eMedicine Specialties > Cardiology > Congenital Heart Disease in the Adult
Tetralogy of Fallot: Treatment
Updated: May 1, 2008
Treatment
Medical Therapy
Surgery is the definitive treatment for the cyanotic patient with tetralogy of Fallot (TOF). The primary role of medical therapy is in preparation for surgery. Most infants have adequate saturations and usually undergo elective repair. In infants with acute cyanotic episodes, placing them in a knee-chest position may prove helpful in addition to administering oxygen and intravenous morphine. In severe episodes, intravenous propranolol (Inderal) may be administered, which relaxes the infundibular muscle spasm causing RVOTO. Progressive hypoxemia and the occurrence of cyanotic spells are indications for early surgery. Asymptomatic infants need no special medical treatment.
Surgical Therapy
Factors that increase the risk for early repair of TOF include the following:
- Low birth weight
- Pulmonary artery atresia
- Major associated anomalies
- Multiple previous surgeries
- Absent pulmonary valve syndrome
- Young age
- Old age
- Severe annular hypoplasia
- Small pulmonary arteries
- High peak right ventricular–to–left ventricular pressure ratio
- Multiple VSDs
- Coexisting cardiac anomalies
Palliative procedures
The goals of palliation are to increase pulmonary blood flow independent of ductal patency and to allow pulmonary artery growth and even total correction. Occasionally, an infant with pulmonary atresia or an anomalous LAD coronary artery that crosses the right ventricular outflow tract may not be a surgical candidate for establishing transannular right ventricle–to–pulmonary artery continuity and may require placement of a conduit.
Although artificial conduits can be used, infants with extremely small pulmonary arteries may not tolerate total correction in infancy. These infants may require palliation instead of corrective surgery. Various types of palliative procedures have been developed, but the current procedure of choice is the Blalock-Taussig shunt.
The Potts shunts has been abandoned because of a tendency toward increased pulmonary blood flow and increasing difficulty with takedown at the time of corrective surgery. The Waterston shunt is sometimes used, but it also increases pulmonary artery blood flow. This shunt is more related to pulmonary artery stenosis, which generally requires reconstruction. The Glenn shunt is no longer used because of difficulty in performing a subsequent definitive repair.
Given the problems associated with the aforementioned shunts, placement of the modified Blalock-Taussig shunt (using a Gore-Tex graft between the subclavian artery and pulmonary artery) is the procedure of choice. Advantages of the modified Blalock-Taussig shunt include (1) preservation of the subclavian artery, (2) suitability for use on either side, (3) good relief of cyanosis, (4) easier control and closure at time of primary repair, (5) excellent patency rate, and (6) decreased incidence of iatrogenic pulmonary/systemic artery trauma.
The mortality rate is reportedly less than 1% when placing this shunt. However, the Blalock-Taussig shunt elicits a few complications, including hypoplasia of the arm, digital gangrene, phrenic nerve injury, and pulmonary artery stenosis.
The longevity of palliation after shunt placement varies according to the patient's age at the time of surgery and the type of shunt.
Other forms of palliation that are rarely used today include patching of the right ventricular outflow tract without cardiopulmonary bypass (CPB). This procedure can cause destruction of the pulmonary valve and significant intrapericardial adhesions, and the increased pulmonary artery blood flow can result in congestive heart failure; therefore, its role is limited to treatment of infants with TOF complicated by pulmonary atresia and/or hypoplasia of the pulmonary artery.
In very ill neonates with multiple medical problems, balloon pulmonary valvulotomy has been shown to increase oxygen saturation, thus obviating the need for emergency palliative surgery. However, perforation of the pulmonary artery is a risk with this procedure in neonates.
Corrective surgery
Primary correction is the ideal operation for treatment of TOF and is usually performed under CPB. The aims of the surgery are to close the VSD, to resect the area of infundibular stenosis, and to relieve the RVOTO. Before CPB is initiated, previously placed systemic-to-pulmonary artery shunts are isolated and taken down. Patients then undergo CPB. Associated anomalies, such as ASD or patent foramen ovale, are closed.
