Positional relationship between the pectoralis major and external abdominal oblique muscles for consideration during dual‐plane breast augmentation

Abstract

During dual plane breast augmentation (DPBA), the costal origin of the pectoralis major (the PM) should be cut to ensure appropriate coverage and positioning of an implant. However, surgeons sometimes make inappropriate planar incisions and insufficient muscular incisions because the external abdominal oblique (the EAO) muscle partially overlaps the lateral portion of the PM. The goal of this study was to clarify the positional relationship between the PM and EAO with the aim of improving the accuracy of implant and muscular incisions during DPBA. Forty sides of 20 embalmed and fresh cadavers were dissected. The midline and midclavicular line (MCL) were used as reference lines for measurements. We clarified the overlapping patterns between the PM and EAO, and measured the distances from the MCL to the borders of those two muscles. The costal part of the PM originated from the 5th (25%), 6th (70%), or 7th rib (5%), respectively. The distances from the MCL to the lateral border of the PM at the 4th, 5th, and 6th ribs were 49.8 mm, 30.5 mm, and 6.3 mm, respectively. In 90% of the specimens, the PM and the EAO overlapped near the MCL. The width of the overlapping portion between the PM and EAO was about 25 mm. This study is one of the first to suggest an innovative approach for explaining the positional relationships between the PM and EAO. Our findings can be useful for surgeons attempting to produce optimal outcomes in DPBA, especially in procedures that involve patients of different races. Clin. Anat. 31:339-346, 2018. © 2018 Wiley Periodicals, Inc.

Costal Cartilage Harvest Through a Small Incision in Asian Rhinoplasty After Breast Augmentation

“…11,12 Previous studies demonstrated that the costal part of the pectoralis major originated from the sixth rib on most occasions and the distance from the midclavicular line to the lateral border of the pectoralis major at the sixth rib was ~3 cm. 13,14 In addition, the pectoralis major and the external abdominal oblique overlapped near the midclavicular line with about 25 mm width of the overlapping portion. 13 Therefore, we recommend avoiding extensive separation in the subcutaneous and submuscular layers when the anatomic structures and the layer of the breast implant placements are not clear.…”

“…13,14 In addition, the pectoralis major and the external abdominal oblique overlapped near the midclavicular line with about 25 mm width of the overlapping portion. 13 Therefore, we recommend avoiding extensive separation in the subcutaneous and submuscular layers when the anatomic structures and the layer of the breast implant placements are not clear.…”

“…Although for the patients who have undergone breast augmentation, extensive separation has the potential of injuring the implants or producing a drawing force to the implants after scar healing because the implants were generally placed at the subglandular or submuscular plane 11,12. Previous studies demonstrated that the costal part of the pectoralis major originated from the sixth rib on most occasions and the distance from the midclavicular line to the lateral border of the pectoralis major at the sixth rib was ~3 cm 13,14. In addition, the pectoralis major and the external abdominal oblique overlapped near the midclavicular line with about 25 mm width of the overlapping portion 13.…”

Composite Sling: A Strategy for Enhancing Inferolateral Support in Mastopexy with Implant

“…In these situations, before the composite sling description, the abdominal portion of the pectoralis was usually incised completely, converting the pocket into a potentially high dual plane with a greater risk of insufficient inferolateral support. 6 In the majority of patients, implants are positioned with the lower edge extending over the first third of the sixth rib. However, in patients with a short chest, implants are lowered to the level of the sixth rib, reaching its lower one-third.…”