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Waterston anastomosis for initial palliation of tetralogy of Fallot
J
THORAC CARDIOVASC SURG
82: 176-181, 1981
Waterston anastomosis for initial palliation of tetralogy of Fallot Two hundred twenty-seven patients (median age 5.4 months) in whom a Waterston anastomosis was done for initial palliation of tetralogy of Fallot between 1966 and 1979 were studied. Twelve patients died in the hospital (5.3%; 70% confidence limits, 3.8% to 7.3%). Young age, low weight, and poor clinical condition did not appear to be incremental risk factors, whereas a too large or a too small shunt was largely responsible for the hospital mortality and morbidity. Follow-up information was available in all the 215 patients discharged from the hospital. At the last follow-up visit, before any further surgical procedure, 74% of the patients were clinically in good condition. By actuarial methods, 97.7% of hospital survivors were alive and 95.8% were event-free at and beyond 3 years postoperatively. Eighty-six patients have been catheterized in preparation for secondary repair (mean interval between Waterston shunt and catheterization, 2.9 ± 1.38 years). One patient developed pulmonary vascular disease, four acquired pulmonary atresia, and 14 had a severe kinking of the right pulmonary artery at the site of the anastomosis.
Lucio Parenzan, M.D., Ottavio Alfieri, M.D., Vittorio Vanini, M.D., Tiziano Bianchi, M.D., Massimo Villani, M.D., Roberto Tiraboschi, M.D., Giancarlo Crupi, M.D., and Giuseppe Locatelli, M.D., Bergamo, Italy
Although in the past few years considerable enthusiasm has been generated for primary repair of tetralogy of Fallot, recent reports indicate that a preliminary palliative operation is advisable in small infants, particularly if the anatomy is "unfavorable. ,,\, 2 Obviously, infants whose initial treatment is a shunt are exposed to the risks associated with the shunt operation, the interval between shunt and repair, and the intracardiac repair. The Blalock-Taussig anastomosis is commonly considered the procedure of choice for palliation of hypoxic infants with tetralogy of Fallot. Early''- 4 and long-term" results with this operation have been reported. Through the years, we have performed an anastomosis between the ascending aorta and the right pulmonary artery (Waterston shunt) in patients with this cardiac anomaly. This study evaluates the Waterston shunt as an initial palliative operation for tetralogy of From the Division of Cardiac Surgery, Ospedali Riuniti, 24100 Bergamo, Italy. Received for publication Oct. 24, 1980. Accepted for publication Dec. 16, 1980. Address for reprints: Lucio Parenzan, M.D., Division of Cardiac Surgery, Ospedali Riuniti, 24100 Bergamo, Italy.
176
Fallot. Since our results with corrective operations after a Waterston anastomosis have been already analyzed," only mortality and morbidity associated with the shunt operation and the events which occurred before any further surgical procedure will be presented here. Patients
From 1966 to 1979, 588 patients with tetralogy of Fallot have been admitted to our institution for their initial surgical treatment, either palliative or corrective (Table I). Patients with congenital pulmonary atresia and ventricular septal defect are excluded from this series. The size of the right and left pulmonary arteries and the size of the main pulmonary trunk and anulus were extremely variable, ranging from "severely hypoplastic" to "normal." A segmental stenosis of one of the two pulmonary arteries or stenosis at the bifurcation was not uncommon. Of these 588 patients, 227 (39%) received a Waterston shunt as initial palliation. The age of this group ranged from 3 days to 11 years (median, 5.4 months). The smallest patient weighed 2.3 kg, and 31 weighed less than 3.5 kg. Severe cyanosis or anoxic episodes or both were the indication for operation in all patients. In 39 patients (17%) the clinical condition was so poor at the time of admission that the Waterston shunt
0022-5223/81/080176+06$00.60/0 © 1981 The C. V. Mosby Co.
Volume 82
Waterston anastomosis for tetralogy of Fallot
Number 2
August. 1981
177
Fig. 1. Instruments for measuring the length of the aortotomy used in constructing a Waterston shunt.
was done on an emergency basis. Only in a few patients was the operation done without a previous hemodynamic and angiocardiographic study . In these cases, however, the clinical diagnosis of tetralogy of Fallot was later confirmed by cardiac catheterization.