Postoperative Details
All infants undergoing open-heart procedures are sent to the pediatric intensive care unit. Hemodynamic parameters must be followed postoperatively. All infants initially remain intubated on a ventilator until cardiac and respiratory status stabilize. To maintain systemic peripheral perfusion, adequate cardiac output and atrial pacing may be required. Patients should be weighed daily to follow volume status. Patients with heart block should have temporary atrioventricular pacing. If intrinsic conduction has not returned in 5-6 days, the patient probably needs a permanent pacemaker.
Results
The outcome of surgical repair is excellent with minimal morbidity and mortality. To date, no difference in operative mortality rates has been noted between transventricular and transatrial approaches.
The occasional patient has an elevated right ventricle–to–left ventricle pressure ratio. This may be due to a number of causes including a residual VSD, pulmonary artery stenosis, and pulmonary artery and valve atresia. These patients tend to do poor and echocardiography (ECHO) is warranted to find the cause. Surgical revision may be required to correct the etiology of the high RV pressures.
With improved techniques, excellent results with early 1-stage repair in infants have been reported. Overall, the mortality rate in most series is 1-5% when the repair is performed primarily or after a systemic-to-pulmonary artery shunt. Similarly, the mortality rate of infants undergoing palliative shunt placement is low (0.5-3%). The survival rate at 20 years is approximately 90-95%.
Improved techniques of myocardial protection with hypothermia, cardioplegia, and even total circulatory arrest are providing excellent results by enabling more precise anatomic repairs in younger infants. Nevertheless, infants receiving complete correction before age 1 year have an increased risk compared with patients older than 1 year.
Revision/reoperation
The literature suggests that approximately 5% of individuals will need a revision/reoperation at some point. Indications for early reoperation include a residual VSD or a residual RVOTO.
Residual VSDs are poorly tolerated in patients with TOF because these individuals cannot tolerate an acutely imposed volume overload. Small, residual VSDs are common after TOF repair and are usually clinically insignificant. A residual VSD with a 2:1 shunt or an RVOTO of greater than 60 mm Hg is an urgent indication for reoperation. Surgery can be performed with low risk and can result in dramatic improvements. Occasionally, pulmonary valve insufficiency may increase and may be associated with right ventricular failure. Recurrent RVOTO may be due to muscular fibrosis or hypertrophy. This problem is generally treated with a pulmonary valve replacement. Porcine valves are preferred over mechanical valves because they have less tendency to thrombose.
Complications
Early postoperative complications include the creation of heart block and residual ventricular septal defects (VSDs). Ventricular arrhythmias are more common and are reportedly the most frequent cause of late postoperative death. Sudden death from ventricular arrhythmias has been reported in 0.5% of individuals within 10 years of repair. The arrhythmias are thought to occur in fewer than 1% of patients having an early operation. As with most heart surgery, the risk of endocarditis is lifelong, but the risk is much less than in a patient with an uncorrected tetralogy of Fallot.
More on Tetralogy of Fallot |
| Overview: Tetralogy of Fallot |
| Workup: Tetralogy of Fallot |
 Treatment: Tetralogy of Fallot |
| Follow-up: Tetralogy of Fallot |
| Multimedia: Tetralogy of Fallot |
| References |
| « Previous Page | Next Page » |
References
Aboulhosn J, Child JS. Management after childhood repair of tetralogy of fallot. Curr Treat Options Cardiovasc Med. Dec 2006;8(6):474-83. [Medline].
Arciniegas E, Farooki ZQ, Hakimi M, Green EW. Results of two-stage surgical treatment of tetralogy of Fallot. J Thorac Cardiovasc Surg. Jun 1980;79(6):876-83. [Medline].
Boechat MI, Ratib O, Williams PL, Gomes AS, Child JS, Allada V. Cardiac MR imaging and MR angiography for assessment of complex tetralogy of Fallot and pulmonary atresia. Radiographics. Nov-Dec 2005;25(6):1535-46. [Medline].
Borow KM, Green LH, Castaneda AR, et al. Left ventricular function after repair of tetralogy of fallot and its relationship to age at surgery. Circulation. Jun 1980;61(6):1150-8. [Medline].
Devore GR, Polanko B. Tomographic ultrasound imaging of the fetal heart: a new technique for identifying normal and abnormal cardiac anatomy. J Ultrasound Med. Dec 2005;24(12):1685-96. [Medline].
