Eur .I Cardio-[hnrac
Surg (1990) 4: 35Y-364
Surgery of atrioventricular septal defects Review of the first 100 cases C. Lozano ‘, M. Rovirosa ‘, J. Reig ‘, and J. A. Salva A ’ Department ’ Department ’ Dcpartmcnt
of Cardiac Surgery. Vail d’Hcbrbn Hospital for Children. of Morphological Sciences. Medical School. and of Surgery. School of Medicine. Autonomous University of Barcelona.
Abstract. From 1971 to 1985, the first 100 children suffering from some form of atrio-ventricular septal defect underwent surgical correction. In all cases, corrective surgery was carried out primarily except in 3 children who presented with a total defect and first underwent palliative surgery. In 48 children, a complete form was present, in 5 an intermediate form, and in 47 a partial form. There were 43 males and 57 females. Thirty-eight percent of patients suffered from Down’s syndrome. The mean age at operation was 42 (range 2-143) months. A prosthesis was implanted in the left atrio-ventricular valve at primary correction in 9 patients. Up to 1980, the overall mortality was 20% and from 1981 to 1985 it was 3.3%. Thcrc was late mortality in 3 children (2 with a complete form and 1 partial). In 32 cases, postoperative cardiac catheterization was performed. Nine patients were reoperated upon (9%). 2 due to a residual shunt, 4 due to serious mitral incompetence (in all cases a prosthesis was used). and 3 due to valvular thrombosis. In this series. only 2 patients remained in complete atrio-ventricular block (1 affected by the complete form and the other partial). Long term survival is related to the severity of left valvular insufficiency. In this series with a mean follow-up of 3.83 + 2.78 years, we had an a cumulative survival of 86.7% f 3.43%. At the last control, most of the survivors had a good quality of life: 91% were in class I and 9% in class II according to the NYHA scale. [Eur J Cardio-thorac Surg ( 1990) 4: 359-- 3641 Key words: Atrioventricular vascular disease
septal defects
Pulmonary
The various atrio-ventricular (AV) septal defects are congenital cardiac anomalies which are difficult to correct due to the complexity of the anatomical lesions. In the complete form, the prognosis is not good due to pulmonary vascular obstructive disease unless surgery is carried out early in life. In this paper, we present the retrospective results of the first 100 consecutive cases of AV RccriLed ttir publication: September 1X. 1989 /\cceptcd for publication: February 2. 1990
Barcelona, Spain
septal defects operated upon at the Vall d’Hebr6n Children’s Hospital in Barcelona. Early and late mortality, evolution of pulmonary hypertension. and survival curves are analysed.
Material and methods From October 1972 to November 1985, the first IO0 patients with AV septal defects were operated upon. In all. corrective surgery was used primarily. except in 3 cases with a complete form who previously underwent palliative surgery. Thcrc were slightly more fcmales than males: 57 vs. 43. The Wakai and Edwards classification [23. 341 ‘was used. so a complete. an intermediate and a partial form were recognisrd. Thus, 48 (48%) were classified as complete 5 (5%) as intermediate and 47 (47%) as partial. Thirty-eight percent of the cases were associated with Down’s syndrome (84% of these were the complete form; II = 32). Except in the complete form, other syndromes were rarely associated. The mean age at operation was 42 (range 2-143) months. The weight varied from 3 kg to 31 kg (mean: 12.X+ 5.5 kg). Some degree ofcongestive heart failure (CHF). varying from an isolated symptom to repeated respiratory infections or a deficient height-weight curve. was seen in the complctc and intermediate forms (74% of patients). Of the 47 patients with the partial form. 2 (4.3%) came to hospital with CHF responding poorly to medical treatment and thus required urgent surgery. Twenty-two patients with the partial form had no symptoms as did 1 cast of the complctc form. Nine patients had CHF refractory to medical treatment, 7 being complete cases and 2 partial. At the time of surgery. 20 of the 100 patients were under 1 year old. Thirteen (65%) had the complete form. I (5”/;,) had the intermediate form and 6 (30%) had the partial form. In this group, CHF was usual and was always related to a very low height-weight curve. For the results. the operations have been divided into two periods: up to 1980 and 1981~ 1985.