Operation The anastomosis is preferably done through a right posterolateral thoracotomy in the fourth intercostal space behind the superior vena cava . In this series the operation was performed intrapericardially through an anterolateral thoracotomy in only 27 patients (12%). The aorta is rotated anteriorly in order to construct the anastomosis as much as possible posteriorly and thereby reduce the incidence of right pulmonary artery kinking at the site of the anastomosis. Particular attention is devoted to the size of the aortotomy, which varies according to the body weight (Table II). The size of the aortotomy is precisely measured through use of graduated instruments as illustrated in Fig. I. A continuous 6-0 or 7-0 polypropylene suture is employed for the anastomosis, which is now greatly facilitated by the use of magnification glasses. The intraoperative support includes the infusion of a norepinephrine solution to maintain the systolic blood
Table I. Surgical treatment of 588 patients with tetralogy of Fallot (1966-1979) _ _ _ _ _ _ _ _..,jl~-M-e-dl-
·a-n-ag-e-(-m-o-)
Waterston shunt Blalock-Taussig shunt
273 227 88
45 .5 5.4
46 39
15.2
15
Totals
588
20.6
100
Primary repair
....,~
pressure above 90 mm Hg throughout the procedure . A maintenance dosage of digitalis is usually given during hospitalization and continued after discharge from the hospital if needed.
Method The records for each patient were reviewed individually to assure proper categorization and completeness and accuracy of the data. The patients who were discharged from the hospital have been evaluated periodically by direct physical examination and chest roentgenograms . The clinical condition was classified as follows: good -absent or minimal cyanosis and no need for medication; poor-persistence of cyanosis and/or an-
The Journal of Thoracicand Cardiovascular Surgery
1 78 Parenzan et al.
Table II. Optimal length of aortotomy for the Waterston shunt Aortotomy (mm)
Weight (kg) 2.5-4 4-6.5 6.5-9 9-12 12-15
2-2.5
>2 >3 >3.5 >6 >6
0:51 >1 :53 >3 :56 >6:512 >12 :524 >24 Totals
I
No.
No.
7 24 85 91 20
I I 5 4
227
I
%
I
CL
1
14 4 6 4 5
2%-41% 0%-13% 3%-10% 2%-8% 1%-16%
12
5.3
3.8%-7.3%
Legend: p = 0.75 for difference in hospital mortality between patients weighing 053.5 kg and patients weighting >3.5 kg.
No.
No.
8 45 69 42 38 25
I I 4 2 3 I
12 2 6 5 8 4
2%-36% 0%-7% 3%-10% 2%-11% 3%-15% 0%-13%
227
12
5.3
3.8%-7.3%
%
:53 :53.5 :56 :510 >10
Totals
Hospital mortality
I
Hospital mortality Weight (kg)
3 3.5 4 4.5-5
Table III. Waterston shunt in patients with tetralogy of Fallot (1966-1979)
Age (mo)
Table IV. Waterston shunt in patients with tetralogy of Fallot (1966-1979)
CL
Legend: p = 0.35 for difference in hospital mortality between patients 05 1 month and patients > 1 month of age.
oxic episodes or, alternatively, need for digitalis and diuretics; and fair-clinical status between the two previously defined conditions. Survival and event-free actuarial curves have been constructed by the reduced sample method? for all the patients who survived the operation; those having a second operation are considered as untraced from that date. The hemodynamic data and the angiocardiographic features of the patients who had a cardiac catheterization after the Waterston shunt have also been examined. The percentage of hospital mortality in the different age groups as well as the event-free percentage in the actuarial analysis, is presented with the 70% confidence limits (CL). The significance level of the difference between proportions is assessed by the chi square test.
Early results The overall hospital mortality was 5.3% (CL = 3.8% to 7.3%) (Tables III and IV). The age and the weight of the patients did not appear to influence significantly the operative mortality. Although the hospital mortality was higher in the first month of life, the p value for the difference in mortality between the patients younger and those older than 1 month of age is 0.35. Of the 31 patients weighing less than 3.5 kg at operation, only two died (p = 0.75 for the difference in
Table V. Waterston shunt in patients with tetralogy of Fallot (1966-1979) Causes of hospital death Pulmonary edema Persistent hypoxia Respiratory infection Sepsis Cardiac arrest on the table Total
No. 4 3 2 2 1 12
hospital mortality between these patients and the rest of the patients). Also, the preoperative condition was not a determinant of the hospital mortality. Among the 39 patients who underwent the operation on an emergency basis, only two died (p = 0.96 for the difference in mortality between these and the rest of the patients). The causes of death in the 12 patients who died within 30 days after operation are shown in Table V. Obviously, the shunt was too small or not "functioning" in the three patients who died of persistent hypoxia, and the shunt was too large in the four who died of pulmonary edema. The patient who had a cardiac arrest and died in the operating room had a severe form of tetralogy of Fallot, a small ductus arteriosus being almost exclusively the source of pulmonary blood flow. Two patients died of bilateral bronchopneumonia during their hospitalization, and two others had a wound infection and died of sepsis. No particular relation was observed between the age of the patients and the causes of hospital death. Although the hospital course was generally smooth, a number of patients had nonfatal complications during the postoperative period (Table VI).
