Posterior trunk defects result from diverse etiologies, such as pressure sores, tumor resection, infection, or trauma, and represent a challenging procedure. Myocutaneous flaps, such as the latissimus dorsi flap or trapezius flap, have been widely used to cover these defects [1-3]. Although these flaps are preferred by some authors because of simple and reliable techniques [4], they are associated with greater donor-site morbidity than perforator flaps.

The introduction of perforator flaps [5] has revolutionized reconstructive surgery over the past two decades. The application of perforator flap technique enables long and reliable vascular pedicles, thinner flaps with minimal donor-site morbidity and without including muscle tissue [6]. Intercostal artery perforator flaps have been used widely to cover the diverse trunk defects, based on an understanding of the anatomy of intercostal vessels [7-12]. Among them, dorsal intercostal artery perforator (DICAP) flaps have recently been described in posterior trunk reconstruction [13-17].

This paper describes a case of a large DICAP propeller flap for the reconstruction of extensive posterior trunk oncological defects.

The patient was a 70-year-old woman with neurofibromatosis I (von Recklinghausen’s disease) with the chief complaints of a giant mass on her left upper back that had been increasing in size gradually for 10 years (Fig. 1). Preoperative computed tomography showed a lesion, measuring 20×15×10 cm³, overlying the trapezius muscle and the infraspinous region of the scapula. Under general anesthesia, a wide local excision of the lesion was performed with a 2-cm margin. Frozen sections of the excision margins were free of tumor. The tumor was excised at a submuscular plane, including the trapezius, rhomboid major and minor, directly below the tumor. The soft tissue defect was approximately 25×20 cm² in size and a 30×18-cm² DICAP propeller flap was designed to close the defect based on the 6th posterior intercostal artery (Fig. 2). An exploratory incision was made, and a large perforator was identified (Fig. 3). The perforator flap was elevated at the subfascial level and transposed 90° into the defect. The donor site was closed directly and the remaining wound was covered with a split-thickness skin graft (Fig. 4). The flap healed uneventfully. Histopathology demonstrated a completely excised malignant peripheral nerve sheath tumor (MPNST). At 6 months postoperatively, the patient did not have any limitation in the range of motion or pain (Fig. 5). Written informed consent was obtained for publication of this case report and accompanying images.

Posterior trunk reconstruction may be a challenging procedure. Many different operative options have been used to cover the posterior trunk defect; each has distinct advantages and disadvantages. Myocutaneous flaps, such as the latissimus dorsi flap and the trapezius muscle flap, have long been the main treatment for posterior trunk reconstruction [1,2,18,19]. These flaps provide well-vascularized tissue and simple and reliable techniques, but they imply major donor-site morbidity (sacrifice of a major muscle), increased blood loss, and longer operative time. As a consequence, posterior trunk reconstruction has been addressed with perforator flaps, such as the thoracodorsal artery perforator flap or the intercostal artery perforator flaps [9,19].

There are multiple perforating vessels in the dorsal area, and the anatomy of intercostal vessels has been studied extensively [7]. The DICAPs arise from the posterior intercostal artery at the vertebral segment. Consistent with the angiosome theory and recently published studies [20], the DICAP flap can be extended safely to capture adjacent perforasomes because of the extensive true anastomotic connections with the multiple surrounding perforators [10]. To date, the biggest DICAP flap elevated on a single perforator reported thus far was a 40×15 cm² propeller flap by Prasad and Morris [17].

The size of the flap in the present case was slightly smaller (30×18 cm²), but it extended from the posterior midline to approximately the midaxillary line based on a single perforator. The flap was elevated safely and healed uneventfully without tip necrosis or congestion. There were some technical points and originalities with satisfactory results. First, MPNST is biologically an aggressive tumor, and its excision is difficult because of the intractable hemorrhage. Maintaining a bloodless field is paramount to ensuring clear visualization of the perforating vessels and safe excision. To accomplish that, a wide local excision of the lesion was performed with a 2-cm margin three-dimensionally, not only for the tumor clearance but also for the inclusion of normal tissue for less bleeding. In addition, an MPNST excision is performed with the generous use of bipolar electrocautery. Second, an exploratory incision (4 cm) was made first, and a perforator adjacent to the defect was explored. After identifying the large perforator, the skin islands were redesigned according to the perforator location and the size of the defect. The isolated perforator is mobilized and dissected free with the overlying to prevent flap congestion and to gain sufficient pedicle length without tension. According to the anatomical study and clinical applications of DICAP flap [16], it could safely be extended as far as the midaxillary line or the anterior border of the latissimus dorsi with stable blood circulation and complete survival.

As described above, successful reconstruction of the back was possible using a DICAP propeller flap. Although there is a limitation that requires long-term follow-up, a DICAP propeller flap offered a satisfactory result in the present patient. Overall, this technique offers early recovery with minimal donor-site morbidity.