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Reverse subclavian flap repair of hypoplastic transverse aorta in infancy
Reverse Subclavian Flap Repair of Hypoplastic Transverse Aorta in Infancy Kirk R. Kanter, MD, Robert N. Vincent, MD, and Derek A. Fyfe, MD Division of Cardio-Thoracic Surgery, Department of Surgery, Emory University School of Medicine, and The Sibley Heart Center Children’s Healthcare of Atlanta at Egleston, Division of Pediatric Cardiology, Department of Pediatrics, Emory University School of Medicine, Atlanta, Georgia
Background. Management of hypoplastic aortic arch associated with coarctation in infancy can be challenging. Reverse subclavian flap aortoplasty plus coarctation resection offers simplicity without needing foreign material or cardiopulmonary bypass. Methods. Since 1988, 46 of 162 infants less than 3 months undergoing coarctation repair had hypoplastic arch enlargement with reverse subclavian flap aortoplasty. Median age was 11 days; mean weight was 3.2 kg. Thirty-seven patients (80%) had associated cardiac defects including single or multiple ventricular septal defects (14 infants), transposition of the great arteries (7), aortic or mitral stenosis (5), and complete atrioventricular septal defect (5 infants). Twenty-eight patients had pulmonary artery banding; 2 had an arterial switch operation through a separate median sternotomy. Results. There were two hospital deaths: one 4 months postoperatively in a patient requiring a Norwood procedure the next day for underestimated left ventricular hypoplasia; the other of sepsis more than 1 month postopera-
tively. On follow-up from 1 to 129 months (mean, 38 months), there were five recurrent obstructions: three at the coarctation site treated with balloon dilatation and two at the arch site. Twenty-six children had their heart defects corrected with 29 subsequent operations including an arterial switch operation for transposition of the great arteries/ ventricular septal defect (3 infants), relief of aortic or mitral stenosis ⴞ ventricular septal defect closure (5), multiple ventricular septal defect closure (3), a bidirectional Glenn (2), complete atrioventricular septal defect (2), and anomalous left coronary with ventricular septal defect repair (1 infant). Four children await debanding and ventricular septal defect closure or Glenn anastomosis. There have been two late deaths (overall survival, 91%). Conclusions. Reverse subclavian flap aortoplasty is excellent for relief of arch hypoplasia and coarctation in infants with low recurrence rates and acceptable operative and intermediate survival. (Ann Thorac Surg 2001;71:1530 – 6) © 2001 by The Society of Thoracic Surgeons
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distal transverse aorta. The distal transverse aorta was defined as the aorta between the left carotid artery and the left subclavian artery. It was considered hypoplastic if the internal diameter by preoperative echocardiogram or angiogram was less than 50% of the diameter of the distal ascending aorta proximal to the takeoff of the innominate artery [1], or if the diameter in millimeters was less than the patient’s weight in kilograms plus 1 [8] (Fig 1). Age at operation ranged from 3 to 91 days (mean, 17 ⫾ 20 days) with 41 patients younger than 30 days. Mean weight was 3.2 ⫾ 0.6 kg. The patients were divided into four categories according to associated cardiac anomalies (Table 1). Group I had 9 patients (20%) with isolated coarctation and arch hypoplasia with or without a patent ductus arteriosus. Group II consisted of 14 infants (30%) with an associated ventricular septal defect (VSD) only. Group III had 17 patients (37%) with more complex defects with two good-sized ventricles, and group IV had 6 children (13%) with univentricular physiology due to a hypoplastic left ventricle.
ypoplasia of the aortic arch is commonly associated with coarctation of the aorta in infants [1]. Various surgical techniques have been proposed to relieve the arch hypoplasia at the time of coarctation repair [2–5]. In 1975, Tiraboschi and colleagues [6] were the first to describe a reverse subclavian flap technique for repair of coarctation arising between the left carotid and left subclavian arteries. The reverse subclavian flap was used by Amato and associates [7] to enlarge the hypoplastic distal transverse aortic arch at the time of concomitant coarctation repair. We have modified this technique and have applied it to 46 infants with coarctation of the aorta and distal arch hypoplasia since 1988. This experience is the basis of this report.
Patients and Methods Definitions and Patients Since 1988, of 162 infants less than 3 months of age undergoing repair of aortic coarctation, 46 (28%) had reverse subclavian flap augmentation of a hypoplastic Presented at the Thirty-sixth Annual Meeting of The Society of Thoracic Surgeons, Fort Lauderdale, FL, Jan 31–Feb 2, 2000. Address reprint requests to Dr Kanter, Division of Cardiothoracic Surgery, Emory University School of Medicine, 1365 Clifton Rd, Atlanta, GA 30322; e-mail: [email protected].
© 2001 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
Operative Technique After initial resuscitation and stabilization with inotropic support and prostaglandin as needed, the infant was brought to the operating room. A right radial or axillary 0003-4975/01/$20.00 PII S0003-4975(01)02444-4
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Table 1. Groups Defined According to Associated Lesions (n ⫽ 46) Group
Number (%)
I. Isolated coarctation with hypoplastic arch 9 (20%) II. With VSD 14 (30%) Single 11 Multiple 3 III. With other biventricular heart disease 17 (37%) TGA ⫾ VSD or Taussig-Bing 7 AS or MS ⫾ VSD 5 CAVSD 2 ALCA/VSD 1 Congenitally corrected TGA/VSD/PS 1 DORV/VSD 1 IV. With other univentricular heart disease 6 (13%) Unbalanced CAVSD with hypoplastic LV 3 Hypoplastic LV 2 Mitral atresia/hypoplastic LV/multiple VSDs 1 ALCA ⫽ anomalous origin of the left coronary artery from the pulmonary trunk; AS ⫽ aortic stenosis (valvular or subvalvular); CAVSD ⫽ complete atrioventricular septal defect; DORV ⫽ double outlet right ventricle; LV ⫽ left ventricle; MS ⫽ mitral stenosis (valvular or supravalvular); PS ⫽ pulmonary stenosis; TGA ⫽ transposition of the great arteries; VSD ⫽ ventricular septal defect.
Fig 1. Aortogram from a representative case showing arch hypoplasia between the left carotid and left subclavian arteries with a tight aortic coarctation distal to the aortic isthmus.
arterial line was placed and the child was allowed to cool to 33°C during the initial stages of dissection. A standard left lateral thoracotomy incision was made and the pleural cavity entered through the third or fourth intercostal space. The hypoplastic transverse aorta was widely mobilized, as was the left carotid and subclavian arteries, the descending thoracic aorta, and the ductus arteriosus. It usually was not necessary to divide any intercostal arteries. Often, the left lobe of the thymus gland was resected to facilitate exposure. The dissection was extended proximally so that the proximal innominate artery was visualized. The distal left subclavian artery was now ligated at its first branching. The aortic isthmus was snared with a silicone elastomer tape between the left subclavian artery and the ductus arteriosus, thus allowing continued perfusion to the lower body through the patent ductus arteriosus (Fig 2). A clamp was carefully applied across the proximal transverse aorta between the innominate artery and the left carotid artery while insuring that the right radial (or axillary) arterial line trace was not dampened. Often, a pulse oximetry probe was placed on the right earlobe or cheek to monitor ongoing right common carotid artery perfusion. Although a C-shaped clamp could also encompass the proximal left carotid at the same time as the proximal arch, with experience we
found that a separate vascular clamp or bulldog clamp on the left carotid artery improved exposure of the angle between the left lateral aspect of the proximal left carotid artery and the superior aspect of the adjoining hypoplastic transverse arch (Fig 2). With careful clamp placement, we were able to use this technique even in children with a bovine-type aortic arch (the left carotid artery arising from the proximal innominate artery rather than sepa-
Fig 2. Surgical technique. Positioning of clamps and line of proposed incision (dashed line).
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disease other than isolated VSD) did not have a band placed. Two had an arterial switch procedure through a separate median sternotomy incision during the same anesthetic (one with, one without VSD closure). The other 2 patients without a band in this group had complex left ventricular outflow tract obstruction without a VSD in one and supravalvular mitral stenosis and subaortic stenosis with a restrictive VSD in the other. Only 1 child in the univentricular group IV did not have a band. The left ventricular hypoplasia was underestimated and this patients is discussed in more detail later.
