The lateral arm fascial free flap: its anatomy and use in reconstruction

Free fascial transfer has been used for reconstruction of gliding surfaces of the upper and lower extremities or when thin, pliable coverage is required (hand, heel, nose, and ear). In our experience with the lateral arm fasciocutaneous flap, we have found that the fascia alone is an excellent source of tissue for free flap transfer. A thorough investigation of the microscopic, gross, and radiographic anatomy of the lateral arm fascia was undertaken by the study of 25 fresh cadavers. Vascular pathways were mapped, their locations were analyzed, and then they were correlated with the elevation, design, and transfer of the flap. The lateral arm has a large fascial component located anterior and posterior to the lateral intermuscular septum, which itself lies between the triceps and the brachialis and brachioradialis muscles. It is perfused by the posterior radial collateral artery (PRCA), one of the terminal branches of the profunda brachii. This vessel (PRCA) provides at least four fascial branches from 1 to 15 cm proximal to the lateral epicondyle, the largest of which is located an average of 9.7 cm superior to the lateral epicondyle. Fascia up to 12 x 9 cm may be used with good axial perfusion. The histologic cross sections demonstrate the complex anatomy of the fascia itself, as well as its relation to the nutrient vessels. We have applied the lateral arm fascial flap in five cases of upper extremity reconstruction. We have also found this flap valuable in preservation of underlying anatomic detail for total reconstruction of the ear and nose when local tissue and more conventional flaps were not available.     

Reversed forearm island flap supplied by the septocutaneous perforator of the radial artery: anatomical basis and clinical applications

The cutaneous perforators of the radial artery adjacent to the superficial branch of the radial nerve and the lateral antebrachial cutaneous nerve were investigated, and the vascular anatomical features of the reversed forearm island flap supplied by those accompanying perforators were documented. Ten fresh cadavers were systemically injected with lead oxide, gelatin, and water. Twenty forearms were then dissected, and an overall map of the cutaneous vasculature and source vessels was constructed. The accompanying arteries were observed to lie along the lateral antebrachial cutaneous nerve and the superficial branch of the radial nerve and to nourish the skin through cutaneous branches. Vascular communication among these cutaneous vessels was evaluated, to determine the cutaneous vascular territory of the radial forearm flap. This anatomical information facilitates flap design in the forearm region. Clinical experience regarding the usefulness of the reversed forearm island flap for hand reconstruction for a series of five patients is presented.     

Upper limb salvage using a free radial forearm flap

Microsurgical transfer of a skin flap salvaged from a nonreplantable upper extremity that would otherwise be discarded may provide essential soft-tissue coverage of the amputation stump, so maintaining a functional range of motion in the elbow joint. A radial forearm free flap measuring 24 cm long by 9 cm wide was salvaged from the degloved forearm skin of a patient who sustained a proximal forearm amputation that was considered unsuitable for replantation. This allowed coverage of the proximal radius and ulna, preservation of a functional elbow joint, and successful fitting of a below-elbow prosthesis.     

Osteoradionecrosis of the olecranon: treatment by radial forearm flap

Osteoradionecrosis of the olecranon is an unusual pathologic entity, treated best by debridement and wound closure using vascularized tissue. Local skin is often unavailable for flap design and transposition. The radial forearm flap can be isolated on a proximal vascular pedicle and transposed to cover the wound. In the case presented, healing was brisk and complete, allowing early elbow mobilization. Although the donor site is not easily concealed, no functional impairment results from flap elevation and all full-thickness wounds are confined to the involved extremity.     

Anatomical consideration of reverse-flow island flap transfers from the midpalm for finger reconstruction.

