Total correction of tetralogy of Fallot

Total correction of tetralogy of Fallot

Current Techniques Total correction of tetralogy of Fallot How to deal with the complicated ascending aorta-right pulmonary artery anastomosis Ascend...

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Current Techniques

Total correction of tetralogy of Fallot How to deal with the complicated ascending aorta-right pulmonary artery anastomosis Ascending aorta-right pulmonary artery anastomosis may be complicated by deformity at the anastomotic site leading to discontinuity between pulmonary artery branches. Simple closure of such shunts through the ascending aorta is associated with residual stenosis and pressure gradients. An alternative approach which allows reconstruction of the entire intrapericardial pulmonary arterial system at the initial corrective operation is described. The transection of the ascending aorta facilitates the exposure necessary for this extensive repair. Two illustrative cases are presented.

M. Arisan Ergin, M.D., and Randall B. Griepp, M.D., Brooklyn. N. Y.

In

the treatment of tetralogy of Fallot, total correction is the method of choice in all age groups with suitable anatomy. I. 2 Markedly hypoplastic pulmonary arteries impose a prohibitively high operative risk on patients undergoing total correction in infancy. 3. 4 In these patients the ascending aorta-right pulmonary artery anastomosis has been used successfully for palliation.":" A frequent complication of this anastomosis is stenosis and distortion of the right pulmonary artery. The reported incidence of this complication in patients undergoing total correction varies from 23 to 88 percent. 9-11 The presence of a Waterston anastomosis, especially when it is impeding flow and continuity between the main pulmonary artery and the right pulmonary artery, complicates the definitive repair. The shunt has to be closed and the pulmonary artery has to be reconstructed with elimination of any residual stenosis. This task may

From the Department of Surgery, State University of New York, Downstate Medical Center. Brooklyn. N. Y. Received for publication June 7, 1978. Accepted for publication Nov. 14. 1978. Address for reprints: M. Arisan Ergin, Department of Surgery, Box 40, Downstate Medical Center, 450 Clarkson Ave., Brooklyn, N. Y. 11203.

be technically demanding, and several methods of dealing with this problem have been described. 12. 13 The following two cases illustrate our preferred method of dealing with the stenotic, deformed right pulmonary artery at the time of total correction for tetralogy of Fallot in patients who have had a previous aorta-right pulmonary artery anastomosis.

Case reports CASE I. S. B., a 4 1h-year-old girl, had been examined as an infant in 1973, and the diagnosis of tetralogy of Fallot with pulmonary atresia had been made. She had undergone an ascending aorta-right pulmonary artery shunt with a good clinical result. She was readmitted for elective total correction in March, 1978. Cardiac catheterization revealed an aortic oxygen saturation of 80 percent, a large ventricular septal defect (VSD) with overriding aorta, and infundibular valvular pulmonary stenosis with a small main pulmonary artery (Fig. I). The Waterston anastomosis was open. There were gross distortion and kinking of the right pulmonary artery with shunt flow only to the right lung (Fig. 2). Pulmonary artery pressure was not determined inasmuch as neither the shunt nor the pulmonary artery could be entered. The coronary anatomy was normal. Complete correction was carried out by the technique to be described (see Technique). Pressures (in millimeters of mercury) measured following discontinuation of cardiopulmonary bypass were as follows: right ventricle 50/8, main

0022-5223/79/030469+05$00.50/0 © 1979 The C. V. Mosby Co.

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of age. She was admitted in September, 1977, for the corrective operation. Cardiac catheterization showed typical tetralogy of Fallot anatomy with a large VSD, an overriding aorta, and severe pulmonary stenosis. An atrial septal defect was also present. The ascending aorta-right pulmonary artery shunt was patent but flow was directed only to the right lung. The right pulmonary artery was grossly deformed at the site of the shunt, with kinking and poststenotic dilatation. Total correction was carried out as described (see Technique). Pressures (in millimeters of mercury) measured following discontinuation of cardiopulmonary bypass were as follows: right ventricle 45/10, main pulmonary artery 30/12, distal right pulmonary artery 25/10, left pulmonary artery 30/12, and left ventricle 95/7. Postoperatively, she required inotropic support for 24 hours and was discharged on the twenty-eighth postoperative day. She was placed on a regimen of furosemide for 2 months following operation and continues to take digoxin at 8 months. She is asymptomatic.

Technique Fig. I. Left ventricular angiogram in right anterior oblique projection shows typical tetralogy anatomy. Notice the thickened stenotic pulmonary valve and small main pulmonary artery (Case I).