Other Patients
Fig 3. Surgical technique. The left subclavian artery is flapped down onto the hypoplastic transverse aortic arch including the proximal left carotid artery.
rately from the aortic arch). The left subclavian artery was now divided proximal to the previously placed ligature and opened on its right medial aspect. This incision was carried along the superior aspect of the hypoplastic transverse aorta and then continued up for 3 to 4 mm onto the lateral aspect of the proximal left carotid artery (dashed line in Fig 2). The transected left subclavian artery was now flapped down onto the hypoplastic transverse arch. A stay suture on the crotch of the junction between the left carotid artery and the aortic arch greatly improved exposure (Fig 3). The subclavian flap was now sewn to the aortic arch starting at and including the proximal left carotid artery using continuous 7-0 polypropylene suture. The clamps were released and hemostasis achieved. In these patients, clamp time (and thus time of left carotid occlusion) was 16 ⫾ 5 minutes. After allowing the baby to recover somewhat, the ductus arteriosus was ligated. Clamps were placed on the newly enlarged transverse aorta (not including the left carotid artery) and the descending thoracic aorta. The coarctation segment including all visible ductal tissue was excised and a generous oblique end-to-end anastomosis using 7-0 polypropylene suture was constructed between the undersurface of the newly enlarged transverse aorta and the descending thoracic aorta (Fig 4). The average clamp time for this portion of the procedure was 16 ⫾ 3 minutes. Twenty-eight of the 46 children (61%) had pulmonary artery banding. All 9 patients in group I with isolated coarctation and hypoplastic arch did not have a band placed. Four of the 14 in group II (additional VSD only) did not have a band because the VSD was restrictive. Four of the 17 patients in group III (biventricular heart
During this same time period, 8 other infants aged 16 ⫾ 18 days underwent isolated standard subclavian flap repair of aortic coarctations. In 7, at the time of operation, after the coarctation repair, an unacceptable gradient was measured across the transverse aorta and the previously unrecognized hypoplastic transverse aorta was enlarged with a patch of polytetrafluoroethylene or pericardium at the same operation. An eighth patient who had an arterial switch procedure through a separate median sternotomy during the same anesthetic as his standard subclavian flap coarctation repair developed evidence of arch obstruction. He required reoperation to enlarge his hypoplastic transverse aortic arch at 80 days of age.
Follow-up and Restenosis After hospital discharge, all survivors were followed with routine cardiology appointments including upper and lower extremity blood pressure determinations and periodic echocardiograms. Cardiac catheterization was performed if there was a suspicion of recurrent arch obstruction or coarctation (defined as a gradient of ⱖ 20 mm Hg),
Fig 4. Surgical technique. After ligation of the ductus arteriosus, the coarctation segment with all visible ductal tissue is excised and an end-to-end anastomosis is fashioned.
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in anticipation of surgical repair of other defects, or if the clinical situation could not be defined accurately by less invasive techniques.
Table 2.
Statistical Methods
Operation
Values are shown as mean ⫾ standard deviation. Actuarial survival was performed using a Kaplan-Meier analysis.
Results Early Mortality Although 30-day mortality in this series was zero, there were two deaths before hospital discharge (operative survival, 96%). One infant mentioned previously, who preoperatively had what was believed to be a marginal but acceptable left ventricle, had a reverse subclavian flap repair of his hypoplastic aortic arch with coarctation resection and end-to-end anastomosis. Because of borderline hemodynamics, echocardiogram and cardiac catheterization were performed the next day, which showed a small left ventricle with an end-diastolic pressure of 25 mm Hg. He then was converted over to a first-stage Norwood procedure. His postoperative course was plagued by intermittent bloodstream infections despite good hemodynamics and a satisfactory Norwood palliation by postoperative cardiac catheterization. He eventually succumbed to sepsis almost 4 months postoperatively without ever leaving the hospital. The other death was due to Candida sepsis 5 weeks postoperatively in a patient who had an arterial switch procedure with VSD closure at the time of repair of his aortic arch and coarctation. He, too, died before hospital discharge.
Restenosis The 44 survivors have been followed a mean of 38 months (range, 1 month to 10.8 years). There have been five recurrent obstructions (defined as a gradient ⱖ 20 mm Hg by arm/leg pressures, echocardiogram, or cardiac catheterization) ranging from 2.6 to 7.2 months postoperatively (mean, 4.9 months). Three were stenoses occurring at the site of end-to-end anastomosis; all three were successfully managed with percutaneous balloon dilatation. There were two recurrent arch obstructions. One was successfully balloon dilated 6 months postoperatively. The other child had a 30 mm Hg gradient across the proximal aortic arch between the innominate artery and left carotid artery at catheterization 1 month postoperatively. This required pericardial patch enlargement using profound hypothermia and circulatory arrest 4 months postoperatively. Interestingly, at operation, a mildly obstructive bar of fibrous tissue was excised from the lumen of the aorta at the most proximal site of the reverse subclavian flap. Presumably, this tissue was caused by inadvertently catching the back wall of the aorta when constructing the most proximal portion of the reverse subclavian flap anastomosis stressing the importance of clear exposure of the angle between the left carotid artery
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Subsequent Operations by Diagnostic Group
I. Isolated coarctation with hypoplastic arch (n ⫽ 9) II. With VSD (n ⫽ 14) Close VSD/deband Repair recurrent arch obstruction III. With other biventricular heart disease (n ⫽ 17) Arterial switch procedure/VSD closure CAVSD repair Aortic valvotomy/VSD closure Mitral ring ⫾ VSD closure Mitral valve replacement ALCA/VSD Other IV. With other univentricular heart disease (n ⫽ 6) Glenn anastomosis/DSK Norwood procedure
Number of Patients With Operations 0 10 9 1 14a 3 2 2 2 1 1 3 3 2b 1
a Does not include the 2 patients who had an arterial switch procedure at b One patient with a subsethe time of their arch/coarctation repair. quent Fontan procedure.
ALCA ⫽ repair of anomalous left coronary artery arising from pulmonary trunk; CAVSD ⫽ complete atrioventricular septal defect; DSK ⫽ modified Damus-Stansel-Kaye procedure; VSD ⫽ ventricular septal defect.
and the hypoplastic transverse aortic arch during this anastomosis. Actuarial freedom from recoarctation in this series was 86% ⫾ 14% after 7 months since there have been no episodes of recoarctation recognized after this time.
Subsequent Operations There have been 29 subsequent operations in 27 children (Table 2). None of the 9 children with isolated coarctation with arch hypoplasia have required further surgical intervention. Of the 14 patients in the group with only an associated VSD, 9 of the 10 with pulmonary artery banding have had the band removed with VSD closure (including 3 with multiple VSDs) 7.4 ⫾ 9.0 months after the original operation (range, 1 to 30 months). One patient still awaits pulmonary artery debanding and VSD closure. Fourteen of the 17 patients in the group with biventricular heart disease have had subsequent operations 7.7 ⫾ 10.8 months (range, 1 to 41 months) after the initial arch/coarctation repair (Table 2). Of the remaining 3 patients, 2 had an arterial switch procedure at the time of the original operation and 1 with congenitally corrected transposition of the great arteries, VSD, and mild pulmonary stenosis is awaiting repair and removal of his pulmonary artery band. Three of the 6 patients in the group with univentricular heart disease have had subsequent operations including the infant who had a first-stage Norwood procedure the
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day after his arch/coarctation repair (Table 2). The other 3 patients are awaiting a bidirectional Glenn anastomosis in preparation for an eventual Fontan procedure.
Late Survival There have been two late deaths 3 and 4 months after arch/coarctation repair, both in patients with severe systemic ventricular hypertrophy. One was in an infant with severe left ventricular outflow tract obstruction due to accessory mitral valve tissue. She suffered a cardiac arrest on induction of anesthesia for mitral valve replacement and could never be weaned from cardiopulmonary bypass postoperatively despite 10 days of support with extracorporeal membrane oxygenation. The other child with unbalanced complete atrioventricular septal defect, hypoplastic left ventricle, and a restrictive ventricular communication died 9 days after a bidirectional Glenn anastomosis and modified Damus-Stansel-Kaye procedure due to clotting of his Glenn anastomosis, probably related to marginally low cardiac output. Overall survival in this entire series of 46 infants was, therefore, 91% on follow-up of 36 ⫾ 35 months (range, 1 month to 10.8 years).
