Fig. 5
From: Posterior intercostal flap: an anatomical study and best flap design
a A photograph of the left side of the back showing 3 medial zone perforators (P1, P2, and P3). The lower 2 perforators divide in the skin into lateral and medial branches (a, b). The latissimus dorsi (Ld), serratus posterior superior muscle (SPS), and midline of the back (M) are noted. b A photograph of the lower part of the previous specimen showing medial zone perforators (P1–P4) on the medial border of erector spinae muscles (Es). P4 is the largest and longest one; it comes of the 8th space and divides into lateral and medial branches (a, b). Branch (a) further divides into branches (1, 2) that supply latissimus dorsi (Ld) and pass to the skin. Two intermediate zone perforators (Pi) are noted. c A photograph of the previous specimen after further dissection. Five intermediate perforators (Pi) are seen at the lateral border of erector spinae muscles (Es). They supply latissimus dorsi (Ld) and reach the skin by passing through the muscles or around its lower border as perforators (1, 2, 3)