Vascular Clips on CTA Chest: Clinical Significance and Interpretation
Vascular clips on a CTA chest scan typically indicate prior vascular or thoracic surgery, most commonly coronary artery bypass grafting (CABG), thoracic outlet decompression, or other vascular interventions that required vessel ligation or repair. 1
Types of Surgeries Associated with Vascular Clips
- Coronary artery bypass grafting (CABG) is one of the most common procedures where vascular clips are used to secure grafts and are subsequently visible on CTA 1, 2
- Thoracic outlet decompression surgery for thoracic outlet syndrome (TOS) often involves the use of vascular clips that may be visible on subsequent imaging 1
- Vascular repair following trauma, such as subclavian artery or vein repair, may require clips that are later visible on CTA 1
- Surgical interventions for aortic aneurysms or dissections may involve vascular clips that appear on subsequent imaging 1
Clinical Significance and Evaluation
- Vascular clips serve as important anatomical landmarks for radiologists and surgeons, helping to identify the location of previous interventions 1, 2
- In patients with history of CABG, vascular clips can help identify the course and location of bypass grafts, which is crucial for planning any future interventions 1, 2
- The presence of clips near the subclavian vessels may indicate prior thoracic outlet decompression surgery, which is important to note when evaluating for recurrent symptoms 1
- Clips may cause artifacts on CTA that can limit evaluation of adjacent structures, particularly with certain metallic compositions (cobalt-alloy clips create more artifacts than titanium-alloy clips) 3
Post-Surgical Evaluation Considerations
- When evaluating post-surgical patients with vascular clips, CTA with IV contrast is preferred over non-contrast CT as it provides assessment of vascular patency 1
- In post-CABG patients, CTA can assess graft patency with high accuracy (97.9% sensitivity, 100% specificity) even in the presence of surgical clips 4
- For patients with thoracic outlet syndrome who have undergone decompression surgery, CTA in neutral and elevated arm positions can evaluate for residual or recurrent vascular compression 1
- A filling defect adjacent to vascular clips in a pulmonary arterial stump after pneumonectomy is usually an in situ thrombus due to blood stasis rather than pathological embolism 5
Imaging Technique Optimization
- Sagittal reformations of CTA data provide better assessment of vascular structures than axial slices alone, with one study showing underestimation of stenosis in 43% of transverse CT scans but only 10% of sagittal reformations 1
- Volume-rendered images allow simultaneous analysis of bones and vascular structures, providing better visualization around clip artifacts 1, 6
- Subtraction techniques, such as orbital synchronized helical scan technique (OSHST), can reduce clip artifacts and improve visualization of adjacent vessels 3
- ECG-gated acquisitions may improve image quality in areas subject to cardiac motion, though this increases radiation exposure 1
Potential Complications to Assess
- CTA can identify post-surgical complications such as graft occlusion, anastomotic stenosis, or pseudoaneurysm formation near clip sites 1, 4
- In emergency settings, CTA can detect acute complications like graft bleeding, pericardial hematoma, or sternal instability that may require surgical revision 4
- Recurrent symptoms after thoracic outlet decompression surgery warrant CTA evaluation to assess for inadequate decompression or vascular complications 1
Understanding the significance of vascular clips on CTA chest helps guide appropriate clinical management and prevents unnecessary additional testing or interventions.