Effects of tracheal occlusion on the neonatal cardiopulmonary transition in an ovine model of diaphragmatic hernia

2019 ◽  
Vol 104 (6) ◽  
pp. F609-F616 ◽  
Author(s):  
Philip L J DeKoninck ◽  
Kelly J Crossley ◽  
Aidan J Kashyap ◽  
Sasha M Skinner ◽  
Marta Thio ◽  
...  
Keyword(s):  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Diaphragmatic Hernia ◽  
Weight Ratio ◽  
Lung Compliance ◽  
Ovine Model ◽  
Lung Weight ◽  
Tracheal Occlusion ◽  
Arterial Blood Gas ◽  
Arterial Blood

ObjectiveFetoscopic endoluminal tracheal occlusion (FETO) aims to reverse pulmonary hypoplasia associated with congenital diaphragmatic hernia (CDH) and mitigate the associated respiratory insufficiency and pulmonary hypertension after birth. We aimed to determine whether FETO improves the cardiopulmonary transition at birth in an ovine model of CDH.MethodsIn 12 ovine fetuses with surgically induced diaphragmatic hernia (DH; 80 dGA), an endotracheal balloon was placed tracheoscopically at ≈110 dGA and removed at ≈131 dGA (DH+FETO), while 10 were left untreated (DH). At ≈138 dGA, all lambs (survival at delivery: 67% [DH+FETO], 70% [DH]) were delivered via caesarean section and ventilated for 2 hours. Physiological and ventilation parameters were continuously recorded, and arterial blood-gas values were measured.ResultsCompared with DH, DH+FETO lambs had increased wet lung-to-body-weight ratio (0.031±0.004 vs 0.016±0.002) and dynamic lung compliance (0.7±0.1 vs 0.4±0.1 mL/cmH2O). Pulmonary vascular resistance was lower in DH+FETO lambs (0.44±0.11 vs 1.06±0.17 mm Hg/[mL/min]). However, after correction for lung weight, pulmonary blood flow was not significantly different between the groups (4.19±0.57 vs 4.05±0.60 mL/min/g). Alveolar–arterial difference in oxygen tension was not significantly different between DH+FETO and DH (402±41mm Hg vs 401±45 mm Hg).ConclusionsFETO accelerated lung growth in fetuses with CDH and improved neonatal respiratory function during the cardiopulmonary transition at birth. However, despite improved lung compliance and reduced pulmonary vascular resistance, there were less pronounced benefits for gas exchange during the first 2 hours of life.

Neonatal cardiopulmonary transition in an ovine model of congenital diaphragmatic hernia

2019 ◽  
Vol 104 (6) ◽  
pp. F617-F623 ◽  
Author(s):  
Aidan J Kashyap ◽  
Kelly J Crossley ◽  
Philip L J DeKoninck ◽  
Karyn A Rodgers ◽  
Marta Thio ◽  
...  
Keyword(s):  
Congenital Diaphragmatic Hernia ◽  
Diaphragmatic Hernia ◽  
Cerebral Oxygenation ◽  
Weight Ratio ◽  
Respiratory Acidosis ◽  
Tissue Oxygen Saturation ◽  
Lung Hypoplasia ◽  
Ovine Model ◽  
Lung Weight ◽  
Arterial Blood

