Efficacy and Safety of Aprotinin in Neonatal Congenital Heart Operations

Optimizing Blood Loss and Management in Craniosynostosis Surgery: A Systematic Review of Outcomes Over the Last 40 Years

Surgical correction of craniosynostosis can involve significant blood loss. Rates of allogenic blood transfusion have been reported to approach 100%. Multiple interventions have been described to reduce blood loss and transfusion requirements. The aim of this study was to analyze various approaches over the last 4 decades to optimize blood loss and management during craniosynostosis surgery.

PRISMA guidelines for systematic reviews were followed. PubMed and Cochrane database searches identified studies analyzing approaches to minimizing blood loss or transfusion rate in craniosynostosis surgery.

Primary outcomes included rate or amount of allogenic or autologous blood transfusion, estimated blood loss (EBL), postoperative hemoglobin (Hg), or hematocrit (Hct) levels. Secondary outcomes were examined when reported.

Fifty-two studies met inclusion criteria. There was marked heterogeneity regarding design, inclusion criteria, surgical intervention, and endpoints. The majority of the studies were nonrandomized and noncomparative. Four studies analyzed erythropoietin (EPO), 6 analyzed various cell-saver (CS) technologies, 18 analyzed antifibrinolytics (tranexamic acid [TXA], aminocaproic acid [ACA], and aprotinin [APO]), 8 analyzed various alternatives, and 16 analyzed multimodal pathways & protocols. Some studies analyzed multiple approaches.

Although the majority of studies reviewed represent level III/IV evidence, several high-quality level I studies were identified and included. Level I evidence supported an improvement in blood outcomes by utilizing EPO, CS, and TXA, individually or in concert with one another. Thus, this review suggests that a multi-prong approach may be the most effective means to optimize blood loss and transfusion outcomes in craniosynostosis surgery.

Prophylactic Use of Antifibrinolytics During Pediatric Cardiac Surgery With Cardiopulmonary Bypass on Postoperative Bleeding and Transfusion: A Systematic Review and Meta-Analysis

OBJECTIVES

To determine the effect of intraoperative antifibrinolytics, including tranexamic acid (TXA), aminocaproic acid (EACA), or aprotinin, on bleeding in children undergoing cardiac surgery with cardiopulmonary bypass (CPB).

DATA SOURCES

Relevant articles were systematically searched from Ovid MEDLINE, Ovid EMBASE, CINAHL, Cochrane Library, and Web of Science to November 15, 2021.

STUDY SELECTION

Abstracts were screened, and full texts were reviewed using predetermined inclusion and exclusion criteria using the Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline.

DATA EXTRACTION

A standardized data extraction tool was used.

DATA SYNTHESIS

Sixty-eight studies including 28,735 patients were analyzed. TXA compared with placebo resulted in a mean decrease in chest tube output of 9.1 mL/kg (95% CI, 6.0-12.3 mL/kg), I2 equals to 65.2%, p value of less than 0.001, platelet requirement of 2.9 mL/kg (95% CI, 0.1-5.8 mL/kg), I2 =72.5%, p value less than 0.001 and plasma requirement of 4.0 mL/kg (95% CI, 0.6-7.2 mL/kg), I2 equals to 94.5%, p value less than0.001. Aprotinin compared with placebo resulted in a mean decrease in chest tube output of 4.3 mL/kg (2.4-6.2 mL/kg), I2 equals to 66.3%, p value of less than 0.001, platelet transfusion of 4.6 mL/kg (95% CI, 0.6-8.6 mL/kg), I2 equals to 93.6%, p value of less than 0.001, and plasma transfusion of 7.7 mL/kg (95% CI, 2.1-13.2 mL/kg), I2 equals to 95.3%, p value of less than 0.001. EACA compared with placebo resulted in a mean decrease in chest tube output of 9.2 mL/kg (2.3-21.0 mL/kg), I2 equals to 96.4%, p value of less than 0.001, RBC transfusion of 7.2 mL/kg (95% CI, 2.4-12.1 mL/kg), I2 equals to 94.5%, p value equals to 0.002, and platelet transfusion of 10.7 mL/kg (95% CI, 2.9-18.5 mL/kg), I2 equals to 0%, p value of less than 0.001. No statistical difference was observed in chest tube output when TXA was compared with aprotinin. Subgroup analysis of cyanotic patients showed a significant decrease in chest tube output, platelet requirement, and plasma requirement for patients receiving aprotinin. Overall, the quality of evidence was moderate.

