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Postoperative Long-Term Results in Total Correction of Tetralogy of Fallot: Hemodynamics and Cardiac Function
Postoperative Long-Term Results in Total Correction of Tekalogy of Fdot: Hemodynamics and Cardiac Function Hidetaku Oku, M.D., Hitoshi Shirotani, M.D., Akio Sunakawa, M.D., and Tatsuo Yokoyama, M.D. ABSTRACT Late results were assessed in 63 patients who underwent complete repair of tetralogy of Fallot. These patients were divided into four groups. Group I-A included 13 who had a transannular patch with a monocusp, and whose cross-sectional area index (CSAI) was less than 2.5 cm2/m2;group I-B included 11 with the patch and with a CSAI greater than 2.5 cmz/m2.Group I1 included 27 patients who underwent pulmonary valvotomy. Group 111 included 9 who had not undergone valvotomy and 3 who had undergone pulmonary valve replacement. Late death occurred in 1 patient, and reoperation was done on 3. Mild pulmonary stenosis (PS) was present in 73%, moderate PS in 17%, and severe PS in 10% of the patients. A significant pulmonary regurgitation (PR) of grade 3 or 4 was present in 33% of the patients in group I-A, and in 87% of group IB, 17% of group 11, and 0% of group 111. Right ventricular end-diastolic volume was normal in patients with a PR of grade 2 or less, and it was higher in patients who had a significant PR. The ejection fraction was generally decreased, regardless of the grade of PR. Left ventricular function was normal in those with a PR of grade 3 or less and was impaired in those with a PR of grade 4. Thus, late postoperative hemodynamics and ventricular function were excellent in patients with a mild PS and a PR of grade 2 or less, and it was poor in those with a moderate PS and a significant PR. To prevent significant PR, enforced blunt enlargement of the pulmonary annulus should be avoided, and when a transannular patch is used, the CSAI should be 1.75 to 2.5 cm2/mZ.Coaptation between the autopulmonary cusp and the cusp attached to the patch should be done. Surgical results for total correction of tetralogy of Fallot have improved remarkably, thanks to improvements in cardiac surgery and the establishment of criteria for enlargement of the right ventricular outflow tract (RVOT) [l-41. Earlier, when we reported these criteria for RVOT enlargement to relieve RVOT obstruction, we based them on early postoperative hemodynamics as well as surgical results, and emphasized that the cross-sectional area index (CSAI) of the pulmonary annulus should
From the Department of Cardiovascular Surgery, Kinki University School of Medicine, Osaka, Japan. Accepted for publication July 9, 1985. Address reprint requests to Dr. Oku, Department of Cardiovascular Surgery, Kinki University School of Medicine, 380 Nishiyama Sayamacho Minamikawachi-gun, Osaka 589, Japan.
413 Ann Thorac Surg 41:413-418, April 1986
range from 1.75 to 2.5 cm2/m2when a transannular patch is used [2,5]. The present study was carried out to elucidate the relationship between the method and degree of relief of the RVOT obstruction and the postoperative long-term hemodynamics as well as cardiac functions.
Material and Methods Our patients were 63 Japanese citizens who had consecutively undergone complete repair of tetralogy of Fallot. Of these 63, 53 underwent postoperative cardiac catheterization and angiocardiography one to three times. The average age at repair was 3.1 years (range, 6 months to 25 years). Thirty-eight (60%)of these patients were 2 years of age or younger, 15 (24%) were 3 or 4 years of age, and 10 (16%) were older than 4 years. The follow-up period was from 1 to 16 years (average, 5.3 years). The degree of relief of the RVOT obstruction was expressed as the CSAI of the RVOT, or the pulmonary annulus after enlargement. The CSAI was obtained by the following equation: CSAI = r(d/2)’/BSA (in cm’/m’), where d is the diameter of the pulmonary annulus after enlargement at operation and BSA is the body surface area (m’). This formula yields the postoperative size of the RVOT or pulmonary annulus per unit of BSA. RVOT was enlarged so as to obtain a CSAI greater than 1.75 cm2/m2.For this, a transannular patch with a single cusp was inserted, as required. The residual or recurrent pulmonary stenosis (PS) at rest was classified into three grades: mild PS (systolic pressure gradient between right ventricle (RV) and pulmonary artery (PA) <23 mm Hg); moderate PS (pressure gradient ranging from 23 to 40 mm Hg); and severe PS (pressure gradient 40 mm Hg or more). The grade of the postoperative pulmonary regurgitation (PR) was expressed as the degree of regurgitation of contrast medium refluxing into the right ventricle in the pulmonary arteriogram (Fig 1).Using a side-hole catheter (National Institutes of Health, No. 6), contrast medium of 1 to 1.5 mVkg was injected at the rate of 14 mVs into the main PA. At this time, no consideration was given to expand the area and light and shade of the contrast medium. Biplane cineangiocardiograms were used to assess heart volume. The left and right ventricular volumes were calculated by the area-length method and by the Simpson rule, respectively. All volume estimations were normalized to BSA, and the volumes were expressed as a percentage of normal. We used our own equations to derive normal values for the right ventricular enddiastolic volume (RVEDV), the left ventricular enddiastolic volume (LVEDV), the right ventricular ejection
414 The Annals of Thoracic Surgery Vol 41 No 4 April 1986
loci when valvular stenosis was also present. Atrial septal defect was closed directly or with a patch in 6 patients, and patent foramen ovale was also closed in 32. CSAI values were greater than 1.75 cm2/m2in all. As a cusp mounted on the transannular patch, the autopericardium was used in 12 patients, the Rygg patch in 5, the Gore-Tex sheet in 2, and the Xenomedica patch in 2. In 3 patients, one leaflet of the original pulmonary valve was incised along the valve ring, and the incised edge of the leaflet was then attached to the inserted outflow patch.
