# AAST Liver — AAST Liver Organ Injury Scale

> Current grade I-V anatomic liver-trauma scale using the highest imaging, operative or pathologic finding across hematoma, laceration, parenchymal disruption, contained or free active bleeding and juxtahepatic venous injury. Hemodynamic status, associated injuries and resources remain separate management axes; grade alone neither mandates operation nor supplies an individual outcome probability.

**Situação:** vigente · **Órgão:** Fígado · **Órgão emissor:** American Association for the Surgery of Trauma · **Versão:** 2018 revision; WSES care boundary reviewed through 2020 · **Ano:** 2018

## Procedência e vigência
- Família: léxico
- Tipo de lógica: flat
- Modalidade: CT, Surgery, Pathology
- Fonte primária: Kozar RA, Crandall M, Shanmuganathan K, et al.. Organ injury scaling 2018 update: spleen, liver, and kidney (AAST) (2018) — https://doi.org/10.1097/TA.0000000000002058
- Última verificação: 2026-07-24
- Última checagem: 2026-07-24

## Lógica de decisão
Use the highest current 2018 anatomic criterion, expose measurements and bleeding location, and keep hemodynamics and treatment as explicit separate axes.

## Categorias

| Código | Rótulo | Critérios | Conduta | Risco | Localizador | Verificado |
| --- | --- | --- | --- | --- | --- | --- |
| I | Grade I | Subcapsular hematoma involving less than 10% of liver surface area and/or a capsular tear or parenchymal laceration less than 1 cm deep. Use the highest supported imaging, operative or pathologic finding. | In a hemodynamically stable patient without another indication for laparotomy, nonoperative management with appropriate monitoring is generally favored. Hemodynamic deterioration, associated injury and resource availability override the apparently low anatomic grade. | Grade I describes limited anatomic injury but does not guarantee benign clinical course or provide an individual bleeding, transfusion, complication or mortality probability. | Kozar et al. 2018, DOI 10.1097/TA.0000000000002058, revised liver OIS grade I row and highest-grade footnote; Coccolini et al. 2020, PMC7106618, nonoperative-management principles. | ✓ |
| II | Grade II | Subcapsular hematoma involving 10-50% of surface area, intraparenchymal hematoma less than 10 cm in diameter, and/or laceration 1-3 cm deep and 10 cm or less in length. Exact threshold measurements must be preserved. | Stable patients are usually considered for nonoperative management. Arterial blush or pseudoaneurysm can support angiography and angioembolization consideration in an equipped center, but grade II itself is not an embolization or operation order. | Grade II remains a lower anatomic tier, yet physiology and associated injuries are stronger immediate management determinants. No single embolization-success or nonoperative-failure percentage applies to every patient. | Kozar et al. 2018, current grade II hematoma and laceration thresholds; WSES 2020 sections on stable-patient nonoperative management and angioembolization. | ✓ |
| III | Grade III | Subcapsular hematoma greater than 50% or ruptured; intraparenchymal hematoma 10 cm or larger or ruptured; laceration greater than 3 cm deep; and/or contained hepatic vascular injury or active bleeding contained within liver parenchyma. | Nonoperative management can remain appropriate when hemodynamically stable and adequately monitored, often with interventional-radiology assessment for active arterial bleeding or contained vascular injury. Instability or another operative indication changes the pathway independently of the grade. | Grade III combines several different morphologic branches and therefore is not one calibrated risk state. Contained bleeding, a deep laceration and a large hematoma may have different trajectories despite sharing the numeral. | Kozar et al. 2018, current grade III row including contained vascular injury and active bleeding; WSES 2020, nonoperative and angiography guidance. | ✓ |
| IV | Grade IV | Parenchymal disruption involving 25-75% of one hepatic lobe or one to three Couinaud segments within one lobe, and/or active bleeding extending beyond the liver parenchyma into the peritoneum. | A stable grade IV patient may still undergo nonoperative management in a high-capability setting with close surveillance and angioembolization when indicated. Hemodynamic instability or nonresponse to resuscitation drives urgent operative hemorrhage control, not the grade numeral by itself. | Grade IV signals substantial anatomic injury or free active bleeding, but cannot by itself quantify nonoperative failure, mortality or transfusion need. Physiology, coagulopathy, associated injuries and resources dominate individual risk. | Kozar et al. 2018, grade IV parenchymal-disruption and free-active-bleeding criteria; WSES 2020, stable high-grade nonoperative and unstable operative pathways. | ✓ |
| V | Grade V | Parenchymal disruption involving more than 75% of one hepatic lobe or more than three Couinaud segments within one lobe, and/or juxtahepatic venous injury involving the retrohepatic inferior vena cava or central major hepatic veins. | Urgently integrate physiology, hemorrhage control, vascular anatomy, associated injuries and specialist resources. Selected stable patients may remain in a nonoperative or interventional pathway, whereas instability requires operative damage control; grade V does not prescribe a specific repair. | This is the highest current liver OIS tier, but its branches are heterogeneous and do not yield an individual survival or treatment-success percentage. Juxtahepatic venous injury and extensive parenchymal disruption require explicit description beyond the numeral. | Kozar et al. 2018, current grade V row; WSES 2020 sections on severe liver injury, hemodynamic classification and operative or nonoperative resource requirements. | ✓ |

