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

2. Anal Fissure Definition:
An elongated ulcer in the long axis of lower anal canal

3. Pathology A split of anoderm
Associated with anal skin tag and hypertrophied anal papilla
Occur at midline just distal to dentate line
90% posterior, 10% anterior with less than 1% simultaneous

4. Presenting Sym.
Pain
Bleeding
Discharge
Constipation

5. Examination Gentle eversion of anus with limited digital examination
Anoscopy and rigid sigmoidoscopy under anaesthesia or deferred till healing occur
Anomanometry is not useful

6. Differential Dx. Fissure occurs out of midline
Carcinoma of anus
Inflammatory bowels
Tuberculous ulcer
HIV/Herpes
Biopsy should be taken for ulcer out of mid line or those fail to heal

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

8. Anorectal Physiology Internal Sphincter: Smooth muscle
Innervated by sympathetic (excitatory) and parasympathetic fibre; (inhibitory)
Constant contraction
85% of resting tone

9. Pathophysiology

10. Pathophysiology Great pain associated with initial bowel motion
Patient ignores the urge to defecate
Allows harder stool to form
Self-perpetuating cycle

11. Management
good bowel habit
Relieve internal anal sphincter spasm

12. 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

13. Management Sphincterotomy
to break the vicious cycle induced sphincter spasm
to reduce anoderm ischemia and to promote healing

14. Management
Conventional surgical sphincterotomy versus chemical sphincterotomy

15. Surgical sphincterotomy
Lateral internal anal sphincterotomy
Open v.s. Close
Fissurectomy with anoplasty: reserved for cases with prominent skin tag/recurrent anal fissure
Longer healing time

16. Results and complication
Open
Close
P value
Persistence
3.4%
5.3%
0.27
Recurrence
10.9%
11.7%
0.77
reoperation 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%

17. Surgery good healing rate…… but rather high complication
Alternatives?

18. Sphincterotomy-chemical
Chemical sphincterotomy
Nitrogylcerin ointment
Botulinum toxin injection
Ca channel blocker/steriod……

19. Nitrogylcerin ointment
As a source of nitric oxide
Inhibitory neurotransmitter cause internal anal sphincter relaxation
Commonly used % nitroglycerin
Local application by patient twice daily for 6/52

20. Result
Healing rate :60-75%
Side effect: 15-40% headache

21. Result 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
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 ;47(4)

22. 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

23. How to inject? Botulinum toxin A
Target: internal anal sphincter as palpated
No local anesthetic nor sedation required

24. 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 Aug;42(8):

25. 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.

26. Result: Fissure healing rate: 70-90% at 2 months
Recurrence/non healing: 20%
No major side effect;

27. Giuseppe Brisinda and Maria G et al.
A comparison of botulinum toxin and topical nitroglycerin ointment for the treatment of chronic anal fissure
N Engl J Med1999;341(2): 65-68

28. Result RCT comparing comparing Botulinum vs Nitroglycerin ointment
Higher fissure healing rate at 8 weeks in Botox group 96% vs 60%
Significant lower resting anal pressure in Botox group

29. B.Bulent Mentes et al.
Comparison of Botulinum toxin injection and lateral internal sphincterotomy for the treatment of chronic anal fissure
Dis Colon Rectum (2)

30. N=111
Surgery
Botox
Fissure healing rate at 2 months
82%
73.8%
At 6 months
98%
86.9%
recurrent
11.4%
Return of daily activities
14.8 days
1 day
complication
16%

31. 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

32. 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