3He diffusion MRI in human lungs.

Hyperpolarized 3He gas allows the air spaces of the lungs to be imaged via MRI. Imaging of restricted diffusion is addressed here, which allows the microstructure of the lung to be characterized through the physical restrictions to gas diffusion presented by airway and alveolar walls in the lung. Measurements of the apparent diffusion coefficient (ADC) of 3He at time scales of milliseconds and seconds are compared; measurement of acinar airway sizes by determination of the microscopic anisotropy of diffusion is discussed. This is where Dr. JJH Ackerman's influence was greatest in aiding the formation of the Washington University 3He group, involving early a combination of physicists, radiologists, and surgeons, as the first applications of 3He ADC were to COPD and its destruction/modification of lung microstructure via emphysema. The sensitivity of the method to early COPD is demonstrated, as is its validation by direct comparison to histology. More recently the method has been used broadly in adult and pediatric obstructive lung diseases, from severe asthma to cystic fibrosis to bronchopulmonary dysplasia, a result of premature birth. These applications of the technique are discussed briefly.

The use of omental pedicle flap for tracheobronchial reconstruction in infants and children.

For the surgical repair of long-segment tracheal stenosis, costal cartilage graft or extensive resection with end-to-end anastomosis has often been used. Both procedures have a risk of developing anastomotic leakage, which is potentially a lethal complication, or stenosis resulting from compromised blood supply to the tissue at the anastomosis. We have used omental pedicle flap (OPF) to seal the anastomotic line and to restore the vascularity of the graft and the trachea in an attempt to avoid fatal complications. During the period between 1986 and 1990, OPF technique was used in tracheobronchial reconstruction in six patients aged 4 months to 3 years; cartilage graft for extensive tracheal stenosis (4), tracheal resection and anastomosis (1), and bronchial resection and anastomosis (1). The omentum was separated from the colon to form an OPF with the right gastroepiploic vessels preserved. The OPF was brought to the upper trachea in the mediastinum through the retrosternal space. There was no immediate postoperative death due to anastomotic leak. Endotrachial tubes were removed in all patients. Four of the six are totally free of airway problems. One patient showed persistent stridor because of remaining stenosis at the cervical trachea. The remaining one patient who underwent bronchial resection developed anastomotic stenosis probably due to the compression of the floppy left main bronchus by adjacent aorta. The OPF seems to be an important surgical adjunct in order to eliminate fatal complications in tracheobronchial reconstruction.

Fetal thoracic and bladder shunts.

Congenital obstructive lesions involving the bladder and the lung can lead to serious complications for the newborn. The in-utero placement of a diverting shunt in the fetal bladder or thoracic cavity can decrease the morbidity and mortality associated with these obstructive conditions. This review focuses on the indications for prenatal evaluation, technique, and outcomes for those fetuses with a lower urinary tract obstruction, congenital pleural effusion or macrocystic congenital cystic adenomatoid malformation after placement of a vesicoamniotic or thoracoamniotic shunt.

[Congenital lung hypoplasia in adulthood]. / Kongenitale Lungenhypoplasie im Erwachsenenalter.

This is a report on a largely asymptomatic patient with a unilaterally non-functional lung. The differential diagnosis between an acquired, "destroyed" lung and congenital hypoplasia of the lung with secondary inflammatory changes proves difficult. The various imaging procedures that are available, used in conjunction with the histological findings, permit a classification.

Absence of a hemidiaphragm: mechanical implications.

Respiratory system mechanics were evaluated in a 22-year-old asymptomatic man with absence of the left hemidiaphragm. We described changes in esophageal pressure (Pes), gastric pressure (Pga), chest wall configuration, and mediastinal motion during tidal breathing, breaths to total lung capacity (TLC), and Mueller maneuvers in the upright and supine position. We predicted that contraction of the single hemidiaphragm would drive the abdominal contents caudal on the side with the intact hemidiaphragm and displace the abdominal contents cephalad on the other side. This would drive the mediastinum toward the side with the intact diaphragm, thereby reducing its effectiveness in expanding the lung on that side. When upright, this effect would be minimized to the extent that the rib cage muscles lower pleural pressure in the thorax without the diaphragm. We found that (vital capacity) VC and TLC were greater upright than supine and that Pga deflections were almost as strongly negative as Pes deflections during upright quiet breathing and breaths to TLC. Thus the rib cage muscles enhanced the inspiratory action of the right hemidiaphragm in the upright position. In the supine position, Pes became negative without change of Pga during breaths to TLC and quiet inspirations. Here, contraction of the hemidiaphragm was the dominant mechanism generating the inspiratory pressure. During maximal Mueller efforts, the mediastinum shifted toward the side with the intact diaphragm in both positions and the maximum inspiratory pressures were low. These pressures were likely to have been limited by both the finite impedance to rotation of the thoracoabdominal contents or mediastinum and a mechanical disadvantage of the remaining hemidiaphragm. We conclude that the effectiveness of the single hemidiaphragm as an inspiratory pump requires passive impedance of the abdominal viscera and mediastinum and is enhanced in the upright position by the action of the rib cage muscles.