Results
Fig 1 . Grade of pulmonary regurgitation. The right ventricle was vertically separated into four equal parts from the pulmonary annulus to the apex in a lateral projection of pulmona y arteriography, and pulmonary regurgitation was classified into grades (Gl, G2, G3, and G4), from least to greatest regurgitation.
fraction (RVEF), and the left ventricular ejection fraction (LVEF). Thus, RVEDV = 69.2(BSA)'.34, LVEDV = 70.6(BSA)'.31, RVEF = 0.51-0.70, and LVEF = 0.550.75. Sixty-three patients were separated into groups according to method and degree of relief of RVOT obstruction. Group I included 24 in whom a transannular patch with a single cusp was placed. Group I was further subdivided into two subgroups according to CSAI; i.e., group I-A had 13 patients with a CSAI from 1.75 to 2.5 cm2/m2 and group I-B had 11 patients with a CSAI greater than 2.5 cm2/m2.Group I1 included 27 undergoing pulmonary valvotomy, with or without a localized patch on the main PA, on the RVOT, or on both. Group 111 included 12 patients, of whom 9 underwent no valvotomy and 3 with absent pulmonary valve had pulmonary valve replacement (PVR). Of these 63 patients, 57 underwent surgery with hypothermia; the perfusate temperature was between 20 and 25°C. For 6 patients, deep hypothermia combined with circulatory arrest and limited cardiopulmonary bypass was used. Intermittent aortic cross-clamping (10 to 15 minutes) was used for the initial 28 patients. For the next 31 patients, a single period of cardiac arrest induced with Young's solution and maintained with cold-blood cardioplegia was used. The previously performed arteriopulmonary shunts in 2 patients and patent ductus arteriosus in 3 patients were ligated at the initiation of the cardiopulmonary bypass. In all patients, ventricular septa1 defects were closed with a patch by means of horizontal interrupted mattress sutures. Infundibular muscular resection was carried out to various degrees in all patients, and commissurotomy was performed at two
Late death resulting from bacterial encephalomeningitis occurred in 1 patient. Three patients underwent reoperation. Two patients, 1 of whom had initially had a transannular patch, underwent PVR for PR. A transannular patching for restenosis was performed in 1 patient. A trivial leakage at the ventricular level was detected on left ventriculography in 3 patients, but no subsequent operative procedures were required. Of 49 patients undergoing pulmonary arteriography in the early and late postoperative periods, 6 were free of PR, 28 had a PR of grades 1 or 2, and 15 had a PR of grades 3 or 4. In 3 patients undergoing PVR, PR was absent on auscultation (Table 1). A significant PR of grade 3 or 4 was present in 33% of the patients in group I-A, 87% of group I-B, 17% of group 11, and 0% of group 111. Thus, significant PR was frequent in patients who had a transannular patch and a CSAI greater than 2.5 cm2/m2.In the group I1 patients who had a valvotomy, a PR of grades 3 or 4 was present in 4 patients undergoing enforced enlargement of the pulmonary annulus by Hegar dilator. The grade of PR changed in only 2 patients. In l patient, PR that had been of grade 3 in the early postoperative period was improved to grade 2, and it elicited recurrent PS in the late postoperative period. In the other, PR deteriorated from grade 1 in the early postoperative period to grade 2 in the late postoperative period. Of 30 patients in whom the late postoperative systolic pressure gradient between RV and PA (RV-PA) was obtained, 3 had severe PS, 5 had moderate PS, and 22 had mild PS. Incidence of mild PS was 71% in group I-A, 60% in group I-B, 86% in group 11, and 67% in group 111. Figure 2 shows the relationship between the ratio of Table 1 . Grade of Pulmonary Regurgitation No. of Patients with PR of Grade: Group
0
1
2
3
4
I-A
0 0 0
1 0 10
4 4 3
0
9"
0
7 1 9 0
0
0
1-8
I1 111
3 1
'Includes 3 patients undergoing PVR;49 underwent pulmonary arteriography.
415 Oku, Shirotani, Sunakawa, et al: Correction of Tetralogy of Fallot
0.301
0.20'
4&&
I I
A
10
1
20
II I
1
1
30
40
50
60
70
RV-PA Systollc Pressure Gradient (mmHg)
Fig 2 . Znfluence of pulmonary stenosis and regurgitation on right ventricular pressure in the late postoperative period. Vertical axis indicates the right ventricular-to-aortic pressure ratio (RV/Ao). Horizontal axis indicates the right ventricular-to-pulmonary artery (RVPA) systolic pressure gradient. Numbers inside symbols refer to grade of pulmonary regurgitation.
the right ventricular-to-aortic systolic pressure (RVIAo) and the degree of PS and PR in the late postoperative period. In 30 patients, none had distal pulmonary hypertension and only 1 had a branch stenosis of the PA. Twenty-two patients had mild PS. In 21, the RV/Ao ratio was 0.50 or less, regardless of the grade of PR; the one exception was a patient with a PR of grade 4. Five patients had moderate PS. The pressure ratio was greater than 0.60 in 2 of them whose PR was of grade 3 or more, whereas the pressure ratio was less than 0.50 in the 3 patients with a PR of grade 1 or less. Thus, a PR of grade 3 or more, particularly when combined with a moderate PS, was considered a factor contributing to RV hypertension. In all 3 patients with severe PS, the PR was of grade 2. However, RV hypertension with an RV/Ao ratio of greater than 0.50 was present in 29% (Y7) of group IA, 60% (3/5) of group I-B, 7% (1/15) of group 11, and 0% (013) of group 111. There was no significant difference between the incidence in group I-A and that in group IB. Accordingly, a wider enlargement of the pulmonary annulus was not always attributed to a decrease in RV pressure in the late postoperative period when a transannular patch was used. Of 30 patients in whom the PA/Ao (pulmonary arteryto-aortic systolic) pressure ratio was measured, 4 had a pressure ratio greater than 0.40, and 26 had one less than 0.40. Of the 4 patients with a PAIAo greater than 0.40, 3 patients had a PR of grades 3 or 4, and 1 patient had a PR of grade 2 and main PA hypertension resulting from branch stenosis. Therefore, a significant PR was prone to pulmonary hypertension.
The late postoperative right ventricular end-diastolic pressure (RVEDP) was 8 mm Hg or less in all 18 patients with mild PS and in 3 patients with severe PS, regardless of the grade of PR. Five patients had a moderate PS; RVEDP was 11 mm Hg or greater in 2 of these whose PR was severe, and it was 8 mm Hg or less in all 3 patients who had a PR of grade 2 or less. However, the late postoperative LVEDP was within normal limits in all patients and averaged 7.5 mm Hg (range, 6 to 10 mm Hg). Thus, the hemodynamics of the right heart were excellent in patients with a mild PS and with a PR of grade 2 or less, and were poorest in those with a moderate PS and with a PR of grade 3 or more. The late postoperative LV hemodynamics were normal, regardless of the grade of PS or PR. Figure 3 shows the relationship between the grade of PR and the RVEDV in the early and late postoperative periods. The early postoperative RVEDV was 102 t 13% in patients with a PR of grade 0, 112 2 15% in a PR of grade 1,115 2 18% in a PR of grade 2,106 2 6% in a PR of grade 3, and 134 2 11%in a PR of grade 4. There was no significant difference among these values, though the average value in a PR of grade 4 was slightly greater than the others. In the late postoperative period, RVEDV was 139 2 13% in a PR of grade 0, 116 t 22% in a PR of grade 1,122 2 23%in a PR of grade 2,170 2 23%in a PR of grade 3, and 203 33% in a PR of grade 4. There was a significant difference between the values in three groups with a PR of grade 2 or less and those in two groups with a PR of grade 3 or more (P < 0.001). Therefore, in the late postoperative period, a PR of grade 2 or less did not enlarge RVEDV and a PR of grade 3 or more did enlarge RVEDV. Particularly, in 2 of 4 patients with a PR of grade 4, mild tricuspid regurgitation (TR) absent in the early postoperative period was detected in the late postoperative period.
*
PR
Fig 3 . Relationship between early and late postoperative right ventricular end-diastolic volume (RVEDV) and grade of pulmona ry regurgitation. Open symbols indicate the early postoperative RVEDVs. Closed symbols show late postoperative values.
416 The Annals of Thoracic Surgery Vol 41 No 4 April 1986
Table 2 . Postoperative Cardiothoracic Ratioa Postop CTR for Patients with PR of Grade: Years Postop 1 2-3 24
0
1
2
3
4
0.56 f 0.04 (N = 5) 0.53 f 0.02 (N = 3) 0.52 f 0.02 (N = 4)
0.58 f 0.04 (N = 7) 0.58 f 0.03 (N = 6) 0.53 2 0.05 (N = 7)
0.59 f 0.03 (N = 13) 0.58 ? 0.04 (N = 12) 0.54 ? 0.05
0.60 ? 0.04 (N = 10) 0.59 f 0.03 (N = 9) 0.57 ? 0.01
0.61 f 0.05 (N = 4) 0.60 ? 0.03 (N = 3) 0.60 ? 0.00
(N = 6)
(N = 2)
(N = 10)
"Numbers indicate means 2 standard deviation; N = number of patients.
PR
=
pulmonary regurgitation; CTR
=
cardiothoracic ratio.
Average value of the late postoperative RVEF was 0.48 0.03 in a PR of grade 0, 0.50 ? 0.07 in a PR of grade 1, 0.48 & 0.07 in a PR of grade 2, 0.47 t 0.04 in a PR of grade 3, and 0.47 f 0.09 in a PR of grade 4. Although RVEDV values were all less than normal, regardless of the grade of PR, RVEF was normal in 39% of the patients with a PR of grade 2 or less and only in 18% in those with a PR of grade 3 or more. Late postoperative LVEDV was 126 -+ 12% in a PR of grade 0,107 f 10% in a PR of grade 1,108 f 19%in a PR of grade 2,128 f 22% in a PR of grade 3, and 153 t 32% in a PR of grade 4. LVEF was 0.58 f 0.08, 0.56 f 0.03, 0.58 ? 0.04, 0.56 t 0.04, and 0.53 t 0.02 in a PR of grade 0 to grade 4. Thus, the average values of LVEDV and LVEF were normal or near normal in patients with a PR of grade 3 or less. In patients with a PR of grade 4, the LVEDV was mildly increased and the LVEF was slightly depressed. The postoperative cardiothoracic ratio (CTR) is shown in Table 2. The mean CTR was greater than 0.55 in all patients, regardless of the grade of PR at 1 year after repair. Two to 3 years postoperatively, the average value of CTR was normal only in patients with a PR of grade 0 and exceeded normal in those with a PR of grade 1 or more. Four to 13 years after surgery, the ratio was less than 0.55 in patients with a PR of grade 2 or less and exceeded normal in those with a PR of grade 3 or more. CTR did not relate to the degree of PS. 2
Comment Factors affecting late results after complete repair of tetralogy of Fallot include PS, PR, complete right bundle branch block, right ventriculotomy, age at operation, etc. [6-111. Of these factors, PS and PR are the most important, and the diminution of PS and PR remains the major problem. We assessed postoperative long-term results with particular attention to the relationship between PS and PR and the late hemodynamics and cardiac function after repair. As to PS which is expressed as the RV-PA pressure gradient, we reported that the early postoperative RVPA pressure gradient is mainly regulated by a CSAI, and that the wider the annulus, the lower the RV-PA pressure gradient [l, 2, 51. In the present study, the late
postoperative PS did not relate to CSAI. Particularly in patients with a transannular patch, the RV-PA pressure gradient and RV/Ao pressure ratio were both greater in group I-B with a CSAI greater than 2.5 cm2/m2than in group I-A with a CSAI of less than 2.5 cm2/m2,in contrast to the early postoperative results. This is in part related to the fact that the PR was more severe in group I-B than in group I-A, and in part to the fact that postoperative growth of the pulmonary annulus was poorer because the ratio of the widths of the autopulmonary annulus to the inserted patch was greater in group 1-8. We wish to emphasize that wider enlargement of the pulmonary annulus does not always result in a milder PS in the late postoperative period, and that a procedure which leads to excellent development of the pulmonary annulus after repair should be chosen even when a transannular patch is used. In this series, in mild and moderate PS with an RV-PA pressure gradient of less than 40 mm Hg, RVEDP, RV/ Ao, and PA/Ao pressure ratio, CTR, LVEDV, LVEF, and RVEDV were all within normal limits when a significant PR of grade 3 or more was not combined. Even in patients with a severe PS and an RV-PA pressure gradient of greater than 40 mm Hg, RVEDV, RVEDP, CTR, and LV functions were normal, though RV hypertension was present. Thus, residual RVOT obstruction can be tolerated well, if isolated [12]. However, in repair of TF, PR is elicited with high frequency [13], although the degree varies. In our study, PR was detected in all who underwent valvotomy or transannular patching. A severe PR of grade 4 was detected in patients undergoing enforced enlargement of the pulmonary annulus by Hegar dilator after valvotomy, and in those with a transannular patch and a CSAI greater than 2.5 cm2/m2. With regard to PR, Ellison and colleagues [14] found in experimental animals that the isolated PR is well tolerated over a number of years. Calder and colleagues [lo] found that PR was well tolerated clinically and hemodynamically, unless there was distal pulmonary artery or branch stenosis, whereas Shaher and co-workers [15] reported that 4 of 9 patients with PVR for PR had an isolated PR. Chiariello and associates [16] stated that PR is preferable to PS, and Hawe and co-authors [17] stated
417 Oku, Shirotani, Sunakawa, et al: Correction of Tetralogy of Fallot
