1. Chylothorax is defined as a collection of chyle in the pleural cavity resulting from a leak in the lymphatic vessels, usually from the thoracic duct which transports lymph from the body. 2. The thoracic duct anatomy is described, beginning near the kidneys and ascending through the diaphragm before crossing left and terminating near the subclavian vein. Damage to different parts of the duct can cause right or left-sided chylothorax. 3. Causes of chylothorax include traumatic injury, malignancy compressing vessels, and spontaneous/idiopathic cases. Diagnosis involves fluid analysis showing chylomicrons.

1. By
Mahmoud E. Abou El-Magd
Assistant lecturer of pulmonary and critical care medicine
CHYLOTHORAX
&
CHYLOPTYSIS

2. INTRODUCTION
CHYLOTHORAX 2
• Chylothorax is by definition a collection of chyle in the
pleural cavity resulting from leakage from the lymphatic
vessels, usually from the thoracic duct.
• approximately 2.5 L of chyle is transported through the
lymphatic system every day .

3. ANATOMY
CHYLOTHORAX 3
• The thoracic duct is approximately 3-45 cm
long and 2-3 mm wide.
• This typical pathway occurs in only 65% of
the population due to embryological variation
which may include multiple thoracic duct
branches.
• The thoracic duct drains the cisterna chyli, in
which the lymph from the lower half of the body
and the abdominal cavity joins the chyle coming
from the intestinal trunk, forming a mixture also
referred to as chyle.

4. COURSE OF THORACIC DUCT
4CHYLOTHORAX

5. CHYLOTHORAX 5
• Chyle passes from the intestinal lymphatics to cisterna chyli and
then through the thoracic duct to eventually empty into the
venous system.
• The thoracic duct begins at the cisterna chyli near the T-12
vertebra and ascends through the aortic hiatus of the diaphragm
on the anterior surface of the vertebral body between the aorta
and the azygos vein into the posterior mediastinum.
• At the level of the fifth thoracic vertebra, it then crosses to the
left of the vertebral column and ascends behind the aortic arch
to the left of the subclavian artery adjacent to the mediastinal
pleura.
•

6. CHYLOTHORAX 6
• At the level of the transverse process of the seventh cervical
vertebra, the duct turns laterally and runs anterior to the
vertebral and thyrocervical arteries and the sympathetic trunk.
Passing behind the carotid sheath,
• it descends anterior to the origin of the left subclavian artery and
terminates near the junction of internal jugular and subclavian
veins.
• A bicuspid valve at the lymphovenous junction prevents the
reflux of blood into the duct.

7. CHYLOTHORAX 7
• This duct carries lymph from the entire
body, except from the right side of the
head, neck, chest, both lungs, and the
right upper extremity that empties into the
right lymphatic duct.
• There are extensive anastomotic vessels
present between various lymphatics, and
numerous lymphaticovenous
anastomoses between the thoracic duct
and the azygos, intercostals, and lumbar
veins.
• The richness of this collateral circulation
allows the safe ligation of the thoracic
duct at any level

8. CHYLOTHORAX 8
• This anatomy explains why a chylothorax is usually
right-sided, since the largest part of the duct is within
the right hemithorax, and this is also where it is most
easily damaged due to stretching.
• When the leakage from the duct occurs where it passes
over the mid-line, a bilateral chylothorax can occur .
• At the level of the aorta, the chyle tends to appear on
the left side

9. PHYSIOLOGY
CHYLOTHORAX 9
• The chyle formed in the cisterna chyli is an odourless, white, opaque liquid.
• Analysis of chyle reveals approximately 90% lymphocytes and most of the
lymphocytes in chyle are T-lymphocytes.
• white cell count of 2,000 to 10,000 cells per cubic millimeter, which generally
renders this fluid bacteriostatic.
• because it is bacteriostatic and non- irritating, it does not cause
fibrothorax.

10. CHYLOTHORAX 10
• The primary role of the thoracic duct is to carry 60-70% of
ingested fat at a concentration of 0.5-6 g/dl from the intestine to
the circulatory system.
• As a result chyle contains large amounts of cholesterol,
triglycerides, chylomicrons and fat soluble vitamins.
• Lymph is the other main constituent of chyle and is made up of
immunoglobulins, enzymes .

