Left Atrial Appendage

Interesting study regarding the Left Atrial Appendage-

[www.jafib.com]

EB

Hi EB,

Yep this is a good case study, and was mentioned in another post, glad you put the link up. I had sent a couple of these articles as PDFs to Hans for me to link to on the site, but got side-tracked with other things the last week and posting the link slipped my mind.

This article is one of a number studies coming out showing increasing awareness and investigation into the LAA as a key driver for a lot of AFIB/Tachy-arrhythmia's. Particularly for those with persistent AFIB and/or long standing paroxysmal with longer than 24 hour episodes.

The greatest prevalence of LAA involvement either as a major source, or in some cases the only source of continuing problems is found in those who have on going flippies after having one or more catheter ablations.

It's possible too that the defacto removal of the LAA during surgical/mini maze ablations is a significant factor that has contributed to the surgical approaches solid rates of success with persistent cases? In any event, it seems increasingly clear from both the surgical ablation experience and now from a large body of cases from Dr. Natale and his group who have focused on addressing this area head on for the last couple years in persistent and difficult paroxysmal cases with catheter ablation and isolation of the LAA when its found to be a core driver of AFIB or atrial tachy/flutter.

And the need to address the LAA in those kind of cases is what this report highlights. In addition, this single case study discusses the case of a persistent Afibber who had an initial ablation and then started having tachy-arrhythmias afterward and in the follow-up ablation the involvement of the LAA was noted and deliberate LAA-isolation was done and only after that has the man been free of any symptomatic arrhythmia.

However, this man's case is unusual in that they discovered some intra-LAA triggering of interior LAA-localized arrhythmia, even after full isolation of the LAA mouth, but which is not picked up on surface ECG!

It will be interesting to see how often this kind of silent but LAA-localized flippies actually happen, even in spite of full isolation? If its anything other than very rare, then that could encourage Docs to either rule in or out this kind of localized silent triggering inside an isolated LAA to decide whether or not anti-coagulation must continue life-long even for those whose blood flow velocity out of the LAA after the isolation proves good enough to avoid strokes within an NSR heart...

For those people who do wind up having this kind of localized silent arrhythmia inside the LAA, it certainly makes considering the Lariet device or surgical removal a good option.

Also, there are several other good articles in this issue of JAFIB that have very interesting discussions about the LAA and AFIB.

Shannon



Edited 1 time(s). Last edit at 10/22/2012 06:34PM by Shannon.

Here is another good overview of the Pathophysiology and Clinical Outcomes of the LAA in AFIB also from the same issue of JAFIB.com.

www.jafib.com

Thanks Shannon.

Just FYI, in the Five Box procedure Dr. Sirak installs an external clip; I believe the device is called an "Atriclip"

EB

That's good to know, EB, I asked Dr, Natale if and Atriclip would be a better option for me than Lariet-II, if they had a minimally invasive method of installing it as I liked the look of the Articlip when exploring it on their website. However he said Atriclip requires a significantly more invasive procedure ... ala a mini-maze/5Box or even open chest cardiac operation for which the Articlip was originally intended ... to be in position to install it than does the truly minimally invasive Lariet-II. However, both devices are similar in overall design and are trying to accomplish the same thing with a similar method by sealing off the LAA from the outside at the very hilt of the LAA where the LAA joins the wall of the left atrium.

The one other issue he brought up with the Atricure that makes him prefer the Lariet-II is that apparently by using a transeptal catheter balloon that is first placed inside the LAA endocardially and then expanded, it better delineates the true 'flush' level where the LAA opening joins the outside of the LA and also defines better where the inside opening of the LAA is within the Interior of the LA. That plus the relatively thinner double loop pre-tied stitch apparently allows the cardiac surgeon working with the EP in this combined endocardial/ epicardial procedure to snug that thinner stick down even closer to the hilt and thus more often get a more flush seal when viewed from the inside of the LAA where the ostium or mouth of the LAA opens up into the LA.

What you want ideally is as smooth a seal as possible with little to no remaining 'divit' or depression remaining where the mouth of the LAA used to open up into the actual LAA interior volume, as any depression or pocket-like depression from not having a very close and flush seal there can still allow the kind of 'A-wave' doppler inflow characteristics at the mitral inflow when seen on follow-up TEE that still makes possible the formation of Spontaneous Echo Contrasts (SEC) or frank clots to still form and not necessarily allow safe stopping of anti-coagulation in some cases.

