Keystone design perforator island flap in facial defect reconstruction

Figure 4 Schematic diagram showing the relaxed skin tension line-oriented keystone design perforator island flap considering the nasal unit. Red-colored ellipses represent defects and yellow-colored figures represent the design of keystone design perforator island flap. 1: Tip subunit; 2: Columellar subunit; 3, 6: Right and left alar base subunits; 4, 5: Right and left alar side wall subunits; 7: Dorsal subunit; 8, 9: Right and left dorsal side wall subunits. (Reprinted from Yoon et al[1], with permission from Wolters Kluwer, which was originally reprinted from Fattahi, with permission from Elsevier).