Eur J Cardiothorac Surg 2001;20:233-238
© 2001 Elsevier Science NL
Usefulness of vacuum-assisted cardiopulmonary bypass circuit for pediatric open-heart surgery in reducing homologous blood transfusion
K. Nakanishi,
T. Shichijo,
Y. Shinkawa,
S. Takeuchi,
M. Nakai,
G. Kato,
O. Oba
Department of Cardiovascular Surgery, Hiroshima City Hospital, Hiroshima, Japan
Received 10 November 2000;
received in revised form 17 April 2001;
accepted 25 April 2001.
Corresponding author. Present address: Department of Cardiovascular Surgery, Okayama University Medical School, 2-5-1 Shikata-cho, Okayama 700-8558, Japan. Tel.: +81-86-223-7151; fax: +81-86-225-7143
e-mail: koji_15{at}sannet.ne.jp
 |
Abstract
|
|---|
Objective: Open-heart surgery without homologous blood transfusion is still difficult in children because priming volume in cardiopulmonary bypass circuit results in extreme hemodilution. Vacuum-assisted cardiopulmonary bypass circuit has the benefit of improving venous return and results in lowering priming volume. We introduced vacuum-assisted cardiopulmonary bypass circuit in order to reduce priming volume for pediatric patients in March 1995. A retrospective study was made on the efficacy of vacuum-assisted circuit for pediatric open-heart surgery in reducing homologous blood transfusion. Methods: Patients weighing from 5 to 20 kg who underwent surgery between January 1991 and June 1996 were divided into two groups, group A comprised 128 patients before introduction of this circuit and group B comprised 49 patients after introduction, and their clinical course was compared. Vacuum-assisted circuit was used in 27 patients of group B. Results: The percentage of transfusion-free operations was significantly higher in group B than in group A (33.6% in group A vs. 53.1% in group B, P=0.014), and particularly this percentage in patients weighing less than 10 kg significantly increased (0% in group A vs. 42.9% in group B, P<0.01). The amount of homologous blood transfusion was significantly lower in group B than in group A (374±362 ml in group A and 212±287 ml in group B, P<0.01). The rate of complications and the duration of respiratory support did not differ between the two groups. The duration of hospital stay was lower in group B than in group A. Conclusions: The findings of this study indicate that vacuum-assisted circuit is useful for pediatric open-heart surgery in reducing homologous blood transfusion.
Key Words: Cardiopulmonary bypass • Open heart surgery • Infant • Blood transfusion
|
1. Introduction
|
|---|
The risks of homologous blood transfusion such as immunobiological disorders [1] and transmission of infections are well documented [2]. Considering the life span of children, it is most important to avoid transmission of infections related to homologous transfusion [2]. Open-heart surgery without homologous blood transfusion is commonly performed in adults, but it is still difficult in children because priming volume in cardiopulmonary bypass (CPB) circuit results in extreme hemodilution [3]. Therefore, few reports of open-heart surgery in children without homologous blood transfusion have been published [4,5], although there have been several reports on Jehovah's Witnesses [6]. Some recent reports have shown that vacuum-assisted CPB is useful for adult cardiac surgery, especially in minimally invasive cardiac surgery [7]. Vacuum-assisted CPB has the benefit of improving venous return and results in lowering priming volume. Maeda [8] reported a newly designed vacuum-assisted CPB circuit for pediatric open-heart surgery. We modified this circuit to reduce the priming volume to 350 ml and introduced this vacuum-assisted circuit for pediatric patients in March 1995. Retrospective study was made on our clinical cases in order to evaluate the efficacy of vacuum-assisted CPB system for pediatric open-heart surgery without blood transfusion.
|
2. Patients and methods
|
|---|
From January 1991 to June 1996, 177 patients weighing between 5 and 20 kg underwent cardiac surgery with CPB in our institution, excluding 14 patients of hospital deaths. Patients were divided into two groups: group A, composed of 128 patients before introduction of vacuum-assisted circuit, and group B, composed of 49 patients after introduction. We initially used this vacuum-assisted circuit in simple cases such as atrial septal defect (ASD) or ventricular septal defect (VSD) and later expanded indications for the use of vacuum-assisted circuit to complex cases. We used this vacuum-assisted circuit in 27 patients of group B. The diagnosis and patient profile of the two groups are shown in Table 1. We compared groups A and B for percentage of bloodless prime, priming volume, percentage of transfusion-free operations, amount of homologous blood transfusion, perioperative Hb, base excess (BE), respiratory support duration, hospital stay, and rate of postoperative complications.
