ANAL CANAL Dr. Tanuj Paul Bhatia

ANATOMY

Most distal portion of the alimentary canal.

Extends for a distance of about 3 cm from the anorectal ring to the hairy skin of the anal verge.

Anus provides continence for flatus and faeces.

White line

Dentate line

Anal crypts and columns

Anal gland

Internal hem. plexus

Int. sphincter

External sphincter

NERVE SUPPLY

Below the dentate line, cutaneous sensations conveyed by afferent fibers in the inferior rectal nerves.

Above the dentate line : parasympathetic fibres

BLOOD SUPPLY

Arterial supply : The middle rectal arteries arise from the internal

iliac arteries. The inferior rectal arteries, branches from the

internal pudendal arteries. Venous drainage :

Above dentate line : Int. hem. plexus sup rectal vein Inf. Mesenteric vein

Below dentate line : Ext. hem. Plexus Middle rectal vein Int. iliac vein OR Inf. Rectal vein pudendal vein Int. iliac vein

SPHINCTER COMPLEX

External sphincter Extension of levator ani around anorectum Voluntary sphincter Supplied by pudendal nerver 3 compnents :

Subcutaneous Superficial Deep

INTERNAL SPHINCTER

Involuntary sphincter Innervated by autonomic nervous

system Formed by extension of rectal

musculature

FORMATION OF ANAL SPHINCTERS

FECAL INCONTINENCE

The principal function of the anal canal is the regulation of defecation and maintenance of continence.

Evaluated by manometry, defecography and electromyography.

CAUSES

MANAGEMENT OF FECAL INCONTINENCE

HEMORRHOIDS

DEGREE OR STAGEWISE CLASSIFICATION 1st degree: bleeding 2nd degree: protrusion but spontaneous

reduction 3rd degree: protrusion that requires

manual reduction 4th degree: irreducible protrusion

External 1st degree

2nd degree

3rd degree

4th degree

TREATMENT OPTIONS

Slerotherapy Rubber band ligation Open hemmorhoidectomy Closed hemmorhoidectomy Stapled hemmorhoidectomy

BAND LIGATION

HEMMORHOIDECTOMY

STAPLED HEMORHOIDECTOMY

DOUGHNUT OF HEM. TISSUE

THROMBOSED EXTERNAL HEMORRHOID

Painful Self curing 5 day

DISEASE

ANAL FISSURE OR FISSURE-IN-ANO

Linear ulcer of lower half of anal canal Posterior fissure is most common Anterior fissures commoner in women

than men Fissure in any other location : suspect

Crohn’s disease Hydradeinitis suppuritiva STDs

POSTERIOR FISSURE-IN-ANO

PATHOGENESIS

passage of large, hard stools, which may be the initiating factor;

inappropriate diet; previous anal surgery; childbirth; and laxative abuse.

SYMPTOMS

With defecation, the ulcer is stretched, causing pain and mild bleeding.

TYPES

Acute fissure in ano Chronic fissure in ano

ACUTE FISSURE IN ANO

Short history Painful No sentinel pile on examination Managed conservatively

CHRONIC FISSURE IN ANO

Recurrent acute fissure Associated with sentinel pile Can be treated conservatively initially

but may require surgery

Sentinel pile : a skin tag formed due to chronic

inflammation and fibrosis

TREATMENT

Non surgical Surgery

AIM: To increase the blood supply to promote healing of the ulcer/fissure

NON SURGICAL TREATMENT

Stool bulking agents Hot tub baths/ Sitz bath Local ointments

Lignocaine Nitroglycerine

Dietary modifications Botox injections

SURGICAL

Sphincterotomy Internal anal sphincter is cut to relieve the

spasm and in turn increase blood supply to the fissure

Midline sphincterotomies cause key hole defects, hence lateral sphincterotomy is done.

2 types : Open Closed

OPEN SPHINCTEROTOMY

CLOSED SPHINCTEROTOMY

ANAL SEPSIS AND FISTULAE

Anorectal abcess – acute form of anal sepsis Fistula in ano – chronic form of the disease

process

Anal fistula : communication between an internal opening in the anal canal and an external opening through which an abscess drained.

ETIOLOGY

Infection of obstructed anal glands : Most common cause

Trauma Foreign body Tuberculosis Actinomycosis Inflamatory bowel disease

CLASSIFICATION

TREATMENT

ANORECTAL ABCESS

PERIANAL ABSCESS

Results frtom suppuration of anal gland or suppuration of a thrombosed external pile

Lies in the region of subcutaneous portion of external sphincter

CLINICAL FEATURES

Severe pain in perianal region Difficulty in sitting Tender smooth and soft swellling in the

perianal region

TREATMENT

Sitz bath Antibiotics Drainage under GA

ISCHIORECTAL ABCESS

Due to extension of intermuscular abcess through external sphincter

Can be blood born as well Fat in fossa more prone for infection as

it is least vascularized Both these fossa are connected one

fossa infection may lead to the infection on other side HORSE SHOE ABCESS

CLINICAL FEATURES

Tender, indurated, brawny swelling in the skin over ischiorectal fossa

Fever Swelling is not well localized so it is

difficult to elicit fluctuation.