ObjectiveInfants with a congenital diaphragmatic hernia (CDH) are at high risk of developing pulmonary hypertension after birth, but little is known of their physiological transition at birth. We aimed to characterise the changes in cardiopulmonary physiology during the neonatal transition in an ovine model of CDH.MethodsA diaphragmatic hernia (DH) was surgically created at 80 days of gestational age (dGA) in 10 fetuses, whereas controls underwent sham surgery (n=6). At 138 dGA, lambs were delivered via caesarean section and ventilated for 2 hours. Physiological and ventilation parameters were continuously recorded, and arterial blood gas values were measured.ResultsDH lambs had lower wet lung-to-body-weight ratio (0.016±0.002vs0.033±0.004), reduced dynamic lung compliance (0.4±0.1mL/cmH2O vs1.2±0.1 mL/cmH2O) and reduced arterial pH (7.11±0.05vs7.26±0.05), compared with controls. While measured pulmonary blood flow (PBF) was lower in DH lambs, after correction for lung weight, PBF was not different between groups (4.05±0.60mL/min/gvs4.29±0.57 mL/min/g). Cerebral tissue oxygen saturation was lower in DH compared with control lambs (55.7±3.5vs67.7%±3.9%).ConclusionsImmediately after birth, DH lambs have small, non-compliant lungs, respiratory acidosis and poor cerebral oxygenation that reflects the clinical phenotype of human CDH. PBF (indexed to lung weight) was similar in DH and control lambs, suggesting that the reduction in PBF associated with CDH is proportional to the degree of lung hypoplasia during the neonatal cardiopulmonary transition.

scholarly journals Changes in the Expression of Vascular Endothelial Growth Factor after Fetal Tracheal Occlusion in an Experimental Model of Congenital Diaphragmatic Hernia

2013 ◽  
Vol 2013 ◽  
pp. 1-6
Author(s):  
E. Sanz-López ◽  
E. Maderuelo ◽  
D. Peláez ◽  
P. Chimenti ◽  
R. Lorente ◽  
...  
Keyword(s):  
Vascular Endothelial Growth Factor ◽  
Growth Factor ◽  
Congenital Diaphragmatic Hernia ◽  
Diaphragmatic Hernia ◽  
Weight Ratio ◽  
Angiogenic Factor ◽  
Vascular Endothelial ◽  
Lung Weight ◽  
Tracheal Occlusion ◽  
Endothelial Growth Factor

Introduction. Vascular endothelial growth factor (VEGF), an angiogenic factor secreted by type II pneumocytes, could play a role in congenital diaphragmatic hernia (CDH) pathogenesis. Animal studies suggest that VEGF accelerates lung growth.Aim. To quantify VEGF on fetal lungs in a nitrofen rat model for CDH and to analyze the effect of tracheal occlusion (TO) in VEGF in fetal lung rats after nitrofen and in control rats not exposed to nitrofen.Methods. Pregnant rats received nitrofen on day 9.5 of gestation. Fetuses were divided into 2 groups: those that underwent TO on day 20 and those that did not. On day 21, fetuses were delivered, and the lungs were dissected for subsequent VEGF quantification.Results. CDH was detected in 43% of the fetuses that received nitrofen. Fetuses with CDH showed significantly reduced lung weight/fetal weight ratio and lower VEGF levels than the remainder. A higher VEGF value was observed after TO.Conclusions. VEGF protein was significantly lower in fetuses with CDH. TO induced a significant increase in VEGF compared to the fetuses that did not undergo TO. Although not statistically significant, we observed higher VEGF levels in fetuses with CDH and TO compared to fetuses with CDH and no further intervention.

Fetal tracheal occlusion in the rat model of nitrofen-induced congenital diaphragmatic hernia

1999 ◽  
Vol 87 (2) ◽  
pp. 769-775 ◽  
Author(s):  
Yoshihiro Kitano ◽  
Paul Davies ◽  
Daniel von Allmen ◽  
N. Scott Adzick ◽  
Alan W. Flake
Keyword(s):  
Congenital Diaphragmatic Hernia ◽  
Diaphragmatic Hernia ◽  
Rat Model ◽  
Weight Ratio ◽  
Lung Parenchyma ◽  
Lung Hypoplasia ◽  
Lung Growth ◽  
Lung Weight ◽  
Pregnant Rats ◽  
Tracheal Occlusion

