The superior thyroid artery perforator flap: anatomical study and clinical series

The redundant tissues of the anterior neck are well suited as a donor site for fasciocutaneous flaps in head and neck reconstruction, with similar skin quality and numerous underlying perforators. However, historic cadaveric research has limited the use of this as a donor site for the design of long and/or large flaps for fear of vascular compromise. The authors undertook an anatomical study to identify the vascular basis for such flaps and have modified previous designs to offer the versatile and reliable superior thyroid artery perforator (STAP) flap. Forty-five consecutive computed tomographic angiograms of the neck were reviewed, assessing the vascular supply of the anterior skin of the neck. Based on these findings, eight consecutive patients underwent head and neck reconstruction using a flap based on the dominant perforator of the region. In all cases, a perforator larger than 0.5 mm was identified within a 2-cm radius of the midpoint of the sternocleidomastoid muscle at its anterior border. This perforator was seen to emerge through the investing layer of deep cervical fascia as a fasciocutaneous perforator and to perforate the platysma on its ipsilateral side of the neck, proximal to the midline. This was seen to be a superior thyroid artery perforator in 89 of 90 sides and an inferior thyroid artery perforator in one case. Eight consecutive patients underwent preoperative imaging and successful flap planning and execution based on this dominant perforator. The superior thyroid artery perforator (STAP) flap demonstrates reliable vascular anatomy and is well suited to reconstruction of a broad range of head and neck defects. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.     

Extended approach to the vascular pedicle of the gracilis muscle flap: anatomical and clinical study

Dissection of the proximal gracilis vascular pedicle proceeds in a dark tunnel-like space deep to the adductor longus. With the application of a previously described technique for an extended approach to the lateral arm free flap, the authors describe a novel technique that improves observation and thus facilitates dissection of the proximal gracilis vascular pedicle. A retrospective review of data for 18 consecutive patients who underwent gracilis muscle free flap harvesting with this modified technique between March of 1999 and October of 2001 was conducted, to assess flap viability and patient outcomes. A cadaveric dissection was also performed, to study the anatomical features of the region in depth and to test the proposed flap modification. After the standard incision has been made, the dominant pedicle is exposed on the medial aspect of the gracilis muscle, running in a fascial cleft between the adductor longus and the adductor magnus. Intramuscular branches to the adductor longus are divided. A space is bluntly created anterior and lateral to the adductor longus by separating the fibrous connections to the surrounding adductor and sartorius muscles on both sides of the vascular pedicle. The gracilis muscle is then divided and passed deep to the adductor longus, into this space. With this new position, the final dissection of the pedicle can easily be performed. The confluence of the venae comitantes is frequently encountered, providing a larger-caliber single vein for microvascular anastomosis. The ages of the patients ranged from 9 to 70 years. The majority (14 of 18 patients) had traumatic wounds. The free flap survival rate was 100 percent. One minor complication of a seroma at the donor site was observed. One major complication of venous thrombosis was detected on postoperative day 3, with complete flap salvage. No other complications were noted. This technique is safe and permits direct approach to and excellent observation of the proximal aspect of the gracilis pedicle, without the need for headlights or deep retractors. An additional benefit is the frequent finding of a single larger vein from the merging of the venae comitantes close to the deep femoral vessels.     

The lower trapezius musculocutaneous flap from pedicled to free flap: anatomical basis and clinical applications based on the dorsal scapular artery

The pedicled lower trapezius musculocutaneous flap is a standard flap in head and neck reconstruction. A review of the literature showed that there is no uniform nomenclature for the branches of the subclavian artery and the vessels supplying the trapezius muscle and that the different opinions on the vessels supplying this flap lead to confusion and technical problems when this flap is harvested. This article attempts to clarify the anatomical nomenclature, to describe exactly how the flap is planned and harvested, and to discuss the clinical relevance of this flap as an island or free flap. The authors dissected both sides of the neck in 124 cadavers to examine the variations of the subclavian artery and its branches, the vessel diameter at different levels, the course of the pedicle, the arc of rotation, and the variation of the segmental intercostal branches to the lower part of the trapezius muscle. Clinically, the flap was used in five cases as an island skin and island muscle flap and once as a free flap. The anatomical findings and clinical applications proved that there is a constant and dependable blood supply through the dorsal scapular artery (synonym for the deep branch of the transverse cervical artery in the case of a common trunk with the superficial cervical artery) as the main vessel. Harvesting an island flap or a free flap is technically demanding but possible. Planning the skin island far distally permitted a very long pedicle and wide arc of rotation. The lower part of the trapezius muscle alone could be classified as a type V muscle according to Mathes and Nahai because of its potential use as a turnover flap supplied by segmental intercostal perforators. The lower trapezius flap is a thin and pliable musculocutaneous flap with a very long constant pedicle and minor donor-site morbidity, permitting safe flap elevation and the possibility of free-tissue transfer.     