Thats at least how I understand his point and he said that Lariet-II made it easier and more reliable to acheive said Flush seal between the inner opening of the LAA and the LA itself. That is why they are seeing a greater than 95% success rate in stopping Coumadin or other blood thinner after successful Lariet-II installation so far, and as doctor experience increases that overall very high rate is sure to climb he feels.

However, since Dr Sirac was already in there with his moderately less invasive procedure, certainly far less invasive than a full open chest heart/lung bypass, it makes perfect sense to use the Atriclip which is no doubt the best option once you are already inside the pericardial sack and have some visual access and confirmation for placement as well.

I like the special soft fabric contact surface on the Atriclip, but can also see where the nature of the clip and relative thickness of of the clip 'arms' itself can make it tricky when clipped over the outside hilt of the LAA to get a very flush seal on the inside of the LAA/LA junction compared to the much thinner nature of the pre-tied suture system that is the Lariet-II system that makes it easier to acheive a finer flush seal in experienced hands.

Anyway, the main thing for both systems is a good fit and then real life long protection should be the major reward! The good news too once either the Atriclip or Lariet-II is installed properly is that even if you should ever have another episode of AFIB or Flutter, your chances of a stroke forming clot are not any greater really than f or the average person at your age and CHADs 2 score in NSR! So the anti-coagualtion issue can truly become a concern of the past!

Here is a link to the Atriclip system: Atriclip LAA Exclusion system

And the Lariet-II device and system:Lariet-II study and video example of implantation

Dr. Natale and his partner Dr, Burkhardt have together installed almost 50 Lariet-II LAAC suture devices so far and more all teh time so out of the approximately 400+ cases since it was first introduced in 2009 they have done a large percentage of teh total cases for a single EP/team giving them a solid experience head start.

In most of these LAAC methods that include an endocardial transeptal step as part of the procedure, having an EP who is vastly experienced in transeptal puncture is a good insurance against one possible source of unwanted complication from the procedure. Otherwise, the Lariet-II seems to be a relatively safe with a good deal less serious complications than either the Watchman (which is supposedly improved with the latest generation) or the Amplatzer as well as those with surgical ligation and removal of the LAA with the added bleeding risk.

In any event, for anyone that requires life long anti-coagulation paying close attention to these new devices and the collective experience with multiple centers and EPs is a very good idea that could well eliminate the entire anti-coagulation risk without any blood thinning drugs at all!

Shannon

I have found the discussions of LAA ablation very informative and interesting. I am pretty sure I will be a candidate for the LAA ablation. I was a persistent Afibber who had a Natale ablation in May 2010 and have had three episodes of Aflutter since which required ECV. During my ablation Dr N found errant signalling in the LAA but did not have time to ablate or isolate the appendage. My local EP tells me he is 99% certain my flutter is left atrium. I have started back on anti-arrythmic drugs and warfarin and seem to have the beast under some control for the time being. I would like to delay my next ablation for awhile in hopes Dr N or others will get a better understanding the issues.

There appears to be significant stroke risk associated with LAA induced arrythmia, and increased ablation risks from the procedure due to the thin wall of the LAA. Has there be much thought given to skipping the ablation and just proceding to the Lariet II or other obliteration procedure of the appendage? What are the downsides?

Bill K

Good Question Bill,

As I understand it Dr. Natale prefers to first isolate the LAA, only if and when it is found to be a major source of triggering for you. The reason why and not just obliterate the LAA is taht even though that will indeed remove any electrical and mechanical connection between the LAA and LA and rest of the heart, there can still be triggering activity just on what was the inside ring or annulus where the inner mouth of the LAA once was,. That tissue might still be electrically active and still is part of the LA, even when the LAA itself in no longer there.

Thus, the primary goal is to stop all arrhythmia from the LAA region and insure unbroken NSR first and foremost and only then address the possible addded stroke risk from having a potentially slowed down and thus mechanically stunted LAA.

Besides there is still a fair chance for both you and I that we may have good enough remaining LAA velocity in and out that we can stop taking Coumadin and skip the Lariat-II as well?! I kind of doubt it in my case, but one can always keep the fingers crossed and then we could jsut go our merry way and get on with the rest of our lives with this issue finally behind us?

That is why he approaches this in a step-wise fashion to insure that each step is specifically necessary ... as it shown to be needed.

Shannon