Keywords
heart valve surgery - congenital heart disease - CHD - tricuspid valve
Introduction
With an incidence of 5.2 per 100,000 live births, Ebstein's anomaly accounts for 1%
of all congenital heart disease.[1] Its main features are a pathologic configuration and attachment of the tricuspid
leaflets that lead to severe insufficiency of the tricuspid valve and a pathologic
configuration of the right ventricle. Additionally, an atrial septal defect (ASD)
or a persistent foramen ovale (PFO) is present in two-thirds of patients,[2] and cyanosis may develop due to interatrial right to left shunting. The onset of
symptoms varies according to the severity of the disease. Some patients become symptomatic
as neonates, others as young adults, and some remain free of symptoms until seniority.[3]
The anomaly is named after the pathologist, Wilhelm Ebstein, who first described it
in 1866.[4] A long time passed until the diagnosis could be made during lifetime in 1951, using
cardiac catheterization.[5] Since around 1980, echocardiography simplifies detection and has become the standard
method for diagnosis. The first surgical procedures in patients with Ebstein's disease
were ASD closures in cyanotic patients, performed in 1956. The mortality of these
procedures exceeded 80%.[6] Since the results of isolated ASD closure were poor, physicians searched for ways
to reduce the insufficiency of the aberrant valve. In 1956, the American surgeons,
Lillehei and Hunter, planned to perform an ASD closure combined with tricuspid valve
repair in a 10-year-old girl with Ebstein's anomaly suffering from severe cyanosis.[7] Due to the progressed heart disease, the patient died upon the induction of anesthesia.
The two surgeons performed an autopsy and developed the first concept to repair the
Ebstein valve anomaly. Later, this concept was successfully applied by Hardy, who
performed the first successful repair of an Ebstein valve in 1963.[8] One year earlier, the first valve replacement in a patient with Ebstein's disease
was performed by Barnard in South Africa.[9] Both repair and replacement of the tricuspid valve will be discussed in the section,
“Surgical Techniques.”
Pathologic Anatomy and Pathophysiology
Pathologic Anatomy and Pathophysiology
Leaflets
The tricuspid valve develops by delamination of the leaflets from the underlying myocardium.[10] In a healthy individual, the three leaflets (anterior, posterior, and septal) separate
completely from the myocardium and their hinge point is located at the tricuspid annulus.
In Ebstein's anomaly, the delamination process is incomplete and does not reach the
tricuspid annulus. As a result, the leaflets are shortened and their hinge point lies
inside the ventricle. The three leaflets are not uniformly affected. The septal and
the posterior leaflets are displaced, and the highest degree of displacement is usually
present at the internal crux of the heart, at the commissure between the two leaflets.
The septal leaflet is small or even rudimentary. The anterior leaflet is usually not
displaced and is enlarged rather than shortened. The displacement of the septal and
posterior leaflets results in a rotation of the valve toward the outflow tract[11] ([Fig. 1]). Various degrees of connections with the myocardium are present at all leaflets,
leading to their restriction. Often, there are holes in the leaflets that contribute
to the insufficiency. The leaflets may have a free edge and chordae tendineae, but
in some severe cases, the edge is directly connected to the myocardium and the papillary
muscle.
Fig. 1 Rotation of the functional tricuspid annulus toward the outflow tract. aRV, atrialized
right ventricle; fRV, functional right ventricle; RA, right atrium.
Ventricle and Myocardium
At the atrioventricular groove, the true tricuspid annulus can still be identified.[11] Due to the partial displacement of the valve toward the apex, the part of the right
ventricle (RV) between the true and the anatomical tricuspid annulus becomes functionally
a part of the atrium and is referred to as the “atrialized ventricle.” The tricuspid
annulus is severely enlarged, as well as the right atrium and the RV ([Fig. 2]). However, the functional RV is small compared with the gigantic right atrium and
the atrialized ventricle. The volume of the entire RV, measured in magnetic resonance
imaging, is two to three times larger compared with a normal RV.[12]
[13]
Fig. 2 Preoperative picture of a 61-year-old man with Ebstein's anomaly. The heart–thorax
coefficient is 0.76.
