Mavroudis Ebstein's Anomaly

Ebstein's Anomaly Mav28

-failure of delamination of the inner layers of the inlet zone of RV to form the TV tensor apparatus and TV leaflets, also failure of endocardial cushions which contribute

--> TV septal and posterior leaflets are displaced apically to the jct of the inlet and trabecular RV parts

Path

-TV leaflet adhered to myocardium (=failure to delaminate)

-downward/apical displaced fx'l annulus (septal >post>ant)

-atrialized part of RV w hypertrophy and thinning of the wall

-redundant, fenestrated tethered ant TV leaflet

-dilated R AV jct (at the true TV annulus)

-septal leaflet most affected, ant leaflet least affected

-TV leaflets bizarre, dysplastic, tethered by short cords and paps, and attached to the muscular band

-The TV ant leaflet may be so deformed that it is displaced into the RVOT (blocks RVOT)

-Rarely, get imperf TV

-In less severe pts, ant leaflet may be sail-like curtain in the RV. It has a free leading edge, which is key for the repair. The free edge is mobile, w hyphenated attchmts = focal, segmental, direct attchmts to the underlying myocardium, or may have linear direct attchmts = entire leading edge attached to the endocardium

-Without a free leading edge, repair will not be good

-Atrialized part of RV is thin and dilated.

-Entire RV (RA part and RV part) is dilated

-AV Nd is in Koch triangle apex, and conduction usually Nl

-ASD is common assoc

-ccTGA commonly assoc; (w the TV systemic)

-in these cases, the TV ant leaflet is smaller and differently shaped

-AV conduction tissue in ccTGA is on R side and anterior, at a distance fr the L sided morphologically TV...

-decr forward Q bc of signify TR and impaired RV fx, also during atrial systole the atrialized RV which is thin balloons out bc it is in diastole..., so hinders RV filling

-usually an ASD/PFO allows R to L shunting or L to R shunting...

==> huge RA --> worsens the TR --> enlarge the PFO/ASD

-older pts get hypertrophied RA wall too

-atrial tachy common in older pts bc of the big RA

-15% have WPW, 1-2% have AVNRT

-VT/VF common at end stage HF

Sx

-die fr HF, hypoxia, arrhythmia, sudden death

-ref 14-15 - if dx as infant, --> worse Px, w 1/3-1/2 dead by 2yo

-ref 15- if dx in utero, Px is even worse

-Sx d/o apt of TR, presence of ASD, RV dysfx, assoc xx

-high PVR worsens the TR as a neonate; the TR can --> R to L at ASD w much cyanosis; if pt survives this pd, the cyanosis improves as PVR drops...

-Older pt- early fatigue, dyspnea, exertion, cyanosis, palpitations fr PACs/PVCs, eventually ascites/preiph edema

-ref 14- NHx- 67 pts, 12 yr f/u mean, 39% NYHA I-II, 61% II-IV

-death in 21% of pts who had either NYHA3-4, CT ratio >0.65, cyanosis to SaO2 <90%, or Dx as infant

-soft heart sounds, many murmurs, systolic TR murmur at LLSB, low intensity diastolic and pre systolic murmur fr the fx'l TS, louder w insp'n.

-arterial and jugular venous pulse Nl, large V wave fr jugular vn pulse is uncommonly present

-liver may be big, but not usually pulsatile

Dx

-echo

-...

Tx

-Neonate- Tx phtn if present w O2/NO

-Rx Tx limited in older pts- diuretics as needed, arrhyth Tx as needed

-initial surgical palliation in 1950s were syst to pulm shunts for pts who couldn't generate Qp (imperf TV, blocked RVOT, subpulm hypertrophy etc). If they don't have an obstruction, then a syst to pulm arterial shunt won't help, and have been fatal instead

-Classic Glenn- SVC to RPA - proposed to be more physiologic way to improve SaO2

-but it proved limited for Ebsteins= ref 17 n=36 pts w SVC to PA shunt, 17 survived the operation, only 14 were c/s to have benefited

-1954- ref18- 1st direct heart surgery for Ebsteins- Wright et al - single suture in atrial septum to close the PFO--> pt survives, but residual ASD remained

-1958- ref 20 - Hunter & Lillehei attempt to Tx the vlv- reposition the displaced post and septal leaflets- exclude the atrialized centric chamber --> both got heart block and died

-ref21- Hardy et al modified Hunter's technique and placed interrupted sutures close together on the spiral line of displaced post/sept leaflet--> tied sutures together to create multiple tucks in the leaflet--> narrow TV orifice and pull the leaflets back t the TV annulus - 4/6 pts survived, 1 w complete HB; early results ok, but overall it isn't able to establish a competent TV, and moving the leaflets to the annulus level still leaves the formerly atrialized RV dilated, and one isn't truly able to isolate it completely, so there is still a sac attached to the RV...

