# AAST Kidney OIS — AAST Kidney Organ Injury Scale

> Current per-kidney grade I-V traumatic renal injury scale using the highest imaging, operative or pathologic finding. The 2025 revision adds explicit laceration and hematoma measurements, separates contained vascular injury from active bleeding, regrades collecting-system injury, defines pararenal hematoma and multifragmented kidney, and does not prescribe treatment from grade alone.

**Situação:** vigente · **Órgão:** Rim · **Órgão emissor:** American Association for the Surgery of Trauma · **Versão:** 2025 revision · **Ano:** 2025

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

## Procedência e vigência
- Família: léxico
- Tipo de lógica: flat
- Modalidade: CT
- Fonte primária: Keihani S, Tominaga GT, Matta R, et al.. Kidney organ injury scaling: 2025 update (2025) — https://pubmed.ncbi.nlm.nih.gov/39836096/
- Última verificação: 2026-07-24
- Última checagem: 2026-08-12

## Lógica de decisão
Apply the 2025 per-kidney highest-finding algorithm, preserve source provenance and version, and keep anatomic grade separate from hemodynamics and treatment.

## Categorias

| Código | Rótulo | Critérios | Conduta | Risco | Localizador | Verificado |
| --- | --- | --- | --- | --- | --- | --- |
| I | Grade I | 2025 grade I is a subcapsular hematoma under 3.5 cm without active bleeding, or a renal parenchymal contusion without laceration. Apply the highest qualifying finding per kidney; a laceration, larger hematoma measurement, active bleeding or another higher-grade feature overrides grade I. | In a hemodynamically stable or stabilized patient, renal-preserving nonoperative care with clinical and laboratory monitoring is generally appropriate for isolated low-grade anatomy. The code does not replace trauma assessment: instability, ongoing blood loss, associated injury or clinical deterioration requires escalation independent of the grade. | Grade I is the least anatomically advanced 2025 category, but it provides no universal probability of delayed bleeding, renal-function loss or length of stay. Mechanism, anticoagulation, solitary kidney, associated trauma and physiology remain relevant, and a low renal grade does not exclude a dangerous injury elsewhere. | Keihani et al. 2025, PMID 39836096, current AAST update; Jeon 2025, DOI 10.64961/kjir.2025.00052, Table 1 grade I and measurement footnotes; WSES-AAST 2019 and current EAU guidance for stable-patient management boundary. | ✓ |
| II | Grade II | 2025 grade II includes renal parenchymal laceration length under 2.5 cm or hematoma rim distance under 3.5 cm without active bleeding. Laceration length is the longest length on one axial image; HRD is measured perpendicular from renal parenchyma to the bulk hematoma border within the kidney's superior-inferior extent. | Stable or stabilized patients are usually managed nonoperatively with renal-preserving observation and reassessment tailored to the whole trauma. Do not order embolization or surgery from grade II alone. Escalate when physiology, transfusion need, expanding hemorrhage, new vascular findings, associated injury or another clinical complication supplies an independent indication. | Grade II remains low-grade anatomy but is not risk-free and is not a validated bedside probability. Measurement quality near 2.5 cm or 3.5 cm can change the code, and outcomes depend on physiology, mechanism and comorbidity. Preserve uncertainty rather than presenting a threshold-adjacent measurement as exact. | Keihani et al. 2025 and Jeon 2025 Table 1, grade II thresholds and axial measurement definitions; AAST official OIS revision page confirms 2025 as current; WSES-AAST and EAU for nonoperative stable-patient context. | ✓ |
| III | Grade III | 2025 grade III is assigned for any of: parenchymal laceration length at least 2.5 cm; HRD at least 3.5 cm without active bleeding; partial kidney infarction; a contained vascular injury without active bleeding such as pseudoaneurysm, arteriovenous fistula, dissection, thrombosis, intimal flap or mural hematoma; or laceration into the collecting system and/or urinary extravasation. | Hemodynamically stable or stabilized grade-III anatomy can often receive nonoperative renal-preserving care. Evaluate a contained vascular lesion, hematoma trajectory and clinical bleeding for selective angiography or embolization, and initially observe many parenchymal urinary leaks while assessing for persistent leak, infection, obstruction or suspected proximal avulsion. Management follows anatomy and physiology, not the Roman numeral alone. | This category is heterogeneous: a length-threshold laceration, contained vascular lesion, partial infarct and urinary leak do not share one complication probability. Active bleeding would move the anatomy to grade IV, while a collecting-system leak is now grade III rather than IV. Report the qualifying feature because it carries more actionable risk information than the grade token. | Keihani et al. 2025; Jeon 2025 Table 1 grade III and contained-vascular definitions; Kozar et al. 2018 for predecessor comparison; AUA 2020, WSES-AAST 2019, EAST 2023 and EAU for bleeding and urinary-leak management context, interpreted by anatomy because those guidelines predate the 2025 remapping. | ✓ |
| IV | Grade IV | 2025 grade IV is assigned for active bleeding from the kidney; pararenal extension of hematoma; complete or near-complete kidney infarction without active bleeding; a multifragmented kidney without active bleeding; or complete or near-complete ureteropelvic-junction disruption. Pararenal extension and MFK require the scale's explicit definitions, not subjective use of large or shattered. | This grade requires urgent multidisciplinary trauma, urology and interventional-radiology assessment, but it still does not mandate one treatment. Stable or stabilized patients may be candidates for nonoperative renal preservation, selective embolization for active bleeding, or drainage and reconstruction for specific urinary injury; refractory hemodynamic instability or failed hemorrhage control can require immediate surgery. | Grade IV identifies major anatomy and a higher likelihood of intervention than low-grade injury, but it is not an individual mortality or nephrectomy calculator. Active bleeding, avascular kidney, pararenal spread, MFK without bleeding and UPJ disruption have different mechanisms and consequences. State the qualifying feature, hemodynamics, transfusion and associated injuries. | Keihani et al. 2025; Jeon 2025 Table 1 grade IV and footnote definitions of active bleeding, pararenal hematoma and MFK; AUA, WSES-AAST, EAST and EAU management guidance with explicit warning that legacy grade-number recommendations require anatomic remapping after 2025. | ✓ |
| V | Grade V | 2025 grade V is assigned for main renal artery or vein laceration or transection with active bleeding, complete or near-complete kidney infarction with active bleeding, or a multifragmented kidney with active bleeding. MFK means at least three injured parenchymal segments separated by fluid or blood; active bleeding distinguishes the grade-V MFK pattern from grade IV. | Provide immediate hemorrhage-control and renal-salvage assessment based on hemodynamic response and associated trauma. Unstable patients may require operative control including nephrectomy when repair is not feasible; selected stabilized patients at experienced centers can undergo endovascular or renal-preserving strategies. Grade V must never be converted automatically into nephrectomy, futility or a treatment limitation. | Grade V is the most anatomically advanced current category and signals substantial hemorrhagic and renal-loss concern, yet no single outcome probability applies to all three qualifying patterns. Survival and salvage depend on physiology, ischemia, associated injury, time to control and expertise. Do not import grade-V rates from a 2018 cohort without reclassifying its anatomy. | Keihani et al. 2025; Jeon 2025 Table 1 grade V and MFK/active-bleeding definitions; WSES-AAST, EAST and current EAU guidance for physiology-led hemorrhage control and selected renal preservation. | ✓ |

