Medical Device Daily Executive Editor

FORT LAUDERDALE, Florida – The annual meeting and exhibition of the Society of Thoracic Surgeons (STS; Chicago) – the year’s being the 44th – may be the most polite gathering among the dozens of medical association gatherings held every year.

Speaker presentations are marked by multiple thanks (we counted near two dozen in the address by the society’s president), obviously pre-scripted questions (and answers), then additional thanks for those “very intelligent” and “thoughtful” questions, for those both pre-scripted and from-the-floor-unscripted, those questions only offering the mildest of qualifications and challenges.

(And an unscientific estimate of traditional ties-and-suits compared to those at the more casual American Heart Association meetings: 3-to-1.)

This intense politeness may be the result of the society’s continued domination by the traditional open-surgery community – perhaps suggested by the society’s name? – perhaps producing an in-group, small-village aura with no great willingness to ruffle feathers.

But there is a quiet and intense undertone of debate here concerning the new technologies and, especially, the evolution of percutaneous therapies targeting the heart and lungs.

One indication of the underlying competitive flavor of the meeting is that it is preceded by STS/AATS Tech-Con, a gathering held on the preceding Saturday and Sunday, highlighting the most advanced computer and robotically-assisted technologies as a separate, but linked, event.

Tech-Con provides presentations offering overviews of the newest techniques that cardiothoracic surgeons are moving (or being pushed?) into, a “Simulator Village” allowing surgeons to get a hand (and handle) on these new techniques (though, somewhat nervously with other surgeons peering with great interest over their shoulders at how they’re doing with perhaps unfamiliar instrumentation), and a concluding debate on the value of randomized controlled trials to evaluate these new technologies.

Obviously useful, how can you doubt? some said; but alternate views suggest that these new technologies come with so many more variables that such RCTs are more difficult to do and have not yet been highly powered so may not tell you very much.

The debate between standard surgical approaches and percutaneous was then highlighted early on in the opening Monday session of the regular STS meeting by one of three “memorial” papers (honoring J. Maxwell Chamberlain), focusing on the recent and steep upward spike in percutaneous closure of septal defects and patent foramen ovales, both openings in the heart thought to be risks for later cardiovascular problems and, possibly but still highly theoretical, migraine headache.

Tara Karamlou, MD, of Oregon Health and Science University (Portland), presented a paper titled “The Rush to Atrial Septal Defect Closure: Is the Introduction of Percutaneous Closure Driving Utilization?” — the title itself indicating an underlying unease with a percutaneous approach to this problem (if there’s a “rush,” are things moving much too fast?)

Karamlou and four other researchers looked at the closure of secundum atrial septal defects over a 15-year period (1988-2003) and noted the increased popularity of the percutaneous approaches to closing these defects.

Popular indeed: 92 such procedures in 1998, 4,055 in 2003, from the database the group used, an increase of 4,293%.

Karamlou associated that rocket-propelled jump in procedures with the approval of the Amplatzer device, made by AGA Medical (Golden Valley, Minnesota) and receiving first approval in September 2001 (Medical Device Daily, Sept. 14, 2001).

The primary shift, she reported, came in 2001, with surgical closure decreasing by 20% and percutaneous closure increasing by 1,084%.

The concern proposed by Karamlou’s team was that this increase had driven the uptake of percutaneous approaches by a variety of forces rather than “medical need”: these included the greater availability of the devices to provide percutaneous therapy, enhanced reimbursement for the procedure and patient demand for the percutaneous approach, even among asymptomatic patients – the last lowering the “threshold,” that is, a reduced number of the patient’s risks.

The research reported that whether the surgical closure approach or the percutaneous approach was used, rates of mortality were the same, under 1%, and Karamlou indicated no significant differences in thromboembolism, though providing no figures for that endpoint.

While those clinical observations would appear to indicate strong support for the percutaneous approach, the researchers concluded by saying that the decreased morbidity of percutaneous closure was only “perceived,” indicating a certain amount of distrust or disdain for the percutaneous approach.

The study’s overall conclusion: “In the absence of meaningful benchmarks, prospective studies comparing outcomes, criteria and cost for SC [surgical closure] versus PC [percutaneous closure] are needed to determine whether increased ASD [atrial septal defect] closure rates are justified.”

Despite the surgical-percutaneous competition, device technology clearly is aiding older, standard, methods in this sector.

Ralph Damiano, MD, of Washington University School of Medicine (St. Louis), discussed the traditional Cox-Maze produced used adjunctive to open surgery for treating atrial fibrillation (AF), a “cut-and-sew” procedure that is workable and effective but requiring cardiopulmonary bypass and arresting the heart.

Damiano and his group have developed what they term the Cox-Maze IV procedure which substitutes the use of bipolar radio frequency energy for the cut-and-sew method. He reported superior results in 170 procedures, using Cox-Maze IV.

Despite these successes, Damiano said large improvement is needed and he said that a minimally invasive procedure would ultimately be developed that would be broadly applicable to all patients.

He rather optimistically predicted that advances in pre-operative imaging and diagnostics “will soon allow us to better define the mechanisms of atrial fibrillation in each individual patient” to produce “startling improvement” in treating AF.

But Damiano’s prediction that this will happen “soon” — and an optimistic headline in the STS convention newspaper headlined “Future Bright for Atrial Fib Surgery” — contradicts a general skepticism, recently reported by MDD, about the clinical validation concerning what causes AF and the most effective treatments (“Controversy, uncertainty cast large shadows over AF ablation,” MDD, Jan. 23, 2008).