Anorectal Stricture

Abnormal narrowing of the anal canal.

Anorectal strictures can be classified based on severity and location

Classification of Anorectal Stricture

Adapted from Liberman H, Thorson AG: How I do it. Anal stenosis. Am J Surg 179:325-329, 2000. In Cameron JL, Cameron AM: Current surgical therapy, ed 12, Philadelphia, 2017, Elsevier.

Severity	Location
Mild: Stricture present,but allows passage of well-lubricated finger or medium Hill-Ferguson retractor	Low: At least 0.5 cm distal to the dentate line
Moderate: Passage of well-lubricated finger or medium Hill-Ferguson retractor only with forceful dilation	Middle: 0.5 cm on either side of the dentate line
Severe: No passage of well-lubricated finger or medium Hill-Ferguson retractor	High: At least 0.5 cm proximal to the dentate line

Synonyms

Anal stenosis
Küss disease

Epidemiology & Demographics

Incidence

Hemorrhoid surgery is considered the most common cause of anorectal stricture overall.
5% to 10% of postradical hemorrhoidectomy surgeries

Risk Factors

Previous anorectal surgery, inflammatory bowel disease, prior radiation, hemorrhoids

Physical Findings & Clinical Presentation

•History:
- 1.Most common symptom is pain with defecation
- 2.Patients also may report bleeding, narrowing of stools, constipation, fecal incontinence, tenesmus, and urgency
- 3.Important to ask about past anorectal surgeries, Crohn disease, or perianal trauma
•Physical examination:
- 1.Visual inspection of the anus may demonstrate skin tags or chronic fissures
- 2.Digital rectal examination will demonstrate a narrowed anal canal through which it is difficult to pass a lubricated finger
- 3.In severe cases, examination under anesthesia may be required

Etiology

Can be divided into three groups based on etiology:
- •Congenital: Pediatric condition secondary to abnormalities in embryologic development
- •Congenital malformation: Anal atresia, imperforate anus
- •Primary: Typically in elderly due to fibrous involution of perianal tissues
- •Secondary: Development secondary to other cause. Most common is iatrogenic, following hemorrhoid or other anorectal surgery
  - 1.Fibrosis of anoderm or distal rectal mucosa due to a surgical procedure:
    - a.Hemorrhoidectomy
    - b.Low anterior resection
    - c.Ileal pouch-anal anastomosis
    - d.Anopexy
    - e.Excision of perianal skin lesion
  - 2.Anal canal muscle hypertrophy
  - 3.Anal canal muscle spasm (anismus) secondary to anal fissure
  - 4.Neoplasia:
    - a.Bowen disease
    - b.Paget disease
    - c.Anal squamous cell carcinoma
    - d.Rectal adenocarcinoma
    - e.Condyloma acuminata
  - 5.Inflammation:
    - a.Anal fissure
    - b.Crohn disease
    - c.Tuberculosis
    - d.Actinomycosis
    - e.Lymphogranuloma venereum
    - f.Chronic suppuration
  - 6.Trauma:
    - a.Radiation therapy
    - b.Perineal burns
    - c.Hot water enemas
    - d.Ibuprofen suppositories
    - e.Chronic laxative abuse
  - 7.Sexually transmitted disease
  - 8.Here is the summary of the common causes of anorectal strictures

Causes of Anorectal Stricture

From Cameron JL, Cameron AM: Current surgical therapy, ed 12, Philadelphia, 2017, Elsevier.

Surgical Procedures

Hemorrhoidectomy
Low anterior resection
Ileal pouch-anal anastomosis
Anopexy
Excision of perianal skin lesions

Neoplastic

Bowen disease
Paget disease
Anal squamous cell carcinoma
Rectal adenocarcinoma
Condyloma acuminata

Inflammatory

Anal fistula
Crohn disease
Tuberculosis
Actinomycosis
Lymphogranuloma venereum

Trauma

Radiation therapy
Perineal burns
Hot water enemas
Ibuprofen suppositories
Chronic laxative abuse

Differential Diagnosis

•Anorectal stricture/stenosis
•Neoplasm
•Inflammatory bowel disease
•Trauma

Workup

•Anorectal stricture is a clinical diagnosis, but other possible causes such as neoplasm, inflammatory disease need to be ruled out.
•Suspicious lesions should be biopsied.
•Hydration, fiber supplementation, and stool softeners should be started in all patients regardless of ultimate etiology.

Treatment

Nonpharmacologic Therapy

•Manual dilation using digital method or commercial dilators may be started in the clinic or operating room and continued on an outpatient basis
•Resection of neoplasm
•Stricturoplasty
•Anoplasty

Chronic Treatment

For mild disease, stool softeners, fiber supplementation, and dietary modification are all that is necessary.

Complementary & Alternative Medicine

None

Disposition

Mild strictures can be treated on an outpatient basis in clinic; moderate to severe strictures require colorectal surgical evaluation.

Referral

Referral is indicated when there is concern for neoplasm, patients who fail conservative medical management, or if the provider is unable to pass a lubricated finger into the rectum.

Anorectal Stricture