Management of Anal Fissure
Introduction:
The anal canal is a tube of about 3 cm in length, surrounded by internal and external sphincters, and collapsed by Levator ani muscle at the ano-rectal junction. The lining of the upper 2/3rd of the anal canal is derived from the ectoderm of the cloaca. It has a visceral innervation, and hence is relatively insensitive. The lining of the lower 1/3 rd is derived from the ectoderm of the proctoderm and has a somatic innervation via the inferior rectal nerve. Painful sensation may arise from the perianal skin, the anoderm or the surrounding muscles. Anal Fissure: It is a split at the junction of perianal skin and the anoderm. The lesion is a longitudinal tear of the anoderm ie of the lower 3rd of the anal canal, extending from the dentate line to the anal margin. It almost always lies in the midline. Anal fissure may be superficial or deep. If superficial the floor is formed by the longitudinal muscle fibers lying in the sub mucosa. If deep, the base consists of the transversely running white fibers of the internal sphincter.
Site:
The sex ratio is almost equal. In Male about 90% are posterior and 10% anterior. It is due to unequal support of rectal mucosa over the racket shaped attachment of external sphincter in coccyx. In Female anterior fissures are more common, due to unequal support of the rectal mucosa by a damaged pelvic floor.
Age Group:
Commonest in young adults. Occasionally occurs in infants and children, rare in the elderly. In children there is usually associated constipation.
Etiology:
Etiology is unknown.
High resting anal fissure: According to this theory chronic anal fissure is thought to result from a non healing laceration of the anoderm due to constipation. However only 20 % of patients give a history of constipation.
Ischaemic origin: Traumatic breech of anoderm normally heals but patients with pre existing raised sphincter tone will have impaired microvascular perfusion of the posterior mid line anoderm and will heal poorly. This theory supported by the postmortem angiographic study shows minimal arterial connection between the terminal branches of the bilateral inferior rectal arteries at the posterior mid line. So, the chronic anal fissures are most certainly a result of the combined effect of a hypertonic anal sphincter and a decreased ano dermal blood flow residing in a non-healing ischaemic ulcers of the anoderm.
Clinical features:
Pain – 90 % 0f the patients have pain on defecation and the pain is typically severe and it may be last 20 to 30 minutes, but seldom longer. So, the fear of defecation may lead to constipation. Scybala form and the inevitable act of defaecation is then accompanied by excruciating pain and reopening of the fissure.
Bleeding is frequently occurs.
Other symptoms are?
- Pruritus 50 %
- Watery discharge 20 %
- Constipation 20 %
Diagnosis:
Investigations have a limited role. Accurate history taking and examination is essential.
History should include?
- Character of the pain.
- Relationship to defecation.
- Presence or absence of bleeding or discharge.
- Change in bowel habit.
- Presence of swelling – skin tag or papilla at the anal opening.
Examination should include
- Inspection of the anal canal in good light.
- Digital examination is contra indicated to avoid severe pain.
- Full ano rectal examination with proctoscopy and sigmoidoscopy should be done only under anesthesia.
Differential Diagnosis:
- Crohn’s disease – appearance of fissure is atypical, the lesion being indolent and indurated – often having multiple fissures at any position and large oedematous skin tags.
- Ulcerative colitis — Fissure is sometimes associated and it is mild form.
- Tuberculous ulcer of the anal canal – it is very rare nowadays and it is a chronic indurated lesion confirmed by biopsy.
- Syphilitic ulcer – almost painless fissure – most often the fissure extends out on to the skin or higher above the muco cutaneous junction.
- Lympho granuloma venerum is rare.
- Carcinoma of the anal margin . It does not usually have the typical appearance nodular or more raised.
Treatment:
It may be conservative or operative. Aim of the treatment is to relieving spasm of the internal sphincter.
Conservative treatment: Uncomplicated recent fissures without sphincteric spasm respond to conservative treatment. Half the simple acute fissures without features of chronicity heal spontaneously. If pain is not severe local anaesthetic ointment, anti-inflammatory drugs and stool softeners may help for healing. Glyceryl trinitrate ointment 0.2 % ointment has recently been used successfully, since this causes a reduction in anal canal pressure and improves healing. Recently it was found that injection of Botulinum Toxin A is more effective than topical nitroglycerin.
Operative treatment: Resistant, recurrent or chronic fissures require operative intervention. Operation includes , excision of the irritable ulcer and division of at least part of the muscular ring on which it lies. ( external sphincter is the muscular ring ) Spincterotomy entails dividing the internal sphincter unto the level of dentate line. Posterior Spincterotomy: Division of the sphincter through the base of the fissure is of no longer favored since disturbance of continence. Lateral Spincterotomy: may be performed as an open operation or closed as a subcutaneous Spincterotomy. In the open operation internal sphincter is identified through a small circumferential incision and divided under direct vision. Sub-cutaneous Spincterotomy is performed by placing a No. 15 scalpel blade into the groove between the internal and external sphincters and turns the scalpel medially and divide the internal sphincter
All these surgical procedures resulting incontinence of flatus or feces or may resulting haematoma or perineal abscess. Anal Dilatation: Although the surgical treatment of lateral internal Spincterotomy is the current treatment of choice for chronic anal fissures in most of the centers, since it is associated with significant risk of anal incontinence in 30 % of patients sphincter preserving techniques may be important to avoid the anal incontinence.
In our experience of more than 10,000 cases of anal dilatation for the past more than 25 years since 1971 to till date, simple anal dilatation has been effective. The procedure of anal dilatation is much simpler than Lords and it is purely an outpatient procedure. Under short GA anal canal and the lower rectum are dilated by introducing two fingers in the 12 o clock and two fingers of the other hand in the 6 o clock position and dilate for one minute. Then the position of the fingers is changed into 3 & 9 o clock position and dilate for another one minute. The pressure should be maintained through out for two minutes.
Postoperatively we allow the patient to take normal diet with high residue like banana and greens so that the patient passes free soft bulky motion which automatically dilates the anal canal periodically. For the first 3 to 4 days we advice to take laxative like liquid paraffin one Oz at bedtime to avoid constipation.
This anal dilatation may help in rupturing the fibrous band known as Pecton Band As per MILES Theory, which was present just above the Hiltons line. This is nothing but the fibrous band V sub mucous fibrosis due to congestion of the hemorrhoid veins and super added infection. As per the Lord!|s procedure neither periodic dilatation by the surgeon nor self-dilatation by the patient. is not required, since we are commencing the high residue diet in the same day or the first postoperative day resulting the soft bulky motion will acts as a natural dilator. None of our patients developed incontinence postoperatively and a small percentage developed recurrence due to the negligence of the advised dietary regime and developed constipation.
To Conclude:
With our vast experience we have found that,
- It is purely an out patient procedure and the patient is fit for normal routine work within 2 to 3 days.
- No further hospital visit is required for periodic dilatation as per Lord’s procedure.
- No complication like anal incontinence.
- Postoperative pain is either absent or minimum when anal dilatation is performed as an adjuvant procedure for hemorrhoids and perianal abscess.
This lecture was delivered for M S General Surgery Postgraduates of Karnataka and and practicing Surgeons in Bangalore at Manipal Hospital Bangalore on March 2000 Under the presidenship of Dr.M.G.BHAT
This lecture was delivered for M S General Surgery Postgraduates of Karnataka and and practicing Surgeons in Bangalore at Manipal Hospital Bangalore
