Related Experiment Video
Updated: Jul 8, 2026
Permanent Cerebral Vessel Occlusion via Double Ligature and Transection
Published on: July 21, 2013
Endangered cerebral blood supply after closure of left subclavian artery: postmortem and clinical imaging studies
Hannu Manninen1, Harri Tulla, Ritva Vanninen
1Department of Radiology, Diagnostic Medical Imaging Centre, Kuopio University Hospital and Kuopio University, Kuopio, Finland. hannu.manninen@kuh.fi
Insights
Closing the left subclavian artery (LSA) during thoracic endovascular repair poses a risk for posterior cerebral circulation insufficiency. Careful pre-procedural imaging of the right vertebral artery and posterior communicating arteries is crucial to identify at-risk patients.
Area of Science:
- Vascular Surgery
- Neuroendovascular Interventions
- Cerebrovascular Anatomy
Background:
- Endovascular stent-graft repair for thoracic aortic disease frequently involves coverage of the left subclavian artery (LSA).
- Potential hemodynamic consequences of LSA coverage without revascularization require assessment.
- Critical collateral pathways for posterior cerebral circulation include the right vertebral artery and posterior communicating arteries (PComA).
Purpose of the Study:
- To evaluate the hemodynamic risks associated with LSA coverage during endovascular thoracic aortic repair.
- To identify anatomical variations that may compromise posterior cerebral circulation after LSA coverage.
- To determine the incidence of anatomical factors predisposing to neurological complications.
Main Methods:
- Postmortem anatomical study of 92 deceased individuals.
- Assessment of cerebral artery anatomy using angiography and silicone casts.
- Review of clinical craniocervical CT and MR angiographies for anatomical variations.
Main Results:
- A substantial risk for neurological complications was identified in 5.4% of cases due to a narrow right vertebral artery (<2 mm) and incomplete PComA.
- An additional 3.3% of cases presented with a hypoplastic right vertebral artery, indicating a possible risk.
- Review of clinical imaging revealed other anatomical variants of the Circle of Willis associated with increased risk.
Conclusions:
- Insufficiency of posterior cerebral circulation due to anatomical factors after LSA coverage is infrequent but significant.
- Mandatory pre-procedural imaging of the right vertebral artery up to the basilar artery is recommended.
- If the right vertebral artery is hypoplastic, imaging of the PComAs is necessary to assess collateral flow and prevent complications.
Background:
The aim of this study was to assess hemodynamic consequences of increasingly common coverage of the left subclavian artery (LSA) during endovascular stent-graft repair for thoracic aortic disease without surgical revascularization. We considered that critical arteries to examine are the right vertebral artery and posterior communicating arteries (PComA) because their simultaneous insufficiency would drastically endanger posterior cerebral circulation. The existence and the diameters of these arteries were studied in a postmortem anatomic study with review of clinical craniocervical computed tomographic (CT) and magnetic resonance (MR) angiographies.
Methods:
The anatomic material was collected as a part of forensic medicine autopsies. The anatomy of the cerebral arteries of 92 deceased was assessed by angiography and permanent silicone casts.
Results:
In five individuals (5.4%) the risk for acute neurological complication after "unprotected" closure of the LSA was estimated to be "substantial" because the diameter of the right vertebral artery above the posterior inferior cerebellar artery was less than 2 mm and was associated with incomplete PComA and in three additional cases (3.3%) with only hypoplastic right vertebral artery, as "possible." Review of a clinical teaching file of MR and CT angiographies with anatomic variations and abnormalities of the circle of Willis identified, also, other variants with increased risk.
Conclusions:
When the LSA is closed, insufficient posterior cerebral circulation due to anatomic reasons occurs relatively infrequently, but in order to avoid the debilitating complications in these cases, careful imaging of the right vertebral artery up to the basilar artery is mandatory, and if proven hypoplastic, imaging of PComAs is necessary.
