Imaging Pearls ❯ Vascular ❯ Thoracic aorta surgery
|
-- OR -- |
|
- “TRO was associated with slightly higher yield of PE and AD, specifically in the emergency department. This benefit comes with higher nondiagnostic image quality, radiation, and contrast doses. Although TRO may be of value in selected patients, its indiscriminate use is not warranted. The appropriate use of TRO needs to be further defined.”
Triple Rule Out Versus Coronary CT Angiography in Patients With Acute Chest Pain Burris II, AC et al. J Am Coll Cardiol Img 2015;8:817–25
- “In the surgical context, the term pseudoaneurym is applied to any extravascular or extragraft blood-perfused space typically arising from a site of anastomosis, can- nulation, or arteriotomy, arising from an artery, graft, or the heart (for example, the infravalvular region of the left ventricular outflow tract).”
Pre- and Postoperative Imaging of the Aortic Root Hanneman K et al. RadioGraphics 2016; 36:19-37 - “A pseudoaneurysm is defined as a blood-filled space beyond the expected contours of an artery due to a partial or complete breach of the arterial wall, with a persistent communication to the bloodstream. Pathologically, a pseudoaneurysm may be contained by some, but not all, layers of the original arterial wall (for example, a traumatic aortic pseudoaneurysm may be contained by an intact adventitial layer), or it may be contained by surrounding tissues alone.”
Pre- and Postoperative Imaging of the Aortic Root Hanneman K et al. RadioGraphics 2016; 36:19-37 - “Hyperattenuating felt pledgets may be mistaken for a pseudoaneurysm on contrast-enhanced CT angiograms, warranting careful evaluation of non- enhanced images to confirm the presence of the high-attenuation (polytetrafluoroethylene) surgical material. In comparison, pseudoaneurysms are usually iso- or hypoattenuating relative to surrounding tissue, and isoattenuating with the blood pool, on noncontrast CT images.”
Pre- and Postoperative Imaging of the Aortic Root Hanneman K et al. RadioGraphics 2016; 36:19-37
- Open Aortic Repair
Native aorta replaced by graft material
Imaging features:
- Graft material hyperdense on CT
- Felt used at anastomosis also hyperdense
- Mild kinking common
- Tubular appearance
- Perigraft fluid common; may persist but should not increase - Aortic Root Repair
Must know surgical procedure
- Valve may be replaced (composite grafts = valve + root)
- coronary reimplantation (most common) or bypass
Interposition graft
- Preferred, most common
Inclusion graft
- Native root wrapped around graft
- Fluid expected between graft and excluded native root - Aortic Arch Repair
Elephant trunk repair
- Complex , two stage procedure for arch and descending thoracic aneurysms
Stage I
- Repair of arch and proximal descending thoracic aorta
- At end of first stage, may have free floating ends of graft in descending thoracic aorta
- Can be mistaken for dissection
Stage II
- Descending thoracic repair completed
- Free floating ends fixed by additional graft anastomosis or an endovascular stent - Normal post-op findings
Perigraft fluid
- Usually decreases over time
- In some cases may persist indefinitely
- Should not increase or contain new hyperdense material (indicates leak)
Air
- Should not be seen >3 months after surgery
- Should not increase
Surgical material
- Felt used at anastomoses and aortotomy sites
- Hyperintense on non-contrast images - Open Repair Complications
- Pseudoaneurysm, infection, dehissence
- Coronary ostial aneurysms
- Graft thrombosis
- Aortoenteric fistula - Aortoenteric fistula
- Usually secondary (post-operative) with communication between aneurysm sac and duodenum
- Gas in the aneurysm sac
- Fluid and inflammatory stranding
- Bowel tethered to aorta
- Thoracic Aortic PSA
- Ascending aorta most common location
- Sequela of cardiac surgery
- Surgically manipulated locations
- proximal valve graft anastomosis
- distal aortic anastomosis
- coronary button reimplantation
- vein graft anastomosis
- Complications: SVC syndrome, rupture - Extensive Aortic Pathology
- Pathology that multiple aortic segments
- Necessitates staged repair
- Stage 1:
- Ascending aortic graft
- Elephant trunk prosthesis arch/proximal descending thoracic aorta
- Stage 2:
- Descending aorta +/- abdominal aorta repair - Elephant Trunk
- Protects the diseased descending thoracic aorta until the second segment of the surgery can be performed
- Used as part of the descending aortic graft at second surgery
- Enables second surgery to be performed distal to first surgical location, in unaltered tissue planes - Post Surgical Repair
- Surgical grafts dilate over time
- Rate depends on the graft material
- ePTFE vs polyester
- At 6 years, dilatation ranges between 20-30%
- ePTFE exhibits lowest degree of dilatation
- Dilatation does not result in graft failure - Post Surgical Repair
- Grafts lose strength over time, owing to polyester degradation.
- 31.4% lost at 10 years
- 100% lost at 25-39 years - “Aortic intramural hematoma is among the spectrum of pathologies that comprises acute aortic syndrome and carries a risk of progression to aortic dissection, aneurysm, rupture, and other complications. Evaluation by CT can identify imaging features associated with higher risk of complications. Ulcer-like projections, enlarged aortic diameter, increased hematoma thickness, and Stanford type A classification are associated with progression to complications. The significance of intramural blood pools within the hematoma and associated pleural/pericardial effusions is less certain. Detailed evaluation of intramural hematoma with CT can provide critical prognostic information with implications for patient management.”
Aortic intramural hematoma: Review of high-risk imaging features
Kruse MJ, Johnson PJ, Fishman EK, Zimmerman SL
J Cardiovasc Comput Tomogr. 2013 Jul-Aug;7(4):267-72 - “Aortic intramural hematoma is among the spectrum of pathologies that comprises acute aortic syndrome and carries a risk of progression to aortic dissection, aneurysm, rupture, and other complications. Evaluation by CT can identify imaging features associated with higher risk of complications. Ulcer-like projections, enlarged aortic diameter, increased hematoma thickness, and Stanford type A classification are associated with progression to complications.”
Aortic intramural hematoma: Review of high-risk imaging features
Kruse MJ, Johnson PJ, Fishman EK, Zimmerman SL
J Cardiovasc Comput Tomogr. 2013 Jul-Aug;7(4):267-72 - “ Detailed evaluation of intramural hematoma with CT can provide critical prognostic information with implications for patient management.”
Aortic intramural hematoma: Review of high-risk imaging features
Kruse MJ, Johnson PJ, Fishman EK, Zimmerman SL
J Cardiovasc Comput Tomogr. 2013 Jul-Aug;7(4):267-72