1. Treatment for Anal fistula
Dr. Wong Siu Wang
North District Hospital
Joint Hospital Surgical Grand Round
Sept 2006

2. Classification Parks classification High vs Low Simple vs Complex
Intersphincteric
Trans-sphincteric
Supra-sphincteric
Extra-sphincteric
High vs Low
Simple vs Complex
BJS 1976;63:1-12

3. Etiology Crytogenic Inflammatory bowel disease Malignancy Tuberculosis
Pelvic sepsis

4. Etiology Crytogenic Inflammatory bowel disease Malignancy Tuberculosis
Pelvic sepsis

5. Treatment of Anal fistula
Fistulotomy
Fistulectomy
Advancement flaps
Seton (loose, cutting, chemical)
Fibrin glue
Radiofrequency

6. 1. Fistulotomy Standard treatment for low type fistula
Recurrence rate ~5% - 10%
Minor incontinence rate ~6% - 26%
Stage fistulotomy for high type fistula
Recurrence rate ~5% – 8%
Minor incontinence rate ~50%
BJS 1995;82:895-7
BJS 1991;78:

7. Fistulotomy (New Modification)
Marsupialisation
Suturing the divided wound edge to the edges of the curetted fibrous track
Results in smaller wound and faster healing
Colorectal Dis 2006;8:11-4
BJS 1998;85:

8. 2. Fistulectomy Argument against fistulectomy
RCT of Fistulectomy vs Fistulotomy
Greater tissue loss leads to delayed healing
Similar recurrence rates
BJS 1985;55:23-7

9. Fistulectomy Argument supporting fistulectomy Modification:
Complete specimen for histology
Reduces risk of missing secondary tracks
Similar incontinence rate
Modification:
Core out technique
Fistulectome

10. Fistulectome
The fistulectome: a new device for treatment of complex anal fistulas by “Core-Out” fistulectomy. Dis Colon Rectum 2003;46:

11. Fistulectome Device for core out fistulectomy
Remove 2mm thickness of fistula tract
Limited experience and results
Dis Colon Rectum 2003;46:

12. 3. Endorectal advancement flap
Treatment for high type fistula
Close the internal opening with flap
Mucosal flap for proximal fistula, anocutaneoeus flap for distal fistula
Contra-indication: acute sepsis, large internal opening, heavily scarred rectum

13. Endorectal advancement flap
Results in high type fistula
Heterogenous, depend on length of FU
Recurrence rate ~20% - 60%
Incontinence rate ~18.7%
Int J Colorectal Dis 1994;9:153-7
Int J Colorectal Dis 2006 Mar 15

14. 4. Seton
Loose Seton
Cutting Seton
Chemical Seton

15. i. Loose Seton
Drainage of sepsis before definitive treatment (eg. Staged fistulotomy)
Primary treatment for complex fistula

16. Loose Seton Procedure in St Mark’s Hospital
Tracks and extensions outside sphincter laid open
passage of Seton thro’ primary track across the external sphincter and tied loosely
Outpatient review, remove Seton at 2-3 months if wound healed

17. Loose Seton Result for treatment of complex fistula
Success rate 44% - 78%
Minor incontinence rate 17% - 36%
Int J Colorectal Dis 1989;4:247-50
BJS 1990;77:

18. ii. Cutting Seton Analog to staged fistulotomy
Cutting the fistula track with tightening of Seton
Balance between healing speed vs continence
Material: silk, braided polyester, rubber band, Penrose drain

19. Cutting Seton Results are heterogenous Average cutting time ~14-20 wks
Recurrence rate ~5% (0-29%)
Minor incontinence rate ~50%
New Modification
Snug Seton

20. Snug Seton T M Hammond et al 1mm elastic Seton
Silicon nerve vessel retractor
Slow fistulotomy
T M Hammond et al
29 patients idiopathic fistula (~38% high type)
Median cutting time 24 wks
No recurrence
Minor incontinence rate ~25%
Colorectal Dis 2006;8:328-37

21. iii. Chemical Seton Kshara sutra, derived from plants (Ayurveda)
Antibacterial, anti-inflammatory properties, alkaline
Weekly insertion
Slowly cut though the tissues

22. Chemical Seton
RCT comparing chemical Seton with fistulotomy in low type fistula
More painful with chemical Seton but no difference in healing time, complications or functional outcome
Tech Coloproctol 2001;5:137-41

23. 5. Fibrin glue Fibrinogen solution +/- antibiotics Before injection
Promote healing thro’ fibroblast migration and activation, formation of collagen meshwork
Before injection
Curettage all granulation tissue and debris
Contraindication: acute sepsis

24. Fibrin glue Results variable For complex fistula For simple fistula
Successful rate ~50%
Septic complication 3%
Dis Colon Rectum 2005;48:
For simple fistula
RCT fibrin glue vs conventional treatment for anal fistula
42 patients
No advantage for fibrin glue over fistulotomy in simple fistula
Dis Colon Rectum 2002;45:

25. 6. Radiofrequency Radiofrequency scalpel Fistulotomy/ fistulectomy
High frequency 4MHz radiowave
Mode: cutting, coagulation, fulgurate, bipolar

26. Radiofrequency

27. Radiofrequency Principle Transmit radio wave to tissue
Cause tissue damage by intracellular heating
Low cutting temperature 60 – 900C (vs 750 – 9000C in diathermy)
More precise cutting, less surrounding tissue damage, less tissue edema and pain

28. Radiofrequency Two small scale randomized trial
Diathermy fistulotomy vs Radiofrequency fistulotomy/ fistulectomy in low type fistula
Less post-operative pain
Earlier return to work
Shorter wound healing time
No difference in complication & recurrence
Eur Rev Med Pharmacol Sci 2004;8:111-6
Rom J Gastroenterol. 2003;12:287-91

29. Treatment of Anal fistula
SUMMARY

30. Simple fistula Standard treatment Other treatments
Fistulotomy +/- Marsupialisation
Fistulectomy
Other treatments
Radiofrequency fistulotomy/ fistulectomy (emerging evidence)
Fibrin glue (lower healing rate, no advantage)
Seton (prolong healing)

31. Complex fistula Initial treatment Other treatment
Loose Seton (low incontinence rate)
Other treatment
Advancement flaps (variable result)
Fibrin glue (variable result)
Cutting Seton (high incontinence rate)
Snug Seton (need more evidence)
Stage fistulotomy (high incontinence rate)

32. Treatment for Anal fistula
~ End of presentation ~

33. Treatment of anal fistula
Question and Answer

34. Definition (variable)
High type
Involving the anorectal ring
Internal opening above dentate line
Complex type
Multiple side branches
Chronic inflammatory disease (Chron’s)
Previous operation/ irridation

35. Incontinence scoring system
Cleveland Clinic scoring system
Wexner Continence grading scale
Material: solid, liquid, gas
Frequency: rare to always

36. Fistulotomy and immediate reconstruction
Reconstruct the divided musculature and primary wound closure
For low type fistula
Study from Parkash et al
120 patients
98% low type fistula
88% wound healed by 2 weeks
Recurrence rate 4%
ANZJ Surg 1985;55:23-7

37. Fistulotomy and immediate reconstruction
For complex fistula
Prospective study by Perez F et al
35 patients with complex anal fistula
85.7% high trans-sphincteric, 11.4% supra-sphincteric, 2.9% extra-sphincteric
31.4% incontinent patients reported improvement in continence scores
12.5% continent patients reported minor alternations of continence (Wexner Continence Scale <4)
Recurrence rate 5.7%
J Am Coll Surg 2005;200: