Surgical ablation of atrial fibrillation with off-pump,
epicardial, high-intensity focused ultrasound: Results of a
Jean Ninet, MD,aXavier Roques, MD,bRainald Seitelberger, MD,cClaude Deville, MD,bJose Luis Pomar, MD,d
Jacques Robin, MD, PhD,aOlivier Jegaden, MD,aFrancis Wellens, MD,eErnst Wolner, MD,c
Catherine Vedrinne, MD, PhD,aRoman Gottardi, MD,cJavier Orrit, MD,dMarc-Alain Billes, MD,b
Drew A. Hoffmann, PhD,fJames L. Cox, MD,gand Gerard L. Champsaur, MDf
Background: A simplified alternative to the Cox maze procedure to treat atrial
fibrillation with epicardial high-intensity focused ultrasound was evaluated clini-
cally, and the initial clinical results were assessed at the 6-month follow-up visit.
Methods: From September 2002 through February 2004, 103 patients were pro-
spectively enrolled in a multicenter study. Atrial fibrillation duration ranged from 6
to 240 months (mean, 44 months) and was permanent in 76 (74%) patients,
paroxysmal in 22 (21%) patients, and persistent in 5 (5%) patients. All patients had
concomitant operations, and ablation was performed epicardially on the beating
heart before the concomitant procedure. The device automatically created a circum-
ferential left atrial ablation around the pulmonary veins in an average of 10 minutes,
and an additional mitral line was created epicardially in 35 (34%) patients with a
handheld device by using the same technology.
Results: No complications or deaths were device or procedure related. There were
4 (3.8%) early deaths and 2 late extracardiac deaths. The 6-month follow-up was
complete in all survivors. At the 6-month visit, freedom from atrial fibrillation was
85% in the entire study group (80% in patients with permanent atrial fibrillation,
88% in the 35 patients who had the additional mitral line, and 100% in patients with
paroxysmal atrial fibrillation). A pacemaker was implanted in 8 patients. Only the
duration and type of atrial fibrillation significantly increased the risk of recurrence.
Conclusion: Epicardial, off-pump, beating-heart ablation with acoustic energy is
safe and cures 80% of patients with permanent atrial fibrillation associated with
long-standing structural heart disease.
with age with a prevalence of 4% in the population more than 60 years of age and
more than 9% after 70 years of age.1
AF is associated with a mortality rate that is 1.5 to 2 times the expected rate in
the general population after adjustment for other cardiovascular conditions,1,2and
despite the benefits of anticoagulation, it is still responsible for thousands of strokes
caused by systemic emboli with the subsequent burden on health care costs.3,4
The medical management of AF is well established,2but little was offered for the
cure of AF until the direct interventional therapy of AF was initiated by Cox and
colleagues5,6in the form of the surgical maze procedure in 1987. The Cox maze
procedure remains the gold standard for the treatment of AF, with 80% to 95%
freedom from AF at 15 years of follow-up.7Haissaguerre and colleagues8subse-
trial fibrillation (AF) is a significant public health problem, affecting 2.4
million patients in the United States alone and approximately 6 million
patients in the Western world and Japan. The incidence of AF increases
From Hôpital Cardiologique Louis Pradel
and Claude Bernard University,aLyon,
France; Hôpital Haut Lévêque and Victor
Segalen University,bBordeaux, France;
AKH and Vienna University,cVienna,
Austria; Hospital Clinico and University of
Barcelona,dBarcelona, Spain; Onze Lieve
Vrouwziekenhuis,eAalst, Belgium; Epicor
Medical, Inc,fSunnyvale, Calif; and the
Washington University School of Medi-
cine, St Louis, Mo.
Received for publication Feb 6, 2005; revi-
sions received May 7, 2005; accepted for
publication May 18, 2005.
