Flap |
Pedicle or free flap, antegrade or reverse pedicle |
Tissue |
Innervated cutaneous flap, frequently from a non.hair-bearing area; also may be de-epithelialized if a subcutaneous fascial flap |
Course of the vessels |
In a fascial plane, deep along the humerus; perforators enter the flap via a delicate septum from the undersurface |
Dimensions |
Up to 15 × 8 cm (primary closure only possible for flaps ≤ 6 × 12 cm) |
Extensions and combinations |
Can be harvested as an osteocutaneous flap with a segment from the humerus; can include a fasciocutaneous forearm extension |
Anatomy |
|
Neurovascular pedicle |
– |
Artery |
Posterior radial collateral artery (branch of the profunda brachii artery); distal flow from a recurrent radial collateral artery from the articular network around the elbow |
Veins |
Two concomitant veins and cephalic system |
Length and arc of rotation |
≤ 8 cm |
Diameter |
Arteries, 1.5–2 mm; veins, 2–2.5 mm |
Nerve |
Posterior cutaneous forearm nerve from the radial nerve |
Surgical technique |
|
Preoperative examinations and markings |
Doppler identification of vessel course recommended; mark the insertion of the deltoid muscle and the lateral condyle; outline the flap dimensions centered over this line |
Patient position |
Supine; arm draped to allow for free movement; arm on an arm table or fixed across the chest; tourniquet recommended (but sometimes hard to hold in place) |
Dissection |
Free flap and antegrade pedicle flap: start with a posterior incision down to the muscle fascia; raise the flap subfascially and tack the fascia to the skin to prevent shearing; continue to the anterior border of the triceps muscle, where the fascia dives deep and inserts into the humerus; perforators are seen in the septum; incise anteriorly down to the fascia; subfascial dissection should include the fascia of the flexor muscles; pursue the fascia down to the humerus; ligate the distal continuation of the posterior radial collateral artery; separate the fascial septum as close as possible to the periosteum; follow the pedicle proximally under the triceps muscle into the spiral groove; separate the lower cutaneous nerve from the radial nerve
Reverse pedicle flap: proceed with dissection as described for the free flap dissection; ligate the proximal inflow; pursue the distal pedicle toward the elbow
Fasciocutaneous forearm extension: extend the flap 5 cm distal to the elbow, with width that is similar to the lateral arm flap; raise the extension subfascially; include the recurrent pedicle as long as possible |
Advantages |
|
Dissection |
Flap dissection is rapid for experienced surgeons; a simultaneous twoteam approach is possible |
Vascular pedicle |
Reliable and constant pedicle with moderate diameter |
Flap size and shape |
Thin flap that can be made in various shapes; oval is the optimal shape |
Combinations |
Very versatile due to optional combinations with bone, tendon strip from the triceps, forearm fascia extension, and/or nerve for both innervation and vascularized flow through the nerve graft |
Disadvantages |
|
Flap |
Depending on the patient, the flap can be bulky due to the subcutaneous layer |
Donor site morbidity |
Scar is conspicuous; only donor sites ≤ 6 cm wide can be closed primarily, or else skin graft is required; no functional loss except numbness on the lateral forearm |
Pedicle |
Pedicle is short; vascular diameter can be small, especially in women |
Pearls and pitfalls |
|
Dissection |
Do not confuse the nerve branches; stay extremely close to the periosteum of the humerus to preserve the delicate septum; tack the fascia to the skin to prevent shearing forces; repair the tendon donor site in the triceps muscle |
Extensions and combinations |
Try to center a perforator over the strip of periosteum taken with the bony segment; the posterior cutaneous nerve can be harvested as a vascularized nerve graft |
Contouring and correction |
Flap tends to sag; contour corrections are frequently needed |
Clinical applications |
Defects of the dorsum of the hand and the first web space; defects around the elbow and the shoulder region when used as a distal or proximal pedicle flap |