Gustafson RA, Murray GF, Warden HE, et al. Early primary repair of tetralogy of Fallot. Ann Thorac Surg. Mar 1988;45(3):235-41. [Medline].
Horer J, Friebe J, Schreiber C. Correction of tetralogy of Fallot and of pulmonary atresia with ventricular septal defect in adults. Ann Thorac Surg. 2005;80:2285-2291. [Medline].
Kirklin JW, Blackstone EH, Kirklin JK, Pacifico AD, Aramendi J, Bargeron LM Jr. Surgical results and protocols in the spectrum of tetralogy of Fallot. Ann Surg. Sep 1983;198(3):251-65. [Medline].
Lee CN, Su YN, Cheng WF, Lin MT, Wang JK, Wu MH. Association of the C677T methylenetetrahydrofolate reductase mutation with congenital heart diseases. Acta Obstet Gynecol Scand. Dec 2005;84(12):1134-40. [Medline].
Lukacs L, Kassai I, Arvay A. Total correction of tetralogy of Fallot in adolescents and adults. Thorac Cardiovasc Surg. Oct 1992;40(5):261-5. [Medline].
Pacifico AD, Kirklin JK, Colvin EV, et al. Transatrial-transpulmonary repair of tetralogy of Fallot. Semin Thorac Cardiovasc Surg. Jan 1990;2(1):76-82. [Medline].
Pacifico AD, Ricchi A, Bargeron LM Jr, et al. Corrective repair of complete atrioventricular canal defects and major associated cardiac anomalies. Ann Thorac Surg. Dec 1988;46(6):645-51. [Medline].
Patel CR, Agamanolis DP, Stewart JW. Prenatal diagnosis of tetralogy of Fallot with obstructed supracardiac totally anomalous pulmonary venous connection. Cardiol Young. Dec 2005;15(6):656-9. [Medline].
Sakamoto T, Nagase Y, Hasegawa H, Shin'oka T, Tomimatsu H, Kurosawa H. One-stage intracardiac repair in combination with external stenting of the trachea and right bronchus for tetralogy of Fallot with an absent pulmonary valve and tracheobronchomalacia. J Thorac Cardiovasc Surg. Dec 2005;130(6):1717-8. [Medline].
Sousa Uva M, Lacour-Gayet F, Komiya T, et al. Surgery for tetralogy of Fallot at less than six months of age. J Thorac Cardiovasc Surg. May 1994;107(5):1291-300. [Medline].
Touati GD, Vouhe PR, Amodeo A, et al. Primary repair of tetralogy of Fallot in infancy. J Thorac Cardiovasc Surg. Mar 1990;99(3):396-402; discussion 402-3. [Medline].
Turley K, Tucker WY, Ebert PA. The changing role of palliative procedures in the treatment of infants with congenital heart disease. J Thorac Cardiovasc Surg. Feb 1980;79(2):194-201. [Medline].
Ungerleider RM. Tetralogy of fallot. In: Sabiston DC, Spencer F, eds. Surgery of the Chest. 6th ed. Philadelphia, Pa: WB Saunders Co; 1995.
Redington AN. Determinants and assessment of pulmonary regurgitation in tetralogy of Fallot: practice and pitfalls. Cardiol Clin. Nov 2006;24(4):631-9, vii. [Medline].
Further Reading
Keywords
tetralogy of Fallot, TOF, Fallot tetrad, pink tetralogy, wooden-shoe heart, boot-shaped heart, coeur en sabot, sabot heart, congenital heart disorders, CHD, congestive heart failure, CHF, cyanosis, cyanotic heart disorder, congenital cardiac defects, ventricular septal defect, VSD, atrial septal defect, ASD, pulmonic valve atresia, pulmonic valve stenosis, infundibular stenosis, dextroposition of the aorta, right ventricular hypertrophy, pulmonary atresia, paradoxical emboli, stroke, pulmonary embolus, subacute bacterial endocarditis, right ventricle outflow tract obstruction, RVOTO, cardiopulmonary bypass, CPB, Blalock-Taussig shunt, pentad of Fallot, cleft lip, cleft palate, hypospadias, pentalogy of Fallot
