Keloid is benign fibrous growths that usually occur in chest wall, shoulder, back and mandible. It may be induced by acne, foliculitis, insect bites or other skin injuries such as surgery, lacerations and abrasion [1]. Keloid is often difficult to treat. The reported therapy methods include excision, irradiation, steroid injection, and pressure therapy with silicone gel sheets or bandages [2,3]. Surgical methods especially wound closure methods are very important in recurrence prevention. Many suture methods were reported in literatures Cosmetic result is another issue to be considered in keloid treatment [4]. Cosmetic outcome is as important as recurrence prevention. Based on the principle of recurrence prevention and cosmetic consideration, we used double layer continuous itradermal suture besides basic surgery techniques in keloid operation and compared it with interrupted suture and one layer continuous intradermal suture. This study has been approved by the ethical review board of Peking Union Medical College Hospital. Informed consent has been signed by all the patients before operation.

Patient groups

One hundred and thirty-three patients with chest keloids were treated with in our department from 2006 to 2011. The patients were divided into three groups randomly based on the month at which the operation was carried out. Patients whose operations were carried out in January, April, July and October were the double layer continuous intradermal suture group. Patients whose operations were carried out in Februaury, May, August and September were the conventional interrupted epidermal suture. Patients whose operations were carried out in other months were the one layer continuous intradermal suture. There were fifty four patients in the double layer continuous intradermal suture group. The average age of these is 24.6 years old. All of the keloids were in the front chest wall. The average size of the keloid was 4.2 cm×2.8 cm. Five of the keloids occurred after local operation. Twenty eight were after folliculitis. No specific reason could be traced out in other patients. Fifteen of the patients received steroid injection but failed. No previous treatment was used in other patients. There were forty one patients in interrupted epidermal suture group. The average age of these is 21.3 years old. All of the keloids were in the front chest wall. The average size of the keloid was 3.8 cm×2.4 cm. Three of the keloids occurred after local operation. Twenty six were after folliculitis. No specific reason could be traced out in other patients. Nine of the patients received steroid injection but failed. No previous treatment was used in other patients. There were thirty eight patients in one layer continuous intradermal suture group. The average age of these patients was 25.3 years old. All of the keloids were in the front chest wall. The average size of the keloid was 5.1 cm×2.6 cm. Three of the keloids occurred after local operation. Twenty three were after folliculitis. No specific reason could be traced out in other patients. Eight of the patients received steroid injection but failed. No previous treatment was used in other patients. The follow-up time was from 9 to 26 months. The recurrence rate and cosmetic satisfactory rate was recorded and compared.

Surgical technique

The edge of the keloid was marked with gentian violet. 0.5% lidocaine was used for local infiltration anesthesia in skin around the keloid. A full-thickness incision was made along the mark and the keloid was removed. After hemostasia, skin 3-5cm around the incision border was undermined at the deep layer of superficial fascia. As for wound closing and tension releasing, one layer of superficial fascia stitches was put with normal silk thread. This layer of stitch was fixation suture. The thread should tolerate skin tension and keep the superficial fascia part contact. In order to maintain the fixed wound elevated, we usually put the stitch at the superficial fascia layer 1-2 cm away from the wound edge (Figure 1). More suture stitches would increase foreign body reaction and scar formation. We avoid this side effect by using few stitches with best tension releasing effect. After the wound being fixed and the tension being released, the first layer of continuous intradermal suture was put. 3-0 monofilament nylon thread was used. The suture began from one end of the wound, extended at the deep side of skin dermis, ended on the other end of the wound (Figure 2). Each end of the thread was fixed on the skin with a piece of silcone tube. The deep side of skin dermis was approximated after this procedure. But the superfacial side of the dermis and the epidermis usually remained little apart from one another. Another layer of suture was need. This layer of continuous intradermal suture was put on the superfacial side of the skin dermis, just under the layer of epidermis (Figure 3). 3-0 monofilament nylon thread was used in this layer. The suture also began from one end of the wound, ended on the other end of the wound and each end was fixed on the skin with a piece of silcone tube. The epidermis was then well approximated. The wound was then fixed with strips and covered with sterile gauze. Radiation therapy was taken one and seven days after operation. Sutures can be removed easily 14 to 21 days after operation.

Figure 1: Superficial fascia fixation suture. Tension is released with this layer of sutures.

Figure 2: First layer continuous intradermal suture. Suture extands in the deep side of dermis. The deep part of the dermis was approximated after this procedure.

Figure 3: Second layer continuous intradermal suture. Suture extands in the superfacial side of the dermis.The dermis and epidermis was then well approximated.

Deep layer fixation method was the same in interrupted suture and one layer continuous intradermal suture method surgery. After the wound being fixed and the tension being released, the wound would be closed with interrupted suture or one layer continuous intradermal suture. The patients received the same auxiliary treatment.

