Transesophageal Echocardiographic Monitoring of Interventional Cardiac Catheterization in Children OLIVER

STirMPER.

MD,

ADRI CROMME-DIJKHUIS.

MAARTEN MD.’

WITSENBURG. MICHAEL

MD.’

J. GODMAN,

GEORGE

R. SUTHERLAND.

FRCP.

MD. JOHN HESS, MD*

Erii”hW~h.Srorioridrmd Rorrrrdiim. mr Nvrlirrl‘rridi

‘i’ranscsopbag~~l echocardiograpby wasused prospectively in 21 children schadutcd for interventionst cardiac eatheterizntkn (9 with pulnwnsry vaivuloptasty, 5 with am’tk valvuloplasty, 1 with pulmonary angioplasty, 2 with aortic angioplasly, 2 with paknt ductus arteriosus wxtusion and 3 with hlusrard batik dilation) to determine its ptontiat value as a monitoring kchntgue. The oatisnls ranted in ace from 0.9 to 14.6 rears tmran 5.41 and in &ght from”9.5 to &2 kg (mean 21.1): Studirs were completed in all patients without complkatlons. Preinkrvenlion studies provided imporlanf new information in two patients, leading Lo cancellation of the planned procedure. M@x contributions aftransesophngeal monitoring includedI)a nal time~ssosmml ofcsth~t~r placement across&her atrtovon-

trkutar w&e and the aortk valve during bstlrmn valruloplssty; 2) immediate assessmentalsortie valve and aortk wall morphology during balloon dilation; anA 3) dotalled morphologic and hemo.

Over the past decade. mterventional cardiac catheterization has become an important new therapeutic approach to the treatment of congemlal heart disease in childhood (l-3). Balloon dilation has become the treatment of choice for pulmonary valve stenosis (4-6) and recoarctation of the aorta (7-9). In selected cases. umbrella closure of a patent ductus arteriosus has become an alternative 10 swekal closure (IO,1 I). Clamshell occlusion of atrial or ven&lar sevtal defects has been effected (12.131 and is at wesent the

dyrwnk in~ormatlan together with enhanced &h&r guidance during hlustard b&e dilation. After pulmonary valvuloplasty, parttal chordal rupture of the tricuspid valve was documenkd in we patioa. In two patients, baltoan each&r pailion was modified according to the transe-

of

sophhagesl findings. The assessmed changes io pulmonary valve marpholt-gyand tramcatheter twInsion of a patent ductus atie. rima w&snot enhanced by single-planetransaphsgeat monitor-

ing. Pulsed wave Doppler studks cantrtbukd sdditionpl Informa. lion in the assessmentof immedlak hemodynunk changes after intsrventionsl pracedures. Transesophagmlechowdiigrsphy is B new important guiding snd monitoring techniqueduring interventionptcardt~c catheterizslionpr~edurtsInchildren.IIesn provideadditional realtime

imaging information, hmmdtate identification of wmplicatklr, and awssment cl hemodynamk changer. f, Ant Coil Cwdiol1991;18:1506-14)

cardiac morphology. including the acute changes in vessel wall morphology and valve leaflet structure. is not well demonstrated radionraphicallv. Repeat antigraphy is often impractical during-the procedure. Prec~rd% &sound studies have been used to monitor a variety of cardiac mterventions. including lbe Rashkind balloon atrial seplostomy 114). However, such studies may be cumbersome and intelfere with the procedure. Since the intmduction of single-plane tmnsesophageal echocardiography into pediatric cardiology 2 years ago (ISi7). .* has rapidly gained acceptance as a diagnostic technique in the primary diagnosis of congenital heart disease 18.19) and a perioperauve monitoring technique (20.21) and is useful in the postsurgical follow-up period (22,23). Potent~alty, when used during imerventional cardiac cathererizalion, transesophageal echocardiography would allow for a continuous assessmenl of cardiac morphology and function and thus might be expected to be a valuable on-line monitoring techniquz. However. to date, no study has addressed the question of whether or where transesophageal echocardiographic studies might be helpful in monitoring and guidance over the wide range of interventional procedures currently used in pediatric cardiology.

t

Methods Study patients.