that prognosis is better if PR is combined with a mild PS. In our evaluation, a PR of grade 2 or less did not influence the late hemodynamics, and a significant PR of grade 3 or more elevated the RV-PA pressure gradient [18]. Furthermore, when a severe PR was combined with a moderate PS, RVEDP was also above normal. Regarding the influence of PR on the RV function, Bove and colleagues [18] showed that the RVEF was markedly decreased in patients with PR, as compared with that in patients without PR. Generally in the present study, the average values of RVEF were decreased, regardless of the degree of PR and PS, though RVEF was normal in only one-third of the patients. The incidence of depressed RVEF is higher in patients with a significant PR than in those with a PR of grade 2 or less. However, many factors determine RV volume, including PR, RV dysfunction, size of the patch, and degree of muscular resection. Thus, the RV volume is not influenced only by PR. But the RVEDV was normal or near normal in patients with a PR of grade 2 or less and increased in those with a PR of grade 3 or more. In particular, 4 patients with a PR of grade 4 had a remarkably increased RVEDV (average value, 203%), and 2 patients had a slight TR. From these findings, we cannot help considering that a severe PR impaired RV function. Between PR and RV dilatation is a vicious circle in which the PR increases RV dilatation and the RV dilatation deteriorates PR [15]. There is a similar vicious circle for TR and RV dilatation [15]. In our 2 patients, TR was not evident in the early postoperative cardiac catheterization; therefore, it was considered to be caused by RV dilatation. The functional status of the LV in postrepair patients has been widely discussed but remains controversial. Rocchini and co-workers [191 reported normal cardiac output, LVEDP, LVEDV, and LVEF after successful repair, whereas Jarmakani and colleagues [20] noted, in cineangiographic studies, a depressed LVEF, in both preoperative and postoperative patients. Bove and coworkers [18], using radionuclide ventriculography, stated that the LVEF was considerably more normal in patients without PR than in those with PR. In our series, the late postoperative LVEDV and LVEF were normal as long as the PR was of grade 3 or less. The LVEDV was increased and the LVEF was decreased when the PR was of grade 4. Wessel and associates [12] stated that exercise tolerance strongly decreases when PR coexists with PS. Their results corresponded with our finding that postoperative late hemodynamics and cardiac function were poorest in patients with a PR of grade 3 or more and a moderate PS. CTR was enlarged in patients with PR [18]. In our study, the CTR was above normal 1 year after surgery, regardless of the grade of PR. CTR was restored to normal in patients with a PR of grade 2 or less 4 years after surgical repair, but in patients with a PR of grade 3 or more it was still higher than normal even 4 years after repair. As mentioned previously, opinions vary with regard to the influence of PR on postoperative hemodynamics
and cardiac function. This is considered to be due in part to differences in estimation of the PR, and in part to the lack of an accurate and convenient method to measure regurgitant volume. We classified PR into four grades, according to reflux of the contrast medium into RV in the lateral projection of the pulmonary arteriography. Although our grading of PR does not always reflect a regurgitant volume accurately and is only an approximation because the expanding area and light and shade of the contrast medium are not taken into consideration, the grades do coincide with clinical findings and with hemodynamic and volumetric data. In our classification, a PR of grade 2 or less was irrelevant and harmless, and a PR of grade 3 or more was considered to be hemodynamically and functionally significant, and it impaired the late postoperative hemodynamics and cardiac functions. In particular, a PR of grade 4 depressed LV function. Thus, to maintain excellent postoperative hemodynamics and cardiac function, it is imperative to obtain a PR of grade 2 or less. To prevent severe PR, Kawashima and colleagues [21] used several fine procedures in reconstruction of RVOT and obtained excellent results. In our conventional procedure using a transannular patch, a CSAI of less than 2.5 cm2/m2and a more precise coaptation between original pulmonary cusp and the cusp mounted on the patch could avoid a PR of grade 3 or more. An enforced enlargement using a dilator should not be done after valvotomy.
References 1. Oku H: Operative results and postoperative hemodynamic results in total correction of tetralogy of Fallot. Nippon Geka Hokan 45937, 1976 2. Oku H, Shirotani H, Yokoyama T, et al: Postoperative size of the right ventricular outflow tract and optimal age in complete repair of tetralogy of Fallot. Ann Thorac Surg 25:322, 1978 3. Naito Y, Fujita T, Manabe H, Kawashima Y: The criteria for reconstruction of right ventricular outflow tract in total correction of tetralogy of Fallot. J Thorac Cardiovasc Surg 80574, 1980 4. Blackstone EH, Kirklin JW, Bertranou EG, et al: Preoperative prediction from cineangiograms of postrepair right ventricular pressure in tetralogy of Fallot. J Thorac Cardiovasc Surg 7 8 9 2 , 1979 5. Oku H, Shirotani H, Yokoyama T, et al: Right ventricular outflow tract prosthesis in total correction of tetralogy of Fallot. Circulation 62:604, 1980 6. Borow KM, Green LH, Castaneda AR, Keane JF.: Left ventricular function after repair of tetralogy of Fallot and its relationship to age at surgery. Circulation 61:1150, 1980 7. Katz NM, Blackstone EH, Kirklin JW, et al: Late survival and symptoms after repair of tetralogy of Fallot. Circulation 65:403, 1982 8. Yasui H, Takeda Y, Yamauchi S, et al: The deleterious effects of surgically induced complete right bundle branch block on long-term follow-up results of closure of ventricular septa1 defect. J Thorac Cardiovasc Surg 74210, 1977 9. Sanger PW, Robicsek F, Taylor FH, Davis SC: A method of preventing myocardial damage by using a modified ventriculotomy incision. Ann Surg 155:874, 1962
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10. Calder AL, Barratt-Boyes BG, Brandt PWT, Neutze JM: Postoperative evaluation of patients with tetralogy of Fallot repaired in infancy. J Thorac Cardiovasc Surg 77704, 1979 11. Bristow JD, Kloster FE, Lees MH, et al: Serial cardiac catheterizations and exercise hemodynamics after correction of tetralogy of Fallot. Circulation 41:1057, 1970 12. Wessel HU, Cunningham WJ, Paul MH, et al: Exercise performance in tetralogy of Fallot after intracardiac repair. J Thorac Cardiovasc Surg 80:582, 1980 13. Arciniegas E, Farooki ZQ, Hakimi M, et al: Early and late results of total correction of tetralogy of Fallot. J Thorac Cardiovasc Surg 80:770, 1980 14. Ellison RG, Brown WJ Jr, Yeh TJ, Hamilton WF: Surgical significance of acute and chronic pulmonary valvular insufficiency. J Thorac Cardiovasc Surg 60549, 1970 15. Shaher RM, Foster E, Farina M, et al: Right heart reconstruction following repair of tetralogy of Fallot. Ann Thorac Surg 35:421, 1983 16. Chiariello L, Meyer J, Wukasch DC, et al: Intracardiac re-
17. 18.
