The 'parachute' bolster technique for securing intraoral skin grafts.

Abstract

Successful skin grafting of intraoral defects can be challenging. The tie-over bolster method is the most popular technique in use today. We describe an alternate method of securing intraoral skin grafts--the "parachute" bolster technique--and we present a case report.

Introduction

Skin-graft healing follows a progressive course, and several conditions are necessary for graft survival: (1) adequate vascularity of the recipient bed, (2) graft immobilization, and (3) adherence of the graft to the defect. [1] These conditions must be met if the graft is to successfully progress through the stages of plasma imbibition and revascularization. Plasma imbibition is the passive exchange of nutrients across a diffusion gradient. [2] This phase begins immediately after the placement of the graft, and it continues until blood flow is established approximately 48 hours later. During this process, a fibrin network develops that holds the graft in place. [3]

During the first 48 hours after graft placement, vascular buds in the recipient bed merge with the disrupted vascular ends of the graft and establish blood flow. True circulation usually develops between postoperative days 4 and 7, and the revascularization stage is then complete. [3]

Graft failures can be caused by the shearing forces of mobile grafts and by the separation of the graft from its recipient bed by substances such as air, blood, saliva, fat, and sera. [1] Failures can be prevented by immobilizing the graft and closing up any potential dead spaces that might lead to separation.

When grafts are placed on surfaces that are inherently immobile, stable, and well vascularized, bolstering with a stent might not be required. When bolsters are used, the pressure they exert should be uniform. Pressures should be greater than interstitial pressures (15 to 20 mm Hg) to prevent seroma formation, but less than capillary pressures (25 to 30 mm Hg) to permit perfusion. [4] Proper bolster selection and placement is, therefore, important for graft survival. A variety of stent materials is available, including antibiotic-impregnated gauze, cotton balls, resin molds, and foam pads. [5]

With the common tie-over bolster technique described by Schramm and Myers in 1980, stent material is secured by the placement of interrupted sutures along the edges of the defect. [6] When this approach is used in the oral cavity, skin graft survival might not be as predictable as it is for grafts placed on external surfaces. The tissue elasticity of intraoral structures and their continual movement as a result of talking, chewing, salivating, and swallowing can displace a stent and compromise the immobilization and protection of the skin graft.

In this article, we propose an alternate technique for immobilizing intraoral grafts that might be more effective than the tie-over technique, especially for the grafting of defects of the buccal mucosa.

Graft placement technique

The skin graft is positioned intraorally in the recipient bed and secured to the defect's edges with 4-0 chromic sutures (figure 1). The graft is "pie-crusted" to allow for the outflow of any intervening sera or blood. After antibiotic ointment is applied to the area, a single layer of nonadherent petroleum gauze and an antibiotic-impregnated gauze stent are placed over the graft. A long Keith needle is used to pass a 4-0 nylon suture through the stent, the graft, and the skin of the oral defect. A small segment of a red rubber catheter is cut, and the suture is removed from the needle and passed through this rubber shod. Then the suture is reattached to the needle and passed back through the graft and stent. These parachute sutures are tied intraorally over the bolster to secure the stent. As an alternative, the Keith needle can be first placed through the skin surface and then passed intraorally and back again to tie over the rubber shod externally.

Case report

A white, 70-year-old woman with a history of a T4N0 squamous cell carcinoma of the left mandibular alveolar ridge was treated primarily with a left hemimandibulectomy, a partial glossectomy, a left selective neck dissection (levels I through IV), and reconstruction with a radial forearm free flap. Seven months after the patient completed a course of postoperative radiation therapy, she developed a recurrence in the buccal mucosa of her left oral commissure. The 1 x 2-cm lesion was treated with wide local excision (2-cm margins), which left a 3 x 4-cm through-and-through defect. The defect was repaired with an Estlander flap and split-thickness skin graft. The graft was secured with a parachute bolster (figure 2). Postoperatively, the patient had a 100% take of the graft and excellent oral competence, and she was pleased with the cosmetic result (figure 3). Nearly 4 years out from her surgery, she was disease-free and doing well.

Discussion

The parachute bolster technique is a simple and effective method of securing intraoral stents for skin grafts. This technique has been used for repairing several different oral defects, including those in the floor of the mouth, buccal mucosa, and lip (it was successfully used to reattach a large avulsed segment of lip in a patient who had been bitten by a dog).

The bolster should remain in place for 3 to 5 days to allow the graft to take. Once it does, the bolster can be easily removed. Removal of the rubber shod before postoperative day 6 is important to prevent scarring and dimpling of the skin. Patient tolerance of this technique is high, and no complications have been reported to date.

We believe that in properly selected cases, this method is potentially more effective than the tie-over technique for securing intraoral skin grafts. Further studies to compare the two techniques could confirm our supposition.

References

(1.) Hoffman HT, La Rouere M. A simple bolster technique for skin grafting. Laryngoscope 1989;99:558-9.

(2.) Ablove RH, Howell RM. The physiology and technique of skin grafting. Hand Clin 1997;13:163-73.

(3.) Smith JW, Aston SJ, eds. Grabb and Smith's Plastic Surgery. 4th ed. Boston: Little, Brown, 1991:28-9.

(4.) Weiner LJ, Moberg AW. An ideal stent for reliable and efficient skin graft application. Ann Plast Surg 1984;13:24-8.

(5.) Caldwell RK, Giles WC, Davis PT. Use of foam bolsters for securing facial skin grafts. Ear Nose Throat J 1998;77:490-2.

(6.) Schramm VL, Jr., Myers EN. Skin grafts in oral cavity reconstruction. Arch Otolaryngol 1980;106:528-32.