Aneurysmal aorto-left ventricular tunnel causing right ventricular outflow tract obstruction, associated with bicuspid aortic valve

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  • CASE REPORT

    Aneurysmal aorto-left ventricular tunnel causing right ventricularoutflow tract obstruction, associated with bicuspid aortic valve

    Rodica Toganel Theodora Benedek

    Carmen Suteu Imre Benedek

    Received: 28 August 2013 / Accepted: 8 November 2013

    Springer Japan 2013

    Abstract We report the case of a newborn with an

    aneurysmal aorto-left ventricular tunnel causing significant

    paravalvular aortic regurgitation and obstruction of the

    right ventricular outflow tract (RVOT), coexisting with a

    bicuspid aortic valve. The coexistence of the two malfor-

    mations together with the obstruction of the RVOT is very

    rare. In this case, the prompt diagnosis and surgery led to

    significant improvement of the clinical status and to

    recovery of the left ventricular function (increase of the

    ejection fraction from 21 to 41 %), underlining the

    importance of early diagnosis in this rare malformation.

    Keywords Aorto-ventricular tunnel Congenitalheart disease Aortic regurgitation

    Introduction

    Congenital aorto-left ventricular tunnel is a rare heart

    disease, accounting for up to 0.10.5 % of congenital heart

    malformations, with a higher frequency in male patients

    [1]. This anomaly was first described by Levy et al. in 1963

    [2], after which very few cases have been reported.

    Aorto-left ventricular tunnel consists of an extracardiac

    direct communication between the aorta and the left ven-

    tricle. In most of these cases, the communication originates

    from the aorta above the sinotubular junction and

    terminates in the left ventricle, below the right coronary

    cusp [3]. The etiology of this malformation remains

    uncertain; however, several authors have suggested that it

    is linked to the maldevelopment of the cushions, giving rise

    to the pulmonary and aortic roots, associated with an

    abnormal separation of these structures [4]. In nearly half

    of these cases, associated defects of the aortic and pul-

    monary valves or of the proximal coronary arteries are

    recorded [5, 6].

    Case report

    We present the case of a newborn (male, gestational age 37

    weeks, birth weight 3,550 g), referred to our institution at

    21 days after his birth for a continuous systolicdiastolic

    left parasternal murmur and symptoms of heart failure:

    severe dyspnea, diaphoresis, and unsatisfactory growth

    rate. Chest X-ray revealed significant cardiomegaly, with a

    cardiothoracic index of 0.75 and a broad upper mediastinal

    shadow from the enlarged ascending aorta. The electro-

    cardiogram showed signs of left ventricular hypertrophy.

    Echocardiography showed a dilated left ventricle with a

    very low ejection fraction (EF) of 21 %, and a significant

    bidirectional turbulent flow via a tubular communication

    between the aorta and the left ventricle, located anterior to

    the aortic root and bypassing the aortic valve (Fig. 1). The

    orientation of the flow was from the left ventricle to the

    aorta in systole and from the aorta to the left ventricle,

    resulting in a significant paravalvular aortic regurgitation,

    in diastole. Echocardiography identified both ends of the

    communication, the aortic one above the coronary sinus

    and the left ventricular one below the right coronary cusp.

    According to this echocardiographic aspect, the commu-

    nication was diagnosed as an aorto-left ventricular tunnel,

    R. Toganel T. Benedek C. Suteu I. BenedekUniversity of Medicine and Pharmacy Tirgu Mures, Tirgu

    Mures, Romania

    T. Benedek (&) I. BenedekCardiomed Medical Center Tirgu Mures, 22 decembrie 1989 no.

    7678, Tirgu Mures, Romania

    e-mail: hintea_teodora@yahoo.com

    123

    Heart Vessels

    DOI 10.1007/s00380-013-0445-8

  • which appeared to be aneurysmal, with a diameter of 6 mm

    at the aortic end and 8 mm at the ventricular end.

    Echocardiography also revealed a bicuspid aortic valve

    with minor valvular regurgitation, and a significant dila-

    tation of the ascending aorta (aorta diameter 18.6 mm, with

    Z-scores of 5.86 at the level of the aortic valve and 7.07 at

    the level of the ascending aorta). Because of its aneurysmal

    nature, the tunnel compressed the right ventricular outflow

    tract (RVOT), causing obstruction at this level (peak sys-

    tolic gradient 20 mm Hg) (Fig. 2).