Prenatal tracheal occlusion (TO) consistently accelerates lung growth in the sheep model of congenital diaphragmatic hernia (CDH). However, significant variability in lung growth has been observed in early clinical trials of TO. We hypothesized that lung hypoplasia created at relatively late stages of lung development may not be equivalent to human CDH-induced lung hypoplasia, which begins early in gestation. To test this hypothesis, we performed TO in the rat model of nitrofen-induced CDH. Left-sided CDH was induced by administering 100 mg of nitrofen to timed pregnant rats on day 9 of gestation. On day 19 of gestation, four to five fetuses per dam underwent surgical ligation of the trachea. At death ( day 21.5), lungs from non-CDH (non-CDH group), left-CDH (CDH group), and trachea-occluded left-CDH fetuses (CDH-TO group) were harvested and compared by weight, DNA and protein content, and stereological morphometry. Wet and dry lung weight-to-body weight ratio, total lung DNA and protein contents, the volume of lung parenchyma, and the total saccular surface area of the CDH-TO group were significantly increased relative to the CDH group and were either greater than or comparable to the non-CDH controls. We conclude that TO accelerates lung growth and increases lung parenchyma in an early-onset model of CDH-induced lung hypoplasia.

Effects of chest compression on reflex ventilatory drive and pulmonary function

1962 ◽  
Vol 17 (4) ◽  
pp. 701-705 ◽  
Author(s):  
Malcolm B. McIlroy ◽  
John Butler ◽  
Theodore N. Finley
Keyword(s):  
Chest Compression ◽  
Lung Volume ◽  
Transpulmonary Pressure ◽  
Normal Subjects ◽  
Lung Compliance ◽  
External Compression ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Ventilatory Drive ◽  
Anatomical Dead Space

External compression of the chest sufficient to reduce the lung volume (FRC) by 1 liter in eight normal subjects interfered with the mechanical function of the lungs. We have confirmed the findings of Caro et al. ( J. Clin. Invest. 39: 573, 1960), who showed a decrease in lung compliance and an increase in respiratory rate. Neither returned to normal when the compressing force was removed, and it was not until the subject took a deep breath that the lungs returned to their control state. We also found a reduction in anatomical dead space and alveolar hyperventilation. Arterial blood gas tensions showed evidence of complex ventilation-perfusion abnormalities, which could not be explained by any single factor. We think the hyperventilation associated with chest compression is reflex in origin and related to a decrease in lung volume rather than to any change in transpulmonary pressure. Submitted on January 4, 1962

Platelet-activating factor modulates pulmonary vasomotor tone in the perinatal lamb

1998 ◽  
Vol 85 (3) ◽  
pp. 1079-1085 ◽  
Author(s):  
Basil O. Ibe ◽  
Sue Hibler ◽  
J. Usha Raj
Keyword(s):  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Platelet Activating Factor ◽  
Perinatal Period ◽  
Arterial Blood Flow ◽  
Vasomotor Tone ◽  
Arterial Blood ◽  
Determine Role ◽  
Pulmonary Arterial ◽  
Near Term

Eight near-term fetal lambs were studied acutely in utero to determine role of platelet-activating factor (PAF) in the regulation of vasomotor tone in systemic and pulmonary circulations in the immediate perinatal period. Four fetal lambs were studied predelivery and 2 h postdelivery to determine circulating PAF levels. Aortic and pulmonary arterial pressures and cardiac output were measured continuously, and systemic and pulmonary vascular resistances were calculated. Left pulmonary arterial blood flow was also measured in four fetal lambs. After delivery and oxygenation, circulating PAF levels fell significantly. When WEB-2170, a specific PAF-receptor antagonist, was infused to block effect of endogenous PAF in the eight near-term fetal lambs, systemic vascular resistance fell 30% but pulmonary vascular resistance fell dramatically by 68%. Specificity of WEB-2170 was tested in juvenile lambs and was found to be very specific in lowering vasomotor tone only when tone was elevated by action of PAF. Our data show that endogenous PAF levels in the fetus contribute to maintain a high basal systemic and pulmonary vasomotor tone and that a normal fall in circulating PAF levels after birth and oxygenation may facilitate fall in pulmonary vascular resistance at birth.

