Venous circle of Trolard
Citation, DOI, disclosures and article data
At the time the article was created Francis Fortin had no recorded disclosures.View Francis Fortin's current disclosures
At the time the article was last revised Craig Hacking had the following disclosures:
- Philips Australia, Paid speaker at Philips Spectral CT events (ongoing)
These were assessed during peer review and were determined to not be relevant to the changes that were made.View Craig Hacking's current disclosures
The anastomotic venous circle of the base of the brain 1, also referred to as the venous circle of Trolard 2,3,5, is an inconsistently found venous homologue of the better-known arterial circle of Willis.
It should not be confused with other venous structures also described by Trolard such as the superior anastomotic vein of Trolard.
Although often incomplete and presenting variable anatomy, the venous circle is comprised of an anterior communicating vein joining the anterior cerebral veins, and a posterior communicating vein joining either the peduncular veins or the caudal portions of the basal veins of Rosenthal.
The posterior communicating vein is present in more than 75% of patients and courses in the interpeduncular fossa 4.
The circle is important insofar as it can be involved in vascular malformations and tumor drainage. On brain CT angiography acquired in a slightly late phase, it can be confused for arteries. It can also be a cause of erroneous spectral signal when interrogating the circle of Willis during fetal and neonatal Doppler 5.
History and etymology
The term "venous circle of Trolard" was recently coined 2 based on work in the late 1800s by Jean Baptiste Paulin Trolard (1842–1910), a French doctor and anatomist who studied the anastomotic veins of the brain 6. He also described the superior anastomotic vein of Trolard which carries his eponym 7.
Trolard worked between France and Algeria and was an advocate of public vaccination in Algiers, establishing a vaccination institute alongside Louis Pasteur. He was also a strong critic of deforestation for which he created the League of Reforestation of Algeria 7.