4. Pulmonary sequestration
ā¢ Pulmonary sequestration is defined as a
dysplastic pulmonary tissue that does not
communicate with the tracheobronchial
tree
ļ It receives its blood supply from the
systemic circulation usually from aorta.
5. Pulmonary sequestration
The anomalous blood supply can result in
ā¢ high-output cardiac failure because of
substantial arteriovenous shunting
through the BPS
ā¢ or bleeding with massive hemoptysis or
hemothorax.
6. Pulmonary sequestration
ā¢ The term āsequestration,ā was first
used in the medical literature by
Pryce in 1946.
ā¢ Represents 0.15- 6% of all
pulmonary malformations.
7. Pulmonary sequestration
ā¢ Originates from accessory lung bud inferior
to the normal lung bud.
ā¢ Another explanation is that a portion of the
developing lung bud is mechanically
separated from the rest of the lung by
ā compression from cardiovascular
structures
ā traction by aberrant systemic vessels, or
ā inadequate pulmonary blood flow
8. Pulmonary sequestration
There are 2 distinctive forms of pulmonary sequestration:
intralobar sequestration 75%
Extralobar sequestration
9. Pulmonary sequestration
ā¢ An extralobar sequestration may reside in
the chest, within the diaphragm, or in a
sub-diaphragmatic location.
ā¢ Intralobar and extralobar sequestrations can
occur simultaneously.
ā¢ An entire lung can be sequestered.
ā¢ Bilateral sequestrations have been reported
but are very rare.
10. Intralobar pulmonary sequestration
ā¢ The intralobar variety accounts for 75
percent of all sequestrations
ā¢ Intralobar sequestration is contained
within the normal visceral pleura.
ā¢ It is usually located in the posterior basal
segments of the lower left lobe.
11. Intralobar sequestration ILS
ā¢ The arterial supply is from the descending thoracic aorta
through inferior pulmonary ligament in 90% of cases
ā¢ Other arterial sources could be the
Ā» intercostal artery,
Ā» subclavian arteries,
Ā» internal thoracic arteries and
Ā» sometimes coronary arterial
ā¢ Venous drainage is via the pulmonary veins into left
atrium.
12. Intralobar sequestration ILS
ā¢ Intralobar sequestration is rarely
symptomatic
ā¢ When present symptoms are nonspecific
Ā» chest pain
Ā» pleuritic pain
Ā» shortness of breath
Ā» Wheezing and
Ā» recurrent infection
13. Intralobar sequestration ILS
ā¢ Presents in childhood to adult as
recurrent pneumonias.
ā¢ Males and females are equally affected
with ILS
ā¢ The recurrent localization of the
pathology in the lower lobe suggests the
diagnosis
14. Extralobar pulmonary Sequestration
ā¢ It is a mass of abnormal lung tissue invested in
its own pleural covering.
ā¢ Three times less frequent than the intralobar
type (25%).
ā¢ usually is associated with other congenital
anomalies
Ā» congenital diaphragmatic hernia
Ā» Pectus excavatum
Ā» vertebral anomalies.
15. Extralobar pulmonary Sequestration ELS
ā¢ It is located usually in the left costophrenic
groove.
ā¢ About one-sixth are located below the
diaphragm.
ā¢ The arterial supply is in most of the cases
arises directly from the thoracic or
abdominal aorta.
16. ELS
ā¢ Venous drainage is almost always in the
ļAzygos
ļHemiazygos veins.
ļ Rarely venous drainage is in the
pulmonary veins
17. ELS
ā¢ Extralobar sequestration has a male
predominance (80%).
ā¢ ELS is usually asymptomatic and
discovered incidentally on a routine X-
ray.
ā¢ ELS may cause severe respiratory distress
in newborn OR feeding difficulties
18. ELS
Ā»Older infants and children may present
with
ā¢ congestive heart failure
ā¢ mitral regurgitation.
Ā»In some particularly uncommon cases the
sequestration can produce even frank
hemoptysis
19. Feature Intralobar sequestration Extralobar sequestration
Age at diagnosis Child to adult Neonate
Sex distribution Equal 80% male
Location Posterior basal left
segment
Independent of lung
Associated anomalies Uncommon Common
Venous drainage Pulmonary Systemic
Bronchial
communications
Present none
20. Diagnosis
Prenatal ultrasound:
ā Homogeneous, echogenic, well defined
mass in a paraspinal location, most often
the left lower thorax.
āFeeding artery originating from the
descending aorta can be seen on color
Doppler US
21. Prenatal ultrasound of a sequestration
A) Well defined hyperechoic lesion in the fetal thorax
B) Color Doppler image which shows the arterial supply of the lesion
22. Chest X-ray
āit is difficult to distinguish between ELPS
and ILPS on plain radiographs alone
ā ELPS is usually found as
ā¢ well defined
ā¢ retro cardiac masses
ā¢ in the cardiophrenic angle
ā Air bronchogram is absent
23. Chest X-ray
ELPS
āIt may be found as a sub-diaphragmatic or
mediastinal mass lesion.
ā It can be associated with opaque
ipsilateral hemithorax and pleural effusion
26. Chest X-ray
ā¢ ILPS is
ā more heterogeneous and
ā less well defined.
ā¢ Focal bronchiectasis, areas of
atelectasis, cavitaion, and cyst
formation may also be recognized.
29. CT
ā¢ CT scans have 90% accuracy in the diagnosis of
pulmonary sequestration.
ā¢ The most common appearance is homo- or
heterogeneous mass with cystic changes.
ā¢ Less frequent findings include a large cavitary
lesion with an air-fluid level
ā¢ Emphysematous changes at the margin of the
lesion are characteristic
30. CT
ā¢ CT-angiography techniques and 3-
dimensional images can help to show
aberrant arterial supply and anomalous
drainage.
ā¢ Helps in the surgical planning
38. Treatment
ā¢ The management of a pulmonary
sequestration diagnosed during
fetal life involve
ā the conservative treatment and
ultrasound or MRI follow-up.
ā¢ Partial or complete regression
during pregnancy is possible.
39. Treatment
ā¢ Fetal intervention and excision of
the lesion during fetal life is
required only if
ā¢ signs of fetal distress,
ā¢ cardiac or vena caval compression
appears
40. Treatment
ā¢ After birth therapy will have to be
individualized depending on
ā¢ symptoms,
ā¢ the nature of the sequestration, and
ā¢ the presence of any associated
malformation.
41. Treatment
ā¢ Small Intralobar asymptomatic
lesions benefit in many cases of
conservative treatment with careful
long-term surveillance .
42. Treatment
ā¢ Other experts advocate that even asymptomatic
lesions should be surgically removed .
ā¢ Reasons for surgical excision of an asymptomatic
lesions
ā risk of recurrent infections,
ā an increase in the arterio-venous shunt,
ā pressure effect on adjacent normal lung, airway
compression
43. Treatment
ā¢ Surgical treatment is required in symptomatic
lesions.
ā¢ Surgery usually involves lobectomy via thoracotomy
or Thoracoscopy.
ā¢ Special care must be taken when the vessels are
handled, because of their increased fragility.
ā¢ Care must be taken also during dissection not to
produce injury to the phrenic nerve.
46. Congenital lobar hyperinflation
ā¢ formerly called congenital lobar
emphysema, is characterized by
progressive over-inflation of a lobe
ā¢ results from a check-valve mechanism at
the bronchial level that causes
progressive hyperinflation of the lung.
47. Congenital lobar hyperinflation
ā¢ The collapsed airway can act as a one-way
valve, resulting in the air trapping.
ā¢ Affected lobe is unable to deflate normally
48. Congenital lobar hyperinflation
ā¢ It can either be congenital or acquired.
ā¢ The underlying cause can be secondary to
ā intrinsic cartilaginous abnormality or
ā extrinsic compression of an airway.
49. Congenital lobar hyperinflation
ā¢ Intrinsic narrowing can be produced
by the weakness or absence of
bronchial cartilage.
ā¢ There is air entry but collapse of the
narrow bronchial lumen during
expiration prevents deflation.
50. Congenital lobar hyperinflation
ā¢ Extrinsic compression may be by
ā¢ A large pulmonary artery,
ā¢ a prehilar bronchogenic cyst,
ā¢ an enlarged mediastinal node,
ā¢ an aneurysmal ductus arteriosus
ā¢ The affected cartilage rings become malformed,
soft, and collapsible
51. Congenital lobar hyperinflation
ā¢ muscular coat defect
ā¢ mucous membrane fold &
ā¢ Stenosis
ā¢ have also been implicated in the
development of CLE
52. Congenital lobar hyperinflation
Air trapping in the emphysematous lobe may be the
result of
ā¢ dysplastic bronchial cartilages creating a ball-valve effect
ā¢ endobronchial obstruction from inspissated mucus or
extensive mucosal proliferation
ā¢ extrinsic compression
ā¢ diffuse bronchial abnormalities
ā¢ Careful preoperative bronchoscopy may help
delineate an intrinsic obstructive lesion
53. Congenital lobar hyperinflation
ā¢ Polyalveolosis, or the polyalveolar lobe first
described by Hislop and Reid, has been
found in some cases of congenital lobar
emphysema.
ā¢ The total alveolar number is increased
several-fold in this condition,
54. Congenital lobar hyperinflation
ā¢ The polyalveolar lobe becomes hyperinflated and
hyperlucent on radiography
ā¢ Clinical presentation and imaging cannot
differentiate between true CLE and polyalveolar
lobe,
ā¢ Hence, the term ācongenital lobar overinflationā
has been used to include both entities
55. Congenital lobar hyperinflation
ā¢ The most commonly affected lobe is
the left upper lobe.
ā¢ followed by the middle lobe and
the right upper lobe.
56. Congenital lobar hyperinflation
ā¢ The distribution of lobar involvement is
ā 42.2% in the left upper lobe,
ā 35.3% in the right middle lobe,
ā 20.7% in the right upper lobe, and
ā 0.9% in each lower lobe
57. Congenital lobar hyperinflation
ā¢ occurs in 1/20,000 to 1/30,000.
