Segment VII – Caudate process
Segmentum VII - Processus caudatus
Definition
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
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| Left medial | III | Segment III – Left medial hepatic lobe | Lobus hepatis sinister medialis | Left anterior lateral segment; Segment III
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| Central | Quadrate | IV | Segment IV – Quadrate lobe | Lobus quadratus | Left medial segment; Segment IV
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| Right medial | V | Segment V – Right medial hepatic lobe | Lobus hepatis dexter medialis | Anterior medial segment; Segment V
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| Papillary process | I | Segment I – Papillary process | Processus papillaris | Posterior segment; Caudate lobe; Segment I
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| Right | Right | Right lateral | VI VIa (dorsal) VIb (ventral) |
Segment VI – Right lateral hepatic lobe | Lobus hepatis dexter lateralis | Anterior lateral segment; Segment VI
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| Caudate process | VII | Segment VII – Caudate process | Lobus caudatus | Posterior lateral segment; Segment VII
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| Posterior medial segment; Segment VIII
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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.
References