All palients underwent cardiac catheterization and 411patients had a complete form with a pulmonary artery systolic pressure (pPA) ranging from 26 to 113 mmHg (mean: 64.17* 19.38). In 36 patients (77%). it was above 50 mmHg and no case was hclow 20. The mean pressure in the pulmonary artery (mPA) was 44.25 t_:15.95mmHg (20-79 mmHg). The ratio between pulmonary and systemic resistancc (RJR,) had a mean of 0.42kO.27 (0.04- 1..20). The pulmonary arteriolar resistance (PAR) had a mean of 4.08 + 2.7 IU jm’ (0.2 9.9).
360 In the intermediate form, the pPA ranged from 24 to 87 mmHg (mean: 55.40 + 26.67 mmHg), the mPA between 15 and 63 mmHg (mean: 39.20+21.00 mmHg); the RJR, ratio varied from 0.04 to 1.3 (mean: 0.50f0.57); the PAR varied from 0.8 to 9.9 IU/mZ (mean: 4.4k4.4). In the partial form, the pPA had a mean of 34.25 mmHg (1572 mmHg). It was more than 50 mmHg in 7 cases. The mPA showed values of IO-50 mmHg (mean: 21.97& 10.54 mmHg). The RJR, was 0.03-0.90 (mean: 0.11 kO.15) and the PAR from 0.4 to 8.2 III/m’ (mean: 1.6 f 1.7). The surgical indications were based on CHF, pulmonary hypertension and the impossibility of keeping the children under treatment. In the partial form - mostly asymptomatic - the indication was elective.
form. The mortality in those with the complete form was due in 3 cases to low cardiac output, in 1 to a ventricular fibrillation, and in another to persistent haematuria which resulted in renal failure. One patient died in the operation room; the intraoperative pulmonary biopsy indicated the presence of angiomatous and plexiform lesions. Of the patients with the partial form, two children died because of low cardiac output, one of sepsis by Candida albicans, and the remainder because of ventricular fibrillation. There were three cases of late mortality. Two children had the complete form of AV septal defect and 1 the partial form. The latter and one of the complete type were reoperated on due to serious mitral incompetence. The other patient with the complete form died suddenly at home; no postmortem examination was performed.
Surgical technique By median sternotomy and pericardiotomy, both venae cavae were cannulated separately with curved cannulas and arterial perfusion was carried out through a cannula in the ascending aorta. The vent was placed in the apex of the left ventricle. Moderate esophageal hypothermia of 28°C was induced and intermittent aortic crossclamping for less than 10 min was performed. We used the technique described by Rastelli et al. [17], closing both defects with a single patch. In the three cases with previous palliative surgery, the pulmonary artery trunk was corrected prior to the repair of the AV septal defect. Neither the pulmonary valve nor the bifurcation of the pulmonary arteries showed damage in any case. In the partial form, once the mitral cleft was fixed in place with loose stitches, the interatrial defect was corrected through a patch at the base of the septal leaflet of the mitral valve. In all cases, the coronary sinus remained in its anatomical position. The duration of aortic cross-clamping ranged from 0 to 95 min (mean: 18.34f 19.78 min).
Prosthesis
In the primary correction, the implantation of a prosthesis in the left AV valve was necessary in 9% of the patients (n = 9; Table 2); 6 cases had the complete form of defect, 2 the intermediate form, and 1 the partial form. Postoperative cardiac catheterization In this series, 32 postoperative cardiac catheterizations were carried out (in 17 males and 15 females) with an interval after surgery that varied from 15 days to 6 years and 3 months (mean: 2 years 8 months). Fifteen patients had the complete form of AV septal defect, 2 the intermediate and 15 the partial. The indication for postoperative catheterization was the need to examine the competence of the AV valves and the evolution of the pulmonary vascular resistances. Two patients had residual shunts so that they should be reoperated upon without problems. Serious left valvular insufficiency was only found in 1 case, corresponding to a partial form; in 4 cases it was moderate; in 10 cases slight, and in the remaining 17 cases no incompetence of this valve was found. There was right AV valve insufficiency in 5 cases, all of which were considered to be slight. There was no sign of insufficiency in the remaining 24 cases. The values of the haemodynamic data are shown in Table 3. The 15 cases of the complete form were divided into 2 groups according to age of the patient, to see the evolution of the pulmonary vascular disease. In the first group, 56% of cases (n = 5) were associated with Down’s syndrome, and in the second group 83% of cases (n = 5). The anaesthesia characteristics were similar in both groups.
