I'm always amazed when a patient walks into the emergency department 48 hours after an injury requesting sutures. What has this individual been doing for the past two days that prevented them from seeking treatment within a more traditional time frame? While this doesn't happen often, these cases always leave me wondering- is the wound still safe to suture? When does the wound repair window officially close?
The first thing to consider in evaluating a laceration is the ultimate goal of wound repair. What benefit do you hope to accomplish by choosing to close a wound vs. leaving it open? The goals of laceration repair are to "achieve hemostasis, avoid infection, restore function to the involved tissues, and achieve optimal cosmetic results with minimal scarring". You must consider these aspects first and foremost in your decision to close or not to close a wound.
The second step in evaluating the time frame for wound closure is to decide if the laceration should be closed at all based on its appearance. "Primary closure" refers to wounds that are sutured to close the defect. "Secondary closure" refers to wounds that heal on their own without having the edges approximated. Grossly contaminated wounds, animal bites, and deep puncture wounds carry a high risk of infection and may do best irrigated, cleaned, and left to heal secondarily. Cuts that are generally clean and do not contain a retained foreign body (or are at low risk for foreign body) can likely be closed without complication. Don't forget to take other factors that can lead to developing infection such as diabetes or an immunocompromised state into account in your decision.
If you determine that a laceration is a good candidate for primary closure, then consider the time that has passed since the injury. The thinking about what constitutes a safe wound closure window has changed over time. A so called "golden period" for laceration closure, 6 hours or less, was originally designated based on research done in the 1970's. This study found that wounds closed within three to five hours were less likely to become infected. As researched has progressed in recent years, this "golden period" has steadily become longer.
Studies now demonstrate that wound location affects the propensity for infection and therefore the window within which a wound may be closed. Wounds of the face and head, for example, have significantly lower rates of infection than other parts of the body. Therefore they may be closed at almost any time, even 24 to 48 hours after onset. Wounds of the legs and feet carry a higher risk of infection. Nonetheless, studies show they may safely be closed up to 19 hours post-injury.
The bottomline? The theory of a wound closure "golden period" has essentially gone out the window. There's no strict timeline delineating when a wound may or may not be primarily closed. Wounds that are prone to infection get infected. Wounds that are clean, and in a location where infection is unlikely don't. The age of the wound has less to do with the rate of infection than these other factors. So, the next time a patient presents to you with an unsightly scalp laceration that's 16 hours old, it's probably time to get out the stapler.