-1963- ref 23- TV replaced by Barnard & Schrire in 2 pts- place sutures above the CS to to avoid the AV nd system, but then coronary sinus Q goes to RV, also atrialized part of RV isn't obliterated

-1967-ref20- Lillehei - Starr-Edwards ball valve in 5 pts,2 had complete HB in pts w vlv sutured to the true annulus

-some have tried a prosthetic vlv + ventricular plication (ref 24), and close the ASD (ref25)

-Starns ref 26- rec closing the ASD and the TV with a pericardial patch, and placing an AP shunt--> Single ventricle pathway w a Fontan eventually

-Prosthetic TV is ng bc high complication rate- malfx, thrombosis for mech vlvd (ref 27), limited life expetency for tissue vlv, spec in kids (ref 28)

-Mavroudis 1972- ref 29- plicate atrialzied RV free wall, do post TV annuloplasty, and excise the redundant atrial wall- it uses the ant leaflet of the TV, which is usually enlarged, to construct a mono leaflet vlv

-must have an ant leaflet w at least 1/2 of it without any linear attchmt for best repair

-ref 13, 30 outcome...

-other approaches more recently- ref 31-35

-whether atrialized RV plication/resection is helpful is controversial

-may reduce size of nonfxl RV to help Q thru R heart, reduce compression on LV by RV to improve LV fx, elevate the pap muscles to facilitate closure of the ant leaflet against the septum, and provide more space for lungs.

-however, all internal forms of plication will interrupt some of the coronary Q to RV, and risk to kink RCA

-Mavroudis- repair TV better than replace it, but if there is failure of delimitation of >1/2 the ant leaflet, or if the leading edge of ant leaflet has hyphenated or linear attchmts (=entire ant leaf leading edge is directly attached to RV), then a durable repair might not be possible, so may need to replace the vlv

-Mavr review ref36- 158 pts w bioprosthetic TV replace - freedom replacement 97.5% at 5yr, 81% at 10 yr, and 83% at 15 yrs;

--> bioprosthetics do better in TV than other valves, and despite initial concern for poor durability (Ref 28, 37), maybe bc of the low turbulence at TV position, so less wear and tear on the tissue vlv, so they became more liberal with the TV bioprosth replacement, rather than leaving someone w moderate TR. They use it if less than good to excellent outcome is expected.

-c/s mech vlv in adult pt already on warfarin

Surgical Indications:

-ASx pt without R to L shunting- observe

-if survive infancy, pts generally do well for years, and surgery can be held off till Dx dvp, or paradoxical emboli occur; c/s surg in ASx pt if pt has objective evidence of xx- incr heart size on CXR, progressive RV diln, reduce RV syst fx, PVCs, atrial tachy.

-Once pt gets NYHA 3-4 Sx, Rx Tx is limited, so surgery is indicated

-All pts will eventually show progressive deterioration, all will need surgery eventually

Operative Mgt

1) Electrophysiologic mapping to find APs in pts w pre-excitation

2) Close ASDs

3) Correct prev placed AP shunts, assoc xx (VSD, PS, PDA...)

4) Perform any antiarrhyth procedure needed for APs, cryoablate AVNRT, maze...

5) c/s plication of the atrialized RV

6) Reconstruct TV if possible; otherwise replace

7) R reduction atrioplasty

-EP stuf....

