HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Eldad Erez Vincent K.H. Tam Kirk R. Kanter Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Erez, E. Articles by Fyfe, D. A. Search for Related Content PubMed PubMed Citation Articles by Erez, E. Articles by Fyfe, D. A. Related Collections Congenital - cyanotic

Ann Thorac Surg 2001;71:1974-1977
© 2001 The Society of Thoracic Surgeons

---

Original article: cardiovascular

Successful biventricular repair after initial Norwood operation for interrupted aortic arch with severe left ventricular outflow tract obstruction

^a Division of Cardiothoracic Surgery, Emory University School of Medicine, Atlanta, Georgia, USA
^b Division of Pediatric Cardiology, Emory University School of Medicine, Atlanta, Georgia, USA

Address reprint requests to Dr Tam, Emory Clinic, Section Cardiothoracic Surgery, 1365 Clifton Rd NE, Atlanta, GA 30322
e-mail: vtam01{at}emory.edu

Presented at the Poster Session of the Thirty-sixth Annual Meeting of The Society of Thoracic Surgeons, Fort Lauderdale, FL, Jan 31–Feb 2, 2000.

	Abstract

Top Abstract Introduction Patients and methods Results Comment References

 
Background. Management of newborns with interrupted aortic arch (IAA) remains challenging. Associated severe left ventricular outflow tract obstruction (LVOTO) have often led to increased mortality with neonatal biventricular repair. We review our experience with an alternative approach for this complex surgical problem.

Methods. From May 1991 to June 1999, 28 neonates were treated for IAA. Thirteen of 28 neonates (46%) had type B IAA, ventricular septal defect (VSD) and severe LVOTO (Z value –2 to –7; mean –5 ± 1.7). Mean age was 8 days (3 to 23 days old) with average weight of 3.3 kg (2.4 to 4.2 kg). Eight of 13 (62%) had anomalous right subclavian artery. Ten of 13 (77%) had thymic aplasia and chromosome 22 region q11 deletion. All 13 patients were treated initially with a modified Norwood procedure.

Results. There were no perioperative deaths. Complications included 2 patients with recurrent arch stenosis treated with balloon dilatation. Two patients had systemic arterial shunt revision. Follow-up ranged from 2 to 99 months old (mean 39 months). There were 2 late deaths unrelated to any operation. Nine of 12 patients had a second stage palliation consisting of a bidirectional Glenn shunt. Six patients went on to have biventricular repairs (3 Ross-Konno, 2 Rastelli, 1 VSD closure with LVOT resection). One patient had a modified Fontan operation and 5 patients are awaiting potential biventricular repair.

Conclusions. Children with IAA and severe LVOTO may be managed by initial Norwood palliation with an excellent outcome likely. This initial "univentricular" approach has enabled eventual successful biventricular repair despite severe LVOTO.

	Introduction

Top Abstract Introduction Patients and methods Results Comment References

 
Interrupted aortic arch (IAA) is a rare congenital heart defect usually diagnosed in the neonatal period. Associated left ventricular outflow tract obstruction (LVOTO) is not an uncommon problem that can often complicate biventricular repair of IAA and ventricular septal defect (VSD). Severe LVOTO is usually multilevel, involving the aortic valve, and subvalve muscular outflow tract. When severe outflow tract obstruction is present, it may be rarely associated with mitral valve hypoplasia and left ventricular hypoplasia. Severe LVOTO has been well recognized as an important risk factor for early and late morbidity and mortality with neonatal biventricular repair [1–4]. In the subset of children with IAA and significant LVOTO, optimal surgical management is still unclear. Should it be a single stage biventricular repair with significant risk for mortality or should the repair be a staged approach exposing the patient to multiple interventions? We review our experience with an alternate staged approach for this complex surgical problem.

	Patients and methods

Top Abstract Introduction Patients and methods Results Comment References

 
Between May 1991 and July 1999, 28 neonates with interrupted aortic arch were treated at the Egleston Hospital, Children’s Healthcare of Atlanta. A subgroup of 13 neonates (46%) had the diagnosis of IAA type B, ventricular septal defect, and LVOTO. The subaortic area Z values ranged from –2 to –7 (mean –5 ± 1.7) [5]. Age at operation ranged from 3 to 23 days (mean 7.2 ± 6 days) and weight ranged from 2.4 to 4.2 kg (mean 3.3 ± 0.4 kg). Because of concerns regarding the (LVOT), the treating physicians chose to apply a staged approach rather than neonatal biventricular repair in these 13 patients.

Associated cardiac lesions were as follow: 8 of 13 patients (62%) had anomalous right subclavian artery originating from the descending thoracic aorta, 5 of 13 patients (38%) had bicuspid aortic valve, one patient had interrupted inferior vena cava (IVC) with azygos continuation, and 1 patient had anomalous origin of the right subclavian artery from the right pulmonary artery.

Noncardiac lesions were found in 10 of 13 patients (76%) who had chromosome 22 region q11 deletion. Five of these 10 patients had DiGeorge syndrome (absent thymus gland, reduced peripheral blood T-lymphocyte count, and hypocalcemia).

The diagnosis and assessment of the subaortic region, left ventricular (LV), and aortic dimensions were all made using echocardiographic measurements. A single observer, as part of this study, retrospectively reviewed these echocardiographic tapes (Table 1). All left ventricular dimensions were in the normal range except for one patient who had small mitral and aortic valves. LV volume was calculated using the formula, 0.83 x LV length x 3.14r² and indexed to the body surface area. Normal LV volume was defined as greater than 20 ml/m² [6]. The LVOT Z value represents the number of standard deviations from the mean and was calculated using previously generated regression normograms [5].

	Results

Top Abstract Introduction Patients and methods Results Comment References

 
There were no perioperative deaths, follow-up ranged from 2 to 99 months (mean 39 months). Two patients had late arch stenosis treated successfully by balloon dilatation. Two patients had systemic arterial shunt revision, with addition of a left modified Blalock-Taussig shunt in one patient, during the first month after the Norwood operation. The one patient who had subaortic myomectomy with VSD closure, as his biventricular repair, had repeat operation for recurrent subaortic stenosis. There were two late deaths from noncardiac causes. Both patients had DiGeorge syndrome and succumbed to septic complications. The first patient died at the age of 6 months after successful Norwood operation, despite a good hemodynamic outcome. The second patient died from pneumonia and sepsis at the age of 2.5 years, 6 months after he had completed biventrivular repair using the Ross-Konno technique.

6 patients have completed biventricular repair (3 Ross-Konno, 2 Rastelli, 1 VSD closure and LVOT resection). Nine patients had a second stage palliation consisting of a bidirectional Glenn shunt. Three of these 9 had Ross-Konno biventricular repair, 1 patient had modified Fontan and 5 await potential biventricular repair (Fig 1).

View larger version (10K): [in this window] [in a new window]   Fig 1. Staged surgical approach.

	Comment

Top Abstract Introduction Patients and methods Results Comment References

There are several methods commonly used in assessing the size of the LVOT and the severity of obstruction. Most centers rely on echocardiographic techniques, measuring the subaortic diameter in the parasternal long axis view with or without standardization to patient size [5, 12, 13]. However, none of these echocardiographic measurements have been shown to predict survival or reoperation after neonatal biventricular repair. Lack of standardization of measurements, difficulty in accurately measuring the subaortic area and difficulty in timing measurements during the cardiac cycle have contributed to the variability and inconsistency from institution to institution in assessing the LVOT [12]. These diagnostic problems have confounded the comparison of small series of patients from different institutions.

In most reports on IAA repair, LVOTO is the principal reason for early and late deaths as well as subsequent reoperation [1–4]. In the large multi-institutional study reported by Jonas, not only was failure to address the LVOTO during operation a risk factor for death after repair, but some surgical techniques designed to correct the LVOTO were also associated with high mortality. Subaortic myotomy/myectomy or a Damus-Kaye-Stancel anastomosis carried a mortality rate of 47% and 91%, respectively [1]. Since that study, several authors have reported improved results with this complex problem. Luciani and colleagues [9] reported a novel single stage approach involving 9 neonates with IAA and severe LVOTO. Repair was accomplished by closing the VSD through the pulmonary valve and placement of the cephalad end of the VSD patch on the left side of the conal septum without myomectomy. There were no mortality and no recurrence of LVOTO during their short-term follow-up. However, 4 patients had significant residual VSDs, prompting questions regarding technical aspects of this approach. A second study from the same group addressed successful management of recurrent LVOTO in 3 infants by the Ross-Konno technique [14]. Bove and associates [15] suggested (based on a group of 7 patients) that in neonates with VSD and severe LVOTO, direct relief can be satisfactorily accomplished by myectomy of the conal septum up to the aortic valve through the right atrium. Jacobs and colleagues [2] were the first to address this complex problem by staged approach using the Norwood procedure. Analysis of survival in relation to method of initial repair revealed that staged repair was associated with improved short-term survival (100% versus 77% at 1 month; 89% versus 77% at 6 months and at 12 months, staged versus one stage). A recent study by Ohye and colleagues [16] reported a combined repair for a similar group of 20 patients using modified Norwood and Rastelli procedures, either as a single or staged repair. Five-year actuarial survival for the staged approach was 89% versus 73% for the neonatal repair group (not statistically significant). An interesting study by Fulton and associates [17] reported that LVOTO was not a significant risk factor for hospital death or late death with IAA. In their study, 36 of 72 patients (50%) were defined as having LVOTO, but only 15 patients (21%) had LVOT enlargement with their initial operation. Nine patients needed subsequent reoperation for LVOTO. During their follow-up, 22 patients had echo-Doppler evidence for LVOTO with more than a 40 mm Hg LVOT gradient seen in 5 patients.

In our patients with severe LVOTO, we have elected a staged approach leading ultimately to biventricular repair. What should the cutoff be for attempted neonatal biventricular repair? Seven of our 13 patients had a LVOT diameter Z value of -6 or less. This subgroup would undoubtedly have initial or subsequent, or both initial and subsequent, difficulty with LVOT obstruction, negatively impacting their survival after neonatal biventricular repair. On the other hand, the 1 patient who eventually had VSD closure and LVOT resection, with an initial LVOT Z value of –2, likely would have survived neonatal biventricular repair. Of interest, this patient underwent a third operation for recurrent LVOTO. We suspect the cutoff should probably be in the range of -5 or –6 LVOT Z value. Given our 100% survival, we believe these newborns will tolerate the initial modified Norwood operation very well. Using this approach allows us to delay our decision regarding the feasibility of a biventricular repair. Rarely (1 of 13 patients in our series), persistent mitral valve stenosis with LV hypoplasia will dictate continued single ventricular palliation. Questions regarding the adequacy of the mitral valve and LV would push us toward a univentricular approach.

Our surgical technique deserves further discussion. We believe management of the atrial septum is paramount in maintaining mitral valve and LV growth. Assuming the mitral valve is functionally adequate, a normal septum primum should be left undisturbed and allowed to close. If the septum primum is inadequate or severely fenestrated, resulting in an unrestricted atrial septal communication, consideration should be given to closing this atrial septal defect during the Norwood operation, to ensure normal LV inflow.

After the neonatal period, we have elected to further palliate 9 of 13 patients with takedown of the Blalock shunt and construction of a bidirectional Glenn shunt at 3 to 6 months of age. The bidirectional superior cavopulmonary shunt has proven to be a safe and effective palliation in many institutions. The several months delay until biventricular repair allows for placement of a larger right ventricle to pulmonary artery conduit, and may delay future reintervention. This intermediate step also allows for the regression in ventricular hypertrophy, which we believe contributes to the superior outcome of the eventual biventricular repair. Reconnection of the SVC to the right atrium, subsequently has not resulted in sinus node dysfunction. We have typically reanastomosed the SVC to a more anterior portion of the right atrium, using the remnant of the atrial appendage, away from the cavo-atrial junction and the sinus node.

Early in this series, we achieved staged biventricular repair using a modified Rastelli operation as a second stage operation similar to the approach presented recently by Ohye and associates [16]. As our experience has accumulated, we believe that the Ross-Konno technique is superior to a Rastelli-type operation. The Ross-Konno technique allows for enlargement and accurate tailoring of the LVOT, providing an anatomically and physiologically normal outlet for the left ventricle. On the other hand, it has been reported that the left ventricle undergoes geometric change after a Rastelli operation because the VSD is used as the new left ventricular outflow. These changes are manifested as increased left ventricular wall thickness, decreased cavity dimensions, and a decrease in VSD size that may cause recurrent LVOTO over time [18]. Given the typically large muscular outlet or conoseptal VSD, the risk of injuring the left ventricle is minimal. The bridge of infundibular septum along with the native aortic annulus may be divided without any risk of injuring major septal branches of the left anterior descending coronary artery. Once the pulmonary autograft is removed from the right ventricle, frequently a generous size pulmonary homograft will fit easily in the relaxed right ventricular outflow tract, thereby also providing for an anatomically and physiologically normal right ventricular outflow tract. No separate right ventriculotomy is necessary. Since the new right ventricular to pulmonary artery connection is largely in the normal anatomic position, distortion and compression of the conduit, which is sometimes seen after a Rastelli type operation, is avoided. Given the typically bulky Norwood neoaortic root, the modified Rastelli would place the right ventriculotomy nearly at the apex of the right ventricle. This pulmonary conduit would then take a more circuitous route to reach the branch pulmonary arteries because of the location and size of the Norwood neoaortic root. The major disadvantage of the Ross-Konno technique is that it is a more extensive procedure, requiring a significantly longer ischemic time, and consequently, a longer cardiopulmonary bypass time.

A glaring disadvantage to this staged approach is the multiple operations these children undergo. However, with proper selection, these children are likely the same children who would require additional operations later because of recurrent or residual LVOTO, if a simple initial biventricular approach had been taken. Norwood and other colleagues [7, 8] have successfully applied this operation to infants with IAA and severe LVOTO; it was criticized because it represents palliation leading to univentricular physiology rather than achieving early biventricular physiology. In our approach, this univentricular palliation is only an initial temporary step that enables eventual biventricular repair with low morbidity and mortality. This approach delays the decision regarding suitability of a biventricular repair in a favorable way. With growth and increased size, candidacy for biventricular repair is better determined. One patient of ours had persistent mitral stenosis that dictated further single ventricular palliation.

Finally, it is impossible to ignore the noncardiac lesions associated with type B IAA. Two children with DiGeorge syndrome suffered late deaths because of infectious complications, with both patients having severely impaired immune function. This associated noncardiac lesion is a cause for increased morbidity and mortality in IAA that is not directly related to surgery [19], and will negatively influence long-term outcome.

In conclusion, neonates with IAA and severe LVOTO may be managed by an initial modified Norwood operation with likely excellent outcome. This initial univentricular approach has enabled eventual successful biventricular repair despite severe LVOTO.

	References

Top Abstract Introduction Patients and methods Results Comment References

 

1. Jonas R.A., Quaegebeur J.M., Kirklin J.W., Blackstone E.H., Daicoff G. Outcomes in-patients with interrupted aortic arch and ventricular septal defect: a multiinstitutional study. Congenital Heart Surgery Society. J Thorac Cardiovasc Surg 1994;107:1099-1109.[Abstract/Free Full Text]
2. Jacobs M.L., Chin A.J., Rychik J., Steven J.M., Nicolson S.C., Norwood W.I. Interrupted aortic arch: impact of subaortic stenosis on management and outcome. Circulation 1995;92:II128-II131.
3. Menahem S., Rahayoe A.U., Brawn W.J., Mee R.B. Interrupted aortic arch in infancy: a 10-year experience. Pediatr Cardiol 1992;13:214-221.[Medline]
4. Serraf A., Lacour-Gayet F., Robotin M., et al. Repair of Interrupted aortic arch: a 10-year experience. J Thorac Cardiovasc Surg 1996;112:1150-1160.[Abstract/Free Full Text]
5. Anatomy, dimensions, and terminology. In: Kirklin JW, Barratt-Boyes BG, eds. Cardiac surgery. 2nd edition. New York: Churchill Livingstone, 1993:3–60.
6. Hammon J.W., Flavian L.M., Maples M.D., et al. Predictors of operative mortality in critical aortic stenosis presenting in infancy. Ann Thorac Surg 1988;18:1049-1055.
7. Kanter K.R., Miller B.E., Cuadrado A.G., Vincent R.N. Successful application of the Norwood procedure for infants without hypoplastic left heart syndrome. Ann Thorac Surg 1995;59:301-304.[Abstract/Free Full Text]
8. Jacobs M.L., Rychik J., Murphy J.D., Nicolson S.C., Steven J.M., Norwood W.I. Results of Norwood’s operation for lesions other than hypoplastic left heart syndrome. J Thorac Cardiovasc Surg 1995;110:1555-1562.[Abstract/Free Full Text]
9. Luciani G.B., Ackerman R.J., Chang A.C., Wells W.J., Starnes V.A. One-stage repair of interrupted aortic arch, ventricular septal defect, and subaortic obstruction in the neonate: a novel approach. J Thorac Cardiovasc Surg 1996;111:348-358.[Abstract/Free Full Text]
10. Bove E.L., Minich L.L., Pridjian A.K., et al. The management of severe subaortic stenosis, ventricular septal defect and interrupted aortic arch in the neonate. J Thorac Cardiovasc Surg 1993;105:289-295.[Abstract]
11. Allan L.D., Apfel H.D., Levenbrown Y., Quaegebeur J.M. Surgical repair of interrupted aortic arch with ventricular septal defect. Cardiol Young 1998;8:317-324.
12. Apfel H.D., Levenbrown Y., Quaegebeur J.M., Allan L.D. Usefulness of preoperative echocardiography in predicting left ventricular outflow obstruction after primary repair of interrupted aortic arch with ventricular septal defect. Am J Cardiol 1998;82:470-473.[Medline]
13. Blaufox A.D., Lai W.W., Lopez L., Nguyen K., Griepp R.B., Parness I.A. Survival in neonatal biventricular repair of left sided cardiac obstructive lesions associated with hypoplastic left ventricle. Am J Cardiol 1998;82:1138-1140.[Medline]
14. Starnes V.A., Luciani G.B., Wells W.J., Allen R.B., Lewis A.B. Aortic root replacement with the pulmonary autograft in children with complex left heart obstruction. Ann Thorac Surg 1996;62:442-449.[Abstract/Free Full Text]
15. Bove E.L., Minich L.L., Pridjian A.K., et al. The management of severe subaortic stenosis, ventricular septal defect, and aortic arch obstruction in the neonate. J Thorac Cardiovasc Surg 1993;105:289-296.
16. Ohye R.G., Kagisaki K., Lee L.A., Mosca R.S., Goldberg C.S., Bove E.L. Biventricular repair for aortic atresia or hypoplasia and ventricular septal defect. J Thorac Cardiovasc Surg 1999;118:648-654.[Abstract/Free Full Text]
17. Fulton J.O., Mas C., Brizard C.P.R., Cochrane A.D., Karl R.T. Does left ventricular outflow tract obstruction influence outcome in interrupted aortic arch repair?. Ann Thorac Surg 1999;67:177-181.[Abstract/Free Full Text]
18. Rychik J., Jacobs M.L., Norwood W.I. Early changes in ventricular geometry and ventricular septal defect size following Rastelli operation or intraventricular baffle repair for conotruncal anomaly: a cause for development of subaortic stenosis. Circulation 1994;90(5 Pt 2):II13-II19.
19. McDonald-McGinn D.M., Kirschner R., Goldmuntz E., et al. The Philadelphia story: the 22q11.2 deletion: report on 250 patients. Genet Couns 1999;10:11-24.[Medline]

This article has been cited by other articles:

				M. Nathan, D. Rimmer, P. J. del Nido, J. E. Mayer, E. A. Bacha, A. Shin, W. Regan, R. Gonzalez, and F. Pigula Aortic Atresia or Severe Left Ventricular Outflow Tract Obstruction with Ventricular Septal Defect: Results of Primary Biventricular Repair in Neonates Ann. Thorac. Surg., December 1, 2006; 82(6): 2227 - 2232. [Abstract] [Full Text] [PDF]

				B. W. McCrindle, C. I. Tchervenkov, I. E. Konstantinov, W. G. Williams, R. A. Neirotti, M. L. Jacobs, E. H. Blackstone, and For the members of the Congenital Heart Surgeons S Risk factors associated with mortality and interventions in 472 neonates with interrupted aortic arch: A Congenital Heart Surgeons Society study J. Thorac. Cardiovasc. Surg., February 1, 2005; 129(2): 343 - 350. [Abstract] [Full Text] [PDF]

				J. M. Pearl, L. W. Cripe, and P. B. Manning Biventricular repair after Norwood palliation Ann. Thorac. Surg., January 1, 2003; 75(1): 132 - 137. [Abstract] [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Eldad Erez Vincent K.H. Tam Kirk R. Kanter Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Erez, E. Articles by Fyfe, D. A. Search for Related Content PubMed PubMed Citation Articles by Erez, E. Articles by Fyfe, D. A. Related Collections Congenital - cyanotic