The innervated anterolateral thigh flap: anatomical study and clinical implications

During the past 20 years, the neural anatomy of many flaps has been investigated, although no extensive studies have been reported yet on the anterolateral thigh flap. The goal of this study was to describe the sensory territories of the nerves supplying the anterolateral thigh flap with dissections on fresh cadavers and with local anesthetic injections in living subjects. The sensate anterolateral thigh flap is typically described as innervated by the lateral cutaneous femoral nerve. Two other well-known nerves, the superior perforator nerve and the median perforator nerve, which enter the flap at its medial border, might have a role in anterolateral thigh flap innervation. Twenty-nine anterolateral thigh flaps were elevated in 15 cadavers, and the lateral cutaneous femoral nerve, the superior perforator nerve, and median perforator nerve were dissected. In the injection study, the lateral cutaneous femoral nerve, superior perforator nerve, and median perforator nerve in 16 thighs of eight subjects were sequentially blocked. The resulting sensory deficit from each injection was mapped on the skin and superimposed on the marked anterolateral thigh flap territory. The study shows that the sensate anterolateral thigh flap is basically innervated by all three nerves. The lateral cutaneous femoral nerve was present in 29 of 29 thighs, whereas the superior perforator nerve was present in 25 of 29 and the median perforator nerve in 24 of 29 thighs. Furthermore, in the proximal half of the flap, the lateral cutaneous femoral nerve lies deep, whereas the superior perforator nerve and median perforator nerve lie more superficially. Whereas the lateral cutaneous femoral nerve innervates the entire flap, the superior perforator nerve innervates 25 percent of the flap and the median perforator nerve innervates 60 percent of the flap. Clinically, a small anterolateral thigh flap (7 x 5 cm) can be raised sparing the lateral cutaneous femoral nerve and using only the selective areas innervated by the superior perforator and median perforator nerves. Alternatively, a large anterolateral thigh flap can be raised with this multiple innervation. This can be helpful if one wants to harvest the flap under local anesthesia. Sensate bilobed flaps can be harvested when dual innervated flaps are required.     

Tendofascial island flap based on distal perforators of the radial artery: anatomical and clinical approach

The possibility of transferring vascularized tissue to restore function and to resurface large defects, together with the use of composite flaps, has led to recent advances in "one-stage" reconstructive surgical procedures. On the basis of a previous study of the blood supply of the adipofascial flap and a new study of the blood supply of the flexor carpi radialis tendon from the transfascial and direct branches of the radial artery, a fascial island flap complete with tendon was devised and used to treat four male patients who had sustained traumatic soft-tissue losses on the dorsum of the hand and segmental losses of the extensor digitorum communis. The use of a completely vascularized, single-stage, composite flap did not involve sacrifice of the radial artery, the functional and aesthetic results were good, and there was minimal donor-site morbidity.     

Extensor digitorum brevis free flap: anatomic study and further clinical applications

The extensor digitorum brevis muscle flap is reliable, safe, and can be used either as a pedicle or as a free flap with minimal donor site morbidity. To increase the existing knowledge of this flap and to establish further anatomic basis for the design and elevation of the extensor digitorum brevis flap, 26 specimens from 13 fresh cadavers were dissected under 3.5x loupes. The lateral tarsal artery was found to be the main blood supply to the muscle. It has an average diameter of 1.83+/-0.35 mm and a length of 1.89+/-0.69 cm. The dorsalis pedis artery has, at the level of the lateral tarsal artery takeoff, a diameter of 3.25+/-0.62 mm. From this point to the origin of the deep plantar branch, the dorsalis pedis artery has minimal branching, and the surgeon has available an artery homogeneous in diameter that is 6.77+/-0.99 cm in length. Related neurovascular structures (anterior tibial artery and the venae comitantes, dorsalis pedis and first dorsal metatarsal artery, and deep peroneal nerve) were also studied. A safe and reliable harvesting technique and the "T interposed extensor digitorum brevis" technique for sparing the anterior tibial artery are presented, as are clinical case examples on the use of this flap as a flow-through, extensor digitorum brevis-vascularized nerve graft, a combined extensor digitorum brevis-deep peroneal nerve graft, and a bilobed extensor digitorum brevis-dorsalis pedis fasciosubcutaneous free flap.     

Distally based anterolateral thigh flap: an anatomic and clinical study

The distally based anterolateral thigh flap has been used for coverage of soft-tissue defects of the knee and upper third of the leg. This flap is based on the septocutaneous or musculocutaneous perforators derived from the lateral circumflex femoral system. The purpose of this study was to examine the results of anatomical variations of the descending branch of the lateral circumflex femoral artery and the retrograde blood pressure of the descending branch of the lateral circumflex femoral artery so that the surgical technique for raising and transferring a distally based anterolateral thigh flap to the knee region could be improved. The authors have actually used this flap in three cases. In 11 thighs of six cadavers, the descending branch of the lateral circumflex femoral artery had a rather consistent connection with the lateral superior genicular artery or profunda femoral artery in the knee region. The pivot point, located at the distal portion of the vastus lateralis muscle, ranges from 3 to 10 cm above the knee. In their three cases, the maximal flap size was 7.0 x 16.0 cm and was harvested safely, without marginal necrosis. The mean pedicle length was 15.2 +/- 0.7 cm (range, 14.5 to 16 cm). The average proximal and distal retrograde blood pressure of the descending branch of the lateral circumflex femoral artery was also studied in another 11 patients, and the anterolateral thigh flap being used for reconstruction of head and neck defects showed 58.3 and 77.7 percent of proximal antegrade blood pressure, respectively. The advantages of this flap include a long pedicle length, a sufficient tissue supply, possible combination with fascia lata for tendon reconstruction, and favorable donor-site selection, without sacrifice of major vessels or muscles.