The Pleura
1. Anatomy
A. Parietal and Visceral pleura
B. Potential space
C. Histology
D. Arterial supply
1) Parietal
2) Visceral
E. Lymphatic drainage
2. Physiology
A. Mechanics
1) Negative pleural pressure
B. Fluid movements
1) Visceral
2) Parietal
3) Lymphatics
3. Video Assisted Thoracotomy
A. Indications - Diagnosis
1) Undiagnosed pleural effusion
2) Pleural based lesion
3) Tumor staging and diagnosis (biopsy)
4) Evaluation of thoracic injury
4. Indications - Therapeutic
A. Pneumonolysis
B. Foreign body extraction
C. Pleurodesis
D. Debridement of empyema cavity
E. Control of hemorrhage
F. Clot evacuation
G. Sealing of pneumothorax
5. Malignant Pleural Effusion
A. Diagnosis
1) Pathophysiology
2) Fluid characteristics
a) Appearance
b) Chemistry (exudate)
(1) Protein > 3 g/dl; LDH > 200 u
(2) pH < 7.3; glucose < 60 mg/dl
(3) Amylase > 160 u
c) Cytology, Histology
d) V.A.T.S.
6. Malignant Pleural Effusion
A. Management
1) Repeated thoracentesis
2) Chest tube drainage with intrapleural sclerosis
a) Empty pleural space
b) Expandable lung
c) CT output < 150 - 200 cc/day
3) Pleurectomy
4) Miscellaneous
a) Shunts, XRT
b) Hormonal therapy, chemotherapy
7. Mesotheliomas
A. Benign Localized
1) Asbestos - no; asymptomatic
2) Extra-thoracic - 1/3
3) Resection
B. Malignant Localized
1) 20% primary malignant pleural tumors
2) Localized, symptomatic
3) Wide en bloc excision
C. Diffuse Malignant
1) 0.8-2.1/million/yr
2) 50% - pure epithelial; 30% - mixed
3) Asbestos - yes; smoking - no
8. Diagnosis
A. Middle-aged men, symptomatic, asbestos
B. CXR, CT scan
C. Biopsy: Keratin (+), CEA (-), hyaluronic (+)
D. Management
1) Supportive care
2) Debulking with subtotal pleurectomy
3) Radical surgery
4) XRT, chemotherapy
E. Prognosis
1) Median survival 6-14 months
9. Chylothorax
B. Anatomy of the duct - main and right
C. Mechanics of lymph flow
D. Chyle
1) 1500 - 2400 cc/day
2) Triglyceride 0.4-0.6 g/dl
3) AG ratio 3:1
4) WBC 2,000-20,000 cells/ml (90% T)
E. Congenital, traumatic, non-traumatic
10. Diagnosis
A. R > L
B. Pleural effusion analysis
C. Pseudochyle
D. Management
1) Non-operative: Drainage, dietary management
2) Non-traumatic
3) Traumatic
a) Surgery if > 1,000 cc/day X 7 days or leak > 2 weeks
b) Esophageal resection or pneumonectomy
c) Lung trapped, nutritional complications
d) Direct ligation of fistula, duct ligation
EXTENDED OUTLINE
1. Usual causes:
A. contamination of pleural space
B. imbalance in the dynamic equilibrium with fluid accumulation
C. mesothelioma
2. Anatomy
A. mesothelial cells
B. parietal/visceral components
C.Blood supply
1) parietal—systemic>>intercostal, bronchial, and subclavian arteries
a) venous drainage into the peribronchial veins
2) visceral—systemic and pulmonary circulations
a) venous drainage into the pulmonary venous system
D. Lymphatic system—two systems
1) visceral—pulmonary system (lower lobes)
2) parietal—direct communications with the pleural space—stomata
3. Physiology
A. pleural pressure is essentially negative during the breathing cycle—at FRC, pressure is –2 to –5 cm H2O; full inspiration –25 to –35 cm H2O
B. more negative at the apex than the base
C. Fluid—200cc to 1L absorbed Q24 hours
1) Composition
4. Management of pleural diseases
A. Spontaneous pneumothorax
1) Peripheral lung bleb is the usual cause
B. usually seen in tall thin individuals
1) pathogenesis of lung blebs is unknown
a) ? rapid lung growth relative to the pulmonary vasculature
b) ?higher transpulmonary pressure at apex—increased alveolar pressure
2) acute pleuritic chest pain common symptom
3) physical exertion is unrelated to occurrence
C. Management
1) observation if small –air resorbed at 50-75ml/day
2) supplemental oxygen
3) tube thorocostomy for
- moderate sized or tension PTX
- disease in the contralateral lung
- persisting symptoms
- progression of size
- Hemothorax quite uncommon—torn adhesion usual cause
- Indications for surgery for first episode PTX:
D. Risk factors for recurrence:
1) about 20% recur
a) 75% recur on the same side within 2 years of the first episode
b) when a surgical procedure is required, two principals are important:
2) removal of the offending blebs
3) production of pleural symphysis
a) axillary thoracotomy (3rd interspace) or VAT
b) pleurodesis achieved via talc or doxycycline—do not use talc in young patients or those with CF because the adhesions formed preclude lung transplantation
E. Secondary spontaneous pneumothorax
1) seen mostly in older people with documented lung disease
2) predominant symptom is severe SOB—not chest pain
3) initial tx—tube thorocostomy
4) prolonged air leak common
5) recurrence rate—50% after one episode; therefore people with a reasonable operative risk should have definitive treatment
F. Empyema
1) purulent pleural effusion with (+) bacteriologic cultures
G. Post traumatic empyemas
1) penetration of the chest wall—foreign material carried into the pleural space
