The developing bronchial arteries in a fetus of the twelfth week

Pseudomonas aeruginosa isolation is an important predictor for recurrent hemoptysis after bronchial artery embolization in patients with idiopathic bronchiectasis: a multicenter cohort study

BACKGROUND

Nearly half of bronchiectasis patients receiving bronchial artery embolization (BAE) still have recurrent hemoptysis, which may be life-threatening. Worse still, the underlying risk factors of recurrence remain unknown.

METHODS

A retrospective cohort was conducted of patients with idiopathic bronchiectasis who received BAE from 2015 to 2019 at eight centers. Patients were followed up for at least 24 months post BAE. Based on the outcomes of recurrent hemoptysis and recurrent severe hemoptysis, a Cox regression model was used to identify risk factors for recurrence.

RESULTS

A total of 588 individuals were included. The median follow-up period was 34.0 months (interquartile range: 24.3-53.3 months). The 1-month, 1-year, 2-year, and 5-year cumulative recurrent hemoptysis-free rates were 87.2%, 67.5%, 57.6%, and 49.4%, respectively. The following factors were relative to recurrent hemoptysis: 24-h sputum volume (hazard ratio [HR] = 1.99 [95% confidence interval [95% CI]: 1.25-3.15, p = 0.015]), isolation of Pseudomonas aeruginosa (HR = 1.50 [95% CI: 1.13-2.00, p = 0.003]), extensive bronchiectasis (HR = 2.00 [95% CI: 1.29-3.09, p = 0.002]), and aberrant bronchial arteries (AbBAs) (HR = 1.45 [95% CI: 1.09-1.93, p = 0.014]). The area under the receiver operating characteristic curve of the nomogram was 0.728 [95% CI: 0.688-0.769].

CONCLUSIONS

Isolation of Pseudomonas aeruginosa is an important independent predictor of recurrent hemoptysis. The clearance of Pseudomonas aeruginosa might effectively reduce the hemoptysis recurrence rate.

Tracheobronchial arterial variants of vertebral artery origin and bronchovertebral arterial anastomoses

PURPOSE

This report describes a series of angiographic observations of tracheobronchial arterial variants and discusses their clinical implications.

METHODS

The angiographic features of eleven aberrant tracheal or bronchial arteries are reported, including four variants originating from the vertebral artery and two cases of bronchovertebral anastomosis. An additional observation of thyrothymic artery illustrates the discussion of the mechanisms involved in the development of these variants.

RESULTS

Tracheobronchial arterial variants are predominantly left-sided variants (9 out of 11). They are linked to dominant paratracheal arterial connections, particularly the lateral longitudinal anastomosis. Unusual bronchial arteries of vertebral origin show a strong association with aberrant left vertebral arteries of aortic or proximal subclavian origin.

CONCLUSION

This report presents a spectrum of tracheo-broncho-vertebral variations and emphasizes the role of previously described paratracheal arterial anastomoses in their formation. These variants can play a critical role during hemoptysis embolotherapy, either as an occult source of hemorrhage or as a risk factor for devastating complications.

Spatial relationships of the bronchial arteries to the left recurrent laryngeal nerve in the sub-aortic arch area

PURPOSE

To safely perform lymphadenectomy in the sub-aortic arch area during esophagectomy for esophageal cancer, we investigated the spatial relationships between the bronchial arteries (BAs) and the left recurrent laryngeal nerve (LRLN).

METHODS

For this macro-anatomical study, 72 cadavers were used.

RESULTS

Of the 195 dissected BAs, 15 (7.7%) arteries ran dorsally across the LRLN. Such a running pattern of the BA was found in 15 (20.8%) of the 72 cadavers. Fourteen (93.3%) of the 15 arteries ran anteriorly along the left side of the esophagus, and 13 (86.7%) passed further to the lateral side of the left main bronchus to reach the ventral surface of the tracheobronchus; we named this running pattern "Type III". Of the 51 arteries with the Type III pattern, 25.5% ran across the dorsal side of the LRLN.

CONCLUSION

Approximately 20% of the cadavers had BAs running dorsally to the LRLN in the sub-aortic arch area. Most of these arteries had the Type III pattern. One-quarter of the BAs with the Type III pattern showed this running pattern. Care must be practiced to safely perform lymphadenectomy for esophageal cancer in patients with Type III BAs.

A case of unusual configuration of the right bronchial arteries combined with cryptogenic severe bilateral hypertrophy

Bronchial arteries commonly originate from thoracic aorta between T5 and T6. Ectopic origins from aortic arch, supraortic trunks and their branches, coronary arteries, and even abdominal aorta have been described in the literature. In some circumstances, such as pulmonary artery malformations, chronic embolism, or inflammatory diseases of the lung, the bronchial arteries become hypertrophied and eventually could be the only supply of pulmonary circulation. Here, we describe a case of an elderly man who presented an unusual pattern of bronchial arteries of the right lung combined with severe bilateral hypertrophy of bronchial vessels. In the right side, one bronchial artery originated from the descendent aorta and anastomosed with a branch descending from the thyrocervical trunk, which, in turn, received in its path an anastomosis from the superior intercostal artery. The right lung also received a second bronchial artery that originated from the internal thoracic artery. This arterial configuration could be explained by the persistence of precostal longitudinal anastomoses during the embrionary development. Left bronchial arteries presented an orthotopic origin from the descending aorta. Arteries of both sides were very hypertrophic and tortuous resembling major aortopulmonary collateral arteries described in patients with pulmonary atresia. Hypertrophy was more pronounced in the right lung with some segments presenting a lumen diameter of 10 mm. No cardiac or vascular malformations that could explain the hypertrophy of bronchial arteries were observed. In contrast, both lungs showed clear signs of chronic inflammation and fibrosis that could be the cause of bronchial artery hypertrophy.

Antenatal hypoxia and pulmonary vascular function and remodeling

This review provides evidence that antenatal hypoxia, which represents a significant and worldwide problem, causes prenatal programming of the lung. A general overview of lung development is provided along with some background regarding transcriptional and signaling systems of the lung. The review illustrates that antenatal hypoxic stress can induce a continuum of responses depending on the species examined. Fetuses and newborns of certain species and specific human populations are well acclimated to antenatal hypoxia. However, antenatal hypoxia causes pulmonary vascular disease in fetuses and newborns of most mammalian species and humans. Disease can range from mild pulmonary hypertension, to severe vascular remodeling and dangerous elevations in pressure. The timing, length, and magnitude of the intrauterine hypoxic stress are important to disease development, however there is also a genetic-environmental relationship that is not yet completely understood. Determining the origins of pulmonary vascular remodeling and pulmonary hypertension and their associated effects is a challenging task, but is necessary in order to develop targeted therapies for pulmonary hypertension in the newborn due to antenatal hypoxia that can both treat the symptoms and curtail or reverse disease progression.

Rare multiple combined anomaly of the vertebral vessels and bronchial artery

Reported herein is a rare case of multiple vascular anomalies involving the vertebral vessels and the bronchial artery. In the present case the vertebral artery, which normally originates from the subclavian artery, arose directly from the cranial side of the aortic arch, just between the left common carotid and subclavian artery. Furthermore, the bilateral entry of the vertebral artery deviated to the upper level of the transverse foramen of the cervical vertebrae (C5). In addition, the left vertebral vein went through the transverse canal via the 5th and 7th transverse foramen, and drained into the left venous angle. Another conspicuous variation observed in this cadaver was the bronchial artery stemming from the left subclavian artery. This phenotype is an additional branch of bronchial arteries, which in normal cases arises from the descending aorta. These two anomalies could be explained by the deviation of the anlage for the left subclavian artery. The present report should be of interest for the clinician with regard to vascular anomalies in the neck and thoracic region, and may give insight into elucidating the developmental mechanism of angiogenesis.

