ArliJiciuf 0rgm.s
20(6):724-727. Blackwell Science. Inc., Boston 0 1996 International Society for Artificial Organs
Biventricular Bypass with Oxygenation for Postcardiotomy Ventricular Failure Kohjiro Kodera, Masaya Kitamura, Mitsuhiro Hachida, Masahiro Endo, Akimasa Hashimoto, and Hitoshi Koyanagi Department of Cardiovascular Surgery, The Heart Institute of Japan, Tokyo Women’s Mtdicul College, Tokyo, Jupun
Abstract: Between January 1984 and March 1995, biventricular bypass (BVB) with oxygenation was used in 17 patients for postcardiotomy ventricular failure at the Heart Institute of Japan, Tokyo Women’s Medical College. Of the 17 patients, 12 (70.6%)were weaned from the circulatory support, and 8 (47.1%) were discharged from the hospital. The time interval from the end of cardiopulmonary bypass to the start of BVB was significantly shorter in weaned patients than in unweaned patients. The duration on support also has been shortened signifi-
cantly in the last 6 years, compared with the earlier 6 years. Causes of death were severe heart failure or ventricular arrhythmia in 6 patients and multiple organ failure in 3 patients. These results suggest that early application and timely weaning from biventricular bypass with OXYgenation might be the effective circulatory support of choice for treatment of postcardiotomy ventricular failure. Key Words: Biventricular bypass-Circulatory support-Postcardiotomy ventricular failure.
In recent years, standard open heart operations with effective myocardial protection have been performed successfully at many medical centers. However, approximately 1% of patients after cardiac operations have shown severe heart failure or cardiogenic shock (1-3’). We have developed and used a biventricular bypass (BVB) circuit (43) with oxygenation clinically for the treatment of postcardiotomy ventricular failure. The purpose of this study is the evaluation of clinical results of BVB for postcardiotomy ventricular failure at our institution.
of these patients were men, and 6 (35.3%) were women. The age of patients ranged from 22 to 64 years, and the mean age was 41.4 years. Fourteen of the patients had valvular heart disease, and 3 had coronary artery disease. Surgical procedures in this series of patients were aortic valve replacement in 6 cases, mitral valve replacement in 5, aortomitral double-valve replacement in 3, and coronary artery bypass grafting in 3 (Table 1). Description of the biventricular bypass A diagram of our BVB circuit is shown in Fig. 1 (4-6). This system consists of a centrifugal pump (BioMedicus, Inc., Eden Prairie, Minnesota, U .S.A.) or a roller pump, right and left atrial drainage cannulae, aortic cannula, and a membrane oxygenator. A right atrial cannula is placed through the right atrial appendage. A left atrial cannula is inserted through the right upper pulmonary vein or the left atrial appendage. An aortic cannula is placed in the ascending aorta or the femoral artery. Drainage flow is autoregulated according to the pressure of the right and left atria, thus offering appropriate circulatory support for bilateral ventricular failure. The BVB circuit is converted easily to univentricular bypass by clamping the right or left atrial can-
PATIENTS AND METHODS Patients From January 1984 to March 1995, 17 patients with postcardiotomy ventricular failure were supported using BVB at the Heart Institute of Japan, Tokyo Women’s Medical College. Eleven (64.7%) Received January 1996. Address correspondence to Dr. Kohjiro Kodera, Department of Cardiovascular Surgery, The Heart Institute of Japan, Tokyo Women’s Medical College, 8- I Kawada-cho, Shinjuku-ku, Tokyo 162, Japan.
