Segment IV – Quadrate lobe - Segmentum IV - Lobus quadratus

Description

In dogs the segmentation of the liver is described with four lobes and four sublobes as well as two processes, based on anatomical consideration. This nomenclature is used in the NAV.

For some authors, the use of a vascular anatomy of canine hepatic venous system based on the analogies between Couinaud’s segmentation of the human liver and the vascular anatomy of canine liver, could be less confounding and, therefore, more useful for the surgical (and also radiological) approach to this organ.

In vet-Anatomy, we used the publication of L. Mari and F. Acocella (1) to provide an hepatic segmentation of the dog: the canine liver lobes and human liver segments appear comparable so we use the terminology adapted from the human terminologia anatomica :

  

Section Division Lobe Segment Proposed nomenclature Conventional nomenclature in the NAV Equivalent segment in human
Left Left Left lateral

II

IIa (dorsal)

IIb (ventral)

Segment II – Left lateral hepatic lobe Lobus hepatis sinister lateralis

Left posterior lateral segment; Segment II

 

Left medial III Segment III – Left medial hepatic lobe Lobus hepatis sinister medialis

Left anterior lateral segment; Segment III

 

Central Quadrate IV Segment IV – Quadrate lobe Lobus quadratus

Left medial segment; Segment IV

 

Right medial V Segment V – Right medial hepatic lobe Lobus hepatis dexter medialis

Anterior medial segment; Segment V

 

Papillary process I Segment I – Papillary process Processus papillaris

Posterior segment; Caudate lobe; Segment I

 

Right Right Right lateral

VI

VIa (dorsal)

VIb (ventral)

Segment VI – Right lateral hepatic lobe Lobus hepatis dexter lateralis

Anterior lateral segment; Segment VI

 

Caudate process VII Segment VII – Caudate process Lobus caudatus

Posterior lateral segment; Segment VII

 

           

Posterior medial segment; Segment VIII

 

  

Note :

In the NAV, the caudate process and papillary process are included in a same lobe, the caudate lobe. But as these two processes differ by a right or left vascularization, they can’t be included in a same lobe in this hepatic segmentation, opposite to the human hepatic segmentation where the caudate lobe is the segment I and include the caudate process and the papillary process.

There is no segment VIII in the dog.

 

1 - Mari L, Acocella F. Vascular anatomy of canine hepatic venous system: a basis for liver surgery. Anat Histol Embryol. 2015 Jun;44(3):212-24. doi:10.1111/ahe.12129. Epub 2014 Aug 5. PubMed PMID: 25090952.


Text by Antoine Micheau, MD - Copyright IMAIOS

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