Champsaur, MD, 1430 Channing Ave,
Address for reprints: Jean Ninet, MD,
Cardiac Surgery, Hôpital Cardiologique
Louis Pradel, 59 Blvd Pinel, 69003,
Lyon, France (E-mail: jean.ninet@chu-
J Thorac Cardiovasc Surg 2005;130:803-9
Copyright © 2005 by The American Asso-
ciation for Thoracic Surgery
Ninet et alEvolving Technology
The Journal of Thoracic and Cardiovascular Surgery●Volume 130, Number 3803.e1
quently demonstrated that most individual episodes of par-
oxysmal AF originate from premature atrial beats located in
or near the orifices of the pulmonary veins. This concept set
the stage for the development of catheter-based technolo-
gies aimed at isolating the orifices of the pulmonary veins
from the remainder of the left atrial wall, thereby isolating
the triggers that induce AF and curing the arrhythmia.
Because of the complexity of the Cox maze procedure,
several modifications have been introduced in an effort to
simplify and shorten the operation. Some authors abandoned
the right-sided lesions completely yet still attained AF cure
rates in the range of 75% to 85%.9,10In addition, alternatives
to the cut-and-sew techniques using various energy sources
developed in an attempt to replicate the Cox maze lines of
atrial conduction block more quickly.11-16However, these new
energy sources are all faced with similar challenges. When the
energy is applied from the endocardium (either through cath-
eters or during surgical intervention), it is impossible to deter-
ensure transmurality but might also result in damage of the
surrounding structures, such as the esophagus.13,17If these
various energy sources are applied from the epicardium, their
problems might be even more complex because of their ther-
mal gradient nature. These problems include overcoming the
cryotherapy) and difficulty in propagating through epicardial
fat. Moreover, even when applied epicardially, they can still
cause damage to vital nearby structures.18
High-intensity focused ultrasound (HIFU) is an energy
source that specifically addresses the problems associated
with thermal gradient energy sources for the epicardial
ablation of AF. This report details the results of the first
clinical feasibility study with this new energy source in
which HIFU is applied epicardially on the beating working
heart without the use of cardiopulmonary bypass.
Material and Methods
Conduct of the Study
The clinical trial was a prospective multicenter study performed at
5 different institutions in 4 European countries in which 14 dif-
ferent surgeons participated. Identical protocols were systemati-
cally reviewed by each institutional review board and were further
approved by the National Competent Authority of each country.
Each enrolled patient signed an informed consent form for the
procedure and for the subsequent follow-up visit, for which the
physical presence of the patient at the center was required.
Patients were candidates for an Epicor Medical HIFU ablation
(Epicor Medical, Inc, is a St Jude Medical company) if they had
any form of AF present for at least 6 months before the operation
and were already scheduled to undergo concomitant cardiac sur-
gery for the correction of valvular, ischemic, or congenital heart
disease. Exclusion criteria included acute or active infection, se-
vere heart failure, severe progressive extracardiac disease, a prior
cardiac operation, and the presence of a previously implanted
The primary end point for the study was feasibility determined
by the time required for sizing, insertion, and epicardial ablation
by using the Epicor Medical Ablation System on the beating heart.
Secondary end points included (1) safety, defined as the incidence
of device-related and non–device-related complications and mor-
tality during and 6 months after the operation, and (2) freedom
from AF, atrial flutter, or both, as determined by means of surface
electrocardiography (ECG) and Holter monitoring at the 6-month
The Epicor Medical Ablation System is a US Food and Drug Ad-
ministration–approved, CE-marked system designed to deliver HIFU
energy to ablate cardiac tissue. The system consists of the Ablation
Control System (ACS) generator, a family of disposable ablation
devices and a set of accessories. The ACS is a microprocessor-based
unit that provides acoustic power to the ultrasound transducers.
The UltraCinch device (Figure E1) is an array of multiple ultra-
sound transducers that is used to produce a transmural circumferential
left atrial lesion around the pulmonary vein orifices. An additional
tool, the UltraWand, is a handheld ablation device with 2 transducers
only for the epicardial creation of additional linear lesions.