724
POSTCARDIOTOMY VENTRICULAR FAILURE
725
TABLE 1. Surgical procedures and patients Procedure (total patients)
Male
Female
AVR (6) MVR ( 5 ) DVR (3) CABG (3) Total (17)
I
AVR, aortic valve replacement; MVR, mitral valve replacement; DVR, aortomitral double valve replacement; CABG, coronary artery bypass grafting.
nula, depending on the recovery of either ventricle's function. A hard reservoir is placed to reinfuse the suctioned blood in the early postoperative period. After complete hemostasis, this hard reservoir is not necessary. The indication for clinical use of this system is thought to be poor ventricular function (peak arterial pressure, less than 90 mm Hg; pulmonary capillary wedge pressure, more than 18 mm Hg; cardiac index, less than 1.8 L/min/m2) and/or a fatal ventricular arrhythmia despite use of a maximal dose of isotropic supports and intraaortic balloon pumping (IABP) (1,2,7,8). RESULTS
Overall weaning and discharge rates are shown in Fig. 2 and Table 2. Twelve of 17 patients could be weaned from the circulatory support with a weaning rate of 70.6%. Of these 12 patients, 8 were discharged from the hospital for an overall discharge rate of 47.1%. Five patients could not be weaned from circulatory support, and the cause of death was thought to be profound heart failure in all 5 cases. Four patients died after weaning from the circulatory support. Of these 4 patients, 3 died of multiple organ failure, and 1 died of recurrent congestive heart failure on the 140th postoperative day. Tables 3 and 4 show the duration on the circulatory support. In all cases, the duration of support in from RA to Aorta
I
from LA
Suction
I
I Weaned: 70.6% Total: 17 patients
FIG. 2. The overall rates of weaning and discharge are shown.
unweaned patients (51.6 rf: 9.3 h) was significantly longer than that in the weaned patients (17.9 & 6.2 h). Of the weaned patients, those who died tended to have a longer duration of support (31.0 -+ 12.8 h) than did the discharged patients (11.3 ? 6.0 h). In addition, the duration of support, weaning, and discharge rates were compared for early (19841989) and late (1990-1995) periods (Table 5). The duration of support was significantly shorter in the late period (Fig. 3). In the late period, the weaning and discharge rates showed some trend toward higher percentages than those in the early period. Table 6 shows the time interval from the end of initial CPB and the introduction of BVB. In the weaned group, it was significantly shorter (2.85 2 1.8 h) than in the unweaned group (15.8 rf: 7.5 h). The long-term actuarial survival proportion is shown in Fig. 4. One of the discharged patients died of ventricular arrhythmia in the long-term period (Table 7). The survival rate at 5 years, including early deaths, was 30.9%; however, in the group of discharged patients, the 5-year survival was 66.7%. DISCUSSION
According to the 1994 Report of the International Combined Registry (9), 42.6% (204 of 479) of patients receiving biventricular assistance were weaned from the support, and 23.0% (110 of 479) were discharged from the hospital. In the present study of 17 patients at the Heart Institute of Japan, 70.6% of the TABLE 2. Overall weaning and discharged rates
Procedure
Patients
Weaned
Discharged
Number (%)
Number (%)
FIG. 1. A diagram of the BVB circuit is shown. Note that the height of the soft reservoir changes electrically. Artif Organs. Vol. 20, N o . 6, 1996
K . KODERA ET A L .
726
TABLE 3. Support duration in all cases H
Weaned patients (n = 12) Unweaned patients (n = 5) Values are expressed as the mean
17.9 2 6.2 51.6 19.3
*
k
SE; p < 0.05.
patients could be weaned from circulatory support, and 47.1% were discharged from the hospital. Eightythree percent (14 of 17) of the patients with BVB had valvular heart disease, and the other patients (3 of 17) had ischemic heart disease. Postcardiotomy patients having valvular heart disease frequently show biventricular failure. In contrast, left ventricular support was used for 8 (72.7%) of 1 1 patients with severe cardiac failure after coronary artery bypass grafting (CABG) during the same period because the majority of the patients with ischemic heart disease had isolated left ventricular failure. Our BVB set-up was reported originally in 1974 (4), and it has been used clinically at our institution since then. In emergency acute cardiac failure, it is often difficult to know which particular ventricular function is impaired. As reported by Pennington et al. (8), management of biventricular failure in the early postoperative period is important. We usually use the BVB circuit in patients who may have biventricular failure with or without respiratory insufficiency. The BVB circuit consists of a blood pump, right and left atrial drainage cannulae, aortic cannula, and a membrane oxygenator. The distinguishing characteristic of this circuit is a Y-configured drainage unit. Drainage blood flow is regulated automatically according to left and right atrial pressures and is controlled by changing the height of a soft reservoir. Height of the reservoir is changed electrically. When the right ventricular and/or respiratory function is recovering well, the right atrial uptake cannula is clamped, and the biventricular bypass is converted gradually to left univentricular support without oxygenation. In contrast, when the left ventricular function is thought to have recovered, the left uptake cannula is clamped, and the circuit is converted to right ventricular support with cannulation of a pulmonary artery if necessary. When the biventricular support is converted to uni-
TABLE 5. Rates of weaning and dischurge in early und later periods Weaned
Discharged -
Period
Total
Number (%)
Number (%)
19841989 I 990- I995
9 8
5 (56) 7 (88)
5 (63)
3 (33)
No significant difference was noted
ventricular support, an atrial drainage cannula is clamped gradually to maintain the hemodynamic stability. The hemofiltration circuit is also combined to remove excessive water, sodium, potassium, and other metabolites because patients with cardiac failure frequently have acute renal failure. A centrifugal pump is used primarily in this circuit because it causes less blood damage than a roller pump (10,ll). The activated clotting time is maintained between 250% and 300% with an intravenous infusion of heparin. Duration of the support was significantly longer in the unweaned group than in the weaned group. The support duration was reduced in the most recent 6 years (1990-1995) from that in the earlier 6 years (1984-1989). The weaning and discharge rates showed some improvement in the most recent 6 years. In the weaned patients, mean support time was 11.3 h in the discharged group and 31.0 h in the undischarged group, but this difference was not significant. In the unweaned group, the cause of death was related to profound biventricular failure in all patients. In the weaned group, the cause of death was multiple organ failure in 3 patients and deterioration of congestive heart failure in 1 patient who had been weaned from the circulatory support 4 months earlier. In this series, no patient has survived who was supported for more than 60 h. Actually, in our experience, one of the ventricles tended to recover within 24 h. Longer circulatory support tended to increase the risk of complications: bleeding, organ damage, and infection. One p
I
< 0.05
42f.11.8 0
11.8k 6.9 TABLE 4. Duration of support in the weaned group :o . o,
H 0
Discharged patients (n = 8) Patients who died (n = 4)
11.3 ? 6.0 31.0 i 12.8
Values are expressed as the mean 2 SE; no significant difference was noted. Arrf Orgnns, V d 20, N U . 6 , 1996
€
n-8
1984 -1 989 1990 -1995 FIG. 3. The duration of circulatory support is compared for the earlier and later periods of use at the Heart Institute of Japan.
POSTCARDIOTOM Y VENTRICULAR FAILURE
I
'7
3 '0O L0
-----
1
2
0
.
9
%
3 4
'years
FIG. 4. The actuarial survival rate is illustrated for discharged patients and all patients.
of the factors in shortening the duration of circulatory support is continuous evaluation of both ventricles with transesophageal echocardiography which helps in determining the timing of weaning from the circulatory support. The time interval between the end of initial CPB and the start of BVB was significantly shorter in the successfully weaned group than in the unweaned group. Early application of the circulatory support might correlate with good results. In the operating room, i t is feasible (to some degree) to apply various circulatory support systems. In contrast, after the patient is transferred to an intensive care unit, it is difficult to introduce BVB. Percutaneous cardiopulmonary support might be applied in the case of acute deterioration in the intensive care unit and later conversion to the BVB considered. As previously mentioned, complications such as profound heart failure, bleeding, and infection remain the major problems during circulatory support. Massive bleeding can be reduced by completion of hemostasis, careful management of the activated clotting time, and early conversion to univentricular support without oxygenation. Risk of infection decreases by reduction of the duration of support. For continuous ventricular failure under the BVB, early application of more advanced circulatory support, such as pulsatile ventricular assist devices (12), may be needed for successful recovery of the function of both ventricles.
