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

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

Etiology Crytogenic Inflammatory bowel disease Malignancy Tuberculosis Pelvic sepsis

Etiology Crytogenic Inflammatory bowel disease Malignancy Tuberculosis Pelvic sepsis

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

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;78:1159-61

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;85:105-107

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

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

Fistulectome The fistulectome: a new device for treatment of complex anal fistulas by “Core-Out” fistulectomy. Dis Colon Rectum 2003;46:1566-71

Fistulectome Device for core out fistulectomy Remove 2mm thickness of fistula tract Limited experience and results Dis Colon Rectum 2003;46:1566-71

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

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

4. Seton Loose Seton Cutting Seton Chemical Seton

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

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

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;77:898-901

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

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

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

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

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

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

Fibrin glue Results variable For complex fistula For simple fistula Successful rate ~50% Septic complication 3% Dis Colon Rectum 2005;48:2167-72 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;45:1608-15

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

Radiofrequency

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

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

Treatment of Anal fistula SUMMARY

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)

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)

Treatment for Anal fistula ~ End of presentation ~

Treatment of anal fistula Question and Answer

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

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

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

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;200:897-903