Late results Follow-up information was available in all 215 patients who were discharged from the hospital. After the Waterston shunt, 105 patients did not have any fur-
Volume 82 Number 2 August, 1981
Waterston anastomosis for tetralogy of Fallot
179
Table VI. Waterston shunt in patients with tetralogy of Fallot (1966-1979) Nonfatal hospital complications
No.
Heart failure Respiratory infection Wound infection Enteritis
10* 7 5 2
Good
Fair Poor
• In one case surgical revision of the shunt was carried out.
Fig. 2. Status of the patients who received a Waterston shunt at the follow-up visit before any further operation.
Table VII. Waterston shunt in patients with tetralogy of Fallot (1966-1979) Events after discharge from the hospital
No.
Hemiparesis Femoral artery thrombosis Brain abscess Meningitis
4 1*
It It
• Amputation of the leg. t Death.
ther surgical procedure (mean follow-up, 2.3 ± 1.25 years); 90 patients underwent secondary repair on an elective basis (mean interval between the Waterston shunt and the repair, 3.4 ± 1.48 years); 10 patients (seven for persistent cyanosis and three for some degree of heart failure) underwent correction before reaching the elective age (mean interval between the shunt and the repair, 0.9 ± 0.71); and 10 others required further palliation for persistent symptoms (mean interval between the initial Waterston shunt and the second palliative operation, 1.5 ± 1.29 years). The clinical status at the time of the last follow-up visit before any further surgical procedure was categorized as good in 74%, fair in 17%, and poor in 9% of the patients who survived a Waterston shunt (Fig. 2). The events which occurred after discharge from the hospital are listed in Table VII; two of them (a cerebral abscess and meningitis) were fatal. By actuarial methods, therefore, 97.7% (CL = 95.2% to 99.3%) of hospital survivors were alive and 95.8% (CL = 93.3% to 97.4%) were event-free at and beyond 3 years postoperatively (longest follow-up 7.3 years). Survival and event-free actuarial curves are shown in Fig. 3.
Catheterization and angiocardiography Eighty-six of the patients who survived the Waterston shunt had cardiac catheterization and angiocardiograms in preparation for secondary repair. The mean interval between the palliative procedure and the catheterization was 2.9 ± 1.38 years. Only one patient, who surprisingly had had the Waterston shunt only 2 years earlier, was found to have pulmonary hy-
pertension with pulmonary vascular disease and was considered inoperable. In the remaining patients the mean pressure in the main pulmonary artery was 15 ± 4.9 mm Hg. In four children (about 5% of the 86 who were catheterized), pulmonary atresia developed in the interval between the shunt and the prerepair study. The angiocardiographic studies showed some kinking at the site of the anastomosis in 38 patients (44%); in 14 others (16%) only the right pulmonary artery was visualized by the aortogram, there being no retrograde flow to visualize the proximal right pulmonary artery or main and left arteries. In a previous study, we" have demonstrated and quantitated the growth of the pulmonary arteries and particularly of the pulmonary anulus after the Waterston anastomosis.
Discussion Although we" occasionally have performed primary repair of tetralogy of Fallot in children in the first year of life, a palliative operation has always been the treatment of choice in this age group. In particular, the Waterston shunt has been used preferentially, while the Blalock- Taussig anastomosis has been performed less commonly, generally in patients older than 6 months. This attitude gave us the opportunity of studying a large number of patients who received a Waterston shunt as initial palliation of tetralogy of Fallot. Our hospital mortality compares favorably with those of other series, to- t2 and it is similar to that recently reported by Alvarez-Diaz and associates. 13 The age and the weight of the patients, as well as the preoperative condition, do not appear to influence significantly the operative mortality. Analysis of our results clearly indicates that the size of the shunt stoma is the crucial point of the Waterston operation. Despite an accurate calibration of the aortotomy according to the body weight, a number of patients had too small or too large a shunt possibly because of an inadequate technique of performing the
The Journal of Thoracic and Cardiovascular Surgery
1 80 Parenzan et at.
1.00 0.99 P R 0 P 0 R T I 0 N
--
-~
0.98 .......
SURVIVAL
_------------------- --
0.97 0.96
EVENT- FREE
0.95 0.94 0.93 0.92 0.91
N:170
N:119
N:73
N:24
N:9
N:3
N:l
5
6
7
0.90
1
2
3
4
YEARS AFTER THE WATERSTON SHUNT Fig. 3. Survival (dotted line) and event-free (continuous line) actuarial curves computed for the 215 patients who were discharged from the hospital after a Waterston shunt. Confidence limits are indicated by the vertical bars.