CONCLUSIONS Biventricular bypass with oxygenation was effective as a circulatory support for postcardiotomy TABLE 6. Time interval from the end of initial CPB to the introduction of biventricular support H Weaned patients (n = 12) Unweaned patients (n = 5 )
TABLE 7. Causes of death
survival rate in discharged group 66.7% survival rate of all patients
2.85 -+ 1.8 15.8 2 7.5
Values are expressed as the mean 2 SE; p < 0.05.
727
Unweaned Weaned patients who died Discharged
Heart failure
Multiple organ failure
5
-
1
3
1"
-
This patient died of ventricular arrhythmia resulting in heart failure.
ventricular failure. Early application and timely weaning from biventricular bypass may be key factors in successful circulatory support.
REFERENCES I . Kitamura M, Hirota J, Niinami H , Nishida H, Endo M, Hashimoto A, Koyanagi H . Mechanical circulatory support for postcardiotomy ventricular failure: the Heart Institute of Japan experience 1984-1992. Artif Organs 1993;17:897-900. 2. Kitamura M, Kodera K, Katsumata T, Aomi S, Hachida M, Nishida H , Endo M, Hashimoto A , Koyanagi H . Current strategy of circulatory support for profound heart failure. J Curdiovasc Surg 1995;36:71-4. 3. Pae WE, Miller CA, Matthews Y , Pierce WS. Ventricular assist devices for postcardiotomy cardiogenic shock. J Thorac Cardiovasc Surg 1992;10454 1-53. 4. Koyanagi H , Kitamura N , Kudoh T , Kurosawa H , Hiratsuka H , Konno S . Clinical application of transseptal biventricular bypass. J p n J Artif Organs 1974;3:273. 5 . Eishi K, Nishida H, Imamura E, Endo M, Hashimoto A, Koyanagi H , Soejima K, lmai Y.Circulation following open heart operation: use of the new double ventricular bypass system in preparation for switch to left ventricular bypass. J p n J Artif Organs 1987;16(1):126-9. 6 . Fonger JD, Zhou Y , Matsuura H, Aldea GS, Shemin RJ. Enhanced preservation of acutely ischemic myocardium with transseptal left ventricular assist. Ann Thoruc Surg 1994;57(3):570-5. 7. Philips SJ, Zeff RH, Kongtahworn C , Grignon A, Barker L , Iannone LA, Tnannenbaum M, Verhey MH, Wickemeyer WJ, Ghali MG, Gordon DF. Benefits of combined balloon pumping and percutaneous cardiopulmonary bypass. Ann Thorac Surg 1992 $4: 908-1 0. 8. Pennington DG, Merjavy JP, Swartz MT, Codd JE, Barner HB, Lagunoff D, Bashiti H , Kaiser GC, Willman VL. The importance of biventricular failure in patients with postoperative cardiogenic shock. Ann Thorac Surg 1985;39:16-26. 9. Aufiero TX. Combined registry (ASAIO-ISHLT) for the clinical use of mechanical ventricular assist pumps and the total artificial heart. 40th Annual Meeting of American Society for Artificial Internal Organs, San Francisco, California, April 14-16, 1994. 10. Park SB, Liebler GA, Burkholder JA, Maher TD, Benckart DH, Magovern GJ Jr, Christlieb IY, Kao RL, Magovern GJ Sr. Mechanical support for the failing heart. Ann Thorac Surg 1986;42:627-31. 11. Curtis JJ, Walls JT, Schmaltz R, Boley TM, Nawarawong W, Landreneau RJ. Experience with the Sarns centrifugal pump in postcardiotomy ventricular failure. J Thorac Cardiovasc Surg 1992;104:5 5 4 6 0 . 12. Kormos RL, Murali S, Dew MA, Armitage JM, Hardesty RL, Borovetz HS, Griffith BP. Chronic mechanical support: rehabilitation, low morbidity, and superior survival. Ann Thorac Surg 1994;57:51-8. Artif Organs, Vol. 20, N o . 6, 1996
20(6):724-727. Blackwell Science. Inc., Boston 0 1996 International Society for Artificial Organs
