Cardiovascular clamping procedures can cause tissue traumatization, leading to serious adverse events interrupting blood flow and causing life-threatening hemorrhage. The aim of the study is to evaluate the properties of 3D-printed, high-elasticity elastomeric materials—BioMed Flex 50A and 80A (Formlabs Inc., Sommerville, MA, USA)—in terms of their suitability for the fabrication of atraumatic inserts used for surgical clamping instruments. To show the importance of the elaboration of the new atraumatic materials, finite element simulations of blood vessel compression by a surgical tool were validated experimentally with porcine vessels, and histopathology assessed the tissue response. These results confirm that excessive clamping forces can cause vessel wall stratification and rupture. Specimens BioMed Flex 50A and 80A underwent surface, mechanical, and biological testing, including topography, wettability, acoustic microscopy for structural voids, cytotoxicity with human dermal fibroblasts, pro-inflammatory marker analysis, and bacterial biofilm assessment. The results of the testing of the 3D-printed BioMed Flex 50A and 80A materials show good potential for applications in safe atraumatic surgical instruments. Further research may include the possibilities to develop 3D-printed metamaterials with pressure adapting properties.

The purpose of this pilot study was to evaluate how material compliance, surface geometry and internal architecture of atraumatic clamping inserts influence vascular tissue injury. The main research question was whether metamaterial-inspired inserts can reduce vessel trauma during compression. Inserts were fabricated using additive manufacturing from two medical grade elastomers with different stiffness levels. All samples had identical external dimensions but differed in surface geometry – either smooth or grooved – and in internal architecture, including solid cores and channel-based structures. Porcine aorta specimens were compressed under controlled physiological conditions for a clinically relevant duration. Tissue damage was assessed qualitatively using histological analysis and graded according to a standardized injury scale. Surface topography was examined using digital microscopy. Experimental findings were supported by nonlinear numerical simulations of vessel compression to evaluate stress and strain distributions. Inserts manufactured from the more compliant elastomer generally produced lower grades of vascular injury than stiffer inserts. In the BioMed 80A group, deeply structured surface variants were generally associated with increased tissue damage. Numerical simulations supported the experimental findings, suggesting that contact surface geometry was the primary factor influencing stress concentrations in the vessel wall, with material stiffness playing a secondary role. The results suggest that atraumatic performance of metamaterial-inspired clamping inserts appears to be influenced by the combined effects of surface geometry, internal architecture and material compliance. Compliant metamaterial-inspired inserts with optimized internal channel structures show promise for minimizing vascular tissue trauma during surgical procedures. However, these preliminary findings require further quantitative validation in larger studies.

Stress-corrosion cracking (SCC) of buried gas pipelines has remained a global problem for over 50 years. As pipelines age, new SCC cases emerge, including in welded joints. Improving ductility in these joints is one way to enhance SCC resistance. A welded joint of X70 steel was made using single-arc submerged arc welding (OK10.74, Sv-08GNMA wire). SCC behavior was studied under cathodic polarization in NS4 solution using ANSYS modeling, slow strain rate tests, and scanning electron microscopy (SEM). Results showed that SCC in joints without a stress concentrator occurs along the base metal at a polarization potential of -1.050 V (vs. Ag/AgCl), indicating high weld quality and resistance to brittle fracture. Finite element modeling revealed stress concentration in the base metal during rupture. SEM analysis confirmed increased brittle fracture zones in these joints. With a V-shaped stress concentrator, SCC propagated along the weld, avoiding the heat-affected zone and base metal, which highlights the joint’s ductility. Numerical modeling showed maximum deformation beneath the notch, where fracture initiates. These findings demonstrate that ductile welded joints can effectively resist SCC, and stress concentrators significantly influence crack propagation paths. The study emphasizes the importance of weld quality and joint design in maintaining pipeline integrity under corrosive conditions.