Reconstructive procedures after ablative head and neck cancer surgery often require the replacement of tissue by transplantation of microvascular anastomosed free flaps in order to compensate functionally and aesthetically for the defect. For soft tissue reconstruction of limited-size defects, the radial forearm free flap (RFFF) has become the most commonly used flap in the head and neck region. This thin and versatile flap is also used widely for thin defects of the oral cavity, with good functional and cosmetic results. The high calibre of the vessels and the long vascular pedicle considerably facilitate anastomoses and make the RFFF a reliable flap with a high success rate.

The harvesting of a defined amount of tissue for the reconstruction of remote defects inevitably leads to a removal defect at the donor site, which is potentially accompanied by corresponding morbidity. Prolonged wound healing, for example, is an undesirable inconvenience that may lead to poor aesthetic results, and flexor tendon exposure may lead to an appreciable loss of function. Since the introduction of the RFFF more than 30 years ago, different approaches have been made to reduce donor site morbidity. These range from changes in the design of the flap, for example the suprafascial dissection, to different closure techniques. Oversewing with the flexor muscles has been recommended to protect the flexor carpi radialis tendon, and the approximation of the flexor digitorum muscle to the flexor and abductor pollicis longus muscle has been described to provide a well-vascularized bed for a split-thickness skin graft. The split-thickness skin graft requires a further donor site and is prone to inconvenient prolonged wound healing. In order to avoid its use, different methods of primary closure have been reported: the V–Y transposition of an ulnar forearm fasciocutaneous flap, a transposition flap, the prefabrication of the forearm fascia, and the use of tissue expanders.

For indirect defect closure, autogenous full-thickness skin grafts (FTSG) have been reported to achieve similar or better aesthetic results. These can be gained locally or harvested from remote regions such as the inner upper arm, abdominal wall, or groin.

For the sake of completeness, allogeneic grafts and vacuum-assisted closure (sub-atmospheric pressure dressing) should also be mentioned here, however these have taken a back seat in the face of the good results obtained and feasibility of the previously described procedures.

In head and neck microvascular reconstruction, a long pedicle and a thin flap are often needed, which commonly leads to the removal of the RFFF from the very distal forearm. The resulting donor site defect is close to the hand wrist, requiring special consideration with regard to wound closure due to the superficial flexor tendons and the restricted amount and moveability of the local tissue.

Surgical technique

All flaps were raised as a fasciocutaneous RFFF, without the use of a tourniquet. For aesthetic reasons, no flap was extended to the dorsal aspect of the arm. The superficial branch of the radial nerve was identified over the paratenon of the brachioradialis muscle and was carefully preserved during further dissection in all cases to prevent paresthesia of the back of the hand between the thumb and index finger. No coverage of the flexor tendons by oversewing muscle bellies of the flexor muscles was performed. The radial artery was not reconstructed in any patient.

A wavelike skin incision for exposure of the proximal vascular pedicle was used in all cases as a prerequisite for the introduced technique ( Fig. 1 ). Before making a skin incision, the dimension of the sinusoidal curve was planned in relation to the future donor site defect such that the length of the curve matched the oblique distance and its width matched half of the oblique distance of the defect. Two spindle-shaped FTSGs out of the convexity of the incision line were taken from the adjacent skin of the volar forearm (see Fig. 2 ). Prior to excision, the widths of the biconvex FTSGs were determined as half the width of the defect site. Temporary parallel mattress sutures for preserving the defect size were performed until the FTSGs were finally sutured in place. After a slight rotation from their original longitudinal orientation, the two spindle-shaped FTSGs were used to cover the donor site defect of the RFFF. This rotation to an oblique to perpendicular orientation of the FTSGs was performed to avoid parallel arrangement to the flexor tendons. No fenestrating incisions or cross-sutures for size reduction of the wound were performed. To prevent formation of seroma, a tie-over dressing was used for 10 days.

Plotting of the planned incisions on the left forearm (hand wrist to the left, elbow to the right). The continuous lines represent the outline of the radial forearm free flap (6 cm × 5 cm), as well as the wavelike access incision to the pedicle. The dashed lines predict two biconvex full-thickness skin grafts and their oblique orientation for prospective wound coverage.

The completely raised radial forearm free flap (pedicle still perfused) is positioned on the bend of the elbow. The two spindle-shaped full-thickness skin grafts appear semi-lunar due to the loss of tissue interconnection and skin curling.

In all cases the donor site of the local FTSG was closed primarily in the context of the closure of the access incision (see Fig. 3 ). To accomplish this, gentle subcutaneous mobilization was performed. A passive silicone capillary drain was placed subfascially before closure. No vacuum-assisted closure (sub-atmospheric pressure dressing) or splint cast was used.

Interrupted 3–0 sutures are placed peripherally and in-between the transplanted full-thickness skin grafts. No fenestrating incisions, cross-sutures, or persistent subcutaneous sutures are performed. The forearm is closed primarily after subfascial insertion of a silicone capillary drain.