Delayed Primary Closure
Delayed primary closure of contaminated wounds was utilized frequently during World War I, well before the discovery of antibiotics (SDC-276). Despite the benefit of this technique in war wounds, it was not used frequently in civilian practice (SDC-277) and not evaluated in controlled studies. In 1963, the first randomized study reported that primary closure of potentially contaminated abdominal wounds had a 42% incidence of infection whereas delayed primary closure was associated with only an 8% incidence (SDC-278). In an observational study, delayed primary wound closure was used in 146 patients matched to 146 similar patients undergoing standard wound closure during the same period (SDC-279). Wound infection was significantly lower in patients with delayed primary closure (2.1% vs 23.3%). In 1973, 300 highly contaminated cases had no invasive infections using delayed primary closure (SDC-280). The technique was felt to be particularly applicable to clean contaminated wounds in patients over the age of 60 or who had associated diabetes mellitus, malnutrition, or obesity (SDC-281). Not surprisingly, a strong indication for delayed primary closure was in wounds involving the intestine (SDC-282-283). The most recent (2009) prospectively randomized study of 81 patients with dirty abdominal incisions showed that SSI developed in 42.5% of incisions closed primarily compared to 2.7% for delayed primary closure. In the same article, the authors reviewed 16 previously published studies comparing primary closure with delayed primary closure. A significant benefit was found in all studies except for those associated with appendicitis, typhoid ileal perforation, and ileostomy closure. Dirty abdominal wounds benefited the most. However, two meta-analyses concerning primary versus delayed primary closure showed no benefit for delayed primary closure in the treatment of appendicitis (SDC-284-285). There was also no advantage of delayed closure in patients with open fractures (SDC-286).
The benefit of delayed primary closure is related to improved blood flow at the wound edges, which develops increasingly over the first few days (SDC-287) and is associated with progressive increases in resistance to infections. In a classic experiment published in 1933 (SDC-288), a culture of S. aureus was applied at different intervals to surgical wounds in guinea pigs. When applied within 6 hours of closure, 100% of wounds became infected; when applied 24 hours after closure, 66% became infected; when 48 hours after closure, 56% became infected; 4 days after closure 10% were infected and 5 to 7 days after closure, none became infected. More recent studies have shown that to cause an infection in a closed wound, it requires about a 10-fold increase in the size of bacterial inocula every day that passes up to 6 days (SDC-289). Still another study in guinea pigs confirmed the increasing resistance to infection of contaminated wounds over a 7 day period (SDC-290).
Modifications of the concept of delayed primary closure have recently gained some favor. As an example, closure of the wound in obese patients using wicks between the sutures in 384 morbidly obese patients was associated with an infection rate of only 0.78% (SDC-291). As another extension of this concept, negative pressure wound therapy has been used as a bridge to close contaminated wounds (SDC-292). Vacuum-assisted closure has also been used for the treatment of open abdominal wounds to assist in fascial closure (SDC-293-295) and in large open wounds because there are several advantages including the removal of exudate and acceleration of the development of granulation tissue.
The potential benefit of delayed primary closure in highly contaminated wounds is well established and is related to improved delivery of functional phagocytes to the wound site, increasingly through the first 5 to 6 days.
Annals of Surgery. 2011;253(6):1082-1093. © 2011 Lippincott Williams & Wilkins
Cite this: Updated Recommendations for Control of Surgical Site Infections - Medscape - Jun 01, 2011.