-CP Bypass- aortic and bicaval cannulation w moderate hypothermia (28-34C)

-vent the L heart w a cath via superior P Vn and via an aortic tack vent

-Cross Clamp Ao temporarily to administer carioplegia +/- topical hypothermia

-Open RA fr the appendage to the IVC

-close the ASD, often the atrial septum is thin and dilated, so excise that part before patching close the ASD

-Cardiac arrest during TV repair, w bloodless field

-if TV is replaced, remove the cross-clamp after suture placement in the region cephalad to the conduction tissue, and then allow heart to reperfuse and beat

-Original repair:

-ventric plication sutures placed post-laterally in the atrialzied RV to bring the hinge pt of the displaced TV twd the tricuspid annulus--> elevate the pap muscles of the ant leaflet and allow the leaflet to close against the septum.

-avoid the coronary arteries- RCA and post descending

-more recently, instead of doing an internal plication, bring the ant pap muscle twd the septum

-Post annuloplasty- critical to the procedure

-post part of annulus is first narrowed w annuloplasty suture, and then obliterated by running sutures fr the free wall annulus to the septum

-or, one can approximate the RV free wall part of the TV annulus directly to the ventric septum w pledgeted sutures, then obliterate the rest of the posterior TV annulus w running sutures

-if the ant leaflet has signif xx, then repair won't be as good:

-fenestrated or perforated ant leaflet- need fine running sutures

-small ant leaflet- may --> some tricuspid stenosis w the repair, often tolerable

-if the edge of the ant leaflet isn't fee and mobile, then --> xx

-acchmts of the leading edge to the underlying endocardium or linear attchmts are not good for a TV plasty

-short pap muscles doesnt preclude a good repair if the rest of the leaflet is good

-but, direct insertions of pap muscle head into the leading edge of the ant leaflet --> severe restrict leaflet motion--> hard to repair

-some pts may have enough post leaflet to make a bileaflet repair, rare to be able to have a trileaflet repair

-then, test the TV competency, by injecting saline under pressure into the RV

-often check p off CP bypass, by TEE

--if need to replace TV:

-ensure that the suture line is cephalad to the AV node, His bundle, and membranous septum

-ensure sutuer is ceph and to the TV annulus posteriorlaterally to avoid injuring the RCA; coronary sinus can be left to drain into the RA

-ensure the struts of the prosthesis straddle the area of the membranous septum and conduction tissue

-Then, do a R reduction arterioplasty

-ensure you don't cut the crista terminalis or suture into it, bc an --> a-flutter

-ensure you place pacing wires for postop mgt

-remove part of the anterior pericardium on the R side, bc a postop pericardial effusion is common after Ebsteins's repair- espec if cardiomegaly before

-Neonate- best Tx is debatable

-if iNO fails, then surgery per Mavroudis

-prefer biventricular repair to single ventricle repair (ref 34)) based on their outcomes

Clinical Data

-Mavr data -( ref 30 for 1st 189 pts)- 1972-2001 - 429 pts w Ebsteins underwent surgery

-range 11mo - 64 yrs, median 16 yrs, mean 19 yrs at surg

-assoc xx- ASD, accessory AP, PS, VSD, AVNRT, partial AVCD, absent CS, PAPVR, bilat SVC

-ref 13- recent report of results fr 323 pts- range 9mo - 70 yrs, median 17 yrs,

-43% had TV reconstruction, 55% rosthetic valve, usually bioprosthetic, 2.5% had Fontan

-21 early deaths (6.5%)

-45 had WPW ablation, 14 had maze for a-fib, 8 had AVNRT ablation

-23 late deaths (7.6%)- (max f/u 25 yrs, mean 7 years)

-late echo showed intact AS in all pts, 23 pts (16.7% needed re-op, mean 9.4 yrs leater

--late f/u- less atrial arrhythmia; 92% were reduced to NYHA 1-2

-most pts get reduction in heart size postop

-9 women had successful pregnancies w normal delivery

-ref 42- max exercise testing showed an increase in work performance, exercise duration, amx O2 uptake

-max O2 consumpt incr fr 47% to 72%

-ref 38- R sided maze for atrial arrhythmia in any CHD- n=44, 73% for paroxysmal a-fib, 27% for ch a-fib

-> most pts had Ebstein's (70%) - 1 early death, 1 needed pacer for tachy-brady syndrome

-mean 17 mo f/u, - sinus in 85% of pts, jctl in 6% of pts, a-fib/flutter in 6%, 1 paced

-no late death or re-opeartion