Video 5-23. Vertical mattress tip stitch
This technique, also described as the modified corner stitch, is designed to bring three ends of tissue together, and is used in the context of a flap, where it permits the tip of tissue to be inset. This can be conceptualized as a vertical mattress variation of the tip stitch, permitting circumferential tissue advancement while concomitantly encouraging wound eversion and mitigating the risk that the tip is set deeper than the surrounding wound edges. Since it is used only when attempting to approximate three segments of skin, this 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 6-0 suture is appropriate. On the trunk, extremities and scalp, a 3-0 or 4-0 suture material may be used. Monofilament nonabsorbable suture material is generally 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 needle is inserted through the epidermis at 90 degrees starting at the far right edge of the distal nonflap section of skin, with a trajectory running toward the tip. This entry point through the epidermis should be approximately 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 exit in the mid-dermis on the same portion of nonflap skin. Bite size is dependent on needle size.
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 place a suture through the dermis 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, at the same depth as it exited from the nonflap edge, and the needle is passed through the dermis on the flap tip at a uniform depth following a trajectory tracing an imaginary circle around the point where all three segments of skin will meet. The needle is then grasped with surgical forceps and released from the needle driver.
Attention is then shifted to the proximal nonflap edge of skin, where the needle is inserted in the mid-dermis of the incised edge, with the needle exiting through the epidermis ...