Cath Lab Digest

C hronic wounds are a significant problem worldwide, resulting in substantial morbidity and cost to healthcare systems. Chronic venous insufficiency affects approximately 5% of the adult population in developed countries, and the prevalence of chronic ulcerations is believed to be 1% in the world population.^1-3 Even in situations with "good wound care," typical patients with venous ulcers may require 12 to 24 weeks to heal.^3,4 In a study of 260 patients with venous ulcers treated with multilayer compression bandages, 32% did not achieve complete wound closure after 24 weeks of care and had a mean wound duration of 62.4 weeks.³

Using occlusive dressings to cover chronic wounds and maintaining a moist wound environment facilitate healing far better than the traditional approach of a simple covering material and medicated ointment. Different types of moisture-retentive dressings have been developed and can be grouped into several categories based upon their chemical properties.⁵ Gel-forming dressings such as calcium alginates, which absorb the wound exudate to form a non-adherent gel, have been shown to accelerate wound healing in a moist environment,⁶ facilitate debridement, and help prevent trauma to the wound bed and periwound skin. The use of calcium alginate dressings has been evaluated in many clinical situations, including split-thickness skin graft donor sites,^7-11 diabetic foot ulcers,^12-14 pressure ulcers,^15-17 and venous insufficiency ulcers.^18-20 Because alginate dressings show significant differences in important handling characteristics,²¹ the performance characteristics of various calcium alginate dressings provide additional information upon which to base treatment decisions.

Methods

The purpose of this open, randomized, controlled clinical study was to compare the performance characteristics and clinical effect of two calcium alginate dressings in the management of venous ulcers: 3M Tegagen™ HG (High Gelling) Alginate Dressing (3M Health Care, St. Paul, Minn.) - Alginate A - and Sorbsan™ Topical Wound Dressing (Dow Hickam Pharmaceuticals Inc., Sugar Land, Tex.) - Alginate B. The secondary dressing and compression therapy were the same for both treatment groups: 3M Tegasorb™ Hydrocolloid Dressing (3M Health Care, St. Paul, Minn.); Medicopaste® Bandage (Graham-Field, Bay City, NY); and 3M Coban™ Self-Adherent Wrap (3M Health Care, St. Paul, Minn.). Two clinical sites (University of California, San Francisco, and Minarets Medical Group, Inc., Fresno, Calif.) enrolled all eligible outpatients attending wound clinics and willing to participate in this study. All patient-related visits occurred between September 1997 and April 1999. Patients provided informed consent and were randomized to one of the treatment groups according to the protocol randomization schedule. Dressing changes, wound assessments, and dressing performance evaluations were completed weekly. Patients were followed for a maximum of 6 weeks or until the venous ulcer no longer required the use of a calcium alginate dressing.

Inclusion criteria. To participate in this study, patients had to be greater than or equal to 21 years of age, able to understand and undergo the product application and assessment procedures required, and willing to sign an informed consent form before enrollment. The patient had to have a venous insufficiency ulcer of at least 1 month's duration, with an area ranging from 3.0 cm² to 100 cm², and with a moderate (3 cc to 5 cc) to large (>5 cc) amount of exudate.