Parastomal hernia

• Incisional hernia related to an abdominal wall ostomy site
• Incidence
  • 5-10% of colostomies
  • 3-10% of ileostomies
  • ≈10-20% require repair

Classification

• Devlin Classification
  • Subcutaneous - hernia sac lies in subcutaneous plane
  • Interstitial - hernia sac lies within the layers of the abdominal wall
  • Intrastomal - sac penetrates the spout of an ileostomy
  • Peristomal prolapse - where the sac is within a prolapsing stoma
•  European Hernia Society (EHS) classification

Etiology

• Only true risk factor is BMI > 30
  • Risk factor most supported by evidence
• Patient specific
  • Age
  • Wound infection
  • Chronic increased abdo pressure, COPD
  • Obesity, weight gain (or malnutrition)
  • Steroids/immunosuppression
  • Malignancy
  • IBD
• Technical Factors
  • Emergency stoma
  • Surgical technique
  • Abdominal wall strength

Clinical

• Generally asymptomatic
• May present with difficulty placing stoma appliance
• Pain – usually mind
• +/- obstructive Sx

Management

• Indications for repair:
  • Difficulty with stoma appliance – unable to see or fit
  • Recurrent obstruction
  • Skin breakdown
  • Strangulation
  • +/- cosmetic
• Options:
  • Rejoin
  • Resite
  • Repair

Overview

• Primary vs. Mesh
  • Primary
    • Technically simple
    • Avoids manipulation of intra-abdo contents
    • Has low morbidity
    • BUT has high recurrence rate
    • Significantly higher than mesh repair (OR 8.9)
  • Mesh
    • Complications rare but difficult to manage, include
      • Contamination
      • Erosion
      • Fistula formation
    • Usually preferred technique, may be some instances where primary repair is better
• Open vs Lap
  • Not enough data to go other way
  • May have presumed lower morbidity and possibly improved outcomes
  • Best considered in patients without extensive intra-abdominal adhesions
  • Also better for smaller (%3C 8-12cm) hernias
• Onlay vs Sublay
  • Onlay
    • Technically more straightforward
    • Avoids intra-abdo dissection
    • Higher risk wound infection
  • Sublay
    • Increased intra-abdo dissection
    • Increases risk for adhesions and intestinal obstruction
    • Associated with fewer recurrences
    • Intra-abdo pressure cannot dissociate mesh from the repair

Techniques

Primary Repair

• Reduce the size of the facial defect by re-approximating the fascial edges with permanent sutures
• Approach generally avoided because of the physics of parastomal hernia and nature of the defect
• Unavoidable to cause tension on the repair
• Leads to high recurrence rates

Onlay Mesh Repair

• Incision made well away from stoma (typically in the midline)
• Subcutaneous dissection along rectus and oblique fascia
• Circumferentially around stoma
• Hernia reduced
• Abdo wall closed using tension free mesh repair
• Note risk ischaemic injury to the skin

Sublay Mesh Repair

• Less infection risk
• Entails large dissection

Intra-abdominal Mesh Repair

• Reduce hernia contents and close facial defect with mesh under the defect, and wide overlap

Sugarbaker

Keyhole

Parastomal Hernia-Contemporary Management, page 1 Parastomal Hernia Repair, page 1 Pauli, page 1

Prognosis / Natural Hx:

• Most hernias develop within first few years of stoma formation
• Mesh repair may lead to strictures (1/36 pts)