11. PATHO-PHYSIOLOGY
CHYLOTHORAX 11
• When the duct starts to leak, a collection of chyle below the pleura, a
"chyloma", is at first formed but is only rarely seen clinically,.
• The formation of a "chyloma" can be a very dramatic clinical event, with
acute chest pain causing dyspnoea and tachycardia suggesting myocardial
infarction or pulmonary embolism. Such episodes seem to occur particularly
after traumatic rupture of the thoracic duct. Soon the pleura ruptures and the
chylus collects in the pleural space.
• There are some rare variations, for instance chylomediastinum, where the
chylus collects in the mediastinum without breaking through the pleura , or
chylopericardium, where it empties into the pericardial sac

12. CHYLOTHORAX 12
• Above the diaphragm an extrinsic obstruction or an infiltration of
the thoracic duct causes an increase in back pressure. This
elevated pressure promotes dilation of collateral channels and
renders lymphatic valves incompetent, which produces
regurgitant flow of chyle.
• seepage may occur through erosion or perforation of a
diseased thoracic duct or one of its tributaries into the
mediastinum. Mediastinal chyle then penetrates the mediastinal
pleura, producing a chylothorax; alternatively, leakage may
occur directly into the pleural space from the dilated
intrapulmonary lymphatics because of the regurgitant flow from
the broncho-mediastinal trunk or posterior intercostal
lymphatics.

13. CHYLOTHORAX 13

14. CHYLOTHORAX 14

15. CHYLOTHORAX 15

16. CHYLOTHORAX 16
• Traumatic cases can be further sub-classified as iatrogenic or
non-iatrogenic (20% of traumatic cases) with rupture even
described after coughing or vomiting episodes.
• Other iatrogenic traumatic causes include thoracic duct damage
following subclavian vein catheterisation and duct blockage due
to central venous catheterisation related venous thrombosis.
• Thoracic duct obstruction due to malignancy is the commonest
cause of non-traumatic chylothorax. Lymphoma is found in 70%
of cases (non-Hodgkin’s>Hodgkin’s). , Chylothorax can be the
first symptom of the lymphoma, and definite diagnosis is
sometimes not made until months or years later.

17. CHYLOTHORAX 17
• Mediastinal lymphadenopathy may compress the lymphatic
vessels preventing drainage of lymph from the lung periphery
resulting in extravasion of chyle in to the pleural space.
• Pulmonary lymphangioleomyomatosis is characterised by
proliferation of immature smooth muscle throughout the
peribronchial, perivascular, and perilymphatic region. It occurs
primarily in women of reproductive age and the perilymphatic
proliferation of smooth muscle results in lymphatic obstruction
and chylothorax in up to 50% of the patients.

18. CHYLOTHORAX 18
• A chylothorax may develop acutely without an underlying cause
and is referred to as spontaneous chylothorax.
• Idiopathic chylothorax is uncommon and comprises cases where
no underlying cause can be found.
• A sudden increase in duct pressure from coughing, especially
after a heavy meal when the duct is engorged, may be a
contributory factor.

19. CHYLOTHORAX 19

20. CHYLOTHORAX 20
• Respiratory difficulty as the pleural space fills with fluid.
• Patients may experience malnutrition due to the loss of protein, fats and
vitamins. Electrolyte loss can result in hyponatraemia and hypocalcaemia.
• Significant loss of immunoglobulins, T lymphocytes and proteins into the
pleural space results in immunosuppression.
• This immunosuppression predisposes the patient to opportunistic infections
although this almost never occurs in the effusion itself as chyle is
bacteriostatic.
• Drugs such as digoxin and amiodarone may become sub therapeutic as they
are lost through the leaking chyle.

21. CHYLOTHORAX 21
• The effusion may be unilateral, either right (50%) or left sided (33.3%), or
bilateral (16.66%) and is dependent on the location of the leak.
• Damage to the duct above the fifth thoracic vertebra results in a left sided
effusion whereas damage to the duct below this level leads to a right sided
effusion.
• Unusually rapid postoperative filling of the pneumonectomy space with fluid,
and mediastinal shift to the contralateral side ("tension chylothorax") are
suggestive radiographic findings
• Typically, thoracocentesis obtains a milky fluid, but this is seen in only about
half of all cases . Patients who are fasting (e.g., peri- or postoperative
patients) , so the effusion may appear serous or clear, or, after trauma, it
may be tinged with blood .

