Ventricular Septal Defect

Seoul National University Hospital

Department of Thoracic & Cardiovascular Surgery

Primary Ventricular Septal Defect

1. Definition A hole or multiple holes in the interventricular septum. A VSD may be part of another major cardiovascular anomaly and may be acquired, and primary VSD may have minor coexisting morphologic abnormalities 2. History Roger : 1st description in 1879 Eisenmenger : Autopsy finding in 1897 Lillehei, Varco : Repair using controlled cross circulation in 1954 DuShane et al in Mayo Clinic : Intracardiac repair with pump oxygenator in 1955~1956 Lillehei : Atrial approach to VSD in 1957

Ventricular Septal Defect

1. Embryology VSD occurs at 1st. 8 weeks of fetal life through interaction

between interventricular muscular partition, endocardial

cushions, and bulbar ridges that separate great vessels.

2. Etiology Chromosomal Familial Geographic Environmental

Ventricular Septal Defect

Pathophysiology• Defect in the interventricular septum permits

left-to-right shunting of blood• RV volume overload & pulmonary overcirculation

can produce congestive heart failure in infancy & irreversible pulmonary hypertension later in life

• Shunt reversal (right-to-left) due to elevated pulmonary vascular resistances leads to systemic hypoxemia (Eisenmenger syndrome)

Morphology of VSD

1. Size 1) Large : approximately the size of aortic orifice 2) Moderate : still restrictive, but sufficient size to raise RV pressure to ½ of LV and Qp/Os>2.0 3) Small : insufficient size to raise RV pressure & Qp/Qs < 1.75

2. Location 1) Perimembranous VSD : 80% 2) VSD in RV outlet : 5-10% 3) Inlet septal VSD : 5% 4) Muscular VSD : 5% 5) Confluent VSD 6) VSD with straddling or overriding TV

Morphologic Classification of VSD Classification Extension Perimembranous Inlet (junctional) Anterior Outlet Muscular Outlet (conal) Trabecular Inlet Anterior Apical Doubly committed subarterial (RV outlet) Inlet septal Atrioventricular septal type Malalignment Anterior (TOF) Posterior (COA, IAA) Rotational (Taussig-Bing)

Morphologic Types of VSD

VSD MO type

VSD MO type

VSD PMOE type

VSD PMIE type

VSD PMIE Type

Associated Lesions with VSD

1. PDA

6% of all ages, 25% of infants in heart failure

2. COA ; 5%

3. Congenital aortic stenosis

2% requiring operation for VSD (sub AS> valv AS)

4. Infundibular pulmonary stenosis

5. Congenital mitral valve disease ; 2%

6. Absent pulmonary arteries, peripheral PS

7. Positional anomalies

Pulmonary Vascular Disease

Grade I : Medial hypertrophy without intimal proliferation.

II : Medial hypertrophy with cellular intimal reaction.

III : Intimal fibrosis, as well as medial hypertrophy,

early vascular dilation.

IV : Generalized vascular dilation, areas of vascular

occlusion by intimal fibrosis & plexiform lesion.

V : Other dilation lesion such as cavernous and

angiomatoid lesions.

VI : Necrotizig arteritis in addition to grade V changes

Clinical Features & Diagnosis 1. Prevalence 2 per 1,000 live births 20% of CHD Associated & isolated VSD : 50% of CHD Higher incidence in premature

2. Clinical features Symptoms and signs of heart failure Cardiomegaly & large pulmonary blood flow Pansystolic or systolic murmur Biventricular or left ventricular hypertrophy

3. Two-dimensional echocardiography

4. Cardiac catheterization & angiocardiography

Natural History of VSD

1. Spontaneous closure

2. Pulmonary vascular disease

3. Bacterial endocarditis ; rarely recently

4. Premature death

5. Clinical course

6. Development of aortic incompetence

7. Development of infundibular PS

Spontaneous Closure of VSD

1. Mechanism of narrowing or closure 1) Adherence of TV leaflet or chordae tissue

2) Aneurysm of membranous septum erroneously related

-- rare in conoventricular, juxtaarterial, AV canal,

muscular defect

2. Rate About 80% of VSD at 1 month eventually narrow or close About 60% of VSD at 3 months eventually narrow or close About 50% of VSD at 6 months eventually narrow or close About 25% of VSD at 12 months eventually narrow or close Becomes rare after 12 ~ 18 months of age

VSD Spontaneous Closure

Probability

Pulmonary Vascular Resistance

Resistance Description < unit/BSA <

< 4 Normal

4 ~ 5 Mild elevated

5 ~ 8 Moderately elevated

8 > Severely elevated

PA Banding in VSD of PVD ?

• This increases right-left shunt, the saturation in the aorta will fall, and so does the venous blood returning to the RA (maximally desaturated).

• For the lungs, shock means low oxygen and pressure in the PA and shock is the most potent vasodilator in the body, mainly in the PA.

• To reverse completely lung lesions "extracting oxygen from the PA . Once you extract it, the lung lesions reverse completely

• What causes hyperresistant PA hypertension is the quantity of oxygen in the PA. If the PA would have had hyperflow with low oxygen, it would not have developed hyperresistant pulmonary hypertension

Indications for Operation

1. Severe and intractable heart failure or respiratory

symptoms during the 1st 3months of life.

2. Severe symptoms, growth failure, rising PVR

older than 3 months of age.

3. VSD with PVR more than 4 unit during 6-12 months.

4. VSD with elevated PVR first seen after infancy.

5. Moderate VSD with no size change in childhood.

6. Juxtaarterial , juxtaaortic VSD is a special situation.

Techniques of Operation

1. Route 1) Right atrium 2) Right ventricle, or left ventricle 3) Pulmonary artery

2. Repair of VSD 1) Conoventricular VSD 2) Juxtaarterial VSD 3) Inlet VSD 4) Muscular VSD

3. Closure of associated PDA

4. Pulmonary artery banding & debanding

VSD. Surgical Anatomy

VSD Operation

VSD – AV Canal type

VSD - PM Operative View

VSD – PM Patch Closure (1)

VSD – PM Patch Closure (2)

VSD. PMIE Patch Closure (1)

VSD. PMIE Patch Closure (2)

VSD. PMOE Patch Closure

• VSD closure through anterior leaflet of TV detachment

RV Anatomy for Apical VSD

Apical Muscular VSD Patch Closure via RVtomy

Apical Muscular VSD Patch Closure via RVtomy

(A) Trabeculations overlying the VSD are taken down. (B) Interrupted pledgetted sutures are placed full thickness at the superior margin of the defect, maintaining the pledgets on the left ventricular side (C) Closure of the VSD with a Dacron patch

Flap Valve Double Patch Closure

• Flap valve double patch closure of Ventricular Septal Defects in children with Increased Pulmonary Vascular Resistance

Closure of Trabecular VSD Sandwich Technique

• Sutures & patch can be passed through the other VSD or mitral valve

Results of Operation for VSD

1. Hospital mortality

2. Modes of early death

3. Incremental risk factors

for hospital death 1) Early date of op. 2) Multiple VSD

3) Associated anomalies 4. Survival Pulmonary vascular D.

5. Physical development

6. Conduction disturbance

7. Cardiac function

8. Residual shunting

9. Pulmonary hyperinflation

10. Iatrogenic aortic or

tricuspid incompetence

11. Pulmonary hypertension

Special Situation & Controversies

1. VSD and patent ductus arteriosus

2. VSD and coarctation of aorta

3. Pulmonary artery banding

4. Approach for conoventricular VSD

5. Percutaneous closure of VSD

6. Closure of VSD when PVR is high