Can below-knee (BK) amputations be closed primarily or do they require delayed closure?

From the Guidelines

Below the knee amputations can be closed immediately in most cases, but the decision to close immediately or delay closure depends on several clinical factors, including the presence of infection, contamination, tissue damage, and vascularity, with the goal of minimizing morbidity, mortality, and improving quality of life. The decision between immediate or delayed closure is critical in determining the outcome of the patient. According to the 2024 ACC/AHA/AACVPR/APMA/ABC/SCAI/SVM/SVN/SVS/SIR/VESS guideline for the management of lower extremity peripheral artery disease 1, concurrent amputation with revascularization can be clinically appropriate in certain cases, and the amputation site may be left open for a delayed closure at a later time. This approach allows for surveillance of tissue viability over the days after revascularization and can be beneficial in patients with poor premorbid functional status, frailty, or severe comorbidity profile.

Some key factors to consider when deciding between immediate and delayed closure include:

• The presence of infection or significant contamination, which may require delayed closure to allow for debridement and improvement of the wound environment
• The adequacy of soft tissue coverage over the bone end, which is essential for primary closure
• The vascularity of the tissue, which can impact the healing process
• The patient's overall clinical situation, including their premorbid functional status, frailty, and comorbidity profile.

In cases where delayed closure is necessary, the wound is initially left open, debrided as needed, and closed later (usually within 5-7 days) once the wound environment improves 1. The use of negative pressure wound therapy (NPWT) can also be effective in achieving wound healing after revascularization and minor amputation when primary or delayed secondary closure is not feasible. Ultimately, the decision between immediate or delayed closure should be made on a case-by-case basis, taking into account the individual patient's clinical situation and the goal of creating a functional, well-healed residual limb while minimizing complications.

From the Research

Below Knee Amputations Closure

• Below knee amputations can be closed immediately or left open and closed later, depending on the patient's condition and the surgeon's preference 2.
• A study published in 2020 found that primary closure of below knee amputations can be safely performed in patients undergoing lower limb amputations following trauma, provided that a good lavage and wound debridement is performed 2.
• However, another study published in 2023 found that a novel strategy employing staged operative debridement for source control, negative pressure wound therapy, and reformalization can improve the rate of below knee amputation salvage and postoperative ambulatory status 3.
• The use of negative pressure wound therapy (NPWT) as a postoperative dressing can also help to condition the open stump for successful closure 4.
• In some cases, below knee amputation stumps that fail to heal can be revised using local debridement with gentamicin collagen, which can offer a viable alternative to conversion to above knee amputation 5.

Factors Affecting Closure

• The presence of chronic venous insufficiency or other comorbidities can affect the healing process of below knee amputations 4.
• The use of NPWT and other wound care strategies can help to promote healing and reduce the risk of complications 4, 3.
• The timing of closure, whether immediate or delayed, can also impact the outcome of below knee amputations 2, 3.

Complications and Outcomes

• Complications such as surgical site infections (SSIs) and dehiscence can occur after below knee amputations, regardless of whether the wound is closed immediately or left open and closed later 2, 6.
• The use of a novel strategy employing staged operative debridement for source control, negative pressure wound therapy, and reformalization can improve the rate of below knee amputation salvage and postoperative ambulatory status 3.
• The overall outcome of below knee amputations can be affected by various factors, including the patient's condition, the surgeon's experience, and the use of wound care strategies 4, 2, 3, 5.