Cisterna chyli
Cisterna chyli
Also known as: chyle cistern, receptaculum chyli, abdominal confluence of lymph trunks
A thin-walled, dilated lymph sac on the posterior abdominal wall at about L1–L2 that receives the lumbar and intestinal trunks and gives rise to the thoracic duct.
Overview
The cisterna chyli is the dilated lower end of the thoracic duct — an elongated, often fusiform sac a few centimetres long lying on the anterior surfaces of the bodies of L1–L2 (range ≈ T10–L3), posterior and to the right of the abdominal aorta, behind the right crus of the diaphragm and close to the origin of the azygos vein. It collects lymph from the whole of the body below the diaphragm: the two lumbar trunks and the intestinal trunk (often with the descending intercostal trunks from the lower intercostal spaces).
Its form is very variable: in many people a discrete sac is not present and is replaced by a plexus of dilated lymphatic channels or a simple confluence of trunks. Because it receives intestinal lymph, it contains milky chyle after a fatty meal, from which it takes its name. It passes upwards through the aortic hiatus (T12) to continue as the thoracic duct.
- Location
Retrocrural/retroperitoneal, anterior to L1–L2 vertebral bodies, between the abdominal aorta (to its left) and the right crus of the diaphragm/azygos vein.
Anatomy
- Tributaries
Right and left lumbar lymphatic trunks; intestinal trunk; descending thoracic (intercostal) lymph trunks.
- Relations
Anterior: right crus of diaphragm; left: abdominal aorta; right: azygos vein and right crus; posterior: L1–L2 vertebral bodies and right lumbar arteries.
- Development
Develops from the retroperitoneal lymph sac region dorsal to it; one of the original six lymph sacs, the only one not invaded by lymph-node-forming mesenchyme in its upper part.
Function
- Collects lymph from the lower limbs, pelvis, abdominal wall and abdominal viscera (including chyle) and delivers it to the thoracic duct.
Clinical significance
Imaging and intervention
A prominent cisterna chyli can mimic a retrocrural lymph node or mass on CT/MRI (it is fluid-filled and tubular). It is the target for percutaneous access in thoracic-duct embolisation for refractory chylothorax.
Test yourself
Which lymphatic trunks drain into the cisterna chyli?
- Jugular and subclavian trunks
- Bronchomediastinal trunks
- Lumbar and intestinal trunks
- Right and left subclavian trunks
Answer: Lumbar and intestinal trunks
The paired lumbar trunks (lower limbs, pelvis, kidneys, posterior abdominal wall) and the single intestinal trunk (GI tract) converge on the cisterna chyli at ≈ L1–L2, the origin of the thoracic duct.
Compiled from standard anatomy and physiology references — see the Lymphatic & Immune System sources. For education only; not medical advice.