Overview
ISO/PAS 7020:2023 - Sizing parameters of surgical valve prostheses: Requirements regarding the application of ISO 5840-2 - gives consensus-based, in vitro measurement guidance for sizing surgical heart valves (mechanical and stented bioprosthetic only). Developed by manufacturers, bioengineers and clinicians and supported by interlaboratory studies, the specification clarifies how to obtain and report key sizing parameters required by ISO 5840-2 so that labelling and comparisons between valve models are consistent and clinically useful.
Key topics and requirements
- Scope and exclusions: Applies to mechanical and stented bioprosthetic surgical valves; excludes sutureless valves, stentless valves and valved conduits.
- In vitro measurement methods: Specifies reproducible procedures for measuring sizing parameters for both flexible leaflet (bioprosthetic) and rigid (mechanical) valve designs.
- Defined sizing parameters (to be determined and reported):
- Inflow orifice diameter (ID-INFLOW) - measurement at the valve inflow (separate clarifications for flexible vs rigid designs).
- Effective orifice area / diameter (EOA / ID-EFFECTIVE) - derived from validated flow and pressure (or velocity) data using the in vitro steady-flow procedure; used to compute effective orifice diameter.
- Valve housing external diameter (OD-HOUSING) and external sewing ring diameter (ESRD / OD-SEWINGRING) - outer dimensions relevant to implantation and fit.
- Outer container labelling: Clarifies the additional sizing items that must appear on the unit box (diagrammatic and/or tabular) to support clinical size selection and device comparison.
- Terminology and precision: Provides standardized definitions (e.g., patient annulus diameter, intra-/supra-annular) and accuracy expectations informed by interlaboratory validation.
Applications and users
ISO/PAS 7020:2023 is practical for:
- Manufacturers - establishing standardized test procedures, producing consistent labelling, and demonstrating comparability across product lines.
- Regulatory and quality teams - harmonizing submission data and verification tests for valve sizing parameters.
- Independent test laboratories and bioengineers - conducting validated in vitro EOA and diameter measurements and interlaboratory studies.
- Clinicians and surgical teams - interpreting label data (inflow diameter, EOA) to reduce prosthesis–patient mismatch risk and support valve selection pre-operatively.
- Researchers and health technology assessors - comparing hemodynamic performance across devices using standardized metrics.
Related standards
- ISO 5840-1:2021 - Cardiac valve prostheses - Part 1: General requirements
- ISO 5840-2:2021 - Cardiac valve prostheses - Part 2: Surgically implanted heart valve substitutes
By standardizing how sizing parameters, EOA, and labelling are measured and reported, ISO/PAS 7020:2023 improves transparency, comparability and clinical decision-making for surgical valve prostheses.
Open preview (PDF)Sizing parameters of surgical valve prostheses: Requirements regarding the application of ISO 5840-2
