Chapter 5.12: The Cruciate Mattress Suture

Figure of 8 suture

This is an infrequently used technique that is a hybrid between a simple interrupted suture, a mattress suture, and a simple running suture. It is useful when the benefits of interrupted sutures—especially the frequent knot placement leading to a more secure closure—is desired. It may also be used if the wound length is slightly too long for a single simple interrupted suture. This approach entails taking two simple interrupted bites in succession and then tying off the suture, leaving an “x” of suture material over the wound edge. It may be used alone in the context of small wounds under minimal to no tension, such as those formed by a punch biopsy or a traumatic laceration. It may also be 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. This technique may also be used for vessel ligation and hemostasis, where it is classically referred to as the figure of 8 suture.

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. This technique is rarely used on the face, but if it is used there a 6-0 or 7-0 monofilament suture may be used for epidermal approximation. On the extremities, a 5-0 monofilament suture may be used if there is minimal tension, and 4-0 monofilament suture can be used in areas under moderate tension where the goal of suture placement is relieving tension or hemostasis as well as epidermal approximation. In select high-tension areas, 3-0 monofilament suture may be utilized as well. When used for hemostasis on the interior of a wound, a 4-0 absorbable suture may be used.

1. 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.

2. 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.

3. 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.

4. Starting proximally relative to the surgeon, steps (1) through (3) are then repeated.

5. The suture material is then tied off gently (Figures 5-12A, 5-12B, 5-12C, 5-12D, 5-12E).

This technique is useful when attempting to obtain hemostasis in a punch biopsy site or when some superficial oozing remains in a patient on aspirin or anticoagulant therapy. It can be conceptualized as a transepidermal figure of 8 suture, as it has the potential to loosely ligate small vessels in the dermis and subcutis. This approach is, interestingly, fairly popular in the veterinary literature.

As always, it is important to enter the epidermis at 90 degrees, allowing the needle to travel slightly laterally away from the wound edge before fully following the curvature of the needle when utilizing this technique. This will allow for maximal wound eversion and accurate wound-edge approximation.

Care should be taken to avoid skimming the needle superficially beneath the epidermis. This results from failing to enter the skin at a perpendicular angle and to follow the curvature of the needle. This may result in wound inversion as the tension vector of the shallow bite pulls the wound edges outward and down.

The larger amount of suture material traversing the skin in this technique translates into an increased risk of track marks over comparable techniques. Instead of the single section of suture material that traverses the skin with a simple interrupted suture, the cruciate mattress leaves an “x” of suture material taut against the skin; all of this material has the tendency to bury itself in the underlying epidermis during healing and this phenomenon may be exacerbated during the course of postoperative wound edema, leading to an increased risk of unsightly track marks if the suture material is not removed promptly.

As with any suturing technique, knowledge of the relevant anatomy is critical. When placing a cruciate mattress suture it is important to recall that the structures deep to the epidermis may be compromised by the passage of the needle and suture material. For example, the needle may pierce a vessel leading to increased bleeding.

While this may occasionally represent an advantage of this technique, particularly if the knot is tied relatively tightly, structures deep to the defect may be constricted. This can lead to necrosis due to vascular compromise or even, theoretically, superficial nerve damage.

The potential to constrict deeper structures may be used to the surgeon’s advantage in the event that a small vessel deep to the incision line is oozing; rather than opening the wound, localizing the source of the bleed, and tying off the individual vessel, it may be possible to simply place a cruciate mattress suture incorporating the culprit vessel within its arc, tie it tightly, and thus indirectly ligate the vessel. This should only be used in the event that the offending vessel is relatively small, since otherwise there is a significant risk that this indirect ligation will not be sufficiently resilient. Moreover, tying the suture too tightly may increase the risk of developing track marks or superficial necrosis.

This technique may elicit an increased risk of track marks, necrosis, and other complications when compared with techniques that do not entail suture material traversing the scar line, such as buried or subcuticular approaches. Therefore, sutures should be removed as early as possible to minimize these complications, and consideration should be given to adopting other closure techniques in the event that sutures will not be able to be removed in a timely fashion.