    Surgical intervention was decided upon, and the patient

    was operated on at week 5. The repair was achieved by the

    obliteration of the tunnel under extracorporeal circulation.

    Postoperatively the status of the patient significantly

    improved, and he was discharged on day 16 after surgery.

    Echocardiography at discharge revealed a recovered left

    ventricular function (volumetric EF of 41 %), minor aortic

    regurgitation, and no obstruction at the RVOT.

    Discussion

    An aorto-left ventricular tunnel is one of the most impor-

    tant causes of severe heart failure in newborns, caused by

    the associated significant regurgitation via the tunnel from

    the aorta to the left ventricle [7]. Even though the diagnosis

    of this anomaly could be easily established in the prenatal

    period, it is usually diagnosed only after birth, when

    symptoms and signs of left ventricular volume overload

    become evident.

    Very few reports of aortoventricular tunnels are pre-

    sented in the literature, most of them describing the asso-

    ciation of the tunnel with other coexisting abnormalities of

    the aortic valves or coronary arteries [8]. However, to the

    best of our knowledge there is no case published so far

    describing the coexistence of an aneurysmal tunnel with an

    RVOT obstruction and bicuspid aortic valve at the same

    time. It has been suggested in the literature that an aneu-

    rysmal aorto-left ventricular tunnel could cause RVOT

    obstruction owing to the presence of the right ventricular

    infundibulum in the proximity of the aortic sinus, where

    the tunnel terminates [9]. In this case, a left ventricular hole

    of the defect larger than the aortic one caused the aneu-

    rysmal dilation of the tunnel. As the tunnel was located in

    immediate proximity to the RVOT, anterior to the aortic

    root, the aneurysmal dilation of the tunnel caused bulging

    of the septum into the right ventricle, which could explain

    the reversible mild RVOT obstruction.

    The coexisting anomaly of the aortic valve most likely

    has a common etiology with the tunnel, with both being

    Fig. 1 Echocardiographicexamination, modified

    parasternal long-axis view.

    Right B-mode examination:junction of tunnel (T) to Aorta

    (Ao) above the coronary sinus,

    measured as 6 mm in diameter,

    and to the left ventricle (LV),

    measured as 8 mm in diameter.

    MV mitral valve, LA left atrium,

    AoV aortic valve. Left ColorDoppler examination: flow

    through the tunnel in diastole,

    creating a significant aortic

    paravalvular regurgitation. The

    communication is visible in its

    entire length (arrow)

    Fig. 2 Echocardiographic examination, aortic short-axis view. Visu-alization of turbulent flow in the RVOT (arrow), compressed by the

    aneurysmal tunnel. PA pulmonary artery, RVOT right ventricular

    outflow tract

    Heart Vessels

    123

  • caused by a maldevelopment of the cushions, giving rise to

    the aortic root in the embryonic period.

    The coexistence of the two malformations together with

    the obstruction of the RVOT creates a very rare and

    interesting clinical picture in this case. However, as the

    valvular regurgitation associated with the bicuspid aortic

    valve was only mild, it did not require repair. Therefore the

    surgery consisted only of the repair of the tunnel, which led

    to the disappearance of the paravalvular aortic regurgita-

    tion, recovery of the left ventricular function, and regres-

    sion of the RVOT obstruction.

    The differential diagnosis of an aorto-left ventricular

    tunnel includes ventricular septal defect, rupture of the

    sinus of Valsalva, and coronary arteryleft ventricular fis-

    tula [10, 11]. The echocardiographic appearance of the

    tunnel shows many similarities with a subaortic ventricular

    septal defect, given the opening of the ventricular end of

    the tunnel in the subaortic region [12, 13]. In our case, the

    ventricular septal defect was excluded by the absence of

    any shunt or right ventricular overload. A ruptured sinus of

    Valsalva was excluded by the absence of a dilated sinus of

    Valsalva, and the coronary arteryventricular fistula was

    excluded by the normal appearance of the coronary arter-

    ies. Interestingly, in this case the severe aortic paravalvular

    regurgitation within the tunnel was associated with a mild

    aortic valvular regurgitation caused by the bicuspid aortic

    valve. The coexistence of valvular and paravalvular aortic

    regurgitation can frequently lead to diagnostic errors,

    confounding the rare malformation (the tunnel) with the

    more frequent one (valvular regurgitation caused by the

    bicuspid aortic valve), especially when the regurgitant flow

    is eccentric and is visualized in apical views. The false

    attribution of the regurgitant flow within the tunnel to the

    regurgitation across the bicuspid valve leads not only to the

    missed diagnosis of the tunnel but also to overestimation of

    the severity of aortic valve disease.

