A new flap design: neural-island flap

This report introduces the "neural-island flap" concept, which represents a consistent and reliable skin flap design supplied only by the intrinsic vasculature of a cutaneous nerve. In this study, the lateral femoral cutaneous nerve was selected as the pedicle of the neural-island flap, and a standard skin flap, which is the territory of the accompanying vessels (i.e., iliac branches of the iliolumbar artery and vein), was elevated on the lower dorsal region of the rats. In a total of 92 Wistar rats, three experiments were performed. In part I (n = 24), the vascular anatomy of the lateral femoral cutaneous nerve was established by the methods of dissection, microangiography, nerve mapping, perfusion with colored latex and India ink, and histologic analysis. In part II (n = 46), the role of the cutaneous nerve in supporting an acutely elevated skin flap was explored by creating five flap groups as follows: group 1, conventional flap (artery, vein, and nerve intact); group 2, neural island flap (only the nerve intact); group 3, neurocutaneous flap (vein and nerve intact); group 4, denervated flap (artery and vein intact); and group 5, skin graft. In part III (n = 22), the role of a preliminary surgical delay procedure to augment the survival of the neural island flap was investigated. Results of the anatomic studies indicated a consistent perineural vasculature by the accompanying iliolumbar artery. Skin flaps survived totally in groups where the artery and vein were intact, whereas mean survival rates for the neural island flap and the neurocutaneous flap were 38.2 +/- 3.1 percent and 44.5 +/- 3.8 percent, respectively (p > 0.05). Results of part III of the experiment demonstrated a significantly higher survival for the delayed neural island flap (94.5 +/- 5.5 percent) compared with the acutely elevated neural island flap (p < 0.05). The perineural and intraneural vessels were found to be greatly dilated after a delay procedure, demonstrated by direct observation, microangiography, histologic analysis, dye injection study, and scanning electron microscopy. On the basis of this promising series of experiments, a clinical technique was developed using the sural neural-island flap. The flap was used to reconstruct lower extremity defects in four cases. A delay procedure was accomplished in the first stage by elevating a fasciocutaneous flap from the midcalf region based on a posterior skin bridge and the sural nerve. After a 2-week delay period, a sural neural-island flap was created based on the nerve and transposed to the defect. Flap survival was complete in all cases, with a satisfactory result. The authors conclude that this report proves for the first time that a robust and reliable skin flap can be created pedicled only by the intrinsic vasculature of a cutaneous nerve, after a proper surgical delay. The so-created neural-island flap design offers two novel advantages: (1) a very narrow pedicle and (2) a pedicle without any restriction to a specific pivot point, in addition to the previously described unique advantages of preservation of a major artery and avoidance of microvascular anastomoses.     

The medialis pedis flap: a new fasciocutaneous flap

An anatomic study (30 fresh specimens dissected) and clinical experience (5 patients) have shown the reliability of a fasciocutaneous flap raised from the medial side of the foot. The artery that supplies the flap is issued from the medial plantar artery. The arch of rotation allows one to cover some specific areas, such as the medial malleolus, posterior aspect of the heel, and distal insertion of Achilles tendon.     

The medial gastrocnemius muscle flap: a local free flap

A new application of the medial gastrocnemius muscle flap has been described. Lengthening of the sural vascular pedicle was obtained using interposition vein grafts. This allowed coverage of a larger defect than that which could have been obtained with the tethered muscle and without further insult to the already disturbed lower extremity anatomy. The principle of pedicle lengthening can be used to increase the arc of rotation of various other muscle, myocutaneous, skin, or bone flaps and thereby increase their usefulness.     

Free-flap free flap

We present a patient who sustained bilateral below-knee amputations that were treated with skin grafts as initial coverage. A latissimus dorsi free flap was later used as definitive coverage of one stump. Then at a subsequent operation a portion of the same latissimus dorsi free flap was reharvested, again as a free flap, and transplanted to cover the contralateral stump. Thus one latissimus dorsi free flap was used twice as a free flap (free-flap free flap) to cover bilateral amputation stumps in sequential operations.     

The forearm flap

We present our experimental and clinical experiences with the free neurovascular forearm flap. The flap is based on the radial artery, one of the great veins of the forearm (cephalic, basilic, or interconnecting vein), and one or two cutaneous forearm nerves (ulnar, median, or lateral). Because of the standard anatomy, the large caliber of blood vessels, the good sensory supply, the quality and quantity of the forearm skin, and the thin layer of subcutaneous fat, the free forearm flap is a technically easy and safe flap for reconstruction of soft-tissue defects, especially those in the head and neck and those areas of the extremities where sensitive skin is desired.