Fig. 2. Ascending aortic angiogram shows the patent Waterston anastomosis. The distortion and kinking of the right pulmonary artery with shunt flow directed only to the right lung are evident (Case I). pulmonary artery 45/15, distal right pulmonary artery 30/10, left pulmonary artery 35/10, and left ventricle 110110. The patient left the operating room with a small amount of inotropic support, was extubated the following morning, and subsequently had an uncomplicated postoperative course except for an episode of otitis media that responded to antibiotic treatment. She was discharged on the twenty-first postoperative day. She has remained asymptomatic while receiving no medications. CASE 2. C. B., a 2 1/2-year-old girl, had cardiomegaly and congestive heart failure with repeated respiratory infections. A diagnosis of tetralogy of Fallot had been made in infancy and a Waterston anastomosis had been performed at 6 months

The chest is opened through a median sternotomy incision. Prior to standard cannulation for cardiopulmonary bypass, the atria and both ventricles are freed from the pericardial adhesions and an effort is made to preserve an adequate patch of pericardium for pulmonary artery reconstruction. The superior and inferior venae cavae are encircled with tapes as is the ascending aorta distal to the Waterston anastomosis. The anastomosis is dissected free, so that the anatomy is delineated. Heparin is then administered and cannulation is performed. Hyperkalemic arrest and profound topical hyothermia are utilized for myocardial protection, 14 and an aortic cross-clamp is applied. The left atrial appendage is cannulated with a small suction catheter to ensure a dry operative field. After application of caval chokers, a vertical right ventriculotomy, strictly avoiding major coronary branches, is made on the outflow tract. Removing hypertrophic infundibular muscle bundles exposes the VSD. The VSD is closed with a woven Dacron patch by means of interrupted mattress sutures. At this point the ventriculotomy is extended across the atretic or stenotic pulmonary valve into the hypoplastic main pulmonary artery, and the size of the right and left pulmonary arteries is assessed. The ascending aorta is transected, the Waterston anastomosis being left on the right pulmonary artery (Fig. 3, A and B). Transecting the aorta gives excellent exposure to the entire right pulmonary artery and bifurcation of the main pulmonary artery. The incision in the main pulmonary artery is extended over the bifurcation into the right pulmonary artery beyond the Waterston anastomosis and halfway into the left pulmonary artery, so that the entire pulmonary arterial tree inside the pericardium is effectively laid open (Fig. 3, C). A T -shaped pericardial patch is then sewn with a running suture of 5-0 Prolene into the unroofed pulmonary ar-

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Fig. 3. Operative technique. A, Ventricular septal defect is closed through a vertical ventriculotomy. B. Ascending aorta is transected leaving the anastomotic site on the right pulmonary artery. The proposed line of incision in the pulmonary artery is indicated. C, Pulmonary artery is incised in preparation for the enlarging pericardial patch angioplasty. D, Pericardial patch is sutured in place on the right pulmonary artery with continuous suture . The aorta is reanastomosed and vented to re-establish coronary perfusion. E. Procedure completed. Notice the T-shaped pericardial patch extended to the pulmonary anulus and the Dacron patch used for enlargement of the right ventricular outflow tract. tery starting at the right pulmonary artery. When the suture lines reach the main pulmonary artery, the transected aorta is reanastomosed with a running suture of 5-0 Prolene, the ascending aorta is vented for air, the aortic cross-clamp is removed, and coronary circulation is re-established (Fig . 3, D) . From this point on, the heart is beating and resuscitating while the pericardial patch is being sutured in place over the left pulmonary artery and the main pulmonary artery down to the pulmonary valve anulus. A patch of Dacron graft, joining the pericardial patch at the pulmonary anulus, is used

for enlargement of the right ventricular outflow tract (Fig. 3, E). The atrial septum is routinely inspected and an atrial septal defect or patent foramen ovale is closed by simple suturing. The patient is weaned off bypass in the usual manner, protamine is administered. the cannulas are removed, and routine chest closure is accomplished .

Comment The ascending aorta-right pulmonary artery anastomosis, originally described by Waterston, has been