19. 20.
21.
pair of tetralogy of Fallot. J Thorac Cardiovasc Surg 70:529, 1975 Hawe A, Rastelli GC, Ritter DG, et al: Management of the right ventricular outflow tract in severe tetralogy of Fallot. J Thorac Cardiovasc Surg 60:131, 142, 1970 Bove EL, Byrum CJ, Thomas FD, et al: The influence of pulmonary insufficiency on ventricular function following repair of tetralogy of Fallot. J Thorac Cardiovasc Surg 85:691, 1983 Rocchini AP, Keane JF, Freed MD, et al: Left ventricular function following attempted surgical repair of tetralogy of Fallot. Circulation 57:798, 1978 Jarmakani JMM, Graham TP Jr, Canent RV Jr, Jewett PH: Left heart function in children with tetralogy of Fallot before and after palliative and corrective surgery. Circulation 46:478, 1972 Kawashima Y, Kitamura S, Nakano 5, Yagihara T: Corrective surgery for tetralogy of Fallot without or with minimal right ventriculotomy and with repair of the pulmonary valve. Circulation 64:Suppl 11:11, 1981
Notice from the American Board of Thoracic Surgery The Part I (written) examination will be held at the Amfac Hotel, Dallas/Fort Worth Airport, Dallas, TX, in February, 1987. The closing date for registration is August 1, 1986. To be admissible for the Part I1 (oral) examination, a candidate must have successfully completed the Part I (written) examination.
A candidate applying for admission to the certifying examination must fulfill all the requirements of the Board in force at the time the application is received. Please address all communications to the American Board of Thoracic Surgery, 14640 E Seven Mile Rd, Detroit, MI 48205.
From the Department of Cardiovascular Surgery, Kinki University School of Medicine, Osaka, Japan. Accepted for publication July 9, 1985. Address reprint requests to Dr. Oku, Department of Cardiovascular Surgery, Kinki University School of Medicine, 380 Nishiyama Sayamacho Minamikawachi-gun, Osaka 589, Japan.
413 Ann Thorac Surg 41:413-418, April 1986
range from 1.75 to 2.5 cm2/m2when a transannular patch is used [2,5]. The present study was carried out to elucidate the relationship between the method and degree of relief of the RVOT obstruction and the postoperative long-term hemodynamics as well as cardiac functions.
Material and Methods Our patients were 63 Japanese citizens who had consecutively undergone complete repair of tetralogy of Fallot. Of these 63, 53 underwent postoperative cardiac catheterization and angiocardiography one to three times. The average age at repair was 3.1 years (range, 6 months to 25 years). Thirty-eight (60%)of these patients were 2 years of age or younger, 15 (24%) were 3 or 4 years of age, and 10 (16%) were older than 4 years. The follow-up period was from 1 to 16 years (average, 5.3 years). The degree of relief of the RVOT obstruction was expressed as the CSAI of the RVOT, or the pulmonary annulus after enlargement. The CSAI was obtained by the following equation: CSAI = r(d/2)’/BSA (in cm’/m’), where d is the diameter of the pulmonary annulus after enlargement at operation and BSA is the body surface area (m’). This formula yields the postoperative size of the RVOT or pulmonary annulus per unit of BSA. RVOT was enlarged so as to obtain a CSAI greater than 1.75 cm2/m2.For this, a transannular patch with a single cusp was inserted, as required. The residual or recurrent pulmonary stenosis (PS) at rest was classified into three grades: mild PS (systolic pressure gradient between right ventricle (RV) and pulmonary artery (PA) <23 mm Hg); moderate PS (pressure gradient ranging from 23 to 40 mm Hg); and severe PS (pressure gradient 40 mm Hg or more). The grade of the postoperative pulmonary regurgitation (PR) was expressed as the degree of regurgitation of contrast medium refluxing into the right ventricle in the pulmonary arteriogram (Fig 1).Using a side-hole catheter (National Institutes of Health, No. 6), contrast medium of 1 to 1.5 mVkg was injected at the rate of 14 mVs into the main PA. At this time, no consideration was given to expand the area and light and shade of the contrast medium. Biplane cineangiocardiograms were used to assess heart volume. The left and right ventricular volumes were calculated by the area-length method and by the Simpson rule, respectively. All volume estimations were normalized to BSA, and the volumes were expressed as a percentage of normal. We used our own equations to derive normal values for the right ventricular enddiastolic volume (RVEDV), the left ventricular enddiastolic volume (LVEDV), the right ventricular ejection
414 The Annals of Thoracic Surgery Vol 41 No 4 April 1986
loci when valvular stenosis was also present. Atrial septal defect was closed directly or with a patch in 6 patients, and patent foramen ovale was also closed in 32. CSAI values were greater than 1.75 cm2/m2in all. As a cusp mounted on the transannular patch, the autopericardium was used in 12 patients, the Rygg patch in 5, the Gore-Tex sheet in 2, and the Xenomedica patch in 2. In 3 patients, one leaflet of the original pulmonary valve was incised along the valve ring, and the incised edge of the leaflet was then attached to the inserted outflow patch.
Results
Fig 1 . Grade of pulmonary regurgitation. The right ventricle was vertically separated into four equal parts from the pulmonary annulus to the apex in a lateral projection of pulmona y arteriography, and pulmonary regurgitation was classified into grades (Gl, G2, G3, and G4), from least to greatest regurgitation.