Statistical metho& To evaluate the pulmonary vascular disease, the mPA, the P,/P, and the R&R, were used. The results are expressed as the mean+ 1 standard deviation. W Statistic was used to test that the data were normally distributed. This showed that some variables were not normally distributed and nonparametric tests were used: l Preoperative and postoperative data were processed by means of the Wilcoxon sign rank test (paired comparison). l The comparison of data between the two age groups was processed by means of the Wilcoxon 2-sample test. A P value below 0.05 was considered to be significant. Statistical analysis was carried out using the BMDP Statistical Package.
Results Mortality
The hospital mortality of this series is shown in Table 1. There was no mortality in patients with the intermediate
Table 1. Hospital deaths after repair of atrioventricular Year of operation
1972-1980 1981-1985
septal defect according Intermediate
Complete type
to the year of operation Total
Partial type
type
n
Deaths
%
n
Deaths
%
n
Deaths
%
n
Deaths
%
10 38
4 2
40.0 5.3
2 3
_ _
_ _
28 19
4 _
14.3 _
40 60
8 2
20.0 3.3
361 Table 2. Atrioventricular
septal dcfccts: prosthesis
in primary correction
Case
Type
Age (months)
Weight (kg)
NYHA follow-up class
Anatomical
characteristics
I
Complete
77
17
II
Single papillary muscle
Bjork 21
?
Partial
48
15.6
I
Accessory orifice. short chords obstructing principal oriticc
Hjork 13 Bjork 19
Prosthesis
3
Intcrmcdiatc
lh
7.8
I
Parachute
1
Complete
34
6
I
Fenestrated
5
(‘omplete
16
7
II
Double mitral
6
(‘nmpletc
18
8
I
Hypoplasia of the anterior valve, single papillary muscle
Bjnrk ?I
7
Intermediate
34
10
II
Parachute
St Jude 19
x
Complete
16
16
1
Dysplastic mitral valve
Bjork 17
0
Complete
30
10
II
Single papillary muscle. hypoplasia of the anterior valve
Bjnrk 21
mitral valve valve
St Jude 19
orifice
St
mitral valve
Jude 19
Table 3. Changes o\ er time in the hacmodynamic
data (mean + SD) with postopcrativ,c cardiac catheterization after corrcction of‘ atrtovcntricular septal dcfcct (completc type) 01‘ 1.‘1patients
Huemndynamic dat:t
Prcopcralivc
Postoperative
pPA
(mmH$)
P 40.0001
(mmHf)
63.37 + 10.05 11.67& IX.27
38.67_+ 17.74
mP4
x37*
Pi
R,,‘R.
O.J1 +(I.‘7
0.15+_
60 1
12.70 0.1
I
0.005
G I
LO-
:
PiO.005
% E
mPA = mean prcssurc of the pulmonary artery; pPA = systolic pressure of the pulmonary artery: R,. R.=ratio bctwecn pulmonary and systemic resistance
In Table 4 we reproduce all pre- and postoperative data with statistical analysis for the total and for separate groups. l mPA (Fig. 1): There was a significant drop in the mPA in the total postsurgical study. However, group analysis shows that a significant fall occurred only in group I’ (PC 0.002). There were no significant differences between the groups in both the pre- and the postoperative studies. l P,/P, (Fig. 2): The analysis of the groups shows a significant drop in both. However, there were no significant differences between group 1 and 2 either in the pre- or the postoperative period. l RJR, (Fig. 3): In group 1 there was a wide range in the preoperative period (from 0.07 to 0.91). Comparing the pre- and postoperative values. there was a significant drop in group 1 (P< 0.0 I)but not in group 2.
20
1
OL-, Preop
Fig. 1. Mean pulmonary artcry prcssurc (niPA) before and after repair. G-l. Patients operated before 2 years of age: G-L Patients operated after 7 years of age
1.20,
OG-1
I
1.08
0 96
i G
084
r- -P NS L,,
I
-:
072
/
2 060 \ E 048 0 36
Of the ‘? patients reoperated (9%) 5 had the complete form of defect, 1 the intermediate and 3 the partial form. In 2 patients the reason for reoperation was a residual shunt: in 4 it was a serious residual valvular insufficiency, 3 of these patients having the complete form and 2 the partial. Three patients with prosthesis required reoperation for valvular thrombosis. There was no mortality in
Postop
I ;-p
Surg (1990) 4: 35Y-364
Surgery of atrioventricular septal defects Review of the first 100 cases C. Lozano ‘, M. Rovirosa ‘, J. Reig ‘, and J. A. Salva A ’ Department ’ Department ’ Dcpartmcnt
of Cardiac Surgery. Vail d’Hcbrbn Hospital for Children. of Morphological Sciences. Medical School. and of Surgery. School of Medicine. Autonomous University of Barcelona.
