Persistent truncus arteriosus
| Persistent truncus arteriosus | |
|---|---|
| Specialty | Medical genetics  |
Persistent truncus arteriosus (or Truncus arteriosus) is a rare form of congenital heart disease that presents at birth. It derives its name from the embryological structure also known as the Truncus arteriosus. In the condition, the vessel never properly divides into the pulmonary artery and aorta.
Causes
Most of the time, this defect occurs spontaneously. Genetic disorders, and teratogens (viruses, metabolic imbalance, and industrial or pharmacological agents) have been associated as possible causes. Up to 50% (varies in studies) of cases are associated with chromosome 22q11 deletions. The neural crest, specifically a population known as the cardiac neural crest, directly contributes to the aorticopulmonary septum.[1] Microablation of the cardiac neural crest in developing chick embryos and genetic anomalies affecting this population of cells in rodents results in persistent truncus arteriosus.[2] [3] [4] Numerous perturbations affecting the cardiac neural crest have been associated with persistent truncus arteriosus, some of which include growth factors (fibroblast growth factor 8 and bone mophogenetic protein), transcription factors (T-box, Pax, Nkx2-5, GATA-6,and Forkhead), and gap junction proteins (Connexin).The cardiac neural crest also contributes the smooth muscle of the great arteries.
Anatomical changes
Anatomical changes associated with this disorder includes:
- single artery arising from the two ventricles which gives rise to both the aortic and pulmonary vessels
- abnormal truncal valve
- right sided aortic arch in about 30% of cases (not shown)
- large ventricular septal defect
- pulmonary hypertension
- complete mixing occurring at level of the great vessel
Clinical manifestations
- Cyanosis presents at birth
- Heart failure occurs within weeks
- Systolic ejection murmur is heard at the left sternal border
- Widened pulse pressure
- Bounding arterial pulses
- Loud second heart sound
- Biventricular hypertrophy
- Cardiomegaly
- Increased pulmonary vascularity
- Hypocalcemia (if associated with DiGeorge syndrome)
Treatment
Treatment is with neonatal surgical repair.[5] The ventricular septal defect is closed with a patch. The pulmonary arteries are then detached from the common artery (truncus arteriosus) and connected to the right ventricle using a tube (a conduit or tunnel).
References
- ^ Kirby ML, Gale TF, and Stewart DE. (1983). "Neural crest cells contribute to normal aorticopulmonary septation". Science. 220 (4061): 1059–61. PMID 6844926.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Hutson MR, Kirby ML.. (2003). "Neural crest and cardiovascular development: a 20-year perspective.journal = Birth Defects Res C Embryo Today". 69 (1): 2–13. PMID 12768653.
{{cite journal}}: Cite journal requires|journal=(help) - ^ Waller BR 3rd, McQuinn T, Phelps AL, Markwald RR, Lo CW, Thompson RP, Wessels A. (2000). "Conotruncal anomalies in the trisomy 16 mouse: an immunohistochemical analysis with emphasis on the involvement of the neural crest.journal = Anat. Rec". 260 (3): 279–93. PMID 11066038.
{{cite journal}}: Cite journal requires|journal=(help)CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link) - ^ Franz T. (1989). "Persistent truncus arteriosus in the Splotch mutant mouse..journal = Anat. Embryol. (Berlin)". 180 (5): 457–64. PMID 2619088.
{{cite journal}}: Cite journal requires|journal=(help) - ^ Rodefeld M, Hanley F. "Neonatal truncus arteriosus repair: surgical techniques and clinical management". Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 5: 212–7. PMID 11994881.
External links
Truncus Arteriosus Cincinnati Children's Medical Center
Truncus Arteriosus information from Seattle Children's Hospital Heart Center
- 00755 at CHORUS