CONCLUSIONS

Antifibrinolytics are effective at decreasing blood loss and blood product requirement in children undergoing cardiac surgery with CPB although the quality of evidence is only moderate.

Evaluation of postoperative renal functions and its effect on body perfusion in patients with double aortic cannulation

BACKGROUND

The optimal visceral preservation method during aortic arch reconstruction is still controversial. It has been thought that double aortic cannulation is effective. Herein, it was aimed to evaluate this technique in providing distal perfusion.

METHODS

A total of 74 patients who underwent arch reconstruction between 2011 and 2019 were included. Patients were grouped according to ventricular physiology and cannulation strategies. Group 1 were univentricle patients, and all had double aortic cannulation. Group 2 were biventricular patients. Group 2A double aortic cannulation-done and Group 2B non-double aortic cannulation were included. Lactate, urea, creatinine values, renal functions, and need for peritoneal dialysis of patients were evaluated.

RESULTS

There were no complications observed due to descending aortic cannulation in any of the patients. A delayed sternal closure and the need for peritoneal dialysis were more common in the Group 1 (p < 0.01). The preoperative and postoperative 1st- and 2nd-day lactate, urea, and creatinine values in the Group 1 were higher (p < 0.05) when compared with the Group 2A and 2B. The same values were higher in Group 2A than the Group 2B (p < 0.05).

CONCLUSION

The positive effect of double aortic cannulation on renal dysfunction could not be demonstrated. This may be associated with a <1 month of age, low weight, complex surgical procedure, and high preoperative lactate, urea, and creatinine values in patients with double aortic cannulation.

Efficacy and safety of aprotinin in paediatric cardiac surgery: A systematic review and meta-analysis

BACKGROUND

The relicensing of aprotinin in Europe and Canada has stimulated discussions on its usefulness in paediatric cardiac surgery.

OBJECTIVE

To systematically evaluate the available evidence on the efficacy and safety of aprotinin in paediatric cardiac surgery.

DESIGN

Systematic review of all randomised and observational studies comparing aprotinin with tranexamic acid, epsilon aminocaproic acid, placebo or no drug in paediatric cardiac surgery. Meta-analyses were performed on efficacy and safety outcomes.

DATA SOURCES

PubMed, Cochrane Central Register of Controlled Trials, Web of Science and Embase were searched from January 2000 to March 2021.

ELIGIBILITY CRITERIA

Studies that enrolled children under 18 years undergoing cardiac surgery with cardiopulmonary bypass.

RESULTS

Thirty-two studies enrolling a total of 63 894 paediatric cardiac procedures were included. Aprotinin significantly reduced total blood loss [mean difference -4.70 ml kg-1, 95% confidence interval (CI), -7.88 to -1.53; P = 0.004], postoperative transfusion requirements and the incidence of surgical re-exploration for bleeding [odds ratio (OR) 0.74, 95% CI, 0.56 to 0.97; P = 0.03]. Aprotinin had no effects on 30-day mortality (OR 1.02, 95% CI, 0.93 to 1.11; P = 0.73) and on other safety outcomes, except for the incidence of renal replacement therapy (RRT), which was significantly increased in patients given aprotinin (OR 1.29, 95% CI, 1.08 to 1.54; P = 0.006). Findings from observational and randomised controlled trials did not largely differ. A sub-group analysis in neonates showed that aprotinin significantly reduced packed red blood cell transfusions and the incidence of postoperative surgical re-exploration for bleeding and/or tamponade. When compared with lysine analogues, aprotinin was more effective at reducing bleeding and transfusion without increasing the risk of side effects.

