JIRA Link:  

https://projects.jira.snomed.org/browse/IHTSDO-1125

https://projects.jira.snomed.org/browse/GC-1018

A subtask of QI << 782901001 |Insertion procedure (procedure)|
https://projects.jira.snomed.org/browse/QI-917 Flap procedures

Document Links:

Release used for analysis: January 2022

© Copyright 2021 International Health Terminology Standards Development Organisation.  All rights reserved.

This document is a publication of International Health Terminology Standards Development Organisation, trading as SNOMED International.  SNOMED International owns and maintains SNOMED CT®.

Any modification of this document (including without limitation the removal or modification of this notice) is prohibited without the express written permission of SNOMED International. This document may be subject to updates. Always use the latest version of this document published by SNOMED International. This can be viewed online and downloaded by following the links on the front page or cover of this document.

SNOMED®, SNOMED CT® and IHTSDO® are registered trademarks of International Health Terminology Standards Development Organisation. SNOMED CT® licensing information is available at http://snomed.org/licensing. For more information about SNOMED International and SNOMED International Membership, please refer to http://www.snomed.org or contact us at info@snomed.org.

1. Content Issue Summary 

a. Summary of issue 

• Inconsistency in flap procedures in SNOMED CT, both terming and modeling.

How does a flap differ from a graft? A flap is transferred with its blood supply intact, and a graft is a transfer of tissue without its own blood supply. Therefore, a graft relies on the recipient site for vascular perfusion whereas a flap has its own blood supply, or, in the case of a free flap then the blood vessels are 'reconnected' often microsurgically. Flap surgery is a subspecialty of plastic and reconstructive surgery.
Flaps can be classified in different ways based on:

• Donor site location and proximity to recipient site (local, distant)

• Method of transfer, for example, can be advanced, and/or pivotal (geometric) including rotation, transposition, and interpolation

• Flaps can be pedicled (transferred while still attached to their original blood supply) or free flaps (transferred unattached to their blood supply)

• Tissue composition/type of tissue to be transferred (eg, musculocutaneous, fasciocutaneous)

• The type of blood supply (eg, random, axial)

b. Related content projects and requests 

Freshdesk tickets from Australia:
https://ihtsdo.freshdesk.com/a/tickets/34643
https://ihtsdo.freshdesk.com/a/tickets/27452

https://request.ihtsdotools.org/#/requests/preview/735992

https://projects.jira.snomed.org/browse/GC-840

https://projects.jira.snomed.org/browse/GC-366

https://projects.jira.snomed.org/browse/IHTSDO-175

https://projects.jira.snomed.org/browse/SUBST-118

https://projects.jira.snomed.org/browse/GC-342

https://projects.jira.snomed.org/browse/IHTSDO-1188

https://projects.jira.snomed.org/browse/DLM-290

2. Analysis of Issue

Inconsistency across the whole flap procedure hierarchy. Many issues raised over many years by stakeholders both internally and externally including wrong inferences, inconsistent terming, redundant role groups being inherited (see 177429004 |Local rotation flap, myocutaneous (procedure)|), 304039000 |Skin flap operation (procedure)| is not a subtype of top flap procedure concept 74799003 |Flap graft (procedure)|, no model or guidance so different attributes being applied, conflation of flap with graft etc.

For << 256683004 |Flap (substance)| the subtypes are not correctly grouped and other issues see 3. Additional issues identified below.

Now QI has moved to procedures these issues can be addressed with the development of a model for flap procedures, and editorial guidance.

Number of concepts impacted:

Flap graft (procedure) SCTID: 74799003, Defined, Active. Descendants Count, Stated: 116 concepts, Inferred: 211 concepts.

Skin flap operation (procedure) SCTID: 304039000, Defined, Active. Descendants Count, Stated: 114 concepts, Inferred: 114 concepts.

256683004 |Flap (substance)| 353 sub-concepts.

3. Additional issues identified

• Top concept in the procedure hierarchy 74799003 |Flap graft (procedure)| is ambiguous as flap graft sounds like a technique not a procedure. A graft and a flap are not the same.

• << 74799003 |Flap graft (procedure)| and << 304039000 |Skin flap operation (procedure)| are not related: Skin flap operation (procedure) is not a subtype of Flap graft (procedure) and it should be.

• Incorrect synonym on 119829000 |Integumentary system transposition (procedure)| of 'Skin flap and skin graft operations'

• Both 363701004 |Direct substance (attribute)| and 424361007 |Using substance (attribute) currently used to model flap procedures.

• For Method the proposed target value is << 360032005 |Flap reconstruction - action (qualifier value)| but will need new subtypes (see Solution below).

• The proposal will involve substances from << 256683004 |Flap (substance)| but within this hierarchy the correct subtypes for each concept have not been assigned.

• High level groupers are distorting the sub-hierarchy in 256683004 |Flap (substance)| - Head and neck flap (substance)  - and others.

• Nonsensical substance groupers exist e.g. 256852000 |General flap (substance)|.

• Conflation of action and flap substance -736772001 |Rotation flap (substance)| and others.

• Conflation of graft and flap in substance hierarchy and  - e.g. 417257008 |Skin flap autograft (substance)|.

• Non-standard terming - e.g. 416744008 |Flap with osseous tissue only (substance)|.

• Many procedure terming variants exist: