Aberrant bronchi and cardiovascular anomalies

Abstract

In an investigation of malformation associations in consecutive perinatal autopsies, 4 infants were identified as having a displaced or supernumerary bronchus. Each had a different type of bronchial abnormality and 3 had congenital heart defects and other malformations. Review of the literature found 38 other cases of aberrant bronchi with additional defects, especially cardiovascular or costovertebral anomalies. Structural cardiac defects were more common in patients with super-numerary tracheal bronchi (67%) than in those with displaced tracheal bronchi (27%) or bronchoesophageal connections (23%). There was also a strong negative association (P = 0.01) of cardiovascular and costovertebral defects unless multiple anomalies were present. The combinations of anomalies seen appear to reflect relatively specific developmental field defects affected both by the spatial relationships of organs near the developing foregut and by temporal sequence. Recognition of these patterns has clinical and embryological importance. Aberrant bronchi should be considered when children with cardiac defects or multiple anomalies such as the VACTERL association have unexplained respiratory symptoms and surgeons planning to treat such bronchial abnormalities should be aware of the high frequency of abnormal vessels in these cases.

Signaling through BMP receptors promotes respiratory identity in the foregut via repression of Sox2

“…We note that the trachea agenesis phenotype resembles human birth defects that are highly lethal. In addition, a similar supernumerary bronchi phenotype in humans is associated with frequent respiratory infections (Brunner and van Bokhoven, 2005;Desir and Ghaye, 2009;Evans, 1990). Our findings therefore provide mechanistic insights into the etiology of these diseases.…”

“…Mutations in Sox2 and chromosomal deletions spanning Nog have been identified in patients with esophageal atresia (Que et al, 2006), suggesting that precise regulation of BMP and its downstream genes is likely essential for proper foregut patterning in human. Just as Bmpr1a;b mutant mice display ectopic buds, individuals with ectopic or mislocated bronchial branches have been described (Desir and Ghaye, 2009;Evans, 1990;Panigada et al, 2009). The frequency of these aberrations is unknown, as individuals with them may be asymptomatic for respiratory ailments.…”

Association Between Tetralogy of Fallot and Tracheobronchial Branching Abnormalities: A New Clue for Pathogenesis?

“…In our experience, we noticed an increased frequency of tracheobronchial branching abnormalities (TBAs) in patients with ToF, especially of the left eparterial bronchus, a rare TBA of the left upper lobe. Higher frequency of right‐sided TBAs in children with congenital heart disease has been reported by a few researchers . However, to the best of our knowledge, an association between TBAs and ToF has not been reported.…”

Bronchus Cardiacus Accessorius Dexter

“…Its occurrence has been described also in both twins [8,9]. The mechanism of its formation is studied nowadays following the embryonic development of the lungs [12,13]. Namely, during 4-6th weeks of the intrauterine life, a primordial bronchus called lobulus infracardiacus grows out from the right bronchial anlage of the embryo, which disappears at later stages of development [12].…”