77231000146106: reconstructie van arteria carotis met interpositie van veneus transplantaat (verrichting)

SNOMED CT Concept\Procedure\...

\Surgical procedure (procedure)\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Operative procedure on artery of head and neck\Operation on carotid artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Operative procedure on artery of head and neck\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Cardiovascular surgical procedure\Cardiovascular system repair\Cardiovascular system reconstruction\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Cardiovascular surgical procedure\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Cardiovascular surgical procedure\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Cardiovascular surgical procedure\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Cardiovascular surgical procedure\Vascular surgery procedure\Operative procedure on artery of head and neck\Operation on carotid artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Cardiovascular surgical procedure\Vascular surgery procedure\Operative procedure on artery of head and neck\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Cardiovascular surgical procedure\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Cardiovascular surgical procedure\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Cardiovascular surgical procedure\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Surgical repair\Reconstruction procedure\Cardiovascular system reconstruction\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Surgical repair\Cardiovascular system repair\Cardiovascular system reconstruction\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Surgical repair\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Surgical repair\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Surgical procedure (procedure)\Surgical repair\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)

\Procedure by site\Procedure on body region (procedure)\Procedure on artery of head and neck\Operative procedure on artery of head and neck\Operation on carotid artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body region (procedure)\Procedure on artery of head and neck\Operative procedure on artery of head and neck\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Operative procedure on artery of head and neck\Operation on carotid artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Operative procedure on artery of head and neck\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Procedure on blood vessel\Procedure on artery\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Procedure on blood vessel\Procedure on artery\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Procedure on blood vessel\Procedure on artery\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Procedure on blood vessel\Procedure on artery\Procedure on artery of head and neck\Operative procedure on artery of head and neck\Operation on carotid artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Procedure on blood vessel\Procedure on artery\Procedure on artery of head and neck\Operative procedure on artery of head and neck\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Procedure on blood vessel\Vascular surgery procedure\Operative procedure on artery of head and neck\Operation on carotid artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Procedure on blood vessel\Vascular surgery procedure\Operative procedure on artery of head and neck\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Procedure on blood vessel\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Procedure on blood vessel\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on soft tissue\Procedure on blood vessel\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on organ\Procedure on blood vessel\Procedure on artery\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on organ\Procedure on blood vessel\Procedure on artery\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on organ\Procedure on blood vessel\Procedure on artery\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on organ\Procedure on blood vessel\Procedure on artery\Procedure on artery of head and neck\Operative procedure on artery of head and neck\Operation on carotid artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on organ\Procedure on blood vessel\Procedure on artery\Procedure on artery of head and neck\Operative procedure on artery of head and neck\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on organ\Procedure on blood vessel\Vascular surgery procedure\Operative procedure on artery of head and neck\Operation on carotid artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on organ\Procedure on blood vessel\Vascular surgery procedure\Operative procedure on artery of head and neck\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on organ\Procedure on blood vessel\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on organ\Procedure on blood vessel\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on organ\Procedure on blood vessel\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Procedure on blood vessel\Procedure on artery\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Procedure on blood vessel\Procedure on artery\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Procedure on blood vessel\Procedure on artery\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Procedure on blood vessel\Procedure on artery\Procedure on artery of head and neck\Operative procedure on artery of head and neck\Operation on carotid artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Procedure on blood vessel\Procedure on artery\Procedure on artery of head and neck\Operative procedure on artery of head and neck\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Procedure on blood vessel\Vascular surgery procedure\Operative procedure on artery of head and neck\Operation on carotid artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Procedure on blood vessel\Vascular surgery procedure\Operative procedure on artery of head and neck\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Procedure on blood vessel\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Procedure on blood vessel\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Procedure on blood vessel\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Cardiovascular surgical procedure\Cardiovascular system repair\Cardiovascular system reconstruction\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Cardiovascular surgical procedure\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Cardiovascular surgical procedure\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Cardiovascular surgical procedure\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Cardiovascular surgical procedure\Vascular surgery procedure\Operative procedure on artery of head and neck\Operation on carotid artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Cardiovascular surgical procedure\Vascular surgery procedure\Operative procedure on artery of head and neck\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Cardiovascular surgical procedure\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Cardiovascular surgical procedure\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by site\Procedure on body system\Procedure on cardiovascular system\Cardiovascular surgical procedure\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)