To determine

procedure the value of transe>oph-

ageal echocardiography in the monimrinf and guidance of intervenlional cardiac catheterization in the pedistnc sgc group, 22 children were studied prospecwely Ho,p~l

Each \rudy

v,deor.w

\\a,

recorded

I” I,\ enurery

onto

,mG isxo

P~rticuler morphok+!!

smrntm ks paid LO demonslradng of ;~n\ ohrtrucuve

reldted hsmudyn;tmic changes ailh lechmque\. Studis, were completed

systemic

\I,WC IDoppler umpling

obstructIon

after d Mustard

pro-

cedure (Table IL

partern~. pulmonalg

Trsnsesophngenl echacardiugraphic studies. The audlc, were performed in all children rr!th we of a promrvpe smgle-plane pediatric :rensesophagsal probe iDeparrmem of Experimcnml Echocardmgraphy. Thornwxer. Ratrerddmi interfaced 10 either a Hewlrll-Packxd Sono, 1000 or Toshiba SSH 160 A ullrasound >y\tem The marunal \haft

twn of other reie\ant

diameter

of the probe meawed

7 mm and mwmnl

vene-axis cross-secl~onal Imaging. colur How mappmg and pulsed wave Doppler sampling. The momtor of the uImilsound machme wil, po.moned LO a, ,o pwdc an add,t,onai for Ihe penon performmg

the

culor flow mapping hy selecdvc pulsed

oi a~r~o~emncular ir\V)

venous Rotr pattcm,

valve How

and the interroga-

areas of intercs!. The sample vulumc

tbc pulmonary

veins or at the level of the

up> of the AV rnlve leaflcrs. Recordings were made at paper rpced

of W or IO0 mmls during held mspwation.

~r;tn\-

ducer dimenqlons were ? x IO mm. Steermg Ixililies zrrc restricted to anterior and pwtrriur angalnuon only. The tramesophageal probe allowed forS.MHl. 4%ciemem rraw-

on-line monitor

\~,a plsccd a:thm

fully

lesion and to evaluating the

for aortic angloplasty for recoarcmuon. two for patrnl ductus aneriosus occlusion and lhrec for balloon dilation of venous pathway

of invacardiac

ranged from 0.9 to 14.6 yearr

the cathelerzalion

pccwd finding. Thereafter. the lranresophagesl prohc was \$llhdrawn m il high eaphageal position unlil the lnill~l dnenowc

hemodvnamic

and anmocardwraphic

study WYBF

venti”wl catheter WY achked. comhined‘imagmg and color flow mappinE studies were carried out durmg the enme procedure in an attempt to assess any morphologic and hemudyndmic changcer. Akr terminilti”” of the interveniional procedure. a Anal tranroophageal study. which included cross-,ecl~onal imagmg. color flow mapping arid pulsed wave Doppler mterrogau”n. aa\ pcrformcd. Tiansgatnc short-a*is scans and M-mode recurdings were used to assess ventricular function and detect regional wall motion abnormalities immediately akr the procedure. The probe wa\ then removed before the final catheierization and angiocardmgraphic xludy.

Results l+rb~l~nwzlion

Srudies

Tranresophageal studies carrled out before the interventi”naI procedures documcmed a previously undetected moderate secundum type atrml scptal defect in one patient Case 8) WIIJ ws schedkd for pulmonary valvuloplasty. Although the atrial septsl defect war partially covered by a redundant tissue Rap of the fossa ovalis. an unrestrictive left to right shunt was documented on both color Row mapping and pnised waw Doppler mterrogalion. Subsequentoximetnc measoremems delcrmincd aQp/Qs ratio &2.3-t. Poimonary valvuloplaaty was thus canceled and surgical correction WE planned. In (I rmwd pnrienr wirh aorric stenosis IPariennr 14J, whore precordial study had ddned mild aortic regargim riots, Ihe transesophagcal study detected moderate regurgitation. The morphologic correlde was defined as partial prolapre of the right coronary leaflet of the oortic valve. After angiocardiographic confirmation of the severity of aortx regurgitation, aortic valvuloplarty was canceled and the patient ws ssheduled for pulmonary autograft replacemenr. In all three gormrs wirk rgsremir porhwqv ohsmcrion nfrer o Mustard procedure fCam I/. I2 ortd 22~. the tranvesophageai study clearly defined the site. extent and morphology of the obstruction. These features could not hr appreciated in such derail by either the prior precordial ultrasound study or the concomitant a+jc-Trdiographic study. Angiagraphy u’as parricularly limited in defining the lengrh and minimal diameter of the obstruction. Tranresophqeai pulsed wave Doppler assessment of the Row patterns across these narrowings revealed continuous turbulent flow pattern%, which did not reach baseline values throughout the cardiac cycle. However. because of malalignment to Row across these lesions. the technique failed to predict precisely

