Case 154: Pain in the perineum
A 33 year old man presents with 2 days of increasing pain adjacent to his anus. He has no other bowel symptoms and is otherwise well.
1. What does the photo show?
An acute perianal abscess has been drained and a seton inserted through a fistula.
2. How would you manage this man?
The primary therapy is examination under anaesthesia with incision and drainage of the abscess. The patient should be placed in lithotomy position. A digital rectal examination is performed to assess the extent of sepsis and its relation to the sphincters and levator ani. The internal opening of a fistula may be palpable.
Rigid sigmoidoscopy is then performed to look for proctitis. The perineum is then prepared and draped. Anoscopy using an appropriate retractor (eg. Park's, Hill-Ferguson) allows inspection for an internal fistula opening. The abscess is then drained with incision over the most fluctuant point and away from the anal verge. A small disc of skin is excised to maintain drainage and prevent early closure.
Probing is discouraged as may lead to iatrogenic fistula creation, however if an internal opening is identified then a seton should be inserted if possible to prevent early recurrence. A large cavity should be managed with insertion of a DePezzer catheter which is left for several weeks. Broad spectrum antibiotics with anaerobic cover may be indicated in diabetic patients and those with Crohn's disease.
Patients should be advised to maintain a good bowel habit with a diet high in fresh fruit and vegetables, adequate fluid intake and frequently fibre supplementation.
3. What would you discuss when consenting him for the procedure?
Informed consent requires discussion of the nature of the disease and it's natural history. The management options and potential benefits and limitations of each should be covered.
The specific issues for this man will be the risks of recurrence and fistula requiring seton insertion. He should be warned that he may have a drain tube or a seton left in situ and that he will require dressings and salt baths possibly for several weeks. Careful surgery should not endanger the sphincter mechanism however undrained sepsis may.