Correction of asymmetric pectus excavatum using a virtually designed silicone implant

Is breast asymmetry caused by volume differences in women with pectus excavatum?

This study determined the breast volumes of female patients with pectus excavatum that led to asymmetry and hypoplasia compared with normal women. This retrospective study enrolled 13 patients diagnosed with pectus excavatum and 13 normal women, randomly selected from a healthcare centre (n = 26), between January 2012 and December 2014. We measured breast volumes (n = 52) based on chest computed tomography (CT) of all patients using Image J software and divided them into four groups according to the side and presence of pectus excavatum. The mean volumes of the right and left breasts of patients with pectus excavatum were 209 ± 64 mL and 218 ± 67 mL, respectively, with no significant difference between the two groups (P = 0.736). The mean volumes of the right and left breasts of normal women were 415 ± 197 mL and 439 ± 197 mL, respectively, with no significant difference between the two groups (P = 0.754). The breasts of patients with pectus excavatum were significantly smaller than those of normal women (P < 0.001). Both breasts of patients with pectus excavatum were similar in size but were smaller than the breasts of normal women. Skeletal correction for breast asymmetry correction, followed by breast augmentation for breast hypoplasty correction, with a one- or two-step approach may be useful to improve the aesthetics of breast deformities in women with pectus excavatum.

3D-printed haptic "reverse" models for preoperative planning in soft tissue reconstruction: a case report

In reconstructive surgery, preoperative planning is essential for optimal functional and aesthetic outcome. Creating a three-dimensional (3D) model from two-dimensional (2D) imaging data by rapid prototyping has been used in industrial design for decades but has only recently been introduced for medical application. 3D printing is one such technique that is fast, convenient, and relatively affordable. In this report, we present a case in which a reproducible method for producing a 3D-printed "reverse model" representing a skin wound defect was used for flap design and harvesting. This comprised a 82-year-old man with an exposed ankle prosthesis after serial soft tissue debridements for wound infection. Soft tissue coverage and dead-space filling were planned with a composite radial forearm free flap (RFFF). Computed tomographic angiography (CTA) of the donor site (left forearm), recipient site (right ankle), and the left ankle was performed. 2D data from the CTA was 3D-reconstructed using computer software, with a 3D image of the left ankle used as a "control." A 3D model was created by superimposing the left and right ankle images, to create a "reverse image" of the defect, and printed using a 3D printer. The RFFF was thus planned and executed effectively, without complication. To our knowledge, this is the first report of a mechanism of calculating a soft tissue wound defect and producing a 3D model that may be useful for surgical planning. 3D printing and particularly "reverse" modeling may be versatile options in reconstructive planning, and have the potential for broad application.