The myocardium is altered at different sides. At the atrialized RV, the myocardium
is usually thin or even absent. The wall thickness of the functional RV may be enlarged
or thinned.[14] At the left ventricular wall, an increase of interstitial fibrosis may be found.[15]
[16] It is assumed that these alterations contribute to ventricular dysfunction and heart
failure in Ebstein's disease.
ASD
In two-thirds of patients with Ebstein's anomaly, an ASD II/PFO is present. If the
right atrial pressure is elevated, as typically during exercise, a right to left shunt
through the ASD II ensues. Oxygen saturation of the arterial blood is usually moderately
impaired (80–90% saturation).[17] The right to left shunt on the atrial level may also account for paradoxical emboli.
A quarter of patients beyond 40 years of age exhibit a history of an event potentially
caused by paradoxical emboli, such as stroke, transient ischemic attack, brain abscess,
or myocardial infarction.[18]
Rhythm
Patients with Ebstein's anomaly may present with different forms of arrhythmia. In
one-third of the patients with tachycardia, one or more accessory pathways are present,
usually at the posterolateral side of the RV.[19] The enlarged atrium is susceptible for atrial flutter or fibrillation. [Table 1] provides an overview of the most common rhythm disorder in patients with Ebstein's
anomaly. A potentially dangerous combination is the presence of an accessory pathway
and the occurrence of a supraventricular tachycardia. The accessory pathway may conduct
the supraventricular tachycardia in a 1:1 ratio to the ventricle. Accordingly, an
atrial fibrillation may transform into ventricular fibrillation and result in sudden
cardiac death.[20] In patients with mild leaflet displacement, arrhythmia may be the most important
symptom, and even sudden cardiac death has been reported in such patients.[21]
Table 1
Mechanism of tachycardia in patients with Ebstein's anomaly
|
Primary
|
|
|
Accessory pathways
|
Bidirectional (WPW)
|
|
Mahaim fibers
|
|
Other
|
AV nodal reentrant tachycardia
|
|
Secondary
|
|
|
Atrial reentry tachycardia
|
Origin at atriotomy scar
|
|
Atrial flutter
|
Cavo-tricupsid isthmus dependent
|
|
Atrial dilatation
|
|
Atrial fibrosis
|
|
Atrial fibrillation
|
Atrial dilatation
|
|
Atrial fibrosis
|
Abbreviation: AV, atrioventricular; WPW, Wolff-Parkinson-White Syndrome.
Indication for Surgery
The natural history of Ebstein's anomaly depends on the degree of tricuspid valve
dysplasia. In 2000, Attie reported on 72 adult patients who had not received operative
treatment.[22] After 20 years of follow-up, survival was less than 10% in patients with a severe
displacement of the septal leaflet (n = 14), 30% in patients with a mediocre displacement (n = 35), and 90% in patients with only minor displacement (n = 23), respectively.
In contrast, long-term survival 20 years after the surgery is reported to be 70 to
90%.[23]
[24]
[25] Thus, surgical treatment of the tricuspid valve regurgitation improves long-term
outcome. Because both surgical risk and long-term mortality are increased for patients
with advanced disease, surgery should not be delayed.[24] Patients with severe regurgitation beyond 40 years of age should be carefully evaluated
with regard to long-term sequelae of congestion, in particular renal, pulmonary, and
hepatic failure. Severe left ventricular dysfunction is a risk factor for operative
mortality, but it is not a contraindication for surgery. After surgery, left ventricular
function usually improves.[26]
Surgical Technique: Repair
Surgical Technique: Repair
Surgical Access
The chest is opened through a median sternotomy. Pericardial traction sutures are
placed, and after administration of heparin, the aorta and the caval veins are cannulated.
The cannula in the superior caval vein should be placed more cranially, because in
selected cases, a cavopulmonary connection might be needed to unload the RV permanently.
The operation is performed under cardiopulmonary bypass with mild hypothermia on the
cardioplegic arrested heart. Several traction sutures are placed at the right atrium
to provide a perfect exposure of the valve ([Fig. 3]).
