# Couinaud — Couinaud liver segmentation with Brisbane terminology

> Localizes liver parenchyma by portal territories and intersegmental hepatic-vein planes into segments I-VIII, with segment IV optionally resolved as IVa and IVb.

**Situação:** vigente · **Órgão:** Fígado · **Órgão emissor:** Couinaud / IHPBA · **Versão:** Classic 8-segment model / Brisbane 2000 terminology · **Ano:** 1957

> ⚠️ Uma versão mais nova pode existir (em revisão).

## Procedência e vigência
- Família: léxico
- Tipo de lógica: flat
- Modalidade: CT, MRI
- Fonte primária: Strasberg SM, Belghiti J, Clavien PA, Gadzijev E, Garden JO, Lau WY, Makuuchi M, Strong RW. The Brisbane 2000 Terminology of Liver Anatomy and Resections (2000) — https://doi.org/10.1016/S1365-182X(17)30755-4
- Última verificação: 2026-07-24
- Última checagem: 2026-08-12

## Lógica de decisão
Assign vascular territories, not just clock-face positions. Preserve multiple involved segments, anatomy variants, uncertainty, and the distinction between anatomic localization and treatment planning.

## Categorias

| Código | Rótulo | Critérios | Conduta | Risco | Localizador | Verificado |
| --- | --- | --- | --- | --- | --- | --- |
| I | Segment I (caudate) | Caudate territory dorsal to the main portal pedicle and adjacent to the retrohepatic IVC. Segment I commonly receives portal pedicles from both right and left sides and drains directly to the IVC through short hepatic veins. | Report the caudate relationship to the IVC, short hepatic veins, portal pedicles and hilum when intervention is contemplated. Under Brisbane terminology, explicitly add 'with resection of segment 1' or 'extended to segment 1' when it accompanies another named resection. | The I code has no biological prognosis. Its direct IVC drainage and dorsal vascular relationships can affect technical planning, but they do not provide a quantified operative or ablation-risk category. | Couinaud 1999, PMID 10805544, portal plus suprahepatic segmentation; Anatomy of Hepatic Resectional Surgery, PMC4994882, Couinaud segments text and Fig 7; Brisbane context in PMC4786552, segment-1 naming rule. | ✓ |
| II | Segment II (left lateral, superior) | Superior left-sided segment above the transverse left portal plane. In original Couinaud sector terminology II is the left posterior sector; in Brisbane terminology it joins III as the left lateral section, lateral to the falciform/umbilical-fissure division. | Use II for the demonstrated segmental portal territory and state if a lesion crosses into III, IV or I. II plus III constitutes a Brisbane left lateral sectionectomy; a segment number alone does not establish resectability or select an operation. | Segment II carries no intrinsic oncologic or procedural-risk score. Risk depends on lesion extent, vascular and biliary relationships, access, liver reserve and the planned intervention. | IHPBA Brisbane 2000 consensus, DOI 10.1016/S1365-182X(17)30755-4, second- and third-order divisions; PMC4994882, Couinaud segments and Brisbane terminology; PMC4786552, Figs 1-2. | ✓ |
| III | Segment III (left lateral, inferior) | Inferior left-sided segment below the transverse left portal plane. Brisbane groups III with II as the left lateral section, whereas original Couinaud sector terminology groups III with IV in the left anterior or paramedian sector. | Report III from its portal territory and preserve any extension into II, IV or the hilum. II plus III is a Brisbane left lateral section; do not use the original left sector and Brisbane left section names interchangeably. | Segment III is an anatomic location, not a prognosis. The segment label does not quantify surgical morbidity, safe ablation margin, liver-remnant adequacy, or tumor behavior. | IHPBA Brisbane 2000 consensus, second-order left lateral section and third-order segment terminology; PMC4994882, Couinaud segments text explaining the original II versus III/IV sectors and Brisbane II/III versus IV sections. | ✓ |
| IV | Segment IV (left medial, whole or level unresolved) | Whole left medial segment or segment IV involvement for which a superior-versus-inferior subdivision is not resolved. Brisbane places IV between the functional midplane on the right and the falciform/umbilical-fissure division on the left; it can be subdivided into IVa and IVb. | Return IV when the whole segment is involved or IVa/IVb cannot be assigned confidently; otherwise use the resolved subsegment. Describe proximity to the middle hepatic vein, hilar plate, left portal pedicle and bile ducts rather than treating IV as a complete planning statement. | IV conveys location only. Central vascular or hilar relationships may change technical complexity, but the parent code provides no calibrated procedural, liver-failure, or oncologic risk. | Brisbane 2000 consensus, left medial section and segment nomenclature; PMC4994882, Couinaud segments and Brisbane terminology, including variable IVa/IVb branching; PMC4786552, segment-oriented planning context. | ✓ |
