Persistent truncus arteriosus

From Wikipedia, the free encyclopedia

**Persistent Truncus Arteriosus**
*Classification & external resources*
ICD-10	Q 20.0
ICD-9	745.0
OMIM	217095
DiseasesDB	32081
MedlinePlus	001111
eMedicine	ped/2316
MeSH	C14.240.400.929

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.

1 Causes
2 Anatomical changes
3 Clinical manifestations
4 Treatment
5 References
6 External links

[edit] 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] ^[2] 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.^[3] ^[4] ^[5] 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.

[edit] 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

[edit] 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)

[edit] Treatment

Treatment is with neonatal surgical repair.^[6] 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).

[edit] References

^ Kirby ML, Gale TF, and Stewart DE. (1983). "Neural crest cells contribute to normal aorticopulmonary septation.". Science 220 (4061): 1059-61. PMID 6844926.
^ Jiang X, Rowitch DH, Soriano P, McMahon AP, Sucov HM.. (2000). "Fate of the mammalian cardiac neural crest...journal = Development." 127 (8): 1607-16. PMID 10725237.
^ Hutson MR, Kirby ML.. (2003). "Neural crest and cardiovascular development: a 20-year perspective.". Birth Defects Res C Embryo Today. 69 (1): 2-13. PMID 12768653.
^ 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.". Anat. Rec. 260 (3): 279-93. PMID 11066038.
^ Franz T. (1989). "Persistent truncus arteriosus in the Splotch mutant mouse.". Anat. Embryol. (Berlin). 180 (5): 457-64. PMID 2619088.
^ 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.