THE PLEURA
GENERAL THORACIC SURGERY
SECTION XI
ANATOMY OF THE PLEURA
• EMBRYOLOGY
• Pleural cavity derivatives of primitive coelom—
from splitting of the lateral mesoderm into
splanchnic and somatic layers.
• The paired cavities separated by three partition into
three subdivision: 1). Pericardial, 2). Pleural, 3).
Peritoneal cavity.
• The three partition are: 1). Unpaired septum
transversum, 2) Paired pleuropericardial folds, 3)
Paired pleuroperitoneal folds.
• 4 weeks of development, laryngotracheal outgrowth
from the floor of pharynx.
• 5 week of development, two lung buds begin
enlarge.
ANATOMY OF THE PLEURA
• HISTOLOGY
• The two layers of pleura have the similar
histologic features.
• The parietal pleura have stomata.
• Each layer consists: 1) Innermost mesothelial cell
layer, 2) Submesothelial interstitial connective
tissue layer, 3) Inner thin elastic fiber layer, 4)
Outer interstitial connective tissue layer, 5) Thick
elastic fiber layer. 6) Another fatty layer separate
the parietal pleura and the muscle of chest wall.
ANATOMY OF THE PLEURA
• HISTOLOGY
• The mesothelial cell vary in thickness, diameter,
shape. The mesothelial cell demonstrate microvilli,
tight apical junctions, the gap junction,
desmosomes, half desmosomes. ( infrequently on
the basal part of the cell menbrane)
• In immunohistochemically, the mesothelial cell
express low and high-molecular weight cytokeratin
• Normal mesothelial cell are negative for reaction
to vimentin, epithelial menbrane antigen,
carcinoembryonic antigen, factor VIII-related
antigen.
ANATOMY OF THE PLEURA
• HISTOLOGY
• Submesothelial layer contains collagen
tissue, elastic fiber, small blood vesels,
lymphatic network, nerve fiber. The cell in
this layer is fibroblast, negative of
cytokeratin, carcinoembryonic antigen,
factor VIII-related antigen.
ANATOMY OF THE PLEURA
• HISTOLOGY
• Visceral and parietal pleura are the same thickness,
30-40μm.
• The parietal pleura has large deiscences or stomata, 26μm, connect the pleural cavity with subpleural
lymphstic network and permit egress of material into
the lymphatics from the pleural space.
• Focal accumulations of macrophages alone the
pleuripotential mesenchymal lymphoid plasma cell in
caudal portion of mediastinal pleura may functionally
related to stomata.
ANATOMY OF THE PLEURA
• GROSS ANATOMY
• Visceral pleura is closely applied to the lung
surface, the cleavage plane is absence.
• It line the major and minor fissure. The minor
fissure may incomplete to absence in 50%.
• The pulmonary ligment extend from hilar to
diaphragm is consists of two apposed layer of
visceral pleura and became continue with the
parietal pleura.
ANATOMY OF THE PLEURA
• GROSS ANATOMY
• The parietal pleura lines the chest wall,
mediastinum, diaphragm, and form the cupola or
pleura dome at the thoracic inlet bilaterally.
• The diaphragmatic pleura adheres tightly to the
diaphragm. The mediastinum pleura adherent
tightly to pericardium. The cupola, costal pleura
can dissected from the underlying tissue.
• The pleura recesses, usually two visible at chest
PA, termed the 1) Azygoesophageal recess and the
2) Superior esophageal recess
ANATOMY OF THE PLEURA
• BLOOD SUPPLY
• Visceral pleura--- Artery supplied by
bronchial and pulmonary arterial systems.
The veins drain is pulmonary vein.
• The parietal pleura--- Artery supply is from
various systemic arterial supply the chest
wall, diaphragm, and mediastinum.Vein is
to the superior vena cava.
ANATOMY OF THE PLEURA
• LYMPHATIC DRAINAGE
• Subpleural space of the visceral pleura has large
network of lymphatic channel but rarely
subpleural lymph node.
• The intrapulmonary lymph node incidence is 18%,
nearly no node in subpleural space.
• The lymphatic drainage of the visceral is to the
pulmonary plexus located in interlobar and
peribronchial space. The direct subplerual
lymphatic connection to mediastinal node is 2225%.
• Subpleural connections were more in upper lobe
than in lower lobes.
ANATOMY OF THE PLEURA
• LYMPHATIC DRAINAGE
• Lymphatic drainage of the parietal pleural is into
the parietal pleural lymphatic channels, the
stomata and Kampmeier’s foci play an important
role.
• The lymphatic network of the chest wall drain into
internal mammary chain anteriorly and
intercostals chain posteriorly.