[Diagnosis of congenital tracheo-bronchial malformations in the newborn and infant]. / Le diagnostic des malformations congénitales trachéo-bronchiques du nouveau-né et du nourrisson.

Diagnosis endoscopy in congenital tracheo-bronchial abnormalities. High quality of anesthesia and efficiency of light sources and optical systems, now allow safe examination of upper respiratory tract and ability to give very precise informations in neonates and infants. Endoscopy now is then an essential procedure for diagnostic of congenital anomalies of respiratory tract. The necessary conditions for a safe examination and the necessity of complete exploration are exposed as well as endoscopic aspects of various congenital anomalies.

Cost-effectiveness of alpha-1 antitrypsin replacement therapy in treatment of congenital chronic obstructive pulmonary disease.

BACKGROUND: Alpha 1-antitrypsin (AAT) replacement therapy is an expensive intervention ($20,000-$30,000 per patient annually) which may slow or arrest the progression of chronic obstructive pulmonary disease (COPD) in AAT-deficient patients. While FDA-approved, therapy efficacy is unknown. The costs and benefits of AAT replacement therapy were evaluated for patients with congenital COPD. METHODS: Epidemiological and disease cost data were taken from published sources. A discrete-time model of disease stage probability transition was developed to calculate the present-value expected cost of disease treatment, under a range of possible therapy efficacy and other parameter values. RESULTS: At an efficacy of 70 percent, the cost per life year saved with AAT replacement therapy would be between $28,000 and $72,000 (1990 US dollars), depending on patient age, sex, and smoking status. At 30 percent efficacy, the cost per life year saved range would be between $50,000 and $128,000. A controlled efficacy study would cost $53 million or less, if the true efficacy were 50 percent or better. CONCLUSIONS: With efficacy of 30 percent or higher, therapy cost-effectiveness would be comparable to other widely used medical interventions. The economic assessment methodology was used to evaluate both the therapeutic innovation and the value of additional clinical research.

Congenital pulmonary lymphangiectasis.

We have described an unusual case of congenital pulmonary lymphangiectasis which does not conform to Felman's classification. We suggest establishing a third category in the group with non-cardiac-associated CPL, entitled "noncardiac, intermediate onset."

[Hyperlucent pulmonary areas caused by stenosis or bronchial atresia in children]. / Hyperclartés pulmonaires de l'enfant par sténose ou atrésie bronchique.

From 1976 to 1979, 4 congenital bronchial abnormalities (1 stenosis, 3 atresias) have been observed and cured at Hospital des Enfants Malades Paris. The pulmonary distension with impaction of mucous secretion evocates the diagnosis. The bronchography shows the stenosis of the atresia. The pulmonary function testing confirms the hypoperfusion and the hypoventilation. The surgical indication is done in order to prevent complications and to suppress the compression of the lung. The results are good. The pulmonary testing function is correct long while after the operation. The authors discuss the surgical indication in function of the increasing of the lung.

[Findings of combined ventilation/perfusion scintigraphy in children with abnormalities of the bronchi, the lung and lung blood vessels]. / Befunde der kombinierten Ventilations-/Perfusionsszintigraphie bei Kindern mit Fehlbildungen der Bronchien, der Lungen und Lungengefässe.

Combined ventilation/perfusion scintigraphy with 133Xe/99mTc-HAM was performed within the framework of bronchological diagnostics in 38 children suffering from malformations of the bronchi, lungs and pulmonary vessels, and in 9 children after surgery of hernia of the diaphragm. The findings in stenoses, cysts in the bronchial system and in children with pulmonary vessel malformations, in one child with pulmonary agenesia and in a few other malformations, are presented. The significance of these findings in bronchological diagnosis in case of pulmonary malformations or clinical follow-up is discussed. Combined ventilation/perfusion scintigraphy is a valuable contribution to preliminary diagnosis and in follow-up of children with pulmonary malformations.