From Stillwater-Ponca City (OK) Ostomy Outlook Nov 1998:

Facts About Convexity

This fact sheet is developed by the WOCN Clinical Practice Committee. Publications produced by the WOCN are reviewed for scientific accuracy, appropriateness of content and readability. This publication is not copyrighted and the WOCN encourages users of the fact sheet to duplicate as many copies of the fact sheets as desired.

Editor's note: WOCN provides two versions of this fact sheet: one intended for professionals and the other for patients. I've chosen to reproduce the professional version because it has more information, even though some of its language is a bit more technical.

DEFINITION: A pouching system designed to improve the peristomal seal by increasing the depth of the faceplate in order to conform to the peristomal skin contour.

INDICATIONS FOR USE

• Flush stoma
• Peristomal creases and wrinkles
• Retracted stoma
• Protruding/Flabby abdomen
• Stomal os at or near skin level
• Liquid drainage/high output stomal effluent (when associated with a flush or retracted stoma)
• Frequent pouching system changes caused by a flush or retracted stoma

CONTRAINDICATIONS

• Exercise caution when using convexity in the presence of:
  • Pyoderma Gangrenosum
  • Caput Medusa (peristomal varices)
  • Pressure Ulcers
  • Mucocutaneous separation
  • Crohn's ulceration
  • Malignant ulceration

PRODUCTS AND DEVICES FOR CONVEXITY

• Convex Insert: Pre-sized plastic rings for use in the flange of a 2 piece system
• Barrier Strips/Rings: A moldable product used to create convexity
• Pouch/Wafer with Pre-cut Convex Barrier: A skin barrier manufactured in a specific size with built-in convexity; available in 1 or 2 piece pouching systems
• Pouch/Wafer with Cut to Fit Convex Barrier: A skin barrier manufactured with built-in convexity that can be cut to a specific stoma size
• Custom Made Convex Product: A product with built-in convexity, manufactured for a specific patient
  NOTE: Ostomy belts and binders may be used to provide additional support.
  NOTE: There are differing degrees of depth available in convex products.

EXPECTED OUTCOMES

• The patient will attain or maintain:
  • Intact peristomal skin
  • Comfort and satisfaction with pouching system
  • Increased pouching system wear time
  • Cost effective stomal management

FACTORS TO CONSIDER

• Convex pouching systems should be fitted by WOC/ET Nurse and re-evaluated regularly
• Convex products may leave an imprint on the skin
• Convex barriers may be less flexible
• Some convex products may have a higher cost, but should be more cost effective due to less frequent need for pouch changes
• Patients are encouraged to contact WOC/ET Nurse if any of the following occurs:
  • Stomal changes: bumps, cuts, bruises or bleeding
  • Peristomal skin changes: irritations, rash, color changes, bleeding, pain, itching or lesions
  • Continued frequent leakage of pouching system

RESOURCES

1. Wound, Ostomy and Continence Nurses Society Clinical Practice Committee
2. Hampton, B. Ostomies and Continent Diversions: Nursing Management; St Louis: Mosby, 1992.
3. Turnbull RB, Weakley FL. (1967) Atlas of Intestinal Stomas, St. Louis, Mosby.
4. IAET (WOCN) Standards of Care: Patient with Colostomy
5. Rolstad, BS, Boarini JB.: Principles and Techniques in the use of convexity. Ostomy/Wound Management. 1996,42(1), pp.24-32.
6. Manufacturer's catalogs

To contact WOCN, phone 1-888-224-WOCN