This technique is designed to bring three ends of tissue together, and is often used in the context of a flap, where it permits the tip of tissue to be inset. The buried variation of the tip stitch can be conceptualized as a low-tension purse-string closure, since it utilizes a mild form of circumferential tissue advancement. Since it is used only when attempting to approximate three segments of skin, it is a niche technique.
Suture choice is dependent in large part on location, though as always the smallest gauge suture material appropriate for the anatomic location should be utilized. On the face, where this technique may be used for flap repairs, a 5-0 absorbable suture is appropriate. On the extremities and scalp, a 3-0 or 4-0 absorbable suture material may be used, and on the back and shoulders, 2-0 or 3-0 suture material is effective, though care should be taken with leaving the relatively thick 2-0 suture in the superficial dermis, as it may hydrolyze relatively slowly. Monofilament and braided suture materials may both be appropriate when utilizing this technique.
The flap is brought into place using buried sutures, allowing the tip to rest with only minimal tension in its desired position. The wound edge of the distal portion of nonflap skin is gently reflected back, permitting visualization of the dermis.
The needle is inserted into the underside of the dermis on the far right edge of the distal nonflap section of skin with a trajectory running parallel to an imaginary circle around the point where all three segments of skin will meet. Generally, this entry point in the dermis should be approximately 1-3 mm set-back from the epidermal edge, depending on the thickness of the dermis and the anticipated degree of tension across the tip. The needle, and therefore the suture, should pass through the deep dermis at a uniform depth. Bite size is dependent on needle size, though in order to minimize the risk of necrosis it may be prudent to restrict the size of each bite.
The needle is then grasped with the surgical pickups and simultaneously released by the hand holding the needle driver. As the needle is freed from the tissue with the pickups, the needle is grasped again by the needle driver in an appropriate position to repeat the preceding step on the flap tip to the left of the previously placed suture.
A small amount of suture material is pulled through and the needle is inserted into the dermis in the flap tip, and the same movement is repeated.
The same technique is then repeated on the proximal nonflap edge of skin, keeping the needle parallel to the imaginary circle and moving in the same counterclockwise direction. The needle then exits close to the original entry point on the right side of the wound.
The suture material is then gently pulled taut and tied utilizing an instrument tie, burying the knot (Figures 4-36A, 4-36B, 4-36C, 4-36D, 4-36E).