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Aortico-Left Ventricular Tunnel: Diagnosis Based on Two-Dimensional Echocardiography, Color Flow Doppler Imaging, and Magnetic Resonance Imaging

1986; Elsevier BV; Volume: 61; Issue: 11 Linguagem: Inglês

10.1016/s0025-6196(12)62613-5

1942-5546

Richard A. Humes, Donald J. Hagler, Paul R. Julsrud, Jay M. Levy, Robert Feldt, Hartzell V. Schaff,

Infective Endocarditis Diagnosis and Management

Aortico-left ventricular tunnel is a rare congenital cardiac lesion that often results in severe aortic insufficiency in infancy. In previously reported cases, the diagnosis has often been missed initially despite use of cardiac catheterization and angiography. We describe a patient who underwent successful surgical correction of this malformation at 10 months of age after the diagnosis had been established by use of two-dimensional echocardiography, color flow Doppler imaging, and magnetic resonance imaging. Aortico-left ventricular tunnel can be diagnosed by use of these noninvasive means without cardiac catheterization. Aortico-left ventricular tunnel is a rare congenital cardiac lesion that often results in severe aortic insufficiency in infancy. In previously reported cases, the diagnosis has often been missed initially despite use of cardiac catheterization and angiography. We describe a patient who underwent successful surgical correction of this malformation at 10 months of age after the diagnosis had been established by use of two-dimensional echocardiography, color flow Doppler imaging, and magnetic resonance imaging. Aortico-left ventricular tunnel can be diagnosed by use of these noninvasive means without cardiac catheterization. Aortico-left ventricular tunnel is a rare congenital heart defect that often results in severe aortic insufficiency in infancy. The anomaly is a communicating channel between the ascending aorta and the left ventricle; it was first described in 1961, by Edwards1Edwards JE An Atlas of Acquired Diseases of the Heart and Great Vessels. Vol 3. W. B. Saunders Company, Philadelphia1961: 1142Google Scholar who considered it an acquired lesion. In 1963, Levy and associates2Levy MJ Lillehei CW Anderson RC Amplatz K Edwards JE Aortico-left ventricular tunnel.Circulation. 1963; 27: 841-853Crossref Google Scholar recognized the congenital origin of the defect. Forty-seven cases of this rare lesion have been reported in the literature, and many were initially misdiagnosed when standard invasive (catheterization) and noninvasive techniques were used. In this article, we describe our experience with diagnosis of this malformation by using the noninvasive techniques of two-dimensional echocardiography, color flow Doppler imaging, and magnetic resonance imaging. The patient was a 940-g premature male infant, born at 28 weeks of gestation to a 27-year-old mother. The pregnancy was complicated by intermittent vaginal bleeding for 4 months before delivery and a difficult vaginal delivery with abruptio placentae. He required mechanical ventilation for 2 days and had a neonatal course that was complicated by apnea and episodes of bradycardia, jaundice, retrolental fibroplasia, and bilateral inguinal hernias. A cardiac murmur was heard at 1 day of age, and the initial echocardiogram was thought to be consistent with a ventricular septal defect. He was dismissed at 2 months of age. The patient did well until 8 months of age, when he was hospitalized for bronchiolitis and pneumonia. He had no history of cyanosis or diaphoresis although poor feeding and dyspnea had been noted. At this time, congestive heart failure was diagnosed and therapy with digoxin was begun. Cardiac catheterization was done when the patient was 9 months old. A hemodynamic summary is shown in Table 1. Aortic root and left ventricular angiograms were thought to disclose an aneurysm of the sinus of Valsalva and severe aortic insufficiency (Fig. 1). At 10 months of age, he was rehospitalized because of tachypnea and wheezing thought to be consistent with bronchiolitis. Furosemide was added to the medical regimen. He was referred to our institution for possible surgical correction.Table 1Summary of Hemodynamic Data*Cardiac index = 2.4 L/min/m2. in 9-Month-Old Infant With Aortico-Left Ventricular TunnelSite of measurementPressure (mm Hg)Oxygen saturation (%)Ascending aorta110/44…Left ventricle110/16…Left atrium20/1197Main pulmonary artery24/1461Right ventricle32/761Right atrium9/460Superior vena cava…60* Cardiac index = 2.4 L/min/m2. Open table in a new tab Physical examination at the time of referral revealed a child who was below the fifth percentile for height and weight. The blood pressure was 100/60 mm Hg, and the pulses were bounding. The apical impulse was normally positioned in the fifth intercostal space. The first heart sound was normal, and the second heart sound was obscured. A systolic murmur and a diastolic murmur were detected, both grade 3 (on the basis of 1 to 6), audible along the left sternal border and apex, and