Comment Hypoplasia of the transverse aortic arch is commonly associated with coarctation of the aorta in infancy with incidences ranging from 32% to 81% [9, 10]. Using the definition of hypoplastic arch described by Moulaert [1] or Karl [8] and their colleagues, we identified 46 infants of 162 (28%) neonates undergoing coarctation repair who had hypoplasia of the aortic arch between the left carotid artery and the left subclavian artery. These infants underwent reverse subclavian flap repair of the hypoplastic aortic arch at the time of coarctation repair. There are some who contend that it is unnecessary to repair the hypoplastic arch as it will grow with time [11, 12]. Careful reading of these reports, however, reveals possible flaws in the analysis of the data presented. Siewers and colleagues [11] described 33 of 102 (32%) infants with coarctation with associated arch hypoplasia that was not addressed surgically at the time of coarctation repair. At a mean interval of 39 ⫾ 29 months postoperatively, evaluation of the transverse arch showed good growth. However, only 18 of the original 33 patients underwent reevaluation by imaging (presumably the remainder had no arm/leg pressure gradients). There were 3 early and 12 late deaths, although they state that “there was no evidence that the arch hypoplasia itself in any way contributed to the late deaths.” Another article commonly cited as evidence for growth of the hypoplastic transverse aorta after coarctation repair is by Myers and colleagues [12]. Careful reading of this article reveals that they believe a priori that “tubular hypoplasia of the aortic arch proximal to the left subclavian artery require[s] augmentation . . .; therefore, these patients [were] not included in [that] series.” On the other hand, there is reasonable evidence that the hypoplastic aortic arch should be repaired at the time
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of coarctation repair. Early reports show that the presence of arch hypoplasia is an independent risk factor for early mortality after coarctation repair with all 5 patients with arch hypoplasia in the series by Herrmann and associates [13] and 3 of 4 patients with arch hypoplasia in the series by Baudet and Al-Qudah [14] dying early after coarctation repair. Qu and colleagues [15] reported that of 23 infants younger than 6 months undergoing coarctation repair, 5 of the 6 infants with arch hypoplasia (defined as distal arch outer diameter ⬍ 3.9 mm) required arch augmentation. Our own experience is in agreement with these findings. During the same time period of this study, we encountered 8 infants with coarctation who initially underwent only standard subclavian flap repair. They then required augmentation of the aortic arch during this same operation (7 patients) or during a second operation 3 months later (1 patient). Further evidence that the hypoplastic arch does not always grow after coarctation repair is demonstrated by DeLeon and colleagues [16] who reported 6 patients requiring repair of arch hypoplasia late after successful coarctation repair. Even more compelling is the report by Poirier and associates [17] in which 27 patients with previous coarctation repair required subsequent surgical enlargement of a hypoplastic aortic arch. Finally, Machii and Becker [18] examined autopsy specimens of hypoplastic aortic arches and found fewer ␣-actin-positive cells that could indicate a diminished growth potential. Other than these anatomic reasons for repairing the hypoplastic arch at time of coarctation repair, there are convincing physiologic reasons succinctly enumerated by Vouhe´ and colleagues [10]. They argued that any residual arch gradient, even slight, would be poorly tolerated in an infant with preoperatively depressed ventricular function. Second, if there were coexisting left ventricular outflow tract obstruction, an incremental increase in left ventricular work caused by an unrepaired aortic arch would be detrimental. Finally, in patients who undergo concomitant pulmonary artery banding, any unrelieved arch gradient would effectively result in biventricular obstruction. Once one decides it is important to repair the hypoplastic aortic arch at the time of coarctation repair, there are a variety of available surgical techniques. These include the use of a left carotid artery flap [2, 4], resection with extended end-to-end anastomosis [3, 19, 20], repair through a midline sternotomy [8], and use of the left subclavian artery as a free flap [5]. In this series, we have used the left subclavian artery as a viable autologous flap to augment the hypoplastic aortic arch followed by coarctation resection with end-toend anastomosis (Figs 2 to 4). Tiraboschi and colleagues [6] first described the use of a reverse subclavian flap for repair of an unusual coarctation located between the left carotid and left subclavian arteries which was also described later by Hart and Waldhausen [21]. Amato and associates [7] depicted a side-to-side anastomosis between the left carotid and left subclavian arteries augmenting the hypoplastic aortic arch without transecting the subclavian artery distally. The coarctation was re-
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sected with end-to-end anastomosis during the same clamp period. Interestingly, Amato and coworkers [22] later reported a 30% early recoarctation rate with this technique. The modifications we have made with our technique for reverse subclavian flap aortoplasty are important. First, the arch is repaired during a clamp application separate from that used for the coarctation repair (Fig 2). This allows continued perfusion to the lower half of the body through the patent ductus arteriosus. Thus, not only are the spinal cord, kidneys, and viscera protected, but also the amount of cardiac afterload is dramatically reduced as compared to placing a clamp on the proximal aorta between the innominate artery and the left carotid artery at the same time the patent ductus arteriosus is ligated. Second, our technique should minimize the period of left carotid artery clamping as it remains open during the second stage of the repair when the coarctation is resected with end-to-end anastomosis (Fig 4). Although this consideration may be theoretical, there are reports of neurologic complications with extended endto-end repair of coarctation [23], which often is associated with longer carotid occlusion times than described with our technique. Finally, we stress the importance of dividing the left subclavian artery distally. This not only increases the amount of tissue available for arch augmentation, but also allows a tension-free anastomosis (Fig 3) as opposed to the Amato technique with its relatively high recurrence rate [22]. The operative survival in our series of 96% and the intermediate survival of 91% in a fairly heterogeneous group of patients is comparable to or better than survival reported with other techniques for repair of hypoplastic aortic arch with coarctation in infancy [8, 10, 23]. Also our actuarial freedom from restenosis rate of 86% past 7 months up to 10.8 years is respectable compared with other published reports [10, 22, 23]. On reflection, we believe that all three restenoses at the coarctation repair site almost certainly were due to inadequate resection of ductal tissue and thus were technical errors. One of the two arch obstructions was actually not a restenosis but rather uncorrected hypoplasia of the proximal aorta between the innominate artery and the left carotid artery, which of course is not addressed with this surgical technique. Finally, of late there has been interest in simultaneous correction of underlying heart defects at the time of repair of the hypoplastic aortic arch and coarctation arguing that the one-stage approach affords superior results [8]. Thirty-seven of the 46 patients in this series (80%) had additional heart lesions other than the aortic abnormalities. Yet only 2 patients in this series had simultaneous correction of the heart defects (both had an arterial switch procedure through a separate sternotomy). One of these patients accounted for one of the two hospital deaths (Candida sepsis 5 weeks postoperatively). On the other hand, 27 of our patients went on to a staged surgical repair with reasonable results. It could be argued that the only two deaths in these
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patients would not likely have been avoided by a onestage approach. In summary, we have presented a series of 46 infants with coarctation of the aorta and associated arch hypoplasia treated with reverse subclavian flap aortoplasty and resection of the coarctation with end-to-end anastomosis. This technique is technically simple and effective with low operative and intermediate mortality and good freedom from restenosis. Good relief of the arch obstruction allows later correction of heart defects with acceptable results.