anastomosis. This error was largely responsible for the hospital mortality and morbidity. Furthermore, some of the patients who survived either required correction earlier than planned or required a further palliation, again for a shunt that was either too small or too large. We have learned to evaluate the shunt on the operating table by palpating the thrill on the right pulmonary artery after the completion of the anastomosis. If the shunt appears to be too small, we redo the anastomosis; if it is too large, we reduce the stoma in the manner already described. 14 The events which occurred in our patients after discharge from the hospital are not very uncommon in patients with persistent right-to-left shunts across the ventricular septum and have also been reported following a Blalock-Taussig shunt. 5 Pulmonary vascular obstructive disease is commonly considered a risk associated with the Waterston shunt. 15 However, our hemodynamic studies in a large number of patients reveal that pulmonary hypertension with a severe degree of pulmonary vascular disease is extremely rare after a Waterston shunt. "Kinking" of the right pulmonary artery at the site of the anastomosis is another common criticism of the Waterston operation. 16 In a recent review of our experience with repair of tetralogy of Fallot after a Waterston operation, we" found that the patients who required patch-graft enlargement of the right pulmonary artery because of severe kinking and stenosis at the site of the anastomosis had a postrepair right ventricular- to-left ventricular pressure ratio similar to that of the rest of the patients.
Growth of the pulmonary anulus, which is more pronounced after the Waterston than after the BlalockTaussig anastomosis," is an argument in favor of the Waterston shunt, since the use of a transanular patch in repair of tetralogy of Fallot has been associated with a higher hospital mortality. r. 6 The short operating time and lack of need for interruption of the subclavian artery are other advantages of the Waterston over the Blalock-Taussig shunt. All these considerations support our preferential use of the Waterston shunt as initial palliation for tetralogy of Fallot.
2
3
4
5
6
REFERENCES Kirklin JW, Blackstone EH, Pacifico AD, Brown RH, Bargeron LH Jr: Routine primary repair versus 2-stage repair of tetralogy of Fallot. Circulation 60:373-386, 1979 Stephenson LW, Friedman S, Edmunds LH Jr: Staged surgical management of tetralogy of Fallot in infants. Circulation 58:837-841, 1978 Chopra PS, Levy JM, Dacumos GC Jr, Berkoff HA, Loring LL, Kahn DR: The Blalock-Taussig operation. The procedure of choice in hypoxic infants with tetralogy of Fallot. Ann Thorac Surg 22:235-238, 1976 Arciniegas E: Discussion of Castaneda AR, Freed MD, Williams RG, Norwood WI: Repair of tetralogy of Fallot in infancy. J THoRAc CARDIOVASC SURG 74:372-381, 1977 Taussig HB, Crawford H, Pelargonio S, Zacharioudakis S: Ten to thirteen year follow-up on patients after a Blalock-Taussig operation. Circulation 25:630-634, 1962 Alfieri 0, Locatelli G, Bianchi T, Vanini V, Parenzan L:
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August, 1981
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9
10
II
Repair of tetralogy of Fallot after Waterston anastomosis. J THORAC CARDIOVASC SURG 77:826-831, 1979 Berkson J, Gage RP: Calculation of survival rates for cancer. Mayo Clin Proc 25:270-286, 1950 Alfieri 0, Blackstone EH, Parenzan L: Growth of the pulmonary anulus and pulmonary arteries after the Waterston anastomosis. J THORAC CARDIOVASC SURG 78:440-444, 1979 Parenzan L, Alfieri 0: Correction of tetralogy of Fallot in the first year of life, Paediatric Cardiology, RH Anderson, EA Shinebourne, eds., London, 1978, Churchill Livingstone, p 289 Bernhard WF, Jones JE, Friedberg DZ, Litwin SB: Ascending aorta-right pulmonary artery shunt in infants and older patients with certain types of cyanotic congenital heart disease. Circulation 43:580-584, 1971 Barratt-Boyes BG: Primary definitive intracardiac operation in infants: Tetralogy of Fallot, Advances in Cardiovascular Surgery, JW Kirklin, ed., New York, 1973, Grune & Stratton, Inc., p 156
Waterston anastomosis for tetralogy of Fallot
I8I
12 Idriss FS, Cavallo CA, Nikaidoh H, Paul MH, Koopot R, Muster AJ: Ascending aorta-right pulmonary artery shunt. J Thorac Cardiovasc Surg 71:49-57, 1976 13 Alvarez-Diaz F, Sanz E, Sanchez PA, Cordovilla G, Celemind D, Moreno F, Borches D, Gutierrez JR: Fallot's tetralogy: Palliation and Repair With a Previous Shunt, Paediatric Cardiology, RH Anderson, EA Shinebourne, eds., London, 1978, Churchill Livingstone, p 273 14 Alfieri 0, Bianchi T, Tiraboschi R, Parenzan L: Surgical revision of Waterstons anastomosis for intractable heart failure. Surg Italy 6:19-24, 1976 15 Newfeld EA, Wadman JD, Paul MH, Muster AJ, Cole RB, Idriss F, Ricker W: Pulmonary vascular disease after systemic-pulmonary arterial shunt operations. Am J Cardiol 39:715-720, 1977 16 Gay WA Jr, Ebert PA: Aorta to right pulmonary artery anastomosis causing obstruction of the right pulmonary artery. Management during correction of tetralogy of Fallot. Ann Thorac Surg 16:402-410, 1973
THORAC CARDIOVASC SURG
82: 176-181, 1981
Waterston anastomosis for initial palliation of tetralogy of Fallot Two hundred twenty-seven patients (median age 5.4 months) in whom a Waterston anastomosis was done for initial palliation of tetralogy of Fallot between 1966 and 1979 were studied. Twelve patients died in the hospital (5.3%; 70% confidence limits, 3.8% to 7.3%). Young age, low weight, and poor clinical condition did not appear to be incremental risk factors, whereas a too large or a too small shunt was largely responsible for the hospital mortality and morbidity. Follow-up information was available in all the 215 patients discharged from the hospital. At the last follow-up visit, before any further surgical procedure, 74% of the patients were clinically in good condition. By actuarial methods, 97.7% of hospital survivors were alive and 95.8% were event-free at and beyond 3 years postoperatively. Eighty-six patients have been catheterized in preparation for secondary repair (mean interval between Waterston shunt and catheterization, 2.9 ± 1.38 years). One patient developed pulmonary vascular disease, four acquired pulmonary atresia, and 14 had a severe kinking of the right pulmonary artery at the site of the anastomosis.
