Current Management of Chronic Anal Fissure

Joint Hospital Grand RoundDepartment of Surgery,North District Hospital and Alice Ho Mui Ling Nethersole Hospital, NTEC

Anal Fissure

Definition: An elongated ulcer in the long axis of lower

anal canal

Pathology

A split of anoderm Associated with anal skin tag and hypertr

ophied anal papilla Occur at midline just distal to dentate lin

e 90% posterior, 10% anterior with less tha

n 1% simultaneous

Presenting Sym.

Pain

Bleeding

Discharge

Constipation

Examination

Gentle eversion of anus with limited digital examination

Anoscopy and rigid sigmoidoscopy under anaesthesia or deferred till healing occur

Anomanometry is not useful

Differential Dx.

Fissure occurs out of midline

1. Carcinoma of anus

2. Inflammatory bowels

3. Tuberculous ulcer

4. HIV/Herpes

– Biopsy should be taken for ulcer out of mid line or those fail to heal

Anorectal Physiology

Continence is maintained when intrarectal pressure are lower then the pressure generated by the resting internal and external sphincters.

Anorectal Physiology

Internal Sphincter: Smooth muscle Innervated by sympathetic (excitatory) and

parasympathetic fibre; (inhibitory) Constant contraction 85% of resting tone

Pathophysiology

ischemiaFail to heal

Fail to relax whenBO

Split of anoderm

Sphincter spasm

Forceful dilatation

Pathophysiology

Great pain associated with initial bowel motion

Patient ignores the urge to defecate Allows harder stool to form Self-perpetuating cycle

Management

good bowel habit

Relieve internal anal sphincter spasm

Management

Conservative: to regulate bowel habit, break the self-perpetuating cycle Stool softener Bulk forming agent Sitz-bath

90% healing rate (1 st epsiode) 60% healing rate for recurrent

Management

Sphincterotomy to break the vicious cycle induced sphinct

er spasm to reduce anoderm ischemia and to promo

te healing

Management

Conventional surgical sphincterotomy versus chemical sphincterotomy

Surgical sphincterotomy

1. Lateral internal anal sphincterotomy

Open v.s. Close

2. Fissurectomy with anoplasty: reserved for cases with prominent skin tag/recurrent anal fissure

• Longer healing time

Results and complication

Open Close P value

Persistence 3.4% 5.3% 0.27

Recurrence 10.9% 11.7% 0.77

reoperation 3.4% 4% 0.70

Lack of control of gas

30.3% 23.6% 0.06

Soiling 26.7% 16.1% <0.001

Accidental BM 11.8% 3.1% <0.001

Surgery good healing rate…… but rather high complication

Alternatives?

Sphincterotomy-chemical

Chemical sphincterotomy

Nitrogylcerin ointment

Botulinum toxin injection

Ca channel blocker/steriod……

Nitrogylcerin ointment As a source of nitric oxide

Inhibitory neurotransmitter cause internal anal sphincter relaxation

Commonly used 0.2-0.3% nitroglycerin

Local application by patient twice daily for 6/52

Result

Healing rate :60-75%

Side effect: 15-40% headache

Result

Parellada C et al. Randomized, prospective trial comparing 0.2 percent isosorbide dinitrate ointment with sphincterotomy in treatment of chronic anal fissure; a two years follow-up. Dis Colon rectum. 2004 ;47(4) 437-43

N=44 0.2% isosorbide dinitrate

surgery

5 weeks healing rate

67% 96%

10 weeks healing rate

89% 100%

30% decrease of maximal anal pressure in both arms

side effect 30% headache 15% incontinence

Botulinum Toxin

Mechanism of action: Action on internal anal sphincter as shown

in manometric studies( reducing both the resting and squeezing pressure)

Exact mechanism uncertain; inhibit acetylcholine release into synaptic gap causing neuormuscular blockade

More sustained action then Nitroglycerin ointment

How to inject?

Botulinum toxin A

Target: internal anal sphincter as palpated

No local anesthetic nor sedation required

How to inject?

at least 15 unit

? Probably better in multiple punture

Minguez M et al. Theraputic effects of different doses of botulinum toxin in chronic anal fissue

Dis Colon Rectum. 1999 Aug;42(8):1016-21

Where to inject?

anterior injection of the internal anal sphincter resulted in improved lowering of resting anal pressure and produced an earlier healing

Maria G et al. Influence of botulinum toxin site on healing rate in patients with chronic anal fissure. Am J Surg. 2000; 179(1):46-50.

Result:

Fissure healing rate: 70-90% at 2 months

Recurrence/non healing: 20%

No major side effect;

Giuseppe Brisinda and Maria G et al.

A comparison of botulinum toxin and topical nitroglycerin ointment for the treatment of chronic anal f

issure

N Engl J Med1999;341(2): 65-68

Result

RCT comparing comparing Botulinum vs Nitroglycerin ointment

N=50 Higher fissure healing rate at 8 weeks in

Botox group 96% vs 60% Significant lower resting anal pressure in

Botox group

B.Bulent Mentes et al.B.Bulent Mentes et al.

Comparison of Botulinum toxin injecComparison of Botulinum toxin injection and lateral internal sphincterototion and lateral internal sphincterotomy for the treatment of chronic anal fmy for the treatment of chronic anal f

issure issure

Dis Colon Rectum 2002. 46(2) 232-37Dis Colon Rectum 2002. 46(2) 232-37

N=111 Surgery Botox

Fissure healing rate at 2 months

82% 73.8%

At 6 months 98% 86.9%

recurrent 0 11.4%

Return of daily activities

14.8 days 1 day

complication 16% 0

Conclusion:

Internal anal sphincter spasm is the key to tackle chronic anal fissure

Traditional lateral sphincterotomy give excellent result in terms of fissure healing but bearing significant risk of incontinence

Conclusion

Result of chemical sphincterotomy is satisfactory, without the complication of lateral sphincterotomy and should be consider the first line treatment.

Botox injection give the most reliable result among different methods of chemical sphincterotomy