The transducers are positioned on the epicardium but separated
from direct contact with the cardiac tissue by a thin perforated
membrane. Room temperature normal saline is circulated between
the membrane and the transducers during ablation to enhance
acoustic coupling and cooling. The transducers (10 ? 15 mm) are
designed to deliver HIFU energy up to a distance of 10 mm from
their surface (Figure E2), thus covering all possible thicknesses of
the human left atrial free wall.19Beyond the focal point, the energy
dissipates within the left atrial cavity without exposing the sur-
rounding structures to potential collateral damage. The proprietary
algorithm generated by the ACS uses a combination of frequency,
power, and duration at which the transducers are activated and
powered (from 3.8 to 6.4 MHz and from 15 to 130 W) to generate
3 sequential stages of ablation. The ablation process begins with
the deep ablation stage, during which the energy is deposited distal
from the transducer in the subendocardial zone, followed by the
intermediate stage in which energy is deposited in the midmyo-
cardial layer, followed by the surface stage for epicardial energy
deposition. During the first 2 stages, each transducer is activated
sequentially, and the energy is pulsed, whereas during the third
stage, transducers are staged 3 by 3 with nonpulsed energy to
eliminate any residual gap within the epicardium. Thus the lesion
is built up from the endocardium back to the epicardium and is
complete within approximately 10 minutes. The UltraWand is
activated in a similar fashion for the creation of linear lesions
during approximately 1 minute.
The ablation procedure was performed on the beating working
heart before beginning the concomitant intracardiac procedure,
thus avoiding additional cardiopulmonary bypass and aortic cross-
clamp times. After opening the pericardium, the pericardial reflec-
Evolving TechnologyNinet et al
803.e2The Journal of Thoracic and Cardiovascular Surgery●September 2005
tions around both the superior vena cava and inferior vena cava
were dissected free to gain access to both the transverse and
oblique sinuses. A specially designed introducer-sizer was passed
behind the superior vena cava into the transverse sinus and guided
into the oblique sinus and beneath the inferior vena cava, thereby
completely encircling all 4 pulmonary veins. The graduated intro-
ducer-sizer was used to measure the circumference of the left
atrium to select the proper size of UltraCinch and was also used to
lead the UltraCinch around the left atrium. Once the introducer-
sizer was removed, the 2 ends of the UltraCinch were approxi-
mated with tourniquets placed on the appropriate sutures at each
end to snug the device securely around the left atrium. The ablation
cycle was then initiated and progressed automatically until the
cycle of ablation had been completed. During the ablation, the
surgeon was free to continue with the purse strings and other
preparation for the subsequent concomitant procedure. If deemed
advisable, additional lesions could be created epicardially with the
UltraWand, particularly the mitral line lesion extending from the
pulmonary vein–encircling lesion down to the mitral valve
From September 2002 through February 2004, 103 patients (59
male and 44 female patients) were enrolled. AF was categorized
as being permanent in 76 (74%) patients, paroxysmal in 22
(21%) patients, and persistent in 5 (5%) patients.20Fifty (49%)
patients were 70 years of age or older, and 19 (18%) were older
than 75 years (Table 1). Comorbidity was relatively common,
with chronic obstructive pulmonary disease in 15 patients and
renal insufficiency in 7 patients. A history of cerebral ischemia
was documented in 5 patients, repeat transient ischemic attack
was documented in 5 patients, and peripheral embolism was
documented in 3 patients. Catheter ablation had been attempted
previously in 3 patients.
Surgical intervention was conducted through a median ster-
notomy in 95 patients, through a ministernotomy in 5 patients,
and through a limited right thoracotomy in 3 patients. A single
additional mitral line was also created epicardially with the
UltraWand in 35 (34%) patients. The UltraWand became avail-
able only during the last third of the study, and its use was left
up to the operator’s judgment. Concomitant cardiac procedures
are listed in Table 2. There were no attempts to exclude the left
Until discharge, patients were monitored daily with standard 12-
lead ECG recordings. Dictated by the type of concomitant heart
disease, anticoagulant therapy was prescribed for the first postop-
erative week, and for the longer term, warfarin sodium (Couma-
din) therapy was left to the judgment of the investigators. On the
basis of previous studies, prophylactic antiarrhythmic drug therapy
was recommended for at least 3 months after the operation.8,9,14-18
External cardioversion was not encouraged in the early postoper-
Data were collected on standard case report forms approved by
each institution’s institutional review board. In addition to the
demographic data collected at the preoperative visit, a standard
12-lead ECG, 24-hour Holter monitoring, and transthoracic echo-
cardiography were performed at the time of hospital discharge and
at the 3- and 6-month follow-up visits. Event-monitoring systems
(Instromedix, San Diego, Calif) were required in patients with
paroxysmal or persistent AF who became symptomatic between
the 3- and 6-month visits. The 6-month follow-up period was
completed for all 103 patients as of June 10, 2004, with no patient
lost to follow-up during that period. The mean follow-up period
was 177 days (median, 185 days), with a range of 2 to 232 days.
