Todayโs path rounds are on ๐ซ๐๐ง๐๐ฅ ๐ข๐ง๐๐๐ซ๐๐ญ๐ฌ! No particular reason, just thought it would be a fun one.
๐๐ก๐๐ญ ๐ข๐ฌ ๐ข๐ญ?
๐๐ง๐๐๐ซ๐๐ญ๐ข๐จ๐ง is when the blood supply to a tissue is blocked, causing that tissue to die. Infarcts in the kidney are somewhat unique because of their characteristic shape: each vessel in the kidney supplies a wedge shaped section of tissue, so when an infarct occurs, only that wedge of kidney is affected. So when you look at the kidney ๐ ๐ซ๐จ๐ฌ๐ฌ๐ฅ๐ฒ (without a microscope) you are able to see distinctive wedge shapes of infarcted tissue!
๐๐ก๐จ ๐ ๐๐ญ๐ฌ ๐ข๐ญ?
Any species can get this!
๐๐ก๐๐ญ ๐๐๐ฎ๐ฌ๐๐ฌ ๐ข๐ญ?
As mentioned previously, anything that causes a blockage of the blood supply to a tissue. Most commonly, these are ๐๐ฆ๐๐จ๐ฅ๐ข (a chunk of something in the bloodstream, usually a tumor or bacterial colony) or ๐ญ๐ก๐ซ๐จ๐ฆ๐๐ข (a blood clot). These get lodged in the small vessels supplying the kidney, causing a complete obstruction, and leading to the infarct. There are way too many causes of emboli/thrombi to list here!
๐๐จ๐ฐ ๐๐จ ๐ญ๐ก๐๐ฒ ๐๐ก๐๐ง๐ ๐ ๐จ๐ฏ๐๐ซ ๐ญ๐ข๐ฆ๐?
A neat thing about renal infarcts is you can tell how old they are, just by looking at them! When they first occur, they are often red due to ๐๐จ๐ง๐ ๐๐ฌ๐ญ๐ข๐จ๐ง (blood stagnant in the vessels because there is no outflow). The infarct will appear red for the first 2-3 days. Over the following 2-3 days, the blood sitting in this area will be broken down by ๐ง๐๐ฎ๐ญ๐ซ๐จ๐ฉ๐ก๐ข๐ฅ๐ฌ (one of the immune systemโs main clean-up cells), and the infarcted area will become white or pale. Over the next 1-2 weeks, the dead tissue is replaced by ๐๐ข๐๐ซ๐จ๐ฌ๐ข๐ฌ(scar tissue), which is white and tends to be โdepressedโ and shrunken in appearance.
๐๐ก๐ฒ ๐ข๐ฌ ๐ญ๐ก๐ข๐ฌ ๐ฌ๐ข๐ ๐ง๐ข๐๐ข๐๐๐ง๐ญ?
If the tissue is infarcted and dead/dying, then it obviously canโt perform normal kidney tissue functions! Single, small infarcts arenโt usually an issue, because you can lose up to 70% of your renal tissue function before you start to show signs of renal failure. On necropsy, we would call these types of infarcts an ๐ข๐ง๐๐ข๐๐๐ง๐ญ๐๐ฅ ๐๐ข๐ง๐๐ข๐ง๐ , meaning that it was found but wasnโt a significant cause of disease. However, if there are several, large infarcts, the animal may enter renal failure, and then the infarcts would be a very significant finding!
๐๐ก๐จ๐ญ๐จ๐ฌ
1) An ๐๐๐ฎ๐ญ๐ (just happened!) renal infarct, showing the dark red coloration due to congestion.
2) A ๐ฌ๐ฎ๐๐๐๐ฎ๐ญ๐ (happened a little while ago) renal infarct, showing it progressing to a pale tan color, still with a central area of red congestion.
3) A ๐๐ก๐ซ๐จ๐ง๐ข๐ (happened a long time ago) renal infarct, showing a white, shrunken scar.
4) Renal infarcts can be seen even from the outside of the kidney! If this kidney looks weird to you, thatโs because it kind of is. Cattle have lobulated kidneys, where each kidney is made up of a bunch of smaller โtraditionalโ kidneys. Neat!
๐๐จ๐ฎ๐ซ๐๐๐ฌ
Maxie, G. Jubb, Kennedy and Palmerโs Pathology of Domestic Animals, Volume 2. Sixth Edition.
Photos courtesy of University of Calgary Veterinary Medicine Diagnostic Services Unit.
