should I have PEI or Surgery for a 6 cm thyroid cyst

Hi, I am reaaly confused as I dont know what to do. Please help me and advise me.
I have this thyroid cyst on my right lobe for few years now which is around 6 cm. There is also a couple of very very small nodules(less than 1 cm) next to it. My thyroid function is normal now.  

I was living with this big cyst for few years without any issue. However, recently I was going to have a heart surgery to change my aortic root (because I also suffer from Marfan Synd) and my surgeon said that this big cyst is pushing your windpipe and should be dealt with before or at the time of your heart surgery.  

therefore, he referred me to a ENT surgeon which I saw yesterday, he said he is going to remove the right lobe at the same time of my heart surgery. So both surgeries will be done with one long general anasthetic.  However, I have found out about PEI and its success rate and therefore I have become really reluctant to have the right lobectomy specially as I have recently found out that there is a possibility that I can become hypothyroidism later on after lobectomy. Also, I am worrid about if they can keep me under general anasthetic for such a long time to do 2 surgeries.

PLEASE Please help me as I do not want to change the normal function of my thyroid with lobectomy, if PEI can really help me? They are going to fix a date quite soon to do the surgeries but I want to call them and stop that and look for someone who can does PEI. Please also tell me how I can find out who does PEI in London?