Pulmonary Vascular Disease

The pulmonary vasculature is an anatomic compartment that is frequently overlooked in the histologic review of lung biopsy samples, other than those obtained specifically to assess pulmonary vascular disease.1 Though often of a nonspecific nature, the histologic pattern of vascular remodeling may at times suggest its underlying pathogenesis and provide clues to the cause of pulmonary hypertension.2 Disproportionately severe vascular pathology may further indicate alternate disease processes, such as congestive heart failure or thromboemboli, contributing to the patient’s overall respiratory condition.

Pulmonary pathology

Common causes of neonatal respiratory distress include meconium aspiration, pneumonia, persistent pulmonary hypertension of the newborn, pneumothorax and cystic adenomatoid malformation. Genomics and proteomics have enabled the recent recognition of several additional disorders that lead to neonatal death from respiratory disease. These are broadly classified as disorders of lung homeostasis and have pathological features of proteinosis, interstitial pneumonitis or lipidosis. These pathological changes result from inherited disorders of surfactant proteins or granulocyte-macrophage colony stimulating factor. Abnormal lung vascular development is the basis for another cause of fatal neonatal respiratory distress, alveolar capillary dysplasia with or without associated misalignment of veins. Diagnosis of these genetically transmitted disorders is important because of the serious implications for future siblings. There is also a critical need for establishing an archival tissue bank to permit future molecular biological studies.

Systemic-to-pulmonary blood supply in Tetralogy of Fallot with pulmonary atresia

Tetralogy of Fallot with pulmonary atresia is one of the most challenging congenital cardiac malformations, for the morphologist, cardiologist and surgeon alike. Much of the difficulty in this lesion concerns the nature and development of pulmonary arterial supply, and the manner in which complete segmental supply to the lungs can be successfully restored or maintained. In this review, we discuss the anatomy and nomenclature of the lesion, emphasising the variability that can occur in pulmonary arterial anatomy, particularly in the presence of systemic-to-pulmonary collateral arteries. We speculate on the likely embryologic origins of these connections. Then by means of anatomic-clinical correlations, we emphasise the diagnostic approach to delineating the origin and extent of the pulmonary vasculature.

Embryonic and early fetal development of human lung vasculature and its functional implications

Recently, we have identified in the mouse three processes involved in the early development of pulmonary vasculature: angiogenesis for branching of central vessels, vasculogenesis (lakes in the mesenchyme) for peripheral vessels, and a lytic process to establish luminal connection between the two. We have established that these three processes also operate in the human by studying serial sections of human embryos and early fetuses. Vascular lakes of hematopoietic cells appear at stage 13, i.e., 4+ weeks gestational age (GA), the first intrapulmonary vascular structure to appear. At stage 20 (50.5 days GA), a venous network with luminal connections to central pulmonary veins (PV) is present. Airways have not yet reached these regions of lung. At its first intrapulmonary appearance, the pulmonary artery (PA) is small and thick walled: it runs with the airway but its branching is slower, so many peripheral airways are not accompanied by a PA branch. By contrast, the PV has a peripheral patent network well before the PA. In the pseudoglandular phase, airway branching continues, and the PA catches up so that small PA branches are found with all airways. Later in this phase small nonmuscular vessels lie in the mesenchyme close to airway epithelium. By the early canalicular phase and the age of viability, continuity between pulmonary artery and the peripheral capillary network must be established. In a 10-week fetus several structures suggesting a breakthrough site were seen. Air-blood barrier structure is first seen at 19 weeks. Thus in the lung, the PA and PV are dissociated in their timing and pattern of branching. Early veins are present diffusely through the mesenchyme and establish central luminal connection to the main pulmonary vein before airway or artery are present at this level.