References 1. Moulaert AJ, Bruins CC, Oppenheimer-Dekker A. Anomalies of the aortic arch and ventricular septal defects. Circulation 1976;53:1011–5. 2. Allen RG, Maria-Garcia J, Nayek G. Methods of management and results following surgery for coarctation of the aorta in infancy. J Ped Surg 1980;15:953– 60. 3. Zannini L, Lecompte Y, Galli R, et al. Aortic coarctation with hypoplasia of the arch: description of a new surgical technic. G Ital Cardiol 1985;15:1045– 8. 4. Mellgren G, Friberg LG. A new surgical technique for newborn children with coarctation of the aorta and critical hypoplasia of the aortic arch. Scand J Thorac Cardiovasc Surg 1994;28:49–53. 5. Kubota H, Camilleri L, Legault B, et al. Surgical correction of the hypoplastic aortic arch by the subclavian free flap method in the neonate. J Thorac Cardiovasc Surg 1998;116:519–21. 6. Tiraboschi R, Locatelli G, Bianchi T, Parenzan L. Correction of coarctation of the aorta during the first year of life by means of the subclavian flap technique. 8 cases operated on successfully. Surg Italy 1975;5:244–52. 7. Amato JJ, Rheinlander HF, Cleveland RJ. A method of enlarging the distal transverse arch in infants with hypoplasia and coarctation of the aorta. Ann Thorac Surg 1977;23:261–3. 8. Karl TR, Sano S, Brawn W, Mee RBB. Repair of hypoplastic or interrupted aortic arch via sternotomy. J Thorac Cardiovasc Surg 1992;104:688–95. 9. Morrow WR, Huhta JC, Murphy DJ Jr, McNamara DG. Quantitative morphology of the aortic arch in neonatal coarctation. J Am Coll Cardiol 1986;8:616–20. 10. Vouhe´ PR, Trinquet F, Lecompte Y, et al. Aortic coarctation with hypoplastic aortic arch. Results of extended end-to-end aortic arch anastomosis. J Thorac Cardiovasc Surg 1988;96: 557– 63. 11. Siewers RD, Ettedgui J, Pahl E, Tallman T, del Nido PJ. Coarctation and hypoplasia of the aortic arch: will the arch grow? Ann Thorac Surg 1991;52:608–14. 12. Myers JL, McConnell BA, Waldhausen JA. Coarctation of the aorta in infants: does the aortic arch grow after repair? Ann Thorac Surg 1992;54:869–75. 13. Herrmann VM, Laks H, Fagan L, Terschluse D, Willman VL. Repair of aortic coarctation in the first year of life. Ann Thorac Surg 1978;25:57– 63. 14. Baudet E, Al-Qudah A. Late results of the subclavian flap repair of coarctation in infancy. J Cardiovasc Surg 1989;30: 445–9. 15. Qu R, Yokota M, Kitano M, et al. Surgical indication for aortic arch hypoplasia in infants. J Cardiovasc Surg 1990;31: 796 – 800. 16. DeLeon MM, DeLeon SY, Quinones JA, et al. Management of arch hypoplasia after successful coarctation repair. Ann Thorac Surg 1997;63:975– 80. 17. Poirier NC, Van Arsdell GS, Brindle M, et al. Surgical treatment of aortic arch hypoplasia in infants and children with biventricular hearts. Ann Thorac Surg 1999;68: 2293–7. 18. Machii M, Becker AE. Hypoplastic aortic arch morphology
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pertinent to growth after surgical correction of aortic coarctation. Ann Thorac Surg 1997;64:516–20. 19. Lansman S, Shapiro AJ, Schiller MS, et al. Extended aortic arch anastomosis for repair of coarctation in infancy. Circulation 1986;74(Suppl 1):37– 41. 20. Elliott MJ. Coarctation of the aorta with arch hypoplasia: improvements on a new technique. Ann Thorac Surg 1987; 44:321–3. 21. Hart JC, Waldhausen JA. Reversed subclavian flap angio-
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plasty for arch coarctation of the aorta. Ann Thorac Surg 1983;36:715–7. 22. Amato JJ, Galdieri RJ, Cotroneo JV. Role of extended aortoplasty related to the definition of coarctation of the aorta. Ann Thorac Surg 1991;52:615–20. 23. van Heurn LWE, Wong CM, Spiegelhalter DJ, et al. Surgical treatment of aortic coarctation in infants younger than three months: 1985 to 1990. J Thorac Cardiovasc Surg 1994;107: 74– 86.
DISCUSSION DR MARSHALL L. JACOBS (Philadelphia, PA): Doctor Kanter, I am interested in the group with single ventricles and arch hypoplasia, a group where there is always a question or suspicion of systemic ventricular outflow tract obstruction. With the superb results that you have had at your institution with the Norwood operation, how did you differentiate these patients to manage them by arch augmentation and pulmonary artery banding? DR KANTER: Certainly if they had a hypoplastic ascending aorta, then we would use the Norwood technique. The key point was the measurement of the arch between the innominate artery and the carotid artery. If that was less than 60% of the ascending aorta, then we would go ahead with Norwood palliation rather than this technique. DR CHRISTOPHER J. KNOTT-CRAIG (Oklahoma City, OK): I enjoyed the presentation very much, and I was interested to note the heart catheterization visualizing the aorta in the one patient that you presented. Is this something that you do frequently? And if not, can you give us some idea about when you would encourage your cardiologist to catheterize an infant with coarctation? DR KANTER: No. As I said, this series started in 1988 and it dates back from then. Certainly during the past 8 or 10 years it has been terribly uncommon for us to take these children to the operating room with catheterization. We almost always go by echocardiogram alone. DR JOSEPH J. AMATO (Chicago, IL): Doctor Kanter, I congratulate you and your group on an excellent presentation and the wonderful results that you have achieved. I rise to tell you that I have encountered in my experience with repair of coarctation over 16 methods to repair coarctation of the aorta. This comes from the realization that there is a spectrum of entities that require tailoring the operation to the anatomy that the surgeon finds. Although the reverse subclavian flap for repair of the hypoplastic transverse aorta as you described is a highly effective method, it does sacrifice the function of the subclavian artery. I would propose that another method of repairing the hypoplastic arch is to use the extended end-to-end anastomosis as Zannini described in 1985 and Elliott further modified in 1987 using a radical extended end-to-end repair, which actually saves the subclavian artery as it lies over the anastomosis. Again, I congratulate you on your presentation. DR CARL L. BACKER (Chicago, IL): I also congratulate you, Kirk, very nice results. I think that this technique is something everyone should have in their armamentarium for that unusual patient that you can run into. This is another “trick” we can have up our sleeves. I rise mostly to remind and defend the technique of resection with extended end-to-end anastomosis. We presented our results with that that technique at this meeting 2 years ago. For the patient with a hypoplastic arch, much like you showed, I think
that that technique is useful. It is interesting that if you look at the series from Great Ormond Street (London) and Marie Lannelongue (Paris) (Leipzig, Germany), and then the series that Joe mentioned from Italy, there is probably over a thousand neonates from Europe that have been treated with the resection and extended end-to-end anastomosis, of whom probably 30 to 40% have a hypoplastic arch with really excellent results. When I reviewed that for our manuscript, the recurrence rate was about 5% to 10% with a similar low mortality to yours. And I think that in my mind this is becoming, at least at our institution, the procedure of choice. And it is a successful operation for the patient with a hypoplastic arch. I would also remind everyone that when you take the subclavian artery, although the risk is small, there is a risk of hand ischemia. And I was recently shown a case where the surgeon had required amputation of the arm following a subclavian flap. The other thing is that some of these patients— DR JACOBS: The surgeon or the patient? DR BACKER: Both! I remember when we did subclavian flaps routinely, a lot of times the baby’s arm would be quite cool and pale after this surgery, and I would be a little nervous, as a young attending. I wonder if you have seen any problems with hands being cool after this operation? Again, great results and I congratulate you on a nice presentation. DR KANTER: We certainly do see that the hands early on are cool and can sometimes be congested, but we have not had any difficulties with using the subclavian. I am not proposing that this method is to supplant the extended resection with end-to-end anastomosis, but an alternative to it. I don’t want this audience to believe that technique is not without its problems as well. In one large series there was a definite but small incidence of neurologic problems associated with it. The clamp times of the left carotid are clearly longer than with the technique that I have shown here. Although this difference may not be statistically different, all the reported series had longer clamp times than we found. Finally, if there is a technical error in that very proximal, most difficult part of the anastomosis, underneath the proximal aortic arch, then you have converted the patient to a much more difficult problem of proximal arch stenosis, which has to be dealt with from the front on bypass. DR KOZO ISHINO (Okayama, Japan): In terms of ischemic time during arch repair through median sternotomy, we perfuse the innominate artery or subclavian artery during arch repair, placing a cross-clamp between the innominate artery and left carotid artery, so that we can perform the arch repair with heart beating and brain perfusion as well. We have never encountered any neurological problem even in patients with hypoplastic aortic arch.