Fig. 3 Intraoperative inspection of the tricuspid valve. Green, anterior leaflet; yellow,
posterior leaflet; blue, septal leaflet. The septal leaflet is severely displaced
from the true annulus, the posterior leaflet is almost immobilized by adhesions toward
the posterior wall.
Plication Techniques
The understanding of the plication techniques of the ventricular wall is a key point
for the understanding of the different repair techniques. The size of the RV is reduced
by folding the wall of the atrialized ventricle.
-
The horizontal or transversal plication is intended to reduce the true tricuspid annulus.
-
The longitudinal plication creates a fold from the tricuspid valve annulus toward
the apex, thereby reducing the size of the annulus as well as of the atrialized ventricle.
Ventricular plication bears the risk for coronary artery injury. Therefore, the coronary
branches are continuously followed from the epicardium during plication.
Hunter–Lillehei–Hardy Technique
The first concept to repair the Ebstein valve was developed by Hunter and Lillehei.[7] Their goal was to “reestablish” the physiologic anatomy of the tricuspid valve by
bringing the downward displaced septal and posterior leaflet to the “true” annulus
without detaching the leaflets. This was achieved by plication of the RV in the horizontal
(transverse) plane, i.e., in parallel to the tricuspid annulus. Stiches are placed
from the base of the septal/posterior leaflet to the corresponding place at the true
annulus. After tiding the sutures, the atrialized ventricle is excluded.
Danielson Technique
The Danielson technique[27] is a modification of the Hardy technique. Danielson reasonably describes that the
septal part of the atrialized ventricle is not suitable for plication, because a plication
may affect mitral valve function, and the septum may bulge into the left ventricle.
Consequently, the septal part is still not covered with leaflet tissue after plication.
Therefore, an annular plication at the posterior part of the right ventricle is added.
This brings the anterior leaflet toward the septum and may enhance the coaptation.
This repair technique results functionally in a monocuspid valve since the posterior
leaflet is almost excluded by the posterior ring plication and the septal leaflet
remains as a remnant below the coaptation plane.
Carpentier Technique
The plication techniques for the repair of the Ebstein valve addressed the wrong target;
the techniques addressed the ventricle instead of the leaflets. The leaflets of the
Ebstein valve are “trapped” by multiple attachments, which prevent sufficient coaptation
regardless of how much the ventricle is distorted by plication. As early as 1958,
Lillehei and Hunter stated in their paper that the plication method was favored because
of its relative ease of use but that a repositioning of the leaflets would be the
more physiologic approach: “This plication maneuver would appear simpler, quicker,
and more feasible than the previously considered procedure of cutting the leaflets
free and reattaching them in a more normal position.”[7] Surgical techniques, suture material, cardiopulmonary bypass, and even cardioplegic
arrest were not developed enough to allow for complicated reconstructions at that
time.
Alain Carpentier with his ingenious and structured surgical imagination was the first
to address the leaflets for reconstruction of the Ebstein valve.[28] Carpentier described the disconnection of parts of the anterior and the posterior
leaflet from the functional annulus at the hinge point, thereby gaining access to
the multiple attachments behind the leaflets that prevent leaflet mobility. By dissection
of these attachments, the whole leaflet tissue becomes available for repair. However,
the chordae tendineae stay in place. Then, the RV and the true tricuspid annulus are
reduced by performing a longitudinal plication of the posterior wall. The previously
disconnected leaflets are rotated clockwise and reattached at the true tricuspid valve
annulus. The anterior and posterior leaflets now act as a bicuspid valve at the height
of the true tricuspid annulus. In adult patients, the annulus is enforced with a ring.
Cone Technique
The cone procedure developed out of the Carpentier repair.[29] However, Da Silva's cone technique takes the severe downward displacement of the
septal and part of the posterior leaflet more into consideration. With Carpentier's
technique, where the valve is reconstructed in a “horizontal” plane, some of the displaced
leaflet tissue is lost for repair. In contrast, the “cone valve” is not reconstructed
in a “horizontal” plane but in the shape of a cone, predetermined by the Ebstein morphology.
