Friday, 17 November 2017

Mesorectal fascia (MRF)

In total mesorectal excision (TME), «the entire mesorectal compartment including the rectum, surrounding mesorectal fat, perirectal lymph nodes, and its envelope, the MRF, is completely removed by precise dissection along anatomical planes [1].»«The mesorectal fat is surrounded by the MRF, (...) [1].» It surrounds the mesorectal fat outside the rectum or the sphincters in the lowest part [2]:
Source: The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.

Source: The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.

«The MRF is only circumferential in the low-rectum below the anterior peritoneal reflection.The MRF does not apply to the anterior peritonealized surface of the anterior mid- and high rectum [1]»:
Source: The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.

«The MRF plays a crucial role in the treatment planning. In TME the mesorectal fascia is the resection plane and it has to be tumor-free. A distance of the tumor to the mesorectal fascia of ⩽1 mm is regarded as not suitable for TME and is called an involved MRF [1].»
Source: The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.

T-stage and mesorectal fascia involvement in the axial plane
Source: The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.

«Low rectal cancer has a higher local recurrence rate. The distal tapering of the mesorectal fat implies that low rectal cancer more easily invades the MRF, pelvic wall, and surrounding organs [1]»:
Source: The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.

«The low rectum is totally covered by the mesorectal fascia. In the mid-rectum, it is covered by the mesorectal fascia on the posterior and lateral side, but on the anterior side, it is covered by the visceral peritoneum [1].»
Bibliographic references:
[1] The Radiology Assistant: Rectal Cancer - MR staging 2.0. Radiologyassistantnl. Available at: http://www.radiologyassistant.nl/en/p56195b237699d/rectal-cancer-mr-staging-20.html. Accessed November 17, 2017.
[2] Glimelius B, Beets-Tan R, Blomqvist L, et al. Mesorectal fascia instead of circumferential resection margin in preoperative staging of rectal cancer. J Clin Oncol. 2011 Jun 1;29(16):2142-3. Available at: https://doi.org/10.1200/JCO.2010.34.4473.