• The drainage of the diaphragmatic pleura is to
retrosternal and mediastinal and celiac lymph node.
ANATOMY OF THE PLEURA
• NERVE SUPPLY
• Parietal pleura is innervated by both
somatic
and
sympathetic
and
parasympathetic fiber via the intercostal
nerve.
• The diaphragmatic pleura is supplied by
phrenic nerve.
• The visceral pleura is devoid of somatic
nerve.
RESORPTION OF GASES FROM
THE PLEURAL SPACE
1. Normal condition: no free gases in the pleural
space.
2. The virtual space between the parietal and
visceral pleura is under negative pressure relation
to atmosphere.
3. Normal condition: respiratory muscle in relaxtion
state, the pressure is 5cm-H2O lower than
surrounding atmosphere. The pressure decrease
further during inspiration.( Especially the airwar
obstruction, during Müller maneuver the pleural
pressure can become negative to lower than 100
cm -H2O).
RESORPTION OF GASES FROM
THE PLEURAL SPACE
• FACTORS DETERMINING GAS RESORPTION
• By a simple diffusion from the pleural space into
the venous blood.this diffusion occurred in both
directions.
• No active transport mechanism for gas resoprtion.
• The only driving forces that determine gas
resorption are pressure gradients.
RESORPTION OF GASES FROM
THE PLEURAL SPACE
• The rate of gas resorption depends on four variables:
• 1. Diffusion properties of gas.
• 2. The pressure gradient for the gas in pleura in
relation to venous blood.
• 3. The area contact between pleura gas and pleura.
• 4. Permeability of the pleural surface.
• Ex: the oxygen is resorbed 62 times faster than
nitrogen, CO2 23 times more soluable than O2. water
and CO2 are equilibrate.
RESORPTION OF GASES FROM
THE PLEURAL SPACE
• PHASE OF GAS RESORPTION
• Two phase in gas resorption.
• Phase 1: equilibration of gases partial
pressure.
• Pahse 2: constant resorption.
RESORPTION OF GASES FROM
THE PLEURAL SPACE
• Three potential situation of pneumothorax
result in different behavior of gas resorpion
1. Close rigid cavity:
Non-reexpandable lung, could remain air
filled. If the negative pressure is maintained
fluid eventually seep into pleural cavity and
gradually fills it, which subsequently
solidifies and fibroses.
RESORPTION OF GASES FROM
THE PLEURAL SPACE
• 2. Closed collapsible cavity:
The most frequent form of pneumothorax. It
occurs when gas enter the pleural space, the
opening responsible for pneumothorax becomes
occluded, and lung are freely reexpabdable. As the
gases resorbed no new gas enter the pleural space
and the reexpansion of lungs compensates the
volume, prevent the appearance of negative
intrapleural pressure. It has been estimated that
6% of pneumothorax is absorbed in 24 hours.
RESORPTION OF GASES FROM
THE PLEURAL SPACE
• 3. Open cavity: the communication between
the pleural cavity and the lung or through
the thoracic wall persist the lung dosen’t
reexpand.
RESORPTION OF GASES FROM
THE PLEURAL SPACE
• Different altitude in different barometric
pressure.
• Pneumothorax of 1-L volume would increase
33%if the patient was transported in an
airplane pressurized at 8000 feet.
• If a pneumothorax develop in deep sea 30 feet
below the surface, the volume of
pneumothorax would double as the diver
resurfaces.
RESORPTION OF GASES FROM
THE PLEURAL SPACE
• THERAPEUTIC CONSIDERATION
• 100% O2 is given to patient during a maneuver at high risk
of creating pneumothorax (ex. transthoracic lung biopsy).
• Reasons:
• 1. The pneumothorax is filled with more soluble O2.
• 2. the pressure greadient between pneumothorax and
venous blood is larger because the 100% O2 washes out N2
from alveoli and eventually the venous blood.
• The beneficial effect in relative small and not clinically
useful.
PNEUMOTHORAX
•
•
•
•
ETIOLOGY
PRESENTATION
DIAGNOSIS
TREATMENT
PNEUMOTHORAX
• The most common cause of primary
spontaneous pneumothorax is rupture of an
apical subpleural bleb.
• The etiology is obscure--- Difference in
alveolar pressure in upright human between
the base and the apex.
PNEUMOTHORAX
• Spontaneous pneumothorax is rarely seen
befor puberty. Children with spontaneous
pneumothorax often have underlying
disease such as cystic fibrosis.
• More common in men (6:1).
• More common in smoker.
• Typical patient is young, tall, thin man in
late adolescence and early adulthood.