2) presence of a hemothorax—becomes secondarily infected from a chest tube
H. Stage I-parapneumonic effusion
I. Stage II-fibrinopurulent phase; (+) bacterial invasion
J. Stage III-chronic phase; ingrowth of fibroblasts and capillaries; thick peel
1) Complications most likely, e.g., empyema necessitatis-dissection of pus through the soft tissues of the chest wall and eroding through the skin
K. Diagnosis—fever, tenderness
1) posterior and lateral—extend to the diaphragm
2) CXR: inverted D-shaped density on the lateral chest film
3) most common organisms: S. aureus, G(-) bacteria, and anaerobes; almost 50% are polymicrobial
4) effusions with pH <7, glucose <50, LDH >1000, should be drained
L. Management
1) Complete drainage of the collection
2) Obliteration of the empyema space
3) Investigation and treatment of the underlying infection
4) Management of associated conditions
M. Decortication-goal is full lung expansion—via extensive debridement
1) early aggressive approach—as soon as tube thorocostomy is ineffective
N. Eloesser Flap—long term drainage of empyema
1) Removal of chest tube tract and carrying the incision down to the ribs
2) Two ribs and the intervening intercostal muscles are removed
3) Skin sutured to the pleura—dependant drainage insured
O. Clagett procedure—open window thorocostomy excision of the sinus tract instillation of antibiotics in the pleural cavity, closure of the chest wall described for
post-pneumonectomy empyema best results (25-60%) when no bronchopleural fistula present
Streptokinase
P. Persistence of empyema usually is secondary to inadequate drainage chronic pulmonary disease (TB, Fungus, Neoplasm) immune suppression foreign body In summation for chronic empyema:
1) Tube thorocostomy
2) Thorocoscopy/open decortication
3) Eloesser flap
4) Thoracoplasty/Muscle transposition
4. Malignant pleural effusions
A. due to a disturbance in the equilibrium of production and absorption of fluid
B. lymphatic obstruction esp. with paraneoplastic effusions
5. Management—palliation/relief of symptoms (usually dyspnea) is the goal—removal of effusion
A. options—pleurectomy; mechanical pleurodesis; talc poudrage; pleuroperitoneal shunt; tube thorocostomy and sclerosis
6. Mesothelioma
A. Benign localized unassociated with asbestos exposure asymptomatic--detected on routine CXR paraneoplastic syndromes common
1) well-encapsulated visceral pleural masses
B. Malignant localized 20% symptomatic wide enbloc excision adjuvant therapy of little value
C. Malignant diffuse asbestos exposure with latency period of 20 years
intensity of exposure more important than duration.usual patient is middle aged male with pleuritic chest pain/SOB CXR shows pleural calcifications
1) three main types—epithelial (confused with adenocarcinoma), mesenchymal, and mixed
median survival 6 to 14 months--most die of local complications subtotal pleurectomy—1 year survival—60% radical extrapleural pneumonectomy
2) adjuvant chemotherapy
D. Chylothorax—results from thoracic duct obstruction Anatomy of thoracic duct--50% of the population originates form the cisterna chyli—T12-L2
1) Right posterior mediastinum between azygous, esophagus, and aorta
2) Tracheal bifurcation, crosses to left chest
E. Neck-anterior to scalene muscle and enters venous system at jugular/subclavian junction Physiology—upward flow secondary to pressure gradient, fat intake, contraction of the duct, and the presence of valves
1) 1.5-2.5 L/day
2) odorless with high triglyceride count, total protein, WBC (T-Cell)
F. Etiology
G. Diagnosis—chylomicrons
1) Pseudochyle
H. Management--Non-operative (tube thorocostomy/thoracentesis) for non traumatic
1) Diet—medium chain triglycerides—reduce lymph flow
2)Traumatic—operate if >1L/day for 7 days or leak > 2 weeks
3) Children >100ml/day per year of age for 2-3 weeks
4) Operate if lung entrapped or nutritional complications
I. Technique-direct ligation of the fistula [heavy cream]
1) Subdiaphragmatic duct ligation—right thoracotomy; mass ligature of the tissue between the azygous and aorta
5. Thoracoplasty
A. Thoracoplasty for TB-historic approaches attempted to copy nature’s intentions, i.e., resection of the chest wall to collapse the underlying diseased lung.
B. Most successful was 3 stage approach by Alexander 75% sputum conversion
multiple pulmonary complications frozen shoulder” cosmetically unacceptable results
C. Schede
D. Plombage-introduced in the 1950’s
1) Various materials placed extrapleurally between the lung and ribs or extraperiostally
E. Did not interfere with cough or chest wall movement complicated by infection
60% conversion rate.
F. Osteoplastic thoracoplasty posterior ends of the upper ribs are resected in increasing lengths back to the tip of the transverse processes which are left intact
ribs are reflected down posterior ends are wired to the uppermost intact rib
chest wall stability.
G. Muscle transposition into chronic empyema cavity. Can also be done as a free flap