The clinical study is testing a new treatment for pectus excavatum called "custom-made 3D printed scaffold-based soft tissue reconstruction". The new method uses a combination of the patients own adipocytes (fat cells) with a 3D printed scaffold (PCL Pectus Scaffold) to support soft tissue regeneration in the patient's chest using the body's natural healing processes.

The implanted scaffold acts as absorbable frame to support the growth of cells. The substance used for the scaffold is absorbable, it's similar to the substance used for sutures and stitches, and it's already Therapeutic Goods Administration (TGA) approved for bone reconstruction of the skull. The implanted scaffold degrades over time, leaving the tissue in its place.

A 3D printed scaffold made of medical grade polycaprolactone is planned to be implanted to correct pectus excavatum defects. First the patient will be thoroughly evaluated with history taking, examination and medical imaging to determine whether they are suitable for implantation. Imaging will take place as part of the work-up for the trial in the form of a CT scan and MRI. If the patient is deemed suitable for the trial, a custom-made scaffold for the patient chest wall defect is designed based on the medical imaging attained previously. This scaffold is then manufactured and sterilised, before being implanted.

The implantation surgery will be done at a tertiary teaching hospital by an experienced plastic and reconstructive surgeon. During the implantation procedure, the patient's own fat cells are harvested through simple liposuction techniques, usually from the abdomen and thighs depending on the availability of the tissue. The fat cells that are harvested are then injected into the implanted scaffold at the time of implantation. The total length of procedure is estimated to take 1 hour.

The patients progress will be evaluated daily after the procedure while they are in hospital with clinical assessment of the wounds and overall status. On discharge a number of surveys will be performed to document the progress at regular intervals, as well as recurrent MRI studies.

The effectiveness, complications and side-effects will be monitored for up to two years.

All appointments and clinical assessment will be documented in the electronic patient medical record as well as a secure de-identified trial database.

Inclusion Criteria:

1. Pectus excavatum defect
2. Patient aged ≥18 and <55 years (patients 55 years and over may still be eligible pending assessment by investigating team and documentation of rationale)
3. Patient willing and able to comply with the study requirements.
4. Patient is eligible to undergo MRI (i.e., no implanted incompatible metal or metal devices, no history of severe claustrophobia).
5. Patient capable of providing valid informed consent.

Exclusion Criteria:

1. Patient with a known history of immunodeficiency including HIV, concomitant systemic corticosteroid therapy, chemotherapy, synchronous haematological malignancy or other cause for secondary/primary immunodeficiency.
2. Patient with known severe concurrent or inter-current illness including cardiovascular, respiratory or immunological illness, psychiatric disorders, alcohol or chemical dependence, possible allergies that would, in the opinion of the Principal Investigator, compromise their safety or compliance or interfere with interpretation of study results.
3. Patient with unstable cardiac or respiratory function due to pectus excavatum or those requiring functional repair.
4. Patients with Body Mass Index (BMI) below 18.5 kg/m2 and above 30 kg/m2. NB: Patients with BMI up to 10% higher than the upper limit (up to 33 kg/m2) can be still enrolled if the treating surgeon confirms that BMI is not associated with any kind of pathology.
5. Patient with polycaprolactone (PCL) allergy
6. Women who are currently pregnant or breast feeding, or who are planning to become pregnant within two years after the pectus excavatum camouflage surgery.
7. Women of childbearing potential without an appropriate contraceptive method.
8. Patient with life expectancy < 36 months.