va~v”l”plasty. Ii contrast. abnormal aortic valve murphol“gy wa documented in great detail in al! five patients scheduled foraortic vnlvuloplasty. Fusion of the aortic valve comm,swres could he nccuratcly defined and the presence and exaci “rwn of aon~c regurgitation (IWO padents) were readdy !dentified. In one patient with left pulmonary artery stenous (Case 17). the interposition of the left main bronthus belwcen the aophagus and the lesion precluded the reliable assessment of the morphology of the obstruction. The morphology of a patent ductus arteriosus could not be defined in two patients (Case$5 and 6). In two patients. both scheduled lor angioplasly for aortic recoarctation, aingleplane transesophageal studies were inadequate in defining the extent of the recoarctation and its relati”n to the left subc!avian artery. However. the presence ofintimal changes or aneurym could he excluded reliably by transeaophageal cross-sectional imaging before the procedure. Inferventionol

Studies

Pulmonary valvuhplasty. In one (Case 4) of the eight patients who underwent pulmonary valvuloplarty, moderate tncuspid regurgitation was documented immediately after successful dilation. Cross-sectional transesophageal imaging defined partial chordal rupwre of the anterior tricuspid valve leaflei with prolapse inl” the right atrium as the underlying c~“se (Fig. I). Tricuspid regurgi’atian was confimed at subsequent angiagmphy and mild regurgitation pwirt,d during the early follow-up period. Guide wire and catheter placement had not been monitored by tramesophageal imaging in this patient early in the series because we were unaware of the need to monitor positioning relative to the AV valves and their subvalvular apparatus. After this case, the study protocol WE changed accordingly. In a later patient (Case IO). the balloon was demonstrated to be localized within the tricuspid valve apparatus immediately before inflation. Subsequently. the catheter was advanced funher until its position was documented to be well beyond the tricuspid valve apparatus. Postvalvulaplasty trmnesophageal studies excluded tricuspid regurgitation in this and the remaining six patients. Any immediate change in either pulmonary valve morphology, residual w.lvular or subvalvular gradient or pulmonary incompetence could not be determined by single-plane transesophageal studies. Aortic ralwloplasty. The transesophageally determined diameter of the aortic root correlated well wirh the angiographically derived measurement in all four patients who underwent the procedure Imaximal difference in measurements * 4%). Fusion of aortic valve commissures and the immediate changes in valve morphology after dilation could

Pulmonar)

angioplasiy.

In one patient

with

lefl pulmo-

nary artery \!enosis (Care 17). the interpawn? of the left maw bronchus beween the esophagus and rhir wucture precluded adequate visualization of the stenow. However. a dlsral segment of the left pulmonary artery could be visualirrd anterior to the descending aorta and lurbulent Row was notsd. wthm

be assessed in detail. In all four patients. (here uias openmg of at least one commissure noted with marked m~provemenr of leaflet motility as awared by real mne imaging and M-node studies. Partial or complete prolapse of an aortic valve

leaflet

could

be excluded

in all pattcnl$

immedmtely

Afkr the procedure. Ihe distal left pulmonary

color Aow mapping artery demonstrated

smdies laminar

RN pa!terns and pulsed wave Doppler ?amp!ing excluded increased Row velocities. k&c angioplasty. The extent uf aoriic recoarctation lin tuo patienlsl was ditiicuh to awzss by lransverse-axis tranxwphageal imaging. Only rbe use of continuous M-mudc ~~errogation of the lumen diameter while slowly withdrawng the probe allowed a rough estimation of the extent

of Ihe

narrowed

wgment.

However.

the

minimal

after each balloon mflalion. Color Row mapping studn of the left ventricular outflow Lriicl and ilort~c v&w perfurmed after each balloon inflation d&cd trivtal aorric regurgiution

crock-~ecuonal diameter ;uwed and the intimill

in two patient% (Rg. ?) and mild lccntrall aurttc repurg&mon in a ihwd patienl. Guide wire and balloon placement had been momtored before the prwxdurc m three of Ihe% four padems. Documentation of powomng rrf the guide uirc

A locillired m~mal dissecliun or aneuryvn formation immedntcly ;xRer ;~ngmplasty WI excluded m borh patienls. Thu perpcndxular onentation of the descendmg aorla and the iranrewphagcol ultrasound bcatn precluded any meanm8ful

withm

puked

the chordal

dppaiatu

uf Ihe nliilal

i:dve

tn one of

wi!ve

Iloppler

of the conrcIa~!on was accurately iayerr could be vnualized in detad.