Together with the posterior leaflet and the displaced part of the anterior leaflet,
the septal leaflet is dissected free and mobilized extensively ([Fig. 4a]–[b]). Parts of the septal leaflet are adherent to the ventricular wall and have to be
“peeled off” the myocardium. For each leaflet, a chordae tendineae or a corresponding
ventricular anchoring is retained. Similar to the Carpentier repair, a longitudinal
plication is performed, reducing the size of the ventricle and true tricuspid annulus
([Fig. 4c]–[d]). The true tricuspid annulus is further reduced by annular plication to a size that
all three leaflets cover the full circumference of the annulus ([Fig. 4e]–[h]). The leaflets are longitudinally attached to each other with a running suture such
that the valve, which initially consisted of three separate leaflets is transformed
into a valve with a single circular, cone-shaped leaflet, covering 360 degrees of
the true tricuspid annulus. Even though the annulus is reduced extensively and the
commissures are closed, there is usually no gradient over the newly created “cone-valve.”
Fig. 4 (a–h) The cone procedure, step by step.
There are numerous modifications of the cone technique, including leaflet augmentation,
ring annuloplasty, usage of autologous or artificial chordae, and the Sebening stitch.[30] However, in our experience, the consequent application of the originally described
cone technique alone is sufficient for successful valve construction in the majority
of patients.[13]
Wu Technique
Mobilization of the leaflets and reinsertion at the tricuspid annulus are performed
in the same way as in the Carpentier repair.[31]
[32]
[33] However, instead of a plication, Wu advocates a resection of a triangular piece
of the posterior part of the atrialized ventricle. Wu further describes the use of
autologous pericardium if sufficient septal tissue is missing.[32]
Hetzer Technique
Hetzer describes various techniques for Ebstein's repair.[25]
[34] Their key feature is annular plication. The posterior part of the tricuspid annulus
is connected to the septal part of the tricuspid annulus. In some cases, Hetzer suggested
the creation of a double orifice annulus. By approaching two points at the opposite
side of the true annulus (septal and anteposterior), two orifices are created. The
RV is not plicated and the thin myocardium of the atrialized ventricle remains in
the RV. The leaflets are not mobilized.
Sebening Stitch
The Sebening stitch transfers the chordal attachment of the papillary muscle of the
anterior leaflet to the septum close to the “true” annulus. This procedure creates
a monocusp valve because the posterior and the septal leaflet are both excluded. The
anterior leaflet, which is usually fairly mobile, coapts with the septal rim of the
“true” annulus. Although the Sebening stitch alone may result in a sufficient tricuspid
valve,[35]
[36] nowadays, it is mostly performed as an additional measure in combination with other
repair techniques.[30]
[37]
[38]
Surgical Technique: Replacement
Surgical Technique: Replacement
The prosthesis is placed at the height of the true tricuspid annulus. A horizontal
plication of the annulus is usually required. To avoid damage to the atrioventricular
(AV) node, some surgeons suggest to place the septal suture line in front of the coronary
sinus, thus draining the coronary sinus into the right ventricle.[23]
[39] The valve tissue may be removed or left in place.[39] Tissue near the outflow tract can cause obstruction and should be removed.[23] On the posterolateral aspect, the tissue is very thin and the suture line should
therefore be deviated toward the atrium to avoid coronary artery injury.[23] In addition to the valve replacement, the atrialized ventricular myocardium should
be reduced by plication.[40]
Surgical Technique: Further Considerations
Surgical Technique: Further Considerations
ASD Closure
ASD closure is recommended by the current guidelines of the European and American
Society of Cardiology.[41]
[42] Usually, a direct suture is sufficient for the ASD closure. To prevent RV failure,
a residual interatrial shunt may be left. In case of RV failure, right atrial pressure
increases and a right to left atrial shunt unloads the RV.[13]
[29]
[43] We recommend to leave a 5 mm ASD in all patients treated with the cone procedure.
If the residual shunt later leads to exercise intolerance and cyanosis, the ASD may
be closed interventionally, but most patients remain free of any symptoms.[13]
[29] A potential drawback of the residual interatrial shunt is the remaining risk of
paradoxical embolism.
