ATC is a rare malignancy and accounts for around 1–2% of all thyroid malignancies [1]. This carcinoma shows fast growth, strong invasiveness in the adjacent tissues, and a high rate of metastasis into the regional lymph nodes (42%) and distant organs (32%) [3, 5, 9]. Most cases (about 80%) are diagnosed in later stages and already have disease progression to the surrounding tissue and organs and distant metastasis [2, 6]. Various therapeutic modalities, including surgery, chemotherapy, and external beam radiotherapy, have been reported for these tumors [2,3,4, 10, 11]. Apart from these therapeutic modalities, second-line treatments, including tyrosine kinase inhibitors, have been explored in ATC patients and resulted in acceptable treatment responses [10, 12,13,14]. However, the ATC patients’ median overall survival is 4–8 months [2]. In many cases, the surgery for local disease management cannot be applied because of the advanced tumor, and palliative resections are not recommended because of the risk of increased morbidity [15]. Most patients die due to uncontrolled local tumor invasion or distant metastases.
Our patient’s tumor extended very fast into surrounding tissue and could not be resected completely. The patient reported a significant deterioration in her mental state, and she was under high psychological stress because of her neck deformity and the foul smell. She had difficulty fitting into family and society because of the large visible exulcerated tumor. In such cases, palliative tumor debulking can significantly improve the mental state despite the poor prognosis and short life expectancy. However, skin defects that form after tumor resection need reconstructive surgery, accelerating wound healing and facilitating the rapid application of local and systemic oncological therapy. The skin flaps should be easy to manage and have fewer complications. The primary closure of the donor site is also essential for flap selection. Therefore, we chose the IMAP island flap.
Yu et al. first described the IMAP flap for reconstructing tracheostomy and anterior neck defects. A thin and pliable fasciocutaneous flap is well suited to anterior neck defects—this flap is based on the deltopectoral axis [7]. Bakamjian et al. first described the deltopectoral flap as a pedicle flap based on the first four internal mammary perforators. These numerous perforators subsequently restrict flap mobility. Also, the deltopectoral flap requires skin grafting to the donor site defect because primary closure is difficult, which delays the healing process [16]. The IMAP flap can be islanded on a single perforator and therefore have a significantly longer arc of rotation than the deltopectoral flap [17,18,19,20]. Moreover, most authors also describe the possibility of immediate skin closure at the donor site for nearly all patients [17, 18, 18].
The perforator can be determined using a handheld Doppler device within a 1–3 cm lateral to the sternal border [20]. The flap can be raised on any perforator in the first five intercostal spaces [19]. Most flaps are based on the internal mammary perforator at the second or third intercostal space. The second has been shown to have the largest diameter perforator (1.6 ± 0.5 mm, range 0.9–2.3 mm) with an average pedicle length of 3.6 cm and perfuse the largest skin dimensions (15 × 8 cm) [18, 21, 22]. The flap is then designed around the perforator, usually obliquely or parallel to the intercostal space towards the axilla. The flap is dissected from lateral to medial and from distal to cranial. The dissection is made in a subfascial plane and proceeds until the pedicle of the internal mammary artery is identified. The flap is isolated as an islanded flap. The blood supply by only one perforator of the internal mammary vessels allows more versatility in flap design and increases the arc of rotation; the rotation can be from 90° to 180°. The flap can be brought to the neck defect through a subcutaneous tunnel, or the skin bridge between the neck and donor site can be divided. Flap sizes from 5 × 3 cm to 15 × 8 cm are reported in the literature [18]. The flap can be in a relatively short time harvest; the inset is simple [23]. The donor site, in most cases, can be primarily closed, and there are usually no side effects such as skin necrosis [18]. The IMAP flap is a reliable option that provides well-vascularized tissue ideal for reconstructing the lower neck where thin, pliable tissue is needed. Flap harvest and inset are simple, while primary closure of the donor site is a definite advantage in minimizing morbidity.
In conclusion, the palliative resection of the advanced anaplastic thyroid carcinoma and plastic reconstruction of the neck defect can promote other oncological treatments such as radiation or chemotherapy due to improved local situation. The application of the IMAP flap is a good option for neck reconstruction in such cases due to easy elevation, reliable blood supply, and minimal donor site morbidity.