Abstract. From 1971 to 1985, the first 100 children suffering from some form of atrio-ventricular septal defect underwent surgical correction. In all cases, corrective surgery was carried out primarily except in 3 children who presented with a total defect and first underwent palliative surgery. In 48 children, a complete form was present, in 5 an intermediate form, and in 47 a partial form. There were 43 males and 57 females. Thirty-eight percent of patients suffered from Down’s syndrome. The mean age at operation was 42 (range 2-143) months. A prosthesis was implanted in the left atrio-ventricular valve at primary correction in 9 patients. Up to 1980, the overall mortality was 20% and from 1981 to 1985 it was 3.3%. Thcrc was late mortality in 3 children (2 with a complete form and 1 partial). In 32 cases, postoperative cardiac catheterization was performed. Nine patients were reoperated upon (9%). 2 due to a residual shunt, 4 due to serious mitral incompetence (in all cases a prosthesis was used). and 3 due to valvular thrombosis. In this series. only 2 patients remained in complete atrio-ventricular block (1 affected by the complete form and the other partial). Long term survival is related to the severity of left valvular insufficiency. In this series with a mean follow-up of 3.83 + 2.78 years, we had an a cumulative survival of 86.7% f 3.43%. At the last control, most of the survivors had a good quality of life: 91% were in class I and 9% in class II according to the NYHA scale. [Eur J Cardio-thorac Surg ( 1990) 4: 359-- 3641 Key words: Atrioventricular vascular disease
septal defects
Pulmonary
The various atrio-ventricular (AV) septal defects are congenital cardiac anomalies which are difficult to correct due to the complexity of the anatomical lesions. In the complete form, the prognosis is not good due to pulmonary vascular obstructive disease unless surgery is carried out early in life. In this paper, we present the retrospective results of the first 100 consecutive cases of AV RccriLed ttir publication: September 1X. 1989 /\cceptcd for publication: February 2. 1990
Barcelona, Spain
septal defects operated upon at the Vall d’Hebr6n Children’s Hospital in Barcelona. Early and late mortality, evolution of pulmonary hypertension. and survival curves are analysed.
Material and methods From October 1972 to November 1985, the first IO0 patients with AV septal defects were operated upon. In all. corrective surgery was used primarily. except in 3 cases with a complete form who previously underwent palliative surgery. Thcrc were slightly more fcmales than males: 57 vs. 43. The Wakai and Edwards classification [23. 341 ‘was used. so a complete. an intermediate and a partial form were recognisrd. Thus, 48 (48%) were classified as complete 5 (5%) as intermediate and 47 (47%) as partial. Thirty-eight percent of the cases were associated with Down’s syndrome (84% of these were the complete form; II = 32). Except in the complete form, other syndromes were rarely associated. The mean age at operation was 42 (range 2-143) months. The weight varied from 3 kg to 31 kg (mean: 12.X+ 5.5 kg). Some degree ofcongestive heart failure (CHF). varying from an isolated symptom to repeated respiratory infections or a deficient height-weight curve. was seen in the complctc and intermediate forms (74% of patients). Of the 47 patients with the partial form. 2 (4.3%) came to hospital with CHF responding poorly to medical treatment and thus required urgent surgery. Twenty-two patients with the partial form had no symptoms as did 1 cast of the complctc form. Nine patients had CHF refractory to medical treatment, 7 being complete cases and 2 partial. At the time of surgery. 20 of the 100 patients were under 1 year old. Thirteen (65%) had the complete form. I (5”/;,) had the intermediate form and 6 (30%) had the partial form. In this group, CHF was usual and was always related to a very low height-weight curve. For the results. the operations have been divided into two periods: up to 1980 and 1981~ 1985.
