Differences between the Saltman & Wolf procedures to treat AF -- May, 2006

ABBREVIATIONS

CA: Catheter-approach ablation

AR: Anti-arrhythmic

INTRODUCTION

There has been some discussion [on the A-fibcures bulletin board) of the differences between the Wolf mini-maze and the Saltman micro-maze. I would like to offer my understanding of these differences along with a few comments on their significance...

Both these procedures are PVI-centered; they isolate the PVs but do not do the Cox-mini-maze set of blocking lesions, as done by Drs Damiano, McCarthy, Ad, and Geiss. Current conventional wisdom has it that PVI is most effective with paroxysmal/intermittent AF.

Please note: In the following, “intermittent AF” refers to AF that comes and goes without cardioversion. “Continuous AF” is AF that keeps going unless cardioverted or that does not respond to cardioversion. These categories – in addition to the duration of AF, or “chronic-ity” – are the only ones that have implications for treatment (so far). 

SUCCESS RATES

Saltman: as quoted to Kerry acker, c 70% for intermittent; c 50% for continuous.

Wolf: Statistics for recent cases not yet available but reportedly will be in a couple of months (Fall of 2006?).  Early this year, the rate quoted to me was 89% (85% off all meds), but figure not broken down by type of AF. Comparing these vague success rates is a risky business -- see Success rates, competition…. 

LESION SETS

PVI-Centered Surgeries

A case can be made for the potential usefulness of each one of these additional measures, but I do not know their relative importance.

The part played by the Ganglionated Plexi deserves come comment. The variations of the Cox Maze surgery and the multitude of CA procedures, no matter how brilliantly conceived and well executed are still trying to "trap the horse after it has escaped from the barn". It is natural, therefore, that those studying AF would want to focus on the elements in the causal chain that precede the escape of the errant impulses into the heart. Focus on genetics, inflammation and cardiac autonomic nervous system abnormalities are examples of this approach. Targeting these factors will presumably have less potential for damaging the heart than the numerous, albeit tiny, burns of CA and have fewer toxic or unpleasant side effects than continuous AR medication.

ENERGY SOURCES

Saltman: Microwave. This relatively cool source should minimize collateral damage. There is no way go assure transmurality  (according to a person who asked him this question, I believe, at a convention).

Wolf: Radio- frequency (RF). Atricure clamp reduces temperature needed for transmural lesions, and assures transmurality.

INVASIVENESS

Saltman: His procedure is totally endoscopic, making six incisions that are big enough for his instruments to be inserted. The surgeon has no direct view of what he is doing. On the other hand, Saltman had done a great many of these procedures and I have not heard of any problems resulting from this potential drawback. And, Saltman says his approach is relatively easy to learn. This level of invasiveness usually requires only an overnight stay and a return to full activity in several days.

Wolf: His procedure requires a three or four inch lesion on each side of the rib cage, allowing the surgeon a direct view of much of what he is doing.  There are also 2 smaller incisions on each side to allow for the insertion of scope and instruments. The patient stays in the hospital for 2 or 3 nights, with return to full activity in 2+ weeks.  [Please note: Recovery times will vary greatly among individuals.]

OTHER FEATURES

Wolf: ... does EP testing to make sure that his PVI and Ganglionated Plexi ablations have been effective.

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So where does that leave us?

In terms of outcome, meaningful comparison is impossible because of the situation described above. Saltman, at least, states some plausible statistics; we’ll have to wait to see what Wolf presents.

In terms of process, I would say that there is little to choose between the two of them, because we do not know the implications of the lesions/ablations they do in addition to PVI. Wolf does more lesions; the Ganglionated Plexi may turn out to be an important focus.

So… I would really like to know the significance of Saltman’s LA flutter lesion as compared to the Ligament of Marshall removal and ablation of selected Gangionated Plexi done by Wolf. How often does LA flutter occur and does Saltman’s lesion prevent it? And does this lesion deal with circuits that may form in the area vacated by the removal of the LAA? (The lesion is accomplished before the LAA is removed, but I cannot say whether this makes any difference.)

What I would like to see even more would be for the two of them to combine the best of both their procedures. Even better would be for this combo to include appropriate CA ablations and the use of other energy sources (such as HIFU)  to develop what might be a temporary “gold standard” for the minimally invasive surgical treatment of intermittent AF.

What do you think?