Asian Cardiovasc Thorac Ann 2007;15:327-331
© 2007 Asia Publishing EXchange Ltd
Single-Stage Versus Two-Stage Modified Fontan Procedure
Sukasom Attanavanich, MD,
Alisa Limsuwan, MD1,
Suthep Vanichkul, MD1,
Panuwat Lertsithichai, MD,
Montein Ngodngamthaweesuk, MD
Cardiovascular & Thoracic Unit
1 Pediatric Cardiology Unit, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand
For reprint information contact: Sukasom Attanavanich, MD Tel: 66 2 201 1315 Fax: 66 2 201 1316 Email: rasac{at}mucc.mahidol.ac.th, Cardiovascular Thoracic Unit, Division of Surgery, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok 10400, Thailand.
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ABSTRACT
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We compared surgical outcomes of the single-stage and two-stage modified Fontan procedures to clarify clinical superiority. Of 28 children undergoing a modified Fontan procedure from October 1995 to October 2005, 15 had a 1-stage and 13 had a 2-stage operation. In the 2-stage group, pulmonary artery growth was evaluated before and after the first stage. Operative mortality was 26.6% in the 1-stage group and 0% in the 2-stage group. The benefits of a previous bidirectional Glenn shunt were decreased cyanosis and volume overload, but there was no significant difference in pulmonary artery growth reflected in pulmonary artery indices before and after the bidirectional Glenn procedure. Older children underwent a 2-stage modified Fontan procedure and had better outcomes in terms of lower mortality, improved oxygen saturation, decreased volume load, and less deterioration of atrioventricular valve regurgitation.
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INTRODUCTION
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The Fontan operation has become the standard procedure for a wide variety of complex congenital heart diseases, particularly univentricular heart. Some modifications have been introduced. In 1988, de Leval reported the advantages of a lateral tunnel total cavopulmonary connection over an atriopulmonary connection.1 Marcelletti and colleagues2 described a total cavopulmonary connection procedure using an extracardiac conduit from the inferior vena cava to the pulmonary artery (PA). The extracardiac conduit procedure provides superior hemodynamics compared to the intra-atrial lateral tunnel and extracardiac tunnel techniques. The hemodynamic advantages are markedly enhanced by the use of a conduit-to-superior vena cava offset, particularly at the high physiologic flows that occur on exercise.3 We performed the lateral tunnel technique prior to 2000, since then we have employed the extracardiac conduit technique in selected older children with favorable criteria for a 1-stage Fontan procedure, while children less than 3 years old or considered high risk underwent a 2-stage procedure.4 Whether a 2-stage procedure has a more favorable outcome than the 1-stage operation has still to be confirmed. With modifications of the procedures, both a lateral tunnel and an extracardiac conduit have been used in both groups. We reviewed our surgical outcomes of the 1- and 2-stage modified Fontan procedures to clarify clinical superiority.
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PATIENTS AND METHODS
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All 28 patients who underwent a modified Fontan procedure at Ramathibodi Hospital from October 1995 to October 2005 were enrolled in this study. Fifteen patients had a 1-stage operation, and 13 had a 2-stage procedure. We performed both lateral tunnel and extracardiac conduit modified Fontan procedures in both groups; after 2000, we used an extracardiac conduit in all patients. A 1-stage operation was considered in patients with suitable criteria according to the original Fontan guidelines.5 Younger children (<2-years old) with cyanosis were palliated by a modified Blalock-Taussig shunt, while those over 2 years of age underwent a bidirectional Glenn shunt.
The complete modified Fontan procedure using a lateral tunnel was considered for children > 3 years old, while children > 6 years of age had an extracardiac conduit. Medical records, echocardiograms, and preoperative cardiac catheterization records were reviewed. The age range at operation was 4–21 years in the 1-stage group, and 3–11 years in the 2-stage group. Body weights ranged from 11 to 54 kg in the 1-stage group and 13 to 31 kg in the 2-stage group. The characteristics of both groups are summarized in Table 1
. Preoperative hemodynamic variables are shown in Table 2. The PA index and other preoperative hemodynamic variables were not significantly different between the 2 groups. In the 2-stage group, PA growth was analyzed before the bidirectional Glenn procedure and before the final operation (Table 3); however, there was no significant difference in PA indices at these times.