TREATMENT

Cruciate incision and drainage Pus for c/s Look for any internal opening (for

presence of internal fistula)

SUBMUCOUS ABCESS

Occurs above the dentate line Can be drained with a sinus forceps

through proctoscope

FISTULA IN ANO

Etiology Cryptoglandular sepsis(most common) Trauma Crohn’s disease Malignancy Radiation

tuberculosis,actinoymycosis

CLINICAL FEATURES

Persistent drainage from internal or external opening

Indurated tract can be palpable on per rectal examination .

External opening easily found but finding the internal opening can be a challenge

GOODSALL’S RULE

‘In general, fitulas with external opening anteriorly connect to internal opening by a short,radial tract.’

Fistulas with external opening posteriorly track in curvilinear fashion to posterior midline.

EXCEPTION : anterior external opening >3cm from anal verge usually follow curved track to posterior midline

CLASSIFICATIONS OF FISTULA IN ANO

1. Park’s classification2. High and low fistula in ano3. Simple and complex fistula in ano

PARK’S CLASSIFICATION

1.Intersphincteri

c

2.Transsphincteri

c

3.Suprasphincter

ic

4.Extrasphincteri

c

SPECIAL INVESTIGATIONS

Trans rectal ultrasound (TRUS)/ Endoanal ultrasound

Fistulogram MRI

SURGICAL MANAGEMENT

Fistulotomy Fistulectomy Setons

FISTULOTOMY

‘Laying open of the fistula tract from its termination to source’

Applied mainly to intersphincteric and transphincteric fistula involving less than 30% of voluntary muscle.

Staged sphincterotomy : part of sphincter is divided and rest tied upon by a seton.

FISTULECTOMY

Coring out of the fistula

SETONS

Latin for Bristle Loose and tight setons : depending

upon the intent of cutting through the muscle.

After tying, these are tightened in intervals of weeks.

‘Cheese wire cutting through ice’ They gradually cut through the muscles

without springing them apart

STAGED FISTULOTOMY

RECENT ADVANCES

1. Advancement flaps2. Tissue glues

PILONIDAL SINUS(JEEP BOTTOM)

Pilus= hair , nidus = nest Of infective origin Occurs in sacral region between the

buttocks Other sites : umbilicus, web spaces of

fingers(in barbers)

PATHOLOGY

Hair penetrate skin causing dermatitis and infection

Persistent infection leads to sinus formation

Primary sinus : midline Secondary sinuses : paramedian

CLINICAL FEATURES

Serosanguinous or purulent discharge Throbbing and persistent pain Sometimes tender swelling in the

midline Tufts of hair may be seen in the

opening of sinus

TREATMENT

Excision of the sinuses Laying open the sinus Z- plasty Rotation flaps Bescom’s operation Karydaki’s operation

ANAL INTRAEPITHELIAL NEOPLASIA

Virally induced dysplasia Risk factors : anoreceptive intercourse

and HIV Usually patients are asymptomatic Based on degree of dysplasia : AIN I,

AIN II, and AIN III AIN II and III have chances of

progressing to invasive carcinoma

CLINICAL FEATURES

30% asymptomatic Suspicious areas are raised, scaly,

white, erythematous, pigented or fissured.

MANAGEMENT

Multiple mapping biopsies Excision followed by colostomy or flaps Topical imiquimod or retinoids have

some effect on progression of diesease.

NON MALIGNANT STRICTURES

1. Spasmodic : due to anal fissure.2. Organic :

1. Postoperative2. Irradiation stricture3. Senile anal stenosis4. Lyphogrnuloma inguinale5. Inflamatory bowel disease6. Endometriosis

CLINICAL FEATURES

Increasing difficulty in defecation ‘Pipe stem’ stools. Stricture can be palpated as annular or

tubular on DRE.

TREATMENT

Dilatation by bougies. Anoplasty. Colostomy. Rectal excision and coloanal

anastomosis.

MALIGNANT TUMORS

Below dentate line : SCC Above dentate line : basaloid,

cloacogenic or transitional carcinomas.

SQUAMOUS CELL CARCINOMA

Risk factors : HPV infection AIN Immunosuppression

CLINICAL FEATURES

Pain Bleeding Pruritus Fecal incontinence as a result of

sphincter invasion. Palpable as indurated, irregular, tender

ulcers.

MANAGEMENT

Primary treatment : chemoradiotherapy CMT(combined modality treatment) 5-FU with mitomycin C or cisplatin

Resection indicated in Small marginal tumors Persistent or recurrent disease followed

by colostomy

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