IHTSDO-1099 Aneurysm Naming Conventions

IHTSDO Content development – fast track (simple/single changes)
Non-ruptured aneurysm v Unruptured aneurysm v Aneurysm

Which should be used for the FSN?

Version Information

Document review

Statement of problem as requested or initially identified

Review of the hierarchy with parent concept of 432119003 | Aneurysm (disorder) |identified 4 different naming conventions to represent the presence of an aneurysm which has not ruptured:

The origin of the 'unruptured' and 'nonruptured' concepts would appear to be from current and previous editions of ICD where this nomenclature has been used to describe both congenital and non-congenital cerebral and arteriovenous aneurysms.
The use of 'unruptured' would appear to have originated from CTV3 and CMT CRS requests.
A search of PubMed reveals usage as follows:

This would suggest that 'Unruptured' is the most widely accepted alternative description.
From a strict Description Logic perspective, the meaning of 'Aneurysm' and 'Unruptured aneurysm' are different. The concept of 'Aneurysm' simple states that one exists and makes no assumptions about whether it is ruptured or not. 'Unruptured aneurysm' specifically states that an aneurysm is present, AND it has not ruptured.
From a clinical perspective, it would appear from the requests previously received and current content of SNOMED CT that the community of practice is content to accept that 'Aneurysm of xxx artery' means that an aneurysm is present and that it is currently unruptured.

Relevance to International edition

To provide a consistent fully specified naming convention for concepts which represent the presence of an aneurysm of a blood vessel which has not ruptured.
Concepts which negate the presence of a rupture cannot currently be sufficiently defined and would need to remain primitive which means that they cannot be used by the classifier to assign subtypes using our current classifier tools.

Related changes impacted by this content development request

None

Agreed scope statement

This discussion and proposed solution will apply to the concepts currently identified as subtypes of 432119003 | Aneurysm (disorder) | - currently 250 inferred concepts

Identify additional changes
None

Solution proposed
From a clinical perspective, it would appear from the requests previously received and current content of SNOMED CT that the community of practice is content to accept that 'Aneurysm of xxx artery' means that an aneurysm is present and that it is currently unruptured.
The literature review suggests that 'Unruptured aneurysm of xxx artery' is the most widely accepted alternative to 'Aneurysm of xxx artery'.
Therefore, the proposed solution is as follows:

• Where a concept exists that has an FSN of "Non-ruptured/Nonruptured/Unruptured aneurysm of xxx artery" inactivate these concepts with a reason of Duplicate and point to their 'aneurysm' equivalents where they exist or if they don't exist create new "Aneurysm of xxx artery" concepts.

• "Unruptured aneurysm" concepts are no longer accepted.

• In the editorial guidelines state that the use of 'Unruptured' as a synonym to these concepts is not allowed.

Stakeholder input
Stakeholder input from internal authors and Chief Terminologist.

Impact assessment
What errors will be corrected?

• Inconsistency of descriptions for the presence of an aneurysm which has not ruptured.

• Inability to sufficiently define concepts which have 'negation' as part of the concept.

What negative side-effects will (or might) occur?

• In a small number of concepts (approx. 18) users will not be able to find these using a keyword of non-ruptured, nonruptured or unruptured

Risk assessment
Identify risks of inaction as well as risks of making the change:

• Risks of inaction

  • Continued inconsistency of naming conventions for aneurysms which have not ruptured

  • Concepts which include negation may not be accessible to identification and extraction/analysis due to their primitive status

• Risks of making the change

  • Some users may initially believe that the aneurysm types inactivated are no longer available if they use the keyword of 'nonruptured'.

  • There may be an expectation by users that the status of aneurysms (i.e. unruptured) be expressly stated in the FSN

Approval process

Priority

☐Very high
☒High
☐Medium
☐Low

Specify the basis for the above priority assignment

Ordinarily the priority would be given as medium, however, this work forms a part of the QI 2019 project which has a high priority and therefore this assignment is based upon the assignment agreed for the parent project

Content editing
As per the QI 2019 project process

Details of content changes
A template will be produced which will specify the agreed modelling for all aneurysms - see

Manual quality check
Visual check of the FSNs for all subtypes of 432119003 | Aneurysm (disorder) |

Automated quality check
Conformance to the template

Publish to release branch
July 2019