Adverse events and their relatedness to the device or the procedure
were collected and reviewed by each clinical investigator and the
local clinical coordinator and further assessed by a clinical events
committee of independent US thoracic and cardiovascular sur-
geons not involved in the study.
Data were entered into a computerized database and analyzed with
a statistical package (STATISTICA; StatSoft, Inc, Tulsa, Okla).
The descriptive summary of data included mean ? standard devi-
ation and 95% confidence intervals for continuous variables and
proportions for categoric variables. Between-group differences
were assessed with t tests and analysis of variance in more than 2
groups for continuous variables and ?2tests for nominal variables.
All reported P values are 2 sided.
TABLE 1. Patient demographic information (n ? 103)
AF duration, mo
LA diameter, mm
SD, Standard deviation; AF, atrial fibrillation; LA, left atrium; LVEF, left
ventricular ejection fraction.
TABLE 2. Concomitant procedures
Proceduren ? 103%
Mitral valve surgery (2 ? CABG;
32 replacements and 14
Double-valve surgery (8
mitrotricuspid and 13
Aortic valve replacement (3 ?
Coronary artery bypass surgery
Atrial septal defect closure
Ventricular septal defect closure
(1 with pulmonary stenosis)
CABG, Coronary artery bypass grafting.
Ninet et alEvolving Technology
The Journal of Thoracic and Cardiovascular Surgery●Volume 130, Number 3803.e3
All 103 consecutive patients enrolled in the protocol were
available for feasibility and safety analysis. However, in 3
patients the ablation algorithm was ended prematurely be-
cause of an ACS malfunction early in the study. Although
included in the feasibility and safety analysis, these 3 pa-
tients were not expected to be free from AF and hence were
not considered for the efficacy analysis.
Evaluation of Feasibility
Various aspects of the procedure were timed (Table 3). The
combined time required to insert the UltraCinch device and
perform the automated ablation averaged 11.9 minutes, all
of which was off-pump time. During the actual ablation
itself (mean time, 9.7 minutes), surgeons continued to pre-
pare the heart for the subsequent concomitant procedure.
Because this was a required part of the concomitant cardiac
surgery, the AF ablation portion of the procedure added an
average of only 2.2 off-pump minutes to the overall com-
bined operative procedure. No extra time was required for
epicardial fat dissection or removal.
