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Understanding Complicated Surgical Wounds

Practice Accelerator
February 28, 2023


Surgical wounds originate when a surgeon cuts into tissue with a surgical tool, such as a scalpel.1 The size and placement of a surgical wound will depend entirely on the procedure performed due to varying incision requirements. Regardless, most surgical interventions aim for wound closure with primary repair. Tissue edges are typically brought together and held in place by various modalities, such as sutures or staples.2 However, this result isn’t always the case, as some wounds may be left open to heal secondarily or may fail to heal primarily.1 This piece will discuss the surgical wound timeline, various complications of a surgical wound, signs/symptoms of infection, along with the recovery process for patients. More specifically, the Centers for Disease Control and Prevention (CDC) outlines a classification that applies to surgical wounds to preemptively identify those that might be at risk for surgical site infection. This classification includes the following3:

  • Class I – clean, uninfected, primarily closed, and in lower-risk anatomic areas
  • Class II – clean-contaminated, without the appearance of infection, but possibly in a higher-risk anatomic area
  • Class III – contaminated, possibly when an object comes into contact with the wound that increases risk, such as with a gunshot wound
  • Class IV – dirty-contaminated or dirty-infected, have devitalized tissue, possibly exposed to things like fecal material

Surgical wounds

Much like other types of wounds, there is an anticipated timeline for surgical wound healing. Generally, a wound heals within 4 to 6 weeks.4 Some wounds can take longer, though, possibly up to a few months.1 However, clinicians can consider any surgical wound that deviates from this projected wound healing process complicated or even chronic.4 Simply, this delay in healing can continue to be a problem when a wound significantly interferes with the quality of one’s life or causes sequelae or further complications.

What Types of Complications Occur?

Surgical wound complications may take several forms. In general, wounds become complicated when they become infected, inflamed, when tissue edges separate, and/or fluid builds up under the surface (discussed in further detail below). If present, these conditions will delay the physiological healing process. Most complications, such as a surgical site infection (SSI), tend to occur within the first 30 days after surgery.1,5,6 Estimates cite that about 2-4% of all patients who have surgical procedures will have an SSI.5 This type of complication can not only cause mortality and morbidity but can also lead to hospital readmissions. 5 Therefore, prompt identification of early signs and symptoms of infection is critical.7Signs of SSI may include the following:

  • Erythema
  • Incision is hot to the touch
  • Delayed healing
  • Malodor
  • Purulent drainage
  • Localized pain
  • Fever

There are other more specific types of complications that can happen when it comes to surgical wounds, though, including the following:

  • Dehiscence is the partial or total separation of previously approximated wound edges, estimated to usually take place at 5-8 days post-op.8 Sutures placed too tightly may increase risk. Excessive drainage or bleeding can be early signs of dehiscence, whereas the most worrisome sequela is exposure of underlying tissues, organs, or bone.8
  • A fistula is an abnormal connection between the wound bed and a nearby organ structure or blood vessel. Cutaneous fistulae can be thought of as abnormal “tubes” connecting tubular structures (ie, intestine, artery, vein, etc) to the external skin. They often result originally from trauma and/or surgical procedures and are driven by lingering inflammation/infection. For example, an "enterocutaneous" fistula refers to a pathological tubular connection between an intestine and the skin.9
  • A seroma is a collection of serous fluid in the wound bed (thought to be due to poor lymphatic drainage and the presence of a physiological “dead space”). Seromas may present as swelling localized to the surgical site, fluctuant, and exhibiting clear drainage from the wound. Depending on severity, they may require aspiration or surgical revision to be drained. The presence of a seroma also increases the risk of infection.10
  • A hematoma is a collection of blood in the wound bed. Hematomas are more concerning than seromas because they may be caused by incomplete hemostasis and active bleeding, requiring urgent surgical revision. They may also require evacuation.

Which Patients Are Most at Risk for Surgical Wounds?

Certain patient demographics, comorbidities, and peri-procedural variables can place an individual patient at higher risk for postoperative wound complications. Some of these risk factors can be minimized or optimized, whereas others cannot. Patients with one or more of the following risk factors should be monitored closely after surgery for the development of complications11,12:

  • Elderly patients
  • Surgical procedure lasting more than 2 hours
  • Surgical drain removed too early in postoperative course
  • Oncology patients (history of radiation therapy and/or glucocorticoid use)13
  • Obesity
  • Uncontrolled diabetes (hyperglycemia leading to infection; poor tissue perfusion secondary to microvascular disease)
  • Smoking (vasoconstriction and immunosuppression)
  • Malnutrition/hypoalbuminemia (insufficient protein to support the proliferative stage of wound healing)
  • Ischemia (vascular disease, venous insufficiency, and/or “too tight” sutures)

General Management Principles to Prevent/Treat Surgical Wound Complications

At the time of discharge and transfer to post-acute care, it is critical to identify and document the location of all wounds. Clinicians should perform a thorough physical examination and communicate the results with the multidisciplinary team and patient to ensure they are aware of these wounds.14 In addition to examining wounds, the operating clinician should also remove nonabsorbable sutures and/or staples at an interval appropriate to the individual case. This process typically takes place around 7-21 days post-procedure, depending on location.15 If not removed, they can become a nidus for infection and prevent proper wound healing. Clinicians should consider these other general principles when discharging or transferring a patient:

  • Daily wound assessment, dressing changes, and local wound care is imperative.
  • If a clinician suspects infection, prompt microbiological swabs for culture can help to identify the causative organism and antibiotic sensitivities.7
  • Early (and frequent) mobilization appropriate to the case promotes lymphatic drainage. This mobilization can help prevent the accumulation of seromas and maximize outcomes.16,17


While the majority of postoperative wounds will heal within weeks, many can take longer. Surgical wound complications—such as infection, dehiscence, seroma, and fistula—most often occur within the first month after surgery. Optimizing modifiable risk factors, early mobilization, daily assessment, and regular wound care can minimize complications, much like in the care of other complex wounds.


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  2. Misteli H, Kalbermatten D, Settelen C. Simple and complicated surgical wounds. Ther Umsch. 2012;69(1):23-27.
  3. Surgical Site Infection Event (SSI). National Healthcare Safety Network. Published January 2023. Accessed February 7, 2023.
  4. Wallace HA, Basehore BM, Zito PM. Wound healing phases. In: StatPearls. StatPearls Publishing;2022.
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  11. Surgical Site Infections. Hopkins Medicine. Accessed on February 5, 2022.…
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  13. González CVS, de Carvalho VF, Park Kim SH, et al. Complicated surgical wounds and associated factors in oncology patients. Plastic and Aesthetic Nursing. 2020;40(2):91. doi:10.1097/PSN.0000000000000307
  14. Nagle SM, Stevens KA, Wilbraham SC. Wound assessment. In: StatPearls. StatPearls Publishing; 2022.
  15. Jewell T. Surgical staples: what you need to know. In: Healthline. Published January 11, 2019. Accessed February 6, 2023.…
  16. Tazreean R, Nelson G, Twomey R. Early mobilization in enhanced recovery after surgery pathways: current evidence and recent advancements. J Comp Eff Res. 2022;11(2):121-129.
  17. Shakil-Ur-Rehman S, Sheikh S, Danish K. The Role of Early Mobilization in the Prevention of Post Operative Wound Infection after Lower Extremity Orthopedic Surgeries. J Islam Int Med. 2012;7:63-66.

The views and opinions expressed in this blog are solely those of the author, and do not represent the views of WoundSource, HMP Global, its affiliates, or subsidiary companies.