Ann Thorac Surg 2007;83:1886-1888
© 2007 The Society of Thoracic Surgeons
Case Reports
Reverse Blalock-Taussig Shunt Facilitates the Growth of the Ascending Aorta After Hybrid Palliation
Tae-Jin Yun, MD, PhDa,*,
Won-Chul Cho, MDa,
Sung-Ho Jung, MDa,
Dong-Man Seo, MDa,
Hyun-Woo Goo, MDc,
Young-Hwue Kim, MDb
a Division of Pediatric Cardiac Surgery, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea
b Division of Pediatric Cardiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea
c Department of Radiology, Asan Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea
Accepted for publication November 20, 2006.
* Address correspondence to Dr Yun, Division of Pediatric Cardiac Surgery, Asan Medical Center, 388-1 Poongnap-Dong, Songpa-Ku, Seoul, 138-736 Republic of Korea (Email: tjyun{at}amc.seoul.kr).
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Abstract
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A 13-day-old baby girl with tricuspid atresia (IIc), who was prematurely born at 32 weeks and 5 days of gestation and weighed 2.2 kg, underwent bilateral pulmonary artery banding, ductal stenting, and reverse Blalock-Taussig shunt. Cardiac computerized tomography at 4 months postoperatively showed that the ascending aorta outgrew the somatic growth, presumably thanks to the forward flow through the reverse Blalock-Taussig shunt. At 6 months postoperatively, the patient underwent a successful second-stage operation.
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Introduction
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Hybrid palliation (ie, bilateral pulmonary artery banding and ductal stenting), which was originally developed for hypoplastic left heart syndrome (HLHS), can be applied to patients with a functional single ventricle and restrictive systemic outflow tract, such as tricuspid atresia with transposition of the great arteries. However this new surgical strategy does not integrate the ascending aorta into the neoaortic system, leaving a small ascending aorta until the time of the second-stage operation, which may be one of the pitfalls of this technique, especially when the blood flow to the ascending aorta is expected to be compromised by the restrictive subaortic area and arch obstruction.
A 13-day-old baby girl with a functional single ventricle underwent hybrid palliation. She had been prematurely born at 32 weeks and 5 days of gestation and weighed 2.2 kg at the time of the procedure. Her diagnosis was tricuspid atresia, d-transposition of the great arteries with a small ascending aorta arising from the right anterior rudimentary right ventricle, restrictive ventricular septal defect (VSD), severe coarctation of aorta, and ductus dependent systemic circulation (Fig 1A). The diameter of the VSD was 3.9 mm, which was only 78% of the size of the hypoplastic aortic valve annulus (5.0 mm; z-score, –4.0).
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Fig 1. (A) Cardiac computerized tomographic scan shows the restrictive ventricular septal defect (VSD), small ascending aorta, and severe isthmic hypoplasia. (B) Hybrid palliation, consisting of bilateral pulmonary artery banding, ductal stenting, and reverse Blalock-Taussig shunt is depicted. (Asc.Ao = asceding aorta; CoA = coarctation of the aorta.)
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On 1 day prior to the procedure, the patient began to show abdominal distention and a blood-tinged stool. Because the Norwood type procedure was deemed too risky, given her low body weight, prematurity, and suspected necrotizing enterocolitis, we elected to perform hybrid palliation (Fig 1B). She was brought to the operating room and underwent bilateral pulmonary artery banding using 2 mm-wide opened rings off a 3.5-mm polytetrafluoroethylene (PTFE) tube graft (Gore-Tex tube graft [W.L. Gore & Assoc, Inc, Flagstaff, AZ]) and ductal stenting using a 15- mm long balloon expandable Genesis stent (Cordis [Jonhson & Johnson, Warren, NJ]). The stent was balloon dilated (10 atmospheres), with a final length and diameter of 13 mm and 7 mm, respectively. A reverse Blalock-Taussig shunt (Rev-BTS) was then placed from the main pulmonary artery to the innominate artery using a 3.5-mm polytetrafluoroethylene tube graft.
After the procedure the patient showed abdominal distention and chylopericardium. However, she slowly recovered and was transferred to the general ward on postoperative day 26. She was discharged home on postoperative day 33.
Cardiac computerized tomography at 4 months postoperatively showed that the ascending aorta outgrew the somatic growth, presumably thanks to the forward flow through the Rev-BTS. It was also shown that the VSD, which already had been preoperatively restrictive, became more restrictive as time passed (Table 1).
