Anal Fissure

An anal fissure is a painful superficial tear of the epithelial lining (anoderm) of the anal canal. Anal fissures most often occur secondary to local trauma or irritation from constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation, diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea, anal intercourse, or perineal lacerations during childbirth. Treatment is generally conservative, including stool softeners, bulking agents, sitz baths, and/or topical vasodilators.

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Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

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Definition and Epidemiology

Definition

  • Superficial tear of the epithelial lining (anoderm) of the anal canal 
  • Distal to the dentate line
  • Acute fissures involve the epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium.
  • Chronic fissures involve the full thickness of the anal mucosa.

Epidemiology

  • Most common in infants and middle-aged adults
  • Exact incidence unknown
  • Males and females equally affected

Etiology and Pathophysiology

Etiology

  • Acute fissure
    • Forceful dilation of the anal canal (local trauma) due to:
      • Large, hard stools secondary to constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation
      • Irritating, diarrheal stools
      • Anal intercourse
    • Other causes:
      • Habitual use of cathartics
      • Childbirth with 3rd- or 4th-degree perineal lacerations
  • Chronic fissure (due to underlying disease)
    • Previous anal surgery (possible stenosis of the anal canal)
    • Crohn’s disease
    • Infections
      • Tuberculosis Tuberculosis Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis complex bacteria. The bacteria usually attack the lungs but can also damage other parts of the body. Approximately 30% of people around the world are infected with this pathogen, with the majority harboring a latent infection. Tuberculosis spreads through the air when a person with active pulmonary infection coughs or sneezes. Tuberculosis
      • HIV
      • Chlamydia Chlamydia Chlamydiae are obligate intracellular gram-negative bacteria. They lack a peptidoglycan layer and are best visualized using Giemsa stain. The family of Chlamydiaceae comprises 3 pathogens that can infect humans: Chlamydia trachomatis, Chlamydia psittaci, and Chlamydia pneumoniae. Chlamydia
      • Syphilis Syphilis Syphilis is a bacterial infection caused by the spirochete Treponema pallidum pallidum (T. p. pallidum), which is usually spread through sexual contact. Syphilis has 4 clinical stages: primary, secondary, latent, and tertiary. Syphilis
    • Leukemia
    • Squamous cell anal carcinoma

Pathophysiology

  • Location: 90% posterior midline, 10% anterior midline 
    • Most posterior midline fissures occur due to:
      • Shearing forces during defecation
      • Decreased elasticity of the anal epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium
      • Increased density of longitudinal muscle extensions
    • Most anterior midline fissures occur from vaginal delivery
    • If the anal fissure is not midline, consider possible causes such as Crohn’s disease, infections, or anal cancer Anal cancer Anal cancer accounts for 2.7% of all gastrointestinal tract cancers. Squamous cell carcinoma is the most common type of anal cancer. The patient can present with rectal bleeding (most common), change in bowel habits, perianal pruritic mass, or perianal painful ulceration. Anal Cancer.
  • Repetitive injury often occurs due to:
    • Local trauma
    • Anal hypertonicity
      • Tightening of the anal canal secondary to pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain leads to further tearing.
    • Sphincter spasm
      • Prevents edges from healing and leads to further tearing
    • Vascular insufficiency due to:
      • Increased sphincter tone 
      • Decreased perfusion from large anal canal circumference

Clinical Presentation

  • Acute fissure
    • Symptoms: < 8 weeks
    • History:
      • Severe onset of anal pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain with defecation; often lasts for hours afterward
      • Constipation
      • Hematochezia (bright-red blood in stools)
    • Physical exam findings:
      • Sphincter spasm on digital rectal examination (DRE) due to the pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain
      • Often appears as a superficial laceration in anal mucosa
  • Chronic fissure
    • Symptoms: lasting > 8 weeks
    • Physical exam findings:
      • Tear in anal mucosa with possible visible fibers of anal sphincter
      • Sentinel skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin tags (external skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Structure and Function of the Skin tags)
      • Hypertrophied anal papillae

Diagnosis and Management

Diagnosis

  • History is often classic and the basis of diagnosis.
  • Confirmed on physical examination by:
    • Direct visualization
    • Reproducible anal pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain with gentle palpation
  • If fissure is not midline or history is more complicated, then additional testing may be warranted:
    • Anoscopy
    • Biopsy
    • HIV testing
    • Stool cultures

Management

  • Medical management
    • Goals: 
      • Eliminate constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation
      • Decrease anal spams.
      • Prevent further anal epithelial tears. 
      • Promote healing.
    • Treatment may include:
      • Stool softeners, bulking agents, sitz baths
      • Topical nitroglycerin or nifedipine: increases local blood flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure (vasodilates), promoting healing and relieving sphincter spasm
      • Topical lidocaine
      • Botulinum toxin injections
        • Inhibit the release of acetylcholine (ACh)
        • Reduce sphincter spasm
        • Long lasting (up to 3 months)
  • Surgical management
    • Reserved for fissures refractory to medical management or chronic fissures 
    • Surgical options:
      • Lateral internal anal sphincterotomy 
        • Most effective
        • Current procedure of choice
        • Relieves sphincter spasm → increases blood flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure and promotes healing 
        • Can be done with or without fissurectomy
      • Anal advancement flap (anoplasty)
      • Sphincter dilation (no longer commonly used secondary to high complication rates)

