Systematic review of 3D-printed surgical devices for austere environments: an evaluation guideline.

BACKGROUND: Three-dimensional (3D) printing is a common manufacturing technique. It is being adopted to produce essential surgical equipment in austere settings around the world. However, the evaluation of these products remains inconsistent. This raises safety concerns and limits translation to clinical use. To address this, this systematic review aims to identify 3D-printed surgical devices intended for austere environments and examine their evaluation methodologies. The findings will inform the development of an evaluation framework that supports the design of patient-safe devices. METHODS: Medical and engineering bibliographic databases were searched to identify literature describing 3D-printed surgical devices for use in austere environments. Two independent blinded reviewers screened articles in two stages using abstracts and full texts. The review was conducted in accordance with PRISMA guidelines. In line with the EU Medical Device Regulation, device evaluations were categorised into manufacturing specifications, mechanical performance, sterilisation, biocompatibility, and usability. Reported methods of device evaluation were extracted and compared against the relevant published standards. RESULTS: 15 studies met the inclusion criteria. The austere environments included low-middle income countries, military settings, and space exploration. 13 out of 15 studies used Fused Deposition Modeling printers. All materials were thermoplastic. Printed equipment ranged from external fixators to surgical sets. The printing details were well reported. However, there was inconsistency in testing methods, resulting in data that is incomparable across the studies. 2 of 15 papers conducted mechanical testing for external fixators using American Society for Testing and Materials standards but used different parameters. 2 studies used self-developed mechanical testing protocols. 7 of 15 papers reported usability analysis using various methodologies. 3 of 15 papers described testing for sterilisation of the equipment, but only one paper evaluated its effect on the device. There was no biocompatibility testing. CONCLUSION: Despite the potential implications for patient safety, all 15 studies showed considerable variability in device evaluation methods. To address this, this review recommends adopting established standards from ISO, IEC and ASTM International. The proposed framework covers the key domains: manufacturing specifications, mechanical performance, sterilisation, biocompatibility and usability. Implementation of this structured approach may enhance standardisation and support the development of safer devices.