(84 days)
The AeroForm® Tissue Expander System is used for soft tissue expansion in breast reconstruction following mastectorny. for the treatment of underdeveloped breasts, and for the treatment of soft tissue deformities in the breast.
The AeroForm® Tissue Expander is intended for temporary subcutaneous or submuscular implantation and is not intended for use beyond 6 months.
The AeroForm Tissue Expander System (AeroForm System) is a sterile temporary implant for breast reconstruction and is comprised of a sterile, implantable tissue expander), a remote control (Controller), and a Master Key. The AeroForm Tissue Expander is a comprised of an outer textured silicone shell, an inner gas barrier (bag), with an internal reservoir of compressed Carbon Dioxide (CO2) gas, which is released within the Expander by using the remote control (Controller), resulting in gradual expansion of the Expander. In a typical, twostage breast reconstruction, a tissue expander device is placed under the pectoralis major muscle and remaining skin following a mastectomy procedure. The Expander is gradually expanded over time through the release of carbon dioxide, causing the overlying skin and muscle to stretch. When adequate tissue coverage is achieved, the expansion device is removed and replaced with a breast implant.
This document describes the regulatory submission for the AeroForm Tissue Expander System. It is not an AI/ML device, so many of the requested fields are not applicable. I will fill in the applicable information about the device's acceptance criteria and the studies performed.
1. A table of acceptance criteria and the reported device performance
| Test | Acceptance Criteria | Reported Device Performance |
|---|---|---|
| Mechanical Performance Testing | ||
| Endurance / Stress Tests (cycle, impact, elongation, sustained pressure) | Meet requirements of ASTM F1441 and pre-determined criteria | All results met pre-determined acceptance criteria and ASTM standard requirements |
| Break Force | Meet requirements of ASTM F1441 and pre-determined criteria | All results met pre-determined acceptance criteria |
| Fused or Adhered Joint Testing | Meet requirements of ASTM F1441 and pre-determined criteria | All results met pre-determined acceptance criteria |
| Overexpansion | Meet requirements of ASTM F1441 and pre-determined criteria | All results met pre-determined acceptance criteria |
| Sterilization and Package Integrity Testing | Package remains intact after climatic conditioning, gross leak, and seal strength testing | Demonstrates package remains intact |
| Software Testing | Compliant with EN 62304 and applicable US FDA guidance documents | Unit, System, and Regression Testing performed, compliant |
| Biocompatibility Testing (EN ISO 10993) | All tests (Genotoxicity, Cytotoxicity, Sensitization, Irritation, Acute Systemic Toxicity, Sub-chronic Toxicity, Chronic Toxicity, Implantation) pass requirements | All tests passed the requirements of EN ISO 10993, demonstrating biological safety |
| Electrical Safety & EMC Testing | Meet applicable standards | Performed (details not provided in summary) |
| Shelf Life Testing | Device integrity maintained over specified shelf life | Performed (details not provided in summary) |
| Human Factors Evaluation | Device is safe and effective for intended users and use environments | Performed (details not provided in summary) |
2. Sample sized used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
The document primarily describes pre-clinical and verification/validation testing for a physical medical device (tissue expander). There is no mention of a "test set" in the context of an AI/ML device employing a dataset for evaluation. The "test set" for mechanical and biological performance refers to the physical devices and materials tested. The provenance of these tests are standard laboratory and engineering tests; no data provenance from patient populations is mentioned for these specific tests in the provided text.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts (e.g. radiologist with 10 years of experience)
Not applicable. This is not an AI/ML device relying on expert-annotated ground truth for a test set. The "ground truth" for the performance attributes is established through recognized international standards (e.g., ASTM F1441, EN ISO 10993) and internal engineering specifications, executed and assessed by qualified engineering and scientific personnel.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not applicable. As this is not an AI/ML device, there is no expert adjudication of outputs from an algorithm. Results are assessed against pre-defined quantitative and qualitative acceptance criteria from recognized standards and internal specifications.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
Not applicable. This is not an AI/ML device, and no MRMC study with human readers or AI assistance was conducted or mentioned.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
Not applicable. This is a physical medical device (tissue expander) with a software component for control; it is not a standalone algorithm. The software testing mentioned is for the functionality and compliance of the embedded software, not for a diagnostic or predictive AI algorithm.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
The "ground truth" for this device's performance evaluation lies in:
- Mechanical Integrity/Performance: Compliance with ASTM F1441 standards and internal engineering design specifications.
- Biocompatibility: Conformance to EN ISO 10993 standards.
- Software: Compliance with EN 62304 and FDA guidance for software development (functional correctness, safety).
- Sterilization/Shelf Life: Compliance with applicable standards for sterility, package integrity, and stability over time.
These are established through standardized testing methodologies rather than expert consensus on medical images or pathology.
8. The sample size for the training set
Not applicable. This is not an AI/ML device that requires a training set.
9. How the ground truth for the training set was established
Not applicable. This is not an AI/ML device that requires a training set.
§ 878.3510 Carbon dioxide gas controlled tissue expander.
(a)
Identification. A carbon dioxide gas controlled tissue expander is a prescription device intended for temporary subcutaneous or submuscular implantation to stretch the skin for surgical applications, specifically to develop surgical flaps and additional tissue coverage. The device is made of an inflatable elastomer shell and is filled with carbon dioxide gas. The device utilizes a remote controller to administer doses of carbon dioxide gas from an implanted canister inside the device.(b)
Classification. Class II (special controls). The special controls for this device are:(1) In-vivo performance testing must be conducted to obtain the adverse event profile associated with use, and demonstrate that the device performs as intended under anticipated conditions of use.
(2) The patient-contacting components of the device must be demonstrated to be biocompatible.
(3) Performance data must demonstrate the sterility of patient-contacting components of the device.
(4) Non-clinical performance testing must demonstrate that the device performs as intended under anticipated conditions of use. The following performance characteristics must be tested:
(i) Cycle testing of expander showing that there are no leaks or tears after repeated cycling;
(ii) Mechanical assessment of implanted carbon dioxide (CO
2 ) canister including high impact testing;(iii) Leak testing of expander showing that device does not leak CO
2 ;(iv) Assessment of gas permeability during expansion and after full expansion; and
(v) Mechanical assessment of expander (tensile set, breaking force, shell joint test, and fused or adhered joint testing).
(5) Performance data must be provided to demonstrate the electromagnetic compatibility, electrical safety, and wireless compatibility of the device.
(6) Software verification, validation, and hazard analysis must be performed.
(7) Performance data must support shelf life by demonstrating continued sterility of the device or the sterile components, package integrity, and device functionality over the identified shelf life.
(8) Human factors testing and analysis must validate that the device design and labeling are sufficient for the end user.
(9) Physician labeling must include:
(i) The operating parameters, name, and model number of the indicated external dosage controller;
(ii) Information on how the device operates and the typical course of treatment;
(iii) Information on the population for which the device has been demonstrated to be effective;
(iv) A detailed summary of the device technical parameters; and
(v) Provisions for choosing an appropriate size implant that would be exchanged for the tissue expander.
(10) Patient labeling must include:
(i) Warnings, precautions, and contraindications, and adverse events/complications;
(ii) Information on how the device operates and the typical course of treatment;
(iii) The probable risks and benefits associated with the use of the device;
(iv) Post-operative care instructions; and
(v) Alternative treatments.
(11) Patient training must include instructions for device use, when it may be necessary to contact a physician, and cautionary measures to take when the device is implanted.