Pulmonary blood flow, pressure and resistance following tetraethylammonium and aminophylline

1961 ◽  
Vol 200 (2) ◽  
pp. 287-291 ◽  
Author(s):  
M. Harasawa ◽  
S. Rodbard
Keyword(s):  
Blood Flow ◽  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Systemic Blood Pressure ◽  
Arterial Blood Flow ◽  
Tetraethylammonium Chloride ◽  
Blood Flows ◽  
Arterial Blood ◽  
Pulmonary Arterial ◽  
Flow Pressure

The effects of tetraethylammonium chloride (TEAC) and aminophylline on the pulmonary vascular resistance were studied in thoracotomized dogs. Pulmonary arterial blood flow and pressure, and systemic blood pressure were measured simultaneously. Both drugs showed marked hypotensive effects on the systemic vessels. In every instance pulmonary arterial pressures and blood flows were reduced by TEAC given via the pulmonary artery and increased by aminophylline. However, the calculated pulmonary vascular resistance remained essentially unchanged in all experiments. These data challenge the concept that the pulmonary vessels respond to these drugs by active vasodilatation

Lung Pathology in Patients with Congenital Diaphragmatic Hernia Treated with Fetal Surgical Intervention, Including Tracheal Occlusion

2003 ◽  
Vol 6 (6) ◽  
pp. 536-546 ◽  
Author(s):  
Amy E. Heerema ◽  
Joseph T. Rabban ◽  
Roman M. Sydorak ◽  
Micheal R. Harrison ◽  
Kirk D. Jones
Keyword(s):  
Body Weight ◽  
Congenital Diaphragmatic Hernia ◽  
Diaphragmatic Hernia ◽  
Pulmonary Hypoplasia ◽  
Weight Ratio ◽  
Lung Pathology ◽  
Body Weight Ratio ◽  
Fetal Intervention ◽  
Tracheal Occlusion ◽  
Significant Difference

Fetal intervention for congenital diaphragmatic hernia was developed to lessen the high morbidity and mortality of pulmonary hypoplasia. Lung pathology and morphometry in patients treated with fetal intervention have not been described. We report clinical and autopsy findings, as well as basic lung morphometry in 16 cases of congenital diaphragmatic hernia with fetal intervention (12 cases tracheal occlusion; 4 cases hernia repair), and 19 cases of congenital diaphragmatic hernia without fetal intervention. All patients who underwent fetal intervention were born premature. Lung enlargement with increased lung-to-body weight ratio was observed with fetal tracheal occlusion, accompanied by lower than normal radial alveolar counts and increased alveolar size. Patients treated with tracheal occlusion also had early alveolar development (at 29.8, 30.6, and 30.9 wk postconceptual age) as well as mucous fluid pooling in airways and alveoli. All cases showed severe alveolar septal widening, more extensive in patients without fetal intervention. When grouped by postconceptual age, no statistically significant difference was found between patients with and without fetal intervention with respect to lung-to-body weight ratio, radial alveolar count, mean alveolar length, and relative arteriolar media thickness. Lung enlargement has been observed with fetal tracheal occlusion sonographically; our studies suggest that this is due in part to emphysema and mucous fluid pooling. The lung remains abnormal with low radial alveolar counts and increased alveolar size. Tracheal occlusion did not prevent development of lung pathology associated with pulmonary hypoplasia.

Effect of high intra-alveolar O2 tensions on pulmonary circulation in perfused lungs of dogs

1965 ◽  
Vol 208 (1) ◽  
pp. 130-138 ◽  
Author(s):  
G. J. A. Cropp
Keyword(s):  
Blood Flow ◽  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Pulmonary Circulation ◽  
Time Course ◽  
Systemic Circulation ◽  
The Body ◽  
Arterial Blood ◽  
Pulmonary Parenchyma ◽  
Pulmonary Arterial

