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Current Management of Chronic Anal Fissure
Joint Hospital Grand RoundDepartment of Surgery,North District Hospital and Alice Ho Mui Ling Nethersole Hospital, NTEC
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
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
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
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
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
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.
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