A schematic diagram of the vacuum-assisted CPB circuit is shown in Fig. 1
. The venous reservoir and cardiotomy sucker were given negative pressure (-10 to -40 mmHg) with vacuum and not to a roller pump, and the roller pump was used for only the arterial line [8]. The extracorporeal circuit consisted of membrane oxygenator (Menox AL-2000, 4000, Kurare, Japan). The minimum internal diameter of arterial and venous tube was 6 mm. The length of arterial line and venous line were 1450 and 750 mm, respectively. The internal diameter was 10 mm and length of venous tube was 1000 mm before introduction of this circuit. The minimum priming volume was 350 ml. The minimum level of reservoir was 80 ml on CPB. This circuit included a hemofiltrator (Jostra BC60, Jostra, Germany) but not the arterial line filter. The reservoir for venous line and suction was 15 cm below the operation table.
We did not change the priming solution and the method of CPB in this study. The priming solution was 20% mannitol, 25% volume of albumin solution, dextran-40 and lactated Ringer's solution. Core body temperature decreased to 34°C in VSD or ASD cases and to 32°C in other cases such as atrioventricular septal defect or tetralogy of Fallot. A pump flow rate of 2.5 l/m2 per min was maintained. We did not use modified ultrafiltration. The cardioplegia system used was CP3 (Senko Medical Instrument Mfg. Co., Tokyo, Japan). The cardioplegic solution was glucose–insulin–potassium solution.
The blood transfusion guideline was defined as follows: when the predicted Hb was less than 6 g/dl, we added packed red cells to CPB prime. Predicted Hb was calculated according to the following empiric formula:
where EBV is patient's estimated blood volume, PV is priming volume, and CV is volume of initial crystalloid cardioplegia. EBV was calculated as body weightx80 (ml) [9]. Homologous packed red cells were transfused when the hemoglobin value dropped to less than 5 g/dl or when metabolic acidosis developed during CPB. After termination of CPB, perfusion from the circuit was hemoconcentrated by hemofiltrator and transfused in the patient. Postoperative homologous blood transfusion was given only to patients whose postoperative hemodynamics was unstable.
Cell-saving device and aprotinin were not used during operation. All patients were anesthetized, operated on and cared for by the same methods, techniques and team during this study. We used the same blood transfusion guideline in both groups. Measured blood loss during operation included surgical field suction volume plus sponge and pad weight. Postoperative blood loss through chest drainage tubes was measured for 48 h after surgery. No correction was made for hematocrit value of chest tube blood. Blood loss was expressed in milliliters per 1 kg of body weight. The alpha-stat regulation was used. When BE was less than -10 mmol/l while carbon dioxide partial pressure was within the normal range, sodium bicarbonate was given to correct acidosis [10]. The volume of sodium bicarbonate was expressed in milliliters per 1 kg of body weight.
We chose two subgroups from groups A and B for analysis to compare the vacuum-assisted procedure directly with non-vacuum-assisted procedures; subgroup C comprised 60 patients diagnosed VSD in group A and subgroup D comprised 16 patients that were diagnosed VSD and used the vacuum-assisted circuit in group B. The patient profile of the two subgroups is shown in Table 4. We compared subgroups C and D for the same parameters for comparison between groups A and B.
2.1. Statistical analysis
Continuous data were expressed as mean±standard deviation. Proportions were compared with Fisher's exact test. Continuous variables were compared using the non-parametric Mann–Whitney U-test. A P-value of less than 0.05 was regarded as significant.
