Bifurcation angle is what ?

April 7, 2013 by dr s venkatesan

At any branch point three angles are possible .True bifurcation angle is formed between LAD and LCX .
The angle between LM and LAD or LM and LCX can also be important in specific situations ,especially when we encounter short left mains and Medina 1,1,0 lesions .
Major bifurcation angle can occur in mid segments as well , between LAD / major Diagonal , LCX and OM.
Logic would tell us the left main bifurcation angle is relatively fixed by the anatomical AV and IV grooves. Still early course of LAD and LCX can be out of grooves.
Further ,the bifurcation angle is imparted some amount of dynamism by cardiac cycle . It can vary between 80 -120 degrees (LAD/LCX).
Most importantly various angiographic views can alter the true angle (by illusion ) in dramatic fashion . RAO caudal view appear ideal to measure it. (LAO caudal make every bifurcation angle obtuse !)
Acute angled bifurcations are prone for stent related mechanical issues both during deployment and in the long term outcome . (When two stent technique is used) This is because , acute angled bifurcations has a tendency to drift the carina , and encroach the lumen which can create new turbulence . Of course final kissing balloon is expected to reduce this hemodynamic side effect at least on paper !

Dr.S.Venkatesan MD