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Patent Ductus Arteriosus
Seoul National University Hospital
Department of Thoracic & Cardiovascular Surgery
Patent Ductus Arteriosus
1. Definition
An open communication usually between upper
descending aorta and proximal portion of left pulmonary
artery and is the result of persistent patency of fetal
ductus arteriosus
2. History
* Galen
:
* Gibson
:
* John Strieder
:
* Robert E. Gross
:
* Rashkind & Cuaso :
1st description(Born in AD131)
Continuous murmur in 1900
Attempted to close in 1937
Successful ligation in 1938
Catheter closure in 1977
Pathophysiology of PDA
• Left-to-right shunt from the thoracic aorta to
the pulmonary artery leads to augmented
pulmonary blood flow, pulmonary
hypertension, and congestive heart failure.
• Demonstrating blood from across the ductus
with associated left ventricular hypertrophy
and left atrial enlargement and comprises
12~15% of congenital heart defects
Anatomy of Ductus Arteriosus
1. Position
* Unilateral
* Bilateral
* Absence ( 35-40% in TOF )
2. Histology of PDA
* Thick intima with unfragmented elastic lamina
* Media contains mucoid material with spiral muscular
intricate helicoid arrangement and elastic material
3. PDA as a coexisting anomaly
* Orientation of ductus to aortic arch varies
Morphology of Ductus Arteriosus
1. At birth
* Resembles a muscular artery
* Intima : intact wavy internal elastic lamina, split up
into several layers and interrupted
underneath intimal cushion
* Media : mainly circular smooth muscle cells with
minimal elastic fibers ( mucoid lake )
2. Anatomic closure
* Necrosis of cellular component of the media and
diffuse fibrous proliferation of intima
3. Aneurysms of ductus arteriosus
* Spontaneous infantile form
* Childhood or adult form
PDA Gross Finding
PDA
PDA
PDA
Postnatal Closure of Ductus Arteriosus
1. First Stage ( Functional closure )
* Within 10~15 hours after birth ( contraction of smooth muscle
& approximation of intimal cushion )
2. Second Stage (Anatomic closure )
* Completed by 2~3weeks ( fibrous proliferation of intima,
necrosis of media, hemorrhage in the wall and sealing of
the lumen )
* Ductus arteriosus is closed by 8 weeks in 88%
3. Physiology
* Vasoactive substances ( acetylcholine, bradykinin, endogenous
catecholamine and others ) by variations in PH, but chiefly by
02 tension and prostaglandins ( PGE1, PGE2, prostacyclin,
PGI2 )
Natural History of PDA
1. Incidence
* Isolated PDA : 1/2000 birth, 5-10% of CHD
* Sex ratio ; male : female = 1 : 2
2. Spontaneous closure
* 0.6% of patients per year. ( 20% by age of 60 )
* Uncommon over 3~5 months of age ( full term baby )
3. Death
* Untreated large PDA is high in infancy ( 30%)
* 42% of patients with PDA will die by age of 45
4. Mode of Death
* CHF in infancy
* CHF by 2nd or 3rd decade in large PDA ( PVR )
* CHF 3rd or 4th decade in moderate PDA
* Rare SBE
Clinical Features of PDA
1. Large PDA
* Severe congestive heart failure within a month
* Tachypnea, sweating, irritability, poor feeding,
2. Moderate PDA
* Large shunt from the 2nd or 3rd months of age
* Compensatory LVH with improvement & stabilization
3. Small PDA
* Symptoms are absent in infancy and childhood
* Continuous murmur
4. Silent PDA
* Controversial in surgical treatment
Operation of PDA
1. Indication
1) Large PDA is indicated beyond the 1st month of life, but
symptoms of heart failure is present, surgery is indicated
2) In the absence of symptom, operation delayed until
the age of about 6 months
2. Contraindication : severe pulmonary vascular disease
3. Technique of operation
1) Division :divided rather than ligation
2) Ligation : In neonate or some infant
3) Closure of PDA in older adults
* Using CPB (calcified aortic end, short ductus, PH)
4. Percutaneous closure ( Rashkind, Amplatzer, Coil )
5. Thoracoscopic closure
Anatomy of PDA
• PDA as visualized from a left anterior oblique view
PDA Exposure
Operative Exposure of PDA
• PDA through a left thoracotomy & the mediastinal pleura
is opened and reflected anteriorly and posteriorly
Median Approach of PDA
• Closure of PDA from a median sternotomy approach
PDA Ligation
PDA Division
Thoracoscopic Surgery (VATS)
• Indications
Isolated PDA associated with or without other
minor cardiac lesions
• Contraindications
Complex congenital defects requiring CPB
Ductus diameter larger than 9 mm
Calcification of ductus
Pleural adhesion or right aortic arch
Thoracoscopic Surgery (VATS)
• Why VATS PDA ligation
-- Potential thoracotomy morbidity
Long-term post-thoracotomy pain
Postoperative pulmonary complication
Thoracic scoliosis
-- VATS PDA ligation
Decrease chest wall trauma
Minimize nerve injury & rupture of intercostal ligament
Cosmetic effect
Painless
PDA Ligation by VATs
• An endoscopic vascular clip is placed to interrupt
the patent ductus arteriosus. The arrow denotes
the recurrent laryngeal nerve
Operative Results of PDA
1) Mortality
2) Incremental risk factors for early death
* old age
* pulmonary vascular disease
3) Survival
4) Symptomatic and functional status
5) Physical development
6) Recurrence
7) False aneurysm
8) Vocal cord paralysis
9) Phrenic nerve paralysis
10) Chylothorax
Management of Pre-term PDA
• General management
Fluid restriction
Ventilatory support
Correction of anemia
Correction of metabolic acidosis
Diuretics; lasix decrease ECF volume,
but increase prostaglandin production
• Indomethacin
• Other cyclooxygenase inhibitor
Ibuprofen
Mefenamic acid
• Surgical treatment
PDA in Pre-term Baby (1)
1. Incidence
Increase with decreasing gestational age & birth weight,
but hemodynamic significancy is less.
28 ~ 30wks : 77%
Wt under 1000gr : 40%
31 ~ 33wks : 44%
Wt under 1750gr : 10%
34 ~ 36wks : 21%
2. Operative indications
Failure of indomethacin trial
Respiratory distress
Necrotizing enterocolitis
Intracranial hemorrhage
PDA in Pre-term Baby (2)
3. Operative results
Early mortality : 10~30%
Respiratory distress
Intracranial hemorrhage
Diffuse coagulopathy
Late
: BPD in 1/3 of survivor
Complications (CP, retrolental fibroplasia)
in 1/6 of survivor