### Citações por categoria
- **I**: Keihani S, Tominaga GT, Matta R, et al.. Kidney organ injury scaling: 2025 update (2025) — https://pubmed.ncbi.nlm.nih.gov/39836096/ · Keihani et al. 2025, PMID 39836096, current AAST update; Jeon 2025, DOI 10.64961/kjir.2025.00052, Table 1 grade I and measurement footnotes; WSES-AAST 2019 and current EAU guidance for stable-patient management boundary.
- **II**: Keihani S, Tominaga GT, Matta R, et al.. Kidney organ injury scaling: 2025 update (2025) — https://pubmed.ncbi.nlm.nih.gov/39836096/ · Keihani et al. 2025 and Jeon 2025 Table 1, grade II thresholds and axial measurement definitions; AAST official OIS revision page confirms 2025 as current; WSES-AAST and EAU for nonoperative stable-patient context.
- **III**: Keihani S, Tominaga GT, Matta R, et al.. Kidney organ injury scaling: 2025 update (2025) — https://pubmed.ncbi.nlm.nih.gov/39836096/ · Keihani et al. 2025; Jeon 2025 Table 1 grade III and contained-vascular definitions; Kozar et al. 2018 for predecessor comparison; AUA 2020, WSES-AAST 2019, EAST 2023 and EAU for bleeding and urinary-leak management context, interpreted by anatomy because those guidelines predate the 2025 remapping.
- **IV**: Keihani S, Tominaga GT, Matta R, et al.. Kidney organ injury scaling: 2025 update (2025) — https://pubmed.ncbi.nlm.nih.gov/39836096/ · Keihani et al. 2025; Jeon 2025 Table 1 grade IV and footnote definitions of active bleeding, pararenal hematoma and MFK; AUA, WSES-AAST, EAST and EAU management guidance with explicit warning that legacy grade-number recommendations require anatomic remapping after 2025.
- **V**: Keihani S, Tominaga GT, Matta R, et al.. Kidney organ injury scaling: 2025 update (2025) — https://pubmed.ncbi.nlm.nih.gov/39836096/ · Keihani et al. 2025; Jeon 2025 Table 1 grade V and MFK/active-bleeding definitions; WSES-AAST, EAST and current EAU guidance for physiology-led hemorrhage control and selected renal preservation.

## Histórico de versões

| Data | Evento | Detalhe | Situação |
| --- | --- | --- | --- |
| 2026-08-12 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-08-11 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-08-10 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-08-09 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-08-08 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-08-07 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-08-06 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-08-05 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-08-04 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-08-03 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-08-02 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-08-01 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-07-31 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-07-30 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-07-29 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-07-28 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-07-27 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-07-26 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2026-07-25 | revised | Monitored source changed (content_hash). Detected automatically; awaiting reviewer confirmation. | needs_review |
| 2025-01-20 | revised | AAST published the current multidisciplinary kidney OIS revision with 2.5 cm laceration and 3.5 cm hematoma thresholds, regraded urinary extravasation, explicit bleeding and MFK rules, separate per-kidney grading and no multiple-injury upgrade. | confirmed |
| 2018-12-01 | revised | The 2018 AAST revision incorporated CT vascular injury, active bleeding and collecting-system findings; it is retained as the immediate predecessor, not the current renal scale. | confirmed |


---
> 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.

Página HTML: https://radcommons.laudos.ai/systems/aast-kidney · JSON da API: https://radcommons.laudos.ai/api/v1/systems/aast-kidney · Índice para agentes: https://radcommons.laudos.ai/llms.txt