1st-order division anatomy: livers/hemilivers/lobes 2nd-order division anatomy:sections/sectors 3rd-order division anatomy: segmental 4th-order division anatomy: subsegmental

1. Liver anatomy / terminology
In brief
Raimundas Lunevicius
Consultant Surgeon
Liverpool University Hospitals NHS FT, Aintree site
University of Liverpool
19th July 2018

2. Aim
Terminology: use the same medical
language

3. MEDICAL LANGUAGE
for liver anatomy
• Ideal: one medical language, to be precise
• Reality: it is not the case
• Know historic & modern terminologies

4. The terminology to describe anatomy of liver injury
Most common classifications of the anatomical
units of the liver:
• Couinaud’s (1952) liver anatomy system
• Healey & Schroy’s (1953) liver anatomy system
• Brisbane system (2000)

5. Classical names of 5 ligaments in Latin
and the longest imaginary plain of the liver
• Ligaments and structures inside (in Latin):
– Lig. teres hepatis
– Lig. falciforme hepatis
– Lig. coronarium hepatis
– Lig triangulare dextrum
– Lig. triangulare sinistrum
• Rex – Cantlie plain (not line)

6. Healey & Schroy
classification and nomenclature
• Lobes: 2
• Segments: 4
• Subsegments: 8
• The planes: 3
– The main portal fissure
– The right portal fissure
– The umbilical fissure

7. Couinaud’s
classification and nomenclature
• Livers: 2 (not lobes)
• Sectors: 5 (not segments)
• Segments: VIII (not subsegments)
• Subsegments: not specified as a subsegment
is a piece of the liver less than segment
• Planes: 3
– The main portal fissure
– The right portal fissure
– The left portal fissure (not ‘the umbilical fissure’)

8. Brisbane
classification and nomenclature
• Hemilivers: 2 (not lobes, not livers)
• Sections: 4 (not segments, not sectors)
• Segments: 9 (not subsegments)
• First-order division anatomy
• Second-order division anatomy
• Third-order division anatomy
(Fourth-order division anatomy: not included into Brisbane)

9. Anatomical divisions of the liver:
summary of terms
1st-order division anatomy: livers/hemilivers/lobes
2nd-order division anatomy:sections/sectors
3rd-order division anatomy: segmental
4th-order division anatomy: subsegmental

10. Nomenclature for first-order division
anatomy (hemilivers) and resections: Brisbane
the watershed is the midplane of the liver (Rex-Cantlie ‘line’)
Anatomic term Couinaud
segments
Term for resection Diagram
Right hemiliver
OR
Right liver
Sg 5–8 (± Sg1) Right hepatectomy OR
Right hemihepatectomy
(± Sg1)
Resection 5–8
Left hemiliver
OR
Left liver
Sg 2–4 (± Sg1) Left hepatectomy OR
Left hemihepatectomy
(± Sg1)
Resection 2–4

11. Nomenclature for second-order division
anatomy (sections) and resections: Brisbane
the watersheds: right and left (umbilical fissure – attachment of the falciform ligament) intersectional planes
Anatomic term Couinaud
segments
Term for resection Diagram
Right anterior
section
Sg 5,8 Right anterior
sectionectomy
Right posterior
section
Sg 6,7 Right posterior
sectionectomy
Left medial section Sg 4 Left medial
sectionectomy
OR
Resection segment 4
OR
Segmentectomy 4
Left lateral section Sg 2,3 Left lateral sectionectomy
OR
Segmentectomy 2,3

12. Nomenclature for third-order division
anatomy (segments) and resections: Brisbane
for clarity Sg 1 and 9 are not shown; the watersheds of segments are intersegmental planes
Anatomic term Couinaud
segments
Term for
resection
Diagram
Segments 1–9 Any one of Sg 1 to
9
Segmentectomy 6
Two contiguous
segments
Any two of Sg1 to 9
in continuity
Bisegmentectomy
5,6

13. Nomenclature of resections of three sections
Couinaud
segments
Term for
resection
Diagram
Sg 2–5,8 (Sg ± 1) Left
trisectionectomy
Sg 4 – 8 (Sg ± 1) Right
trisectionectomy

14. FORTH-ORDER DIVISION ANATOMY:
Brisbane classification does not cover

15. FORTH-ORDER DIVISION ANATOMY (subsegmental division),
by Nagoya university, Japan (thank you dr. Kamiya)
17 subsegments, at least, or more (ie19) as 4D and 8D have been later described
(S1 excluded: it has two lobes – right and left)
Thank you