Anorectal Diseases [Written Summary] PDF

 Bleeding and pain  fissure or anal carcinoma

HEMORRHOIDS (PILES)

Heme = blood

Rhoids= flowing Piles= ball

* it is the commonest cause of rectal bleeding ANATOMY:

Within the anal canal there are anal cushions which contain blood vessels (arterioles, venues, A-V fistula) muscles and connective tissues.

These cushions are found at the ano-rectal junction above the dentate line.

They lie in the left lateral, right anterior and right posterior positions relative to the anal canal (3, 7, 11 o’clock position) when the pt. lies in the lithotomy position.

In-between these 3 primary haemorrhoids (cushions) there may be smaller secondary ones.

PATHOPHYSIOLOGY:

Anal cushions may become congested as a result of increased intra-abdominal pressure (straining) or by compression of superior rectal vein by a carcinoma in the rectum or by the uterus of a pregnant women.

CAUSES:

1- carcinoma of the rectum: may compress or cause

thrombosis of the superior rectal vein  piles

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2- pregnancy: pregnant uterus compress superior rectal vein also progesterone relaxes the smooth muscles of the veins causing an increase in the pelvic circulating volume.

3- Chronic constipation: straining increases intra-abdominal pressure. Hard stool passage traumatizes the cushion’s wall.

4- Also, heart failure, excessive use of laxatives and portal

HTN are causes.

*internal and external haemorrhoids are differentiated by their anatomical origin in the anal canal.

INTERNAL HAEMORRHOIDS: -develops above the dentate line. -covered by anal mucosa.

-lacks sensory innervation (painless) -bright red or purple in color.

EXTERNAL HAEMORRHOIDS: -arise below the dentate line. -Covered by St. sq. epith.

-innervated by the inferior rectal nerve.

 Internal H. drains into sup. Rectal veins  portal system  External H. drains into inf. Rectal veins  I.V.C.

GRADING HAEMORRHOIDS :

Internal H. are classified by the degree of tissue prolapse into the anal canal.

GRADE 1: they are confined to the anal canal with minimal bleeding or maybe asymptomatic but do not prolapse.

GRADE 2: they prolapse on defecating or straining then reduce spontaneously.

GRADE 3: prolapse with or without straining and require manual reduction.

GRADE 4: chronically prolapsed and if reducible fall out again. Others fall out of the anus and are irreducible (strangulated)  surgical emergency.

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PREDESPOSING FACTORS:

Most H. are idiopathic, but they may be precipitated by factors that produce sup. Rectal vein congestion.

1- Compression by any pelvic tumour or pregnant uterus. 2- Cardiac failure or portal HTN. 3- Chronic constipation.

4- Use of purgatives (laxatives) excessively. 5- Rectal carcinoma.

SYMPTOMS:

Grade 1 usually are asymptomatic or with minimal bright red bleeding on defecation.

1-bleeding:

-the main and earliest symptom

-starts as bright red bleeding on the surface of the stool or on the toilet paper.

-it may continue intermittently for years or months.

-it often increases in frequency and severity until a steady drip of blood accompanies defecation.

2-prolapse:

-a much later symptom

-starts transiently on defecation, but occurs with increasing frequency until 3 rd degree H. develop.

3-discharge:

-a mucous discharge accompanies a prolapsed pile.

-occurs when the columnar mucosa of the upper anal canal is exposed.

4-pruritis: this will follow the discharge.

5-pain: they are painless unless if they are complicated by a thrombus to a thrombosed pile.

SIGNS: the pt. should be in the left lateral position.

INSPECTION:

-1 st degree H. show no outward abnormality

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-2 nd degree H. may show the skin covered components when the buttocks are separated or piles may prolapse when the pt. strains. -3 rd degree H. shows the red anal mucosa in their position (3,7,11)

DIGITAL EXAMINATION: internal H. can’t be felt unless they are thrombosed or in the long standing thickened piles. Browes book says don’t do PR.

PROTOSCOPY: it is the key investigation.

– When the protoscope is slowly withdrawn just below the anorectal ring the H. will bulge into the lumen of the protoscope.

– The pt. is asked to strain during the withdrawal so the vascular engorgement is produced and the degree of prolapse can be determined.

*don’t forget abdominal examination.

 Thrombosed piles: the skin around the anus is swollen and edematous in relation to the pile bearing areas.

INVESTIGATIONS:

1-sigmoidscopy: essential to exclude co-exclude rectal pathology as carcinoma or polyps.

2-barium enema: indicated when sigmoidscopy and protoscopy can’t explain the symptoms.

3-CBC: anemia, rarely happen in longstanding piles.

DDx:

Anal or rectal cancer. Redunculated polyps. Rectal prolapse.

Anal fissures or fistula or hematoma – if painful-

COMPLICATIONS:

1- anemia: rarely may follow a sever or continuous bleeding 2- Strangulation: when a prolapsing pile become gripped by

the external anal sphincter.

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3- Thrombosis: results from an occlusion of the venous return by a strangulated pile. It is swollen, painful, tense and dark. 4- Ulceration: superficial ulceration of the exposed mucous

membrane.

5- Gangrene: when strangulation is so tight to constrict the

arterial supply of the H.

6- Suppuration: uncommon. Due to infection of the

thrombosed pile.

7- Fibrosis: after the thrombosis, the H. may be converted into

fibrous tissue.

TREATMENT:

1-first degree H.: bulk laxatives and high dietary fibers maybe enough  to decrease the constipation

2-injection therapy (sclerotherapy):

-for the 1 st degree and early 2 nd degree H.

-3-5 ml of 5% phenol in almond oil is injected through a special syring to the base of the pile or just above the anorectal ring. -It is a painless procedure if done properly because the high anal

canal area is painless.

-Bleeding should stop within 24-48 hours.

-Procedure may be repeated after a few weeks if necessary.

3- Rubber band ligation:

-effective with 1 st and 2 nd degree H.

-a small o-ring rubber band applied to constrict the mucosa at the base. This will lead to strangulation of the pile and subsequent sloughing of the pile over a period of 10 days or so.

4-infra-red photocoagulation.

5-cryotherapy: a cryoprope is applied to the overlying mucosa.

6-stretching of the anal sphincter: it improves venous drainage and decrease the need for straining. Overstretching may lead to anal incontinence.

7-haemorrhoidectomy:

Necessary for the 3 rd degree H. or in prolapsed thrombosis. Complications of the procedure:

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Anal stenosis, acute urinary retention, post-operative hmg.

CARCINOMA OF THE RECTUM

 Carcinoma of the rectum accounts for approximately one

third of all tumours of the large intestine.

 Predisposing factors are pre-existing adenomas, familial

adenomatous polyposis and ulcerative colitis.

 Diagnosis is made on the basis of: the history, rectal

examination, sigmoidscopy and biopsy finally.

 75% occur in the lower part of the rectal ampulla  papilliferous or a simple ulcer with everted edges.

 25% in the upper part of the rectum  annular in shape.  90% or rectal cancers can be felt with a finger during PR.

MACROSCOPIC APPEARANCE: It may be as follows:  papilliferous

 ulcerating  commonest

 stenosing  at rectosigmoid  colloid

MICROSCOPIC APPEARANCE: *90% are adenocarcinoma