|
3. Results
|
|---|
No differences were found between two groups in age, sex, CPB time, preoperative Hb, Hb before CPB, intraoperative and postoperative bleeding volume. Aortic cross-clamp time and operation time were longer in group B than group A. The number of patients of pulmonary atresia and VSD in group B was larger than group A. Diagnosis was not statistically different between the two groups except pulmonary atresia and VSD. The lowest priming volume was 500 ml in group A and 350 ml in group B. The percentage of no blood priming was significantly higher in group B than group A (56 cases, 43.8% in group A vs. 37 cases, 75.5% in group B, P<0.01). The priming volume was significantly lower in group B than group A (639.4±88.3 ml in group A vs. 576.8±219.6 ml in group B, P<0.01). The lowest body weight without homologous blood transfusion was 12 kg in group A and 6.1 kg in group B. The youngest age without blood transfusion was 2 years in group A and 7 months in group B (Table 2). The percentage of transfusion-free operations was significantly higher in group B than group A (Fig. 2a)
. Especially, the percentage of transfusion-free operations in patients weighing between 5 and 10 kg significantly increased (0/60, 0% in group A vs. 9/21, 42.9% in group B, P<0.01). However, in patients with bloodless prime, the percentage of transfusion-free operations was not statistically different between the two groups (45/56 cases, 84.9% in group A vs. 26/37 cases, 70.3% in group B, P=0.19). The amount of homologous blood transfusion was significantly lower in group B than in group A (Fig. 2b). The minimum Hb on bypass was significantly lower in group B (7.8±1. 5 g/dl vs. 7.1±1.9, P<0.01). No differences were found between the two groups in Hb on the first, seventh and 14th postoperative day (Fig. 3a)
. The lowest BE on CPB and BE at the end of operation were not statistically different between the two groups. BE of the first postoperative day was significantly higher in group B than group A (-0.3±2.8 mEq/l in group A vs. 0.9±2.2 mEq/l in group B, P=0.011) (Fig. 3b). Total volume of 8.4% sodium bicarbonate (ml)/body weight (kg) was not different between the two groups (0.22±0.76 in group A vs. 0.37±0.69 in group B, P=0.09). The mean of respiratory support was not significantly different between the two groups (1.3±2.9 days in group A vs. 1.4±1.9 days in group B, P=0.27). The mean hospital stay in group B was significantly shorter than group A (30.5±19.4 days in group A vs. 23.1±9.8 days in group B, P<0.01). The rate of complications did not differ between group A and group B (Table 3).
View larger version (25K):
[in this window]
[in a new window]
|
Fig. 2. (a) Percentage of blood transfusion-free operations in two groups. The percentage of transfusion-free operations was significantly higher in group B than in group A. (b) The amount of homologous blood transfusion in two groups. The amount of homologous blood transfusion was significantly lower in group B than in group A.
|
|
View larger version (12K):
[in this window]
[in a new window]
|
Fig. 3. (a) Time course of value of hemoglobin in two groups. Open square, group A; closed square, group B, *Significant difference between groups A and B. Preop, preoperative; CPB, cardiopulmonary bypass; pod, postoperative day. (b) Time course of value of base excess in the two groups. Open square, group A; closed square, group B. *Significant difference between groups A and B. CPB, cardiopulmonary bypass; end of op, end of operation; pod, postoperative day.
|
|
No differences were found between two subgroups in patients characteristics (Table 4). The priming volume and volume of blood transfusion were significantly lower in subgroup C than in subgroup D. The percentage of transfusion-free operations was significantly higher in subgroup D than in subgroup C. The duration of hospital stay was shorter in subgroup C than in subgroup D (Table 5). No differences were found between the two subgroups in the minimum Hb on bypass and Hb on the first, seventh and 14th postoperative day. The lowest BE on CPB and BE at the end of operation were not statistically different between the two subgroups. BE of the first postoperative day was significantly higher in subgroup D than in subgroup C (-0.4±3.1 mEq/l in subgroup C vs. 1.8±2.1 mEq/l in subgroup D, P=0.018).