| IVa | Segment IVa (left medial, superior) | Superior subdivision of segment IV, above the transverse portal plane within the Brisbane left medial section. IVa/IVb separation follows left portal-pedicle branching and may be indistinct or variable. | Use IVa only when the superior portal territory can be supported on imaging; otherwise retain IV and state uncertainty. Report middle-hepatic-vein, hilar, portal and biliary relationships for intervention planning. | IVa has no independent biological prognosis or validated technical-risk class. Posterosuperior position and vascular relationships must be described directly rather than inferred from the code. | PMC4994882, Couinaud segments text and Fig 5: segment IV may be divided into IVA superiorly and IVB inferiorly, with variable branching; Brisbane 2000 consensus for left medial-section terminology. | ✓ |
| IVb | Segment IVb (left medial, inferior) | Inferior subdivision of segment IV, below the transverse portal plane within the Brisbane left medial section. It corresponds to the inferior medial left-liver territory and includes the quadrate region in conventional surface anatomy. | Use IVb only when the inferior portal territory is resolved; otherwise retain IV. Report relationships to the gallbladder fossa, hilum, segmental portal and biliary branches, and middle hepatic vein when relevant to planning. | IVb is an anatomic descriptor without a calibrated prognosis. Proximity to hilar, biliary or vascular structures is more informative for technical risk than the segment label itself. | PMC4994882, Couinaud segments text and Fig 5 (IVB inferior to the left portal plane and variable subdivision); Brisbane 2000 consensus, left medial section. | ✓ |
| V | Segment V (right anterior, inferior) | Inferior segment of the right anterior section, generally between the middle- and right-hepatic-vein planes and below the transverse right portal plane. V pairs with VIII in the Brisbane right anterior section. | Report V plus any extension across the middle hepatic, right hepatic or transverse portal boundaries. V with VIII forms the right anterior section, but location alone does not determine sectionectomy, ablation, or resectability. | Segment V has no inherent malignancy or procedural-risk value. Actual risk depends on vascular and biliary proximity, lesion size and extent, liver reserve, and the proposed intervention. | Couinaud 1999, portal and hepatic-vein segmentation; Brisbane 2000 consensus, right anterior section; PMC4994882, Couinaud segments text (V inferior, VIII superior); PMC4786552, Figs 1-2. | ✓ |
| VI | Segment VI (right posterior, inferior) | Inferior segment of the right posterior section, posterolateral to the right-hepatic-vein plane and below the transverse right portal plane. VI pairs with VII in the Brisbane right posterior section. | Report VI and any boundary crossing, especially toward V, VII, IVC or the right hepatic vein. VI with VII forms the right posterior section; the code is localization input, not an operative instruction. | Segment VI carries no calibrated patient or procedure risk. Access, portal and hepatic venous anatomy, biliary relationships, lesion burden and functional reserve remain separate determinants. | Brisbane 2000 consensus, right posterior section; PMC4994882, Couinaud segments text (VI inferior, VII superior); PMC4786552, segmental anatomy and resection terminology. | ✓ |
| VII | Segment VII (right posterior, superior) | Superior segment of the right posterior section, posterolateral to the right-hepatic-vein plane and above the transverse right portal plane. VII pairs with VI in the Brisbane right posterior section. | Report VII with its relationship to the right hepatic vein, IVC, diaphragm and adjacent segments, including any boundary crossing. Do not infer a surgical approach or feasibility from the posterosuperior label alone. | VII has no intrinsic outcome score. Its posterosuperior location can affect access and planning, but patient-specific technical risk requires direct vascular, biliary, lesion and liver-reserve assessment. | Brisbane 2000 consensus, right posterior section; PMC4994882, Couinaud segments text (VII superior, VI inferior) and hepatic venous landmarks; PMC4786552, Fig 1. | ✓ |
| VIII | Segment VIII (right anterior, superior) | Superior segment of the right anterior section, generally between the middle- and right-hepatic-vein planes and above the transverse right portal plane. VIII pairs with V in the Brisbane right anterior section. | Report VIII and whether the lesion reaches IV, V, VII, the hepatic veins, IVC, hilum or dome. V with VIII forms the right anterior section, but this grouping does not itself choose resection or ablation. | VIII is a location code rather than a risk category. Central or posterosuperior relationships may influence access and vascular control, but no numeric prognosis follows from VIII itself. | Couinaud 1999, portal and hepatic-vein segmentation; Brisbane 2000 consensus, right anterior section; PMC4994882, Couinaud segments text (VIII superior, V inferior); PMC4786552, Figs 1-2. | ✓ |

