Small Intestine: Ostomy

Definitions

• Ostomy: Surgically Created Anastomosis of the GI Tract & Skin to Allow Fecal Diversion
• Stoma: Physical End of Bowel Protruding Through the Abdominal Wall

Descriptions

• Bowel Segment
  • Ileostomy: Segment of Ileum Used for Ostomy
    • Output Character: Higher with Liquid Contents
  • Colostomy: Segment of Colon Used for Ostomy
    • Output Character: Foul-Smelling Feculent Contents
• Bowel End
  • Loop-Ostomy: A Loop of Bowel Brought to the Skin with Two Openings (One Proximal & One Distal)
    • Defunctionalized Distal Limb: Proximal Functional Limb Everted to Occupy the Majority of the Aperture & Distal Limb Not Everted
    • Double Barrel: Both Limbs Everted to Occupy Similar Spaces
  • End-Ostomy: A Single End of Bowel is Brought to the Skin for Drainage
• Permanence
  • Permanent: No Plans for Later Takedown
    • Permanent Colostomy Preferred Over Permanent Ileostomy if Able (Lower Risk of Dehydration & Electrolyte Abnormalities)
  • Temporary/Diverting: Used to Allow Healing of Distal Site Due to High-Risk Anastomosis, Injury or Wound with Plans for Later Takedown
    • Temporary Loop-Ileostomy Preferred Over End-Ostomy if Able (Easier Future Takedown)

Site Selection

• General Site:
  • 4-5 cm Site
  • Just Inferolateral to the Umbilicus on Either Side
  • “Ostomy Triangle”:
    • Umbilicus
    • Pubic Tubercle
    • ASIS
  • Within Rectus Abdominis Muscle Preferred (Provides Support & Stability)
    • Possibly Elsewhere Dependent of Body Habitus – Obese Are Better Suited in the Upper Abdomen
• Considerations:
  • Patient Must Be Able to Visualize & Access the Stoma Easily
    • Obese Often Require Placement Higher Above the Umbilicus
  • Ostomy Site Must Be Flat to Avoid Interference of Appliance Adherence
    • Avoid Creases, Folds, Beltline, Previous Incisions, Umbilicus & Bony Prominences
  • Ensure ≥ 2 Inch Perimeter of Clear Intact Skin for Stoma Appliance Application

Procedure

• Mobilize the Bowel
  • Options to Gain Length:
    • Release Any Bowel Adhesions
    • Score Peritoneum of Mesentery (Pie-Crust)
    • Divide Mesentery/Blood Supply Proximally – First Ensure that there are Adequate Distal Arcades to Supply Blood for the Ostomy
    • Mobilize Peritoneal Attachments
    • Transect the IMA Proximal to the Left Colonic Artery Origin
• Create the Skin Opening at the Selected Site
• Consider Placing Prophylactic Mesh (Debated)
• Deliver Bowel Segment Through the Opening
• Close Remaining Abdominal Incisions
• “Mature” the Ostomy
  • End-Ostomy:
    • Open the Bowel
    • Place Four Stay-Sutures
    • Place Brooke Sutures Throughout to Evert
      • Ileostomy: 3 cm Proximal Seromuscular Bite
      • Colostomy: 1-2 cm Proximal Seromuscular Bite
  • Loop-Ostomy:
    • Consider Placing an Ostomy Bridge
    • Transect 80% of the Circumference of Bowel at Antimesenteric Side
    • Secure Limbs to the Abdominal Wall
      • Defunctionalized Distal Limb
        • Distal Limb Secured without Everting (Full-Thickness Bowel to Dermis)
        • Proximal Limb Secured & Everted (Brooke Sutures)
      • Double Barrel – Both Limbs Everted
• Place an Ostomy Appliance Over the Stoma

The Difficult Ostomy – Options if Difficult to Reach

• Always Mark Site Beforehand (Obese Require a More Cephalad Site)
• Fully Mobilize (Splenic Flexure, Lateral Attachments, Omental Attachments, Retroperitoneal Attachments)
• Vessel Division:
  • Divide IMA Close to its Base
  • Divide IMV Just Lateral to the Ligament of Treitz
• “Pie Crust” Mesentery – Creating Sequential “Windows” within the Mesentery
• Ensure Trephine/Opening is Large Enough
• Consider a “Loop-End” Ostomy if the End Will Still Not Reach – Closed Blind End is Just Under the Skin if a Point a Few cm More Proximal Has Better Reach
  • Also Known as an “End-Loop” or “Pseudo-Loop”
• Subcutaneous Lipectomy – Remove Subcutaneous Fat & Fix Skin to the Fascia

Ostomy Bridge (Stoma Rod)

• A Bar Placed Under a Loop-Ostomy to Stabilize at the Skin While Ostomy Granulates
• Removed After 3-5 Days
• Outcomes:
  • No Evidence of Reduced Risk of Stoma Retraction
  • Increased Risk of Local Complications (Edema, Skin Necrosis, Irritant Dermatitis, Peristomal Abscess & Bleeding)

Takedown/Reversal

• Minimum Time to Closure: 6-12 Weeks (12 Preferred)
  • Allows Resolution of Acute Inflammation & Dense Adhesions
• If Protecting a Distal Anastomosis: Obtain a Contrast Enema or Flexible Sigmoidoscopy Prior to Reversal to Ensure Anastomosis is Intact
• Technique
  • End-Ostomy Will Require Bowel Anastomosis to Reestablish Continuity
  • Loop Ostomy is Done through a Peristomal Circumferential Incision & Closed Transversely
  • Use Sharp Dissection & Avoid Serosal Tears from Blunt Dissection