Antiarrhythmic Strategy
Some studies suggest that after tricuspid valve repair without concomitant antiarrhythmic
surgery, two-thirds of patients who initially present with arrhythmias remain free
of symptoms in the follow-up.[44]
[45] Nevertheless, concomitant antiarrhythmic surgery should be considered.[46] Antiarrhythmic surgical procedures may be divided into (1) procedures for accessory
pathways or AV-nodal reentry tachycardia and (2) procedures for atrial fibrillation
or flutter.
Procedures for accessory pathways or AV-nodal reentry tachycardia have lost their
significance due to catheter ablation techniques. The intraoperative mapping and dissection
of those pathways was initially introduced by Sealy and coworkers in 1963.[47] This procedure has nowadays become a rarity, because patients usually undergo catheter
ablation prior to cardiac surgery. Similarly, slow-pathway ablation for AV-nodal reentry
tachycardia is usually performed by catheter. Nevertheless, Bockeria and coworkers
reported in 2005 that intracardial mapping and ablation accessory pathways had a higher
success rate than the transcatheter ablation in patients with Ebstein's anomaly.[48]
In contrast to the abandoned surgical procedures for accessory pathways, the maze
procedure for atrial flutter is a current and successful antiarrhythmic surgical procedure.
The placement of a set of ablation lines creates a maze for the electrical activation
on the atrial wall. Instead of a planar propagation, the electrical activity propagates
inside numerous blind-ending paths. Thus a (macro-) electrical circuit resulting in
atrial fibrillation of flutter is prevented.[49] Both a maze limited to the right side and biatrial maze are applied successfully
in patients with Ebstein's anomaly, with a success rate of 93%.[50] Some surgeons recommend the addition of a cavotricuspid ablation line even in patients
without previous arrhythmia to prevent isthmus-dependent flutter.[50]
Bailout in Case of Right Heart Failure
Cardiac decompensation due to impaired RV function is a major concern after tricuspid
valve surgery for Ebstein's disease, since afterload may be increased by the competency
of the tricuspid valve when the blood is ejected only into the pulmonary artery. Consequently,
RV stroke volume and ejection fraction decrease. On the other hand, volume load, i.e.,
preload of the right ventricle is also reduced and in most cases, may compensate for
the increase in the afterload. In the early postoperative phase, beginning with weaning
from the heart lung machine, the risk for RV failure is high.[13] A temporary solution is to unload the RV by extracorporal membrane oxygenation (ECMO)
in the postoperative phase.[13] A permanent solution is the creation of a bidirectional cavopulmonary anastomosis
(Glenn anastomosis). This “one and a half ventricle repair” can only be performed
if pulmonary artery pressure is not elevated.[51]
[52] In patients with a 1.5 ventricle repair, the flow over the tricuspid valve is diminished,
and a mechanical prosthesis should be avoided due to increased risk of thrombosis.[53]
Results after Surgery
[Table 2] shows the outcomes after different types of surgery in large patient collectives.
Table 2
Long-term outcome after Ebstein's repair or replacement
|
Publication
|
Technique
|
Patients
|
Mortality
|
Reoperations
|
|
Brown et al[23]
|
Replacement
|
378
|
6% early, 17% after 10 years
|
41% after 20 years
|
|
Brown et al[23]
|
Danielson
|
182
|
5% early, 12% after 10 years
|
36% after 20 years
|
|
Badiu et al[24]
|
Sebening
|
130
|
2.6% early, 13% after 10 years
|
38% after 20 years
|
|
Hetzer et al[25]
|
Hetzer
|
68
|
2.4% early, 8.7% after 10 years
|
7.1% after 20 years
|
|
Chavaud et al[57]
|
Carpentier
|
91
|
9% early, 13% after 10 years
|
11% after 20 years
|
|
da-Silva et al[29]
|
Cone
|
52
|
3.8% early, 14% after 7 years
|
4 reoperations
|
Repair versus Replacement
In a single-center study from the Mayo Clinic, Brown and coworkers found no difference
in survival following replacement and repair (Danielson technique).[23] In patients below 12 years of age, freedom from reoperation was lower after repair
than after replacement. There was no difference in freedom from reoperation in patients
over 12 year of age (80% after 10 years). Today, repair is generally considered as
the first-line treatment.