22. PSEUDOCHYLOTHORAX
CHYLOTHORAX 22
• A milky or creamy pleural fluid appearance may also be seen
in pleural empyema or so-called pseudochylothorax,
• Pseudochylothorax develops when an exudative effusion
remains in the pleural space for a long period of time (often
years) gradually becoming enriched with cholesterol.
• The most common aetiologies include tuberculous pleurisy,
chronic pneumothorax, rheumatoid pleurisy, poorly evacuated
empyema and chronic haemothorax.

23. CHYLOTHORAX 23
• turbidity is the result of high levels of cholesterol and not
chylomicrons. The effusion is usually of longstanding duration
and may cause thickened and even calcified pleura.
• The presence of cholesterol crystals in the fluid is diagnostic of
pseudochylothorax, and chylomicrons are never present on
lipoprotein analysis.
• Both chylous and pseudochylous fluid remain opaque after
centrifugation.
• whenever there is any doubt, the fluid should be analysed for
chylomicrons.

24. CHYLOTHORAX 24

25. CHYLOTHORAX 25

26. CHYLOTHORAX 26
• Investigation of suspected chylothorax begins with the
confirmation of the diagnosis by fluid analysis.
• identification of the leakage point where possible.
• In non-traumatic cases CT abdomen and thorax should be
performed given the strong association with malignancy . This
may demonstrate evidence of tumour or lymphadenopathy.
• Lymphangiography may be used to demonstrate the site of
leakage or blockage.

27. CHYLOTHORAX 27
• Chylothorax can be differentiated from empyema by performing
centrifugation where the fluid remains uniform unlike the clear
supernatant that develops in empyema.
• Chylothorax can be differentiated from pseudochylothorax by
adding 1-2 ml of ethylether. The milky appearance disappears in
pseudochylothorax.
• The exact diagnosis of chylothorax is based on the presence of
chylomicrons in the pleural fluid.

28. CHYLOTHORAX 28
• Chylomicrons are molecular complexes of proteins and lipids
that are synthesised in the jejunum and transported via the
thoracic duct to the circulation.
• They are only found in the circulation postprandially with a peak
3 h after eating.
• In centres with available facilities. lipoprotein analysis
demonstrating chylomicrons is the gold standard. Where this
facility is not available, institutions rely on the measurement of
fluid cholesterol and triglyceride levels.

29. CHYLOTHORAX 29
• Staats et al. introduced criteria for the biochemical diagnosis of chylothorax
in 1980.They noted that a pleural fluid triglyceride of >110 mg/dl had a 1%
chance of being non-chylous and that a triglyceride of <50 mg/dl had a 5%
chance of being chylous.
• As a result, pleural fluid triglyceride levels> 110 mg/dl with a cholesterol< 200
mg/dl is diagnostic of chylothorax.
• A triglyceride level < 50 mg/dl with a cholesterol> 200 mg/dl is found in
pseudochylothorax. Cholesterol crystals are also often seen in this
condition.
• A triglyceride level can be low in fasting patients .
• triglyceride concentration <50 mg/dL almost rules out chylothorax.

30. CHYLOTHORAX 30
• Chyle is also alkaline with a specific gravity of greater than 1.012 and will
settle on standing with a fat-rich portion on the top and a cellular sediment on
the bottom.
• In cases where the triglyceride level is above the criteria set for
pseudochylothorax but below those for chylothorax (55-110 mg/dl),
lipoprotein analysis is required to confirm or exclude a diagnosis of
chylothorax.
• A fluid to serum cholesterol ratio<1 and triglyceride ratio>1 are also found in
chylothorax.
• Most cases of chylothorax are exudative (high protein, low lactate
dehydrogenase [LDH]), but in about 25% of cases it can be transudative.

31. CHYLOTHORAX 31
• Typical chylus effusions are lymphocyte predominant - protein
discordant exudates with triglyceride levels> 110 mg/dl and presence
of chylomicrons .
• transudative chylothoraces have been described in cirrhosis and
nephrotic syndrome.
• Cirrhosis related chylothorax results from ascites induced raised
intra-abdominal pressure leading to functional obstruction of the
thoracic duct.
• Other well described causes of transudative chylous effusion include
radiotherapy for Hodgkin’s disease, cardiac failure and constrictive
pericarditis.

