Anorectal Disorders 2008

Anorectal Disorders Armando G. Santos, MD, FPCS

Anatomy of the Anorectal Region

Anal Canal 

Anatomic anal canal 

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Dentate line separates canal from margin Based on differences in histology and lymphatic drainage Anal canal lies superior to dentate line Anal margin is inferior to dentate line

Surgical anal canal  

Anal verge separates canal from margin Margin is perianal skin just outside the verge

Anatomic Significance of Dentate Line Anatomy

Above dentate line Below dentate line

Innervation Autonomic Venous blood supply

Superior rectal vein into inferior mesenteric, portal system

Somatic

Middle rectal vein into internal iliac vein; inferior rectal vein into internal pudendal vein Lymphatic Inferior mesenteric, Inguinal lymph flow internal iliac lymph nodes nodes

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Incontinence: Clinical Evaluation

Ample history Examination  Inspection/palpation  Endoscopy Diagnostic tests:  Endoanal ultrasound  Manometry  Electromyography  Defecography

Causes of Fecal Incontinence CATEGORY Functional

Sphincter weakness

Sensory loss

MECHANISM

COMMON CAUSES

Fecal impaction; dilated Difficulty relaxing sphincter when internal anal sphincter defecating: drug side effect, idiopathic, spinal cord injury Diarrhea; rapid transit and/or large volume

Irritable bowel syndrome; infectious and metabolic causes of diarrhea

Cognitive or psychological defect

Dementia, psychosis, willful soiling

Sphincter muscle injury Anal surgery/Obstetric/Foreign body trauma Pudendal nerve injury

Obstetric trauma, diabetic peripheral neuropathy, multiple sclerosis

CNS injury

Spinal cord injury, CVA, multiple sclerosis

Afferent nerve injury: unable to detect rectal filling

Diabetic neuropathy, spinal cord injury, multiple sclerosis

Investigation of Fecal Incontinence

Incontinence: Management Medical  Stool transit/consistency modification  Biofeedback training of anal muscles  Surgical  Direct sphincter repair  Artificial sphincter implantation 

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Incontinence: Summary 

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Dx, including severity, of incontinence must be established Defect and underlying cause must be identified Treatment must be based on the confirmed pathology Medical or surgical management of incontinence produces much less than 100% success rate

Hemorrhoids: Essential Features 

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Vascularized “cushions” normally present in anal canal “Cushions” contain blood vessels, smooth muscle, elastic and connective tissue “Cushions” located in left lateral, right anterior, right posterior anal quadrants “Hemorrhoids” denote symptomproducing abnormal “cushions”

Hemorrhoids: Essential Features 

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Hemorrhoids classified as internal, external, or mixed Severity graded as:  First-degree  Second-degree  Third-degree  Fourth-degree

Hemorrhoids: A. Thrombosed external; B. Grade 1 internal; C. Grade 2 internal; D. Grade 3 internal; E. Grade 4 strangulated internal and thrombosed external 

Hemorrhoids: Clinical Diagnosis  

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Dx based on history, P.E., and endoscopy Manifestations: rectal bleeding, pain, mucus/fecal leakage, pruritus, prolapse associated with BM Complications: bleeding, thrombosis, strangulation, necrosis, perianal sepsis Other anorectal pathologies must be considered and excluded before

Hemorrhoids: Diagnostic Investigation    

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CBC Anoscopy Proctosigmoidoscopy Defecography – if with obstruction/rectal prolapse Colonoscopy – if hemorrhoids unimpressive with regards to presentation or colon CA risk significant

Hemorrhoids: Management  

Supportive Mx Definitive Mx:  Non-operative  Surgical

Hemorrhoids: Management 

Non-operative Mx  Rubber band ligation  Sclerotherapy  Infrared coagulation  Heater probe coagulation  Electrocoagulation

Rubber Band Ligation of Internal Hemorrhoids

Hemorrhoids: Management 

Surgical Mx  Open hemorrhoidectomy  Milligan-Morgan  Ultrasonic: Harmonic scalpel  Controlled electrical energy: LigaSure  Closed hemorrhoidectomy  Stapled hemorrhoidectomy

