Bilobed Chest Flap (Deltopectoral Skin Flap and Pectoralis Major Musculocutaneous Flap)
R. M. MEYER
Use of an external large flap to cover the esophageal reconstruction may be unnecessary, because the pectoralis major muscle can be covered and closed easily with a split-thickness skin graft. If this procedure is attempted with the pectoralis major muscle and the ipsilateral deltopectoral flap is used, then the surgeon must ensure that the second intercostal vessel is maintained to retain blood supply to the deltopectoral flap.
The bilobed chest flap is a double cutaneous and musculocutaneous flap used for head and neck reconstruction. The flap incorporates the pectoralis major musculocutaneous flap and the medially based cutaneous deltopectoral flap in a single bilobed unit. Both flaps come from the ipsilateral chest and provide for both reconstruction of pharyngoesophageal wall defects and external cutaneous coverage in one stage.
FIGURE 221.1 A,B: Outline of the bilobed flap. (From Meyer et al., ref. 2, with permission.)
Solutions to the problem of external coverage at flap donor sites have been numerous, and I have used six alternative methods, according to the type of repair. In my experience with 78 pectoralis major musculocutaneous flaps, I have used the following methods for closure or cover of the external defect (1, 2, 3):
Skin approximation and suture (21 patients)
Using a part of the pectoralis major musculocutaneous flap for two patches (31 patients)
Split-thickness skin grafts (18 patients)
Advancement shoulder flaps (4 patients)
Contralateral deltopectoral flaps (3 patients)
Ipsilateral deltopectoral flap (1 patient)
The last method is the subject of this chapter (i.e., the use of the pectoralis major musculocutaneous flaps for pharyngoesophageal reconstruction, combined with the ipsilateral medially based deltopectoral flap for cutaneous coverage). The ipsilateral musculocutaneous and cutaneous flaps, having a common base, thus form a single bilobed flap.
FLAP DESIGN AND DIMENSIONS
The bilobed chest flap is composed of two standard flaps: the pectoralis major musculocutaneous flap and the deltopectoral cutaneous flap. The two flaps share a common base, starting approximately 3 to 4 cm below the medial end of the clavicle and continuing cranially and laterally to the anterior part of the neck. The design of the two flaps resembles an open V (Fig. 221.1). The outline of the musculocutaneous portion of the bilobed flap should be centered on the thoracoacromial artery.