Biventricular Bypass with Oxygenation for Postcardiotomy Ventricular Failure Kohjiro Kodera, Masaya Kitamura, Mitsuhiro Hachida, Masahiro Endo, Akimasa Hashimoto, and Hitoshi Koyanagi Department of Cardiovascular Surgery, The Heart Institute of Japan, Tokyo Women’s Mtdicul College, Tokyo, Jupun
Abstract: Between January 1984 and March 1995, biventricular bypass (BVB) with oxygenation was used in 17 patients for postcardiotomy ventricular failure at the Heart Institute of Japan, Tokyo Women’s Medical College. Of the 17 patients, 12 (70.6%)were weaned from the circulatory support, and 8 (47.1%) were discharged from the hospital. The time interval from the end of cardiopulmonary bypass to the start of BVB was significantly shorter in weaned patients than in unweaned patients. The duration on support also has been shortened signifi-
cantly in the last 6 years, compared with the earlier 6 years. Causes of death were severe heart failure or ventricular arrhythmia in 6 patients and multiple organ failure in 3 patients. These results suggest that early application and timely weaning from biventricular bypass with OXYgenation might be the effective circulatory support of choice for treatment of postcardiotomy ventricular failure. Key Words: Biventricular bypass-Circulatory support-Postcardiotomy ventricular failure.
In recent years, standard open heart operations with effective myocardial protection have been performed successfully at many medical centers. However, approximately 1% of patients after cardiac operations have shown severe heart failure or cardiogenic shock (1-3’). We have developed and used a biventricular bypass (BVB) circuit (43) with oxygenation clinically for the treatment of postcardiotomy ventricular failure. The purpose of this study is the evaluation of clinical results of BVB for postcardiotomy ventricular failure at our institution.
of these patients were men, and 6 (35.3%) were women. The age of patients ranged from 22 to 64 years, and the mean age was 41.4 years. Fourteen of the patients had valvular heart disease, and 3 had coronary artery disease. Surgical procedures in this series of patients were aortic valve replacement in 6 cases, mitral valve replacement in 5, aortomitral double-valve replacement in 3, and coronary artery bypass grafting in 3 (Table 1). Description of the biventricular bypass A diagram of our BVB circuit is shown in Fig. 1 (4-6). This system consists of a centrifugal pump (BioMedicus, Inc., Eden Prairie, Minnesota, U .S.A.) or a roller pump, right and left atrial drainage cannulae, aortic cannula, and a membrane oxygenator. A right atrial cannula is placed through the right atrial appendage. A left atrial cannula is inserted through the right upper pulmonary vein or the left atrial appendage. An aortic cannula is placed in the ascending aorta or the femoral artery. Drainage flow is autoregulated according to the pressure of the right and left atria, thus offering appropriate circulatory support for bilateral ventricular failure. The BVB circuit is converted easily to univentricular bypass by clamping the right or left atrial can-
PATIENTS AND METHODS Patients From January 1984 to March 1995, 17 patients with postcardiotomy ventricular failure were supported using BVB at the Heart Institute of Japan, Tokyo Women’s Medical College. Eleven (64.7%) Received January 1996. Address correspondence to Dr. Kohjiro Kodera, Department of Cardiovascular Surgery, The Heart Institute of Japan, Tokyo Women’s Medical College, 8- I Kawada-cho, Shinjuku-ku, Tokyo 162, Japan.