fraction (RVEF), and the left ventricular ejection fraction (LVEF). Thus, RVEDV = 69.2(BSA)'.34, LVEDV = 70.6(BSA)'.31, RVEF = 0.51-0.70, and LVEF = 0.550.75. Sixty-three patients were separated into groups according to method and degree of relief of RVOT obstruction. Group I included 24 in whom a transannular patch with a single cusp was placed. Group I was further subdivided into two subgroups according to CSAI; i.e., group I-A had 13 patients with a CSAI from 1.75 to 2.5 cm2/m2 and group I-B had 11 patients with a CSAI greater than 2.5 cm2/m2.Group I1 included 27 undergoing pulmonary valvotomy, with or without a localized patch on the main PA, on the RVOT, or on both. Group 111 included 12 patients, of whom 9 underwent no valvotomy and 3 with absent pulmonary valve had pulmonary valve replacement (PVR). Of these 63 patients, 57 underwent surgery with hypothermia; the perfusate temperature was between 20 and 25°C. For 6 patients, deep hypothermia combined with circulatory arrest and limited cardiopulmonary bypass was used. Intermittent aortic cross-clamping (10 to 15 minutes) was used for the initial 28 patients. For the next 31 patients, a single period of cardiac arrest induced with Young's solution and maintained with cold-blood cardioplegia was used. The previously performed arteriopulmonary shunts in 2 patients and patent ductus arteriosus in 3 patients were ligated at the initiation of the cardiopulmonary bypass. In all patients, ventricular septa1 defects were closed with a patch by means of horizontal interrupted mattress sutures. Infundibular muscular resection was carried out to various degrees in all patients, and commissurotomy was performed at two
Late death resulting from bacterial encephalomeningitis occurred in 1 patient. Three patients underwent reoperation. Two patients, 1 of whom had initially had a transannular patch, underwent PVR for PR. A transannular patching for restenosis was performed in 1 patient. A trivial leakage at the ventricular level was detected on left ventriculography in 3 patients, but no subsequent operative procedures were required. Of 49 patients undergoing pulmonary arteriography in the early and late postoperative periods, 6 were free of PR, 28 had a PR of grades 1 or 2, and 15 had a PR of grades 3 or 4. In 3 patients undergoing PVR, PR was absent on auscultation (Table 1). A significant PR of grade 3 or 4 was present in 33% of the patients in group I-A, 87% of group I-B, 17% of group 11, and 0% of group 111. Thus, significant PR was frequent in patients who had a transannular patch and a CSAI greater than 2.5 cm2/m2.In the group I1 patients who had a valvotomy, a PR of grades 3 or 4 was present in 4 patients undergoing enforced enlargement of the pulmonary annulus by Hegar dilator. The grade of PR changed in only 2 patients. In l patient, PR that had been of grade 3 in the early postoperative period was improved to grade 2, and it elicited recurrent PS in the late postoperative period. In the other, PR deteriorated from grade 1 in the early postoperative period to grade 2 in the late postoperative period. Of 30 patients in whom the late postoperative systolic pressure gradient between RV and PA (RV-PA) was obtained, 3 had severe PS, 5 had moderate PS, and 22 had mild PS. Incidence of mild PS was 71% in group I-A, 60% in group I-B, 86% in group 11, and 67% in group 111. Figure 2 shows the relationship between the ratio of Table 1 . Grade of Pulmonary Regurgitation No. of Patients with PR of Grade: Group
0
1
2
3
4
I-A
0 0 0
1 0 10
4 4 3
0
9"
0
7 1 9 0
0
0
1-8
I1 111
3 1
'Includes 3 patients undergoing PVR;49 underwent pulmonary arteriography.
415 Oku, Shirotani, Sunakawa, et al: Correction of Tetralogy of Fallot
0.301
0.20'
4&&
I I
A
10
1
20
II I
1
1
30
40
50
60
70
RV-PA Systollc Pressure Gradient (mmHg)
Fig 2 . Znfluence of pulmonary stenosis and regurgitation on right ventricular pressure in the late postoperative period. Vertical axis indicates the right ventricular-to-aortic pressure ratio (RV/Ao). Horizontal axis indicates the right ventricular-to-pulmonary artery (RVPA) systolic pressure gradient. Numbers inside symbols refer to grade of pulmonary regurgitation.
the right ventricular-to-aortic systolic pressure (RVIAo) and the degree of PS and PR in the late postoperative period. In 30 patients, none had distal pulmonary hypertension and only 1 had a branch stenosis of the PA. Twenty-two patients had mild PS. In 21, the RV/Ao ratio was 0.50 or less, regardless of the grade of PR; the one exception was a patient with a PR of grade 4. Five patients had moderate PS. The pressure ratio was greater than 0.60 in 2 of them whose PR was of grade 3 or more, whereas the pressure ratio was less than 0.50 in the 3 patients with a PR of grade 1 or less. Thus, a PR of grade 3 or more, particularly when combined with a moderate PS, was considered a factor contributing to RV hypertension. In all 3 patients with severe PS, the PR was of grade 2. However, RV hypertension with an RV/Ao ratio of greater than 0.50 was present in 29% (Y7) of group IA, 60% (3/5) of group I-B, 7% (1/15) of group 11, and 0% (013) of group 111. There was no significant difference between the incidence in group I-A and that in group IB. Accordingly, a wider enlargement of the pulmonary annulus was not always attributed to a decrease in RV pressure in the late postoperative period when a transannular patch was used. Of 30 patients in whom the PA/Ao (pulmonary arteryto-aortic systolic) pressure ratio was measured, 4 had a pressure ratio greater than 0.40, and 26 had one less than 0.40. Of the 4 patients with a PAIAo greater than 0.40, 3 patients had a PR of grades 3 or 4, and 1 patient had a PR of grade 2 and main PA hypertension resulting from branch stenosis. Therefore, a significant PR was prone to pulmonary hypertension.
The late postoperative right ventricular end-diastolic pressure (RVEDP) was 8 mm Hg or less in all 18 patients with mild PS and in 3 patients with severe PS, regardless of the grade of PR. Five patients had a moderate PS; RVEDP was 11 mm Hg or greater in 2 of these whose PR was severe, and it was 8 mm Hg or less in all 3 patients who had a PR of grade 2 or less. However, the late postoperative LVEDP was within normal limits in all patients and averaged 7.5 mm Hg (range, 6 to 10 mm Hg). Thus, the hemodynamics of the right heart were excellent in patients with a mild PS and with a PR of grade 2 or less, and were poorest in those with a moderate PS and with a PR of grade 3 or more. The late postoperative LV hemodynamics were normal, regardless of the grade of PS or PR. Figure 3 shows the relationship between the grade of PR and the RVEDV in the early and late postoperative periods. The early postoperative RVEDV was 102 t 13% in patients with a PR of grade 0, 112 2 15% in a PR of grade 1,115 2 18% in a PR of grade 2,106 2 6% in a PR of grade 3, and 134 2 11%in a PR of grade 4. There was no significant difference among these values, though the average value in a PR of grade 4 was slightly greater than the others. In the late postoperative period, RVEDV was 139 2 13% in a PR of grade 0, 116 t 22% in a PR of grade 1,122 2 23%in a PR of grade 2,170 2 23%in a PR of grade 3, and 203 33% in a PR of grade 4. There was a significant difference between the values in three groups with a PR of grade 2 or less and those in two groups with a PR of grade 3 or more (P < 0.001). Therefore, in the late postoperative period, a PR of grade 2 or less did not enlarge RVEDV and a PR of grade 3 or more did enlarge RVEDV. Particularly, in 2 of 4 patients with a PR of grade 4, mild tricuspid regurgitation (TR) absent in the early postoperative period was detected in the late postoperative period.