Closed Hemorrhoidectomy

Excision of Thrombosed External Hemorrhoid

Grade 4 Mixed Hemorrhoids: Stapled Hemorrhoidectomy

Stapled Hemorrhoidectomy

Stapling Device with Circumferential Excision of Anal Canal and Hemorrhoid Mucosa

Internal Hemorrhoids: Grading/Mx GRADE First degree Second degree

S/Sx Bleeding; no prolapse Prolapse with

spontaneous reduction leakage Third degree Bleeding, Prolapse requiring digital reduction Bleeding, leakage Fourth Prolapsed, cannot degree be reduced Strangulated

MANAGEMENT Dietary modifications Rubber band ligation Coagulation Dietary Hemorrhoidectomy modifications Rubber band ligation Dietary modifications Hemorrhoidectomy Dietary modifications

Hemorrhoids: Summary 

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Symptom-producing abnormal anal “cushions” Other diseases esp. CA must be ruled out before instituting Tx Supportive measures key to Mx of all cases Definitive Tx indicated for more advanced cases

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Anal Fissure: Essential Features

Linear ulcer in lower half of anal canal Posterior midline most common site Anterior midline fissure relatively common among females Pathogenesis possibly related to:  Internal sphincter hypertonia  Mucosal ischemia Bizarre site/number likely due to secondary fissures

Anal Fissure: Clinical Diagnosis    

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History and P.E. are key to Dx Main Sx: Pain during and after defecation Bleeding: Blood on stool or toilet tissue Triad for chronic cases:  Fissure  Sentinel pile  Hypertrophied papilla Digital exam may provoke sphincter

Posterior Anal Fissure

Acute Anal Fissure (Left); Chronic Anal Fissure (Right)

Anal Fissure: Diagnostic Investigation 

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Hx and P.E. usually adequate basis for Dx Endoscopy – to rule out malignant or inflammatory disease Biopsy of ulcer – in suspected secondary fissures

Anal Fissure: Management  

Supportive Tx for acute fissures Tx options for chronic fissures or failure of conservative measures:  Non-operative  Surgical

Anal Fissure: Management 

Non-operative Tx: Topical nitroglycerin  Topical calcium channel blocker  Botulinum toxin injection 

Anal Fissure: Management 

Surgical Tx: Partial lateral internal sphincterotomy  Anorectal advancement flap  Anal divulsion (Lord procedure) 

Sphincterotomy, if improperly done, may result in fecal incontinence

Partial Lateral Internal Sphincterotomy

Anal Fissure: Summary 

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Primary fissures likely produced by internal sphincter hypertonia and subsequent mucosal ischemia Primary fissures mostly located in posterior midline Partial lateral internal sphincterotomy surgical Tx of choice for chronic fissures Ulcers being secondary fissures should be considered and ruled out

Anorectal Abscess and Fistula: Essential Features 

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Primary suppuration and fistula result from non-specific cryptoglandular infection Abscess represents acute phase; fistula the chronic sequela Starts as anal gland infection in intersphincteric space (intersphincteric abscess) Secondary lesions may be due to malignancy, Crohn’s disease, hidradenitis suppurativa, TB, etc

Anorectal Abscess and Fistula

Anorectal Abscess and Fistula: Essential Features 

Types of abscess according to space invaded  Intersphincteric  Perianal  Intermuscular  Supralevator  Ischiorectal

Modes of Spread from Primary Locus in Intersphincteric Zone

Classification of Anorectal Abscesses

Formation of Acute Pararectal Abscess and Recommended Drainage

Planes for Circumferential Spread or “Horseshoeing” of Abscess

Anorectal Abscess and Fistula: Clinical Diagnosis      

Anal/perianal pain Perianal/rectal induration and swelling Purulent or bloody drainage Perineal sepsis External opening with mucopurulent or bloody drainage in anal fistula Palpable firm fistulous tract

Anorectal Abscess

External Opening of Anal Fistula

Classification of Anorectal Fistulas 1. 2. 3. 4.

