# St James — St James University Hospital classification of perianal fistula

> Grades perianal fistulas on MRI by anatomy and complications.

**Situação:** vigente · **Órgão:** Cólon · **Órgão emissor:** Radiology consensus · **Versão:** 2000 · **Ano:** 2000

## Procedência e vigência
- Família: léxico
- Tipo de lógica: flat
- Modalidade: MRI
- Fonte primária: Morris J, Spencer JA, Ambrose NS. MR imaging classification of perianal fistulas (St James University Hospital) (2000) — https://pmc.ncbi.nlm.nih.gov/articles/PMC4394844/
- Última verificação: 2026-06-26
- Última checagem: 2026-06-26

## Categorias

| Código | Rótulo | Critérios | Conduta | Risco | Localizador | Verificado |
| --- | --- | --- | --- | --- | --- | --- |
| 1 | Grade 1 | Simple linear intersphincteric fistula (single tract penetrating the internal sphincter to run between internal and external sphincters and exit the perineum, with no secondary extension or abscess). | Counts as a 'simple'/low fistula: generally amenable to laying-open (fistulotomy/fistulectomy) with low risk of incontinence, since no external-sphincter muscle is divided. | Favorable: grades 1-2 were associated with a satisfactory outcome, versus grades 3-5 (unsatisfactory, e.g. need for further surgery; P<0.001) in the cited series. | Criteria/management/outcome: PMC4394844 ('MRI of Perianal Fistulas'), section 'Classification of Perianal Fistulae' (Grade 1 = 'a simple intersphincteric fistula' penetrating between the sphincters) and the outcome statement 'grades 1 and 2 were associated with satisfactory outcome whereas grades 3-5 were associated with unsatisfactory outcome ... (P<0.001)'; simple/low-fistula fistulotomy principle from the same article. | ✓ |
| 2 | Grade 2 | Intersphincteric fistula with an intersphincteric secondary tract or abscess. | Still intersphincteric (no trans-sphincteric muscle involvement) but with a secondary tract/abscess that must be drained/laid open in addition to treating the primary tract; broadly grouped with the lower-risk fistulas for sphincter-sparing intent. | Favorable: grades 1-2 were associated with a satisfactory outcome (vs unsatisfactory for grades 3-5; P<0.001) in the cited series. | Criteria: PMC4394844, 'Classification of Perianal Fistulae', Grade 2 = 'an intersphincteric fistula with a secondary tract or abscess'. Outcome/risk: same article, 'grades 1 and 2 were associated with satisfactory outcome whereas grades 3-5 ... unsatisfactory ... (P<0.001)'. | ✓ |
| 3 | Grade 3 | Simple (uncomplicated) transsphincteric fistula (tract crosses both the internal and external sphincters into the ischioanal fossa without secondary extension or abscess). | Trans-sphincteric tracts cross the external sphincter, so simple laying-open risks incontinence (>50% with the lay-open technique for complex disease); sphincter-preserving options (e.g. seton, advancement flap) are favored, the more so with the higher grades. | Less favorable: grades 3-5 were associated with an unsatisfactory outcome (e.g. need for further surgery), in contrast to satisfactory outcomes for grades 1-2 (P<0.001) in the cited series. | Criteria: PMC4394844, 'Classification of Perianal Fistulae', Grade 3 = 'simple transphincteric fistulae'. Management/outcome: same article — incontinence '>50%' with laying-open of complex fistulas, and 'grades 3-5 were associated with unsatisfactory outcome ... (P<0.001)'. | ✓ |
| 4 | Grade 4 | Transsphincteric fistula with an associated secondary tract or abscess (a more complicated transsphincteric process), typically extending into the ischioanal/ischiorectal fossa. | Complex fistula: laying-open is avoided (incontinence in >50% of cases); managed with sphincter-preserving and/or staged techniques (non-cutting seton, mucosal advancement flap) plus drainage of the secondary tract/abscess. | Unfavorable: grade 4 falls in the grades 3-5 band associated with an unsatisfactory outcome / need for further surgery (vs satisfactory for grades 1-2; P<0.001) in the cited series. | Criteria: PMC4394844, Grade 4 = 'a more complicated transphincteric process with a secondary tract or abscess'; ischioanal/ischiorectal-fossa site corroborated by WebSearch summaries of St James / Morris 2000 on pmc.ncbi.nlm.nih.gov. Management/outcome: same article — complex fistulas need sphincter-preserving/staged surgery (lay-open incontinence '>50%') and 'grades 3-5 ... unsatisfactory outcome ... (P<0.001)'. | ✓ |
| 5 | Grade 5 | Supralevator and/or translevator disease (a complicated fistula/abscess with a supralevator or translevator component, extending above the level of the levator ani). | Most complex group: requires sphincter-preserving and often staged/specialist surgery (seton, advancement flap, treatment of the supra/translevator component) with imaging-guided planning; simple laying-open is contraindicated given the high incontinence risk. | Most unfavorable: grade 5 lies in the grades 3-5 band associated with an unsatisfactory outcome / need for further surgery (vs satisfactory for grades 1-2; P<0.001) in the cited series. | Criteria: PMC4394844, Grade 5 = 'a complicated abscess with a supra or translevator component'. Management/outcome: same article — complex/high disease needs sphincter-preserving/staged surgery (lay-open incontinence '>50%') and 'grades 3-5 were associated with unsatisfactory outcome ... (P<0.001)'. | ✓ |