### Citações por categoria
- **I**: Strasberg SM, Belghiti J, Clavien PA, Gadzijev E, Garden JO, Lau WY, Makuuchi M, Strong RW. The Brisbane 2000 Terminology of Liver Anatomy and Resections (2000) — https://doi.org/10.1016/S1365-182X(17)30755-4 · Couinaud 1999, PMID 10805544, portal plus suprahepatic segmentation; Anatomy of Hepatic Resectional Surgery, PMC4994882, Couinaud segments text and Fig 7; Brisbane context in PMC4786552, segment-1 naming rule.
- **II**: Strasberg SM, Belghiti J, Clavien PA, Gadzijev E, Garden JO, Lau WY, Makuuchi M, Strong RW. The Brisbane 2000 Terminology of Liver Anatomy and Resections (2000) — https://doi.org/10.1016/S1365-182X(17)30755-4 · IHPBA Brisbane 2000 consensus, DOI 10.1016/S1365-182X(17)30755-4, second- and third-order divisions; PMC4994882, Couinaud segments and Brisbane terminology; PMC4786552, Figs 1-2.
- **III**: Strasberg SM, Belghiti J, Clavien PA, Gadzijev E, Garden JO, Lau WY, Makuuchi M, Strong RW. The Brisbane 2000 Terminology of Liver Anatomy and Resections (2000) — https://doi.org/10.1016/S1365-182X(17)30755-4 · IHPBA Brisbane 2000 consensus, second-order left lateral section and third-order segment terminology; PMC4994882, Couinaud segments text explaining the original II versus III/IV sectors and Brisbane II/III versus IV sections.
- **IV**: Strasberg SM, Belghiti J, Clavien PA, Gadzijev E, Garden JO, Lau WY, Makuuchi M, Strong RW. The Brisbane 2000 Terminology of Liver Anatomy and Resections (2000) — https://doi.org/10.1016/S1365-182X(17)30755-4 · Brisbane 2000 consensus, left medial section and segment nomenclature; PMC4994882, Couinaud segments and Brisbane terminology, including variable IVa/IVb branching; PMC4786552, segment-oriented planning context.
- **IVa**: Strasberg SM, Belghiti J, Clavien PA, Gadzijev E, Garden JO, Lau WY, Makuuchi M, Strong RW. The Brisbane 2000 Terminology of Liver Anatomy and Resections (2000) — https://doi.org/10.1016/S1365-182X(17)30755-4 · PMC4994882, Couinaud segments text and Fig 5: segment IV may be divided into IVA superiorly and IVB inferiorly, with variable branching; Brisbane 2000 consensus for left medial-section terminology.
- **IVb**: Strasberg SM, Belghiti J, Clavien PA, Gadzijev E, Garden JO, Lau WY, Makuuchi M, Strong RW. The Brisbane 2000 Terminology of Liver Anatomy and Resections (2000) — https://doi.org/10.1016/S1365-182X(17)30755-4 · PMC4994882, Couinaud segments text and Fig 5 (IVB inferior to the left portal plane and variable subdivision); Brisbane 2000 consensus, left medial section.
- **V**: Strasberg SM, Belghiti J, Clavien PA, Gadzijev E, Garden JO, Lau WY, Makuuchi M, Strong RW. The Brisbane 2000 Terminology of Liver Anatomy and Resections (2000) — https://doi.org/10.1016/S1365-182X(17)30755-4 · Couinaud 1999, portal and hepatic-vein segmentation; Brisbane 2000 consensus, right anterior section; PMC4994882, Couinaud segments text (V inferior, VIII superior); PMC4786552, Figs 1-2.
- **VI**: Strasberg SM, Belghiti J, Clavien PA, Gadzijev E, Garden JO, Lau WY, Makuuchi M, Strong RW. The Brisbane 2000 Terminology of Liver Anatomy and Resections (2000) — https://doi.org/10.1016/S1365-182X(17)30755-4 · Brisbane 2000 consensus, right posterior section; PMC4994882, Couinaud segments text (VI inferior, VII superior); PMC4786552, segmental anatomy and resection terminology.
- **VII**: Strasberg SM, Belghiti J, Clavien PA, Gadzijev E, Garden JO, Lau WY, Makuuchi M, Strong RW. The Brisbane 2000 Terminology of Liver Anatomy and Resections (2000) — https://doi.org/10.1016/S1365-182X(17)30755-4 · Brisbane 2000 consensus, right posterior section; PMC4994882, Couinaud segments text (VII superior, VI inferior) and hepatic venous landmarks; PMC4786552, Fig 1.
- **VIII**: Strasberg SM, Belghiti J, Clavien PA, Gadzijev E, Garden JO, Lau WY, Makuuchi M, Strong RW. The Brisbane 2000 Terminology of Liver Anatomy and Resections (2000) — https://doi.org/10.1016/S1365-182X(17)30755-4 · Couinaud 1999, portal and hepatic-vein segmentation; Brisbane 2000 consensus, right anterior section; PMC4994882, Couinaud segments text (VIII superior, V inferior); PMC4786552, Figs 1-2.

## Histórico de versões

| Data | Evento | Detalhe | Situação |
| --- | --- | --- | --- |
| 2026-07-25 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2021-11-29 | revised | The Tokyo 2020 consensus added definitions for anatomic segmentectomy and subsegmentectomy while retaining the base segmental anatomy. | confirmed |
| 2000-05-01 | revised | The IHPBA Brisbane consensus standardized liver anatomy and resection terminology around the Couinaud segment map. | confirmed |
| 1957-01-01 | published | Couinaud published the classic segmental liver model in Le foie: etudes anatomiques et chirurgicales. | confirmed |


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