Outpatient monitoring of Pectus Excavatum: a Neural Network-based approach

Analysis of chest wall elevation after the Nuss procedure using 3D body scanning technique in patients with pectus excavatum

PURPOSE

For the evaluation of the chest wall deformity, we adopted a non-invasive 3D body scanning system. The objective of this study is to evaluate surgical effect on the whole thorax using 3D scanning technique before and after Nuss procedure.

METHODS

We performed 3D body scanning using Structure Sensor (Occipital Inc, USA) in 11 symmetric patients (average age 13 ± 3.2) under general anesthesia before and after Nuss procedure. Using the scanned data, the improved chest wall was analyzed using 3D-Rugle (Medic Engineering, Japan) imaging software. Preoperative and postoperative 3D data were super-imposed and a thoracic elevating distance in the line of the axial and sagittal section through the deepest point was calculated. Pre- and postoperative external sternal angle (ESA) were calculated from the scanned data.

RESULTS

Mean thoracic elevation distance at the deepest point was 38.6 ± 6.1 mm and it was 28.4 ± 5.1 mm and 19.4 ± 4.9 mm at 4 cm and 8 cm cranial side, respectively. Average ESA improved from 3.9 ± 1.6 degrees to 15.0 ± 1.1 degrees after the operation.

CONCLUSION

Chest depression was effectively elevated 39 mm at the deepest point after Nuss procedure. An indirect elevation effect by pectus bars was found on the wide area of the anterior chest.

Handheld Optical System for Pectus Excavatum Assessment

Disruptive 3D technologies, such as reverse engineering (RE) and additive manufacturing (AM), when applied in the medical field enable the development of new methods for personalized and non-invasive treatments. When referring to the monitoring of pectus excavatum, one of the most common thoracic malformations, 3D acquisition of the patient chest proved to be a straightforward method for assessing and measuring chest deformation. Unfortunately, such systems are usually available in a dedicated facility, can be operated only by specialized doctors with the support of engineers and can be used only with patients on site. It is therefore impossible to perform any routine check-up when the patient is unable to reach the outpatient clinic. The COVID19 pandemic situation has placed even greater restrictions on patient mobility, worsening this problem. To deal with this issue, a new low-cost portable optical scanner for monitoring pectus excavatum is proposed in this work. The scanner, named Thor 2.0, allows a remote diagnostic approach, offering the possibility to perform routine check-ups telematically. Usability tests confirmed the user-friendly nature of the devised system. The instrument was used at the Meyer Children’s Hospital (Florence, Italy) chest-malformations center to treat PE patients. The performed measurements proved to be in line with the current state of the art.