### Citações por categoria
- **1**: Morris J, Spencer JA, Ambrose NS. MR imaging classification of perianal fistulas (St James University Hospital) (2000) — https://pmc.ncbi.nlm.nih.gov/articles/PMC4394844/ · Criteria/management/outcome: PMC4394844 ('MRI of Perianal Fistulas'), section 'Classification of Perianal Fistulae' (Grade 1 = 'a simple intersphincteric fistula' penetrating between the sphincters) and the outcome statement 'grades 1 and 2 were associated with satisfactory outcome whereas grades 3-5 were associated with unsatisfactory outcome ... (P<0.001)'; simple/low-fistula fistulotomy principle from the same article.
- **2**: Morris J, Spencer JA, Ambrose NS. MR imaging classification of perianal fistulas (St James University Hospital) (2000) — https://pmc.ncbi.nlm.nih.gov/articles/PMC4394844/ · Criteria: PMC4394844, 'Classification of Perianal Fistulae', Grade 2 = 'an intersphincteric fistula with a secondary tract or abscess'. Outcome/risk: same article, 'grades 1 and 2 were associated with satisfactory outcome whereas grades 3-5 ... unsatisfactory ... (P<0.001)'.
- **3**: Morris J, Spencer JA, Ambrose NS. MR imaging classification of perianal fistulas (St James University Hospital) (2000) — https://pmc.ncbi.nlm.nih.gov/articles/PMC4394844/ · Criteria: PMC4394844, 'Classification of Perianal Fistulae', Grade 3 = 'simple transphincteric fistulae'. Management/outcome: same article — incontinence '>50%' with laying-open of complex fistulas, and 'grades 3-5 were associated with unsatisfactory outcome ... (P<0.001)'.
- **4**: Morris J, Spencer JA, Ambrose NS. MR imaging classification of perianal fistulas (St James University Hospital) (2000) — https://pmc.ncbi.nlm.nih.gov/articles/PMC4394844/ · Criteria: PMC4394844, Grade 4 = 'a more complicated transphincteric process with a secondary tract or abscess'; ischioanal/ischiorectal-fossa site corroborated by WebSearch summaries of St James / Morris 2000 on pmc.ncbi.nlm.nih.gov. Management/outcome: same article — complex fistulas need sphincter-preserving/staged surgery (lay-open incontinence '>50%') and 'grades 3-5 ... unsatisfactory outcome ... (P<0.001)'.
- **5**: Morris J, Spencer JA, Ambrose NS. MR imaging classification of perianal fistulas (St James University Hospital) (2000) — https://pmc.ncbi.nlm.nih.gov/articles/PMC4394844/ · Criteria: PMC4394844, Grade 5 = 'a complicated abscess with a supra or translevator component'. Management/outcome: same article — complex/high disease needs sphincter-preserving/staged surgery (lay-open incontinence '>50%') and 'grades 3-5 were associated with unsatisfactory outcome ... (P<0.001)'.


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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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