Lucio Parenzan, M.D., Ottavio Alfieri, M.D., Vittorio Vanini, M.D., Tiziano Bianchi, M.D., Massimo Villani, M.D., Roberto Tiraboschi, M.D., Giancarlo Crupi, M.D., and Giuseppe Locatelli, M.D., Bergamo, Italy
Although in the past few years considerable enthusiasm has been generated for primary repair of tetralogy of Fallot, recent reports indicate that a preliminary palliative operation is advisable in small infants, particularly if the anatomy is "unfavorable. ,,\, 2 Obviously, infants whose initial treatment is a shunt are exposed to the risks associated with the shunt operation, the interval between shunt and repair, and the intracardiac repair. The Blalock-Taussig anastomosis is commonly considered the procedure of choice for palliation of hypoxic infants with tetralogy of Fallot. Early''- 4 and long-term" results with this operation have been reported. Through the years, we have performed an anastomosis between the ascending aorta and the right pulmonary artery (Waterston shunt) in patients with this cardiac anomaly. This study evaluates the Waterston shunt as an initial palliative operation for tetralogy of From the Division of Cardiac Surgery, Ospedali Riuniti, 24100 Bergamo, Italy. Received for publication Oct. 24, 1980. Accepted for publication Dec. 16, 1980. Address for reprints: Lucio Parenzan, M.D., Division of Cardiac Surgery, Ospedali Riuniti, 24100 Bergamo, Italy.
176
Fallot. Since our results with corrective operations after a Waterston anastomosis have been already analyzed," only mortality and morbidity associated with the shunt operation and the events which occurred before any further surgical procedure will be presented here. Patients
From 1966 to 1979, 588 patients with tetralogy of Fallot have been admitted to our institution for their initial surgical treatment, either palliative or corrective (Table I). Patients with congenital pulmonary atresia and ventricular septal defect are excluded from this series. The size of the right and left pulmonary arteries and the size of the main pulmonary trunk and anulus were extremely variable, ranging from "severely hypoplastic" to "normal." A segmental stenosis of one of the two pulmonary arteries or stenosis at the bifurcation was not uncommon. Of these 588 patients, 227 (39%) received a Waterston shunt as initial palliation. The age of this group ranged from 3 days to 11 years (median, 5.4 months). The smallest patient weighed 2.3 kg, and 31 weighed less than 3.5 kg. Severe cyanosis or anoxic episodes or both were the indication for operation in all patients. In 39 patients (17%) the clinical condition was so poor at the time of admission that the Waterston shunt
0022-5223/81/080176+06$00.60/0 © 1981 The C. V. Mosby Co.
Volume 82
Waterston anastomosis for tetralogy of Fallot
Number 2
August. 1981
177
Fig. 1. Instruments for measuring the length of the aortotomy used in constructing a Waterston shunt.
was done on an emergency basis. Only in a few patients was the operation done without a previous hemodynamic and angiocardiographic study . In these cases, however, the clinical diagnosis of tetralogy of Fallot was later confirmed by cardiac catheterization.