Systemic to pulmonary collaterals in very low birth weight infants: color doppler detection of systemic to pulmonary connections during neonatal and early infancy period

OBJECTIVE

Angiographic visualization of systemic to pulmonary collaterals (SPC) has been documented in premature infants needing prolonged ventilatory support. Noninvasive identification of such communications in premature infants was reported recently. The purpose of this study was to describe: 1) incidence, 2) clinical findings and implications, and 3) short-term follow-up of SPC diagnosed by echocardiography in very low birth weight (VLBW) infants admitted to the neonatal intensive care unit.

METHODS

From December 1, 1994 to August 31, 1996, 196 infants with birth weight <1500 g were admitted to the neonatal intensive care unit; 133 of them received serial echocardiographic evaluations at 1 to 2 days, at 2 weeks, and at 1, 2, and 3 months of life. Follow-up echocardiograms were scheduled at 6 months and 1 year of age for patients with SPC persisting at 3 months of age.

RESULTS

SPC were demonstrated in 88 patients (66%) at 1 to 90 days of life (mean 28 days). In most cases, the SPC originated at the distal aortic arch or the proximal descending aorta. Ten patients (11%) were treated for congestive heart failure. The symptoms improved and anticongestive therapy was discontinued in 9. One patient with persistent congestive heart failure underwent therapeutic cardiac catheterization and 1 prominent SPC was embolized.

CONCLUSIONS

The incidence of SPC in VLBW infants is much higher than previously reported. We postulate that SPC are bronchopulmonary communications that enlarge and/or proliferate in response to a given stimulus. These communications are associated with increased time on positive pressure ventilation and length of stay in the hospital. SPC may lead to pulmonary edema and should be searched for in VLBW infants with a more complicated course. Echocardiographic examination with color Doppler performed in premature infants to evaluate left to right shunts should include careful search for systemic to pulmonary collaterals.echocardiography, systemic to pulmonary collaterals, aortopulmonary collaterals, prematurity, pulmonary edema.

Bronchial circulation in the marsupial opossum, Didelphis marsupialis

This study characterizes the existence of a bronchial circulation in a marsupial, an animal which does not undergo placental development and does not have a ductus arteriosus. Direct perfusion of the lung by the pulmonary vasculature during the fetal development of opossums may occur, potentially eliminating the need for a bronchial circulation. We used radio- and fluorescent-labeled microspheres in conjunction with postmortem intravascular casting to determine if opossums have a systemic (bronchial) blood supply to the lung (n = 9). Gross postmortem examination of the intravascular casts showed a well-developed common bronchial artery. The histological distribution pattern of fluorescent microspheres was primarily to the airways. A few fluorescent microspheres were observed in the alveolar capillaries, indicating that a precapillary bronchial-to-pulmonary anastomosis exists in the opossum. Using the reference flow technique, total bronchial blood flow to the left lung averaged 0.95 +/- 0.58 SE ml/min. The presence of a bronchial circulation in the opossum suggests that it is more than a vestigial structure from embryonic development, potentially supporting its functional importance for carrying nutrients to the airway.

Evaluation and management of hemoptysis in infants and children. A report of nine cases

Hemoptysis is an occasional complication of adult pulmonary disease and is rare in children. The most common causes in adults are infection, bronchiectasis, pulmonary neoplasm, cystic fibrosis, pulmonary infarct, and trauma; in children the most common causes are infection and congenital abnormalities of the cardiopulmonary vasculature. Nine cases of hemoptysis in seven infants and two children will be presented. Two cases were fatal, thus illustrating the importance of rapid and definitive therapy early in the course. One of the fatal cases is the first case report in the otolaryngological literature of fatal hemoptysis in the newborn as a result of vascular anomalies associated with an absent left pulmonary artery. Eight cases of various causes, including small vessel vascular abnormality, trauma, recurrent pulmonary infection, and laryngotracheal papilloma, are discussed. The literature is reviewed, embryology is discussed, and a mechanism of death is theorized for the patient with the congenital vessel anomaly. Management considerations for hemoptysis in infants and children are discussed.

A common bronchial arterial trunk arising from a left subclavian artery: a rare anatomic variant

The origin of the bronchial arteries is very variable. An exceptional case is reported of a common bronchial arterial trunk arising from a left subclavian artery discovered incidentally during angiography in a patient without any pulmonary disease. An embryologic explanation is proposed for this anatomic variant.

