Sutures, commonly known as stitches, are medical devices used to hold body tissues together after an injury or surgical incision. The goal is to support the wound until natural healing provides sufficient strength. The interrupted suture is a fundamental and frequently employed method for closing wounds, distinguished by securing each stitch as a separate, independent unit.
Mechanics of Interrupted Suturing
The interrupted suturing process involves placing a series of individual stitches along the length of the incision. The surgeon uses a needle holder to drive the curved needle through the tissue layers, emerging on the opposite side of the wound. Forceps stabilize the wound edges for precise needle passage, ensuring the edges are aligned horizontally and vertically.
Once the suture material passes through the tissue, a surgical knot is tied to secure the stitch. This knot must hold the tissue edges together without being overtightened, which could impair blood flow. After the knot is finalized, the remaining thread is cut, and the process is repeated for the next stitch. Each stitch is completely separate, requiring a fresh pass of the needle and a new knot.
Structural Security and Tension Control
The primary functional advantage of the interrupted technique stems directly from the independence of each stitch. This design allows for superior control over the tensile load across the wound. Since each knot is tied individually, the surgeon can fine-tune the amount of tension applied at specific points along the incision, which is particularly beneficial in areas under mechanical stress. This precision helps ensure that the wound edges are approximated—brought together—without causing excessive pressure that could compromise circulation.
This localized security is a major factor in preventing a catastrophic failure of the wound closure. If one knot loosens, breaks, or needs to be removed due to localized infection, the adjacent, independent stitches will maintain the integrity of the rest of the closure. The load is distributed across multiple anchor points, reducing the risk of complete wound dehiscence, which is the separation of the wound edges. Furthermore, the separation of the stitches allows for fine adjustments to be made to ensure perfect alignment, or apposition, of irregular wound edges.
Interrupted Versus Continuous Sutures
The interrupted technique is often contrasted with the continuous, or running, suture technique, which uses a single strand of suture material to close the entire length of the wound. In a continuous closure, the thread is secured only at the beginning and the end of the incision. The main benefit of the continuous method is speed, as it requires significantly less time to place and tie knots.
However, this speed comes at the expense of localized security. If a continuous suture breaks at any point along the line, the entire closure can unravel, leading to a complete failure of the wound approximation. Interrupted sutures are frequently chosen for wounds under high tension or in areas where a high degree of security is necessary, such as deep tissue layers. Conversely, the continuous technique is preferred for closing long, linear wounds or internal layers where tension is low and speed is a priority.