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Table 2. Preoperative Hemodynamic Parameters on Catheterization of Patients Undergoing 1-Stage (n = 15) and 2-Stage (n = 13) Fontan Operations
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Table 3. Demographic and Echocardiography Data Before Bidirectional Glenn Shunt and Before 2nd Stage in 2-Stage Fontan Group (n = 13)
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In the 1-stage modified Fontan group, patients were divided into 2 subgroups. In the first subgroup, 12 patients underwent the lateral tunnel procedure under cardiopulmonary bypass (CPB) and cardioplegic arrest. The superior vena cava was anastomosed to both the superior and inferior surfaces of the PA. A polytetrafluoroethylene intra-atrial baffle was placed via a longitudinal atrial incision to direct blood flow from the inferior vena cava to the superior vena caval orifice, which was connected to the inferior surface of the PA. In the second subgroup, 3 patients underwent an extracardiac conduit modified Fontan procedure under CPB without cardioplegic arrest. The superior vena cava was connected to the superior surface of the PA, and a polytetrafluoroethylene conduit of at least 16 mm in diameter was connected from the inferior vena cava to the inferior surface of the PA. Currently, we fenestrate (diameter, 5 mm) the cavopulmonary channel with the right atrium. In the 2-stage modified Fontan group, the patients underwent a prior bidirectional Glenn anastomosis (Table 3
). The complete modified Fontan procedure using a lateral tunnel was as described above, and during placement of the extracardiac conduit, the heart was arrested only when intracardiac procedures were required. All patients in both groups were given warfarin postoperatively to prevent thromboembolism by maintaining the international normalized ratio at 2.3–2.8.
Data from the 1-stage and 2-stage groups were compared using the unpaired Student’s t test, Fisher’s exact test, or the chi-squared test, as appropriate. Data are presented as mean ± standard deviation. Statistical significance was defined as a p value less than 0.05.
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RESULTS
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The underlying cardiac conditions as well as ventricular morphology were similar in both groups. All children had cardiac catheterization prior to the modified Fontan procedure; hemodynamic parameters were similar in both groups (Table 2). The CPB and aortic cross clamp times were also similar. Only 2 parameters were significantly different between groups: patients who had a 2-stage procedure were fenestrated more often than those in the 1-stage group; and the cavopulmonary anastomosis technique in the 1-stage group was predominately a lateral tunnel technique, whereas an extracardiac conduit procedure was more common in the 2-stage group. A polytetrafluoroethylene graft at least 16 mm in diameter was used for the extracardiac conduit. Pulmonary arterioplasty was performed in 1 patient in each group. In the 2-stage group, a bidirectional Glenn shunt procedure was performed as the initial procedure followed by a complete modified Fontan operation when the child was > 6 years old. The interval between stages was 45 ± 33 months.
There were 4 hospital deaths in the 1-stage group (operative mortality, 26.6%), while no death occurred in the 2-stage group (p < 0.05). All 4 deaths were in patients who had undergone lateral tunnel cavopulmonary connection without fenestration; 2 had central venous pressure > 30 mm Hg, and 2 had pulmonary edema from significant atrioventricular valve regurgitation. There was no significant difference in postoperative pericardial effusion between the groups. One patient in the 2-stage group had a postoperative cerebral complication from air embolism, but recovered completely. There was no difference between groups in the incidence of complications. The surgical outcomes are summarized in Table 4.
All patients have been followed up on a regular basis (median duration, 60 months) by electrocardiography, chest radiography, echocardiography, and blood tests. The incidence of early and late deaths, re-operations, and late complications (protein-losing enteropathy, systemic thromboembolism, and supraventricular arrhythmias) were compared between the 1- and 2-stage groups. There was no late death among our hospital survivors. One patient in the 1-stage group was readmitted because of massive pericardial effusion 3 weeks after discharge.
Five patients in each group developed prolonged pleural effusion that resolved with conservative treatment. One patient in the 1-stage group developed systemic thromboembolism from irregular warfarin treatment. All patients were in New York Heart Association class I or II. None developed supraventricular arrhythmias.