Background. Management of hypoplastic aortic arch associated with coarctation in infancy can be challenging. Reverse subclavian flap aortoplasty plus coarctation resection offers simplicity without needing foreign material or cardiopulmonary bypass. Methods. Since 1988, 46 of 162 infants less than 3 months undergoing coarctation repair had hypoplastic arch enlargement with reverse subclavian flap aortoplasty. Median age was 11 days; mean weight was 3.2 kg. Thirty-seven patients (80%) had associated cardiac defects including single or multiple ventricular septal defects (14 infants), transposition of the great arteries (7), aortic or mitral stenosis (5), and complete atrioventricular septal defect (5 infants). Twenty-eight patients had pulmonary artery banding; 2 had an arterial switch operation through a separate median sternotomy. Results. There were two hospital deaths: one 4 months postoperatively in a patient requiring a Norwood procedure the next day for underestimated left ventricular hypoplasia; the other of sepsis more than 1 month postopera-
tively. On follow-up from 1 to 129 months (mean, 38 months), there were five recurrent obstructions: three at the coarctation site treated with balloon dilatation and two at the arch site. Twenty-six children had their heart defects corrected with 29 subsequent operations including an arterial switch operation for transposition of the great arteries/ ventricular septal defect (3 infants), relief of aortic or mitral stenosis ⴞ ventricular septal defect closure (5), multiple ventricular septal defect closure (3), a bidirectional Glenn (2), complete atrioventricular septal defect (2), and anomalous left coronary with ventricular septal defect repair (1 infant). Four children await debanding and ventricular septal defect closure or Glenn anastomosis. There have been two late deaths (overall survival, 91%). Conclusions. Reverse subclavian flap aortoplasty is excellent for relief of arch hypoplasia and coarctation in infants with low recurrence rates and acceptable operative and intermediate survival. (Ann Thorac Surg 2001;71:1530 – 6) © 2001 by The Society of Thoracic Surgeons
H
distal transverse aorta. The distal transverse aorta was defined as the aorta between the left carotid artery and the left subclavian artery. It was considered hypoplastic if the internal diameter by preoperative echocardiogram or angiogram was less than 50% of the diameter of the distal ascending aorta proximal to the takeoff of the innominate artery [1], or if the diameter in millimeters was less than the patient’s weight in kilograms plus 1 [8] (Fig 1). Age at operation ranged from 3 to 91 days (mean, 17 ⫾ 20 days) with 41 patients younger than 30 days. Mean weight was 3.2 ⫾ 0.6 kg. The patients were divided into four categories according to associated cardiac anomalies (Table 1). Group I had 9 patients (20%) with isolated coarctation and arch hypoplasia with or without a patent ductus arteriosus. Group II consisted of 14 infants (30%) with an associated ventricular septal defect (VSD) only. Group III had 17 patients (37%) with more complex defects with two good-sized ventricles, and group IV had 6 children (13%) with univentricular physiology due to a hypoplastic left ventricle.
ypoplasia of the aortic arch is commonly associated with coarctation of the aorta in infants [1]. Various surgical techniques have been proposed to relieve the arch hypoplasia at the time of coarctation repair [2–5]. In 1975, Tiraboschi and colleagues [6] were the first to describe a reverse subclavian flap technique for repair of coarctation arising between the left carotid and left subclavian arteries. The reverse subclavian flap was used by Amato and associates [7] to enlarge the hypoplastic distal transverse aortic arch at the time of concomitant coarctation repair. We have modified this technique and have applied it to 46 infants with coarctation of the aorta and distal arch hypoplasia since 1988. This experience is the basis of this report.
Patients and Methods Definitions and Patients Since 1988, of 162 infants less than 3 months of age undergoing repair of aortic coarctation, 46 (28%) had reverse subclavian flap augmentation of a hypoplastic Presented at the Thirty-sixth Annual Meeting of The Society of Thoracic Surgeons, Fort Lauderdale, FL, Jan 31–Feb 2, 2000. Address reprint requests to Dr Kanter, Division of Cardiothoracic Surgery, Emory University School of Medicine, 1365 Clifton Rd, Atlanta, GA 30322; e-mail: [email protected].
© 2001 by The Society of Thoracic Surgeons Published by Elsevier Science Inc
Operative Technique After initial resuscitation and stabilization with inotropic support and prostaglandin as needed, the infant was brought to the operating room. A right radial or axillary 0003-4975/01/$20.00 PII S0003-4975(01)02444-4
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Table 1. Groups Defined According to Associated Lesions (n ⫽ 46) Group
Number (%)
I. Isolated coarctation with hypoplastic arch 9 (20%) II. With VSD 14 (30%) Single 11 Multiple 3 III. With other biventricular heart disease 17 (37%) TGA ⫾ VSD or Taussig-Bing 7 AS or MS ⫾ VSD 5 CAVSD 2 ALCA/VSD 1 Congenitally corrected TGA/VSD/PS 1 DORV/VSD 1 IV. With other univentricular heart disease 6 (13%) Unbalanced CAVSD with hypoplastic LV 3 Hypoplastic LV 2 Mitral atresia/hypoplastic LV/multiple VSDs 1 ALCA ⫽ anomalous origin of the left coronary artery from the pulmonary trunk; AS ⫽ aortic stenosis (valvular or subvalvular); CAVSD ⫽ complete atrioventricular septal defect; DORV ⫽ double outlet right ventricle; LV ⫽ left ventricle; MS ⫽ mitral stenosis (valvular or supravalvular); PS ⫽ pulmonary stenosis; TGA ⫽ transposition of the great arteries; VSD ⫽ ventricular septal defect.
Fig 1. Aortogram from a representative case showing arch hypoplasia between the left carotid and left subclavian arteries with a tight aortic coarctation distal to the aortic isthmus.
arterial line was placed and the child was allowed to cool to 33°C during the initial stages of dissection. A standard left lateral thoracotomy incision was made and the pleural cavity entered through the third or fourth intercostal space. The hypoplastic transverse aorta was widely mobilized, as was the left carotid and subclavian arteries, the descending thoracic aorta, and the ductus arteriosus. It usually was not necessary to divide any intercostal arteries. Often, the left lobe of the thymus gland was resected to facilitate exposure. The dissection was extended proximally so that the proximal innominate artery was visualized. The distal left subclavian artery was now ligated at its first branching. The aortic isthmus was snared with a silicone elastomer tape between the left subclavian artery and the ductus arteriosus, thus allowing continued perfusion to the lower body through the patent ductus arteriosus (Fig 2). A clamp was carefully applied across the proximal transverse aorta between the innominate artery and the left carotid artery while insuring that the right radial (or axillary) arterial line trace was not dampened. Often, a pulse oximetry probe was placed on the right earlobe or cheek to monitor ongoing right common carotid artery perfusion. Although a C-shaped clamp could also encompass the proximal left carotid at the same time as the proximal arch, with experience we
found that a separate vascular clamp or bulldog clamp on the left carotid artery improved exposure of the angle between the left lateral aspect of the proximal left carotid artery and the superior aspect of the adjoining hypoplastic transverse arch (Fig 2). With careful clamp placement, we were able to use this technique even in children with a bovine-type aortic arch (the left carotid artery arising from the proximal innominate artery rather than sepa-
Fig 2. Surgical technique. Positioning of clamps and line of proposed incision (dashed line).
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disease other than isolated VSD) did not have a band placed. Two had an arterial switch procedure through a separate median sternotomy incision during the same anesthetic (one with, one without VSD closure). The other 2 patients without a band in this group had complex left ventricular outflow tract obstruction without a VSD in one and supravalvular mitral stenosis and subaortic stenosis with a restrictive VSD in the other. Only 1 child in the univentricular group IV did not have a band. The left ventricular hypoplasia was underestimated and this patients is discussed in more detail later.
