Ann Thorac Surg 2009;88:690-691. doi:10.1016/j.athoracsur.2008.11.071
© 2009 The Society of Thoracic Surgeons
How To Do It
Improved Pulmonary Artery Geometry After a Norwood Procedure by Using a Venaflo II Graft as an RV–MPA Conduit
Chung-Dann Kan, MDa,c,
Hsuan-yin Wu, MDa,
Jieh-Neng Wang, MDb,c,
Jing-Ming Wu, MDb,
Yu-Jen Yang, MD, PhDa,c,*
a Department of Surgery, National Cheng Kung University, Taiwan, Republic of China
b Department of Pediatrics, National Cheng Kung University, Taiwan, Republic of China
c Institute of Clinical Medicine and Cardiovascular Research Center, Medical College, National Cheng Kung University, Taiwan, Republic of China
Accepted for publication November 26, 2008.
* Address correspondence to Dr Yang, Department of Surgery, National Cheng Kung University Hospital, 138 Sheng-Li Rd, Tainan, Taiwan, 704, Republic of China (Email: kcd56{at}mail.ncku.edu.tw).
 |
Abstract
|
|---|
Sano's modification of the right ventricle to main pulmonary artery shunt improves the surgical results of the Norwood procedure for hypoplastic left heart syndrome. Usually the transected distal stump of the main pulmonary artery is reconstructed by direct suturing of a polytetrafluoroethylene tube or suturing on a pericardial bifurcation patch. However, the resulting pulmonary artery geometry significantly affects the outcome of the staged procedure. Herein, we report our surgical strategy to improve the pulmonary artery geometry by using a commercially available Venaflo II graft (Bard, Tempe, AZ) as the right ventricle to main pulmonary artery conduit, to avoid the potential for pulmonary artery stenosis after the Norwood procedure.
|
Introduction
|
|---|
Sano's modification of the right ventricle to main pulmonary artery (RV–MPA) shunt improves the surgical results of the Norwood procedure for hypoplastic left heart syndrome. Usually, the transected distal stump of the MPA is reconstructed by direct suturing of a polytetrafluoroethylene tube, by suturing on a pericardial bifurcation patch, or by using a handmade, cuffed polytetrafluoroethylene tube [1, 2]. However, the resulting pulmonary artery (PA) geometry significantly affects the outcome of the staged procedure. Herein, we report our surgical strategy to improve the PA geometry by using a commercially available Venaflo II graft (Bard, Tempe, AZ) as the RV–MPA conduit, to avoid the potential for pulmonary artery stenosis (PS) after the Norwood procedure.
|
Technique
|
|---|
A 3.2-kg male baby was born with cyanosis. His echocardiography revealed a hypoplastic left ventricle and aortic structure, with the ascending aorta measuring approximately 3 mm. A modified Norwood procedure was scheduled at 7 days of age [3]. After a median sternotomy and thymus removal, the ascending aorta, aortic arch, and its branches (ie, the PA, ductus arteriosus, and the descending aorta) were carefully dissected out. Cardiopulmonary bypass was established by a single arterial perfusion by use of a polytetrafluoroethylene tube anastomosed to the innominate artery, with single atrial drainage. The ductus arteriosus was ligated when cardiopulmonary bypass was started, and the MPA was transected just proximal to the bifurcation site. Anticipating the possibility of PA compression by the neoaorta, potential central PS at the shunt insertion site and the need for subsequent PA plasty [2], we chose a 6-mm Venaflo II graft (Bard), trimmed the preformed cobra-head cuff (Fig 1A), and anastomosed this to the defect in the distal PA (Fig 1B). Under deep hypothermia, with isolated cerebral perfusion and cardioplegia, we divided the ductus arteriosus near the aortic side, and excised as much ductal tissue as possible. The aortic arch was opened inferiorly and the opening extended proximally to the innominate artery and distally to just beyond the ductal insertion. Then we proceeded to make an anastomosis between the proximal MPA and the aortic arch by means of Brawn's modification [4]. During a short period of circulation arrest, the atrial septal defect was enlarged. Cardiopulmonary bypass was then resumed, and all snares and clamps were removed. During rewarming, the RV–MPA conduit was oriented, trimmed, and anastomosed to the RV. After meticulous hemostasis was achieved, the patient was weaned from cardiopulmonary bypass. Sternal wound closure was delayed until 2 days later. Postoperative hemodynamics were relatively stable. Five months later, follow-up angiography revealed a good PA configuration with a PA pressure of 20/14 mm Hg (Fig 2A). He is now being closely followed-up in outpatient clinics and is waiting for a stage II operation.