The resistance to blood flow in the pulmonary circulation of dogs (PVR) increased when their lungs were ventilated with 95–100% oxygen and were perfused with blood that recirculated only through the pulmonary circulation; the systemic circulation was perfused independently. This increase in PVR occurred even when nerves were cut or blocked but was abolished by inhaled isopropylarterenol aerosol. Elevation of intra-alveolar Po2 without increase in pulmonary arterial blood Po2 was sufficient to increase pulmonary vascular resistance. The pulmonary venules or veins were thought to be the likely site of the constriction. These reactions were qualitatively similar to those produced by injection of serotonin or histamine into the pulmonary circulation. The time course of the response and failure to obtain it when the blood was perfused through the remainder of the body before it re-entered the pulmonary circulation are compatible with a theory that high intra-alveolar O2 tension activates a vasoconstrictor material in the pulmonary parenchyma.

Leukotriene end organ antagonists increase pulmonary blood flow in fetal lambs

1985 ◽  
Vol 249 (3) ◽  
pp. H570-H576 ◽  
Author(s):  
S. J. Soifer ◽  
R. D. Loitz ◽  
C. Roman ◽  
M. A. Heymann
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Pulmonary Circulation ◽  
Pulmonary Blood Flow ◽  
Blood Gases ◽  
Physiological Control ◽  
Arterial Blood ◽  
High Pulmonary Vascular Resistance

The factors responsible for maintaining the normally low pulmonary blood flow and high pulmonary vascular resistance in the fetus are not well understood. Since leukotrienes are potent pulmonary vasoconstrictors in many adult animal species, we determined whether leukotrienes were perhaps involved in the control of the fetal pulmonary circulation by studying the effects of putative leukotriene end organ antagonists in two groups of fetal lambs. In six fetal lambs studied at 130-134 days gestation, FPL 55712 increased pulmonary blood flow by 61% (P less than 0.05) and reduced pulmonary vascular resistance by 45% (P less than 0.05). There was a small increase in heart rate but no changes in pulmonary and systemic arterial pressures and systemic arterial blood gases. In six other fetal lambs studied at 130-140 days gestation, FPL 57231 increased pulmonary blood flow by 580% (P less than 0.05) and decreased pulmonary vascular resistance by 87% (P less than 0.05). Pulmonary and systemic arterial pressures decreased (P less than 0.05), and heart rate increased (P less than 0.05). Leukotriene end organ antagonism significantly increases fetal pulmonary blood flow and decreases pulmonary vascular resistance. Leukotrienes may play a role in the physiological control of the fetal pulmonary circulation.

Statics of the respiratory system and growth: an experimental and allometric approach

1981 ◽  
Vol 241 (5) ◽  
pp. R336-R341 ◽  
Author(s):  
J. T. Fisher ◽  
J. P. Mortola
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Chest Wall ◽  
Respiratory System ◽  
Age Groups ◽  
Weight Ratio ◽  
Lung Compliance ◽  
Elastic Recoil ◽  
Lung Weight ◽  
Residual Capacity

Static mechanical properties of the respiratory system have been examined during growth. Static inflation limb pressure-volume curves were obtained in rats and rabbits of three age groups, newborn, 2 wk, and adult. Lung weight-to-body weight ratio (LW/BW) decreased with age. Functional residual capacity (FRC) decreased with age when expressed per unit BW but increased when expressed per unit LW. Elastic recoil pressure of the lung at FRC increased during growth. Respiratory system and chest wall compliance per unit body weight (Crs/BW, Cw/BW) decreased during growth while lung compliance (CL/LW) increased. Examination of the newborn and adult allometric functions with respect to each other, suggests that, in general, changes in respiratory variables during growth are age dependent rather than size dependent. The slopes of these functions during growth tend to be less than the allometric slopes found in either the newborn or adult. In the adult the respiratory system and lung-specific compliances are interspecific constants, whereas chest wall specific compliance decreases with body size. In contrast, all the specific compliances of the newborn are size independent. The allometric ratio of Cw to CL decreases with body size in the adult, whereas this ratio is larger in the newborn and is an interspecific constant.

Sign in / Sign up

Export Citation Format

Share Document