Evaluation of Safety
No early or late complications or deaths were related to
either the HIFU device or to the ablative procedure. The
observed complications and mortality were characteristic in
both magnitude and frequency of those commonly observed
after cardiac surgery in patients with the same clinical
profile undergoing the same concomitant procedures.21
Complications. Early complications (?30 days after
surgical intervention) occurred in 20 patients. Postoperative
bleeding necessitating surgical reexploration occurred in 6
(5.8%) patients and was unrelated to the AF ablation. A
permanent pacemaker was required in 5 patients. Strokes
occurred between postoperative days 1 and 4 in 3 patients,
but each resolved rapidly with medical therapy, with no
residual effects in any patient. Two patients experienced an
episode of femoral artery embolism on postoperative days 1
and 10, respectively, both of which were resolved by means
of embolectomy. One patient had a serious deep wound
infection (sacral decubitus ulcer) that required repeated sur-
gical debridement. Late complications (?30 days after sur-
gical intervention) consisted of sinus node dysfunction re-
quiring a permanent pacemaker in 3 patients, ventilation
pneumopathy in 1 patient, delayed tamponade treated with
pericardial drainage in 1 patient, and a transient ischemic
attack in a patient in sinus rhythm but who was severely
Mortality. The operative mortality rate (30 days postop-
eratively) was 3.8% (n ? 4), including 3 patients older than
75 years. Two patients died from left ventricular failure
because of prolonged bypass and crossclamp times, and 2
other patients died from multiorgan failure after aspiration
pneumonia and prolonged ventilation in one case and gen-
eral sepsis caused by repeat excisions of a bed sore in the
other case. Late mortality consisted of 2 patients who died
from noncardiac causes: multiorgan failure in a 74-year-old
man who died 2 months after a mitral valve replacement
complicated by a prolonged period of assisted ventilation
and bilateral pneumopathy and infection of an aortoiliac
graft implanted 2 months after coronary artery bypass graft-
ing in a severely diabetic patient.
Evaluation of Efficacy
Absence of AF or atrial flutter was evaluated in 94 patients
available at the 6-month follow-up visit (excluding the 3
patients mentioned above who were not considered for the
efficacy analysis and the early and late deaths). In addition
to the American Heart Association/American College of
Cardiology classes of AF, the surgical classes included
intermittent (paroxysmal plus persistent) AF (n ? 27) and
continuous (permanent) AF (n ? 76).22,23At the 6-month
follow-up visit, freedom from AF was 85% in the entire
study group (n ? 94) and 88% in the 35 patients who
received the additional mitral line. Given the late and non-
controlled introduction of the UltraWand, the study was
incapable of discerning any potential added benefit of the
mitral line lesion. Remarkably, in the group of 76 patients
who had continuous AF with a mean duration of 52.9
months (95% confidence limit, 37.8-69 months), the free-
dom from AF at 6 months was 80%. Thus epicardial off-
pump, beating-heart ablation performed by using an auto-
mated 10-minute algorithm with HIFU cured 80% of
patients in permanent AF associated with long-standing
structural heart disease requiring surgical treatment. Equally
as gratifying was the observation that 100% of patients with
intermittent AF were free from AF at 6 months. Two
patients who were in atrial flutter at the 3-month visit
underwent an external cardioversion and remained in stable
sinus rhythm thereafter. There were no instances of left
atrial reentrant tachycardia or left-sided flutter. Patients with
intermittent AF who were free from AF at the 3-month visit
were entered into an event-monitoring program. No epi-
sodes of AF or atrial flutter were documented in any of these
patients between the 3- and 6-month visits.
Eight pacemakers were implanted during the follow-up
period, 4 for complete heart block with normal regular atrial
TABLE 3. Feasibility data (n ? 103)
Sizing time, s
Device introduction time, s
Ablation time, min
UltraCinch size (in no. of
Evolving TechnologyNinet et al
803.e4The Journal of Thoracic and Cardiovascular Surgery●September 2005
activity and 4 (double chamber) for sinus node dysfunction.
The assessment of left atrial function was not part of the
protocol, but transthoracic pulsed Doppler echocardiogra-
phy was available in a small cohort of 23 patients. All
patients in sinus rhythm were documented to have left atrial
contraction by the presence of a transmitral a-wave 6
months after the operation. Diastolic left ventricular func-
tion was preserved, with a peak-to-peak atrial velocity ratio
of 1.90 ? 0.56, with the usual restrictions caused by the
high incidence of concomitant mitral valve surgery. By
using univariate analysis of preoperative and intraoperative
variables, predictors for residual AF 6 months after surgical
intervention were preoperative AF duration (duration of
87.4 months in patients with residual AF vs 37.06 months in
patients free from AF, P ? .03) and type of AF (freedom
from AF is 80% for continuous vs 100% for intermittent, P
The surgical Cox maze procedure remains the gold standard
for AF ablation, with freedom from AF ranging from 80%
to 97.5% over the long term in the 3 main series.7,24,25A
major cardiac procedure to treat a functional condition, such
as AF, it has not been widely adopted.