Primary soft-tissue coverage for large palmar defects of the fingers is a difficult problem for cases in which homodigital or heterodigital flaps cannot be used. The aim of this study was to explore the vascular and neural anatomy of the midpalmar area to assess the possibility of reverse island flaps from this area. In 24 cadaver hands perfused with a silicone compound, the arterial pattern of the superficial palmar arch and common palmar digital artery was examined. The cutaneous perforating arteries and nerve branches supplying the midpalmar area were dissected, and the number, location, and arterial diameter of these branches were measured. In six other specimens, the common palmar digital artery was injected to determine the skin territory supplied by the artery. The superficial palmar arch contained the three common palmar digital arteries and its terminal branch coursed along the radial margin of the index metacarpus. This terminal branch had three to six cutaneous perforators (diameter range, 0.1 to 0.5 mm) and supplied the radial aspect of the midpalmar area located over the ulnar half of the adductor pollicis muscles. The midpalmar area was divided into two regions-the proximal and distal-according to the vascular distributions. The proximal region contained dense aponeurosis and thin subcutaneous tissue, and the cutaneous perforators were rather sparse (between three and nine) and had a small diameter (0.1 to 0.3 mm). The distal region, which had loose aponeurosis and abundant subcutaneous tissue, had a rich vascular supply from the common and proper digital artery. Perforating arteries of this region coursed frequently in an oblique fashion and the number of perforators (between eight and 15) and their arterial diameters (diameter range, 0.1 to 0.5 mm) were higher than those of the proximal region. The area of skin perfused by the common palmar digital artery was 5 x 3 cm at the distal midpalmar region. There were three to five cutaneous nerve branches from the palmar digital nerve supplying the midpalmar area. From this study, two different reverse flaps were proposed. First, a 5 x 2 cm flap from the distal midpalmar region was elevated on the basis of the common and proper palmar digital artery. Measurement of the rotation arc revealed that the pivot point of this flap was located at the proximal interphalangeal joint level and could cover the finger pulp of the digits. The second flap candidate was that from the radial aspect of the midpalm, which was supplied by the terminal branch of the superficial palmar arch. In studies with cadaver hands, connection of this artery with the deep arterial system enabled this flap to reach the thumb pulp. These flaps may be a useful reconstruction option for significant palmar soft-tissue loss of the fingers.     

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.     

Innervated radial thenar flap combined with radial forearm flap transfer for thumb reconstruction

A radial thenar flap combined with radial forearm flap was used for the reconstruction of the ipsilateral thumb in four patients. Vascular supply of the combined flap was based on the radial artery and extending the vascular pedicle to the superficial palmar branch of the radial artery. The flap was sensated by the palmar branch of the superficial radial nerve. The size of the flap averaged 15 x 5 cm and the innervated region of the thenar eminence was an area approximately 5 x 3 cm located over the proximal parts of the abductor pollicis brevis and opponens pollicis muscles. The flap was transferred as a free flap in three patients and as an advancement flap in one patient. The flaps survived completely without complications. Satisfactory restoration of sensation was achieved in the flap area, as shown by 6 mm of average moving two-point discrimination. This combined flap may be a feasible reconstructive option for large palmar defects of the fingers such as degloving injuries.     

Primary closure of radial forearm flap donor defects with a bilobed flap based on the fasciocutaneous perforator of the ulnar artery

To primarily repair a series of radial forearm flap donor defects, a total of 10 bilobed flaps based on the fasciocutaneous perforator of the ulnar artery were designed at the Chang Gung Memorial Hospital in Kaohsiung in the period from January of 2002 to January of 2003. All patients were male, with ages ranging from 36 to 67 years. The forearm donor defects ranged in size from 5 x 6 cm to 8 x 8 cm, with the average defect being 47 cm. One to three sizable perforators from the ulnar artery were consistently observed in the distal forearm and were most frequently located 8 cm proximal to the pisiform, which could be used as a pivot point for the bilobed flap. The bilobed flap consisted of two lobes, one large lobe and one small lobe. With elevation and rotation of the bilobed flap, the large lobe of the flap was used to repair the radial forearm donor defect and the small lobe was used to close the resultant defect from the large lobe. All bilobed flaps survived completely, without major complications, and no skin grafting was necessary. Compared with conventional methods for reconstruction of radial forearm donor defects, such as split-thickness skin grafting, the major advantage of this technique is its ability to reconstruct the donor defect with adjacent tissue in a one-stage operation. Forearm donor-site morbidity can be minimized with earlier hand motion, and better cosmetic results can be obtained. Furthermore, because a skin graft is not used, no additional donor area is necessary. However, this flap is suitable for closure of only small or medium-size donor defects. A lengthy postoperative scar is its major disadvantage.     

The lateral supramalleolar flap

An anatomic study (40 fresh dissected specimens) and clinical experience (14 patients) have shown the reliability of a skin flap designed on the lower third of the lateral aspect of the leg. It is supplied by a cutaneous branch from the perforating branch of the peroneal artery. This perforating branch continues distally deep to the fascia along the anterior ankle and into the foot. This can be used as a reversed pedicle, giving the flap an arc of rotation that allows coverage of the dorsal, lateral, and plantar aspects of the foot, the posterior heel, and the lower medial portion of the leg.     

The vascular supply of the extended tensor fasciae latae flap: how far can the skin paddle extend?