All palients underwent cardiac catheterization and 411patients had a complete form with a pulmonary artery systolic pressure (pPA) ranging from 26 to 113 mmHg (mean: 64.17* 19.38). In 36 patients (77%). it was above 50 mmHg and no case was hclow 20. The mean pressure in the pulmonary artery (mPA) was 44.25 t_:15.95mmHg (20-79 mmHg). The ratio between pulmonary and systemic resistancc (RJR,) had a mean of 0.42kO.27 (0.04- 1..20). The pulmonary arteriolar resistance (PAR) had a mean of 4.08 + 2.7 IU jm’ (0.2 9.9).
360 In the intermediate form, the pPA ranged from 24 to 87 mmHg (mean: 55.40 + 26.67 mmHg), the mPA between 15 and 63 mmHg (mean: 39.20+21.00 mmHg); the RJR, ratio varied from 0.04 to 1.3 (mean: 0.50f0.57); the PAR varied from 0.8 to 9.9 IU/mZ (mean: 4.4k4.4). In the partial form, the pPA had a mean of 34.25 mmHg (1572 mmHg). It was more than 50 mmHg in 7 cases. The mPA showed values of IO-50 mmHg (mean: 21.97& 10.54 mmHg). The RJR, was 0.03-0.90 (mean: 0.11 kO.15) and the PAR from 0.4 to 8.2 III/m’ (mean: 1.6 f 1.7). The surgical indications were based on CHF, pulmonary hypertension and the impossibility of keeping the children under treatment. In the partial form - mostly asymptomatic - the indication was elective.
form. The mortality in those with the complete form was due in 3 cases to low cardiac output, in 1 to a ventricular fibrillation, and in another to persistent haematuria which resulted in renal failure. One patient died in the operation room; the intraoperative pulmonary biopsy indicated the presence of angiomatous and plexiform lesions. Of the patients with the partial form, two children died because of low cardiac output, one of sepsis by Candida albicans, and the remainder because of ventricular fibrillation. There were three cases of late mortality. Two children had the complete form of AV septal defect and 1 the partial form. The latter and one of the complete type were reoperated on due to serious mitral incompetence. The other patient with the complete form died suddenly at home; no postmortem examination was performed.
Surgical technique By median sternotomy and pericardiotomy, both venae cavae were cannulated separately with curved cannulas and arterial perfusion was carried out through a cannula in the ascending aorta. The vent was placed in the apex of the left ventricle. Moderate esophageal hypothermia of 28°C was induced and intermittent aortic crossclamping for less than 10 min was performed. We used the technique described by Rastelli et al. [17], closing both defects with a single patch. In the three cases with previous palliative surgery, the pulmonary artery trunk was corrected prior to the repair of the AV septal defect. Neither the pulmonary valve nor the bifurcation of the pulmonary arteries showed damage in any case. In the partial form, once the mitral cleft was fixed in place with loose stitches, the interatrial defect was corrected through a patch at the base of the septal leaflet of the mitral valve. In all cases, the coronary sinus remained in its anatomical position. The duration of aortic cross-clamping ranged from 0 to 95 min (mean: 18.34f 19.78 min).
Prosthesis
In the primary correction, the implantation of a prosthesis in the left AV valve was necessary in 9% of the patients (n = 9; Table 2); 6 cases had the complete form of defect, 2 the intermediate form, and 1 the partial form. Postoperative cardiac catheterization In this series, 32 postoperative cardiac catheterizations were carried out (in 17 males and 15 females) with an interval after surgery that varied from 15 days to 6 years and 3 months (mean: 2 years 8 months). Fifteen patients had the complete form of AV septal defect, 2 the intermediate and 15 the partial. The indication for postoperative catheterization was the need to examine the competence of the AV valves and the evolution of the pulmonary vascular resistances. Two patients had residual shunts so that they should be reoperated upon without problems. Serious left valvular insufficiency was only found in 1 case, corresponding to a partial form; in 4 cases it was moderate; in 10 cases slight, and in the remaining 17 cases no incompetence of this valve was found. There was right AV valve insufficiency in 5 cases, all of which were considered to be slight. There was no sign of insufficiency in the remaining 24 cases. The values of the haemodynamic data are shown in Table 3. The 15 cases of the complete form were divided into 2 groups according to age of the patient, to see the evolution of the pulmonary vascular disease. In the first group, 56% of cases (n = 5) were associated with Down’s syndrome, and in the second group 83% of cases (n = 5). The anaesthesia characteristics were similar in both groups.
