A med student asked: why do we need epicardial coronary arteries? Can’t the ❤️ utilize the abundant oxygenated blood within it? We then talked about transmyocardial revasc (TMR), which apparently has resurfaced some recently. Thought I’ll summarize my read on it in this thread 👇 
1. TMR theory is based on reptilian circulation. Reptiles are devoid of epicardial arteries & hence rely on intramyocardial sinusoids for tissue oxygenation.
2. 1st TMR attempt (sort of) was by Claude Beck in 1935. Beck noted that external myocardial injury > new vessel formation
2. 1st TMR attempt (sort of) was by Claude Beck in 1935. Beck noted that external myocardial injury > new vessel formation
3. In 1970s myocardial needle acupuncture was attempted to replicate reptilian circulation. However, the created channels prematurely closed w fibrous growth.
4- In 1980s laser was introduced to increase channel patency. This was thought to be a game changer for refractory angina
4- In 1980s laser was introduced to increase channel patency. This was thought to be a game changer for refractory angina
5- TMR produced symptomatic improvement in several RCTs even in pts who had channel closure.This suggested alternative mechanism of efficacy (angiogenesis).
6- laser TMR is FDA approved & is in the guidelines 4refractory angina.
7- >50K cases performed till 2010 but slowed since
6- laser TMR is FDA approved & is in the guidelines 4refractory angina.
7- >50K cases performed till 2010 but slowed since
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