Replacement: Biological versus Mechanical
In a recent retrospective study, Brown and coworkers reported similar rates of reoperation
after implantation of a mechanical or biological prosthesis in patients with Ebstein's
disease. However, survival was longer after the implantation of a biological prosthesis.[54] An important limitation of this study is that age was significantly higher in patients
undergoing replacement with a mechanical device. Furthermore, 69% of the mechanical
valves were ball and cage prostheses, which meanwhile have been replaced by bileaflet
valves. Barlett and coworkers performed a retrospective multicenter study including
children below 6 years of age undergoing tricuspid valve repair. While there was no
significant difference in survival after replacement using a mechanical or biological
prosthesis, the use of a mechanical prosthesis was associated with a higher rate of
failure (twofold) and a higher risk for pacemaker implantation (13-fold).[55] Generally, a biological prosthesis should be recommended independent of the age
of the patient. These prostheses may become dysfunctional early, especially in patients
younger than 16 years of age, but a redooperation can be performed with a low mortality.[56]
Some authors suggest that due to the low opening and low closing pressure at the tricuspid
position, porcine bioprostheses are more suitable compared with pericardial bioprostheses
because of their thinner leaflet tissue.[53]
Types of Repair
Till date, no comparative study among different types of repair has been performed.
Both the Mayo Clinic (2008, Danielson technique)[23] and the German Heart Centre Munich (2010, predominantly Sebening stitch)[24] reported an excellent early and long-term survival after repair but considerable
rate of reoperation in the long-term follow-up (36 and 38% reoperation after 20 years).
In contrast, the group of the Hospital George Pompidou, Paris (2003, Carpentier technique)[57] reported considerably less reoperations in the long-term follow-up than the other
two groups. Likewise, the percentage of repair procedures (98%) was higher compared
with the German Heart Centre (90%) or the Mayo Clinic (34%). In 2007, the group of
the Hospital Beneficencia Portuguesa, Sao Paolo (cone technique) reported an excellent
survival and few need for reoperation[29] in 40 consecutive patients with Ebstein's anomaly.
In consequence of the excellent results from the group in Sao Paolo with the cone
repair, many groups with an extensive experience in the repair of Ebstein's anomaly
such as the Mayo Clinic in Rochester,[30] the German Heart Centre in Munich,[13] the great Ormond Street Hospital for Sick Children in London,[58] and the Children's Hospital in Boston[59] switched to this technique. Furthermore, the cone technique was adopted by the two
highly frequented hospitals—West China Hospital, Chengdu[60] and the Shanghai Children's Medical Center.[61] It is noteworthy that the favorable results with regard to mortality, valve competency,
and the high percentage of achieved repair could be reproduced by all of these groups.
Furthermore, MRI measurements show a major change in RV size and shape after the cone
repair. At the German Heart Centre, the preoperatively indexed end-diastolic volume
of the functional RV was 191 mL2 (normal value: 75 mL/m2) and was reduced to 123 mL/m2 6 months after the repair. The group of Chengdu reported similar results (index preoperative
RV end-diastolic volume: 134 mL/m2 reduced to 97 mL/m2 postoperatively). According to the law of Laplace, a reduction of RV diameter results
in a reduction in wall stress. Thus, there is a good reason to assume that the cone
repair may prevent a later heart failure. The RV ejection fraction remains impaired
in the midterm follow-up, but the regurgitation volume decreases. The net result is
an increased flow over the pulmonary artery[13] and an improved left ventricular filling.[58] Cardiopulmonary exercise testing displays an improved functional status in the midterm
follow-up after the cone repair.