Mnemonic

The “Ds” of anal fissures: 

  • Distal to the Dental line
  • bleeDing During Defecation; 
  • Dull puDenDal pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain
  • Diet low in fiber ( constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation)

Differential Diagnosis

  • Anal carcinoma: neoplastic disease in which cancer cells form and grow in the anus. Symptoms include bleeding from the anus, anal pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain, anal mass, or itching. Risk factors include older age, infections such as human papillomavirus Human papillomavirus Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomaviridae: HPV ( HPV HPV Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomaviridae: HPV), multiple sexual partners, and anal sex. Anal carcinoma is diagnosed by biopsy. Treatment can include surgery, radiation, or chemotherapy. In a chronic or atypical anal fissure, anal carcinoma needs to be ruled out.
  • Anal fistula Anal fistula Anal fistulas are abnormal communications between the anorectal lumen and another body structure, often to the skin. Anal fistulas often occur due to extension of anal abscesses but are also associated with specific diseases such as Crohn's disease. Anal Fistula or abscess: an abnormal connection between the epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium of the anal canal and another body structure. Anal fistulas often occur due to extension of anal abscesses. Symptoms include anal pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain or abnormal discharge/drainage. Management is primarily surgical, with a fistulotomy. Anal abscesses produce a tender bulge/mass in the anorectal region. In anal fistulas, there is the presence of a palpable fistulous tract.
  • Hemorrhoids: enlargement of anal cushions (submucosal vessels) at the distal rectum Rectum The rectum and anal canal are the most terminal parts of the lower GI tract/large intestine that form a functional unit and control defecation. Fecal continence is maintained by several important anatomic structures including rectal folds, anal valves, the sling-like puborectalis muscle, and internal and external anal sphincters. Rectum and Anal Canal. Depending on the location of the veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins, hemorrhoids Hemorrhoids Hemorrhoids are normal vascular cushions in the anal canal composed of dilated vascular tissue, smooth muscle, and connective tissue. They do not cause issues unless they are enlarged, inflamed, thrombosed, or prolapsed. Patients often present with rectal bleeding of bright red blood, or they may have pain, perianal pruritus, or a palpable mass. Hemorrhoids can be internal or external. External hemorrhoids Hemorrhoids Hemorrhoids are normal vascular cushions in the anal canal composed of dilated vascular tissue, smooth muscle, and connective tissue. They do not cause issues unless they are enlarged, inflamed, thrombosed, or prolapsed. Patients often present with rectal bleeding of bright red blood, or they may have pain, perianal pruritus, or a palpable mass. Hemorrhoids are painful, whereas internal hemorrhoids Hemorrhoids Hemorrhoids are normal vascular cushions in the anal canal composed of dilated vascular tissue, smooth muscle, and connective tissue. They do not cause issues unless they are enlarged, inflamed, thrombosed, or prolapsed. Patients often present with rectal bleeding of bright red blood, or they may have pain, perianal pruritus, or a palpable mass. Hemorrhoids are painless; both can bleed and appear as a soft rectal mass on exam. Commonly caused by constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation, and diagnosed on exam. Treatment includes stool softeners, topical hydrocortisone, and sitz baths. Additional treatment options are rubber band ligation or surgical removal.  
  • Perianal ulcerations: erosions in the perianal mucosa. Occur secondary to inflammatory bowel disease, most notably Crohn’s disease, infections, and cancer. Symptoms include pain Pain Pain has accompanied humans since they first existed, first lamented as the curse of existence and later understood as an adaptive mechanism that ensures survival. Pain is the most common symptomatic complaint and the main reason why people seek medical care. Physiology of Pain, bleeding, and erosions in the lining of the mucosa. Treatment is aimed at the causative disease. Perianal ulcerations are differentiated from anal fissures on physical exam by deeper erosions in mucosa and evidence of other causative diseases.

References

  1. Poritz, Lisa A. (2020). Anal Fissure Treatment & Management. Medscape. Retrieved Oct 2, 2020, from https://emedicine.medscape.com/article/196297-treatment#d15
  2. Stewart, David B. (2020). Anal fissure: Clinical manifestations, diagnosis, prevention. Uptodate. Retrieved Oct 1st, 2020, from https://www.uptodate.com/contents/anal-fissure-clinical-manifestations-diagnosis-prevention?search=anal%20fissure&source=search_result&selectedTitle=2~59&usage_type=default&display_rank=2

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