Intersphincteric Trans-sphincteric Suprasphincteric Extrasphincteric

Main Anatomic Types of Fistulas

Intersphincteric Fistula

Transsphincteric Fistula: High Type

Anorectal Abscess and Fistula: Diagnostic Investigation  

Imaging studies not needed for uncomplicated abscesses and fistulas Imaging studies for complex or recurrent fistulas:  Fistulogram  Endoanal/endorectal ultrasound  CT scan  MRI

Endoanal UTZ of a Complex Fistula

MRI Fistulogram of a Supralevator Fistula

Anorectal Abscess: Management 

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Antibiotics not necessary for the average patient Surgical drainage – Tx of choice Prompt drainage and antibiotics indicated in diabetic or immunocompromised patients Fistulotomy may be delayed if internal opening not readily identified

Incision and Drainage of an Ischiorectal Abscess

Anal Fistula: Management    

Fistulotomy Seton placement Injection of fibrin glue Insertion of porcine small intestinal submucosa (SIS) plug

Goodsall Rule

Goodsall rule is of little use in complex or recurrent fistulas

Fistulotomy

Surgery of Transsphincteric Fistula with Horseshoe Spread

Seton Placement in High Type of Transsphincteric Fistula

Anal Fistula SIS Plug

Anorectal Abscess and Fistula: Summary 

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Primary lesions arise from cryptoglandular infection Imaging studies helpful in complex cases Surgical drainage primary Tx for abscesses Tx options for fistulas: fistulotomy, seton placement, fibrin glue injection, SIS plug Tx tailored so as to prevent fecal

Cancer of the Anal Canal and Anal Margin: Clinical Features/Evaluation 

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Canal cancers develop cephalad to anal verge Most canal tumors share similar behavior in clinical presentation, response to treatment, and prognosis Margin cancers arise in perianal skin adjacent to anal verge Viral infection (HPV, HIV) important factor

Cancer of the Anal Canal and Anal Margin: Clinical Features/Evaluation 

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Local symptoms: mass, bleeding, pruritus Distant manifestations: weight loss Perianal skin alterations DRE: tumor location/mobility/fixity; integrity of sphincter mechanism Endoscopy: size and location of tumor in relationship to dentate line/anal verge/anorectal ring

Cancer of the Anal Canal and Anal Margin: Clinical Features/Evaluation 

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P.E. for spread: organomegaly, groin adenopathy Tests for tumor extent and metastasis    

Chest radiography Endoanal ultrasound CT MRI

Anal Margin Tumors 

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Anal squamous cell carcinoma in situ (Bowen's disease) and anal intraepithelial neoplasia (AIN) Paget's disease Basal cell carcinoma Squamous cell carcinoma Verrucous carcinoma (giant condyloma acuminatum)

Anal Canal Tumors 

Epidermoid carcinoma:    

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Squamous Basaloid Cloacogenic Mucoepidermoid

Melanoma Adenocarcinoma

Mx of Anal Margin Tumors Bowen's Disease Accurate lesion mapping Wide local excision with flap repair as indicated Exclude locally invasive component or associated gynecologic malignancy Paget's Disease Accurate lesion mapping Wide local excision with flap repair as indicated Exclude underlying malignancy APR and chemotherapy/radiotherapy if

Mx of Anal Margin Tumors Basal Cell and Anal Margin Squamous Cell Carcinoma Local excision with clear margins Radiation or chemotherapy in poorprognosis lesions or recurrence as indicated Verrucous Carcinoma Wide local excision; APR if extensive Combined-modality Tx if transformation to squamous cell cancer has occurred

Mx of Anal Canal Tumors Epidermoid Cancer Combined-modality:

external-beam radiation Tx plus 5-FU plus mitomycin APR if incontinent or local Tx failure or recurrence after combined chemo and radiation therapy Triple-modality therapy in bulky T3 and T4 lesions (role of APR controversial)

Adenocarcinoma APR with 5-FU and radiation therapy as indicated Melanoma APR

if potentially curable Local excision if established metastases

Bowen's Disease

Paget's Disease

Basal Cell Carcinoma of Anal Margin

Verrucous Carcinoma Arising from Genital Warts

Anal Canal Amelanotic Melanoma

Anal Margin Squamous Cell Carcinoma

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