Special Case: Newborn
Pathology
During the first weeks of life, a newborn with Ebstein's disease may present with
an aggravated physiologic condition. Right ventricular function is impaired by the
presence of severe tricuspid valve insufficiency. At the same time, the pulmonary
pressure is physiologically elevated, putting additional stress on the RV. In this
situation, severe congestive failure may evolve rapidly and the patients may have
to be assigned to surgery in the neonatal period. However, in some cases, symptoms
may diminish with the physiologic decline in pulmonary artery pressure. The therapeutic
goal in severe neonatal Ebstein anomaly is not “earliest surgery,” but medical management
including measures to reduce the pulmonary vascular resistance (even with prostaglandin
infusion in the beginning). When weaning from prostaglandin E fails, it serves as
an indication for an early surgery. Celermajer and coworkers developed an echocardiographic
score (Great Ormond Street Echo score, GOSE score) to help the physicians in this
situation to decide between an early surgery or medical treatment until later repair[61] ([Fig. 5]).
Fig. 5 Calculation of the Great Ormond Street Echo Score according to Celermejer et al,
1992. aRV, atrialized right ventricle; fRV, functional right ventricle; LA, left atrium;
LV, left ventricle; RA, right atrium.
Accordingly, the disease can be graduated, and a mortality risk can be determined
([Table 3]).
Table 3
Survival rates of neonates with Ebstein's anomaly
|
Score
|
|
Natural course
|
|
<0.5
|
GOSE I
|
0% Mortality
|
|
0.5–0.99
|
GOSE II
|
10% Mortality
|
|
1–1.49
|
GOSE III
|
44% Mortality
|
|
≥1.5
|
GOSE IV
|
100% Mortality
|
Abbreviation: GOSE, Great Ormond Street Echo.
Palliation: Starnes Procedure
The first series on successful palliative surgery in neonatal patients with Ebstein's
disease was published in 1991 by Starnes.[62] In this procedure, the tricuspid valve orifice is closed with a membrane at the
true tricuspid annulus and the pulmonary artery is ligated. An atrioseptectomy and
a modified Blalock–Taussig shunt are added.
A certain amount of blood still drains into the RV via the perforant veins. In a later
experience of the Starnes group (16 patients), the importance of leaving a small hole
in the membrane was emphasized to decompress the RV.[63]
[64] This improved survival after a mean follow-up of 27 months from 66 to 80%.
Correction: Knott–Craig
In 2000, Knott Craig and coworkers published three cases of neonates with Ebstein's
anomaly undergoing repair of the tricuspid valve.[65] GOSE-scores were 1.3, 1.8, and 2.4 with a high probability of death without surgery.[61] The authors created a monocuspid valve consisting of the anterior leaflet only and
added a bidirectional cavopulmonary anastomosis. An annular plication was performed
by placing a suture with one pledgeted end at the anterior–posterior commissure and
the other pledgeted end at the coronary sinus. By connecting these two points, the
annulus is divided into a bigger orifice (containing the anterior valve and part of
the remnants of the septal valve) and a smaller orifice at the posterior wall (containing
the posterior valve). The smaller orifice is closed by a running suture. At the bigger
orifice, the anterior leaflet can coapt with the septum and act as a monocuspid valve.
As a further modification, the septal leaflet may be detached at the annulus if the
anterior leaflet is adherent and therefore not able to coapt with the septal wall.[66] At the place of the detachment, a patch is inserted to enlarge the anterior leaflet.
In 2011, the group of Knott–Craig reported 32 neonates and young children, of which
90% underwent biventricular repair. GOSE score was ≥ 1 in all patients and ≥ 1.5 in
22 patients. Early mortality was 22% and there was one late death.[67] Freedom from reoperation after 15 years was 75% in patients undergoing biventricular
repair.
Recently, most centers with extensive experience with the cone procedure have also
started to apply this technique in newborn children if there is enough valve tissue
for the reconstruction. Since it is still a preliminary experience, this information
is based on personal communication only.
Conclusion
Surgical repair of Ebstein's anomaly has been a challenge for decades. Since the first
description by Hunter and Lillehei in 1957, many different repair techniques have
evolved. Plication procedures alone yielded acceptable results but were characterized
by a considerable reoperation rate. With the advent of complex leaflet reconstruction
techniques, such as the Carpentier and the cone reconstruction, a more physiologic
repair became available. In particular, the cone reconstruction shows very promising
results and may become the technique of choice for patients with Ebstein's anomaly.
