Download Double Inlet Ventricle

Double Inlet Ventricle
Seoul National University Hospital
Department of Thoracic & Cardiovascular Surgery
Double Inlet Ventricle
1. Definition
A congenital cardiac malformation in which both atria
connect to only one ventricular chamber by either two separate
atrioventricular valves or a common AV valve
Single ventricle, univentricular AV connection
2. History
Holmes
: Solitary ventricular chamber in 1824
Rokitansky : Double inlet left ventricle in 1875
Taussig
: Single ventricle in 1939
Van Praagh : Clear definition of this entity in 1964
Muller & Damman ; PA banding for single ventricle in 1952
Mayo Clinic : Septation on single ventricle
Double Inlet Ventricle
Pathophysiology
• A single functional ventricle receives both systemic
and pulmonary venous return via right- & left-sided
atrioventricular valves or a single common valve,
resulting in mixing of oxygenated & deoxygenated
blood and , hence, systemic arterial hypoxemia.
• This defect is also associated with excessive or
inadequate pulmonary blood flow, depending on
whether there is obstruction to pulmonary flow
(e.g., pulmonary stenosis/atresia).
Spectrum of AV Malalignment
Double Inlet Ventricle
Morphology
• Ventricular mass
Main( dominant) chamber, Nondominant chamber,
Bulboventricular foramen
• Atria
Any types of atrial situs can be present
• Atrioventricular connection
Usually two AV valves, Valves or common valve
overriding in 20 % of cases
• Ventriculoarterial connection
• Conduction tissue
• Coronary arteries
Types of Double Inlet Ventricle
1. Double inlet LV with left-sided rudimentary RV & discordant
ventriculoarterial connection {S,L,L}
2. Double inlet LV with right-sided rudimentary RV & concordant
ventriculoarterial connection ({S,D,S} : Holme’s heart)
3. Double inlet LV with right-sided rudimentary RV & discordant
ventriculoarterial connection {S,D,D}
4. Double inlet and double outlet LV
5. Double inlet and double outlet RV
6. Double inlet RV with concordant ventriculoarterial connection
7. Solitary ventricle of intermediate morphology
Frequent Double Inlet Ventricle
1 DILV with left rudimentary RV & discordant VA connection {S,L,L}
* Most frequent type (50%)
* Restrictive VSD is frequent : subaortic stenosis, CoA, IAA
* Subpulmonic obstruction
: favorable clinical course
* Frequent stenosis or hypoplasia of AV valve
2 DILV with right rudimentary RV & concordant VA connection {S,D,L}
* Less than 10%
* Usual atrial arrangement
* Frequent right AV valve straddling and overriding
* Usually restrictive VSD
3 Double inlet and double outlet right ventricle
* About 5%
* Usual atrial arrangement, or right isomerism
* PS or PA and TAPVR
Double Inlet Left Ventricle
(SDD)
Double Inlet Left Ventricle
(SLL)
DILV (1)
Morphologic LV
DILV (2)
Morphologic RV
Double Inlet Ventricle
 Connections
* Atrioventricular
concordant
discordant : frequent
ambiguous
* Ventriculoarterial
concordant
discordant : frequent (60-80%)
Double Inlet Ventricle
Associated cardiac anomalies
1
2
3
4
5
Subaortic stenosis (restrictive BVF or VSD)
Pulmonary stenosis (subpulmonary stenosis)
Pulmonary atresia
Patent ductus arteriosus
AV valve stenosis, hypoplasia, straddling,
overriding
6 IAA, CoA, aortic arch hypoplasia
Double Inlet Ventricle
Natural History
• Incidence
3% of CHD
M : F = 2.5 : 1
• Estimated overall survival without treatment
1) Not entirely accurate
2) Less risk of death during neonatal & infant period
3) 57%, 45% remain alive at 1, 5 years
4) Acidosis & low cardiac output is a severe risk factor
5) Systemic outflow obstruction is strong risk factor
Clinical Features & Diagnosis
1. Clinical features are governed by the morphology &
associated lesions
2. Variable according to following anomalies
(TAPVR, PS, PA, subaortic obstruction, CoA, IAA,
unobstructed pulmonary blood flow)
3. Pulmonary blood flow
1/3
: decreased
2/3
: increased
small % : balanced
4. Electrocardiogram & chest radiography
5. Echocardiography & cineangiography
6. CT angiography & MRA
Systemic Outflow Obstruction
Initial Palliation
• Pulmonary artery banding & CoA repair
• Norwood & DKS type operation
• Palliative arterial switch operation
• Alternative surgical approaches ;
PAB, CoA repair, enlargement of BVF,
Apical LV-aortic conduit, Transplantation
Systemic Outflow Obstruction
• Surgical treatment of subaortic stenosis in functional single ventricle
Operative Management
Techniques
1 Septation
* At any age or in patients with increased PVR, or after
palliative procedure
* Usually in {S,L,L} type single ventricle
* Some of {S,L,D} with arterial switch operation (without PS)
