At operation wounds to be grafted are excised down to the underlying fascia and haemostasis is secured. A square piece of cork measuring 42x42 mm (1.65x1.65") with thickness 2.5 mm (0.1") is covered with a split skin autograft, dermal size down. Smaller graft remnants are also suitable by placing them on the cork plate like a ‘puzzle’. The cork, covered with graft, is then placed in a special MEEK cutting machine.

The machine contains 13 parallel circular blades. The cork plate with the graft on it is passed through the machine, where the rotating blades cut through the graft, but not through the cork. Thus the graft is cut into 14 stripes, 3 mm (0.12") wide. After the first pass, the cork is rotated 90° and passed through the machine once more, thus cutting the graft into 14x14 = 196 square pieces measuring 3x3 mm (0.12x0.12").

The upper (epidermal) surface of the graft is then sprayed with an adhesive dressing spray and allowed to dry and become tacky. The cork plate, covered with graft and adhesive is then pressed onto a prefolded polyamide gauze, which is folded on an aluminium foil backing into 14x14 square pleats, the size of which corresponds to the size of the cuts in the graft. Then the cork is gently removed, leaving the graft islands adhering to the gauze. The gauze is pulled out by firm traction on all four sides, until the pleats become completely unfolded. Finally the aluminium backing is peeled off, to leave the expanded gauze with the separated adherent autograft islands ready for transplantation.

After trimming the margins, or folding them double down, the gauze is applied, graft side down, to the wound bed and secured with surgical staples. After about 6 days the grafts have grown sufficiently into the wound bed to allow removal of the gauze, leaving the autograft islands in situ on the wound. The grafts are then covered with a non-adherent sheeting to prevent any movement during daily dressing changes. After a further 5-6 days the sheeting is removed. Daily dressings are continued until epithelialization is complete.

Only in cases of a large expansion factor (1:9), it is recommended to cover the MEEK grafts with an overlay of allografts, meshed 1:1.5 (a procedure called ‘sandwich grafting’). At lower expansions ratio, the use of allografts is not necessary. Alternatively cultured autologous keratinocytes can be applied to accelerate wound closure at large expansions.

Cutting machine: The cutting machine contains 13 circular blades mounted on a cutting axis. The cork plate with the graft is placed in a cutting block that moves under a bridge during cutting. Both the drive of the blades and the drive of the cutting block can be performed by pneumatic motor or by hand.

The motor drive of the blades is exchangeable with the hand drive and both can be supplied as separate sets. The drive of the cutting block is not exchangeable; it is either motor driven or hand driven. The hand drive of the cutting block can be provided with gearwheels for faster run of the block. For pneumatic drive a pressure of 5-7 bar (72-100 psi) is required.

The blades are coated with a durable, wear resistant ceramic layer. The cutting axis can simply be replaced. Individual blades can also be replaced. The machine is supplied with a single or a double cutting block. The double cutting block enables simultaneous cutting of two cork plates. Single and double blocks are exchangeable. The machine is entirely steam sterilized, except for the motor. A sterilization case is available.

Gauzes: The pre-folded MEEK gauze consists of an aluminium backing and a polyamide fabric, slightly adhering to each other. After expansion the aluminium foil is disposed of, while the fabric with the grafts is applied to the wound. Each gauze is supplied with a 42x42x2.5 mm (1.65x1.65x0.1") cork plate and sterile packed in a peel pouch. Standard packages are 10 and 40 pieces in a box. Available expansion ratios are 1:3, 1:4, 1:6 and 1:9.

Adhesive Dressing Spray: The adhesive is a spray bottle with a content of 200 ml (6.8 fl.oz).One bottle is enough to spray 200-250 gauzes.