A New Flap Design: Neural-Island Flap

Abstract

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 a...

Reconstruction of the Anterior Surface of the Ear Using a Postauricular Pull-Through Neurovascular Island Flap

“…20 Therefore, neurocutaneous island flaps were designed. 21,22 It is well known that sensibility of the neurovascular flaps increases the flap viability 23,24 ; however, we believe that it also facilitates its manual cleansing because it increases the sensitivity of the external ear canal.…”

A pedicled muscle flap based solely on a neural pedicle

“…The survival rate of the delayed neural-island flaps was found to be 94.5%, depicting a greater survival rate than an acutely-elevated neural-island flap (38%). 3 Ozkan et al harvested the biceps femoris muscle and musculocutaneous flaps based on their motor nerves. Average muscle viability levels of neuromuscular, neuromusculocutaneous, delayed neuromuscular, delayed neuromusculocutaneous, conventional muscle, and musculocutaneous flaps were 20.6 6 7.58, 22.4 6 4.21, 86.4 6 6.14, 85 6 4.21, 89.6 6 4.48, and 88 6 5.51%, respectively.…”

“…After neural-island flap description, the intrinsic vascularity of the nerve attracted our attention. 3 When a nerve is elevated for transposition, it is stripped of its extrinsic blood supply and must survive on its intrinsic blood flow. Previous investigations have tried to determine the maximum length of nerve that can be elevated before becoming ischemic.…”

“…2 On the basis of this work, Akyurek et al introduced the neural island flap, which is supplied solely by blood from the intrinsic vascular plexus of a cutaneous nerve. 3 These studies demonstrated that properly designed skin islands can be transferred based on the intrinsic vascularity of a peripheral nerve.…”

Selective Percutaneous Desiccation of the Perforators with Radiofrequency for Strategic Transfer of Angiosomes in a Sequential Four-Territory Cutaneous Island Flap Model

“…7,[17][18][19][20][21] Some novel applications of the delay process are more pertinent to tissue transfer in the setting of venous, neural, and prefabricated flaps. 20,[22][23][24] Thus, investigators continuously seek alternative pharmacologic, biochemical, or less invasive surgical strategies with which to manipulate and transfer vascular territories in an easy, reliable, and more innocuous manner. 8,11,12,14,15,[25][26][27][28][29][30][31][32][33] Nevertheless, questions constantly arise as to the interpretation of these experimentally encouraging methods in the clinical setting, and surgical delay is the only clinically established method for augmenting flap survival.…”