Surgical Technique

A simple technique for the retention of a subcuticular suture

D. Singh-Ranger
Northwick Park & St. Marks Hospitals, Watford Road, London HA1 3UJ U.K.

Correspondence to: D. Singh-Ranger, The Academic Department of Surgery, University College Hospital, 67-73 Riding House Street London, W1P 7LD, U.K.

Introduction Technique

Results Discussion References

Keywords: Subcuticular suture, retention knot, absorbable suture Surg J R Coll Surg Edinb Irel., 1 June 2003 149-151

The retention of a subcuticular stitch using absorbable suture has been performed using a variety of methods. These techniques may be difficult to master by surgeons new to the skill and have been associated with problems such as “dog ears” and a bulky knot that becomes difficult to bury. The latter can also be responsible for wound gapping especially of small wounds. The procedure described here provides a secure mechanism for retaining the subcuticular suture with minimal bulk to the knot. It is easy to master, does not produce wound gaping and is suitable for all wound sizes

INTRODUCTION
The technique of performing a retention knot for subcuticular suture can be difficult to master by those who are new to the procedure. The retention knot can cause other potential problems that include increased tissue reaction, gapping at the proximal and distal ends of the wound (caused by the sheer volume of the knot) and the creation of “dog ears” due to the asymmetry produced by suturing the wound edges. ^1-3 The latter may be a result of poor technique as well as failure to commence the suture in a symmetric manner. This can be a consequence of the position of the primary retention knot.

Retention knots may also be bulky and can be complicated by an irritative granulomatous reaction with ulceration through the skin.⁴ The knot may also be a possible nidus for infection and can lead to delayed wound healing. ^5,6

Following the procedure for subcuticular skin closure, the wound edges may gape if the suture is not secured properly and a stitch abscess can occur as a result of suture extrusion.⁷ Some of the techniques that are practised include the fashioning of a knot outside the skin or cutting the suture “long” and fastening it to the skin with adhesive tape (personal observation). ^8,9 However, problems with these methods are that both may be responsible for wound separation and act as a risk zone for bacterial infection.6 As a result, other mechanisms of creating a subcuticular knot and securing closure at the end of the procedure have been described in the literature.^{2, 5-11}  These methods appear complicated and difficult to master for the inexperienced trainee.

With these inherent difficulties in mind, this article describes a simple technique for retaining a subcuticular stitch for a wound of any size.

TECHNIQUE
The success of this technique relies on the fact that the incised skin can be seen to consist of two layers: the epidermis and the dermis (Figure 1). The knot is formed in the latter as it is thick and strong enough to retain the knot. The performance of the method requires that the incised wound be categorised into proximal (closest to the surgeon) and distal ends.

At the proximal end of the wound, approximately one centimetre away, the epidermal layer is entered with the suture needle and the tip is removed from the dermis (Figure 1a). In forming the initial knot, a loop of suture needs to be created and this is accomplished by passing the tip of the needle through thedermis perpendicular to the initial exit point (Figure 1b). The knot is formed by passing the whole suture needle through the loop in a direction that is towards the distal end of the wound. Tightening of the knot is achieved by holding the distal end of the suture (located outside the wound 1cm away from the proximal wound edge) and pulling the needle (Figure 1c). This prevents slippage of the knot and allows it to be buried within the dermis.

The wound edges are united in the conventional manner. Closure of the wound is concluded as depicted in Figure 2; at the distal end of the wound, the suture thread (attached to the base of the needle) is used as a retractor and the needle is passed through the hole in the skin, through which it has just exited, to emerge out of the skin perpendicular to the last exit site. The technique is repeated at this exit point in the same manner as described, the needle again being at a different angle to the second exit point. Both proximal and distal ends of the suture are cut in close approximation to the skin surface producing a symmetrically closed wound with no “dog ears”, bulky knot or gaping wound edges.

RESULTS
The technique described has been applied to a diverse range of surgical procedures with varying wound lengths (Table 1). The wound lengths varied from 0.5 to 30cm. Each wound was successfully closed using suture material ranging from 2/0 to 5/0 with either an attached straight or curved sharp/blunt needle. The united wound edges did not gape and adhesive skin tape was not required. An excellent cosmetic result (no “dog ears”) was obtained in every closure.

DISCUSSION
This method for creating a starting knot for subcuticular suture is easy to master and can be used by all grades of surgeons in all specialties, in particular minimally invasive and paediatric surgeons who wish to close small skin wounds. Subcuticular suture for small wounds has been shown to be associated with less pain and suggested as the preferred modality of closure. ¹²

The subcuticular suture technique detailed here is secure, in that it keeps the wound edges together, and minimizes the use of additional methods to close the skin. The knot is not bulky and the stitch can be performed with all types of needle; curved or straight and blunt or sharp.

In this report the knot has been fashioned using braided absorbable suture (Polygalactin) of sizes ranging form 2/0 to 5/0. The ability of successfully performing the retention knot with monofilament absorbable suture is currently the subject of an experimental trial. In particular, the degree of knot slippage and wound gapping following closure with such suture material is being studied.

REFERENCES
1. Van Rijssel EJ, Brand R, Admiraal C, Smit I, Trimbos JB. Tissue reaction and surgical knots. Obstet Gynecol 1989; 74: 64-68
2. Smoot EC. Method for securing a subcuticular suture with minimal buried knot. Plast Reconstr Surg 1998; 102: 2447-49
3. Moy RL, Lee A, Zalka A. Commonly used suturing techniques in skin surgery. Am Fam Physician 1991; 44: 1625-34
4. Aitken RJ, Anderson EDC, Goldstraw S, Chetty U. Subcuticular skin closure following minor breast biopsy: Prolene is superior to Polydioxanone (PDS). J R Coll Surg Edinb 1989; 34: 128-29
5. La Padula A. A new technique to secure an entirely buried subcuticular suture. Plast Reconstr Surg 1995; 95: 423-24
6. Giddins GE. Experience with knot-free absorbable subcuticular suture. Ann R Coll Surg Engl 1994; 76: 405-06
7. Du Bois JJ. A Technique for subcutaneous knot inversion following running subcuticular closures. Mil Med 1992; 157: 255
8. Ranaboldo C. Simplified method of subcuticular skin closure. Br J Surg 1992; 79: 1288
9. Hasson HM. Half-hitch knot for securing the end of continuous sutures. Obstet Gynecol 1992; 80: 724-26
10. Wong NL. The running locked intradermal suture: A cosmetically elegant continuous suture for wounds under light tension. J Dermatol Surg Oncol 1993;19: 30
11. Ftaiha Z, Snow SN. The buried running dermal subcutaneous suture technique. J Dermatol Surg Oncol 1989; 15: 264-66
12. Rosen DM, Carlton MA. Skin closure at laparoscopy. J Am Assoc Gynecol Laparosc 1997; 4: 347-51

Copyright: 4 April 2003