Description
Pectus excavatum is the most common deformity of the thorax. A minimally invasive surgical correction is commonly
carried out to remodel the anterior chest wall by using an intrathoracic convex prosthesis in the substernal position. The
process of prosthesis modeling and bending still remains an area of improvement. The authors developed a new system,
i3DExcavatum, which can automatically model and bend the bar preoperatively based on a thoracic CT scan. This article
presents a comparison between automatic and manual bending. The i3DExcavatum was used to personalize prostheses
for 41 patients who underwent pectus excavatum surgical correction between 2007 and 2012. Regarding the anatomical
variations, the soft-tissue thicknesses external to the ribs show that both symmetric and asymmetric patients always have
asymmetric variations, by comparing the patients’ sides. It highlighted that the prosthesis bar should be modeled according
to each patient’s rib positions and dimensions. The average differences between the skin and costal line curvature lengths
were 84 ± 4 mm and 96 ± 11 mm, for male and female patients, respectively. On the other hand, the i3DExcavatum
ensured a smooth curvature of the surgical prosthesis and was capable of predicting and simulating a virtual shape and size
of the bar for asymmetric and symmetric patients. In conclusion, the i3DExcavatum allows preoperative personalization
according to the thoracic morphology of each patient. It reduces surgery time and minimizes the margin error introduced
by the manually bent bar, which only uses a template that copies the chest wall curvature.
; Rodrigues, Pedro L. 
