Anal stricture: narrowing of the anal canal due to contraction of the epithelial lining that has been replaced by fibrous connective tissue.
Aetiology
• Congenital o Imperforate anus • Acquired o Deep fissure o Inflammation of the anus: Crohn’s disease, ulcerative colitis o Trauma o Iatrogenic: haemorrhoidectomy, operations for imperforate anus, fissures, Delorme’s, colo/ileoanal anastomosis. o Neoplasia: anal margin or anal canal (SCC, adenocarcinoma, melanoma)
Clinical presentation
• Pain and strain at defaecation→ fear of defaecation • ↓ stool calibre • Constipation • Tenesmus • Possible haemorrhoids and fissures causing bright red PR bleeding • Incontinence, overflow diarrhoea • PR: tight anus
Management
• Anal stretch (Lord’s procedure) no longer used as ↑ risk of sphincter disruption. • Need to define cause for stenosis • Exclude malignancy • Investigations o EUA +/- biopsy any lesions o Colonoscopy to exclude synchronous lesions o Endoanal ultrasound: define sphincter complex o Manometry: resting/squeezing pressures • Conservative o High fibre diet o ↑ fluid intake o Bulk laxatives o Enemas o Gentle self-digital dilatation o Gentle dilatation with anal dilators (Hegar’s) • Surgery o Aim of anoplasty is to ↑ patency and maintain continence o The principle of anoplasty involves increasing the dimensions of the anal outlet by internal sphincterotomy and removal of cutaneous scarring and maintaining correction by proximal advancement of mucosa. o Release of scar tissue +/- flaps +/- grafts - Transverse closure - Simple random flaps (Y-V, mucosal advancement, S and C rotational flaps) -Full thickness advancement flap: diamond island advancement flap o Refer to colorectal surgeons