Other Patients
Fig 3. Surgical technique. The left subclavian artery is flapped down onto the hypoplastic transverse aortic arch including the proximal left carotid artery.
rately from the aortic arch). The left subclavian artery was now divided proximal to the previously placed ligature and opened on its right medial aspect. This incision was carried along the superior aspect of the hypoplastic transverse aorta and then continued up for 3 to 4 mm onto the lateral aspect of the proximal left carotid artery (dashed line in Fig 2). The transected left subclavian artery was now flapped down onto the hypoplastic transverse arch. A stay suture on the crotch of the junction between the left carotid artery and the aortic arch greatly improved exposure (Fig 3). The subclavian flap was now sewn to the aortic arch starting at and including the proximal left carotid artery using continuous 7-0 polypropylene suture. The clamps were released and hemostasis achieved. In these patients, clamp time (and thus time of left carotid occlusion) was 16 ⫾ 5 minutes. After allowing the baby to recover somewhat, the ductus arteriosus was ligated. Clamps were placed on the newly enlarged transverse aorta (not including the left carotid artery) and the descending thoracic aorta. The coarctation segment including all visible ductal tissue was excised and a generous oblique end-to-end anastomosis using 7-0 polypropylene suture was constructed between the undersurface of the newly enlarged transverse aorta and the descending thoracic aorta (Fig 4). The average clamp time for this portion of the procedure was 16 ⫾ 3 minutes. Twenty-eight of the 46 children (61%) had pulmonary artery banding. All 9 patients in group I with isolated coarctation and hypoplastic arch did not have a band placed. Four of the 14 in group II (additional VSD only) did not have a band because the VSD was restrictive. Four of the 17 patients in group III (biventricular heart
During this same time period, 8 other infants aged 16 ⫾ 18 days underwent isolated standard subclavian flap repair of aortic coarctations. In 7, at the time of operation, after the coarctation repair, an unacceptable gradient was measured across the transverse aorta and the previously unrecognized hypoplastic transverse aorta was enlarged with a patch of polytetrafluoroethylene or pericardium at the same operation. An eighth patient who had an arterial switch procedure through a separate median sternotomy during the same anesthetic as his standard subclavian flap coarctation repair developed evidence of arch obstruction. He required reoperation to enlarge his hypoplastic transverse aortic arch at 80 days of age.
Follow-up and Restenosis After hospital discharge, all survivors were followed with routine cardiology appointments including upper and lower extremity blood pressure determinations and periodic echocardiograms. Cardiac catheterization was performed if there was a suspicion of recurrent arch obstruction or coarctation (defined as a gradient of ⱖ 20 mm Hg),
Fig 4. Surgical technique. After ligation of the ductus arteriosus, the coarctation segment with all visible ductal tissue is excised and an end-to-end anastomosis is fashioned.
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in anticipation of surgical repair of other defects, or if the clinical situation could not be defined accurately by less invasive techniques.
Table 2.
Statistical Methods
Operation
Values are shown as mean ⫾ standard deviation. Actuarial survival was performed using a Kaplan-Meier analysis.
Results Early Mortality Although 30-day mortality in this series was zero, there were two deaths before hospital discharge (operative survival, 96%). One infant mentioned previously, who preoperatively had what was believed to be a marginal but acceptable left ventricle, had a reverse subclavian flap repair of his hypoplastic aortic arch with coarctation resection and end-to-end anastomosis. Because of borderline hemodynamics, echocardiogram and cardiac catheterization were performed the next day, which showed a small left ventricle with an end-diastolic pressure of 25 mm Hg. He then was converted over to a first-stage Norwood procedure. His postoperative course was plagued by intermittent bloodstream infections despite good hemodynamics and a satisfactory Norwood palliation by postoperative cardiac catheterization. He eventually succumbed to sepsis almost 4 months postoperatively without ever leaving the hospital. The other death was due to Candida sepsis 5 weeks postoperatively in a patient who had an arterial switch procedure with VSD closure at the time of repair of his aortic arch and coarctation. He, too, died before hospital discharge.
Restenosis The 44 survivors have been followed a mean of 38 months (range, 1 month to 10.8 years). There have been five recurrent obstructions (defined as a gradient ⱖ 20 mm Hg by arm/leg pressures, echocardiogram, or cardiac catheterization) ranging from 2.6 to 7.2 months postoperatively (mean, 4.9 months). Three were stenoses occurring at the site of end-to-end anastomosis; all three were successfully managed with percutaneous balloon dilatation. There were two recurrent arch obstructions. One was successfully balloon dilated 6 months postoperatively. The other child had a 30 mm Hg gradient across the proximal aortic arch between the innominate artery and left carotid artery at catheterization 1 month postoperatively. This required pericardial patch enlargement using profound hypothermia and circulatory arrest 4 months postoperatively. Interestingly, at operation, a mildly obstructive bar of fibrous tissue was excised from the lumen of the aorta at the most proximal site of the reverse subclavian flap. Presumably, this tissue was caused by inadvertently catching the back wall of the aorta when constructing the most proximal portion of the reverse subclavian flap anastomosis stressing the importance of clear exposure of the angle between the left carotid artery
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Subsequent Operations by Diagnostic Group
I. Isolated coarctation with hypoplastic arch (n ⫽ 9) II. With VSD (n ⫽ 14) Close VSD/deband Repair recurrent arch obstruction III. With other biventricular heart disease (n ⫽ 17) Arterial switch procedure/VSD closure CAVSD repair Aortic valvotomy/VSD closure Mitral ring ⫾ VSD closure Mitral valve replacement ALCA/VSD Other IV. With other univentricular heart disease (n ⫽ 6) Glenn anastomosis/DSK Norwood procedure
Number of Patients With Operations 0 10 9 1 14a 3 2 2 2 1 1 3 3 2b 1
a Does not include the 2 patients who had an arterial switch procedure at b One patient with a subsethe time of their arch/coarctation repair. quent Fontan procedure.
ALCA ⫽ repair of anomalous left coronary artery arising from pulmonary trunk; CAVSD ⫽ complete atrioventricular septal defect; DSK ⫽ modified Damus-Stansel-Kaye procedure; VSD ⫽ ventricular septal defect.
and the hypoplastic transverse aortic arch during this anastomosis. Actuarial freedom from recoarctation in this series was 86% ⫾ 14% after 7 months since there have been no episodes of recoarctation recognized after this time.
Subsequent Operations There have been 29 subsequent operations in 27 children (Table 2). None of the 9 children with isolated coarctation with arch hypoplasia have required further surgical intervention. Of the 14 patients in the group with only an associated VSD, 9 of the 10 with pulmonary artery banding have had the band removed with VSD closure (including 3 with multiple VSDs) 7.4 ⫾ 9.0 months after the original operation (range, 1 to 30 months). One patient still awaits pulmonary artery debanding and VSD closure. Fourteen of the 17 patients in the group with biventricular heart disease have had subsequent operations 7.7 ⫾ 10.8 months (range, 1 to 41 months) after the initial arch/coarctation repair (Table 2). Of the remaining 3 patients, 2 had an arterial switch procedure at the time of the original operation and 1 with congenitally corrected transposition of the great arteries, VSD, and mild pulmonary stenosis is awaiting repair and removal of his pulmonary artery band. Three of the 6 patients in the group with univentricular heart disease have had subsequent operations including the infant who had a first-stage Norwood procedure the
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day after his arch/coarctation repair (Table 2). The other 3 patients are awaiting a bidirectional Glenn anastomosis in preparation for an eventual Fontan procedure.
Late Survival There have been two late deaths 3 and 4 months after arch/coarctation repair, both in patients with severe systemic ventricular hypertrophy. One was in an infant with severe left ventricular outflow tract obstruction due to accessory mitral valve tissue. She suffered a cardiac arrest on induction of anesthesia for mitral valve replacement and could never be weaned from cardiopulmonary bypass postoperatively despite 10 days of support with extracorporeal membrane oxygenation. The other child with unbalanced complete atrioventricular septal defect, hypoplastic left ventricle, and a restrictive ventricular communication died 9 days after a bidirectional Glenn anastomosis and modified Damus-Stansel-Kaye procedure due to clotting of his Glenn anastomosis, probably related to marginally low cardiac output. Overall survival in this entire series of 46 infants was, therefore, 91% on follow-up of 36 ⫾ 35 months (range, 1 month to 10.8 years).