Operation The anastomosis is preferably done through a right posterolateral thoracotomy in the fourth intercostal space behind the superior vena cava . In this series the operation was performed intrapericardially through an anterolateral thoracotomy in only 27 patients (12%). The aorta is rotated anteriorly in order to construct the anastomosis as much as possible posteriorly and thereby reduce the incidence of right pulmonary artery kinking at the site of the anastomosis. Particular attention is devoted to the size of the aortotomy, which varies according to the body weight (Table II). The size of the aortotomy is precisely measured through use of graduated instruments as illustrated in Fig. I. A continuous 6-0 or 7-0 polypropylene suture is employed for the anastomosis, which is now greatly facilitated by the use of magnification glasses. The intraoperative support includes the infusion of a norepinephrine solution to maintain the systolic blood
Table I. Surgical treatment of 588 patients with tetralogy of Fallot (1966-1979) _ _ _ _ _ _ _ _..,jl~-M-e-dl-
·a-n-ag-e-(-m-o-)
Waterston shunt Blalock-Taussig shunt
273 227 88
45 .5 5.4
46 39
15.2
15
Totals
588
20.6
100
Primary repair
....,~
pressure above 90 mm Hg throughout the procedure . A maintenance dosage of digitalis is usually given during hospitalization and continued after discharge from the hospital if needed.
Method The records for each patient were reviewed individually to assure proper categorization and completeness and accuracy of the data. The patients who were discharged from the hospital have been evaluated periodically by direct physical examination and chest roentgenograms . The clinical condition was classified as follows: good -absent or minimal cyanosis and no need for medication; poor-persistence of cyanosis and/or an-
The Journal of Thoracicand Cardiovascular Surgery
1 78 Parenzan et al.
Table II. Optimal length of aortotomy for the Waterston shunt Aortotomy (mm)
Weight (kg) 2.5-4 4-6.5 6.5-9 9-12 12-15
2-2.5
>2 >3 >3.5 >6 >6
0:51 >1 :53 >3 :56 >6:512 >12 :524 >24 Totals
I
No.
No.
7 24 85 91 20
I I 5 4
227
I
%
I
CL
1
14 4 6 4 5
2%-41% 0%-13% 3%-10% 2%-8% 1%-16%
12
5.3
3.8%-7.3%
Legend: p = 0.75 for difference in hospital mortality between patients weighing 053.5 kg and patients weighting >3.5 kg.
No.
No.
8 45 69 42 38 25
I I 4 2 3 I
12 2 6 5 8 4
2%-36% 0%-7% 3%-10% 2%-11% 3%-15% 0%-13%
227
12
5.3
3.8%-7.3%
%
:53 :53.5 :56 :510 >10
Totals
Hospital mortality
I
Hospital mortality Weight (kg)
3 3.5 4 4.5-5
Table III. Waterston shunt in patients with tetralogy of Fallot (1966-1979)
Age (mo)
Table IV. Waterston shunt in patients with tetralogy of Fallot (1966-1979)
CL
Legend: p = 0.35 for difference in hospital mortality between patients 05 1 month and patients > 1 month of age.
oxic episodes or, alternatively, need for digitalis and diuretics; and fair-clinical status between the two previously defined conditions. Survival and event-free actuarial curves have been constructed by the reduced sample method? for all the patients who survived the operation; those having a second operation are considered as untraced from that date. The hemodynamic data and the angiocardiographic features of the patients who had a cardiac catheterization after the Waterston shunt have also been examined. The percentage of hospital mortality in the different age groups as well as the event-free percentage in the actuarial analysis, is presented with the 70% confidence limits (CL). The significance level of the difference between proportions is assessed by the chi square test.
Early results The overall hospital mortality was 5.3% (CL = 3.8% to 7.3%) (Tables III and IV). The age and the weight of the patients did not appear to influence significantly the operative mortality. Although the hospital mortality was higher in the first month of life, the p value for the difference in mortality between the patients younger and those older than 1 month of age is 0.35. Of the 31 patients weighing less than 3.5 kg at operation, only two died (p = 0.75 for the difference in
Table V. Waterston shunt in patients with tetralogy of Fallot (1966-1979) Causes of hospital death Pulmonary edema Persistent hypoxia Respiratory infection Sepsis Cardiac arrest on the table Total
No. 4 3 2 2 1 12
hospital mortality between these patients and the rest of the patients). Also, the preoperative condition was not a determinant of the hospital mortality. Among the 39 patients who underwent the operation on an emergency basis, only two died (p = 0.96 for the difference in mortality between these and the rest of the patients). The causes of death in the 12 patients who died within 30 days after operation are shown in Table V. Obviously, the shunt was too small or not "functioning" in the three patients who died of persistent hypoxia, and the shunt was too large in the four who died of pulmonary edema. The patient who had a cardiac arrest and died in the operating room had a severe form of tetralogy of Fallot, a small ductus arteriosus being almost exclusively the source of pulmonary blood flow. Two patients died of bilateral bronchopneumonia during their hospitalization, and two others had a wound infection and died of sepsis. No particular relation was observed between the age of the patients and the causes of hospital death. Although the hospital course was generally smooth, a number of patients had nonfatal complications during the postoperative period (Table VI).
