|
|
| Line 22: |
Line 22: |
| {{Editor Join}} | | {{Editor Join}} |
|
| |
|
| ==Overview== | | ==[[Persistent truncus arteriosus overview|Overview]]== |
| '''Persistent truncus arteriosus''' (or '''Truncus arteriosus''') is a rare form of [[congenital heart disease]] that presents at birth. In this condition, the [[embryological]] structure known as the [[truncus arteriosus (embryology)|truncus arteriosus]] never properly divides into the [[pulmonary artery]] and [[aorta]].
| |
|
| |
|
| ==Classification== | | ==[[Persistent truncus arteriosus classification|Classification]]== |
| The most well-known classification was the fourfold system developed by Collett and Edwards in 1949.<ref>Collett RW, Edwards JE: Persistent truncus arteriosus: a classification according to anatomic types. Surg Clin North Am 1949; 29: 1245-70.</ref> Collett/Edwards Types I, II, and III are distinguished by the branching pattern of the pulmonary arteries:<ref>{{cite web |url=http://www.merck.com/mmpe/sec19/ch287/ch287k.html |title=Persistent Truncus Arteriosus: Congenital Cardiovascular Anomalies: Merck Manual Professional |accessdate=2007-11-04 |format= |work=}}</ref><ref name="McElhinney">{{cite web |url=http://www.emedicine.com/ped/topic2316.htm |title=eMedicine - Truncus Arteriosus : Article by Doff McElhinney, MD |accessdate=2007-11-04 |format= |work=}}</ref>
| |
|
| |
|
| * Type I: truncus -> one pulmonary artery -> two lateral pulmonary arteries
| | ==[[Persistent truncus arteriosus causes|Causes]]== |
| * Type II: truncus -> two posterior/posterolateral pulmonary arteries
| |
| * Type III: truncus -> two lateral pulmonary arteries
| |
|
| |
|
| The "Type IV" proposed in 1949 is no longer considered a form of PTA by most modern sources.<ref name="McElhinney"> </ref>
| | ==[[Persistent truncus arteriosus causes anatomical changes|Anatomical changes]]== |
|
| |
|
| Another well-known classification was defined by Van Praaghs in 1965.<ref name="pmid5828135">{{cite journal |author=Van Praagh R, Van Praagh S |title=The anatomy of common aorticopulmonary trunk (truncus arteriosus communis) and its embryologic implications. A study of 57 necropsy cases |journal=Am. J. Cardiol. |volume=16 |issue=3 |pages=406–25 |year=1965 |pmid=5828135 |doi=}}</ref><ref name="McElhinney"> </ref>
| | ==[[Persistent truncus arteriosus clinical manifestations|Clinical manifestations]]== |
| | |
| ==Causes==
| |
| Most of the time, this defect occurs spontaneously. [[Genetic disorders]], and [[teratogen]]s (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 22]]q11 deletions. The [[neural crest]], specifically a population known as the cardiac neural crest, directly contributes to the [[aorticopulmonary septum]].<ref>{{cite journal | author = Kirby ML, Gale TF, and Stewart DE. | title = Neural crest cells contribute to normal aorticopulmonary septation. | journal = Science | volume = 220 | issue =4061 | pages = 1059-61 | year =1983 | id = PMID 6844926}}</ref> <ref>{{cite journal | author = Jiang X, Rowitch DH, Soriano P, McMahon AP, Sucov HM..| title = Fate of the mammalian cardiac neural crest...journal = Development. | volume = 127| issue =8| pages = 1607-16 | year =2000 | id = PMID 10725237}}</ref>
| |
| | |
| 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.<ref>{{cite journal | author = Hutson MR, Kirby ML.. | title = Neural crest and cardiovascular development: a 20-year perspective. | journal = Birth Defects Res C Embryo Today. | volume = 69 | issue =1| pages = 2-13 | year =2003 | id = PMID 12768653}}</ref> <ref>{{cite journal | author = Waller BR 3rd, McQuinn T, Phelps AL, Markwald RR, Lo CW, Thompson RP, Wessels A.| title = Conotruncal anomalies in the trisomy 16 mouse: an immunohistochemical analysis with emphasis on the involvement of the neural crest. | journal = Anat. Rec. | volume = 260 | issue =3| pages = 279-93 | year =2000 | id = PMID 11066038 }}</ref> <ref>{{cite journal | author = Franz T.| title = Persistent truncus arteriosus in the Splotch mutant mouse. | journal = Anat. Embryol. (Berlin). | volume = 180 | issue =5| pages = 457-64 | year =1989 | id = PMID 2619088 }}</ref>
| |
| | |
| Numerous perturbations affecting the cardiac neural crest have been associated with persistent truncus arteriosus, some of which include [[growth factor]]s ([[fibroblast growth factor 8]] and [[bone morphogenetic protein]]), [[transcription factor]]s ([[T-box]], [[Pax genes|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 [[ventricle (heart)|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]])
| |
|
| |
|
| ==Diagnosis== | | ==Diagnosis== |
| | [[Persistent truncus arteriosus echocardiography|Echocardiography]] |
|
| |
|
| ===Echocardiography=== | | ==[[Persistent truncus arteriosus treatment|Treatment]]== |
| | |
| *Truncus Arteriosus Type I 1
| |
| <googlevideo>8970669383266720423&hl=en</googlevideo>
| |
| *Truncus Arteriosus Type I 2
| |
| <googlevideo>564681477766752717&hl=en</googlevideo>
| |
| *Truncus Arteriosus Type I 3
| |
| <googlevideo>564681477766752717&hl=en</googlevideo>
| |
| *Truncus Arteriosus Type I 4
| |
| <googlevideo>-3202146762215926147&hl=en</googlevideo>
| |
| *Truncus Arteriosus Type I 5
| |
| <googlevideo>5568593693292079875&hl=en</googlevideo>
| |
| *Truncus Arteriosus Type I 6
| |
| <googlevideo>-1383871098920679580&hl=en</googlevideo>
| |
| | |
| ==Treatment==
| |
| Treatment is with neonatal surgical repair.<ref>{{cite journal | author = Rodefeld M, Hanley F | title = Neonatal truncus arteriosus repair: surgical techniques and clinical management. | journal = Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu | volume = 5 | issue = | pages = 212-7 | year = | id = PMID 11994881}}</ref> The [[ventricular septal defect]] is closed with a patch. The [[pulmonary artery|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== | | ==References== |
