This is a PPT presentation taken from archive (Made in 2012)
Please pardon , it lacks audio.
PDF version : Prof SV PTMC mitral valve crossing
Often times I have seen my Interventional colleagues struggle more at the mitral valve crossing than at IAS puncture during PTMC. Experience prevails over Image assistance. Assessment of LA size , IAS plane , and sub valvular disease seem to be critical. Probably the secret of success which I found out was , smart guys never hesitate to repeat IAS puncture site for optimal trajectory . Over the wire technique is not forbidden.
Unfortunately, TTE guidance is of little use to cross the mitral valve. Co-registration of fluro/3D TEE is promising , but most cardiologist continue to rely on their experience.
This always Intrigues me ! why we have abandoned retrograde crossing through the Aortic valve that avoids the dreaded IAS puncture. (Refer Dr V.K.Bahl AIIMS Newdelhi in a large series from Greece : Retrograde PTMC J Am Coll Cardiol 1998;32:1009–16)