    The optimal management of patients with an aortoven-

    tricular tunnel consists of early diagnosis followed by a

    prompt surgical repair. In the presence of a symptomatic

    newborn with left ventricular failure, echocardiographic

    examination should be performed as soon as possible [14].

    However, owing to the very rare nature of this malforma-

    tion, the tunnel remains unrecognized in many cases. Given

    the importance of immediate surgery for preventing evo-

    lution toward severe left ventricular failure, the examiners

    should search for this pathologic appearance in any fetus or

    newborn with signs of aortic regurgitation. Furthermore,

    prenatal diagnosis could indicate the referral for delivery in

    a tertiary care center where all the necessary facilities for

    appropriate assistance, including cardiac surgery for an

    immediate postnatal surgical repair, are available.

    References

    1. McKay R, Anderson RH, Cook AH (2002) The aorto-ventricular

    tunnels. Cardiol Young 12:563580

    2. Levy MJ, Lillehei CW, Anderson RC, Amplatz K, Edwards JE

    (1963) Aortico-left ventricular tunnel. Circulation 27:841853

    3. Horvath P, Balaji S, Skovranek S, Hucin B, de Leval MR, Stark J

    (1991) Surgical treatment of aortico-left ventricular tunnel. Eur J

    Cardiothorac Surg 5:113117

    4. Mitropoulos FA, Laks H, Kanakis MA, Levi D (2006) Aorto-left

    ventricular tunnel: an alternative surgical approach. Ann Thorac

    Surg 82:11131115

    5. Mori Y, Takahashi K, Nakanishi T (2013) Complications of

    cardiac catheterization in adults and children with congenital

    heart disease in the current era. Heart Vessels 28:352359

    6. Le Gloan L, Mongeon FP, Mercier LA, Dore A, Marcotte F,

    Ibrahim R, Asgar A, Miro J, Poirier N, Khairy P (2013) Tetralogy

    of Fallot and aortic root disease. Expert Rev Cardiovasc Ther

    11:233238

    7. Nezafati MH, Maleki MH, Javan H, Zirak N (2010) Repair of

    aorto-left ventricular tunnel arising from the left sinus of Val-

    salva. J Card Surg 25:345346

    8. Singh SK, Dwivedi SK, Kumar A, Vijay SK, Rajput N, Devenraj

    V, Lal Sahni J (2012) Aneurysmal aorto-right ventricular tunnel.

    Ann Thorac Surg 93:e21e22

    9. Troubil M, Lonsky V, Petr S (2010) Aorto-left ventricular tunnel

    causing severe aortic regurgitation in adult man. Eur Heart J

    31:145

    10. Yoshino S, Minagoe S, Yu B, Kosedo I, Yamashita M, Ishizawa

    M, Kono M, Setoguchi M, Nakashima H, Matsuoka T, Suehiro S,

    Yotsumoto G, Yamashita M, Tei C (2013) Cardiac tamponade

    due to rupture of coronary artery fistula to the coronary sinus with

    giant aneurysm of coronary artery: usefulness of transthoracic

    echocardiography. Heart Vessels 28:536540

    11. Zanjani KS, Niwa K (2013) Aortic dilatation and aortopathy in

    congenital heart diseases. J Cardiol 61:1621

    12. Knott-Craig CJ, van der Merwe PL, Kalis NN, Hunter J (1992)

    Repair of aortico-left ventricular tunnel associated with subpul-

    monary obstruction. Ann Thorac Surg 5254:557559

    13. Wei Y, Wang X, Zhang S, Hou L, Wang Y, Xu Y, Sun Q, Zhao H

    (2012) Transcatheter closure of perimembranous ventricular

    septal defects (VSD) with VSD occluder: early and mid-term

    results. Heart Vessels 27:398404

    14. McKay R (2007) Aorto-ventricular tunnel. Orphanet J Rare Dis

    2:41

    Heart Vessels

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    Aneurysmal aorto-left ventricular tunnel causing right ventricular outflow tract obstruction, associated with bicuspid aortic valveAbstractIntroductionCase reportDiscussionReferences

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