This technique was developed to solve a problem encountered with standard tip stitch techniques—the tendency of the flap tip to sit deep relative to the surrounding skin. Some of this problem may be due to lack of attention to the importance of uniform depth when taking bites through the dermis on all sides, though more likely it is related to the relative upward pull on the nontip sections of skin by the transepidermal sutures in the standard tip stitch.
The vertical mattress variation of the tip stitch therefore allows better wound eversion and less of a tendency toward a depressed tip than the standard approach.
The tip stitch is very useful when bringing the tip of a flap into place. Importantly, this technique is designed to gently approximate the tissues so that the flap is properly inset in the surrounding skin. While it bears a technical resemblance to the buried purse-string approach, it is important to appreciate that the tip stitch is not designed to work under significant tension, as tension across the suture may lead to necrosis of the delicate and lightly vascularized tip of the flap.
This is particularly important here, since the vertical mattress tip stitch places two loops of suture material through the tip, increasing the risk of necrosis and tissue strangulation.
Placing set-back dermal sutures, imbrication sutures, or suspension sutures prior to placement of the tip stitch will ensure that the tip itself is not under tension when it is approximated with the surrounding skin.
Yet another variation of this technique entails burying the bite through the second nonflap wound edge so that the only percutaneous sutures are in the first nonflap edge of skin. In this case, steps (5) and (6) are replaced by taking a bite through the dermis alone before beginning the return course of the suture. This approach may slightly lessen the chance of infection and residual dimpling since the suture material on that edge does not traverse the epidermis. This half-buried approach is similar to the Allgöwer variation of the vertical mattress suture.