The reconstructive ladder in head and neck oncologic resections has largely shifted toward free tissue transfer because local flaps are often of inadequate size and regional flaps are often bulky and hard to inset in intricate defects and carry significant donor site morbidity. However, microsurgery is not without drawbacks. It requires time and expertise, and not all patients are candidates due to comorbidities or lack of recipient vessels.[8,9]
The growing knowledge of the angiosome of the supraclavicular artery led Pallua and colleagues[6,7] to rediscover the SAP flap. Since then, it has been used in neck, tracheostomal, pharyngeal wall, mandible, parotid, and posterolateral skull base defects.[8,9] In 1999, Liu and Chiu reported the first series of SAP flaps for partial or circumferential pharyngeal defects.
The supraclavicular artery branches from the transverse cervical artery (TCA) in a triangle formed by the external jugular vein, the sternocleidomastoid muscle, and the clavicle. In 90% of the cases, it arises from the middle third of the clavicle and in the remaining from the lateral third. After a short course perpendicular to the TCA, the supraclavicular artery turns toward the acromioclavicular joint and the ventral surface of the deltoid muscle. The mean distance between the origin of the supraclavicular artery and the sternoclavicular joint is on average 7.45 cm, and it has a mean course of 3.75 cm before piercing the deep fascia.[5,9,11,12] When possible, the flap should be harvested on the right to avoid thoracic duct injury. Previous neck irradiation and previous or concurrent nodal dissection level IV/V are not contraindications to SAP flap harvest.[5,13]
Concerning flap dimensions, on a reported series of 103 SAP flaps, the authors suggest that a size of 22 × 10 cm can be elevated safely. Larger flaps may require skin grafting the donor site, and longer flaps should be supercharged. In our experience, flaps wider than 7 cm required skin grafting.
To increase the reach of the flap, it is possible to ligate the TCA distally to the supraclavicular artery origin. This way the pivot point of the flap becomes the origin of the TCA in the thyrocervical trunk. In our series, there was no need to perform this step. In all dissections, we did not skeletonize the vessels and preserved a fascial pedicle of approximately the width of the flap. This technique, described by Di Benedetto et al, ensures good reliability and protects the pedicle from tension or kinking. In addition, it makes flap harvesting easier and quicker.
Pallua and Wolter have recently described a variation of the original SAP flap, called the anterior supraclavicular artery perforator (a-SAP) flap. This flap should be designed toward the deltoideo-pectoral fossa and is perfused by the anterior supraclavicular artery that also originates from the TCA. This flap can be longer than the classic SAP flap reaching 35 cm and has the additional vantage of being even more thin.
In our small series, the SAP flap proved to be very useful in pharyngoesophageal reconstruction. Three patients had pharyngocutaneous fistulas and 2 had tracheoesophageal fistulas. The latter underwent reconstruction with an SAP flap with 2 skin paddles in order to achieve a 2-layer closure. Patient 2 had a nearly complete circumferential defect and the reconstruction was uneventful. Other regional options, such as the internal mammary artery perforator, pectoralis major, or deltopectoral flaps, are often bulky, of insufficient size, or associated with more morbidity. Although muscle flaps atrophy, in pharyngeal reconstructions, it can lead to strictures. Besides that, muscle bulk can preclude primary neck closure and cause obstruction of the tracheostoma.[8,13] Free tissue transfer (radial forearm, jejunal, and anterolateral thigh flaps) should be considered essentially backup options.
One patient with pharyngocutaneous fistula (patient 3), prior radiation therapy, and 2 failed attempts of reconstruction with pectoralis major flap had persistent leaking that required initiation of negative pressure wound therapy with fistula closure after 2 months. Negative pressure wound therapy has been described as an effective treatment option in initial or recurrent pharyngocutaneous fistulas. We do not believe that leaking was due to partial flap necrosis because it healed without further surgical intervention, the flap was well perfused after inset, and native tissues were not healthy. Patient 5 had an expected leaking in the inferior border of the flap due to fistulization from the pyriform sinus. The achieved goal was to ameliorate the local conditions in order to support radiation therapy. Patient 6 had reexposure of the plate through the SAP flap. The thinness of the flap may make it less suitable for these reconstructions. However, the flap may have been placed under slight tension (Figures 3a-3d).
No donor site complications were found beyond hematoma and slight scar enlargement. No functional shoulder morbidity was reported. For cutaneous defects, the thickness, color, and texture match were very good. The SAP flap is also relatively hairless, which is beneficial in mucosal reconstructions. Excluding patient 6, who required a second flap, the remaining functional and esthetic outcomes were very good.
The SAP flap is reliable, is quick to harvest, has excellent color match to head and neck, and entails minimal donor site morbidity. Also, it is thin, is pliable, and has a wide arc of rotation from the skull base to esophagus, making it extremely versatile in small-volume tridimensional defects. It is an emerging alternative that should be added to the spectrum of solutions of any head and neck reconstructive surgeon.
ePlasty. 2020;20(e7) © 2020 Open Science Company