Chylothorax Flashcards
Anatomy of thoracic duct
- originates from cisterna chyli (T10-L3)
- enters thorax through aortic hiatus (T12)
- Course
- anterior to vertebral bodies (between Ao and azygous vein)
- posterior to esophagus
- Crosses midline to left: T4-5 (coursing to left of esophagus)
- Arches laterally at C7 (anteiror to SC artery, superficial to phrenic/anterior scalene)
- Passes behind carotid sheath and terminates into jugular-SC vein junction
- Single branch (80%)
- Multiple branches (20%)
Lymphatic drainage of right head, neck, chest wall, right lung, right heart, dome of liver, right diaphragm
Right lymphatic duct that drains into posterior junction of RIGHT jugular-SC junction
Primary physiologic role of the thoracic duct
Deliver digestive fat (60% of ingested fat) to the venous system
Main cellular component of thoracic duct lymph
T-lymphocytes
Properties of chyle
- Bacteriostatic
- alkaline pH
Normal rate of lymph flow
30-190 ml/hr
Mechanics of normal lymph flow
- Negative transdiaphragmatic pressure gradient
- Thoracic duct valves
- Normal intraductal pressure: 10-25 cmH2O
MCC of pleural effusion in neonatal period
Congenital Chylothorax
- Respiratory distress at birh or 1st weeks of life
- MOA:
- atretic thoracic duct
- multiple dilated lymphatic channels of fistulas
- Tx: conservative (self limited)
- Breastfeeding ok
- Thoracocentesis for inital relief
- Pleuroperitoneal shunting for persistent chylothorax (in absence of ascites)
MC non-penetrating traumatic MOA of thoracic duct injury
Hyperextension of the spine with rupture of thoracic duct just above the diaphragm
MC operations associated with surgical injuries to the thoracic duct
- Esophagectomy
- Aortic operations
- PDA ligation
- Left pneumonectomy
- Resection of posterior mediastinal tumors
- Sympathectomy
Laterality of duct injuries above (and below) T6
- Right side: below T6
- Left side above T6
Incidence of chylothorax after esophagectomy
0.5-3.5%
*no assocation with approach
MOA of neoplastic chylothorax
MC neoplasm associated with chylothorax
Invasion, compression or tumor embolism of thoracic duct
Lymphoma (50% of cases)
Most postoperative chylothoracies drain how much
Excess of 1L/day
*If persists for > 1 week, mortality and morbidity increased
Spontaneous healing of non-surgical thoracic duct fistula occurs __ %
< 50%