Over the past several years, the surgical treatment of AF
has evolved rapidly, and a number of devices with various
energy sources have been used to create linear lesions in the
atria (endocardial, epicardial, or combined). These therapies
have been used for both lone AF and AF associated with
structural heart disease.11-16They have been used to repli-
cate some or all of the lesions of the original Cox maze
procedure and have evolved into something of a hybrid
maze procedure that might or might not include the right-
sided lesions of the original procedure (Table 4).7,11-16,24-27
The goal of these techniques, however, is to create lines of
intra-atrial conduction block that will (1) preclude the de-
velopment of macroreentrant circuits in the atria, (2) isolate
the trigger or triggers for AF in or near the pulmonary vein
orifices, or (3) accomplish both goals 1 and 2, while at the
same time allowing the atria to resume either a sinus or
atrially paced rhythm. Recent clinical evidence has clearly
demonstrated that the key mandatory step in the interven-
tional treatment of AF is isolation of the pulmonary vein
orifices.10-18Although this was a part of the original Cox
maze procedure, that portion of the procedure was not
designed specifically to isolate AF triggers because they
were unknown at the time the Cox maze procedure was
conceived and first applied.5,6On the contrary, since Hais-
saguerre and colleagues’ seminal article was published in
1998,8virtually all subsequent lesion patterns have included
isolation of the pulmonary veins.
The main advantages of HIFU over available energy
sources are to provide an energy source and a method to
create rapidly and off pump a reproducibly continuous and
transmural lesion around the left atrium. The technology has
been developed for non-blood–contacting cardiac tissue
ablation from the epicardium off pump while preserving the
endocardial layer, thus overcoming the challenges faced by
gradient-driven technologies. The specific algorithm used to
deliver acoustic energy backward from the endocardium
creates a transmural lesion throughout the whole range of
thicknesses of the human atrial wall. Although a number of
publications describe epicardial ablation with other technol-
ogies, several steps of those procedures still require cardio-
pulmonary bypass and aortic crossclamp times for better
exposure.14Moreover, epicardial fat does not need to be
dissected away or removed before the ablation (Figure 1).
Importantly, AF ablation was performed in 8 patients in this
series through a minimally invasive approach, as described
in the “Patient population” section. Finally, the unique
Wand design allows for a safe epicardial creation of the
mitral line also on the beating heart. The ability to ablate
TABLE 4. Comparisons between published series of surgical Maze and variants
Author No. of patientsSurgery typeConcomitant surgery
Prasad et al7
Schaff et al25
McCarthy et al24
Sie et al15
Gaynor et al27
Raman et al26
Pasic et al11
Mohr et al13
Williams et al12
Benussi et al14
Knaut et al16
R, Right-sided lesions; L, left-sided lesions.
Ninet et alEvolving Technology
The Journal of Thoracic and Cardiovascular Surgery●Volume 130, Number 3803.e5
tissue surrounding coronary arteries without damaging the
arteries themselves is attributed to the weak interaction
between acoustic energy and blood. Ultrasound is absorbed
about 30 times more strongly in soft tissue than in a low-
viscosity liquid, such as blood. As a result, acoustic energy
heats tissue much more than blood. The high blood flow
through the coronary arteries provides a protective cooling
of the endothelial lining enhanced by the absence of acous-
tic heating of the blood.28
Even though the addition of the mitral line lesion failed
to significantly increase the level of efficacy, it is noticeable
that there was no flutter or left atrial reentry tachycardia at
6 months, even in patients with an isolated encircling lesion.
Left atrial reentry tachycardia is usually explained by per-
sistent gaps in transmurality or continuity of the lesions or
at the mitral isthmus.9,10,15,16,23We can, at this stage, only
speculate that when using HIFU, the operator might be able
to create continuously transmural lesions, to reduce the
width of the mitral isthmus, and to achieve a significant
degree of denervation, as documented repeatedly in our
histology slides (Figure 1).
