Download The Norwood procedure for hypoplastic left heart syndrome: results

Asian Biomedicine Vol. 3 No. 5 October 2009; 567-570
Brief communication (Original)
The Norwood procedure for hypoplastic left heart
syndrome: results of the King Chulalongkorn Memorial
Hospital
Vichai Benjacholamasa, Apichai Khongphatthanayothinb, Pornthep Lertsapcharoenb
a
Cardiothoracic Unit, Department of Surgery, bCardiac Unit, Department of Pediatrics, King
Chulalongkorn Memorial Hospital and Faculty of Medicine, Chulalonngkorn, Bangkok 10330,
Thailand.
Background: The Norwood procedure is often performed to treat hypoplastic left heart syndrome (HLHS).
Only Blalock-Taussig (BT) shunt is used with the Norwood procedure in our institute.
Objective: To analyze the first-stage palliation for HLHS.
Patients and methods: The Norwood procedure with right modified BT shunt was performed in 26 patients
with HLHS between August 1996 and November 2008. The first four patients were performed using only
autologous great vessel tissue (group 1), and the other 22 patients were operated with the Norwood procedure
using a homograft for arch reconstruction (group 2).
Results: The hospital mortality was 50.0 % in group 1 and 18.2% in group 2. The overall hospital mortality was
23.1%. Four out of twenty survivors (20%) had the modified Fontan procedure.
Conclusion: Only a limited number of pediatric cardiac centers offered surgical treatment of the hypoplastic left
heart syndrome. The survival rate in our study was in acceptable range despite the limited resource.
Keywords: Blalock-Taussig shunt, hypoplastic left heart syndrome, Norwood procedure.
The first successful use of the Norwood
procedure was reported by Norwood et al [1, 2]. Since
then, this surgery procedure is most often performed
to treat hypoplastic left heart syndrome (HLHS).
HLHS is certain types of mitral atresia, which is
a lethal condition. The current surgical strategy for
HLHS has evolved into a three-stage palliative
approach. The first-stage Norwood procedure is
performed in the neonatal period. In general, early
survival after the Norwood procedure falls in the range
between 70-80% [3, 4]. Many institutes have reported
increasing survival after using a right ventricular
to pulmonary artery (RV-PA) conduit (Sano shunt)
[5-7], instead of Blalock-Taussig (BT) shunt.
However, according to our experience, we still use
only BT shunt with the Norwood procedure.
Correspondence to: Associated Professor Vichai Benjacholamas,
MD, Chief of Cardiothoracic Unit, Department of Surgery,
Chulalongkorn Hospital, Rama IV Rd, Pratumwan, Bangkok
10330, Thailand. E-mail: [email protected]
In this study, we analyzed intermediate results of
the treatment of HLHS with the Norwood procedure
and BT shunt at the King Chulalongkorn Memorial
Hospital since 1996.
Patients and methods
Patients
Twenty-six patients with HLHS underwent a
Norwood procedure at the King Chulalongkorn
Memorial Hospital between August 1996 and
November 2008. Patients were unselected. The
majority had a normal aortic arch (n=21, 80.8%) and
the remaining five patients had varying degrees of
aortic arch obstruction (Table 1). The median
diameter of the ascending aorta was 2.5 mm (range,
2-7 mm). The Norwood procedure was performed at
a median age of 11 days (range, 3-75 days). The
median weight at operation was 2,850 gm (range 2,0004,200 gm).
V. Benjacholamas, et al.
568
Table 1. Number of patients with hypoplastic left heart syndrome (HLHS) without aortic arch
destruction.
HLHS without aortic arch obstruction
Number of patients
21 (80.8%)
Various degree of aortic arch obstruction
Interrupted aortic arch (type B )
Hypoplasia aortic arch
Hypoplasia aortic arch with tricuspid regurgitation
Coarctation of aorta
Operation technique and perfusion protocol
All operations were performed under deep
hypothermic cardiopulmonary bypass (rectal
temperature at 18 ο C) with circulatory arrest.
Myocardial protection was provided with a single dose
of cold crystalloid cardioplegia (30ml/kg body weight)
administered from a side port of the arterial cannula
after temporarily occluded arch vessels by tourniquets
and by clamping of the descending aorta. The median
duration of cardiopulmonary bypass (CBP) and deep
hypothermic circulatory arrest (DHCA) time were
96 minutes (range: 51-163 minutes) and 66 minutes
(range: 51-97 minutes), respectively. The median
period of cardiopulmonary support (the cumulative
duration of CBP and DHCA) was 159 minutes (range:
125-216 minutes).
The main pulmonary artery was divided at the
level of bifurcation and the distal pulmonary artery
was enlarged with a piece of pericardial patch in
patients who used autologous tissue for arch
reconstruction and with homograft patch in patients
whose arch reconstruction was done with homograft.