Comment Hypoplasia of the transverse aortic arch is commonly associated with coarctation of the aorta in infancy with incidences ranging from 32% to 81% [9, 10]. Using the definition of hypoplastic arch described by Moulaert [1] or Karl [8] and their colleagues, we identified 46 infants of 162 (28%) neonates undergoing coarctation repair who had hypoplasia of the aortic arch between the left carotid artery and the left subclavian artery. These infants underwent reverse subclavian flap repair of the hypoplastic aortic arch at the time of coarctation repair. There are some who contend that it is unnecessary to repair the hypoplastic arch as it will grow with time [11, 12]. Careful reading of these reports, however, reveals possible flaws in the analysis of the data presented. Siewers and colleagues [11] described 33 of 102 (32%) infants with coarctation with associated arch hypoplasia that was not addressed surgically at the time of coarctation repair. At a mean interval of 39 ⫾ 29 months postoperatively, evaluation of the transverse arch showed good growth. However, only 18 of the original 33 patients underwent reevaluation by imaging (presumably the remainder had no arm/leg pressure gradients). There were 3 early and 12 late deaths, although they state that “there was no evidence that the arch hypoplasia itself in any way contributed to the late deaths.” Another article commonly cited as evidence for growth of the hypoplastic transverse aorta after coarctation repair is by Myers and colleagues [12]. Careful reading of this article reveals that they believe a priori that “tubular hypoplasia of the aortic arch proximal to the left subclavian artery require[s] augmentation . . .; therefore, these patients [were] not included in [that] series.” On the other hand, there is reasonable evidence that the hypoplastic aortic arch should be repaired at the time
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of coarctation repair. Early reports show that the presence of arch hypoplasia is an independent risk factor for early mortality after coarctation repair with all 5 patients with arch hypoplasia in the series by Herrmann and associates [13] and 3 of 4 patients with arch hypoplasia in the series by Baudet and Al-Qudah [14] dying early after coarctation repair. Qu and colleagues [15] reported that of 23 infants younger than 6 months undergoing coarctation repair, 5 of the 6 infants with arch hypoplasia (defined as distal arch outer diameter ⬍ 3.9 mm) required arch augmentation. Our own experience is in agreement with these findings. During the same time period of this study, we encountered 8 infants with coarctation who initially underwent only standard subclavian flap repair. They then required augmentation of the aortic arch during this same operation (7 patients) or during a second operation 3 months later (1 patient). Further evidence that the hypoplastic arch does not always grow after coarctation repair is demonstrated by DeLeon and colleagues [16] who reported 6 patients requiring repair of arch hypoplasia late after successful coarctation repair. Even more compelling is the report by Poirier and associates [17] in which 27 patients with previous coarctation repair required subsequent surgical enlargement of a hypoplastic aortic arch. Finally, Machii and Becker [18] examined autopsy specimens of hypoplastic aortic arches and found fewer ␣-actin-positive cells that could indicate a diminished growth potential. Other than these anatomic reasons for repairing the hypoplastic arch at time of coarctation repair, there are convincing physiologic reasons succinctly enumerated by Vouhe´ and colleagues [10]. They argued that any residual arch gradient, even slight, would be poorly tolerated in an infant with preoperatively depressed ventricular function. Second, if there were coexisting left ventricular outflow tract obstruction, an incremental increase in left ventricular work caused by an unrepaired aortic arch would be detrimental. Finally, in patients who undergo concomitant pulmonary artery banding, any unrelieved arch gradient would effectively result in biventricular obstruction. Once one decides it is important to repair the hypoplastic aortic arch at the time of coarctation repair, there are a variety of available surgical techniques. These include the use of a left carotid artery flap [2, 4], resection with extended end-to-end anastomosis [3, 19, 20], repair through a midline sternotomy [8], and use of the left subclavian artery as a free flap [5]. In this series, we have used the left subclavian artery as a viable autologous flap to augment the hypoplastic aortic arch followed by coarctation resection with end-toend anastomosis (Figs 2 to 4). Tiraboschi and colleagues [6] first described the use of a reverse subclavian flap for repair of an unusual coarctation located between the left carotid and left subclavian arteries which was also described later by Hart and Waldhausen [21]. Amato and associates [7] depicted a side-to-side anastomosis between the left carotid and left subclavian arteries augmenting the hypoplastic aortic arch without transecting the subclavian artery distally. The coarctation was re-
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sected with end-to-end anastomosis during the same clamp period. Interestingly, Amato and coworkers [22] later reported a 30% early recoarctation rate with this technique. The modifications we have made with our technique for reverse subclavian flap aortoplasty are important. First, the arch is repaired during a clamp application separate from that used for the coarctation repair (Fig 2). This allows continued perfusion to the lower half of the body through the patent ductus arteriosus. Thus, not only are the spinal cord, kidneys, and viscera protected, but also the amount of cardiac afterload is dramatically reduced as compared to placing a clamp on the proximal aorta between the innominate artery and the left carotid artery at the same time the patent ductus arteriosus is ligated. Second, our technique should minimize the period of left carotid artery clamping as it remains open during the second stage of the repair when the coarctation is resected with end-to-end anastomosis (Fig 4). Although this consideration may be theoretical, there are reports of neurologic complications with extended endto-end repair of coarctation [23], which often is associated with longer carotid occlusion times than described with our technique. Finally, we stress the importance of dividing the left subclavian artery distally. This not only increases the amount of tissue available for arch augmentation, but also allows a tension-free anastomosis (Fig 3) as opposed to the Amato technique with its relatively high recurrence rate [22]. The operative survival in our series of 96% and the intermediate survival of 91% in a fairly heterogeneous group of patients is comparable to or better than survival reported with other techniques for repair of hypoplastic aortic arch with coarctation in infancy [8, 10, 23]. Also our actuarial freedom from restenosis rate of 86% past 7 months up to 10.8 years is respectable compared with other published reports [10, 22, 23]. On reflection, we believe that all three restenoses at the coarctation repair site almost certainly were due to inadequate resection of ductal tissue and thus were technical errors. One of the two arch obstructions was actually not a restenosis but rather uncorrected hypoplasia of the proximal aorta between the innominate artery and the left carotid artery, which of course is not addressed with this surgical technique. Finally, of late there has been interest in simultaneous correction of underlying heart defects at the time of repair of the hypoplastic aortic arch and coarctation arguing that the one-stage approach affords superior results [8]. Thirty-seven of the 46 patients in this series (80%) had additional heart lesions other than the aortic abnormalities. Yet only 2 patients in this series had simultaneous correction of the heart defects (both had an arterial switch procedure through a separate sternotomy). One of these patients accounted for one of the two hospital deaths (Candida sepsis 5 weeks postoperatively). On the other hand, 27 of our patients went on to a staged surgical repair with reasonable results. It could be argued that the only two deaths in these
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patients would not likely have been avoided by a onestage approach. In summary, we have presented a series of 46 infants with coarctation of the aorta and associated arch hypoplasia treated with reverse subclavian flap aortoplasty and resection of the coarctation with end-to-end anastomosis. This technique is technically simple and effective with low operative and intermediate mortality and good freedom from restenosis. Good relief of the arch obstruction allows later correction of heart defects with acceptable results.