CONCLUSION

This meta-analysis suggests that aprotinin is effective and well tolerated in paediatric cardiac surgery. Given the large heterogeneity of the results and the risk of selection bias in observational studies, large randomised controlled trials are warranted.

Antifibrinolytic Drugs for the Prevention of Bleeding in Pediatric Cardiac Surgery on Cardiopulmonary Bypass: A Systematic Review and Meta-analysis

BACKGROUND

Bleeding is one of the commonest complications affecting children undergoing cardiac surgery on cardiopulmonary bypass. Antifibrinolytic drugs are part of a multifaceted approach aimed at reducing bleeding, though sufficiently sized pediatric studies are sparse, and dosing algorithms are heterogeneous. Our objective was to evaluate the efficacy and safety of antifibrinolytic agents as well as the effectiveness of different dosing regimens in pediatric cardiac surgery using cardiopulmonary bypass.

METHODS

We performed a systematic review and meta-analysis evaluating randomized controlled trials published between 1980 and 2019, identified by searching the databases MEDLINE, EMBASE, PubMed, and CENTRAL. All studies investigating patients <18 years of age without underlying hematological disorders were included. The primary outcome was postoperative bleeding; secondary end points included blood product transfusion, mortality, and safety (thromboses, anaphylaxis, renal or neurological dysfunction, and seizures). Different dosing regimens were compared. Studies were dual appraised, outcomes were reported descriptively and, if appropriate, quantitatively using the Review Manager 5 (REVMAN 5) software (The Cochrane Collaboration).

RESULTS

Thirty of 209 articles were included, evaluating the following drugs versus control: aprotinin n = 14, tranexamic acid (TXA) n = 12, and epsilon-aminocaproic acid (EACA) n = 4. The number of participants per intervention group ranged from 11 to 100 (median, 25; interquartile range [IQR], 20.5) with a wide age span (mean, 13 days to 5.8 years) and weight range (mean, 3.1-26.3 kg). Methodological quality was low to moderate.All agents reduced mean 24-hour blood loss compared to control: aprotinin by 6.0 mL/kg (95% confidence interval [CI], -9.1 to -3.0; P = .0001), TXA by 9.0 mL/kg (95% CI, -11.3 to -6.8; P < .00001), and EACA by 10.5 mL/kg (95% CI, -21.1 to 0.0; P = .05). Heterogeneity was low for TXA (I2 = 29%; P = .19), moderate for aprotinin (I2 = 41%; P = .11), and high for EACA (I2 = 95%; P = <.00001). All agents also reduced 24-hour blood product transfusion. There was no clear dose-response effect for TXA nor aprotinin. Studies were underpowered to detect significant differences in mortality, thromboses, anaphylaxis, and renal or neurological dysfunction.

CONCLUSIONS

The available data demonstrate efficacy for all 3 antifibrinolytic drugs. Therefore, the agent with the most favorable safety profile should be used. As sufficient data are lacking, large comparative trials are warranted to assess the relative safety and appropriate dosing regimens in pediatrics.