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used frequently in the past for palliation in severely cyanotic infants.v" Recently, this palliative operative approach has been challenged in favor of the BlalockTaussig anastomosis in early infancy because of the lower initial and cumulative mortality rates at the time of total correction. 4. 15-18 There still remains however, a sizeable group of patients coming to total correction with a complicated, functioning, ascending aorta-right pulmonary artery anastomosis. If preoperative studies show normal flow and continuity between the main pulmonary artery and the right pulmonary artery without pressure gradients, the closure of the shunt may simply be carried out from inside the aorta via a small aortotomy. Unfortunately, however, many patients have gross distortion and stenosis of the right pulmonary artery and require more than a simple closure of the shunt for a successful outcome.?"!' Residual stenosis is not well tolerated and usually has to be relieved by repeat intervention and angioplasty of the pulmonary artery. 19 An additional complication involving breakdown of the closure and reopening of the shunt was reported by Yamamoto and associates." These two reasons led Ebert, Gay, and Oldham." to recommend complete division of the shunt with circular patch angioplasty of the pulmonary artery. Clarke," on the other hand, closed the shunt from inside the aorta with a cloth patch to prevent stenosis and kinking. Yamamoto and colleagues'? were the first to suggest transection of the ascending aorta and incontinuity patching of the unroofed right and left pulmonary arteries in two patients who required reoperation because of branch stenosis following simple closure during the total corrective operation. Transection of the ascending aorta, which is usually enlarged in these patients, gives excellent exposure to the main pulmonary artery and both branches and allows accurate angioplasty of the pulmonary artery under optimal conditions. Pericardium is easily sewn to the friable pulmonary artery and has adequate strength for the low pressure in the pulmonary circuit. As soon as the suture lines are carried to the left of the aorta, completing the angioplasty on the right pulmonary artery, the aorta is reanastomosed and the aortic crossclamp is removed. Thus the period of hypothermic ischemia is shortened. This step enables the surgeon to carry out this extensi ve reconstruction of the pulmonary artery at the initial corrective operation expeditiously. This seemingly radical approach not only ensures a smooth postoperative course by adequately relieving obstruction to the pulmonary flow but also eliminates the possibility of reopening shunts or restenoses at

Thoracic and Cardiovascular Surgery

primarily closed anastomotic sites, for which operative correction would be required at a later date. REFERENCES

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Pacifico AD, Bargeron LM, Kirklin JW: Primary total correction of tetralogy of Fallot in children less than four years of age. Circulation 48: 1085- 1091, 1973 Venugopal P, Subramanian S: Intracardiac repair of tetralogy of Fallot in patients under five years of age. Ann Thorac Surg 18:228-240, 1974 Puga FJ, DuShane JW, McGoon DC: Treatment of tetralogy of Fallot in children less than four years of age. J THoRAc CARDIOVASC SURG 64:247-253, 1972 Chiariello L, Meyer J, Wukasch DC, Hallman GL, Cooley DA: Intracardiac repair of tetralogy of Fallot. Five-year review of 403 patients. J THoRAc CARDIOVASC SURG 70:529-535, 1975 Waterston DJ, Stark J, Ashcraft KW: Ascending aorta to right pulmonary artery shunts. Experience with 100 patients. Surgery 72:897-904, 1972 Cooley DA, Hallman GL: Intrapericardial aortic right pulmonary arterial anastomosis. Surg Gynecol Obstet 122:1084-1086, 1966 Somerville J, Yacoub M, Ross DN: Aorta to right pulmonary artery anastomosis (Waterston operation) for cyanotic heart disease. Circulation 39:593-602, 1969 Truecome NJ, Bowman FO, Maim JR: Systemic pulmonary arterial Shunts in the first year of life. Circulation 49:508-511, 1974 Tay OJ, Engle MA, Ehlers KH: Early results and late development of the Waterston anastomosis. Circulation 50:220-229, 1974 Gay WA, Ebert PA: Aorta-to-right pulmonary artery anastomosis causing obstruction of the right pulmonary artery. Ann Thorac Surg 16:402-410, 1973 Reitman MJ, Galiotom FM, EI-Said GM: An ascending aorta to right pulmonary artery anastomosis. Circulation 49:952-957, 1974 Ebert PA, Gay WA, Oldham HN: Management of aorta-right pulmonary artery anastomosis during total correction of tetralogy of Fallot. Surgery 71:231-234, 1972 Clarke CP: Method of closure of the aorta-to-right pulmonary artery (Waterston) anastomosis during corrective operation. Ann Thorac Surg 16:411-413, 1973 Griepp RB, Stinson EB, Shumway NE: Profound local hypothermia for myocardial protection during open-heart surgery. J THoRAc CARDIOVASC SURG 66:731-741, 1973 Wood WC, McCue CM, Lower RR: Blalock-Taussig shunts in infants. Ann Thorac Surg 16:454-457, 1973 Chapra PS, Levy JM, Dacumos GC, Berkoff HA, Loring LL, Kahn DR: The Blalock-Taussig operation. The procedure of choice in the hypoxic infant with tetralogy of Fallot. Ann Thorac Surg 22:235-238, 1976 Ebert PA, Sabiston DC Jr: Surgical management of the

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tetralogy of Fallot. Influence of a previous systemic pulmonary anastomosis on the results of open correction. Ann Surg 165:806-813, 1967 18 Daily PA, Stinson EB, Griepp RB, Shumway NE: Tetralogy of Fallot. Choice of surgical procedure. J THORAC CARDIOVASC SURG 75:338-345, 1978

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19 Yamamoto N, Reul GJ, Kidd IN, Cooley DA, Hallman GL: A new approach to repair of pulmonary branch stenosis following ascending aorta-right pulmonary artery anastomosis. Ann Thorac Surg 21:237-242, 1976

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