|
4. Discussion
|
|---|
In adult cardiac surgery, vacuum-assisted venous drainage has become a popular technique to augment venous return to the bypass circuit [7]. It has been reported to offer benefits for adults undergoing CPB, such as improving venous return and lowering priming volume (by eliminating the need to prime the venous line). All these benefits would be of particular value in pediatric perfusion, but few reports have been published in pediatric cardiac surgery [8,11]. We introduced vacuum-assisted CPB circuit in March 1995. Vacuum-assisted circuit could reduce priming volume to 350 ml. The minimum body weight in patients without homologous blood transfusion could be lowered from 12 to 6.1 kg and the minimum age from 2 years to 7 months. The percentage of transfusion-free operations was significantly higher in group B than group A. The amount of homologous blood transfusion was significantly lower in group B than in group A. The number of patients with pulmonary atresia/VSD in group B was larger than group A. However, no differences were observed between the two groups in preoperative Hb and Hb before CPB. The different rate of patients of pulmonary atresia/VSD between the two groups is not considered to influence the results of this study. We initially used vacuum-assisted circuit only in simple cases such as ASD and VSD and expanded indication for use of this circuit to complex cases. This vacuum-assisted circuit was used in 55% of patients in group B. However, all patients were subjected to the same blood transfusion guideline and were anesthetized, operated on and cared for by the same methods, techniques and team. In patients with bloodless prime, the percentage of transfusion-free operations was not statistically different between the two groups. We chose subgroups C and D for analysis to compare the vacuum-assisted procedure directly with non-vacuum-assisted procedures in spite of the small number. The priming volume and volume of blood transfusion were significantly lower in subgroup C than in subgroup D. The percentage of transfusion-free operations was significantly higher in subgroup D than in subgroup C. We consider that vacuum-assisted circuit reduced blood transfusion requirements and increased the percentage of transfusion-free patients, especially in patients with body weight between 5 and 10 kg.
Vacuum-assisted drainage circuit could reduce the diameter and length of lines and has a potential benefit in decreasing inflammatory activation [12,13]. A decrease in inflammatory activation can improve the postoperative course [14]. The total volume of sodium bicarbonate (ml)/body weight (kg) was not different between the two groups, but BE on the first postoperative day was significantly higher in group B than in group A. It has been suggested that vacuum-assisted drainage improves peripheral vascular circulation after surgery [10]. We did not change the politics of postoperative management, but the mean hospital stay in group B was significantly shorter than in group A and the mean hospital stay in subgroup C was also shorter than in subgroup D. Further study should be made on the relationship between the inflammatory reaction of vacuum-assisted drainage circuit and the postoperative course.
In this study there was no complication related to the use of this circuit and no difference in the rate of postoperative complications between group A and group B. Vacuum-assisted drainage circuit may contribute to increased blood trauma. No differences in Hb value were found between the two groups during the postoperative period, but further examination should be made on hemolysis. Entrained venous air during vacuum-assisted venous drainage is a potential hazard [15]. In this study, patients with vacuum-assisted circuit did not show any neurological complications, though an arterial line filter was not used. Further study should be made to investigate neurocognitive deficits after using vacuum-assisted circuit.
This study demonstrated that vacuum-assisted CPB circuit was effective, simple, and safe for avoidance of blood transfusion and reduction of blood transfusion requirements in infants and children with congenital heart defects. Experimentally, vacuum-assisted venous drainage has made asanguineous prime feasible and allowed for blood transfusion requirements in neonates [16]. We propose to use vacuum-assisted CPB circuit to reduce blood transfusion requirements for neonates.
This study, being retrospective, has several limitations. All patients used the same blood transfusion guideline, but the minimum Hb on bypass in group B was significantly lower than in group A. A prospective study should made to evaluate the efficacy of vacuum-assisted CPB. Only 27 of the patients used this vacuum-assisted circuit. More experience should be accumulated on its use.
In summary, the findings of this study indicate that vacuum-assisted circuit is useful for pediatric open-heart surgery in reducing homologous blood transfusion.