The vascular supply of the tensor fasciae latae flap and of the lateral thigh skin was studied in 10 cadavers to evaluate whether the lateral thigh skin toward the knee could be incorporated into an extended tensor fasciae latae flap. Within each cadaver, vascular injection of radiopaque material preceded flap elevation in one limb and followed flap elevation in the contralateral limb. Flaps raised after vascular injection were examined radiographically to evaluate the vascular anatomy of the lateral thigh skin independent of flap elevation. When vascular injection was made into the profunda femoris, the upper two-thirds of the flaps was better visualized than the distal third. When the injection was made into the popliteal artery, the vasculature of the distal third of the flaps was better visualized. Flaps raised before vascular injection were examined radiographically to delineate the anatomical territory of the vascular pedicle that had been injected. In these flaps, consistent cutaneous vascular supply was only seen in the skin overlying the tensor fasciae latae muscle, confirming that musculocutaneous perforators are the predominant means by which the pedicle of the tensor fasciae latae flap supplies the skin of the lateral thigh. Extended tensor fasciae latae flaps were elevated bilaterally in one cadaver, and selective methylene blue injections were made into the lateral circumflex femoral artery on one side and into the superior lateral genicular artery on the contralateral side. Methylene blue was observed in the proximal and distal thirds of the skin paddles, respectively, leaving unstained midzones. The vascular network of the lateral thigh skin could be divided into three zones. The lateral circumflex femoral artery and the third perforating branches of the profunda femoris artery perfuse the proximal and middle zones of the lateral thigh skin, respectively. The superior lateral genicular artery branch of the popliteal artery perfuses the distal zone. The middle and distal zones meet 8 to 10 cm above the knee joint, where the skin paddle of the tensor fasciae latae flap becomes unreliable. These data indicate that if the aim is to incorporate the skin over the distal thigh in an extended tensor fasciae latae flap without resorting to free-tissue transfer, then either a carefully planned delay procedure or an additional anastomosis to the superior lateral genicular artery is required.     

The lateral intercostal neurovascular free flap

The lateral intercostal flap is a new neurovascular flap that may be used as a free or island flap. It is based on the lateral cutaneous branch of a single posterior intercostal neurovascular bundle. The donor area of the flap is the anterolateral skin of the abdomen. The flap is large, thin, and has a long pedicle that contains the lateral cutaneous nerve. The donor pedicles of the flap are multiple, and its venous drainage is adequate. The detection and design of this flap were based on information gained from the dissection of 95 intercostal spaces in 40 fresh cadavers. The flap was then applied 12 times in 11 patients. Ten flaps were successful, one flap was partially lost, and one was completely lost. The flap was used as a noninnervated flap to resurface six defects in the neck and one facial defect, and it was used as an innervated flap to cover two hand defects and two heel defects.     

A new island flap transfer from the dorsum of the index to the thumb.

We describe here a new island flap from the dorsum of the index finger, transferred on the first dorsal metacarpal artery with one or two veins and the terminal branches of the radial nerve. This vascular bundle is a reliable one, for we have had no necrosis in 12 consecutive cases. The quality of its venous outflow and the use of a dorsal donor site give it advantages over the Moberg-Littler island flap, unless a dorsal vein from the latter flap is preserved and sutured to a vein in the recipient site. The arterial vascularization without any skin pedicle makes this "kite" flap a more practical one than the "flag" flaps of Vilain or Holevitch or Kuhn. Finally, a one-stage transfer is usually preferable to a two-stage one (e.g. Adamson, Braillar). In a single operation, this transfer provides composite resurfacing of the thumb while bringing in new blood and nerve supply.     

The radial forearm skin graft-fascial flap

The radial forearm flap has become a versatile flap for upper extremity reconstruction. The use of the forearm flap for hand reconstruction in the patient with previously burned forearms has not been widely appreciated. In those patients whose forearms have been previously split-thickness skin-grafted on fascia, we have employed the reverse radial forearm flap as a skin graft-fascial flap for hand reconstruction and have obtained excellent functional results. Three patients at various intervals postburn are presented to demonstrate use of this flap for wrist contracture release, coverage of arthroplasties, first web space contracture release, and acute salvage of phalanges and tendons. Assessment of the hand's vascular anatomy and careful treatment of the donor area have contributed to no added morbidity and an excellent aesthetic result at the donor site.     

Fasciocutaneous vessels in the upper arm: application to the design of new fasciocutaneous flaps

The principles of the blood supply to the upper arm are described. Despite the large, fleshy nature of the biceps and the triceps, the blood supply to upper arm skin is not from the underlying muscles, but is by fasciocutaneous perforators emerging along the medial and lateral intermuscular septa. Fifty dissections of preserved cadavers have shown that on the lateral side the fasciocutaneous perforators consistently arise from the middle collateral artery. The available length of this vessel and its diameter have been measured and are reported. The design of a flap based on this vessel, in a manner analogous to the Chinese forearm flap on the radial artery, is described.     