The disadvantage of the device in its current embodiment
is, during the first few experiences, the perception of a
certain size and rigidity, which both turn out to be very
positive in that this perception does not preclude its use
through a minimally invasive approach. The relative rigidity
allows for a precise setting of the device on the atrial wall
behind both venae cavae, without the risk of sliding toward
the pulmonary veins or twisting onto itself.
Recently, the use of additional right-sided lesions has
been investigated by using monopolar15,24or bipolar25ra-
diofrequency, either as an adjunct to the traditional surgical
maze procedure to replace some of the surgical lines (hybrid
maze) or as an isolated procedure (Table 4). Freedom from
AF ranged from 73% in long-term survivors to 90% and
91% at 6 months with a complete lesion set, including
bilateral appendage resection, right-sided lesions, and ad-
junctive cryotherapy.25In this latter report, AF was parox-
ysmal in 63% of the patients, and along with the extensive
lesion set, this might have played a role in achieving the
excellent results. However, the 6-month follow-up in 2
reports24,25was limited to a fraction (50%) of the population
under study (Table 4), and the procedure was performed
during cardiopulmonary bypass and an additional aortic
crossclamp time of 20 to 40 minutes.
Perhaps the only way to compare the results of this
preliminary study with those in the literature is to perform a
meta-analysis of the reports in which thermal lesions were
performed exclusively in the left side of the heart during
concomitant cardiac surgery. Although the lack of standard-
ization in the reporting of events and results makes accurate
comparisons difficult, freedom from AF at 6 months in these
reported series ranges from 65% to 92% (Table 4) using
either various types of radiofrequency or microwave abla-
tion. However, except for a study reporting on a limited
number of patients treated during a fully beating-heart epi-
cardial procedure and an incomplete follow-up,29current
ablation technology still requires significant additional car-
diopulmonary bypass and aortic crossclamp times, as well
as the dissection of fat when some epicardial lines are
applied, and occasional serious collateral damage can still
Finally, the presence of thromboembolic complications
raises the question of their prevention through exclusion of
the left atrial appendage. The incidence of thromboembolic
events after valvular surgery in this age group remains
significant,21and the majority of patients in this report had
mechanical valve replacements. At the time of the writing of
the protocol, there were no studies justifying clearly the
exclusion of the appendage over abstention or the advantage
of an exclusion technique over another, so that the steering
committee did not give a specific recommendation.
The limitations of this study are inherent in a report on
the first clinical use of any technology, particularly the short
follow-up period, although it was completed, with no pa-
tients lost to follow-up. Further studies will be required to
assess the need for a full epicardial lesion set of the Cox
maze procedure, the importance of the mitral line, the
results in patients with lone AF, and the development of
more minimally invasive approaches.
The contribution of the following surgeons, who participated
directly in the study by training and enrolling their patients, is
Figure 1. Histology section of bovine left atrial wall after acute
ablation (Trichrome Masson staining). A fully transmural lesion
(in blue) from the endocardium to the epicardium through a 10- to
12-mm wall total thickness, including 7 to 9 mm of fat tissue, is
Evolving Technology Ninet et al
803.e6The Journal of Thoracic and Cardiovascular Surgery●September 2005
greatly appreciated: Drs E. Choucroun, N. Elia, J.-P. Guibaud, N.
Laborde, L. Labrousse, F. Madonna, and J.-F. Obadia.
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Ninet et alEvolving Technology
The Journal of Thoracic and Cardiovascular Surgery●Volume 130, Number 3 803.e7
Figure E1. Picture of the UltraCinch, which is an array of 8 to 14 ultrasonic transducers with 2 color-coded sutures Download full-text
at each end of the device used to secure it into position around the left atrial wall with a pair of tourniquets.
Figure E2. Focused ultrasound energy originating from the concave transducer and visualized through a Schlerein
effect (fluid-phase laser illumination to visualize the ultrasonic beam). The beam converges at the focal distance
and dissipates beyond that point. The focal distance is fixed and determined only by the radius of the curvature
of the transducer.
Evolving Technology Ninet et al
803.e8 The Journal of Thoracic and Cardiovascular Surgery●September 2005