Modified Norwood/Sano Stage I Palliation for Hypoplastic Left Heart Syndrome without Circulatory Arrest
We present to you a stage-I palliation of hypoplastic left
heart syndrome (HLHS) via a modified Norwood/Sano procedure in a 3.9 kg, 6-day
old neonate with aortic and mitral valves atresia. The neonate had unrestricted
atrial septum and was placed on prostaglandin infusion after birth to maintain
ductal patency.
Our preference is to modify the Sano conduit prior to sternotomy by suturing
the end of a 5-mm ringed Gore-Tex graft to a 7-mm aortic/pulmonary homograft
valve. We believe this minimizes, if not eliminates any additional volume
overload as a result of free pulmonary regurgitation compared to the typical
non-valved Sano conduits.
Cardiopulmonary bypass was maintained via dual arterial (3.5-mm Gore-Tex graft
to the innominate artery and descending aortic cannulation), and single right
atrial cannulation.
On the beating heart, the ductus arteriosus is doubly ligated and divided.
Atrial septectomy is then performed, followed by constructing the distal Sano
anastomosis to the pulmonary artery bifurcation using the valved segment of the
Sano conduit. The proximal Sano was completed as well using the ringed Gore-tex
segment. Arch vessels are then controlled, a side biting clamp is applied on
the proximal descending aorta. On beating heart, the coarctation segment is
resected and the decsending aortic-to- distal arch anastomosis is constructed
using a running 7/0 prolene suture along the back wall. The arch is opened all
the way to the distal ascendign aorta. Once the distal ascending aorta is
reached, cross clamp was applied and cardioplegia is administered. This is
performed at 34 degrees Celsius with both the head and the body perfused.
Modified Damus-Kaye-Stansel (DKS) aortopulmonary anastomosis is then created. A
decellularized pulmonary homograft patch is then used in a Norw ood type
fashion to augment the aortic anastomosis, arch, ascending aorta and the DKS
anteriorly. We trim the patch as we go thus creating an adequate size neoaorta.
This isfollowed by de-airing and removal of clamps.
The Sano conduit is then completed by sewing the valved homograft segment to
the ringed Gore-Tex segment. The patient is weaned off cardiopulmonary bypass
without diffculty.
Postbypass transesophageal echocardiography confirmed the patency of the aortic
arch and the unobstructed flow in the Sano conduit with good ventricular
function. The patient is decannulated.
We performed intraoperative fluorescent angiography using indocyanine green (ICG)
which confirmed good myocardial perfusion and good visualization of epicardial
coronary arteries.
The patient tolerated the procedure well and the chest was closed in a delayed
fashion 2 days later. He was extubated on the 9th postoperative day with excellent
hemodynamics.
References
1. Reinhartz O, Reddy VM, Petrossian E, MacDonald M,
Lamberti JJ, Roth SJ, Wright GE, Perry SB, Suleman S, Hanley FL. Homograft
valved right ventricle to pulmonary artery conduit as a modification of the
Norwood procedure. Circulation. 2006 Jul 4;114(1 Suppl):I594-9.
2. Said SM, Dearani JA. Norwood valved Sano shunt: Early reward versus late
penalty? J Thorac Cardiovasc Surg. 2018 Apr;155(4):7
3. Mascio CE, Spray TL. Distal Dunk for Right Ventricle to Pulmonary Artery Shunt
in Stage 1 Palliation. Ann Thorac Surg. 2015 Dec;100(6):2381-2
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Emphasis on Direct Cannulation of the Descending Aorta.
Hammel JM. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu. 2019;22:14-20