* High mortality and complications
(complete heart block, residual VSD, A-V valve regurgitation,
sudden death)
2 Fontan operation
* Usually done around 2 years old
* After banding or systemic-pulmonary artery shunt
Fontan Operation
• Right AV valve may be closed as part of Fontan-type
repair in double inlet left ventricle
Septation Operation
• Septation is performed through right atrial approach,
best illustrated through fishmouth incision in the ventricle
Operative Management
Surgical results
1 Septation
* Recently improved hospital mortality (10 - 30%)
* Late functional result : good
2 Fontan-type procedure
* Nearly same early and late result as other types of CHD
3 Palliative procedure
* Pulmonary artery banding
* Systemic-pulmonary shunt
* Atrial septectomy
Suitable Septation Operation
• Apparently, 20-25% of patients with double inlet
ventricle are suitable at birth for septation
• Somewhat, not severely, enlarged dominant ventricle
• Two reasonable competent and nonstenotic AV valves
with little or no overriding or straddling
• There should be little or no pulmonary or systemic
outflow obstruction
• Septation should be performed during the first year or
two of life
• Consideration should be given to a two-stage approach,
to minimize the probability of producing complete heart
block
Indications of Operation
Primary considerations in managing the
patients with double inlet ventricle of any
type are
(1) their suitability for septation, Fontan
operation, or cardiac transplantation and
(2) prevention of additional complicating
conditions such as subaortic stenosis or
pulmonary arterial stenosis
Atrial Isomerism
Atrial Isomerism
Definition
• Atrial isomerism is a condition in which the
right-sided and left-sided atria, normally
morphologically different, are morphologically
similar.
• Atrial isomerism is a subset of situs ambigus, a
condition in which usually asymmetric bodily
structures tend to be symmetric.
Morphology of Atrial Isomerism
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Bilateral right or left atria
Conduction system
Anomalies of systemic venous connection
Anomalies of pulmonary venous connection
Atrioventricular connection
Atrioventricular septal & other atrial septal defect
Ventricular morphology and VSD
Pulmonary outflow tract
Ventriculoarterial connection
Other coexisting cardiac anomalies
Clinical Features & Diagnosis
• There are no other clinical features specific to atrial
isomerism
• Asplenia is associated with an increased number of
Howell-Jolly bodies
• Clinical features depend, therefore, on other cardiac
anomalies that may present.
• Almost all with right atrial isomerism have sinus
rhythm, & complete heart block coexist in 10% of left
artrial isomerism, but rare in right atrial isomerism
• Echocardiography
• Cardiac catheterization
Natural History
• Determined primarily by details of cardiac structures
and nature of coexisting cardiac anomalies.
• However, atrial isomerism itself may contribute to
natural history because of its association with neonatal
complete heart block and sometimes neonatal death
• Right atrial isomerism is often accompanied by
asplenia, a condition believed to render the patient
susceptible to infection, particularly pneumococcal.
• Left atrial isomerism is often accompanied by a
polysplenia and a high prevalence of extrahepatic
biliary atresia
Operative Indications & Technique
 Need for surgical treatment is dictated by
associated cardiac anomalies, not by atrial
isomerism
 Technique
• Cardiopulmonary bypass
• Intracardiac repair
• Complex atrial baffle
• Fontan type repair
• Palliative operations
Complex Atrial Baffle
Results of Surgical Treatment
• Overall survival is better with left, compared to right
atrial isomerism
• Survival is better when a biventricular repair is
undertaken
• Although, overall outcomes of isomerism have been
poor, results have improved substantially over time
• In left atrial isomerism, one third possibly received by
biventricular repair, one third by Fontan, no palliation
in others.
• In right atrial isomerism, both short and long-term
outcomes are poor, and biventricular repair is possible
in few patients.
Incremental Risk Factors for Death
Left atrial isomerism
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Lower birth weight
Single ventricle
Gastrointestinal malformation
Biliary atrsia
Congenital AV block
Coarctation of aorta.
Right atrial isomerism
• Absence of pulmonary outflow obstruction
• Presence of AV valve anomaly
• Presence of obstructed pulmonary veins