This is the standard benchmark suture used for closure and epidermal approximation. It may be used alone in the context of small wounds under minimal to no tension, such as those formed by either a small bunch biopsy or a traumatic laceration. It is also frequently used as a secondary layer to aid in the approximation of the epidermis when the dermis has been closed using a dermal or other deep suturing technique.
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. Suture choice will depend largely on anatomic location and the goal of suture placement. Simple interrupted sutures may be placed with the goal of: (1) accomplishing epidermal approximation in a wound under moderate tension, such as a laceration or punch biopsy, or (2) fine-tuning the epidermal approximation of a wound where the tension has already been shifted deep utilizing a deeper dermal or fascial suturing technique.
On the face and eyelids a 6-0 or 7-0 monofilament suture may be utilized for epidermal approximation. When the goal of simple interrupted suture placement is solely epidermal approximation, this suture material may be used on the extremities as well. Otherwise, 5-0 monofilament suture material can be used if there is minimal tension, and 4-0 monofilament suture may be used in areas under moderate tension where the goal of suture placement is relieving tension as well as epidermal approximation. In select high-tension areas, 3-0 monofilament suture may be utilized as well, particularly in the context of a multimodality approach, for example when mattress sutures are placed in the center of the wound to maximize tension relief and eversion, and simple interrupted sutures are placed at the lateral edges of the wound to minimize dog-ear formation.
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 (Figures 5-1A, 5-1B, 5-1C, 5-1D).