724
POSTCARDIOTOMY VENTRICULAR FAILURE
725
TABLE 1. Surgical procedures and patients Procedure (total patients)
Male
Female
AVR (6) MVR ( 5 ) DVR (3) CABG (3) Total (17)
I
AVR, aortic valve replacement; MVR, mitral valve replacement; DVR, aortomitral double valve replacement; CABG, coronary artery bypass grafting.
nula, depending on the recovery of either ventricle's function. A hard reservoir is placed to reinfuse the suctioned blood in the early postoperative period. After complete hemostasis, this hard reservoir is not necessary. The indication for clinical use of this system is thought to be poor ventricular function (peak arterial pressure, less than 90 mm Hg; pulmonary capillary wedge pressure, more than 18 mm Hg; cardiac index, less than 1.8 L/min/m2) and/or a fatal ventricular arrhythmia despite use of a maximal dose of isotropic supports and intraaortic balloon pumping (IABP) (1,2,7,8). RESULTS
Overall weaning and discharge rates are shown in Fig. 2 and Table 2. Twelve of 17 patients could be weaned from the circulatory support with a weaning rate of 70.6%. Of these 12 patients, 8 were discharged from the hospital for an overall discharge rate of 47.1%. Five patients could not be weaned from circulatory support, and the cause of death was thought to be profound heart failure in all 5 cases. Four patients died after weaning from the circulatory support. Of these 4 patients, 3 died of multiple organ failure, and 1 died of recurrent congestive heart failure on the 140th postoperative day. Tables 3 and 4 show the duration on the circulatory support. In all cases, the duration of support in from RA to Aorta
I
from LA
Suction
I
I Weaned: 70.6% Total: 17 patients
FIG. 2. The overall rates of weaning and discharge are shown.
unweaned patients (51.6 rf: 9.3 h) was significantly longer than that in the weaned patients (17.9 & 6.2 h). Of the weaned patients, those who died tended to have a longer duration of support (31.0 -+ 12.8 h) than did the discharged patients (11.3 ? 6.0 h). In addition, the duration of support, weaning, and discharge rates were compared for early (19841989) and late (1990-1995) periods (Table 5). The duration of support was significantly shorter in the late period (Fig. 3). In the late period, the weaning and discharge rates showed some trend toward higher percentages than those in the early period. Table 6 shows the time interval from the end of initial CPB and the introduction of BVB. In the weaned group, it was significantly shorter (2.85 2 1.8 h) than in the unweaned group (15.8 rf: 7.5 h). The long-term actuarial survival proportion is shown in Fig. 4. One of the discharged patients died of ventricular arrhythmia in the long-term period (Table 7). The survival rate at 5 years, including early deaths, was 30.9%; however, in the group of discharged patients, the 5-year survival was 66.7%. DISCUSSION
According to the 1994 Report of the International Combined Registry (9), 42.6% (204 of 479) of patients receiving biventricular assistance were weaned from the support, and 23.0% (110 of 479) were discharged from the hospital. In the present study of 17 patients at the Heart Institute of Japan, 70.6% of the TABLE 2. Overall weaning and discharged rates
Procedure
Patients
Weaned
Discharged
Number (%)
Number (%)
FIG. 1. A diagram of the BVB circuit is shown. Note that the height of the soft reservoir changes electrically. Artif Organs. Vol. 20, N o . 6, 1996
K . KODERA ET A L .
726
TABLE 3. Support duration in all cases H
Weaned patients (n = 12) Unweaned patients (n = 5) Values are expressed as the mean
17.9 2 6.2 51.6 19.3
*
k
SE; p < 0.05.