Sequestration of Dexmedetomidine in Ex Vivo Cardiopulmonary Bypass Circuits

Dexmedetomidine (DEX) is a sedative used in combination with other drugs in neonates and infants undergoing cardiac surgery using cardiopulmonary bypass (CPB). This study aimed to evaluate the disposition of DEX after administration to the ex vivo CPB circuits following different bolus doses and continuous infusion of DEX, including the effect of circuit coating, temperature, and modified ultrafiltration (MUF). Cardiopulmonary bypass circuits were setup ex vivo and primed with reconstituted blood. Dexmedetomidine was administered to the circuit (as a single bolus or single bolus along with continuous infusion). The circuit was allowed to equilibrate during the first 5 minutes, blood samples were collected at multiple time points (5-240 minutes). Blood samples were processed to collect plasma and analyzed for DEX with a validated assay. The majority of DEX sequestration in ex vivo CPB circuits occurred within the first 15 minutes. The percent of DEX remained in plasma pre-MUF (16-71%) and post-MUF (22-92%) varied depending on the dose and dosing scheme. Modified ultrafiltration significantly increased the plasma concentration of DEX in 19 of 23 circuits by an average of 12.1 ± 4.25% (p < 0.05). The percent sequestration of DEX was lower in CPB circuits at lower DEX doses compared to higher doses. A combination of DEX initial loading dose and continuous infusion resulted in steady concentrations of DEX over 4 hours. At therapeutically relevant concentrations of DEX (485-1,013 pg/ml), lower sequestration was observed in ex vivo CPB circuits compared to higher doses. The sequestration of DEX to circuits should be considered to achieve the optimal concentration of DEX during CPB surgery.

Aprotinin versus tranexamic acid in children undergoing cardiac surgery: an observational study

OBJECTIVES

The upcoming release of aprotinin in paediatric cardiac surgery prompted a re-evaluation of its use in comparison to tranexamic acid (TXA) focusing on their effect on exposure to blood transfusions as well as severe postoperative morbidity or mortality.

METHODS

This retrospective study was conducted in a tertiary children hospital from 2002 to 2015. Patients receiving aprotinin (Aprotinin group: 2002-2007) were compared with those receiving TXA group (2008-2015) using propensity score analysis. Primary outcome measures were 'exposure to blood products' and 'severe postoperative morbidity or mortality'. High-risk subgroups that included neonates, complex (Risk Adjusted Classification for Congenital Heart Surgery-1 ≥ 3) and redo surgery were also analysed.

RESULTS

The study included 2157 patients, 1136 in the Aprotinin group and 1021 in the TXA group. Exposure to blood products was significantly higher in the Aprotinin group (78% vs 60%; P < 0.001) as well as in the complex and redo surgery subgroups. Incidence of mortality and/or severe morbidity was higher in the Aprotinin group (33% vs 28%; P = 0.007), as well as in the neonate group. However, cardiopulmonary bypass priming volume and intraoperative fluid balance were significantly decreased, and the use of modified ultrafiltration significantly increased in the TXA group.

CONCLUSIONS

In our population, children receiving aprotinin were more frequently transfused and were at a higher risk of developing severe postoperative morbidity or mortality than those receiving TXA. Subgroups at high risk of bleeding or inflammation did not seem to benefit from aprotinin. These differences might be explained by a safer profile of TXA, but also attributed to major changes in our patient blood management strategies over years.

The safety and efficacy of antifibrinolytic therapy in neonatal cardiac surgery

Background

Neonates undergoing open-heart surgery are particularly at risk of postoperative bleeding requiring blood transfusion. Aprotinin has attained high efficacy in reducing the requirement for a blood transfusion following a cardiopulmonary bypass, but is seldom studied in the neonatal age group. The aim of this study was to compare the efficacy and adverse effects of aprotinin and tranexamic acid in neonates undergoing open-heart surgery at a single centre.

Methods

Between October 2003 and March 2008, perioperative data of 552 consecutive neonatal patients undergoing open-heart surgery in Children’s Hospital Boston were reviewed. Among them, 177 did not receive antifibrinolytic therapy (Group A); 100 were treated with tranexamic acid only (Group B); and 275 patients received aprotinin with or without tranexamic acid (Group C). Except for antifibrinolytic therapy, the anaesthesiological and surgical protocols remained identical. Postoperative complications and in-hospital mortality were the primary study endpoints.

Results

Body weight and Risk Adjustment for Congenital Heart Surgery (RACHS-1) scores were statistically comparable among the three groups. No statistically significant differences were observed between the duration of hospitalization, chest tube drainage, reexploration for bleeding, and kidney function impairment. In Group C, less blood was transfused within 24 hours than in GroupB. Operative mortality was similar among the three groups.

