Pulmonarv Arterv Plication: with Type I Trunms Arteriosus. A New S&gical Procedure for Small Infants

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1 Pulmonarv Arterv Plication: A New S&gical Procedure for Small Infants with Type I Trunms Arteriosus S. Bert Litwin, M.D., and David Z. Friedberg, M.D. ABSTRACT A new technique is reported for constriction of the pulmonary artery ostium as a palliative procedure in infants with type I truncus arteriosus. Pulmonary artery plication was performed without cardiopulmonary bypass, and this allowed intraoperative evaluation of the procedure. The lungs were protected from developing pulmonary vascular obstructive disease, and congestive heart failure resolved. The pulmonary arteries and the ostium grew with the child so that corrective surgery could be delayed until 4?h years of age, when a large (20 mm) valved extracardiac conduit could be placed. We believe this is a useful palliative operation, particularly for small, sick infants, and it deserves further evaluation. Truncus arteriosus is a serious congenital heart malformation that is associated with a high mortality in early life. Infants with this anomaly are at risk because of overperfusion of the lungs and pulmonary artery hypertension that results in refractory congestive heart failure, inanition, pulmonary vascular obstructive disease, or a combination of these problems. Early experience with pulmonary artery banding for type I truncus arteriosus was not satisfactory. Operative mortality was high, and there were technical problems related to placement of the band on a short main pulmonary artery [l-31. Occasionally the result was excessive constriction of one branch pulmonary artery with poor growth of that vessel or inadequate constriction of the second branch pulmonary artery and development of pulmo- From the Department of Thoracic and Cardiovascular Surgery and the Division of Surgery, Medical College of Wisconsin at the Milwaukee Children s Hospital, Milwaukee, WI. Accepted for publication Dec 21, Address reprint requests to Dr. Litwin, Director, Thoracic and Cardiovascular Suigery, Milwaukee Children s Hospital, 1700 W Wisconsin Ave, Milwaukee, WI nary vascular obstructive disease in the respective lung. Results of corrective surgery in older children have been reasonably good [4]. Such surgery includes detachment of the pulmonary arteries from the aorta, c1osu:re of the ventricular septa1 defect, and construction of vascular continuity between the right ventricle and pulmonary arteries with a valved extracardiac conduit. Ebert and co-workers [5, 6: have reported a very low mortality following totally corrective surgery in infancy; however, others [7-91 have reported a considerably higher risk in this age group. Because of these problems, we have used a new plication technique for restriction of pulmonary blood flow in infants with truncus arteriosus, while postpclning a corrective operation until later. We report successful pulmonary artery plication in an infant with type I truncus arteriosus and total repair at 4 years of age. Operative Technique The truncal vessel is approached through a left fourth intercostal space thoracotomy (Fig 1); a median stemotomy would also be suitable. The short main pulmonaiy artery is dissected, and small catheters for pressure monitoring and collection of blood samples are placed with snares in the ascending aorta, right pulmonary artery, and left pulmlonary artery, respectively. Monofilament mattress sutures with Teflon-felt pledgets are then placed in the aorta adjacent to the ostium of the pulmonary artery to constrict this orifice. Ideally, there is an increase in aortic pressure with simultaneous decrease in mean pressure in each pulrnonary artery to 30 to 50% of mean aortic pressure. Peripheral arterial oxygen saturation should fall to 70 to 80% (FIO~ = 50%). Application An infant was admitted to the Milwaukee Children s Hospital at the age of 3 days because 192 OOO3-4975/83/ Wl by The Society of Thoracic Surgeons