patients could be weaned from circulatory support, and 47.1% were discharged from the hospital. Eightythree percent (14 of 17) of the patients with BVB had valvular heart disease, and the other patients (3 of 17) had ischemic heart disease. Postcardiotomy patients having valvular heart disease frequently show biventricular failure. In contrast, left ventricular support was used for 8 (72.7%) of 1 1 patients with severe cardiac failure after coronary artery bypass grafting (CABG) during the same period because the majority of the patients with ischemic heart disease had isolated left ventricular failure. Our BVB set-up was reported originally in 1974 (4), and it has been used clinically at our institution since then. In emergency acute cardiac failure, it is often difficult to know which particular ventricular function is impaired. As reported by Pennington et al. (8), management of biventricular failure in the early postoperative period is important. We usually use the BVB circuit in patients who may have biventricular failure with or without respiratory insufficiency. The BVB circuit consists of a blood pump, right and left atrial drainage cannulae, aortic cannula, and a membrane oxygenator. The distinguishing characteristic of this circuit is a Y-configured drainage unit. Drainage blood flow is regulated automatically according to left and right atrial pressures and is controlled by changing the height of a soft reservoir. Height of the reservoir is changed electrically. When the right ventricular and/or respiratory function is recovering well, the right atrial uptake cannula is clamped, and the biventricular bypass is converted gradually to left univentricular support without oxygenation. In contrast, when the left ventricular function is thought to have recovered, the left uptake cannula is clamped, and the circuit is converted to right ventricular support with cannulation of a pulmonary artery if necessary. When the biventricular support is converted to uni-
TABLE 5. Rates of weaning and dischurge in early und later periods Weaned
Discharged -
Period
Total
Number (%)
Number (%)
19841989 I 990- I995
9 8
5 (56) 7 (88)
5 (63)
3 (33)
No significant difference was noted
ventricular support, an atrial drainage cannula is clamped gradually to maintain the hemodynamic stability. The hemofiltration circuit is also combined to remove excessive water, sodium, potassium, and other metabolites because patients with cardiac failure frequently have acute renal failure. A centrifugal pump is used primarily in this circuit because it causes less blood damage than a roller pump (10,ll). The activated clotting time is maintained between 250% and 300% with an intravenous infusion of heparin. Duration of the support was significantly longer in the unweaned group than in the weaned group. The support duration was reduced in the most recent 6 years (1990-1995) from that in the earlier 6 years (1984-1989). The weaning and discharge rates showed some improvement in the most recent 6 years. In the weaned patients, mean support time was 11.3 h in the discharged group and 31.0 h in the undischarged group, but this difference was not significant. In the unweaned group, the cause of death was related to profound biventricular failure in all patients. In the weaned group, the cause of death was multiple organ failure in 3 patients and deterioration of congestive heart failure in 1 patient who had been weaned from the circulatory support 4 months earlier. In this series, no patient has survived who was supported for more than 60 h. Actually, in our experience, one of the ventricles tended to recover within 24 h. Longer circulatory support tended to increase the risk of complications: bleeding, organ damage, and infection. One p
I
< 0.05
42f.11.8 0
11.8k 6.9 TABLE 4. Duration of support in the weaned group :o . o,
H 0
Discharged patients (n = 8) Patients who died (n = 4)
11.3 ? 6.0 31.0 i 12.8
Values are expressed as the mean 2 SE; no significant difference was noted. Arrf Orgnns, V d 20, N U . 6 , 1996
€
n-8
1984 -1 989 1990 -1995 FIG. 3. The duration of circulatory support is compared for the earlier and later periods of use at the Heart Institute of Japan.
POSTCARDIOTOM Y VENTRICULAR FAILURE
I
'7
3 '0O L0
-----
1
2
0
.
9
%
3 4
'years
FIG. 4. The actuarial survival rate is illustrated for discharged patients and all patients.
of the factors in shortening the duration of circulatory support is continuous evaluation of both ventricles with transesophageal echocardiography which helps in determining the timing of weaning from the circulatory support. The time interval between the end of initial CPB and the start of BVB was significantly shorter in the successfully weaned group than in the unweaned group. Early application of the circulatory support might correlate with good results. In the operating room, i t is feasible (to some degree) to apply various circulatory support systems. In contrast, after the patient is transferred to an intensive care unit, it is difficult to introduce BVB. Percutaneous cardiopulmonary support might be applied in the case of acute deterioration in the intensive care unit and later conversion to the BVB considered. As previously mentioned, complications such as profound heart failure, bleeding, and infection remain the major problems during circulatory support. Massive bleeding can be reduced by completion of hemostasis, careful management of the activated clotting time, and early conversion to univentricular support without oxygenation. Risk of infection decreases by reduction of the duration of support. For continuous ventricular failure under the BVB, early application of more advanced circulatory support, such as pulsatile ventricular assist devices (12), may be needed for successful recovery of the function of both ventricles.