Late results Follow-up information was available in all 215 patients who were discharged from the hospital. After the Waterston shunt, 105 patients did not have any fur-
Volume 82 Number 2 August, 1981
Waterston anastomosis for tetralogy of Fallot
179
Table VI. Waterston shunt in patients with tetralogy of Fallot (1966-1979) Nonfatal hospital complications
No.
Heart failure Respiratory infection Wound infection Enteritis
10* 7 5 2
Good
Fair Poor
• In one case surgical revision of the shunt was carried out.
Fig. 2. Status of the patients who received a Waterston shunt at the follow-up visit before any further operation.
Table VII. Waterston shunt in patients with tetralogy of Fallot (1966-1979) Events after discharge from the hospital
No.
Hemiparesis Femoral artery thrombosis Brain abscess Meningitis
4 1*
It It
• Amputation of the leg. t Death.
ther surgical procedure (mean follow-up, 2.3 ± 1.25 years); 90 patients underwent secondary repair on an elective basis (mean interval between the Waterston shunt and the repair, 3.4 ± 1.48 years); 10 patients (seven for persistent cyanosis and three for some degree of heart failure) underwent correction before reaching the elective age (mean interval between the shunt and the repair, 0.9 ± 0.71); and 10 others required further palliation for persistent symptoms (mean interval between the initial Waterston shunt and the second palliative operation, 1.5 ± 1.29 years). The clinical status at the time of the last follow-up visit before any further surgical procedure was categorized as good in 74%, fair in 17%, and poor in 9% of the patients who survived a Waterston shunt (Fig. 2). The events which occurred after discharge from the hospital are listed in Table VII; two of them (a cerebral abscess and meningitis) were fatal. By actuarial methods, therefore, 97.7% (CL = 95.2% to 99.3%) of hospital survivors were alive and 95.8% (CL = 93.3% to 97.4%) were event-free at and beyond 3 years postoperatively (longest follow-up 7.3 years). Survival and event-free actuarial curves are shown in Fig. 3.
Catheterization and angiocardiography Eighty-six of the patients who survived the Waterston shunt had cardiac catheterization and angiocardiograms in preparation for secondary repair. The mean interval between the palliative procedure and the catheterization was 2.9 ± 1.38 years. Only one patient, who surprisingly had had the Waterston shunt only 2 years earlier, was found to have pulmonary hy-
pertension with pulmonary vascular disease and was considered inoperable. In the remaining patients the mean pressure in the main pulmonary artery was 15 ± 4.9 mm Hg. In four children (about 5% of the 86 who were catheterized), pulmonary atresia developed in the interval between the shunt and the prerepair study. The angiocardiographic studies showed some kinking at the site of the anastomosis in 38 patients (44%); in 14 others (16%) only the right pulmonary artery was visualized by the aortogram, there being no retrograde flow to visualize the proximal right pulmonary artery or main and left arteries. In a previous study, we" have demonstrated and quantitated the growth of the pulmonary arteries and particularly of the pulmonary anulus after the Waterston anastomosis.
Discussion Although we" occasionally have performed primary repair of tetralogy of Fallot in children in the first year of life, a palliative operation has always been the treatment of choice in this age group. In particular, the Waterston shunt has been used preferentially, while the Blalock- Taussig anastomosis has been performed less commonly, generally in patients older than 6 months. This attitude gave us the opportunity of studying a large number of patients who received a Waterston shunt as initial palliation of tetralogy of Fallot. Our hospital mortality compares favorably with those of other series, to- t2 and it is similar to that recently reported by Alvarez-Diaz and associates. 13 The age and the weight of the patients, as well as the preoperative condition, do not appear to influence significantly the operative mortality. Analysis of our results clearly indicates that the size of the shunt stoma is the crucial point of the Waterston operation. Despite an accurate calibration of the aortotomy according to the body weight, a number of patients had too small or too large a shunt possibly because of an inadequate technique of performing the
The Journal of Thoracic and Cardiovascular Surgery
1 80 Parenzan et at.
1.00 0.99 P R 0 P 0 R T I 0 N
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YEARS AFTER THE WATERSTON SHUNT Fig. 3. Survival (dotted line) and event-free (continuous line) actuarial curves computed for the 215 patients who were discharged from the hospital after a Waterston shunt. Confidence limits are indicated by the vertical bars.