View larger version (113K):
[in this window]
[in a new window]
|
Fig 1. (A) The cobra-head cuff of the Venaflo II graft (Bard, Tempe, AZ). (B) The anastomosed Venaflo II graft (Bard) was located just below the neoaorta.
|
|
View larger version (48K):
[in this window]
[in a new window]
|
Fig 2. (A) The follow-up angiography revealed a good pulmonary artery (PA) configuration. (B) A coronal view of the neoaorta at the PA level. The reconstructed PA stump with the cobra-head cuff of the graft avoids potential compression effects by the neoaorta. (AsAo = ascending aorta; Neo Ao = neoaorta; PA = pulmonary artery; PDA = patent ductus arteriosus; RV-MPA = right ventricle to main pulmonary artery.)
|
|
|
Comment
|
|---|
The stage I Norwood procedure with Sano's modification for the hypoplastic left heart syndrome has gained popularly in recent years. It consists of aortic arch reconstruction and a RV–MPA shunt. We adapted Brawn's method for arch reconstruction without the use of a homograft or xenopericardium, not only because of the risk of calcification of the homograft or xenopericardium in later years, but also because of the possible bowstring effect on the left pulmonary artery due to the redundant neoaorta. The direct anastomosis between the MPA and the aortic arch did "pull-up" the MPA to the undersurface of the aortic arch, without impinging on the left pulmonary artery [5].
The RV–MPA shunt provides more stable and symmetrical pulmonary flow; however, a very high incidence (up to 66.7%) of post-Norwood central PS and the necessity for PA reconstruction at a later stage have been reported [2]. Such an unfavorable PA geometry would preclude a final, successful Fontan circulation. The mechanisms corresponding to the development of PS include extrinsic compression by the neoaorta, contraction of remnant ductal tissue, and distortion at the site of shunt insertion [2]. We adopted the Venaflo II graft with its preformed cobra-head cuff for the reconstruction of the PA confluence, not only because it fits and enlarges the distal stump, but also because it results in a leftward shift of the MPA orifice, which can avoid potential compression by the neoaorta (Fig 2B). In addition, the one-piece construction of the Venaflo graft simplifies the reconstruction of the PA and reduces the incidence of bleeding that has been reported after the use of composite conduits [3]. In addition, its being carbon-impregnated might decrease platelet adhesion and fibrin deposition on the graft and thus provide improved patency.
In conclusion, when considering the potential for compression of the reconstructed PA by the neoaorta, possible central PS at the shunt insertion site, and avoiding intractable bleeding with the use of a composite conduit in stage I procedures for hypoplastic left heart syndrome with Sano's modification, the Venaflo II graft is an ideal choice for the RV–MPA conduit.
|
References
|
|---|
- Sano S, Ishino K, Kado H, et al. Outcome of right ventricle-to-pulmonary artery shunt in first-stage palliation of hypoplastic left heart syndrome: a multi-institutional study Ann Thorac Surg 2004;78:1951-1957.[Abstract/Free Full Text]
- Nakano T, Fukae K, Sonoda H, et al. Follow-up study of pulmonary artery configuration in hypoplastic left heart syndrome Gen Thorac Cardiovasc Surg 2008;56:54-61.[Medline]
- Sano S, Ishino K, Kawada M, Honjo O. Right ventricle-pulmonary artery shunt in first-stage palliation of hypoplastic left heart syndrome Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2004;7:22-31.[Medline]
- Bu'Lock FA, Stumper O, Jagtap R, et al. Surgery for infants with a hypoplastic systemic ventricle and severe outflow obstruction: early results with a modified Norwood procedure Br Heart J 1995;73:456-461.[Abstract/Free Full Text]
- Fraser Jr CD, Mee RB. Modified Norwood procedure for hypoplastic left heart syndrome Ann Thorac Surg 1995;60(Suppl 6):S546-S549.[Medline]
This article has been cited by other articles:
|
|
|
|
 
K. Januszewska, R. Kozlik-Feldmann, R. Dalla-Pozza, S. Greil, J. Abicht, H. Netz, B. Reichart, and E. Malec
Right ventricle-to-pulmonary artery shunt related complications after Norwood procedure
Eur J Cardiothorac Surg,
September 1, 2011;
40(3):
584 - 590.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
