Ann Thorac Surg 2008;85:669-671. doi:10.1016/j.athoracsur.2007.04.060
© 2008 The Society of Thoracic Surgeons
How To Do It
Extracardiac Fontan With Direct Cavopulmonary Connections
Roxane McKay, MD*,
Joseph A. Dearani, MD
Division of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota
Accepted for publication April 13, 2007.
* Address correspondence to Dr McKay, Division of Cardiovascular Surgery, LeBonheur Children’s Medical Center, 50 North Dunlap, Suite 2598, Memphis, TN 38103 (Email: rmck07{at}yahoo.com).
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Abstract
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In order to optimize the Fontan circulation, a technique for direct superior and inferior cavopulmonary connections was devised. Such pathways retain growth potential, obviate suture lines within the right atrium, and avoid prosthetic implants. They thus enable definitive, single-stage ventricular unloading, regardless of patient size or great artery position.
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Introduction
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Experimental and clinical experience suggest extracardiac Fontan circulations may be superior total cavopulmonary connections, but prosthetic conduits within the venous circulation are not ideal, and early occlusion is reported [1]. The following procedure achieved satisfactory direct, total cavopulmonary connections in 21 patients operated personally by the authors since 1995 in Canada, Egypt, Poland, and Qatar. Ages of the patients ranged from 10 months to 13 years (median 5 years), and weights ranged from 6.7 kg to 35 kg (median, 17 kg). The inferior caval vein (IVC) was contralateral to the pulmonary trunk (main pulmonary artery [MPA]) in 14 cases, ipsilateral in 5, and interrupted in 2. Sixteen patients had prior palliation, and 15 required additional procedures at the time of the Fontan operation.
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Technique
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After sternotomy, anterior aspects of the caval veins and MPA were marked, systemic-pulmonary shunts were controlled, and branch pulmonary arteries were dissected as distally as hemodynamic stability permitted. Bypass was then established with venous drainage through right-angle cannulas in the superior caval vein and IVC at its junction with the atrium. Direct cavopulmonary connections were constructed as illustrated in Figure 1. With interrupted IVC, the atrial cuff connected hepatic veins to the MPA. When fenestration was required, either an isolated superior caval vein was left draining to the atrium, or using partial occlusion clamps, a tube graft was interposed between the IVC cannulation site and lateral wall of the atrium during post-bypass ultrafiltration.
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Fig 1. (A) The arterial duct was divided and the left pulmonary artery was mobilized into lobar branches. In the beating, nonejecting heart, the pulmonary trunk (MPA) was divided exactly at the sinutubular junction and its cardiac end was closed. The superior caval vein (SVC) was divided above the sinus node and the cardiac end was closed, taking care to exclude air. Upward SVC retraction facilitated complete dissection of the right pulmonary artery and also into its lobar branches. (B) Downward diaphragm displacement allowed careful incision of pericardial attachments to the inferior caval vein (IVC) and hepatic veins, increasing their intrapericardial length by several centimeters. Continuing this dissection along the right pericardial reflection allowed the pulmonary veins (PV) to fall away from the atrium and increased space for the pathway. The mobilized MPA would be then brought to the side of the inferior caval vein, confirming that direct connection was possible. (C) After cross clamping the aorta, the inferior caval vein detachment started anteriorly with a small, transverse incision, leaving as much atrial tissue attached as possible. Inside the atrium, this incision was extended circumferentially, below the orifices of the inferior pulmonary veins and coronary sinus (CS). The CS cut-back prevented obstruction by subsequent atrial closure. Septal remnants were resected and any intracardiac procedures were performed. Atrial closure parallel to the inferior pulmonary veins optimized space for the inferior caval vein pathway. As this suture line became inaccessible, hemostasis was imperative. (ASD = atrial septal defect.) (D) After removing the air and after aortic unclamping, the atrial cuff was connected end-to-end to the MPA with a fine running absorbable suture (ie, 6-0 or 7-0) interrupted at multiple sites or continuously locked to avoid pursestring narrowing. Because this cuff greatly exceeded the MPA diameter, the anastomosis was often continued along the rightward MPA and (if needed) onto the undersurface of the right pulmonary artery. Finally, the SVC was positioned wherever it was needed on the upper surface of the pulmonary arteries to repair sites of narrowing or previous shunts. Three maneuvers, singly or in combination, resolved inevitable branch pulmonary arterial redundancy: (1) extensive mobilization that permitted lateral displacement, (2) upward incorporation into the SVC connection, or (3) downward displacement into the atrial anastomosis. Alignment of the markers placed before bypass prevented twisting of the vessels.
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Comment
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Our method differs from those previously reported in MPA division at the sinutubular junction rather than its "base" [2] and avoidance of circulatory arrest [3]. Sinus tissue is too delicate for reliable suturing, while a generous atrial cuff permits IVC cannulation comfortably below the anastomosis. This also facilitates connection of contralateral IVCs to the MPA, even without juxtaposed atrial appendages [3].
Previous MPA banding or bidirectional Glenn constitute relative contraindications to this technique, although this series includes such patients, as well as one with simultaneous Damus-Kaye-Stansel anastomosis. Direct connections have not been possible with an absent MPA or a short, posterior MPA contralateral to the IVC. Whereas, in theory, atrial incisions could predispose to arrhythmias, neither these nor pathway stenosis, protein-losing enteropathy, or thromboembolic events occurred during follow-up of 19 early survivors for a mean of 6.5 years (range, 1.8 to 9.5 years). Actuarial survival was 90 ± 7% at 8 years. Direct cavopulmonary connections thus achieved robust and durable pathways without foreign material (Fig 2) and facilitated a single-stage extracardiac Fontan procedure in small patients.
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Fig 2. (A) Representative imaging of pathways by angiography and (B) echocardiography at 6 months and 6 years, respectively, after complete extracardiac Fontan operation at 9.8 kg. (IVC = inferior caval vein; RA = right atrium; RSVC = right superior caval vein.)
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References
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- Kammeraad JAE, Sreeram N. Acute thrombosis of an extracardiac Fontan conduit Heart 2004;90:76.[Free Full Text]
- Van Son JAM, Reddy M, Hanley FL. Extracardiac modification of the Fontan operation without use of prosthetic material J Thorac Cardiovasc Surg 1995;110:1766-1768.[Free Full Text]
- Carotti AI, Iorio FS, Amodeo A, Giamberti A, et al. Total cavopulmonary direct anastomosis: a logical approach in selected patients Ann Thorac Surg 1993;56:963-964.[Abstract/Free Full Text]
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Abstract
Introduction
