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How to Handle the Big MAC: Pitfalls and Safeguards During Mitral Valve Replacement

Thursday, October 16, 2014

This video incorporates both a discussion of mitral annular calcification (MAC) and a narrated operative portion detailing the techniques of handling MAC.


Thankyou Pr Blitz for this detailed technique to handle the big MAC. I want to ask if we can be sure of not damaging the circomflex artery after the annular reconstruction and insertion of the mitral prosthesis.
Thanks for your comment and question, Dr. Ziadi. In most cases one does not visualize the circumflex artery, so one can never be sure that it has not been injured. The most important tenets here are to be aware of where the artery runs closest to the annulus (i.e., P1 territory) and to be especially careful when debriding and suturing in that area. Most of the time, when the debridement and repair are properly performed, the artery is "pushed" laterally by the inverting tissue. I hope this helps.
May I know how long this procedure lasted? What were the Aortic Cross Clamp time and the Bypass time? I am asking this question because you were very comfortably working through the procedure and the successful outcome shows that every aspect was perfect. I would very much like to emulate and make my Aortic cross clamp time and Bypass time safe too.
Thank you for your question, Dr. Seshadrinathan. The aortic cross-clamp time was 115 minutes, and the CPB time was 125 minutes. This is roughly double the usual time for a conventional MVR. I am very liberal with the administration of cold blood cardioplegia, using both antegrade and retrograde.
Thank you, George. Fewer than 10% of the mitral valves I do have severe MAC that needs to be addressed in some fashion. Most of the time you know about it in advance from either the patient's chest xray, LHC, or echo.
I will thank you for this amazing procedure which is very teaching... I may ask you about your preference for the transseptal approach vs the left atriotomy route?? Is it constant for you?? What is about the post op arythmic and AVBlock incidence??? Comparing one to other approach?
I do prefer the transseptal approach for almost all my mitral valve procedures for a variety of reasons: First, the enhanced exposure obtained, particularly in patients with nonenlarged left atria; second, the ability to teach the procedure to trainees with the enhanced exposure. The incidence of postop arrhythmias appears to be increased as compared to conventional left atriotomy, but some studies comparing the two show no difference (e.g., Gaudino et al 1997). I hesitate to give percentages because of the variance across studies. I suggest you review some of the studies and come to your own conclusions: Gaudino 1997, Takeshita 1997, Masuda 1996, Lukac 2007, Utley 1995. Even if the incidence of sinus node dysfunction or atrial arrhythmias is indeed higher, in my opinion the tradeoff is worth the advantages described above. Great question!
Many thanks for sharing yet another educational video. Would you consider different set ups, and especially the actions of the assistant, for left and right handed surgeons in this situation? Best Regards, Aristotle
I have to say, Aristotle, I am not sure on the answer to that question. I am certain that left-handed surgeons and their assistants have devised maneuvers that mirror some of the ones used by the right-handed surgeon and his team.

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