Development of the pharyngeal arch system related to the pulmonary and bronchial vessels in the avian embryo. With a concept on systemic-pulmonary collateral artery formation

BACKGROUND

The literature is ambiguous as to the question of the developmental background of systemic-pulmonary collateral arteries. These are found in combination with various congenital heart malformations such as pulmonary atresia. From a clinical point of view, it is of interest to know whether we are dealing with the persistence of transient embryological vessels such as ventral segmental arteries or parts of pharyngeal arch arteries or with the prenatal or postnatal recruitment of the bronchial vasculature that normally supplies the lung. This study of the embryology of the extrapulmonary and intrapulmonary vasculature aims at a better understanding of the variations in origin, course, branching pattern, and histology of collateral arteries.

METHODS AND RESULTS

Serial sections of quail embryos ranging between stage HH11 and stage HH28 were incubated with a monoclonal antibody (alpha MB1) against endothelial cells and their precursors. Additional series of chick embryos were injected with india ink to study the lumenized vascular patterns. A splanchnic plexus consisting of endothelial cells and precursors is present around the foregut before the lung buds develop. This plexus expands and gives rise to the pharyngeal arch arteries, the ventral pharyngeal veins, the pulmonary vessels, and the bronchial vessels, including the intrapulmonary vessel network. During two subsequent periods, the splanchnic plexus is transiently connected to the systemic arteries and veins. The bronchial arteries and veins develop in the second period from these transient vessels. The expansion and extension of the splanchnic plexus to many organs during the formation of the bronchial vessels explains the varying course and branching pattern of the bronchial vasculature.

CONCLUSIONS

These results show that we are not dealing with two or more individual vascular systems that contribute to the developing vessels of the lungs but with one vascular plexus that normally gives rise to the pulmonary and bronchial vasculature but has the potential to give rise to other systemic-pulmonary connections.

Enlarged bronchial arteries after early repair of transposition of the great arteries

OBJECTIVES

This study was undertaken to define the incidence of enlarged bronchial arteries after early surgical repair of transposition of the great arteries by the arterial switch operation, and to report the results of catheter-directed therapy in five patients.

BACKGROUND

Pathologic and angiographic studies have demonstrated enlarged bronchial arteries in patients with transposition of the great arteries.

METHODS

A subjective 4-point scale was used to grade postoperative angiograms performed in 119 patients at our institution between January 1983 and December 1991. Grades 0 and 1 were designated if there was no opacification of the pulmonary arteries or veins, whereas grades 2 and 3 were assigned if there was such opacification. The median age at repair was 8 days (range 1 day to 13 months) and the median age at catheterization was 11.2 months (range 3.6 to 58.5). An intact ventricular septum was present in 84 (71%) of 119 patients.

RESULTS

Significantly increased bronchial flow (grade 2 or 3) was present in 55 (46%) of 119 patients. Age at repair, age at catheterization and interval between repair and catheterization were not associated with significantly increased bronchial flow; however, an intact ventricular septum was weakly associated with increased flow (p = 0.04). Coil embolization was performed in five patients with complete occlusion of the vessels and no significant complications.

CONCLUSIONS

Abnormally enlarged bronchial arteries are frequently identified at postoperative catheterization despite early repair and may explain continuous murmurs or persistent cardiomegaly in patients with otherwise normal noninvasive findings. When clinically indicated, catheter-directed therapy can be performed with good results.