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DISCUSSION
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In 1971, Fontan and Baudet6 described an atriopulmonary anastomosis as definitive palliation for tricuspid atresia. This procedure was subsequently known as Fontan anastomosis, and it has been applied to repair several congenital cardiac malformations. Many reports have shown that the results of the Fontan operation depended on the size of the pulmonary arteries.7–9 Anderson and colleagues5 suggested selection criteria for the Fontan procedure. In 1988, de Leval and colleagues1 proposed total cavopulmonary connection by a lateral tunnel as an alternative to the Fontan-type operation, with hemodynamic advantages and reduced atrial complications. This became the standard technique for repair of a wide variety of complex heart diseases until 1990 when Marcelletti and colleagues2 described total cavopulmonary connection using an extracardiac conduit from the inferior vena cava to the PA. This has beneficial hemodynamic effects on systemic venous flow, while the entire atrium is left at low pressure with minimal atrial sutures. Moreover, this technique can be performed without aortic cross clamping. Currently, it can be performed without cardiopulmonary bypass.10,11 Both the lateral tunnel and extracardiac conduit modifications of the Fontan procedure are the current standards for right heart bypass. While the selection of patients depends on their suitability and limitations of their anatomy, as well as the preference of the individual surgeon, the extracardiac conduit procedure is more suitable for older children who are more likely to receive an adult-sized conduit. We performed the modified Fontan in one stage when a patient met the criteria for a low-risk Fontan, specifically, when the age of the child was at least 4 years for the lateral tunnel, and older than 6 years for the extracardiac conduit; McGoon ratio > 1.8 or PA index > 200, low PA pressure (< 15 mm Hg), and no significant atrioventricular valve regurgitation. We consider the 2-stage procedure for the high-risk group and younger children (< 4 years old).
In our patients undergoing a 2-stage operation, the bidirectional Glenn shunt procedure was performed initially, followed by a complete modified Fontan procedure when the child was > 6 years old. We believe in the advantages of fenestration for adaptation during the initial stage of Fontan circulation, and routinely perform a 5-mm fenestration in all patients at least 7 years old. All our patients have been followed up by a pediatric cardiologist and a cardiac surgeon. It was found that none needed closure of the fenestration, and systemic oxygen saturation was more than 95% in all cases. Three of the 4 deaths in the 1-stage Fontan group were due to elevated central venous pressure, despite preoperative cardiac catheterization demonstrating mean PA pressure < 20 mm Hg. The other death was from pulmonary edema secondary to atrioventricular valve regurgitation. We believe the prior bidirectional Glenn shunt procedure will provide favorable outcomes, particularly reduced cyanosis, preserved myocardial function due to decreased volume overload in the univentricular heart, and avoidance of atrioventricular valve regurgitation. The 1-stage modified Fontan procedure may put patients at higher surgical risk due to poor cardiovascular adaptation.
This study compared the outcomes of 1-stage and 2-stage modified Fontan procedures performed concurrently over the last 10 years at a single institution. The 2-stage group had a lower mortality rate, although there was no difference in complications. The 1-stage modified Fontan remains the procedure of choice for suitable selected patients, but for high-risk groups and younger children, the 2-stage modified Fontan procedure is recommended. Although there was a significant difference between the lateral tunnel and the extracardiac conduit in the 2 groups, the choice depends on the patient’s anatomy and the preference of the surgeon.
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REFERENCES
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- de Leval MR, Kilner P, Gewillig M, Bull C. Total cavopulmonary connection: a logical alternative to atriopulmonary connection for complex Fontan operations. Experimental studies and early clinical experience. J Thorac Cardiovasc Surg 1988;96:682–95.[Abstract]
- Marcelletti C, Corno A, Giannico S, Marino B. Inferior vena cava-pulmonary artery extracardiac conduit. A new form of right heart bypass. J Thorac Cardiovasc Surg 1990;100:228–32.[Abstract]
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- Anderson RH, Macartney FJ, Shinebourne EA, Tynan M. Tricuspid atresia. In: Paediatric Cardiology vol. 2. Edinburgh: Churchill Livingstone, 1987:675–96.
- Fontan F, Baudet E. Surgical repair of tricuspid atresia. Thorax 1971;26:240–8.[Abstract/Free Full Text]
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- Girod DA, Rice MJ, Mair DD, Julsrud PR, Puga FJ, Danielson GK. Relationship of pulmonary artery size to mortality in patients undergoing the Fontan operation. Circulation 1985;72(3 Pt 2):II93–6.[Medline]
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ABSTRACT
INTRODUCTION