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Table 1 Changes in the Dimensions of the Cardiac Structures on Preoperative and Postoperative Cardiac Computerized Tomography
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At 6 months postoperatively the patient underwent a second-stage operation consisting of: (1) takedown of previous hybrid palliation, (2) extensive arch reconstruction using pulmonary homograft and pulmonary artery to ascending aorta anastomosis, (3) wide atrial septectomy, (4) bilateral pulmonary artery angioplasty, and (5) a bidirectional cavopulmonary shunt. It was found at the second-stage operation that the Rev-BTS was still patent and the aortic isthmus had been obstructed by the ductal stent. The postoperative course was uneventful, and she was discharged home on postoperative day 19. She has been followed-up for 5 months since the second-stage operation, almost catching up with the developmental scales of her peers.
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Comment
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Hybrid palliation for HLHS has been performed more frequently in the last few years [1–3], and the indications of this new surgical strategy have been extended from selective patients with high risks [2] to randomized trials along with a conventional or modified Norwood procedure in several cardiac programs [3]. However, a number of controversies as to this strategy still continue, such as the application of the procedure to anomalies other than HLHS (ie, functional single ventricle with systemic outflow obstruction), selection of ductal stents (ie, self-expandable vs balloon-expandable stents), and indication of the placement of Rev-BTS [4]. A Rev-BTS is generally indicated for HLHS with aortic atresia when the retrograde arch flow is expected to be compromised by the ductal stent occluding the aortic isthmus. In this case, we elected to place a Rev-BTS, even if the aortic valve was not atretic, because interventricular communication (or VSD) was expected to get more restrictive [5], which would have compromised antegrade ascending aortic flow. Four months after the procedure it was noted that the ascending aorta outgrew the somatic growth. Because the indexed VSD size became smaller (less antegrade flow) and retrograde arch flow got obstructed by ductal stenting (no retrograde flow) as time passed, the outgrowth of the ascending aorta must have been induced largely by the forward flow through the Rev-BTS. Given the fact that the size of the ascending aorta is one of the major risk factors jeopardizing the inter-stage outcome after the Norwood operation [6], the outgrowth of the ascending aorta can be regarded as an additional benefit of Rev-BTS. With respect to the sequence of the procedures, we advocate a band-stent-Rev-BTS strategy. We believe that pulmonary artery banding should be performed prior to Rev-BTS, because there may be a diastolic run-off from the ascending aorta to the pulmonary artery through the shunt in the absence of pulmonary blood flow restriction by pulmonary artery banding. We also prefer to perform ductal stenting prior to placing Rev-BTS for technical feasibility. This strategy, of course, stipulates that there be adequate antegrade flow to the ascending aorta, which is not the case in patients with aortic atresia.
From our experience, we would suggest more aggressive use of Rev-BTS on hybrid palliation for HLHS or for a functional single ventricle with systemic outflow obstruction, because (1) it guarantees the ascending aortic blood flow after ductal stenting, and (2) it facilitates the outgrowth of the ascending aorta, which may be beneficial for inter-stage survival as well as a successful second-stage operation.
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References
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- Akintuerk H, Michel-Behnke I, Valeske K, et al. Stenting of the arterial duct and banding of the pulmonary arteries: basis for combined Norwood stage I and II repair in hypoplastic left heart Circulation 2002;105:1099-1103.[Abstract/Free Full Text]
- Lim DS, Peeler BB, Matherne GP, Kron IL, Gutgesell HP. Risk-stratified approach to hybrid transcatheter-surgical palliation of hypoplastic left heart syndrome Pediatr Cardiol 2006;27:91-95.[Medline]
- Bacha EA, Daves S, Hardin J, et al. Single-ventricle palliation for high-risk neonates: the emergence of an alternative hybrid stage I strategy J Thorac Cardiovasc Surg 2006;131:163-171.[Abstract/Free Full Text]
- Caldarone CA, Benson LN, Holtby H, Van Arsdell GS. Main pulmonary artery to innominate artery shunt during hybrid palliation of hypoplastic left heart syndrome J Thorac Cardiovasc Surg 2005;130:e1-e2.[Free Full Text]
- Matitiau A, Geva T, Colan SD, et al. Bulboventricular foramen size in infants with double-inlet left ventricle or tricuspid atresia with transposed great arteries: influence on initial palliative operation and rate of growth J Am Coll Cardiol 1992;19:142-148.[Abstract]
- Tweddell JS, Hoffman GM, Mussatto KA, et al. Improved survival of patients undergoing palliation of hypoplastic left heart syndrome: lessons learned from 115 consecutive patients Circulation 2002;106(Suppl I)I-82–9.
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Abstract
Introduction
