With all techniques, it is best to use the thinnest suture possible in order to minimize the risk of track marks and foreign-body reactions. On the face and eyelids a 6-0 or 7-0 monofilament suture may be used, though fast-absorbing gut may be used on the eyelids and ears to obviate the need for suture removal. Since the goal of the running diagonal mattress suture placement is primarily to encourage wound-edge eversion, fine-gauge suture material may be used on the extremities as well.
The needle is inserted perpendicular to the epidermis, approximately one-half the radius of the needle distant to the wound edge. This will allow the needle to exit the wound on the contralateral side at an equal distance from the wound edge by simply following the curvature of the needle.
With a fluid motion of the wrist, the needle is rotated through the dermis, taking the bite wider at the deep margin than at the surface, and the needle tip exits the skin on the contralateral side.
The needle body is grasped with surgical forceps in the left hand, with care being taken to avoid grasping the needle tip, which can be easily dulled by repetitive friction against the surgical forceps. It is gently grasped and pulled upward with the surgical forceps as the body of the needle is released from the needle driver. Alternatively, the needle may be released from the needle driver and the needle driver itself may be used to grasp the needle from the contralateral side of the wound to complete its rotation through its arc, obviating the need for surgical forceps.
The suture material is then tied off gently, with care being taken to minimize tension across the epidermis and avoid overly constricting the wound edges. The trailing end of suture is then trimmed.
Starting proximal relative to the surgeon, the needle is then reinserted perpendicular to the epidermis, approximately one-half the radius of the needle distant to the wound edge. The trajectory of the needle, however, is designed to be on a 45-60—degree angle relative to the incision line, pointed away from the starting apex.
With a fluid motion of the wrist, the needle is rotated through the dermis, and the needle tip exits the skin on the contralateral side, further along the incision line than its entry point.
The needle body is grasped with surgical forceps in the left hand as the body of the needle is released from the needle driver.
The needle is then reloaded in a backhand fashion and inserted at 90 degrees perpendicular to the epidermis just proximal (relative to the surgeon) to its exit point on the same side of the incision line as the exit point. The trajectory of the needle, however, is designed to be on a 45-60—degree angle relative to the incision line, pointed away from the starting apex.
The needle is rotated through its arc, exiting on the contralateral side of the wound (relative to the surgeon) further along the incision line.
Moving proximally relative to the surgeon, steps (5) through (9) are then sequentially repeated, until the end of the wound is reached. At that point, a loop is left in the penultimate throw and the suture material is then tied off gently, with care being taken to minimize tension across the epidermis and avoid overly constricting the wound edges (Figures 5-15A, 5-15B, 5-15C, 5-15D, 5-15E, 5-15F).