Anal fissure can be best diagnosed by
|A||Clinical examination and visualization|
a. A fissure in ano is a tear in the anoderm distal to the dentate line.
b. The pathophysiology of anal fissure is thought to be related to trauma from either the passage of hard stool or prolonged diarrhea.
c. A tear in the anoderm causes spasm of the internal anal sphincter, which results in pain, increased tearing, and decreased blood supply to the anoderm.
d. This cycle of pain, spasm, and ischemia contributes to development of a poorly healing wound that becomes a chronic fissure.
e. The vast majority of anal fissures occur in the posterior midline. Ten to 15% occur in the anterior midline.
f. Less than 1% of fissures occur off midline.
Symptoms and Findings :-
a. Anal fissure is extremely common.
b. Characteristic symptoms include tearing pain with defecation and hematochezia (usually described as blood on the toilet paper).
c. Patients may also complain of a sensation of intense and painful anal spasm lasting for several hours after a bowel movement.
d. On physical examination, the fissure can often be seen in the anoderm by gently separating the buttocks.
e. Patients are often too tender to tolerate digital rectal examination, anoscopy, or proctoscopy.
f. An acute fissure is a superficial tear of the distal anoderm and almost always heals with medical management.
g. Chronic fissures develop ulceration and heaped-up edges with the white fibers of the internal anal sphincter visible at the base of the ulcer.
h. There is often an associated external skin tag and/or a hypertrophied anal papilla internally. These fissures are more challenging to treat and may require surgery.
i. A lateral location of a chronic anal fissure may be evidence of an underlying disease such as Crohn's disease, human immunodeficiency virus, syphilis, tuberculosis, or leukemia.
a. Therapy focuses on breaking the cycle of pain, spasm, and ischemia thought responsible for development of fissure in ano.
b. First-line therapy to minimize anal trauma includes bulk agents, stool softeners, and warm sitz baths. The addition of 2% lidocaine jelly or other analgesic creams can provide additional symptomatic relief.
c. Nitroglycerin ointment (0.2%) has been used locally to improve blood flow but often causes severe headaches. Both oral and topical diltiazem have also been used to heal fissures and may have fewer side effects than topical nitrates.
d. Newer agents, such as arginine (a nitric oxide donor) and topical bethanechol (a muscarinic agonist), have also been used to treat fissures.
e. Medical therapy is effective in most acute fissures, but will heal only approximately 50 to 60% of chronic fissures.
f. Botulinum toxin causes temporary muscle paralysis by preventing acetylcholine release from presynaptic nerve terminals.
i. The aim of this procedure is to decrease spasm of the internal sphincter by dividing a portion of the muscle.
g. Approximately 30% of the internal sphincter fibers are divided laterally by using either an open or closed technique. Healing is achieved in more than 95% of patients by using this technique and most patients experience immediate pain relief.
h. Recurrence occurs in less than 10% of patients and the risk of incontinence (usually to flatus) ranges from 5 to 15%.