I will just briefly describe the diagnosis part and important investigations
Al Habib HF, Jacobs JP, Mavroudis C, Tchervenkov CI, O'Brien SM, Mohammadi S, et al. Contemporary patterns of management of tetralogy of Fallot: data from the Society of Thoracic Surgeons Database. Ann Thorac Surg. Sep 2010;90(3):813-9; discussion 819-20. [Medline].
Why I have ended into medical management while I am asked to discuss surgical mangement? ans: basic rule is first to keep the patient alive then treat his disorderInfants with cyanosis are stabilized by administering prostaglandins (to maintain the ductus in an open state). The use of prostaglandins has significantly decreased the need to perform urgent surgery. Instead of performing systemic-to-pulmonary artery shunts on critically ill cyanotic-hypoxic infants, surgeons now have the luxury of having extra time to assess the patient's anatomy and to perform the primary procedure on an elective basis.
There may be an important coronary artery crossing the infundibulum, precluding infundibulotomy and outflow patch placement. In these cases, a right ventricle-to-pulmonary artery homograft conduit is usually required instead to provide an unobstructed outflow. Because such a fixed conduit will need to be replaced one or more times as the child grows, it may be advantageous to place a palliative shunt and delay definitive repair for 1 year or longer to allow for insertion of the largest possible initial homograft.an anomalous left anterior descending (LAD) coronary artery that crosses the right ventricular (RV) outflow tract (RVOT)
Most popular shunt for any age Can be performed in younger infantsLeft sided aortic arch pts have left sided shuntAdvantages of the modified Blalock-Taussig shunt include: preservation of the subclavian artery, suitability for use on either side, good relief of cyanosis,easier control and closure at time of primary repair, excellent patency rate, and (6) decreased incidence of iatrogenic pulmonary/systemic artery trauma.
Performed in infants older than 3 months because the shunt is often thrombosed in in younger infants with smaller arteries.Right sided shunt is performed in patients with left aortic archAnd vice versa.Subclavian artery with ipsilateral pulmonary artery
Increased pulmonary blood flow Interfere with corrective surgery
Robinson JD, Rathod RH, Brown DW, et al. The evolving role of intraoperative balloon pulmonary valvuloplasty in valve-sparing repair of tetralogy of Fallot. J ThoracCardiovasc Surg. Dec 2011;142(6):1367-73.
36. Kreutzer J, Perry SB, Jonas RA, et al: Tetralogy of Fallot with diminutive pulmonary arteries: Preoperative pulmonary valve dilation and transcatheter rehabilitation of pulmonary arteries. J Am CollCardiol 1996; 27:1741. 37. Boucek MM, Webster HE, Orsmond GS, et al: Balloon pulmonary valvotomy: Palliation for cyanotic heart disease. Am Heart J 1988; 115:318. 38. Qureshi SA, Kirk CR, Lamb RK, et al: Balloon dilatation of the pulmonary valve in the first year of life in patients with tetralogy of Fallot: A preliminary study. Br Heart J 1988; 60:232. 39. Sreeram N, Saleem M, Jackson M, et al: Results of balloon pulmonary valvuloplasty as a palliative procedure in tetralogy of Fallot. J Am CollCardiol 1991; 18:159. 40. Sluysmans T, Neven B, Rubay J, et al: Early balloon dilatation of the pulmonary valve in infants with tetralogy of Fallot: Risks and benefits. Circulation 1995; 91:1506. 41. Heusch A, Tannous A, Krogmann ON, et al: Balloon valvoplasty in infants with tetralogy of Fallot: effects on oxygen saturation and growth of the pulmonary arteries. Cardiol Young 1999; 9:17.
Gustafson RA, Murray GF, Warden HE, Hill RC, Rozar GE Jr. Early primary repair of tetralogy of Fallot.AnnThorac Surg. Mar 1988;45(3):235-41. [Medline].
HOW IT IS DIFFERENT FROM TOF?IT IS BECAUSE OF VARIABLE PULMONARY ARTERY ANATOMY AND PRESENCE OF MAPCAs If there are excessive aortopulmonary collaterals that deliver competing flow, and the arterial oxygen saturation is relatively high, coil embolization of some of these vessels and potentially the patent ductusarteriosus may be undertaken. This is particularly useful for those collaterals that may be relatively inaccessible at surgery.
MaGoon ratio and Nakata index are used to quantitate the degree Pulmonary hypoplasia.These Pulmonary arterial measurements for the calculation are critical to surgical planning. These are measured using echocardiography, Angiography and MRIMaGoon ratio1. This is sum of diameters of immediately prebranching left and right pulmonary arteries to descending aorta just above level of diaphragm2. MaGoon ratio is measured by echocardiography, angiography and MRI3. Normal value more than 2 to 2.54. TOF survivor with Pulmonary artesia have MaGoon ratio more than 15. Good Fontan candidate should have MaGoon ratio more than 1.8Nakata index1. Nakata index is Cross sectional area of left and right pulmonary artery in mm2divided by total body surface area (BSA)2. Measured in AP view in cath lab and by MRI3. Left and right pulmonary arteries are measured just before first lobar branching.4. Cross sectional area is measured by ( π X 2/diameter x magnification coefficient expressed for body surface area)5. Normal Nakata value is 330 +/- 30 mm2/BSA6. TOF with PS should have value more than 100 mm2/BSA for survival7. Good Fontan Candidate should have index more than 250 mm2/BSA8. FMorRastelli surgery Nakata index more than 200 mm2/BSA (if less than 200 mm2/BSA than shunt is done instead of Rastelli)