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    Surgical repair of aorta may be required for aortic aneurysms, aortic dissections or congenital malformations such as coarctation.1 Grafts may be introduced during open or endovascular procedures to prevent rupture of an expanding vascular aneurysm, usually in the abdominal aorta. Specimens received in the laboratory often consist only of thrombus removed from the blood vessel.2 However, tissue from the vessel wall may be submitted for investigation of degenerative or inflammatory conditions, connective tissue disease and occasionally tumour.1-3

    Record the patient identifying information and any clinical information supplied together with the specimen description as designated on the container. See overview page for more detail on identification principles.

    • No
      • Non-routine fixation (not formalin), describe.
    • Yes
      • Special studies required, describe.
      • Ensure samples are taken prior to fixation.
    • Not performed
    • Performed, describe type and result

    See general information for more detail on specimen handling procedures.

    Inspect the specimen and dictate a macroscopic description.

    External Inspection

    Orientate and identify the anatomical features of the specimen.

    Record additional orientation or designation provided by operating clinician:

    • Absent
    • Present
      • Method of designation (e.g. suture, incision)
      • Featured denoted

    Photograph the intact specimen if required.2

    Describe the following features of the specimen:


    Record as stated by the clinican

    • Abdominal aortic aneurysm (AAA) repair
    • Ascending aortic aneurysm
    • Thoracic aortic aneurysm
    • Other, describe

    Specimen integrity

    • Intact
    • Disrupted/fragmented

    Anatomical components (more than one may apply) and specimen dimensions (mm)

    Describe and measure the anatomical components present.

    • Intact
      • Three dimensions, cross-sectional diameter x height x thickness
    • Fragments
      • Number of pieces1
      • Total specimen, in three dimensions1
    • ​Other, specify


    Describe the overall shape if intact.

    • Normal
    • Dilated
      • Fusiform
      • Saccular


    Section the specimen perpendicularly to the luminal surface.1

    Internal Inspection

    Describe the appearance of the luminal surface including the following items:

    Atherosclerotic plaque(s)

    • Absent
    • Present
      • Number
      • Size in three dimensions (mm)

    Tree barking (thickened, nodular and wrinkled intima)

    • Absent
    • Present


    • Absent
    • Present
      • Size in three dimensions (mm)
      • Weight (g)

    Haematoma, if present2

    • Location of dissection flap
    • Size in maximum dimension (mm)
    • Plane of dissection within media, if applicable (a photograph may be appropriate)
      • Inner one-third
      • Mid-way through
      • Outer two-thirds
    • Periaortic adventitial haematoma, note if present
    • Stanford type, if assessable2,3 (however, this is usually assessed by the clinician and recorded in the clinical history)
    • Type A: Intimal tear in the ascending aorta that involves the ascending aorta only.
    • Type B: Intimal tear not involving the ascending aorta (in the descending aorta distal to the left subclavian artery and limited to the descending aorta).


    Submit four to six transverse sections, taken perpendicular to the direction of blood flow, in two cassettes.1 Often fragments cannot be orientated easily, in which case, it may be useful to take sections at right angles to each other so at least one transverse section is obtained. A transverse section is preferable to a longitudinal section for assessment of elastic architecture.

    Where the macroscopic appearance or initial microscopic evaluation is suggestive of aortitis, 5 or more additional sections should be submitted for processing.1

    Standard protocols for special stains required for blood vessel specimens should be available.1,2 Care should be taken to conserve tissue in case ancillary studies are required.

    • Alcian blue-Elastic Van Gieson (EVG) for acid mucopolysaccharides and elastin (this combined stain allows for assessment of architecture and acid mucopolysaccharides on a single slide)
    • Von Kossa silver nitrate for phosphate or Alizarin red S for calcium

    Record details of each cassette.

    An illustrated block key similar to the one provided may be useful.


    Prof Tony Thomas for his contribution in reviewing and editing this protocol.

    Block allocation key

    Cassette id
    No. of pieces
    Aortic wall  


    1. Stone JR, Basso C, Baandrup UT, Bruneval P, et al. Recommendations for processing cardiovascular surgical pathology specimens: a consensus statement from the Standards and Definitions Committee of the Society for Cardiovascular Pathology and the Association for European Cardiovascular Pathology. Cardiovasc Pathol. 2012;21(1):2-16.
    2. Boyle JJ, Rassl DM, Neil D, Suvarna K and Doran H. Tissue Pathways for Cardiovascular Pathology, The Royal College of Pathologists, London, 2008.
    3. Braverman AC (2010). Acute aortic dissection: clinician update. Circulation 122(2):184-188.

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