|
References
|
|---|
-
Salama A., Mueller E.C. Delayed hemolytic transfusion reactions. Evidence for complement activation involving allogeneic and autologous red cells. Transfusion 1984;24:188-193.[Medline]
-
Rasenack J.W., Schlayer H.J., Hettler F., Peters T., Preisler A.S., Gerok W. Hepatitis B virus infection without immunological markers after open-heart surgery. Lancet 1995;345:355-357.[Medline]
-
Chambers L.A., Cohen D.M., Davis J.T. Transfusion patterns in pediatric open heart surgery. Transfusion 1996;36:150-154.[Medline]
-
Honek T., Horvath P., Kucera V., Kostelka M., Hucin B., Stark J. Minimization of priming volume and blood saving in paediatric cardiac surgery. Eur J Cardio-thorac Surg 1992;6:308-310.[Abstract]
-
Fukahara K., Murakami A., Ueda T., Doki Y., Tsubata S., Ichida F., Misaki T. Scheduled autologous blood donation at the time of cardiac catheterization in infants and children. J Thorac Cardiovasc Surg 1997;114:504-505.[Free Full Text]
-
Henling C.E., Carmichael M.J., Keats A.S., Cooley D.A. Cardiac operation for congenital heart disease in children of Jehovah's Witnesses. J Thorac Cardiovasc Surg 1985;89:914-920.[Abstract]
-
Hatzopoulos F.K., Stile C.I., Rodvold K.A., Sullivan B.J., Del N.P., Levitsky S. Vacuum-assisted venous drainage (VAVD). Perfusion 1999;14:419-423.[Abstract/Free Full Text]
-
Maeda M., Koyama T., Murase M., Teranishi K., Sakurai H., Nishizawa T. The indications and limitations of open heart surgery without homologous blood transfusion in children and infants. Nippon Kyobu Geka Gakkai Zasshi 1994;42:1-7.[Medline]
-
Kawashima Y., Yamamoto Z., Manabe H. Safe limits of hemodilution in cardiopulmonary bypass. Surgery 1974;76:391-397.[Medline]
-
Boldt J., Knothe C., Zickmann B., Hammermann H., Stertman W.A., Hempelmann G. Does correction of acidosis influence microcirculatory blood flow during cardiopulmonary bypass?. Br J Anaesth 1993;71:277-281.[Abstract/Free Full Text]
-
Berryessa R., Wiencek R., Jacobson J., Hollingshead D., Farmer K., Cahill G. Vacuum-assisted venous return in pediatric cardiopulmonary bypass. Perfusion 2000;15:63-67.[Abstract/Free Full Text]
-
Kirklin J.K., Westaby S., Blackstone E.H., Kirklin J.W., Chenoweth D.E., Pacifico A.D. Complement and the damaging effects of cardiopulmonary bypass. J Thorac Cardiovasc Surg 1983;86:845-857.[Abstract]
-
Steinberg B.M., Grossi E.A., Schwartz D.S., McLoughlin D.E., Aguinaga M., Bizekis C., Greenwald J., Flisser A., Spencer F.C., Galloway A.C., Colvin S.B. Heparin bonding of bypass circuits reduces cytokine release during cardiopulmonary bypass. Ann Thorac Surg 1995;60:525-529.[Abstract/Free Full Text]
-
Seghaye M.C., Duchateau J., Grabitz R.G., Faymonville M.L., Messmer B.J., Buro-Rathsmann K., von Bernuth G. Complement activation during cardiopulmonary bypass in infants and children. Relation to postoperative multiple system organ failure. J Thorac Cardiovasc Surg 1993;106:978-987.[Abstract]
-
Willcox T.W., Mitchell S.J., Gorman D.F. Venous air in the bypass circuit: a source of arterial line emboli exacerbated by vacuum-assisted drainage. Ann Thorac Surg 1999;68:1285-1289.[Abstract/Free Full Text]
-
Lau C.L., Posther K.E., Stephenson G.R., Lodge A., Lawson J.H., Darling E.M., Davis R.D., Jr, Ungerleider R.M., Jaggers J. Mini-circuit cardiopulmonary bypass with vacuum-assisted venous drainage: feasibility of an asanguineous prime in the neonate. Perfusion 1999;14:389-396.[Abstract/Free Full Text]
This article has been cited by other articles:
|
|
|
|
 
B. Marcheix, M. Carrier, C. Martel, M. Cossette, M. Pellerin, D. Bouchard, and L. P. Perrault
Effect of Pericardial Blood Processing on Postoperative Inflammation and the Complement Pathways
Ann. Thorac. Surg.,
February 1, 2008;
85(2):
530 - 535.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
K. Charette, Y. Hirata, A. Bograd, L. Mongero, J. Chen, J. Quaegebeur, and R. Mosca
180 ml and less: cardiopulmonary bypass techniques to minimize hemodilution for neonates and small infants.
Perfusion,
September 1, 2007;
22(5):
327 - 331.
[Abstract]
[PDF]
|
|
|
|
|
|
|
F. Merkle, W. Boettcher, F. Schulz, A. Koster, M. Huebler, and R. Hetzer
Perfusion technique for nonhaemic cardiopulmonary bypass prime in neonates and infants under 6 kg body weight
Perfusion,
July 1, 2004;
19(4):
229 - 237.
[Abstract]
[PDF]
|
|
|
Top
Abstract
1. Introduction