intcrro&n.

stenosis was enhanced bv transesoohaeeal real tnmc imaing of the catheter tip reladve to the sit; of communicat?on~ After balloon dilation of the obstruction in this patient. the maximal diameter of the narrowing was increased to IO mm. Pulsed Doppler assessment of the Row patterns across the narrow&. revealed a persistent mild increase in maximal forward I& velocity .6 m/r) and demonstrated a return to a typical biphaslc flow pattern that reached baseline values during the cardiac cycle and thus suggested successful gradient relief. In addition. any newly acquired baffle leakage was excluded by color flow mapping studies. The findings were subsequently confirmed by the final catheterization and angiographic study. P&d wave Doppler stud& Flow patterns within the pulmonary uein~ and across the AV valves were assessed in all patients before and after the interventional procedure to detect any immediate changes in these flow profiles. After pulmonary valvuloplasty, a marked increase in systolic forward Row components of the pulmonary venou return was documented in five of the eight patients (Fig. 4). whereas the flow patterns woss either AV valve remained unchanged. There was no correlation between these changes and the pre- and postdilation gradients nor with the patients’ age. No immediate changes in pulmonary venous and mitral valve Row patterns were noted after aortic valvuloplasty (Fig. 5). aortic angioplasty 2nd ductus occlusion. In the patient who underwent pulmonary angioplasty. pulmonary venous Row patterns of the left lung compared with the right lung were markedly reduced before dilation. After successful dilation. flow patterns of pulmonary venous return in both lungs became almost identical. During balloon inflation with complete occlusion of the pulmonary artcry, only to and fro Row patterns within the left pulmonary veins were demonstrated.

ti

Figure 3. Case 12. Transerophageal cross-secdond imagng of a severe ohrbuction inthe superior ofthe systemic pathway after a Mustard proccdurc and before attempted balloon dilation. The obrtmctwc lesion (9 is heavdy calcited. leaving only a pinhole openingol l-mm diameter t>). WA = Qulmonary venous atrium: SI;P SVA = sugeriorlimb systemicvenousatrium; SVC = superior vcna cwa: other abbreviation ar in Figure 2.

limb

Dueta welusion. Tramesophageal studies during tranrcathctcr occlusion of a patent ductus artcnosus in two patients failed to provide useful information on the exact position of the occluder device. However, protrusion of the distal legs into the lumen of the descending aorta could be excluded cm cross-sectional imaging and color Row mapping of the descending aorla allowed us to exclude turbulent Row Qattcrns. Pulsed wave Dopcder and color Row mapping &dies of the flow pane& within the pulmonary trunk defined a minuscule residual shunt immediately after the procedure. The finding was confirmed in both patients by a final aortogram. In one patient ICase 61. residual shunting ceased after IO min. Mustard baAlo dilation. In one (Case I I) of the three patients studied. the tranreaophagcal cross-sectional imdging and color Row mapping study defined complete occlusion of the superior limb of the nystemie venous pahwsy. No anterograde Row was recorded by pulsed wave Doppler interrogationjust distal to the occlusion. Numerous attempts to cross this lesion from the femoral vein with a guide wire wcrc unsuccessful. In the second patient (Case 12). a pinhole oQeniw in a heavily calcified obstruction at the level of the rimnait of the at& septum was documented (Fig. 3). Despite rransesophageal demonstration of the entire s!!perim limb of the systemic venous atrium and real time monitoring of catheter manipulations, the transfemorai advancement of the guide wire remained unsucccr~lul In the third patient (Case 22). the lesion was documented to be a low concentric narrowing with a cood.sized wenine. (4 mm). On color Row mapping and pulsed wave Doppler studies, continuous turbulent Row was recorded across this obstruction. Guide wire and catheter placement across the

Discussion Transeraphageal echocardiography using dedicated pediatric probes is a safe diagnostic and monitoring technique in children weighing 13 kg 115-17). To date. 26% studies have been carried out at our instilutionr and complications were encountered in only 4 (arrhythmias in 2. bleeding in and pulmonary hypertensive crisis in 1). No death occuned. General anesthesia together with endotracheal intubation is considered to be the optimal anesthetic technique for such studies. although theseCan be performed under heavy sedation. In Ihe reported subset of patients undergoing interven. tional cardiac catheterization, no complications were encounrered. The interventional procedure time wits not pmlongcd and sterility was not endangered by these studies. Early during the series, the presence of the tran%erophageal pmhe was believed to interfere with the routine radiographic monitoring and frequently had to be removed to a high esophageal position. However. with growing opermor familiarity with the standard transesophageal imaging