An atrial septectomy was performed during circulatory
arrest through the venous cannulation site (right atrial
appendage).
The arch was reconstructed using one of the two
techniques. The first four patients were operated on
by the original technique using only autologous great
vessel tissue [8]. All of the remainders were
reconstructed by homograft patch since September
1999 (3 aortic homografts, 19 pulmonic homografts).
The entire isthmic part of the aorta was removed with
adjacent ductal tissue in all patients.
Pulmonary blood flow was established with a
right modified Blalock-Taussig shunt (RMBTS).
5 (19.2%)
1
1
1
2
The RMBTS was formed by anastomosing a
polytetrafluoroethylene (PTFE) tube graft between the
innominate artery and the upper border of the right
pulmonary artery. A PTFE 4 mm-graft was used in
patients whose weight was more than 3.5 kg, and a
3.5 mm-graft was used in patients whose weight was
less than 3.5 kg.
Postoperative management
Dopamine at 5-10 μg/kg/min doses was used as
standard inotropic agent. Sedation was continued
for 12-24 hours postoperatively according to the
hemodynamic condition.
Late management
Elective cardiac catheterization was performed
at four months after the first stage of palliation. The
second stage bidirectional Glenn (BDG) procedure
was performed five-ten months after the first stage
operation. Operation was performed through median
sternotomy under cardiopulmonary bypass with
beating heart, except in some patients who had
interatrial restriction and needed atrial septectomy.
Statistic analysis
This was a retrospective study based on the review
of hospital records and operative notes. Data were
expressed as median (range) and percentage.
Results
Outcomes for all patients are summarized in Fig. 1.
Vol. 3 No. 5
October 2009
The Norwood procedure for hypoplastic left syndrom
569
26 patients with Norwood
20 survivors 6 HD 5 LD 5 not suitable
for BDG 2 waiting
for BDG
5 BDG 3 loss F/U
5 BTS 2 waiting
for Fontan 2 LD 2 F/U 1 Fontan 3 Fontan HD = Hospital death, LD = late death
Fig. 1 Summary of outcomes for all patients.
Early mortality and morbidity
Six patients (23.1%) died during the hospitalization
for the Norwood procedure. Half of them expired in
the operating room. The patients were divided into
two groups by the technique of arch reconstruction
with or without homograft. Hospital mortality (30-day)
in group 1 (arch reconstruction with autologous tissue)
was 50.0% and group 2 (arch reconstruction with
homograft) was 18.2%, (Table 2).
There were two survivals who developed
coarctation of the aorta and had successful treatment
with balloon dilatation. One patient developed
interatrial restriction and need surgical atrial
septectomy.
Late mortality
There were two late deaths (2/26 patients, 7.7%)
and 12 months after stage 1 palliation.
Long term survival
Of the 20 survivors (77.9%), there were only five
whose pulmonary anatomy and hemodynamic studies
were suitable for the BDG procedure. Three of them
had the modified Fontan procedure and another two
were waiting for the modified Fontan procedure. For
progression of cyanosis and unsuitability for the BDG
procedure, an additional systemic-to-pulmonary shunt
was performed in three survivors. One of them could
receive the modified. Fontan procedure 12 years later
without prior BDG procedure. In summary, four out
of twenty survivors (20%) had the modified Fontan
procedure.
Discussion
Survival in patients where the arch was
reconstructed with homograft was better than when
it was performed with only autologous tissue. Most
of non-surviving patients had cardiomegaly
(demonstrated by chest radiography before operation)
and intra-operation because of thick wall in pulmonary
arteries. Half of non-surviving patients could not be
weaned off cardiopulmonary bypass and expired in
the operating room. Recently, many center replaced
systemic to pulmonary shunt (BTS) with RV-PA
conduit. Many studies demonstrated no difference in
early hemodynamic profile between patients
Table 2. Arch reconstruction techniques used.
Technique
Group 1
Group 2
Autologous great vessel tissue
Homograft patch
Pulmonic homograft
Aortic homograft
Number of patients
Hospital mortality
4
22
19
3
2 (50.0%)
4 (18.2%)
V. Benjacholamas, et al.
570
undergoing a BTS or a RV-PA conduit except for a
higher diastolic blood pressure in the RV-PA conduit
patent. RV-PA conduit did not improve postoperative
survival [9-12]. In our experience, we are still satisfied
with the Norwood procedure with RMBTS. There
was one survivor who had the modified Fontan
procedure without BDG at 12 years old. This patient
had an excellence result. Therefore, some of the
survivors who were not suitable for the BDG
procedure may reach the modified Fontan procedure
in the future.
In conclusion, despite limited resource and a small
number of patients in this study, the outcome of first
stage palliation was in the acceptable range.
The authors have no conflict of interest to report.
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