anastomosis. This error was largely responsible for the hospital mortality and morbidity. Furthermore, some of the patients who survived either required correction earlier than planned or required a further palliation, again for a shunt that was either too small or too large. We have learned to evaluate the shunt on the operating table by palpating the thrill on the right pulmonary artery after the completion of the anastomosis. If the shunt appears to be too small, we redo the anastomosis; if it is too large, we reduce the stoma in the manner already described. 14 The events which occurred in our patients after discharge from the hospital are not very uncommon in patients with persistent right-to-left shunts across the ventricular septum and have also been reported following a Blalock-Taussig shunt. 5 Pulmonary vascular obstructive disease is commonly considered a risk associated with the Waterston shunt. 15 However, our hemodynamic studies in a large number of patients reveal that pulmonary hypertension with a severe degree of pulmonary vascular disease is extremely rare after a Waterston shunt. "Kinking" of the right pulmonary artery at the site of the anastomosis is another common criticism of the Waterston operation. 16 In a recent review of our experience with repair of tetralogy of Fallot after a Waterston operation, we" found that the patients who required patch-graft enlargement of the right pulmonary artery because of severe kinking and stenosis at the site of the anastomosis had a postrepair right ventricular- to-left ventricular pressure ratio similar to that of the rest of the patients.
Growth of the pulmonary anulus, which is more pronounced after the Waterston than after the BlalockTaussig anastomosis," is an argument in favor of the Waterston shunt, since the use of a transanular patch in repair of tetralogy of Fallot has been associated with a higher hospital mortality. r. 6 The short operating time and lack of need for interruption of the subclavian artery are other advantages of the Waterston over the Blalock-Taussig shunt. All these considerations support our preferential use of the Waterston shunt as initial palliation for tetralogy of Fallot.
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REFERENCES Kirklin JW, Blackstone EH, Pacifico AD, Brown RH, Bargeron LH Jr: Routine primary repair versus 2-stage repair of tetralogy of Fallot. Circulation 60:373-386, 1979 Stephenson LW, Friedman S, Edmunds LH Jr: Staged surgical management of tetralogy of Fallot in infants. Circulation 58:837-841, 1978 Chopra PS, Levy JM, Dacumos GC Jr, Berkoff HA, Loring LL, Kahn DR: The Blalock-Taussig operation. The procedure of choice in hypoxic infants with tetralogy of Fallot. Ann Thorac Surg 22:235-238, 1976 Arciniegas E: Discussion of Castaneda AR, Freed MD, Williams RG, Norwood WI: Repair of tetralogy of Fallot in infancy. J THoRAc CARDIOVASC SURG 74:372-381, 1977 Taussig HB, Crawford H, Pelargonio S, Zacharioudakis S: Ten to thirteen year follow-up on patients after a Blalock-Taussig operation. Circulation 25:630-634, 1962 Alfieri 0, Locatelli G, Bianchi T, Vanini V, Parenzan L:
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Repair of tetralogy of Fallot after Waterston anastomosis. J THORAC CARDIOVASC SURG 77:826-831, 1979 Berkson J, Gage RP: Calculation of survival rates for cancer. Mayo Clin Proc 25:270-286, 1950 Alfieri 0, Blackstone EH, Parenzan L: Growth of the pulmonary anulus and pulmonary arteries after the Waterston anastomosis. J THORAC CARDIOVASC SURG 78:440-444, 1979 Parenzan L, Alfieri 0: Correction of tetralogy of Fallot in the first year of life, Paediatric Cardiology, RH Anderson, EA Shinebourne, eds., London, 1978, Churchill Livingstone, p 289 Bernhard WF, Jones JE, Friedberg DZ, Litwin SB: Ascending aorta-right pulmonary artery shunt in infants and older patients with certain types of cyanotic congenital heart disease. Circulation 43:580-584, 1971 Barratt-Boyes BG: Primary definitive intracardiac operation in infants: Tetralogy of Fallot, Advances in Cardiovascular Surgery, JW Kirklin, ed., New York, 1973, Grune & Stratton, Inc., p 156
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12 Idriss FS, Cavallo CA, Nikaidoh H, Paul MH, Koopot R, Muster AJ: Ascending aorta-right pulmonary artery shunt. J Thorac Cardiovasc Surg 71:49-57, 1976 13 Alvarez-Diaz F, Sanz E, Sanchez PA, Cordovilla G, Celemind D, Moreno F, Borches D, Gutierrez JR: Fallot's tetralogy: Palliation and Repair With a Previous Shunt, Paediatric Cardiology, RH Anderson, EA Shinebourne, eds., London, 1978, Churchill Livingstone, p 273 14 Alfieri 0, Bianchi T, Tiraboschi R, Parenzan L: Surgical revision of Waterstons anastomosis for intractable heart failure. Surg Italy 6:19-24, 1976 15 Newfeld EA, Wadman JD, Paul MH, Muster AJ, Cole RB, Idriss F, Ricker W: Pulmonary vascular disease after systemic-pulmonary arterial shunt operations. Am J Cardiol 39:715-720, 1977 16 Gay WA Jr, Ebert PA: Aorta to right pulmonary artery anastomosis causing obstruction of the right pulmonary artery. Management during correction of tetralogy of Fallot. Ann Thorac Surg 16:402-410, 1973