*
PR
Fig 3 . Relationship between early and late postoperative right ventricular end-diastolic volume (RVEDV) and grade of pulmona ry regurgitation. Open symbols indicate the early postoperative RVEDVs. Closed symbols show late postoperative values.
416 The Annals of Thoracic Surgery Vol 41 No 4 April 1986
Table 2 . Postoperative Cardiothoracic Ratioa Postop CTR for Patients with PR of Grade: Years Postop 1 2-3 24
0
1
2
3
4
0.56 f 0.04 (N = 5) 0.53 f 0.02 (N = 3) 0.52 f 0.02 (N = 4)
0.58 f 0.04 (N = 7) 0.58 f 0.03 (N = 6) 0.53 2 0.05 (N = 7)
0.59 f 0.03 (N = 13) 0.58 ? 0.04 (N = 12) 0.54 ? 0.05
0.60 ? 0.04 (N = 10) 0.59 f 0.03 (N = 9) 0.57 ? 0.01
0.61 f 0.05 (N = 4) 0.60 ? 0.03 (N = 3) 0.60 ? 0.00
(N = 6)
(N = 2)
(N = 10)
"Numbers indicate means 2 standard deviation; N = number of patients.
PR
=
pulmonary regurgitation; CTR
=
cardiothoracic ratio.
Average value of the late postoperative RVEF was 0.48 0.03 in a PR of grade 0, 0.50 ? 0.07 in a PR of grade 1, 0.48 & 0.07 in a PR of grade 2, 0.47 t 0.04 in a PR of grade 3, and 0.47 f 0.09 in a PR of grade 4. Although RVEDV values were all less than normal, regardless of the grade of PR, RVEF was normal in 39% of the patients with a PR of grade 2 or less and only in 18% in those with a PR of grade 3 or more. Late postoperative LVEDV was 126 -+ 12% in a PR of grade 0,107 f 10% in a PR of grade 1,108 f 19%in a PR of grade 2,128 f 22% in a PR of grade 3, and 153 t 32% in a PR of grade 4. LVEF was 0.58 f 0.08, 0.56 f 0.03, 0.58 ? 0.04, 0.56 t 0.04, and 0.53 t 0.02 in a PR of grade 0 to grade 4. Thus, the average values of LVEDV and LVEF were normal or near normal in patients with a PR of grade 3 or less. In patients with a PR of grade 4, the LVEDV was mildly increased and the LVEF was slightly depressed. The postoperative cardiothoracic ratio (CTR) is shown in Table 2. The mean CTR was greater than 0.55 in all patients, regardless of the grade of PR at 1 year after repair. Two to 3 years postoperatively, the average value of CTR was normal only in patients with a PR of grade 0 and exceeded normal in those with a PR of grade 1 or more. Four to 13 years after surgery, the ratio was less than 0.55 in patients with a PR of grade 2 or less and exceeded normal in those with a PR of grade 3 or more. CTR did not relate to the degree of PS. 2
Comment Factors affecting late results after complete repair of tetralogy of Fallot include PS, PR, complete right bundle branch block, right ventriculotomy, age at operation, etc. [6-111. Of these factors, PS and PR are the most important, and the diminution of PS and PR remains the major problem. We assessed postoperative long-term results with particular attention to the relationship between PS and PR and the late hemodynamics and cardiac function after repair. As to PS which is expressed as the RV-PA pressure gradient, we reported that the early postoperative RVPA pressure gradient is mainly regulated by a CSAI, and that the wider the annulus, the lower the RV-PA pressure gradient [l, 2, 51. In the present study, the late
postoperative PS did not relate to CSAI. Particularly in patients with a transannular patch, the RV-PA pressure gradient and RV/Ao pressure ratio were both greater in group I-B with a CSAI greater than 2.5 cm2/m2than in group I-A with a CSAI of less than 2.5 cm2/m2,in contrast to the early postoperative results. This is in part related to the fact that the PR was more severe in group I-B than in group I-A, and in part to the fact that postoperative growth of the pulmonary annulus was poorer because the ratio of the widths of the autopulmonary annulus to the inserted patch was greater in group 1-8. We wish to emphasize that wider enlargement of the pulmonary annulus does not always result in a milder PS in the late postoperative period, and that a procedure which leads to excellent development of the pulmonary annulus after repair should be chosen even when a transannular patch is used. In this series, in mild and moderate PS with an RV-PA pressure gradient of less than 40 mm Hg, RVEDP, RV/ Ao, and PA/Ao pressure ratio, CTR, LVEDV, LVEF, and RVEDV were all within normal limits when a significant PR of grade 3 or more was not combined. Even in patients with a severe PS and an RV-PA pressure gradient of greater than 40 mm Hg, RVEDV, RVEDP, CTR, and LV functions were normal, though RV hypertension was present. Thus, residual RVOT obstruction can be tolerated well, if isolated [12]. However, in repair of TF, PR is elicited with high frequency [13], although the degree varies. In our study, PR was detected in all who underwent valvotomy or transannular patching. A severe PR of grade 4 was detected in patients undergoing enforced enlargement of the pulmonary annulus by Hegar dilator after valvotomy, and in those with a transannular patch and a CSAI greater than 2.5 cm2/m2. With regard to PR, Ellison and colleagues [14] found in experimental animals that the isolated PR is well tolerated over a number of years. Calder and colleagues [lo] found that PR was well tolerated clinically and hemodynamically, unless there was distal pulmonary artery or branch stenosis, whereas Shaher and co-workers [15] reported that 4 of 9 patients with PVR for PR had an isolated PR. Chiariello and associates [16] stated that PR is preferable to PS, and Hawe and co-authors [17] stated
417 Oku, Shirotani, Sunakawa, et al: Correction of Tetralogy of Fallot
