Aorta

Background

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.

Fresh tissue received
  • No
    • Non-routine fixation (not formalin), describe.
  • Yes
    • Special studies required, describe.
    • Ensure samples are taken prior to fixation.
Intraoperative consultation
  • 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 InspectionBack to top


Orientate and identify the anatomical features of the specimen.

Orientation markers

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:

Procedure

Record as stated by the clinican

Options
  • 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
  • ‚ÄčOther, specify

Shape

Describe the overall shape if intact.

  • Normal
  • Dilated
    • Fusiform
    • Saccular

DissectionBack to top


Section the specimen perpendicularly to the luminal surface.1

Internal InspectionBack to top


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

Thrombus2

  • 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 assessable 2,3 (however, this is usually assessed by the clinician and recorded in the clinical history) 
Stanford Classification2,3
  • 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).

ProcessingBack to top


Submit four to six transverse sections, taken perpendicular to the direction of blood flow, in two cassettes.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.

Special stain protocol example 2
  • 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.

Acknowledgements

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

Block allocation key

Cassette id
Site
No. of pieces
A-B
Aortic wall  

ReferencesBack to top


  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.