tool (Fig 10d, 10e), although electron-beam or spiral CT or MR imaging can help make the diagnosis. Airway obstruction from congenital absence of the pulmonary valve with bronchial obstruction has also been detected at prenatal ultrasonography. The airway compression is best seen at CT.

View larger version (67K): [in this window] [in a new window] [Download PPT slide]   Figure 10a. (a) Diagram illustrates absence of the pulmonary valve, with huge central pulmonary arteries compressing the main bronchi. Br. = bronchus, L.L.L. = left lower lobe, L.P.A. = left pulmonary artery, L.U.L. = left upper lobe, P.T. = pulmonary trunk, R.L.L. = right lower lobe, R.M.L. = right middle lobe, R.P.A. = right pulmonary artery, R.U.L. = right upper lobe. (Reprinted, with permission, from reference 18.) (b, c) Radiographs show absent pulmonary valve with retained fetal lung fluid from airway obstruction. (b) Anteroposterior radiograph shows an opaque right lung. (c) Anteroposterior radiograph obtained 8 hours later shows hyperinflation. Note the right hilar mass on the dilated right pulmonary artery (arrow). (d) Echocardiogram in the subxiphoid long-axis projection shows a huge main pulmonary artery (MPA). Only dysplastic valve tissue is seen on real-time studies with massive pulmonary insufficiency. (e) Echocardiogram in the subxiphoid ventricular short-axis projection, obtained in the patient in e, shows outflow annulus narrowing (arrow) below the huge main pulmonary artery (MPA). The patient survived after undergoing valve replacement and reduction of the central aneurysm of pulmonary arteries. (Images in d and e courtesy of F. Bierman, MD, New York, NY.)

View larger version (137K): [in this window] [in a new window] [Download PPT slide]   Figure 10b. (a) Diagram illustrates absence of the pulmonary valve, with huge central pulmonary arteries compressing the main bronchi. Br. = bronchus, L.L.L. = left lower lobe, L.P.A. = left pulmonary artery, L.U.L. = left upper lobe, P.T. = pulmonary trunk, R.L.L. = right lower lobe, R.M.L. = right middle lobe, R.P.A. = right pulmonary artery, R.U.L. = right upper lobe. (Reprinted, with permission, from reference 18.) (b, c) Radiographs show absent pulmonary valve with retained fetal lung fluid from airway obstruction. (b) Anteroposterior radiograph shows an opaque right lung. (c) Anteroposterior radiograph obtained 8 hours later shows hyperinflation. Note the right hilar mass on the dilated right pulmonary artery (arrow). (d) Echocardiogram in the subxiphoid long-axis projection shows a huge main pulmonary artery (MPA). Only dysplastic valve tissue is seen on real-time studies with massive pulmonary insufficiency. (e) Echocardiogram in the subxiphoid ventricular short-axis projection, obtained in the patient in e, shows outflow annulus narrowing (arrow) below the huge main pulmonary artery (MPA). The patient survived after undergoing valve replacement and reduction of the central aneurysm of pulmonary arteries. (Images in d and e courtesy of F. Bierman, MD, New York, NY.)

View larger version (135K): [in this window] [in a new window] [Download PPT slide]   Figure 10c. (a) Diagram illustrates absence of the pulmonary valve, with huge central pulmonary arteries compressing the main bronchi. Br. = bronchus, L.L.L. = left lower lobe, L.P.A. = left pulmonary artery, L.U.L. = left upper lobe, P.T. = pulmonary trunk, R.L.L. = right lower lobe, R.M.L. = right middle lobe, R.P.A. = right pulmonary artery, R.U.L. = right upper lobe. (Reprinted, with permission, from reference 18.) (b, c) Radiographs show absent pulmonary valve with retained fetal lung fluid from airway obstruction. (b) Anteroposterior radiograph shows an opaque right lung. (c) Anteroposterior radiograph obtained 8 hours later shows hyperinflation. Note the right hilar mass on the dilated right pulmonary artery (arrow). (d) Echocardiogram in the subxiphoid long-axis projection shows a huge main pulmonary artery (MPA). Only dysplastic valve tissue is seen on real-time studies with massive pulmonary insufficiency. (e) Echocardiogram in the subxiphoid ventricular short-axis projection, obtained in the patient in e, shows outflow annulus narrowing (arrow) below the huge main pulmonary artery (MPA). The patient survived after undergoing valve replacement and reduction of the central aneurysm of pulmonary arteries. (Images in d and e courtesy of F. Bierman, MD, New York, NY.)