Radiotherapy methods

Radiotherapy was applied at the operation sites on the first and seventh postoperative day. Every operation site received 900 cGy electron beam irradiation each time [3].

Evaluation after therapy

The scar at the operation site was evaluated during the follow-up period. The scar was rated using the following guidelines: Ordinary scar: The scar is flat, pale in color, and it is in the range of the operation incision; the patient may experience an occasional tickle at the site of the scar. Recurred keloid scar: The scar is protuberant, red or purplish red in color, and it exceeds the range of the operation incision; the patient often experiences serious itching and aching. The keloid therapy results were graded as follows: cured, an ordinary scar at the operation site; recurrence, a keloid scar in a part or the entirety of the operation site.

The patients’ aesthetic satisfaction was also recorded and evaluated. The aesthetic results were graded as good, acceptable, or poor.

Data analysis methods

Data was analyzed with SPSS17.0 software. Recurrence and satisfactory rate were compared with Chi-square test between double layer and interrupted suture, double layer and one layer suture.

Two recurrences were observed during follow-up time in patients treated with double layer continuous intradermal suture. The recurrence rate was 3.70%. Recurrence rate was 12.19% (5/41) and 7.89% (3/38) in patients treated with interrupted and one layer continuous intradermal suture. Satisfactory cosmetic rates (graded as good and acceptable) were 72.22% (37/54) in double layer continuous intradermal suture group, 29.27% (12/41) in interrupted suture group and 39.47% (15/38) in one layer continuous intradermal suture group. There were no differences in recurrence rate between double layer and interrupted suture (X²=2.46, P>0.05) or double layer and one layer suture (X²=0.16, P>0.05). There were differences in satisfactory cosmetic rates between double layer and interrupted suture (X²=9.30, P<0.01) or double layer and one layer suture (X²=9.05, P<0.01) (Figure 4). Obvious suture marks were observed in the patients treated with interrupted epidermal suture (Figure 5). Wider scars were observed in patients treated with interrupted epidermal suture and one layer continuous intradermal suture (Figure 6).

Figure 4: Chest keloid treated with double layer continuous intradermal suture. Before and twenty six months after operation. The scar was thin.

Figure 5: Chest keloid treated with interrupted suture. Before and twenty three months after operation. Suture mark was still obvious.

Figure 6: Chest keloid treated with one layer continuous intradermal suture. Before and eighteen months after operation. The scar was pale but wide.

Tension releasing is one of the important procedures in keloid recurrence prevention. To release natural skin tension after wound closure, many suture methods were recommended. Hyakusoku used three-layer suture in the subdermal, dermal, and epidermal layer [5]. They used skin adhesive and buried running sutures in epidermal layer closure to prevent suture marks after subdermal and dermal suture which keep the wound edge elevated. In Ogawa′s report, they emphasized the importance of subcutaneous/fascia tensile reduction suture [4]. They usually put some sutures in deep fascia layer. The superfacial fascia layer is also closed. These wound closure methods are effective and important in keloid recurrence prevention. But the importance of dermal layer closure is not emphasized.

Traditional closure methods of the dermis described in literatures are interrupted intradermal suture with interrupted epidermal suture or epidermal buried running suture [6]. Aim of such suture is wound approximation and tension reduction. The suture thread is usually left in skin tissue. Thread knots leaved in tissue can induce foreign body reaction and scar formation. Salamon et al observed the tissue reaction to suture thread histologically. They found that connective tissue capsule is formed around threads which are not absorbed. The histological reaction is the most intense around the traditional linen thread which leads to cicatrization [7]. Prolonged foreign body reaction can induce keloids and foreign body granuloma [8,9]. Absorbable suture are sometimes used in such circumstance, but the possibilities of wide scars or wound failure need to be considered. If the strength can not resist wound-shearing forces before the scar gain sufficient strength, wide scars or wound failure may occur as reported by Nordström [10].

Great care has been taken to prevent recurrence in keloid treatment in our department. Many methods and principles were considered in surgical procedure and postoperative treatment. These include wound tension reduction, postoperative radiation, micro-trauma surgical procedure, less postoperative inflammation reaction. Design of double layer continuous intradermal suture is based on these principles. Besides superficial fascia tension reduction suture, wound tension was further reduced by the deep layer continuous intradermal suture. On the other hand, this layer of suture can be removed easily 14-21 days after operation. No suture thread is left in the dermal layer later on. Foreign body reaction induced inflammation is then prevented. Combined with postoperative radiation, recurrence rate is great reduced.

Satisfactory cosmetic outcome is also reached with this design. With the superfacial layer continuous intradermal suture, the wound edge is well approximated. Healing process of the epidermis was enhanced. Suture mark was avoided and the scar is less obvious after operation than in traditional suture methods.

In conclusion, dermal and epidermal layers of the wound are all well approximated after the keloid being removed when it is closed with double layer continuous intradermal suture. Good treatment and more satisfactory cosmetic results are reached.