CONCLUSIONS Biventricular bypass with oxygenation was effective as a circulatory support for postcardiotomy TABLE 6. Time interval from the end of initial CPB to the introduction of biventricular support H Weaned patients (n = 12) Unweaned patients (n = 5 )
TABLE 7. Causes of death
survival rate in discharged group 66.7% survival rate of all patients
2.85 -+ 1.8 15.8 2 7.5
Values are expressed as the mean 2 SE; p < 0.05.
727
Unweaned Weaned patients who died Discharged
Heart failure
Multiple organ failure
5
-
1
3
1"
-
This patient died of ventricular arrhythmia resulting in heart failure.
ventricular failure. Early application and timely weaning from biventricular bypass may be key factors in successful circulatory support.
REFERENCES I . Kitamura M, Hirota J, Niinami H , Nishida H, Endo M, Hashimoto A, Koyanagi H . Mechanical circulatory support for postcardiotomy ventricular failure: the Heart Institute of Japan experience 1984-1992. Artif Organs 1993;17:897-900. 2. Kitamura M, Kodera K, Katsumata T, Aomi S, Hachida M, Nishida H , Endo M, Hashimoto A , Koyanagi H . Current strategy of circulatory support for profound heart failure. J Curdiovasc Surg 1995;36:71-4. 3. Pae WE, Miller CA, Matthews Y , Pierce WS. Ventricular assist devices for postcardiotomy cardiogenic shock. J Thorac Cardiovasc Surg 1992;10454 1-53. 4. Koyanagi H , Kitamura N , Kudoh T , Kurosawa H , Hiratsuka H , Konno S . Clinical application of transseptal biventricular bypass. J p n J Artif Organs 1974;3:273. 5 . Eishi K, Nishida H, Imamura E, Endo M, Hashimoto A, Koyanagi H , Soejima K, lmai Y.Circulation following open heart operation: use of the new double ventricular bypass system in preparation for switch to left ventricular bypass. J p n J Artif Organs 1987;16(1):126-9. 6 . Fonger JD, Zhou Y , Matsuura H, Aldea GS, Shemin RJ. Enhanced preservation of acutely ischemic myocardium with transseptal left ventricular assist. Ann Thoruc Surg 1994;57(3):570-5. 7. Philips SJ, Zeff RH, Kongtahworn C , Grignon A, Barker L , Iannone LA, Tnannenbaum M, Verhey MH, Wickemeyer WJ, Ghali MG, Gordon DF. Benefits of combined balloon pumping and percutaneous cardiopulmonary bypass. Ann Thorac Surg 1992 $4: 908-1 0. 8. Pennington DG, Merjavy JP, Swartz MT, Codd JE, Barner HB, Lagunoff D, Bashiti H , Kaiser GC, Willman VL. The importance of biventricular failure in patients with postoperative cardiogenic shock. Ann Thorac Surg 1985;39:16-26. 9. Aufiero TX. Combined registry (ASAIO-ISHLT) for the clinical use of mechanical ventricular assist pumps and the total artificial heart. 40th Annual Meeting of American Society for Artificial Internal Organs, San Francisco, California, April 14-16, 1994. 10. Park SB, Liebler GA, Burkholder JA, Maher TD, Benckart DH, Magovern GJ Jr, Christlieb IY, Kao RL, Magovern GJ Sr. Mechanical support for the failing heart. Ann Thorac Surg 1986;42:627-31. 11. Curtis JJ, Walls JT, Schmaltz R, Boley TM, Nawarawong W, Landreneau RJ. Experience with the Sarns centrifugal pump in postcardiotomy ventricular failure. J Thorac Cardiovasc Surg 1992;104:5 5 4 6 0 . 12. Kormos RL, Murali S, Dew MA, Armitage JM, Hardesty RL, Borovetz HS, Griffith BP. Chronic mechanical support: rehabilitation, low morbidity, and superior survival. Ann Thorac Surg 1994;57:51-8. Artif Organs, Vol. 20, N o . 6, 1996