### Citações por categoria
- **I**: Kozar RA, Crandall M, Shanmuganathan K, et al.. Organ injury scaling 2018 update: spleen, liver, and kidney (AAST) (2018) — https://doi.org/10.1097/TA.0000000000002058 · Kozar et al. 2018, DOI 10.1097/TA.0000000000002058, revised liver OIS grade I row and highest-grade footnote; Coccolini et al. 2020, PMC7106618, nonoperative-management principles.
- **II**: Kozar RA, Crandall M, Shanmuganathan K, et al.. Organ injury scaling 2018 update: spleen, liver, and kidney (AAST) (2018) — https://doi.org/10.1097/TA.0000000000002058 · Kozar et al. 2018, current grade II hematoma and laceration thresholds; WSES 2020 sections on stable-patient nonoperative management and angioembolization.
- **III**: Kozar RA, Crandall M, Shanmuganathan K, et al.. Organ injury scaling 2018 update: spleen, liver, and kidney (AAST) (2018) — https://doi.org/10.1097/TA.0000000000002058 · Kozar et al. 2018, current grade III row including contained vascular injury and active bleeding; WSES 2020, nonoperative and angiography guidance.
- **IV**: Kozar RA, Crandall M, Shanmuganathan K, et al.. Organ injury scaling 2018 update: spleen, liver, and kidney (AAST) (2018) — https://doi.org/10.1097/TA.0000000000002058 · Kozar et al. 2018, grade IV parenchymal-disruption and free-active-bleeding criteria; WSES 2020, stable high-grade nonoperative and unstable operative pathways.
- **V**: Kozar RA, Crandall M, Shanmuganathan K, et al.. Organ injury scaling 2018 update: spleen, liver, and kidney (AAST) (2018) — https://doi.org/10.1097/TA.0000000000002058 · Kozar et al. 2018, current grade V row; WSES 2020 sections on severe liver injury, hemodynamic classification and operative or nonoperative resource requirements.

## Histórico de versões

| Data | Evento | Detalhe | Situação |
| --- | --- | --- | --- |
| 2020-04-30 | revised | WSES published current management context integrating AAST anatomy with hemodynamic status and resource capability; this did not alter the AAST grade definitions. | confirmed |
| 2018-12-01 | revised | AAST published the current liver OIS revision with explicit CT vascular-injury, active-bleeding and parenchymal-disruption criteria. | confirmed |


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> Conteúdo de referência reescrito. Confira a publicação primária vigente. Não é dispositivo médico nem substitui o julgamento clínico. O radiologista responsável pelo laudo permanece o autor e o responsável.

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