View larger version (132K): [in this window] [in a new window] [Download PPT slide]   Figure 10d. (a) Diagram illustrates absence of the pulmonary valve, with huge central pulmonary arteries compressing the main bronchi. Br. = bronchus, L.L.L. = left lower lobe, L.P.A. = left pulmonary artery, L.U.L. = left upper lobe, P.T. = pulmonary trunk, R.L.L. = right lower lobe, R.M.L. = right middle lobe, R.P.A. = right pulmonary artery, R.U.L. = right upper lobe. (Reprinted, with permission, from reference 18.) (b, c) Radiographs show absent pulmonary valve with retained fetal lung fluid from airway obstruction. (b) Anteroposterior radiograph shows an opaque right lung. (c) Anteroposterior radiograph obtained 8 hours later shows hyperinflation. Note the right hilar mass on the dilated right pulmonary artery (arrow). (d) Echocardiogram in the subxiphoid long-axis projection shows a huge main pulmonary artery (MPA). Only dysplastic valve tissue is seen on real-time studies with massive pulmonary insufficiency. (e) Echocardiogram in the subxiphoid ventricular short-axis projection, obtained in the patient in e, shows outflow annulus narrowing (arrow) below the huge main pulmonary artery (MPA). The patient survived after undergoing valve replacement and reduction of the central aneurysm of pulmonary arteries. (Images in d and e courtesy of F. Bierman, MD, New York, NY.)

View larger version (131K): [in this window] [in a new window] [Download PPT slide]   Figure 10e. (a) Diagram illustrates absence of the pulmonary valve, with huge central pulmonary arteries compressing the main bronchi. Br. = bronchus, L.L.L. = left lower lobe, L.P.A. = left pulmonary artery, L.U.L. = left upper lobe, P.T. = pulmonary trunk, R.L.L. = right lower lobe, R.M.L. = right middle lobe, R.P.A. = right pulmonary artery, R.U.L. = right upper lobe. (Reprinted, with permission, from reference 18.) (b, c) Radiographs show absent pulmonary valve with retained fetal lung fluid from airway obstruction. (b) Anteroposterior radiograph shows an opaque right lung. (c) Anteroposterior radiograph obtained 8 hours later shows hyperinflation. Note the right hilar mass on the dilated right pulmonary artery (arrow). (d) Echocardiogram in the subxiphoid long-axis projection shows a huge main pulmonary artery (MPA). Only dysplastic valve tissue is seen on real-time studies with massive pulmonary insufficiency. (e) Echocardiogram in the subxiphoid ventricular short-axis projection, obtained in the patient in e, shows outflow annulus narrowing (arrow) below the huge main pulmonary artery (MPA). The patient survived after undergoing valve replacement and reduction of the central aneurysm of pulmonary arteries. (Images in d and e courtesy of F. Bierman, MD, New York, NY.)

SUMMARY

Radiology has played a crucial role in delineating vascular causes of airway obstruction—that is, rings, slings, and other things—in infants, from the 1940s with conventional radiographs and barium esophagrams, through the 1960s–1970s with angiography, to the 1980s and 1990s with CT and MR imaging. These modalities have facilitated more precise diagnosis and thus led to earlier treatment and better outcome. These advances represent a triumph in the care of critically ill infants with respiratory distress and a marvelous legacy of Drs Gross and Neuhauser.

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