2 193 Case Report: Lihvin and Friedberg: Pulmonary Artery Plication RIGHT PULM. ARTERY LEFT ARTERY Fig 1. Operative technique of pulmonary artery plication: small catheters are placed with snares in the aorta (AO), the right pulmonary artery, and the left pulmonary artery (left). Plication sutures are placed in the aorta adjacent to the pulmonary artery ostium (right). of congestive heart failure. In addition to hepatomegaly and cardiomegaly, there was a grade 516 holosystolic murmur, audible along the left sternal border. Cardiac catheterization revealed type I truncus arteriosus with systemic pressure in the right ventricle. The infant was treated with digitalis and diuretics but was readmitted at the age of 3 months with inanition and refractory congestive heart failure. During this hospitalization, a left thoracotomy was performed and pulmonary artery plication was carried out (Fig 2). There was a substantial reduction in right and left pulmonary artery pressures (Table), while peripheral arterial oxygen saturation fell from 91 to 76% (Fx02 = 50%). Postoperatively, a continuous murmur was heard along the left sternal border. Congestive heart failure cleared, Fig 2. Anatomy as seen through a left thoracotomy at the time of plication (the infant's head is to the right). (A0 = ascending aorta; LPA = left pulmonary artery; RPA = right pulmonary artery.) and the baby was discharged on a regimen of digoxin. Repeat cardiac catheterization performed at 3 years of age revealed mild pulmonary artery hypertension. Other intracardiac pressures are listed in the Table. An aortogram showed a small pulmonary artery ostium (Fig 3). Corrective surgery was performed at 4% years of age using cardiopulmonary bypass, moderate hypothermia (26"C), and profound local cardiac cooling with cardioplegia solution injected every 20 to 25 minutes. The main pulmonary artery was opened longitudinally, and Hemodynamic Data Intraoperative (Age: 3 Months) Pressure Measurement Before Plication After Plication Age: 3 Years Right ventricle ii9no Main pulmonary artery (36) Left pulmonary artery (50) 42/30 (36) (39) Right pulmonary artery 48/35 (46) 36/24 (29)... Aorta 98/28 122/47 (77)... Peripheral arterial O2 saturation (YO)

3 194 The Annals of Thoracic Surgery Vol 35 No 2 February 1983 satisfactory, and the child was discharged on the sixth postoperative day. One week later a slow-growing organism, Propionibacterium, was recovered from culture of a sample from the valved conduit taken during the operation. The organism was sensitive to penicillin. The child was asymptomatic, but admission to an outside hospital for treatment was arranged. Intravenous antibiotics were given for eight weeks. The patient is well one and one-half years following operation. Fig 3. Angiogram at 3 years of age. The pulmonary artery ostium is restrictive (arrow). (A0 = ascending aorta; RPA = right pulmonary artery; LPA = left pulmonary artery.) the pulmonary artery ostium was closed with a Dacron patch [lo]. The ostium measured approximately 10 mm, and the original plication stitches were intact. Through a high right ventriculotomy, a large ventricular septal defect was closed with a second Dacron patch. Finally, a 20 mm valved conduit+ was placed between the right ventriculotomy and the main pulmonary arteriotomy. Intraoperative pressures after the repair were as follows: right ventricle 721, main pulmonary artery 57/21 (mean, 30), left ventricle 1041, and radial artery 103/55. A biopsy specimen from the right lung showed no changes of pulmonary vascular obstructive disease. Postoperatively, dopamine was required for 24 hours; atrioventricular dissociation was present during this time, after which it reverted to normal sinus rhythm. On the first postoperative day, right ventricular pressure was 42 and the radial artery pressure was The postoperative recovery was otherwise *Edwards Laboratories, Santa Ana, CA. Comment The natural history of truncus arteriosus includes a high mortality in early life due to refractory congestive heart failure or pulmonary vascular obstructive disease. Although pulmonary artery banding has been a useful operation for many anomalies with a large left-to-rig:ht shunt, it has now been abandoned for infants with truncus arteriosus by most centers. Operative mortality is high [ 1-31 and long-term palliation unpredictable due to technical difficulties related to placing a band on a short main pulmonary artery. At times, one branch pulmonary artery is inadequately constricted, allowing for development of unilateral pulmonary vascular obstructive disease. Likewise, one pulmonary artery may be severely constricted, resulting in poor growth of that vessel and technical difficulties with removal of the band at the time of later total repair. Corrective surgery in older children with truncus arteriosus has been performed successfully for many yezrs [4]. The operation includes detachment of the pulmonary arteries from the truncal vessel:, closure of the ventricular septal defect with routing of left ventricular blood to the aorta, and establishment of vascular continuity between the right ventricle and the pulmonary arterics with an extracardiac conduit. In recent years, Ebwt and colleagues [5, 61 have performed primary "total repair" in infants under 1 year of age with 12% operative mortality. Other surgeons [7-91 have not attained the same low inortality following "pri-