that prognosis is better if PR is combined with a mild PS. In our evaluation, a PR of grade 2 or less did not influence the late hemodynamics, and a significant PR of grade 3 or more elevated the RV-PA pressure gradient [18]. Furthermore, when a severe PR was combined with a moderate PS, RVEDP was also above normal. Regarding the influence of PR on the RV function, Bove and colleagues [18] showed that the RVEF was markedly decreased in patients with PR, as compared with that in patients without PR. Generally in the present study, the average values of RVEF were decreased, regardless of the degree of PR and PS, though RVEF was normal in only one-third of the patients. The incidence of depressed RVEF is higher in patients with a significant PR than in those with a PR of grade 2 or less. However, many factors determine RV volume, including PR, RV dysfunction, size of the patch, and degree of muscular resection. Thus, the RV volume is not influenced only by PR. But the RVEDV was normal or near normal in patients with a PR of grade 2 or less and increased in those with a PR of grade 3 or more. In particular, 4 patients with a PR of grade 4 had a remarkably increased RVEDV (average value, 203%), and 2 patients had a slight TR. From these findings, we cannot help considering that a severe PR impaired RV function. Between PR and RV dilatation is a vicious circle in which the PR increases RV dilatation and the RV dilatation deteriorates PR [15]. There is a similar vicious circle for TR and RV dilatation [15]. In our 2 patients, TR was not evident in the early postoperative cardiac catheterization; therefore, it was considered to be caused by RV dilatation. The functional status of the LV in postrepair patients has been widely discussed but remains controversial. Rocchini and co-workers [191 reported normal cardiac output, LVEDP, LVEDV, and LVEF after successful repair, whereas Jarmakani and colleagues [20] noted, in cineangiographic studies, a depressed LVEF, in both preoperative and postoperative patients. Bove and coworkers [18], using radionuclide ventriculography, stated that the LVEF was considerably more normal in patients without PR than in those with PR. In our series, the late postoperative LVEDV and LVEF were normal as long as the PR was of grade 3 or less. The LVEDV was increased and the LVEF was decreased when the PR was of grade 4. Wessel and associates [12] stated that exercise tolerance strongly decreases when PR coexists with PS. Their results corresponded with our finding that postoperative late hemodynamics and cardiac function were poorest in patients with a PR of grade 3 or more and a moderate PS. CTR was enlarged in patients with PR [18]. In our study, the CTR was above normal 1 year after surgery, regardless of the grade of PR. CTR was restored to normal in patients with a PR of grade 2 or less 4 years after surgical repair, but in patients with a PR of grade 3 or more it was still higher than normal even 4 years after repair. As mentioned previously, opinions vary with regard to the influence of PR on postoperative hemodynamics
and cardiac function. This is considered to be due in part to differences in estimation of the PR, and in part to the lack of an accurate and convenient method to measure regurgitant volume. We classified PR into four grades, according to reflux of the contrast medium into RV in the lateral projection of the pulmonary arteriography. Although our grading of PR does not always reflect a regurgitant volume accurately and is only an approximation because the expanding area and light and shade of the contrast medium are not taken into consideration, the grades do coincide with clinical findings and with hemodynamic and volumetric data. In our classification, a PR of grade 2 or less was irrelevant and harmless, and a PR of grade 3 or more was considered to be hemodynamically and functionally significant, and it impaired the late postoperative hemodynamics and cardiac functions. In particular, a PR of grade 4 depressed LV function. Thus, to maintain excellent postoperative hemodynamics and cardiac function, it is imperative to obtain a PR of grade 2 or less. To prevent severe PR, Kawashima and colleagues [21] used several fine procedures in reconstruction of RVOT and obtained excellent results. In our conventional procedure using a transannular patch, a CSAI of less than 2.5 cm2/m2and a more precise coaptation between original pulmonary cusp and the cusp mounted on the patch could avoid a PR of grade 3 or more. An enforced enlargement using a dilator should not be done after valvotomy.
References 1. Oku H: Operative results and postoperative hemodynamic results in total correction of tetralogy of Fallot. Nippon Geka Hokan 45937, 1976 2. Oku H, Shirotani H, Yokoyama T, et al: Postoperative size of the right ventricular outflow tract and optimal age in complete repair of tetralogy of Fallot. Ann Thorac Surg 25:322, 1978 3. Naito Y, Fujita T, Manabe H, Kawashima Y: The criteria for reconstruction of right ventricular outflow tract in total correction of tetralogy of Fallot. J Thorac Cardiovasc Surg 80574, 1980 4. Blackstone EH, Kirklin JW, Bertranou EG, et al: Preoperative prediction from cineangiograms of postrepair right ventricular pressure in tetralogy of Fallot. J Thorac Cardiovasc Surg 7 8 9 2 , 1979 5. Oku H, Shirotani H, Yokoyama T, et al: Right ventricular outflow tract prosthesis in total correction of tetralogy of Fallot. Circulation 62:604, 1980 6. Borow KM, Green LH, Castaneda AR, Keane JF.: Left ventricular function after repair of tetralogy of Fallot and its relationship to age at surgery. Circulation 61:1150, 1980 7. Katz NM, Blackstone EH, Kirklin JW, et al: Late survival and symptoms after repair of tetralogy of Fallot. Circulation 65:403, 1982 8. Yasui H, Takeda Y, Yamauchi S, et al: The deleterious effects of surgically induced complete right bundle branch block on long-term follow-up results of closure of ventricular septa1 defect. J Thorac Cardiovasc Surg 74210, 1977 9. Sanger PW, Robicsek F, Taylor FH, Davis SC: A method of preventing myocardial damage by using a modified ventriculotomy incision. Ann Surg 155:874, 1962
418 The Annals of Thoracic Surgery Vol 41 No 4 April 1986
10. Calder AL, Barratt-Boyes BG, Brandt PWT, Neutze JM: Postoperative evaluation of patients with tetralogy of Fallot repaired in infancy. J Thorac Cardiovasc Surg 77704, 1979 11. Bristow JD, Kloster FE, Lees MH, et al: Serial cardiac catheterizations and exercise hemodynamics after correction of tetralogy of Fallot. Circulation 41:1057, 1970 12. Wessel HU, Cunningham WJ, Paul MH, et al: Exercise performance in tetralogy of Fallot after intracardiac repair. J Thorac Cardiovasc Surg 80:582, 1980 13. Arciniegas E, Farooki ZQ, Hakimi M, et al: Early and late results of total correction of tetralogy of Fallot. J Thorac Cardiovasc Surg 80:770, 1980 14. Ellison RG, Brown WJ Jr, Yeh TJ, Hamilton WF: Surgical significance of acute and chronic pulmonary valvular insufficiency. J Thorac Cardiovasc Surg 60549, 1970 15. Shaher RM, Foster E, Farina M, et al: Right heart reconstruction following repair of tetralogy of Fallot. Ann Thorac Surg 35:421, 1983 16. Chiariello L, Meyer J, Wukasch DC, et al: Intracardiac re-
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