Step-off correction suture
Video 5-02. Depth-correcting simple interrupted suture
This technique is used to correct depth disparities when the depth of the epidermis on each side of an incised wound edge is significantly different. This problem usually stems from inaccurate placement of deeper sutures, though it may also occur as the result of differential dermal thicknesses in certain anatomic locations, such as the boundary of the lateral nose and medial cheek.
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. Since this technique is used to fine-tune epidermal depth and is therefore not designed to hold a significant amount of tension, a 6-0 monofilament suture is often appropriate. In areas under greater tension, such as the trunk and extremities, a 5-0 monofilament suture material may be used as well.
The needle is inserted perpendicular to the epidermis, approximately one-half the radius of the needle distant to the wound edge.
If the side of the wound where the needle is first inserted is higher than the contralateral side, a shallow bite is taken, with the needle skimming the dermal-epidermal junction and exiting in the center of the wound. If the side where the needle first enters is lower than the contralateral side, a deep bite is taken, with the needle exiting through the deep dermis or into the undersurface of the dermis, depending on the degree of desired correction.
The needle body is grasped with surgical forceps in the left hand and pulled medially with the surgical forceps as the body of the needle is released from the needle driver.
The needle is reloaded on the needle driver, and the contralateral wound edge is gently reflected back with the forceps.
If the second side of the wound is deeper than the first, then depending on the required degree of depth correction, the needle is inserted either through the underside of the dermis or laterally through the deep dermis on the contralateral side of the wound. If the second side is higher than the first, a superficial bite is taken, through the dermal-epidermal junction if needed, to permit correction.
The needle is rotated and exits through the epidermis, equidistant from the incised wound edge relative to the first bite.
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 5-2A, 5-2B, 5-2C, 5-2D, 5-2E).
Overview of the depth-correcting simple interrupted suture technique.