The special status of the pulmonary arch artery in the branchial arch system of the rat

A renewed study of the development of the branchial arch system was essential in view of the special morphologic characteristics of the ductus arteriosus, which derives from the pulmonary arch artery or sixth branchial arch artery. In congenital heart disease certain aorto-pulmonary collateral arteries have a marked histological similarity to the ductus arteriosus. To gain a better insight into the development of these vessels, 27 rat embryos, with the number of somites ranging between 19 and 41, were studied. Most embryos were collected after shortterm in vitro-culture, allowing precise staging of age and development. The vascular system of these embryos was injected with Indian ink, to enable easy recognition of even the smallest endothelium-lined vessels. The embryos were serially sectioned (3-5 microns) and reconstructed using a graphic method. The results show that the pulmonary arch artery differs from the other arch arteries in that it is the most cranial vessel of a system of ventral splanchnic arteries, which connects the pulmonary plexus with the dorsal aortae at an early stage. With the exception of the pulmonary arch artery, these connections are transient. The pulmonary arteries develop from the remaining parts of the plexus. It is argued that these connections can persist in the human as aorto-pulmonary collaterals, in certain cases with abnormalities in the pulmonary part of the cardiac outflow tract.

Pulmonary artery agenesis presenting as massive hemoptysis--a case report

Massive hemoptysis is the expectoration of approximately 600 ml of blood in twenty-four hours. Major causes of massive hemoptysis are tuberculosis, bronchiectasis, pulmonary neoplasm, fungus ball, bronchial adenomas, lung abscess, intrabronchial rupture of an aortic aneurysm, cystic fibrosis, pulmonary infarction, and pulmonary trauma. Other, less common causes include Goodpasture's syndrome, broncholiths, pulmonary varix, A-V malformation, and bleeding disorders. Agenesis of the pulmonary artery usually occurs in association with congenital cardiac anomalies, and isolated unilateral absence of the pulmonary artery is uncommon. About 10% of the patients with pulmonary artery agenesis develop inconsequential hemoptysis, but massive hemoptysis is a very rare complication of this anomaly. The following is a case report of a twenty-nine-year-old man with agenesis of the left pulmonary artery, who presented with massive hemoptysis requiring embolization and, eventually, pneumonectomy.

Unusual vascular anomalies causing persistent pulmonary hypertension in a newborn

A unique case of pulmonary vascular anomalies causing persistent pulmonary hypertension in a newborn is described. The child died 3 days after birth. Necropsy revealed marked hypoplasia of the right and left pulmonary arteries with a normal main pulmonary artery, patent ductus arteriosus, bilateral systemic arteries to the lungs from the abdominal aorta, and partial anomalous pulmonary venous connection. Quantitative morphometric techniques demonstrated slight abnormalities of alveolar development and severe arterial medial hypertrophy with abnormal extension of muscle into small peripheral arteries. Bronchopulmonary development appeared relatively normal in spite of the vascular abnormalities.

Quantitative structural study of pulmonary circulation in the newborn with pulmonary atresia

The lungs of eight newborn infants who had died from pulmonary atresia were studied by quantitative morphometric techniques. It was established for the first time that the abnormal pattern of blood flow through the heart and great vessels in a fetus with pulmonary atresia is associated with impaired lung development as shown by arteries that are too few, too small, and with an abnormally thin muscle coat, although the distribution of muscle along the arterial pathway is normal. Differences between the cases in the degree of impairment of lung development could be detected and related to the degree of reduction in pressure and flow before birth in the individual case. Although blood flow through the pulmonary circulation is small before birth lung development seems sensitive to any further reduction.

Unilateral congenital dysplasia of lung associated with vascular anomalies

Hislop, A., Sanderson, M., and Reid, L. (1973).Thorax, 28, 435-441. Unilateral congenital dysplasia of lung associated with vascular anomalies. In three cases of unilateral lung dysplasia the structural changes have been analysed quantitatively to throw light on the nature of the anomaly and stage of its appearance. In one case the pulmonary artery was hypoplastic and the systemic supply normal but increased, suggesting onset in late intrauterine life or early childhood: in the other two cases the blood supply was only systemic, from both normal and abnormal arteries, suggesting onset in the early weeks of intrauterine development. Airway development was consistent with this interpretation. All cases had additional signs of maldevelopment of mesodermal tissue. The origin of the various types of systemic artery is discussed.