What is the likelihood of a suture coming loose if a surgeon's knot is not secure?

From the Guidelines

The likelihood of a suture coming loose if a surgeon's knot is not secure is high, and it is crucial to ensure a secure knot to prevent wound complications and promote optimal healing outcomes. A loose surgeon's knot can lead to wound dehiscence, infection, delayed healing, and poor cosmetic outcomes. The surgeon's knot is designed to maintain tension until the second throw is placed, and when this knot is not adequately tightened, the suture material can slip, creating gaps in the wound edges.

Key Considerations

• Different suture materials have varying degrees of knot security, with monofilament sutures like nylon or polypropylene being particularly prone to loosening if not properly secured 1.
• Braided materials like silk or polyester provide better knot security even with suboptimal technique.
• Proper knot tying technique involves maintaining appropriate tension throughout the tying process, ensuring that each throw is firmly seated against the tissue, and using the correct number of throws based on the suture material.
• The 'small bite' technique, which consists of a tissue stitch of approximately 5 mm from the median wound edges and a distance of approximately 5 mm from the other stitch, has been shown to have positive effects on wound healing and reducing the risk of incisional hernia 1.

Recommendations

• It is essential to use a secure surgeon's knot and proper knot tying technique to prevent suture loosening and promote optimal wound healing.
• The use of a high suture length-to-wound length ratio, such as 4:1 or more, can also reduce the risk of incisional hernia and wound complications 1.
• The 'small bite' technique should be considered for midline emergency laparotomy, although further studies are needed to confirm its effectiveness in this setting 1.

From the Research

Suture-Related Complications

• The likelihood of a suture coming loose if a surgeon's knot is not secure is a significant concern in surgical procedures 2, 3.
• Studies have shown that suture-related complications, such as wound dehiscence and wound site infection, can occur even with secure knots 2, 4.
• The use of barbed sutures has been proposed as a solution to reduce suture-related complications, as they do not require knots and can facilitate quicker wound closure 3, 4.

Barbed Sutures

• Barbed sutures have been shown to be safe, convenient, and effective in various surgical procedures, including body-contouring and total knee arthroplasty 2, 4.
• However, the use of barbed sutures has also been associated with increased superficial infection rates and shorter estimated closure times 4.
• The development of antimicrobial sutures, including those coated with antiseptics, has been proposed as a solution to minimize the occurrence of surgical site infections 5.

Wound Closure Outcomes

• A study on the use of barbed delayed absorbable polydioxanone sutures after emergency laparotomy found that 40% of patients developed surgical site infections, and 5.7% experienced burst abdomen 6.
• However, the study also found that barbed delayed absorbable sutures allowed for faster wound closure without the need for an assistant, and had satisfactory outcomes in terms of reducing suture-related complications 6.