Statistical metho& To evaluate the pulmonary vascular disease, the mPA, the P,/P, and the R&R, were used. The results are expressed as the mean+ 1 standard deviation. W Statistic was used to test that the data were normally distributed. This showed that some variables were not normally distributed and nonparametric tests were used: l Preoperative and postoperative data were processed by means of the Wilcoxon sign rank test (paired comparison). l The comparison of data between the two age groups was processed by means of the Wilcoxon 2-sample test. A P value below 0.05 was considered to be significant. Statistical analysis was carried out using the BMDP Statistical Package.
Results Mortality
The hospital mortality of this series is shown in Table 1. There was no mortality in patients with the intermediate
Table 1. Hospital deaths after repair of atrioventricular Year of operation
1972-1980 1981-1985
septal defect according Intermediate
Complete type
to the year of operation Total
Partial type
type
n
Deaths
%
n
Deaths
%
n
Deaths
%
n
Deaths
%
10 38
4 2
40.0 5.3
2 3
_ _
_ _
28 19
4 _
14.3 _
40 60
8 2
20.0 3.3
361 Table 2. Atrioventricular
septal dcfccts: prosthesis
in primary correction
Case
Type
Age (months)
Weight (kg)
NYHA follow-up class
Anatomical
characteristics
I
Complete
77
17
II
Single papillary muscle
Bjork 21
?
Partial
48
15.6
I
Accessory orifice. short chords obstructing principal oriticc
Hjork 13 Bjork 19
Prosthesis
3
Intcrmcdiatc
lh
7.8
I
Parachute
1
Complete
34
6
I
Fenestrated
5
(‘omplete
16
7
II
Double mitral
6
(‘nmpletc
18
8
I
Hypoplasia of the anterior valve, single papillary muscle
Bjnrk ?I
7
Intermediate
34
10
II
Parachute
St Jude 19
x
Complete
16
16
1
Dysplastic mitral valve
Bjork 17
0
Complete
30
10
II
Single papillary muscle. hypoplasia of the anterior valve
Bjnrk 21
mitral valve valve
St Jude 19
orifice
St
mitral valve
Jude 19
Table 3. Changes o\ er time in the hacmodynamic
data (mean + SD) with postopcrativ,c cardiac catheterization after corrcction of‘ atrtovcntricular septal dcfcct (completc type) 01‘ 1.‘1patients
Huemndynamic dat:t
Prcopcralivc
Postoperative
pPA
(mmH$)
P 40.0001
(mmHf)
63.37 + 10.05 11.67& IX.27
38.67_+ 17.74
mP4
x37*
Pi
R,,‘R.
O.J1 +(I.‘7
0.15+_
60 1
12.70 0.1
I
0.005
G I
LO-
:
PiO.005
% E
mPA = mean prcssurc of the pulmonary artery; pPA = systolic pressure of the pulmonary artery: R,. R.=ratio bctwecn pulmonary and systemic resistance
In Table 4 we reproduce all pre- and postoperative data with statistical analysis for the total and for separate groups. l mPA (Fig. 1): There was a significant drop in the mPA in the total postsurgical study. However, group analysis shows that a significant fall occurred only in group I’ (PC 0.002). There were no significant differences between the groups in both the pre- and the postoperative studies. l P,/P, (Fig. 2): The analysis of the groups shows a significant drop in both. However, there were no significant differences between group 1 and 2 either in the pre- or the postoperative period. l RJR, (Fig. 3): In group 1 there was a wide range in the preoperative period (from 0.07 to 0.91). Comparing the pre- and postoperative values. there was a significant drop in group 1 (P< 0.0 I)but not in group 2.
20
1
OL-, Preop
Fig. 1. Mean pulmonary artcry prcssurc (niPA) before and after repair. G-l. Patients operated before 2 years of age: G-L Patients operated after 7 years of age
1.20,
OG-1
I
1.08
0 96
i G
084
r- -P NS L,,
I
-:
072
/
2 060 \ E 048 0 36
Of the ‘? patients reoperated (9%) 5 had the complete form of defect, 1 the intermediate and 3 the partial form. In 2 patients the reason for reoperation was a residual shunt: in 4 it was a serious residual valvular insufficiency, 3 of these patients having the complete form and 2 the partial. Three patients with prosthesis required reoperation for valvular thrombosis. There was no mortality in
Postop
I ;-p