having a to-and-fro quality. The liver was enlarged 5 cm below the right costal margin. Chest roentgenograms demonstrated cardiomegaly (cardiothoracic ratio, 68%) but normal pulmonary vascularity. The electrocardiogram and vectorcardiogram demonstrated left axis deviation and left ventricular hypertrophy. Two-dimensional echocardiography and color flow Doppler imaging were performed with the patient mildly sedated; an Advanced Technology Laboratories MK600 instrument (with a 5-MHz scanning head) and an Aloka 880 instrument (with 3.5- and 5-MHz scanning heads) were used (Fig. 2, Fig. 3). These studies revealed moderate concentric left ventricular thickening and enlargement but normal contractility. The trileaflet aortic valve had mildly thickened valve cusps that domed during systole and prolapsed somewhat during diastole. A continuous-wave Doppler examination of the left ventricular outflow tract demonstrated a 3.0 m/s systolic velocity, consistent with a 36 mm Hg maximal instantaneous gradient. In addition, a 4.4 m/s early diastolic jet was present, consistent with aortic regurgitation. A tunnel originated in the outlet septum beneath the right coronary cusp and terminated in the ascending aorta superior to the right coronary aortic sinus, its course lateral and slightly superior to the right coronary artery. Color flow imaging demonstrated unobstructed to-and-fro (systolic and diastolic) flow in the tunnel with a high-velocity color signal that aliased during systole. Severe aortic regurgitation through the tunnel was demonstrated with parasternal and apical scans. Preoperative color flow imaging demonstrated no evidence of turbulent systolic flow or obvious diastolic flow across the aortic valve. The “double-outlet” nature of this anomaly did not allow accurate assessment of native aortic valve stenosis by either invasive or noninvasive (continuous-wave or color flow Doppler) techniques. No evidence was found of ventricular septal defect or other valvular abnormality.Fig. 3Color flow Doppler imaging from parasternal long axis. A, Image during early diastole shows inflow (orange) through mitral valve (large arrowhead). Regurgitation into left ventricle through tunnel (arrow) is depicted as speckled yellow and blue, indicating turbulent high-velocity flow. B, Corresponding two-dimensional still frame depicts tunnel (arrow). C, View during late diastole shows continued regurgitation through tunnel (arrow) into left ventricle. D and E, Systolic and diastolic frames show orange forward flow (large arrowhead) through tunnel during systole (SYS) and speckled, turbulent, regurgitant flow (arrow) during diastole (DIAS). For explanation of abbreviations, see legend for Figure 2.View Large Image Figure ViewerDownload (PPT) Cardiac gated magnetic resonance imaging with a 0.15-tesla resistive magnet for proton imaging at 6.4 MHz was used to evaluate this patient's problem further and to assess the ability of magnetic resonance imaging to demonstrate the suspected anatomic abnormality. Magnetic resonance imaging was performed after informed consent had been obtained under an institutionally approved protocol. The patient was sedated with orally administered chloral hydrate. Spin-echo pulse sequences with an echo delay time of 40 ms, a repetition time of 960 ms (gated to every second cardiac cycle), and two excitations per phase encoding view were used. The total scanning time was 55 minutes. Coronal, sagittal, and transverse image planes disclosed the aortico-left ventricular tunnel, which extended from the anterosuperior aspect of the left ventricle, anteriorly through the infundibular septum, exiting adjacent to the right coronary cusp, and coursing just above the right coronary artery to enter a dilated aortic root (Fig 4). The aortic end of this tunnel appeared considerably dilated and formed an aneurysm-like pouch anterior to the dilated aortic root. At operation, the left ventricle was moderately enlarged and the heart was generally overactive. The three cusps of the aortic valve were slightly thickened. The aortico-left ventricular tunnel was evident just to the left of and slightly superior to the ostium of the right coronary artery (Fig. 5). The tunnel orifice was 9 mm at the aortic end. The tunnel was obliterated with interrupted 5–0 Prolene sutures, and the orifice was closed with a small Gore-Tex patch that was attached with interrupted and continuous 5–0 Prolene suture. Finally, the outpouching on the external side of the aorta was obliterated with mattress sutures of 5–0 Prolene and felt pledgets. Rewarming and discontinuation of cardiopulmonary bypass proceeded uneventfully, and the hemodynamics after bypass were excellent. The patient had a smooth postoperative course and was dismissed after 7 days. Postoperative two-dimensional echocardiography and Doppler and color flow imaging demonstrated the previously noted mild thickening of the aortic valve leaflets and a continuous-wave Doppler velocity of 2.8 m/s (31 mm Hg maximal instantaneous systolic gradient). Color flow imaging demonstrated a small central diastolic jet, consistent with mild aortic valve insufficiency. No evidence of flow was detected in the remaining portion of the tunnel by color flow or pulsed-wave Doppler examination. Despite the Doppler finding of aortic insufficiency, no diastolic murmur could be appreciated postoperatively. Aortico-left ventricular tunnel is a rare congenital anomaly in which an aberrant communication is formed between the aortic root and the left ventricle. Although the exact incidence of this defect is unknown, it was found in 0.1% of congenital cardiac lesions in one published series.3Okoroma EO Perry LW Scott III, LP McClenathan JE Aortico-left ventricular tunnel: clinical profile, diagnostic features, and surgical considerations.J Thorac Cardiovasc Surg. 1976; 71: 238-244PubMed Google Scholar In a search of the literature, we found 47 previously reported cases.4Levy MJ Schachner A Blieden LC Aortico-left ventricular tunnel: collective review.J Thorac Cardiovasc Surg. 1982; 84: 102-109PubMed Google Scholar, 5Turley K Silverman NH Teitel D Mavroudis C Snider R Rudolph A Repair of aortico-left ventricular tunnel in the neonate: surgical, anatomic and echocardiographic considerations.Circulation. 1982; 65: 1015-1020Crossref PubMed Scopus (39) Google Scholar, 6Lang D Hofstetter R Kupferschmid C Quintenz R Messmer BJ von Bernuth G Aortico-left ventricular tunnel: report of three cases and review of the literature.Z Kardiol. 1982; 71: 695-704PubMed Google Scholar, 7Serino W Andrade JL Ross D de Leval M Somerville J Aorto-left ventricular communication after closure: late postoperative problems.Br Heart J. 1983; 49: 501-506Crossref PubMed Scopus (61) Google Scholar, 8Cooley RN Harris LC Rodin AE Abnormal communication between the aorta and left ventricle: aortico-left ventricular tunnel.Circulation. 1965; 31: 564-571Crossref PubMed Scopus (32) Google Scholar, 9Perry JC Nanda NC Hicks DG Harris JP Two-dimensional echocardiographic identification of aortico-left ventricular tunnel.Am J Cardiol. 1983; 52: 913-914Abstract Full Text PDF PubMed Scopus (11) Google Scholar, 10Fripp RR Werner JC Whitman V Nordenberg A Waldenhausen JA Pulsed Doppler and two-dimensional echocardiographic findings in aortico-left ventricular tunnel.J Am Coll Cardiol. 1984; 4: 1012-1014Abstract Full Text PDF PubMed Scopus (29) Google Scholar, 11Bash SE Huhta JC Nihill MR Vargo TA Hallman GL Aortico-left ventricular tunnel with ventricular septal defect: two-dimensional/Doppler echocardiographic diagnosis.J Am Coll Cardiol. 1985; 5: 757-760Abstract Full Text PDF PubMed Scopus (22) Google Scholar, 12Grant P Abrams LD De Giovanni JV Shah KJ Silove ED Aortico-left ventricular tunnel arising from the left aortic sinus.Am J Cardiol. 1985; 55: 1657-1658Abstract Full Text PDF PubMed Scopus (16) Google Scholar, 13Mair DD Fulton RE McGoon DC Successful surgical repair of aortico-left ventricular tunnel in an infant.Mayo Clin Proc. 1975; 50: 691-696PubMed Google Scholar The incidence is clearly higher among male (72%) than among female infants. The anatomy has been strikingly similar in these reported cases. The upper part of the right aortic sinus is usually dilated and projecting anteriorly. From this projection, a tunnel arises anteriorly and superiorly over the right coronary artery to terminate in the infundibular or paramembranous portion of the interventricular septum, just inferior to the right and noncoronary cusp of the aortic valve. The coronary artery is usually not involved, although one report described origin of the right coronary artery from the tunnel.5Turley K Silverman NH Teitel D Mavroudis C Snider R Rudolph A Repair of aortico-left ventricular tunnel in the neonate: surgical, anatomic and echocardiographic considerations.Circulation. 1982; 65: 1015-1020Crossref PubMed Scopus (39) Google Scholar Occasionally, aortico-left ventricular tunnel may coexist with other cardiac anomalies, such as bicuspid aortic valve, aortic stenosis, patent ductus arteriosus, pulmonic stenosis, aneurysm of the sinus of Valsalva, or ventricular septal defect.4Levy MJ Schachner A Blieden LC Aortico-left ventricular tunnel: collective review.J Thorac Cardiovasc Surg. 1982; 84: 102-109PubMed Google Scholar The cause of this condition is controversial; however, in utero aneurysmal rupture, ectopic coronary artery dissection, associated Marfan's syndrome, and abortive valvular development have been proposed as etiologic factors. The clinical, electrocardiographic, and radiographic features of aortico-left ventricular tunnel are related to the size of the tunnel. Most of these defects are relatively large (5 to 10 mm in diameter) and allow nearly free aortic regurgitation. Most cases are detected during infancy; affected patients have a loud to-and-fro murmur, a bounding pulse, and signs of congestive heart failure. Electrocardiograms usually reveal left ventricular hypertrophy and occasionally show left axis deviation; cardiomegaly and aortic root dilatation are usually evident on a chest roentgenogram. The differential diagnosis of aortic insufficiency in the neonate and infant should include ruptured aneurysm of the sinus of Valsalva, ventricular septal defect with aortic insufficiency, or isolated congenital aortic insufficiency—all extremely rare lesions. Other causes of a to-and-fro murmur such as coronary artery fistula, tetralogy of Fallot with absent pulmonary valve, or patent ductus arteriosus may be considered. Surgical closure of an aortico-left ventricular tunnel is generally thought to be the treatment of choice. In one series, all 12 patients treated nonoperatively died, compared with 5 deaths among 26 patients in the surgically treated group. Some of the deaths in the surgical group were related to coexisting lesions.4Levy MJ Schachner A Blieden LC Aortico-left ventricular tunnel: collective review.J Thorac Cardiovasc Surg. 1982; 84: 102-109PubMed Google Scholar Surgical intervention has been successful in infants since 1975 and in neonates since 1982. Methods used have included direct closure, external plication, pledgeted closure, and patch closure. In one report of postoperative follow-up, the investigators emphasized the late development of pronounced aortic regurgitation through the native aortic valve in two thirds of the patients, necessitating reoperation.7Serino W Andrade JL Ross D de Leval M Somerville J Aorto-left ventricular communication after closure: late postoperative problems.Br Heart J. 1983; 49: 501-506Crossref PubMed Scopus (61) Google Scholar Those authors further suggested the need to reinforce and support the right aortic sinus at the time of initial closure of the tunnel to prevent this late complication. Surgical closure should be attempted as soon as the diagnosis is established. Although most authors recommend cardiac catheterization for diagnosis of this lesion, many of these cases are misdiagnosed as aortic stenosis with insufficiency or a ruptured aneurysm of the sinus of Valsalva. In addition, at least one death resulted when concomitant severe aortic stenosis was missed, presumably because the catheter slipped through the tunnel.8Cooley RN Harris LC Rodin AE Abnormal communication between the aorta and left ventricle: aortico-left ventricular tunnel.Circulation. 1965; 31: 564-571Crossref PubMed Scopus (32) Google Scholar Previous reports have established the utility and precision of diagnosis of aortico-left ventricular tunnel by use of real-time two-dimensional and pulsed-wave Doppler echocardiography.9Perry JC Nanda NC Hicks DG Harris JP Two-dimensional echocardiographic identification of aortico-left ventricular tunnel.Am J Cardiol. 1983; 52: 913-914Abstract Full Text PDF PubMed Scopus (11) Google Scholar, 10Fripp RR Werner JC Whitman V Nordenberg A Waldenhausen JA Pulsed Doppler and two-dimensional echocardiographic findings in aortico-left ventricular tunnel.J Am Coll Cardiol. 1984; 4: 1012-1014Abstract Full Text PDF PubMed Scopus (29) Google Scholar, 11Bash SE Huhta JC Nihill MR Vargo TA Hallman GL Aortico-left ventricular tunnel with ventricular septal defect: two-dimensional/Doppler echocardiographic diagnosis.J Am Coll Cardiol. 1985; 5: 757-760Abstract Full Text PDF PubMed Scopus (22) Google Scholar We also found these techniques helpful in the diagnosis of this rare lesion. The addition of color flow Doppler imaging to this diagnostic regimen provides a reproducible confirmation of the source of the to-and-fro blood flow in the tunnel, which is distinct from the flow through the aortic valve. This feature is a clear advantage over angiographic techniques, which are affected by opacification of adjacent structures and loss of border outline and thus depend on precise positioning of the patient. Echocardiography may also be helpful in detecting other associated cardiac defects. Magnetic resonance imaging adds yet another dimension to the diagnostic imaging of this lesion. The still-frame images produced by this procedure clearly demonstrate the abnormal cardiovascular anatomy of this malformation. In addition, magnetic resonance imaging provides useful information about the relationship of the tunnel to adjacent structures. The current case demonstrates an example of aortico-left ventricular tunnel in which multiple diagnostic modalities were used. The utility of two-dimensional echocardiography with pulsed-wave, continuous-wave, and color flow Doppler imaging is demonstrated. Magnetic resonance imaging provides a unique picture of this rare lesion with its relationships to adjacent cardiac and mediastinal structures. The diagnosis of aortico-left ventricular tunnel can be established by several noninvasive methods. Unless other concomitant cardiac lesions must be evaluated, cardiac catheterization may be unnecessary. Surgical closure of the defect is usually the treatment of choice. Long-term follow-up of these patients is important for the detection of the development of late complications—in particular, aortic valve stenosis or insufficiency.