Clinical Review

How to avert postoperative wound complication—and treat it when it occurs

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Avoid wound infection and dehiscence with the help of thorough preoperative assessment, careful technique, tried-and-true strategies, and a few novel products


 

References

The authors report no financial relationships relevant to this article.

Despite advances in medicine and surgery over the past century, postoperative wound complication remains a serious challenge. When a complication occurs, it translates into prolonged hospitalization, lost time from work, and greater cost to the patient and the health-care system.

Prevention of wound complication begins well before surgery. Requirements include:

  • understanding of wound healing (see below) and the classification of wounds (TABLE 1)
  • thorough assessment of the patient for risk factors for impaired wound healing, such as diabetes or use of corticosteroid medication (TABLE 2)
  • antibiotic prophylaxis, if indicated (TABLE 3)
  • good surgical technique, gentle tissue handling, and meticulous hemostasis
  • placement of a drain, when appropriate
  • awareness of technology that can enhance healing
  • close monitoring in the postoperative period
  • intervention at the first hint of abnormality.

In this article, we describe predisposing factors and preventive techniques and measures, and outline the most common wound complications, from seroma to dehiscence, including effective management strategies.

Biologic phases of wound healing—overlapping and interdependent

It was pioneering Scottish surgeon John Hunter who noted that “injury alone has in all cases the tendency to produce the disposition and means of a cure.”15

Unlike the tissue regeneration that occurs primarily in lower animals, human wound healing is mediated by collagen deposition, or scarring, which provides structural support to the wound. This scarring process may itself cause a variety of clinical problems.

Wound healing is characterized by overlapping, largely interdependent phases, with no clear demarcation between them. Failure in one phase may have a negative impact on the overall outcome.

In general, wound healing involves two phases: inflammation and proliferation. Within these phases, the following processes occur: scar maturation, wound contraction, and epithelialization. These repair mechanisms are activated in response to tissue injury even when it is surgically induced.

Inflammatory phase

The initial response to tissue injury is inflammation, which is mediated by various amines, enzymes, and other substances. This inflammation can be further broken down into vascular and cellular responses.


Inflammation triggers increased blood flow and migration of neutrophils, monocytes, macrophages, and other cells into the wound.

The first burst of blood acts to cleanse the wound of foreign debris. It is followed by vasoconstriction, which is mediated by thromboxane 2, to decrease blood loss. Vasodilation then occurs once histamine and serotonin are released, permitting increased blood flow to the wound. The surge in blood flow accounts for the increased warmth and redness of the wound. Vasodilation also increases capillary permeability, allowing the migration of red blood cells, platelets, leukocytes, plasma, and other tissue fluids into the interstitium of the wound. This migration accounts for wound edema.

In the cellular response, which is facilitated by increased blood flow, cell migration occurs as part of an immune response. Neutrophils, the first cells to enter the wound, engage in phagocytosis of bacteria and debris. Subsequently, there is migration of monocytes, macrophages, and other cells. This nonspecific immune response is sustained by prostaglandins, aided by complement factors and cytokines. A specific immune response follows, aimed at destroying specific antigens, and involves both B- and T-lymphocytes.

Proliferative phase

Proliferation is characterized by the infiltration of endothelial cells and fibroblasts and subsequent collagen deposition along a previously formed fibrin network. This new, highly vascularized tissue assumes a granular appearance—hence, the term “granulation tissue.”

Collagen that is deposited in the wound undergoes maturation and remodeling, increasing the tensile strength of the wound. The process continues for months after the initial insult.

All wounds undergo some degree of contraction, but the process is more relevant in wounds that remain open or involve significant tissue loss.

Last, the external covering of the wound is restored by epithelialization.

TABLE 1

Classification of surgical wounds

CLASS I – Clean wounds (infection rate <5%)
  • Created under ideal operating room conditions
  • Usually an elective surgical incision made under aseptic conditions and not predisposed to infection
  • Uninfected wound with no inflammation
  • No entry into oropharyngeal cavity, respiratory tract, alimentary tract, or genitourinary tract
  • Always closed primarily and usually not drained
CLASS II – Clean–contaminated wounds (infection rate 2–10%)
  • Entry into oropharyngeal cavity, respiratory tract, alimentary tract, or genitourinary tract under controlled conditions without unusual contamination or significant spillage, e.g., hysterectomy, appendectomy
  • Minor break in surgical technique
  • No evidence of infection
CLASS III – Contaminated wounds (infection rate 15–20%)
  • Fresh, open, traumatic wound or injury, e.g., soft-tissue laceration, open fracture
  • Surgical procedures that involve gross spillage from gastrointestinal tract
  • Genitourinary or biliary tract procedures in the presence of infected urine or bile
  • Major break in surgical technique
  • Incisions that encounter acute, nonpurulent inflammation
CLASS IV – Dirty or infected wounds (infection rate >30%)
  • Traumatic wounds more than 4 hours old
  • Wounds that are heavily contaminated or clinically infected before surgery, e.g., tubo-ovarian abscess
  • Perforated viscera
  • Neglected traumatic wounds in which devitalized tissue or foreign material is retained
SOURCE: Centers for Disease Control and Prevention and the American College of Surgeons

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