References 1. Moulaert AJ, Bruins CC, Oppenheimer-Dekker A. Anomalies of the aortic arch and ventricular septal defects. Circulation 1976;53:1011–5. 2. Allen RG, Maria-Garcia J, Nayek G. Methods of management and results following surgery for coarctation of the aorta in infancy. J Ped Surg 1980;15:953– 60. 3. Zannini L, Lecompte Y, Galli R, et al. Aortic coarctation with hypoplasia of the arch: description of a new surgical technic. G Ital Cardiol 1985;15:1045– 8. 4. Mellgren G, Friberg LG. A new surgical technique for newborn children with coarctation of the aorta and critical hypoplasia of the aortic arch. Scand J Thorac Cardiovasc Surg 1994;28:49–53. 5. Kubota H, Camilleri L, Legault B, et al. Surgical correction of the hypoplastic aortic arch by the subclavian free flap method in the neonate. J Thorac Cardiovasc Surg 1998;116:519–21. 6. Tiraboschi R, Locatelli G, Bianchi T, Parenzan L. Correction of coarctation of the aorta during the first year of life by means of the subclavian flap technique. 8 cases operated on successfully. Surg Italy 1975;5:244–52. 7. Amato JJ, Rheinlander HF, Cleveland RJ. A method of enlarging the distal transverse arch in infants with hypoplasia and coarctation of the aorta. Ann Thorac Surg 1977;23:261–3. 8. Karl TR, Sano S, Brawn W, Mee RBB. Repair of hypoplastic or interrupted aortic arch via sternotomy. J Thorac Cardiovasc Surg 1992;104:688–95. 9. Morrow WR, Huhta JC, Murphy DJ Jr, McNamara DG. Quantitative morphology of the aortic arch in neonatal coarctation. J Am Coll Cardiol 1986;8:616–20. 10. Vouhe´ PR, Trinquet F, Lecompte Y, et al. Aortic coarctation with hypoplastic aortic arch. Results of extended end-to-end aortic arch anastomosis. J Thorac Cardiovasc Surg 1988;96: 557– 63. 11. Siewers RD, Ettedgui J, Pahl E, Tallman T, del Nido PJ. Coarctation and hypoplasia of the aortic arch: will the arch grow? Ann Thorac Surg 1991;52:608–14. 12. Myers JL, McConnell BA, Waldhausen JA. Coarctation of the aorta in infants: does the aortic arch grow after repair? Ann Thorac Surg 1992;54:869–75. 13. Herrmann VM, Laks H, Fagan L, Terschluse D, Willman VL. Repair of aortic coarctation in the first year of life. Ann Thorac Surg 1978;25:57– 63. 14. Baudet E, Al-Qudah A. Late results of the subclavian flap repair of coarctation in infancy. J Cardiovasc Surg 1989;30: 445–9. 15. Qu R, Yokota M, Kitano M, et al. Surgical indication for aortic arch hypoplasia in infants. J Cardiovasc Surg 1990;31: 796 – 800. 16. DeLeon MM, DeLeon SY, Quinones JA, et al. Management of arch hypoplasia after successful coarctation repair. Ann Thorac Surg 1997;63:975– 80. 17. Poirier NC, Van Arsdell GS, Brindle M, et al. Surgical treatment of aortic arch hypoplasia in infants and children with biventricular hearts. Ann Thorac Surg 1999;68: 2293–7. 18. Machii M, Becker AE. Hypoplastic aortic arch morphology
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pertinent to growth after surgical correction of aortic coarctation. Ann Thorac Surg 1997;64:516–20. 19. Lansman S, Shapiro AJ, Schiller MS, et al. Extended aortic arch anastomosis for repair of coarctation in infancy. Circulation 1986;74(Suppl 1):37– 41. 20. Elliott MJ. Coarctation of the aorta with arch hypoplasia: improvements on a new technique. Ann Thorac Surg 1987; 44:321–3. 21. Hart JC, Waldhausen JA. Reversed subclavian flap angio-
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plasty for arch coarctation of the aorta. Ann Thorac Surg 1983;36:715–7. 22. Amato JJ, Galdieri RJ, Cotroneo JV. Role of extended aortoplasty related to the definition of coarctation of the aorta. Ann Thorac Surg 1991;52:615–20. 23. van Heurn LWE, Wong CM, Spiegelhalter DJ, et al. Surgical treatment of aortic coarctation in infants younger than three months: 1985 to 1990. J Thorac Cardiovasc Surg 1994;107: 74– 86.
DISCUSSION DR MARSHALL L. JACOBS (Philadelphia, PA): Doctor Kanter, I am interested in the group with single ventricles and arch hypoplasia, a group where there is always a question or suspicion of systemic ventricular outflow tract obstruction. With the superb results that you have had at your institution with the Norwood operation, how did you differentiate these patients to manage them by arch augmentation and pulmonary artery banding? DR KANTER: Certainly if they had a hypoplastic ascending aorta, then we would use the Norwood technique. The key point was the measurement of the arch between the innominate artery and the carotid artery. If that was less than 60% of the ascending aorta, then we would go ahead with Norwood palliation rather than this technique. DR CHRISTOPHER J. KNOTT-CRAIG (Oklahoma City, OK): I enjoyed the presentation very much, and I was interested to note the heart catheterization visualizing the aorta in the one patient that you presented. Is this something that you do frequently? And if not, can you give us some idea about when you would encourage your cardiologist to catheterize an infant with coarctation? DR KANTER: No. As I said, this series started in 1988 and it dates back from then. Certainly during the past 8 or 10 years it has been terribly uncommon for us to take these children to the operating room with catheterization. We almost always go by echocardiogram alone. DR JOSEPH J. AMATO (Chicago, IL): Doctor Kanter, I congratulate you and your group on an excellent presentation and the wonderful results that you have achieved. I rise to tell you that I have encountered in my experience with repair of coarctation over 16 methods to repair coarctation of the aorta. This comes from the realization that there is a spectrum of entities that require tailoring the operation to the anatomy that the surgeon finds. Although the reverse subclavian flap for repair of the hypoplastic transverse aorta as you described is a highly effective method, it does sacrifice the function of the subclavian artery. I would propose that another method of repairing the hypoplastic arch is to use the extended end-to-end anastomosis as Zannini described in 1985 and Elliott further modified in 1987 using a radical extended end-to-end repair, which actually saves the subclavian artery as it lies over the anastomosis. Again, I congratulate you on your presentation. DR CARL L. BACKER (Chicago, IL): I also congratulate you, Kirk, very nice results. I think that this technique is something everyone should have in their armamentarium for that unusual patient that you can run into. This is another “trick” we can have up our sleeves. I rise mostly to remind and defend the technique of resection with extended end-to-end anastomosis. We presented our results with that that technique at this meeting 2 years ago. For the patient with a hypoplastic arch, much like you showed, I think
that that technique is useful. It is interesting that if you look at the series from Great Ormond Street (London) and Marie Lannelongue (Paris) (Leipzig, Germany), and then the series that Joe mentioned from Italy, there is probably over a thousand neonates from Europe that have been treated with the resection and extended end-to-end anastomosis, of whom probably 30 to 40% have a hypoplastic arch with really excellent results. When I reviewed that for our manuscript, the recurrence rate was about 5% to 10% with a similar low mortality to yours. And I think that in my mind this is becoming, at least at our institution, the procedure of choice. And it is a successful operation for the patient with a hypoplastic arch. I would also remind everyone that when you take the subclavian artery, although the risk is small, there is a risk of hand ischemia. And I was recently shown a case where the surgeon had required amputation of the arm following a subclavian flap. The other thing is that some of these patients— DR JACOBS: The surgeon or the patient? DR BACKER: Both! I remember when we did subclavian flaps routinely, a lot of times the baby’s arm would be quite cool and pale after this surgery, and I would be a little nervous, as a young attending. I wonder if you have seen any problems with hands being cool after this operation? Again, great results and I congratulate you on a nice presentation. DR KANTER: We certainly do see that the hands early on are cool and can sometimes be congested, but we have not had any difficulties with using the subclavian. I am not proposing that this method is to supplant the extended resection with end-to-end anastomosis, but an alternative to it. I don’t want this audience to believe that technique is not without its problems as well. In one large series there was a definite but small incidence of neurologic problems associated with it. The clamp times of the left carotid are clearly longer than with the technique that I have shown here. Although this difference may not be statistically different, all the reported series had longer clamp times than we found. Finally, if there is a technical error in that very proximal, most difficult part of the anastomosis, underneath the proximal aortic arch, then you have converted the patient to a much more difficult problem of proximal arch stenosis, which has to be dealt with from the front on bypass. DR KOZO ISHINO (Okayama, Japan): In terms of ischemic time during arch repair through median sternotomy, we perfuse the innominate artery or subclavian artery during arch repair, placing a cross-clamp between the innominate artery and left carotid artery, so that we can perform the arch repair with heart beating and brain perfusion as well. We have never encountered any neurological problem even in patients with hypoplastic aortic arch.