The prepuce free flap in 10 patients: modifications in flap design and surgical technique

The prepuce free flap was used in 10 oral and oropharyngeal reconstructions. During the course of this study, various modifications took place. Residual penile skin necrosis and skin island necrosis early in the series led to modification of flap design. This solved the donor-site problem by placing the skin island more proximally, to consist of the outer layer of the prepuce and an equidimensional area of penile skin proximal to the prepuce. Identification of the vascular pedicle was greatly facilitated by changing to retrograde dissection, making skin incision in the mons veneris superfluous. Incongruence between donor and recipient artery, together with microsurgical arrogance, resulted in (resolvable) inflow problems in four patients. One flap was lost. After modification, marginal necrosis still occurred in one flap, most likely because of an episode of venous congestion. Although much care was taken to not harvest more skin than in a regular circumcision, penile skin shortage, especially during erection, appeared to be the major long-term shortcoming of this flap. Flap thinness and pliability, both expected strongholds of the flap, were evident during flap inset, but less apparent during follow-up because of postoperative radiotherapy in the majority of the cases. The best indications for this flap include defects in the tonsillar area extending into the soft palate, tongue, lateral oropharynx, retromolar trigonum, gums, and vallecula.     

Vascular dominance in the forearm

The dominance of the radial or ulnar artery at the forearm level and their contributions to the circulation of the hand remain a matter of contention. Therefore, the authors proposed to investigate the predominance of one of these arteries first by anatomic studies on 40 fresh cadaver upper extremities, and then by dynamic studies. The dynamic studies included color Doppler sonography in 22 individuals (44 hands) and five-channel plethysmography in 40 individuals (40 right hands). It was found that the ulnar artery is dominant at the elbow, but after originating its collateral branches, the radial artery becomes the dominant artery in the distal forearm and, consequently, constitutes the major source of vascularization to the hand. The ulnar artery is rarely dominant at the forearm level and is physiologically less important. Therefore, there is no hemodynamic reason to prefer the radial artery to the ulnar artery for any invasive maneuvers.     

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.     

Free flap from the flexor aspect of the wrist for resurfacing defects of the hand and fingers

The distal portion of the flexor aspect of the forearm has been used as the donor site of full-thickness skin grafts, venous skin grafts, and Chinese forearm flaps. This article describes the use of a free flap harvested from the flexor aspect of the wrist and based on the superficial palmar branch of the radial artery to repair skin defects of the hand and fingers. The advantages of this flap are as follows: (1) the operative field is the same; (2) the radial artery is preserved; (3) it is thin, pliable, and hairless and thus can supply a gliding surface for tendons beneath it; (4) when it involves a palmaris longus tendon and/or the palmar cutaneous branch of the median nerve, it can be used as a vascularized tendon or nerve graft; and (5) in view of the flow-through type of the pedicle of the flap, the digital artery can be reconstructed simultaneously. However, it should be noted that a hypesthesia in the proximal central carpal area remains when the palmar cutaneous branch of the median nerve is harvested as a vascularized nerve graft. The scar of the donor site should be left in the distal wrist crease. If it is not lying in the distal wrist crease, it may suggest that the patient has tried to commit suicide.     

Vascular anatomy of the forearm muscles: a study of 50 dissections

This anatomic study is based on 50 adult cadaver upper extremities. The general disposition of the forearm arteries and muscles and the main anatomic variations encountered are specified. Constant existence of an "anterior oblique artery" satellite of the pronator teres was established. The median nerve artery was principally dedicated to the flexor digitorum superficialis and participated appreciably in the constitution of palmar arches in only one case. A supernumerary intermedial radial muscle was found only in two cases. The abductor pollicis longus and extensor pollicis brevis appeared as a single muscular and vascular unit in 84 percent of cases. All the arteries destined for muscles were reckoned whatever their caliber might be. Despite its limitations, this study confirms the very great number of the forearm muscular pedicles. Each forearm contained an average of 264 muscular vascular pedicles. The systematization of the origins and destinations of the 13,158 muscular pedicles is described in a numbered manner for each of the 20 normal forearm muscles and for each of the 12 studied arterial segments. The pronator teres was likely to be supplied by all the anterior arteries of the upper limb. The flexor carpi radialis had one or two dominant pedicles originated from the recurrens ulnaris anterior, recurrens ulnaris, or ulnaris-interossea communis arteries, and many transversal branches originated from the radial artery. The flexor carpi ulnaris was supplied in its proximal third by the recurrens ulnaris posterior artery and in its distal two-thirds by many branches of ulnar artery.(ABSTRACT TRUNCATED AT 250 WORDS)