Pectus Excavatum Camouflage

Study Overview
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Brief Summary
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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 a resorbable frame to support the growth of cells. The substance used for the scaffold is resorbable, it's similar to the substance used for sutures and stitches, and it's already TGA approved for bone reconstruction of the skull. The implanted scaffold degrades over time, leaving the tissue in its place.

Detailed Description
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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 tecnhniques, 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 implanation. 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.

Official Title
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A Clinical Trial Evaluating Medical-Grade Polycaprolactone-PCL Pectus Scaffold Implantation With Autologous Fat Grafting for Pectus Excavatum Camouflage

Conditions
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Pectus Excavatum

Intervention / Treatment
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* Device: PCL Pectus Scaffold implantation and autologous fat grafting


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Pectus excavatum defect Patient aged ≥18 and <55 years (patients 55 years and over may still be eligible pending assessment by investigating team and documentation of rationale) Patient willing and able to comply with the study requirements. Patient is eligible to undergo MRI (i.e., no implanted incompatible metal or metal devices, no history of severe claustrophobia). Patient capable of providing valid informed consent. Exclusion Criteria: Patient with a known history of immunodeficiency including HIV, concomitant systemic corticosteroid therapy, chemotherapy, synchronous haematological malignancy or other cause for secondary/primary immunodeficiency. 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. Patient with unstable cardiac or respiratory function due to pectus excavatum or those requiring functional repair. Patient with body mass index (BMI) below 20 and above 30 kg/m2 (patients with a BMI above 30 kg/m2 may still be eligible pending assessment by investigating team and documentation of rationale). Patient with polycaprolactone (PCL) allergy Women who are currently pregnant or breast feeding, or who are planning to become pregnant within two years after the pectus excavatum camouflage surgery. Women of childbearing potential without an appropriate contraceptive method. Patient ineligible to undergo MRI. Patient with life expectancy < 36 months. Patient unable or unwilling to comply with the treatment protocol. Patient unwilling or unable to provide fully informed consent including but not limited to patients with intellectual or mental impairment.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 54 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Insertion of PCL Pectus scaffold<br>Insertion of a custom-made 3D printed medical-grade polycaprolactone (PCL) Pectus scaffold with autologous fat graft for pectus excavatum defect correction. | Device: PCL Pectus Scaffold implantation and autologous fat grafting<br>* A small incision is made in the chest and pre-sternal pocked is defined. Following this, an empty scaffold is implanted at the site of the defect with skin closed directly over it. At the same stage, autologous fat transfer will be performed, harvesting fat from available donor sites such as the thighs and abdomen - depending on scaffold volume and patient morphology. The area will be infiltrated with local anaesthetic tumescent fluid, liposuction performed, and fat transferred to syringes for filtration prior to injection into the scaffold. Fat will not be processed beyond simple filtration to separate liquid from fat to be injected. The scaffold provides structural stability to the chest during the infiltration of the tissue inside the scaffold.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Changes in adverse events, concomitant medications, vital signs, physical exam findings and cardiorespiratory function from baseline to the end of study visit. | Clinical safety will be assessed by documenting all adverse events regardless of whether they are related to the trial in an adverse events report form - described in detail in the case report form (CRF). These will be carefully evaluated by the principal investigator. | Assessed at 24-months post-surgery. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in (fat) volume % and soft tissue retention % from the time of surgery to the end of study visit using radiological and clinical assessments | Soft tissue retention will be evaluated by a senior radiologist utilising serial MRI imaging with assessment of soft tissue volume using a standardised segmentation protocol. Imaging will be taken at regular intervals in conjunction with clinical visits as defined by the protocol. | Assessed at 1-,3-,6-,12- and 24-months post-surgery with 2 years post surgery being the primary time-point. | 
| Change in cardiorespiratory function from baseline to 1 month after surgery | Pre-operative exercise tolerance testing to confirm their suitability for the trial. This will be repeated after complete recovery from the operation (usually after >4 weeks). Cardiorespiratory outcome will be assessed using baseline and post-operative cardiopulmonary exercise. Standard CPET protocol will be applied and validated by a physician. | Assessed at 1-month post-surgery | 
| Change in pain assessments from baseline to the end of study visit | Pain will be assessed with the numerical pain rating system from 0 (no pain at all) to 10 (worst imaginable pain) | Assessed at 1-month post-surgery | 
| Change in wound healing from the time of surgery to the end of study visit | Wound status will be assessed with the Holger Classification for wounds. | Assessed at 1-month post-surgery | 
| Change in patient quality of life as assessed by Quality of Life (QoL) questionnaires from baseline to the end of study visit | The Nuss questionnaire modified for adults (NQ-mA) and the 36-item Short Form Quality of Life (SF-36) questionnaire will be used to assess patient reported functional outcomes from the intervention. A combination of the NQ-mA and the SF-36 questionnaires provides a platform for comparison of the method proposed in this study against the current gold standard surgical management of pectus excavatum, as well as measuring the relative impact on health-related quality of live compared to interventions in other clinical scenarios. | Assessed at the 3-, 6-, 12- and 24-month clinical reviews |