\Procedure by method\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Operative procedure on artery of head and neck\Operation on carotid artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Operative procedure on artery of head and neck\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Surgical procedure on soft tissue (procedure)\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Cardiovascular surgical procedure\Cardiovascular system repair\Cardiovascular system reconstruction\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Cardiovascular surgical procedure\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Cardiovascular surgical procedure\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Cardiovascular surgical procedure\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Cardiovascular surgical procedure\Vascular surgery procedure\Operative procedure on artery of head and neck\Operation on carotid artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Cardiovascular surgical procedure\Vascular surgery procedure\Operative procedure on artery of head and neck\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Cardiovascular surgical procedure\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Cardiovascular surgical procedure\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Cardiovascular surgical procedure\Vascular surgery procedure\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Surgical repair\Reconstruction procedure\Cardiovascular system reconstruction\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Surgical repair\Cardiovascular system repair\Cardiovascular system reconstruction\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Surgical repair\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Repair of artery using vein graft (procedure)\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Surgical repair\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Reconstruction of artery (procedure)\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)
\Procedure by method\Surgical repair\Cardiovascular system repair\Repair of blood vessel\Repair of artery (procedure)\Repair of artery of head and neck\Reconstruction of carotid artery\Reconstruction of carotid artery with venous interposition graft (procedure)

Status: current, Not sufficiently defined by necessary conditions definition status (core metadata concept). Date: 31-Mar 2021. Module: SNOMED CT Netherlands NRC maintained module (core metadata concept)

Descriptions:

Id Description Lang Type Status Case? Module

4265371000146119 Reconstruction of carotid artery with venous interposition graft (procedure) en Fully specified name Active Entire term case insensitive (core metadata concept) SNOMED CT Netherlands NRC maintained module (core metadata concept)

4265381000146117 Reconstruction of carotid artery with venous interposition graft en Synonym (core metadata concept) Active Entire term case insensitive (core metadata concept) SNOMED CT Netherlands NRC maintained module (core metadata concept)

12748531000146110 reconstructie van arteria carotis met interpositie van veneus transplantaat nl Synonym (core metadata concept) Active Entire term case insensitive (core metadata concept) SNOMED CT Netherlands NRC maintained module (core metadata concept)

12748541000146119 arterioplastiek van arteria carotis met interpositie van veneuze graft nl Synonym (core metadata concept) Active Entire term case insensitive (core metadata concept) SNOMED CT Netherlands NRC maintained module (core metadata concept)

12748551000146116 reconstructie van arteria carotis met interpositie van veneus transplantaat (verrichting) nl Fully specified name Active Entire term case insensitive (core metadata concept) SNOMED CT Netherlands NRC maintained module (core metadata concept)

Expanded Value Set

Outbound Relationships	Type	Target	Active	Characteristic	Refinability	Group	Values
Reconstruction of carotid artery with venous interposition graft (procedure)	Method	Reconstruction - action	true	Inferred relationship	Some	1
Reconstruction of carotid artery with venous interposition graft (procedure)	Using substance (attribute)	Vein graft material	true	Inferred relationship	Some	1
Reconstruction of carotid artery with venous interposition graft (procedure)	Procedure site - Direct (attribute)	Carotid artery structure	true	Inferred relationship	Some	1
Reconstruction of carotid artery with venous interposition graft (procedure)	Is a	Reconstruction of carotid artery	true	Inferred relationship	Some
Reconstruction of carotid artery with venous interposition graft (procedure)	Is a	Repair of artery using vein graft (procedure)	true	Inferred relationship	Some

Inbound Relationships

Type

Active

Source

Characteristic

Refinability

Group

This concept is not in any reference sets