ā¢ The upper lobes tend to be the most
frequently involved.
ā¢ with the left side more common (40
to 50%) than the right (20%).
58. Congenital lobar hyperinflation
ā¢ More common in boys (Male to female ratio is about 3
to 1)
ā¢ Most patients become symptomatic during
the neonatal period with respiratory
distress.
ā¢ The remaining 50% develop symptoms in
the first 4 months.
59. Congenital lobar hyperinflation
ā¢ Myers described three clinical types
ā¢ symptomatic in infancy (type I),
ā¢ in older children (type II), or is an
incidental finding in
ā¢ asymptomatic patients (type III).
ā¢ Types II and III are rare
60. Congenital lobar hyperinflation
ā¢ In about 10% of patients associated
congenital anomalies are present,
primarily congenital heart disease.
61. Congenital lobar hyperinflation
ā¢ The typical postnatal presentation is that of
a new-born showing signs of progressive
respiratory distress
ā¢ Respiratory distress in varying severity is
present in 50% of the cases at birth.
63. Congenital lobar hyperinflation
ā¢ Physical examination shows:
ļ asymmetry of chest
ļ abdominal retractions on inspiration
ļ hyper resonance and diminished or absent
breath sounds in the affected area
64. Congenital lobar hyperinflation
ā¢ The diagnosis is made on X-ray of
the chest showing a:
ļ hyperlucent over expanded area.
ļ compression of the remaining lung
on that side
65. X-ray chest
ā¢ It can also show
ā widening of the ribs spaces,
ā depression of the diaphragm,
ā mediastinal shift.
ā Compression of the contralateral
lung.
66. X-ray chest
ā¢ Chest radiograph:
expanded left lung with
mass effect
ā¢ (mediastinal shift to the
right
ā¢ and increased left
intercostal space)
67. X-ray chest
ā¢ The patient may also present with a
radio-opaque mass on X- ray chest.
ā¢ because of delayed clearance of lung
fluid of the affected lobe
68. X-ray chest
ā¢ As the fluid is absorbed, the affected segment
or lobe becomes hyperlucent
ā¢ Adjacent lobes and structures may be
compressed by the emphysematous lobe
ā¢ sometimes ipsilateral and contralateral
atelectasis may occur
69. X-ray chest
ā¢ The ipsilateral atelectatic lung is seen as a
small, triangular density in the apical or
supradiaphragmatic region
ā¢ the adjacent lobe collapses either caudad or
cephalad but not medial, towards the hilum
ā¢ lateral film may demonstrate posterior
displacement of the heart
70. X-ray chest
ā¢ Congenital lobar emphysema may
be confused with pneumothorax
or with a simple lung cyst or
acquired cyst.
ā¢ In congenital lobar emphysema,
there are bronchovascular
markings within the overdistended
lobe
71. CT
ā¢ Computed tomography scanning can
provide:
ā¢ More accurate information of the
overdistended lobe.
ā¢ its vascularity
ā¢ as well as information about the
remaining lung
72. CT
ā¢ A) Axial CT
image marked
hyperlucency
of the left
upper lobe,
compatible
with congenital
lobar
hyperinflation
74. Treatment
ā¢ Surgicalresection is not needed when
ā¢ infants have very mild symptoms that do
not progress,
ā¢ emphysematous lobe remains stable and
does not encroach on adjacent lung
75. Treatment
ā¢ Surgical intervention and resection of the
affected lobe is required when patient is
Symptomatic
ā¢ The surgical procedure in most of the cases
is lobectomy and sometimes
segmentectomy by open or thoracoscopic
approach
76. Treatment
ā¢ complete lobectomy instead of a wedge or
segmentectomy of the involved lobe is
preffered.
ā¢ Lobectomy favored because of the difficulty,
on a macroscopic level, of determining what
portion of the lung is involved and which is
not.
77. Treatment
ā¢ The increased difficulty and morbidity
associated with a partial resection does
not warrant the
ā¢ limited benefits of preserving a portion
of possibly diseased lung
78. Treatment
ā¢ segmentectomies is done
ā In cases where more then one lobe appears to
be involved or there maybe bilateral disease.
ā Or in cases where there are no clear anatomic
planes between the upper and lower lobe
lobes and segments of both are grossly
involved.
79. Treatment
ā¢ The symptomatic neonate needs to
be operated on immediately.
ā¢ In extreme cases an emergency
thoracotomy with decompression of
the chest cavity can be a life saving
intervention and an emergency
lobectomy is performed.
80. Treatment
ā¢ The timing of surgery remains somewhat
controversial but there is little evidence to
suggest that delayed resection benefits the
child in any significant way.
ā¢ In fact delayed surgery may increase the risk
of infection or respiratory compromise.
ā¢ Also early resection maximizes the
compensatory lung growth of the remaining
lobe
81. Treatment
ā¢ Many centers have recommended resection at
between 1 to 6 months of age to
ā¢ allow for some growth and to decrease the
risk of the anesthesia.