Conclusion

No further risk and kidney injury were observed in the use of aprotinin in neonatal cardiac surgery, aprotinin demonstrated a reduced requirement for blood transfusion compared with tranexamic acid. Our data provide reasonable evidence that aprotinin and tranexamic acid are safe and efficacious as antifibrinolytic modalities in neonatal patients undergoing cardiac surgery.

Long-term mortality associated with acute kidney injury in children following congenital cardiac surgery

OBJECTIVE

Children undergoing congenital cardiac surgery (CCS) are at increased risk for acute kidney injury (AKI) due to a number of factors. Recent evidence suggests AKI may influence mortality beyond the immediate postoperative period and hospitalization. We sought to determine the association between renal failure and longer-term mortality in children following CCS.

METHODS

Our Study population included all patients that underwent cardiac surgery at our institution during a period of 3 years from 2004 through 2006. The primary definition of acute renal injury was based on pRIFLE using estimated creatinine clearance (pRIFLE eCCL).

RESULTS

Predictors of mortality. Age, single ventricle status, and renal failure as defined by pRIFLE stage F were associated with mortality. The hazard ratio for a patient with renal failure as defined by pRIFLE stage F was 3.82 (CI 1.89-7.75). Predictors of AKI as defined by pRIFLE. Duration of cardiopulmonary bypass (CPB) and age were the only variables associated with pRIFLE by univariate analysis. However, in the ordinal or survival model, age was the only variable associated with renal failure as defined by pRIFLE. As patient age increases from 0.30 to 3.5 years, the risks of having renal injury (pRIFLE stage I) or failure (pRIFLE stage F) decreases (OR 0.44, CI 0.21-0.94).

CONCLUSION

Mortality risk following CCS is increased in younger patients and those experiencing postoperative renal failure as defined by pRIFLE for a period of time that extends well beyond the immediate postoperative period and the time of hospitalization.

Aprotinin and transfusion requirements in pediatric craniofacial surgery

OBJECTIVE

To evaluate transfusion requirements in children receiving aprotinin during craniofacial surgery.

BACKGROUND

Pediatric craniofacial procedures may involve massive blood loss. Aprotinin may decrease perioperative blood loss and transfusion requirements.

METHODS

Patients (aged 1 month to 3 years) who had major reconstructive craniofacial surgery received intraoperative aprotinin (13 patients) or placebo (13 patients). Administered colloids and blood products were recorded.

RESULTS

Patients in the aprotinin and placebo groups had similar mean age, body weight, body surface area, operative time, and length of hospital stay. Mean volumes of total colloids (aprotinin group: 70 ± 40 ml; and placebo group: 120 ± 80 ml; P ≤ 0.05) and packed red blood cells (aprotinin group: 380 ± 90 ml; and placebo group: 550 ± 200 ml; P ≤ 0.004) were less in the aprotinin group than in the placebo group. Mean urine output during surgery was greater in the aprotinin group than in the placebo group (320 ± 200 ml vs 150 ± 70 ml, respectively; P ≤ 0.003). Mean blood urea nitrogen and serum creatinine values after surgery were similar between the groups. Complications of aprotinin included anaphylaxis (one patient) and rash (one patient); no deaths occurred.

CONCLUSIONS

Aprotinin was associated with decreased packed red blood cell transfusion requirements in children undergoing craniofacial surgery, with no renal toxicity or death. Aprotinin is no longer available for clinical use in the USA because of adverse effects in adults; re-evaluation of aprotinin is warranted for children scheduled to undergo surgery involving potentially high blood loss.

Aprotinin revisited

In 2008, we saw the withdrawal of aprotinin from the US markets after preliminary results from a large, randomized clinical trial in Canada. This drug, a potent antifibrinolytic, was used primarily in complex and/or redo cardiac surgery as an adjunct to decrease postoperative bleeding and complications. The Canadian study raised questions previously brought up in similar studies-does aprotinin increase the risk of mortality and renal failure after cardiac surgery? Recently, a re-review of the Canadian data noted flaws in the study, as well as in the interpretation of the results. The present review revisits the aprotinin controversy.