4 195 Case Report: Litwin and Friedberg: Pulmonary Artery Plication mary repair" of truncus arteriosus in infancy. In addition, the operation is not a definitive repair since the infant always outgrows the small extracardiac conduit, which has to be replaced at a later age. Because of our dissatisfaction with traditional operations for small, sick infants with truncus arteriosus, we have used a different technique (pulmonary artery plication) to constrict the pulmonary artery ostium. The operation is simple and can be performed rapidly in even the smallest neonates. Cardiopulmonary bypass is not required, and intraoperative evaluation of the procedure is facilitated. Mean pressure in each pulmonary artery is reduced to 30 to 50% of mean aortic pressure. A concomitant rise in systemic pressure is typical. We also use these indicators to determine the effectiveness of the banding operation in infants and children with other anomalies that include a large left-to-right shunt. Additionally, peripheral arterial oxygen saturation should fall after pulmonary artery plication, reaching a value of 70 to 80% (FIO~ = 50%), similar to that which is ideal after creation of an ascending aorta-right pulmonary artery (Waterston) shunt in infants with inadequate pulmonary blood flow. Pulmonary artery plication, therefore, changes the anatomy and hemodynamics in an infant with truncus arteriosus and a large pulmonary artery ostium to anatomy and hemodynamics that are similar to pulmonary atresia and Waterston shunt. Mansfield and associates [ll] have used the same analogy in advocating a slightly different palliative operation for infants with truncus arteriosus. After establishing a subclavian-pulmonary artery anastomosis, they have completely closed the pulmonary artery ostium. This procedure would probably not be useful in infants with types I1 and I11 truncus arteriosus, while pulmonary artery plication would be effective. Mistrot and colleagues [121 and Murphy (personal communication, 1981) have created pulmonary ostial stenosis in infants with truncus arteriosus with the aid of cardiopulmonary bypass. Using this technique, the surgeon has to estimate the degree of ostial constriction. Our operation has the advantage of allowing the surgeon to evaluate the great vessel pressures and peripheral arterial oxygen saturation intraoperatively while the pulmonary artery is progressively constricted. Unlike traditional pulmonary artery banding, plication allows the constricted pulmonary artery ostium to grow with the patient. This occurred in our patient so that total repair could be delayed until a later age, when a large (20 mm) extracardiac conduit could be placed. Pulmonary arteries were well preserved, and there was little intrapericardial scarring to cause a difficult dissection at the time of total repair. The lungs were well protected, as demonstrated by a low right ventricular pressure after the repair and absence of pulmonary vascular obstructive disease as seen on a lung biopsy specimen at the time of successful total repair at age 4 years. We recognize that the latter test alone does not rule out lung changes. It appears, therefore, that pulmonary artery plication in early infancy, followed by corrective surgery later, involves a lesser operation in a small infant and a larger operation when the child is older. "Total repair" as the primary operation with later replacement of the extracardiac conduit involves a larger operation in infancy and a lesser operation when the child is older. We believe pulmonary artery plication is a useful operation for palliation of infants with types I, 11, or I11 truncus arteriosus and think the procedure deserves further evaluation. References 1. Singh AK, de Leva1 MR, Pincott JR, Stark J: Pulmonary artery banding for truncus arteriosus in the first year of life. Circulation 54:Suppl 3:17, McFaul RC, Mair DD, Feldt RH, et al: Truncus arteriosus and previous pulmonary arterial banding: clinical and hemodynamic assessment. Am J Cardiol 38:626, Mahle S, Nicoloff DM, Knight L, Moller JH: Pulmonary artery banding: long-term results in 63 patients. Ann Thorac Surg 27:216, Marcelletti C, McGoon DC, Danielson GK, et al: Early and late results of surgical repair of truncus arteriosus. Circulation 55:636, Ebert PA, Robinson SJ, Stanger P, Engle MA: Pulmonary artery conduit in infants younger

5 196 The Annals of Thoracic Surgery Vol 35 No 2 February 1983 than six months of age. J Thorac Cardiovasc Surg 72351, Ebert P: Truncus arteriosus-technique and results. Presented at the conference on Current Controversies and Techniques in Congenital Heart Surgery, Baltimore, MD, May 8-9, Appelbaum A, Bargeron LM, Pacific0 AD, Kirklin JW: Surgical treatment of truncus arteriosus with emphasis on infants and small children. J Thorac Cardiovasc Surg 71:436, Stark J, Gandhi D, de Leva1 M, et al: Surgical treatment of persistent truncus arteriosus in the first year of life. Br Heart J 40:1280, Parenzan L, Crupi G, Alfieri 0, et al: Surgical repair of persistent tru.ncus arteriosus in infancy. Thorac Cardiovasc Surg 28:18, Stewart S: Correction of truncus arteriosus after pulmonary artery banding. Ann Thorac Surg 20:713, Mansfield P, Hall DG, Rittenhouse EA, et al: Cardiac surgery under ilge two years-a review. J Thorac Cardiovasc Surg 77:816, Mistrot JJ, Varco RL,. Nicoloff DM: Palliation of infants with truncus arteriosus through creation of a pulmonary artery ostial stenosis. Ann Thorac Surg 22495, 1976