I

Figm

4. c&e

7. Transesophageal

oulred wave Doookr intenoeetion of

imp!nnd.after ,betteml &,onary

balloon valvulo~larty. Beforethe procedure (pre). the systolic foward Row companent is decreased. After successfulgradient relief (p&l. the systolicRow component increesedmarkedly, wnereas the diastolic Row com,,onent remained rela. tively unchanged. L”P” = left upper ~“lmonaty ,” in: RW” = right upper pulmonary vein.

planes, the real time imaging information provtded by the technique often was used specifically to monitor guide wire cad balloon catheter placement. Thus, later in the serier. studies no longer were believed to interfere with the procedure, but were considered to constitute an important addition to routine monitoring. Preintewentlm studies, These provided a detailed assessment of cardiac morphology and fwctian immediately before the procedure. In this series. the inform%ion obtained led to cancellation of the procedure in two patients. In another patient. who had systemic venous pathway obstruction after a Mustard procedure. the finding of complete exlusion of the superior limb of the baffle could have led to early cancellation. In the remaining two patients with baffle obstruction. the transesophageal imaging studies prowded additional morphologic insights into the ubztructive lesions and were believed to enhance greatly the catheter placement. Monitoring of guide wire and catheter positioning during balloon valvuloptarty and duetus wcluaion. This wes found to be one of the major cantributmns of the technique. Although in pulmonar; and sonic val~~loplasty the balloon catheter is inflated only after adequate positionmg is assessed by Ruoroscofy. the ri>k of entrapment within the valvular or subvalvular apparatus of the AV valves cannot

be excluded completely. This is especially important in neonater and infants because of relatively longer balloon length versus chamber dimensions. In the one patient in whom tricuspid regurgitation was identified after pulmonaty stiffbackur, wide wire was used for balloon valv~lo~la~t~, cathete; pla&ment. Tricus$d valve chordae tendineae were prerumably parttally sheared off. After this instance. tmnsesophageal studies were specifically used to monitor gutde wire a~ well as b&on position across the AV valves in all patiects. Visualization could be achieved in great detail in all and the finding3 initiated carheter repositioning guided by trao .esophageal imeging in two patients. Evaluation of immediate morpbologie changes. After the interventional procedures in our series of patients. the tranresophageal studies were of benefit in assessing aottic wlve morphology (commissures and cuspsL descending aortic wall moroholocv Ilumen diameter and intimal integrity) and systemic pathway obstruction after the Mustard prucedurc werall dimensions). However. no useful information on either pulmonary valve morphology or umbrella position. within an an&l ductus was obtained by single. plane transeaophageal imaging. The failure to adequately visualize the arterial ductus can be explained by interpasit,on of the bronchial tree between this structure and the esophagus. After unauccesaful studier in two patients under-

a

Figure5. Cast 9. Transesophageal pulsedwaveDopplerintcrrogatmn of pulmonary YCDOYS Row profiles before tt~d and after Ibottom aortic balloon valvuloplarty.The pulmonaryvenom Row patternswithin the tett upper pulmonary vein (LUPV) remained essentn.ltyunchangeddespitesuccessfulgradientr&t. Abbrwiationr asin Figure4.

going transfernor. ductus occlusion, no more patients underwent the study. Transgastric short-axis imaging and M-mode studies allowed for the monitoring of left ventricular function during the procedure and recovery period. In addition they made it possible to exclude left ventricular regional wall motion abnormalities, a capability that was especially important after aonic valvuloplasty. Assessmentof hemcedynamicchanges immrdletely after interventional procedures. Such assessmentwas found to be limited. Color flow mawine. studies toEether with color M-mode recordings pro;;ded a rough indicator of residual obstructions, patticularly after aortic valvuloplasty. Hcwever, residual gradients acrosseither arterial v&e could not be assessedbecause of the generally poor alignment of the Doppler beam with these flow patterns and the availability of pulsed wave Doppler facilities only. Similar limit&xv were encountered in the aswsment of descending aartic flow patbms. In ~(lntrast, the asse~~metttof Row p&ems within the systemic venous pathways in patients with a Mustard procedure contributed unique additional information. After