32. CHYLOTHORAX 32
• Basically, a leak can be located non-invasively using
radionuclides or magnetic resonance imaging .
• Lymphography can also demonstrate a leak, but as the only
invasive procedure is rarely indicated nowadays

33. CHYLOTHORAX 33
• Radionuclide lymphoscintigram
and contrast lymphangiogram
demonstrating a leak in the left
upper mediastinum.

34. CHYLOTHORAX 34

35. CHYLOTHORAX 35
• patient who persistently loses chyle will be losing considerable
amounts of fat and fat-soluble vitamins, proteins (chyle
contains 12–60 g/L, depending on nutritional intake),
electrolytes, immunoglobulins, and T-lymphocytes, with resulting
malnutrition, weight loss, and an impaired immune system
• After only 8 days of T-cell depletion due to external chyle
drainage, patients are already at risk of septicemia .

36. CONSERVATIVE TREATMENT
CHYLOTHORAX 36
• The cornerstones of treatment are adequate fluid and
electrolyte replacement along with appropriate nutrition.
• treatment of the underlying disease, or clinical symptoms are
present that only require occasional aspiration.
• Repeated thoracocentesis is usually only performed when
improvement is expected from short-term , Otherwise, in
patients with high-volume or, especially, symptomatic
chylothorax, continuous drainage is put in place to allow the
lung to re-expand and to optimize pulmonary function

37. CHYLOTHORAX 37
• complete parenteral nutrition has in many places become
established as the first step
• Generally, the success rate of conservative treatment ranges
from 16% to more than 75%
• at output rates of more than 1000 mL/day, the success rate of
conservative treatment is low
• Chest tube drainage of less than 500 mL during the first 24
hours aftar complete oral intake cessation and total parenteral
nutrition may predict successful conservative treatment.

38. CHYLOTHORAX 38

39. CHYLOTHORAX 39
SOMATOSTATIN
• Neither chylothorax as an indication nor the dose, method, and duration of
drug administration have been confirmed or standardized in pro -spective
studies .
• If a drain output that has previously remained unchanged halves within 48
hours of the start of additional octreotide administration, this suggests that the
reatment is working and the drug should therefore be continued .
• Somatostatin is an inhibitor of gastric, pancreatic, and intestinal secretions,
thereby helping to keep the gastrointestinal tract empty, which in turn
decreases the chyle production.

40. CHYLOTHORAX 40
OCTREOTIDE
o Octreotide is an analog of somatostatin but longer half-life, it
offers a subcutaneous as well as intravenous route of
administration
o 50 mcg SC q8hr initially; titrate up to 500 mcg SC q8hr if
necessary .
o It also suppresses gastrointestinal hormones including gastrin,
motilin, secretin, and pancreatic polypeptide as well as
decreasing splanchnic blood flow.
o Octreotide is a potent inhibitor of insulin.

41. CHYLOTHORAX 41
• Primary side effects include suppression of GIT motility and
secretion (loose stools, malabsorption, nausea and flatulance).
• Other side effects such as cutaneous flush, transient
hypothyroidism, elevated liver function tests .

42. CHYLOTHORAX 42

43. CHYLOTHORAX 43
• Midodrine (ProAmatine) is a readily available, oral, selective
alpha adrenergic drug used in treating orthostatic and
hemodialysis induced hypotension
• Case reports suggest Etilefrine as an adjunct treatment of
postoperative chyle leaks.
• Etilefrine is a sympathomimetic drug with αlpha and β
adrenergic properties used to treat postural hypotension. which
cause smooth-muscle contraction, resulting in reduced
diameter of the lymphatic vessels. may lead to decreased chyle
flow and augment spontaneous closure of the chyle leaks.

