The most common anterior chest wall deformities are pectus excavatum (88%) and pectus carinatum (5%). Pectus excavatum is characterized by sternal depression with corresponding leftward displacement and rotation of the heart. Pectus carinatum exhibits a variety of chest wall protrusions and very diverse clinical manifestations. The cause of these conditions is thought to be abnormal elongation of the costal cartilages. Collagen, as a major structural component of rib cartilage, is implicated by genetic and histologic analysis.
Surgical correction technique and timing for congenital chest wall deformities in pediatric and adult patients varies from Institution to Institution. For adult patients affected by pectus excavatum or carinatum, the conventional surgical technique (Modified Ravitch technique) includes the implatation of a retro-sternal metal bar to secure the corrected sternal position. However, the implantation of the metal bar requires a second surgical step to remove the device after 7-12 months form the first operation.
The aim of the project is to develop a bioresorbable plate for Chest Wall deformities repair surgery and evaluate the clinical performance of the new surgical treatment based on the newly developed bioresorbable plate.
We intend to achieve our goal by accomplishing the following specific aims:
1. Provide design inputs derived from intra-operative biomechanical testing of strength to develop a chest wall deformities reabsorbable plate.
2. Produce the chest wall deformities reabsorbable implantable bar for the clinical study.
3. Assess the ability of the new chest wall deformities plate to reabsorb and to guarantee an effective corrective results.
The use of resorbable material for sternal support could provide many clinical benefits compared to the use of their non-resorbable counterparts. First of all, the implantation of resorbable supports for the sternum could avoid a longer hospitalization and a second surgical step required to remove the metal support.
Developing a resorbable bar is no simple. Although the use of reabsorbable implants is now firmly established in the medical devices market, in many instances the limitations that reabsorbable materials have served as a barrier to their application. Specifically, the supposed relatively low inherent strength of reabsorbable polymers has presented a roadblock to the new product design and a limit to their adoption in some medical field.
Stronger, more porous and lower profile resorbable implants are emerging for various clinical opportunities. Breakthroughs in processing technology, which overcome the limitations of current resorbable products, enable clinicians and developers of next generation chest wall products to create new reabsorbable implantable solutions, offering functional performance advantages and clinical outcome improvements.
In the treatment of the chest wall defotmity the use of a reabsorbable implantable bar may offer a compelling opportunity to improve patient care and clinical outcomes, reducing the number od procedures and consequently the costs. The reabsorbable implantable bar may post-operatively break down naturally, efficently supporting the healing process, leaving no foreign material in the body. No additional procedures are required for plate removal and, in case of having to undertake corrective surgery, it is possible to simply drill through the material. Also, unlike metal implants, reabsorbable implants don't interfere with imaging and radiotherapy.
The use of reabsorbable implants also presents other well-understood clinical benefits. Reabsorbable materials provide strength profile and density similar to those of the bone and can facilitate tissue regeneration at the surgical site, allowing gradual load transfer onto regenerating osseous tissue. By contrast, the load bearing capabilities afforded by metal implants, can lead to stress shielding, such that the metal implant bears the entire mechanical load, leading to a reduction in surrounding bone density, following implantation.
The safe and effective use of implantable medical devices built using reabsorbable biomaterials depends foremost on their biocompatibility. Full biocompatibility implies acceptance of a reabsorbable implant by the surrounding tissues and by the body as a whole. Biocompatible materials do not mechanically irritate the surrounding structures; they are not recognized as a threatening material eliciting a massive immunological response, and they do not elicit an abnormal cell growth with the potential to invade or spread to other parts of the body.
Over the coming years, it is likely that reabsorbable implants will form an ever-larger part of the implantable solutions portfolio for medical device companies.
However, in order to be a truly viable alternative to traditional implant materials, strength performance of reabsorbable materials need to be addressed.
New advanced processing methods that deliver this strength improvement, now offer an exciting platform for new product design, enabling the use of resorbable implants for even more indications, facilitating procedural innovation and the potential for improved clinical outcomes.