Elastic stable chest repair and its hybrid variants in 86 patients with pectus excavatum

Current Concepts in the Etiology and Pathogenesis of Pectus Excavatum in Humans-A Systematic Review

Pectus excavatum (PE) is the most common deformity of the chest wall and is characterized by the posterior depression of the sternum and the lower costal cartilages. To date, the etiology of PE in humans remains enigmatic. Several etiologic hypotheses have been proposed over the past two centuries. However, most of them have been scientifically dismissed and now have only historic value. In this systematic review, we assess scientific publications of the past two centuries addressing the issue of the origin of PE in humans. We present and discuss the histologic, genetic, biomechanical, and experimental scientific achievements that contributed to the clarification of its etiology and pathogenesis. With no clear consensus over the exact mechanism, most recent studies agree that the primordial defect leading the deformation of the anterior chest wall in PE is related to the costal hyaline cartilage structure and function. Further studies on this subject must be carried out. Genetic studies seem to be the most promising way to understand the exact mechanism of PE's origin and pathogenesis.

[Funnel Chest Corrective Surgery with the Aid of a 3D Reconstruction of the Bony Thorax for Preoperative Adjustment of the Metal Bar]

BACKGROUND

Funnel chest is a congenital deformity of the thorax in which the sternum and the adjacent ribs form a funnel towards the spine. As the pathogenesis has not yet been clearly clarified, there are different therapeutic approaches. These range from conservative measures and minimally invasive surgery to open corrective surgery. The patients suffer from aesthetic impairment, as well as cardiopulmonary restrictions due to the narrowing of the mediastinal space. The indication for funnel chest correction surgery is therefore justified by functional and aesthetic reasons.

PATIENTS

We report a 23-year-old male patient who presented with subjectively impairing and objectively moderate funnel chest. A chest CT scan was performed preoperatively. The sternovertebral distance was 8 cm, the transverse thoracic diameter 28,9 cm (Haller's index 3.6). The preoperative pulmonary function test showed a slight restriction, the otherwise healthy patient described shortness of breath with greater exertion. The indication for funnel chest correction surgery was made. The operation was performed using a combined surgical technique: sternotomy and cartilage wedge resection according to Brunner/Grob and implantation of a metal bar without lateral antirotation plate. The most time-consuming step of the operation is the intraoperative adjustment of the metal bar. Therefore, in advance of the operation, we used a 3D printer to prepare a 3D reconstruction of the bony thorax with the help of the thorax CT scan. The metal bar was then bent and fitted to the thorax print and implanted during surgery. This allowed us to shorten the operation time by at least 15 min.

RESULTS

The postoperative follow-up examinations showed a clearly erect funnel and a satisfactory aesthetic result. The metal bar explantation took place, as planned, 7 months after implantation. The postoperative CT scan now showed a Haller's index of 3.25, the pulmonary function test showed improved results. Subjectively, the patient was always symptom-free.

CONCLUSION

The preparation of medical implants with 3D patient models as templates helps to save operation time. The practicability has not yet been established, as the creation of a 3D model of the bony thorax is associated with a different approach. With the increasing digitisation of the medical world, however, it is conceivable that the creation of digital and real 3D models will become easier and cheaper in the future.