44. CHYLOTHORAX 44

45. CHYLOTHORAX 45

46. CHYLOTHORAX 46

47. CHYLOTHORAX 47

48. SURGICAL TREATMENT
CHYLOTHORAX 48
Operative treatment was and is regarded as indicated when :
●More than 1000–1500 mL chyle is being drained every day .
●For 5 treatment days drain output is up to 1000 mL/day.
●A leak persists for more than 2 weeks (100 mL/day >2 weeks)
●Clinical deterioration occurs, e.g., malnutrition or metabolic
problems

49. CHYLOTHORAX 49

50. PLEURODESIS
CHYLOTHORAX 50
• If an operation has failed, or if thoracic duct ligation does not
appear feasible or worthwhile, pleurodesis may heal the
chylothorax .
• Pleurodesis also offers a treatment option when a malignant
tumor is the cause of the chylothorax.
• It must be borne in mind that pleurodesis can only be
successful in patients with expandable lungs (i.e., nontrapped
lungs)

51. CHYLOTHORAX 51

52. CHYLOTHORAX 52

53. INTERVENTIONAL RADIOLOGY
CHYLOTHORAX 53
• Today there are several radiological treatments that can be used
in both traumatic and non-traumatic chylothorax .
• Much more experience is available for percutaneous
embolization of the thoracic duct , which can be performed as
an alternative to thoracic duct ligation and can be performed in
both adults and children .
• Embolization has a much higher success rate: if the thoracic
duct can be intubated successfully, the procedure is successful
in well over 90% of cases

54. CHYLOTHORAX 54

55. CHYLOTHORAX 55

56. CHYLOTHORAX 56

57. CHYLOTHORAX 57

58. CHYLOTHORAX 58

59. CHYLOTHORAX 59

60. CHYLOTHORAX 60

61. CHYLOTHORAX 61

62. CHYLOTHORAX 62
• Chyloptysis is expectoration of milky-white sputum rich in chyle
• Chyloptysis is a rare finding, and the accompanying respiratory symptoms
are usually nonspecific. The recognition of the chylous nature of the sputum
is requisite for proper diagnosis, especially if chyloptysis is not accompanied
by chylous pleural effusion.
• The key to the differential diagnosis of chyloptysis is to consider illnesses
that can induce reflux of chyle into the bronchial tree.
• There are two mechanisms postulated: the first requires the presence of an
abnormal communication between the bronchial tree and the lymphatic
channels, and the second requires a bronchopleural fistula in the context of
a chylous pleural effusion.

63. CHYLOTHORAX 63
• Chyloptysis can also occur if the thoracic duct is not patent from
agenesis, tumor obstruction, or trauma.
• When the peribronchial lymphatics are subjected to a circulatory
overload of chyle plus lymph fluid from the lungs, the
overloaded peribronchial pulmonary lymphatics become dilated
and engorged.
• may herniate through the bronchial mucosa and may rupture
into the bronchial lumen producing chyloptysis.

64. DIFFERENTIAL DIAGNOSIS OF
ISOLATED CHYLOPTYSIS
CHYLOTHORAX 64

65. CHYLOTHORAX 65
• The production of chylous sputum may be intermittent and is not
always postprandial, nor is it always associated with fatty food
intake.
• Aside from cholesterol and triglyceride determination, lipoprotein
electrophoresis may be of value in confirming the chylous
nature of the sputum

66. SPECIMEN HANDLING IN SUSPECTED
CHYLOPTYSIS
CHYLOTHORAX 66
• Collect specimen in early morning
• Photograph sample if possible
• Sputum in sample container should be put in “wet ice”
• Order cholesterol, triglyceride, and lipoprotein
electrophoresis if available
• Notify laboratory that specimen is coming , Run the
analysis as soon as possible

67. CHYLOTHORAX 67

68. CHYLOTHORAX 68

69. CHYLOTHORAX 69
• The most frequent causes of chylothorax today are surgery and
tumors.
• Clinically, chylothorax manifests non-specifically as a pleural
effusion, typically with a triglyceride content of over 110 mg/dL.
The diagnosis is confirmed by demonstrating the presence of
chylomicrons in the aspirate.
• As a rule, conservative treatment is tried first. The aim is to
bring about spontaneous closure of a lymph leak by reducing
the flow of lymph

70. CHYLOTHORAX 70
• If conservative treatment fails, the next option to consider is
surgery. This may be in the form of, for example, thoracic duct
ligation, pleurodesis, or placement of a pleuroperitoneal shunt.
• Other alternatives available today are interventional radiological
procedures such as percutaneous thoracic duct embolization.
• Individual case management is determined by the clinical
situation and local availability of the various treatment options,
since no prospective studies are available as a basis for
guidance

71. CHYLOTHORAX 71