PNEUMOTHORAX
• PRESENTATION
• Sudden onset chest pain, shortness of breath,
not in engaging in any unusual or strenuous
activity.
• Spontaneous pneumomeiastinum
is
invariably associated with strenuous
exertion such as bench-press weight lifting.
PNEUMOTHORAX
• Special mention of secondary spontaneous
pneumothorax associated with AIDS with
Pneumocystitis pneumonia .
• The most common sarcomna contributing to
pneumothorax are osteosarcoma and
synovial sarcoma.
PNEUMOTHORAX
• Spontaneous rupture of esophagus present as
pneumothorax without gastrointestinal symptoms.
• Pneumothora accompanying pleural fluid,
atelectasis. spontaneous pneumothorax with
COPD especially with bullae formation is
troublesome, tolerate poorly even small degree of
collapse.
• Catamenial pneumothorax, occurred first three
days of menses, nonovulatory states such as
pregnancy and oral contraceptive use were not
associated with pneumothorax.
PNEUMOTHORAX
• Lung cancer with pneumothorax only 0.03 to
0.05%.
• Lymphangioleiomyomatosis seen in young women.
• Acquired pneumothorax is most often iatrogenic,
chest tube dysfunction.
• Barotraumas pneumothorax is patient receving
positive-pressure
ventilation---treated
by
intervention rather than observation, indication for
tube thoracostomy.
PNEUMOTHORAX
• Tension pneumothorax:
• Symptoms and sign: tachycardia, sweating,
hypotention, mediastinal shift.
• Clinical diagnosis of tension pneumothorax
made on basis of appropriate history and
physical findings is adequate to allow for
emergency placement o chest tube without
confirmatory chest radiography.
PNEUMOTHORAX
• DIAGNOSIS: standard procedure is making chest
x ray posteroanterior projection.
• Should upright position, may miss a
pneumothorax in semisupine portable
anteroposterior view.
• Lateral decubitus view if patient can’t be upright.
• The percentage of collapse is underestimated.
Artifact skin fold.
• CT, cost effective.
PNEUMOTHORAX
• Small
fluid
collections
frequently
encountered if pneumothorax over 24 hours.
• The fluid always clear.
• Large effusion often bloody and suggest a
torn vascular adhesion, may require
immediate operation to control bleeding.
PNEUMOTHORAX
• Important to exclude a giant bullae in
differential diagnosis because the tube
drainage if such bullae is unrewarding.
• Patient with pneumothorax should not be
encouraged to travel by air.
PNEUMOTHORAX
• 1.5% of the air is reabsorbed over each 24 hours.
• Tube thoracostomy for pneumothorax over 30% or
for patient with heart disease or COPD.
• Tube place at anterior and mid-axillary line, less
muscle tissue has to be traversed.
• Anterior tube through second intercostal space,
provide excellent apical air clearance but avoided
in women.
PNEUMOTHORAX
• The tube is placed by clump or trocar.
• The trocar technique for its speed and
convenience.
• Pleur-evac drainage set to water-seal and
gentle suction 20 cmh2op.
• Routine suction may cause reexpansion
pulmonary edema.
• Chance of recurrence: 20-50%.
PNEUMOTHORAX
• Various agents for induce pleural symphysis:
siver nitrate, talc, hypertonic glucose, urea,
oil, nitrogen mustard, various antibiotics.
• Intrapleural tetracycline instillation could
reduce the incidence of recurrence but
difficulty to obtain.
• Talc should be reserved for malignant
effusion, not benign pneumothorax.
PNEUMOTHORAX
• Open operation by limited lateral or axillary
incision with bleb excision and pleural
abrasion or limited apical pleurectomy--excellent result, low recurrence.
• Video-assisted thoracic surgery（VATS）.
• The recurrence rate is more high in VATS
than other minithoracotomy.
PNEUMOTHORAX
• Complete parietal pleurectomy should be
reserved for open treatment failure, for
postpneumonectomy patient with first
pneumothorax and for old patient usually
with COPD.
• Bilateral pneumothorax could be treated for
bilateral via median sternotomy.
PNEUMOTHORAX
• Goal of surgical treatment is to find the
offending bleb, remove it, encourage
adhesion formation but not too dense an
adhesion.
• If no bleb is found, the apex of the upper
lobe should be staple off.
PNEUMOTHORAX
• Surgical treatment of AIDS patient: usually
persistent air leak.
• Thoracoscope approach with fibrin glue derivative.
• YAG laser, Heimlich valves.
• Persistent air leak who is poor operative risk,could
be treated by using closed by pneumoperitoneum.
• Conclusion: If surgical treatment is going to be
necessary the sooner it is performed, the sooner
that patient can resume a routine life style.