successful dilation. the continuous turbulent Row pattern acrossthe obstruction becamebiphasic and reached baselme values during the cardiac cycle. Exclusion of immediate complications. This was found to be an important advantage of transesophageal monitoring during interventional catheterization. The technique provided-continuous morphologic and bemodynamic information without interfering with the procedure. The immediate exclusion of aortic regurgitation after each balloon Inflation for dilation of the aortic valve proved to he of major value in this series of patients. Second or third balloon inflations were performed with much greater confidence than when they had been performed without real time tmnsesophageal monitoring. After Mustard be& dilations, the technique allowed for the immediate exclusion of bat% disruption or leakage. The sensitivity of transesophagealcolor Row mapping &dies in the d&ion of these k&s is such that the technique may eventually obviate final at&graphic studies. In ad&lion, the majority of other potential compbcations that may occur during the various procedures should be immediatelv and reliablv identifiable by continuous transesophageal monitoring. Pulsed wave Doppler studi= of AV and pulmonary venous Row patterns. Thdie revealed several i&resting insights into the immediate changes after various interventional procedures. After aortic valvuloplasty. no immediate changes in these Row patterns were obwved. These observations are in aweement with the tindine bv Stoddard et al. (26). who excl&d an immediate change in left ventricular function on tbc basisof unchanged mitral valve Row pat&ems after aortic valvuloplasIy. Similar observations cm pulmonary vein and AV valve Row patterns were made in the two patients who underwent successful angioplasty for recoatv tation and in two patients after ductus occlusion. In cotUrast. in five of the eight patients who underwent successful pulmonary valvuloplasty, marked changes in pulmonary venous flow patterns were noted imrcediately after the procedure. In all five patients. the systolic component of pulmonary venous forward flow was found to be largely increased after gradient relief. Systolic forward flow is caused by both atrial relaxation and descent of the mitral valve a~~lus during vcnltictdar systole (27). Improved atria1relaxation is unlikely to be the underlying cause of these observations, thus suggesting an immediate change in left ventricular systolic geometry and function after mdmonar~ valvulo~last~. There was no sig_ nificant differ&e in the-changes in cardiac output between the subset of patients who had a change in pulmonary venous Row patterns and those who did not. The diastolic flow component of pulmonary venous return and the AV valve Row patterns remained unchanged. suggesting that there are no immediate changes in diastobc right and left xntricular function after successful pulmonary valvuloplasty. Unchanged diastolic right vertthcular f&ion after pulmonary valvuloplasty was recently reportid ty Vermilion et al. (28). More detailed studies to further elucidate

these phenomena are currently under way During pulmonary angioplasty. Ihe comparison of pulmonary venous Row oatlerns in either lone mav be uvful m assessme rbe

These include the poor demonstrarion ofrhenghr ~entncul~r outflow tract. the pulmonary valve. the precxe morphology of a&c coarctation and the anatomy of a pawn duc~us arteriasus. It may be anticipated lhat severA of these hrrw tations may be overcome by the Lime biplanc.fransesophageal imaging (29) becomer available for study in chddrcn. The additional longitudinal-axis images ihnr are ablamed allow for an improved assessmenfof thesecardiac struc~res and facilitate Doppler mrerrogauon (30). In addillon. the adjuncl of continuous wave Doppler facdmer may provide much improved inrighl into the munedidre hemodynamic changes such an residual valvnlar gradients. Further applications. Tranrescphagerl real t~mc monimring of interventional cardiac catheterizarion should have a major impact on several other procedures. Moniwnng of balloon septostoroy appears lo be parlicularly rewrding m patients with juxtaposition of the anial appendages Similarly. blade seplostomy procedures are helwed IO be greatly enhanced by such monitoring. The monitoring of balloon dilation of pulmonary venous obstructloos would allow continuous assessment of morphologic and hemodynamic alterations. In addition, the moniroring of cod embolizarions of coronary artery fistulas may be beneficial. The impact of transesophagealmonitoring of lranscatheter closure of atrial septal defects was recenlly described by Hellenbrandt el al. 131)and if appears that the technique may become a prerequisite for a high wccess mw. The monironng of vemricular septal defect closure is currently under evalllation BI several institutions. Conclusiono, Tramesophageal echocardiographic mow toring of interventional cardiac cathererizerion in children is a safe technique the1 does not imerfere wrh Ihe pmcedure. It pmvides additional important morphologic mformadon oo a wide speclrum of lesion,. lhe immedmte ldenrlficatmn or exclusion of potendal complicalions and rhc a~icssmem of hemodynamic changes. It may be expected whatin the new future. the technique may become an inleqral part of pedlatric cardiac inkrventions.