Long-term Outcome after repair of Transposition of the Great Arteries with Aortic Arch Obstruction.

BACKGROUND: This study compares the long-term outcomes of patients after repair of Transposition of the great arteries (TGA) with and without aortic arch obstruction (AAO). METHODS: This is a single-institution, retrospective study between October 2004 and February 2023. Patients who underwent arterial switch operation and aortic arch repair with patch augmentation (ASO-AAR group) were compared with those without AAO (ASO group). The primary endpoint was survival; freedom from reintervention was a secondary endpoint. RESULTS: We identified 176 patients, 31 in the ASO-AAR group and 145 in the ASO group. The median follow-up period was 10.3 years. There were no differences between the ASO-AAR group and the ASO group in early and late deaths (3.2% vs. 0.7% and 3.2% vs. 2.8%, respectively), or 15-year survival rates (92.6% vs. 96.2%). Surgical and catheter-based reinterventions were higher in the ASO-AAR group, involving the pulmonary arteries (41.9% vs. 4.8%, P<.001), aortic arch (16.1% vs. 0.7%, P<.001), and residual ventricular septal defects (11.4% vs. 0%, P=.05). The ASO-AAR group showed a higher prevalence of double outlet right ventricle TGA-type (61.3% vs. 4.1%, P<.001), and a lower aortopulmonary-index (0.67 vs. 1.01, P<.001). CONCLUSIONS: Patients undergoing surgical repair of TGA and AAO achieved excellent survival rates, comparable to patients with simple transposition. A higher rate of surgical and catheter-based reinterventions were observed in patients with arch obstruction and/or a low aortopulmonary-index. Aortic arch repair with patch augmentation proved to be an effective surgical technique with a low incidence of aortic reinterventions.

Optimizing Surgical Selection for Transposition With Left Ventricular Outflow Tract Obstruction.

BACKGROUND: Studies that have assessed the Rastelli and Nikaidoh operations for transposition of the great arteries (TGA) with obstructed left ventricular outflow tract obstruction (LVOTO) have not fully evaluated the anatomic drivers that may contribute to surgical selection. We present our procedural selection process for optimizing outcomes of complex TGA in the modern era. METHODS: This is a single-center, retrospective study that included pediatric patients who underwent either a Nikaidoh or Rastelli operation for the treatment of TGA-LVOTO, congenitally corrected TGA-LVOTO, or double-outlet right ventricle TGA type-LVOTO from June 2004 to June 2021. RESULTS: There were 34 patients stratified by Nikaidoh (n = 16) or Rastelli (n = 18) operation. The incidence of all postoperative complications and mortality was low, and the incidence of complications between the groups was similar. Patients were more likely to have undergone a Nikaidoh than a Rastelli if they had a pulmonary annulus >5 mm (87.5% vs 11.1%), anteriorly/posteriorly oriented great vessels (88% vs 8%), remote (80% vs 11%) or restrictive (75% vs 6%) ventricular septal defect, and right ventricular hypoplasia (50% vs 0%; all, P < .05). The resulting rates of reoperation were similar between the groups (44.0% vs 37.5%; P = .24) and largely composed of conduit replacements in the Rastelli patients and valvular repairs or replacements in the Nikaidoh group. Rates of catheter-based interventions were also similar. CONCLUSIONS: These findings suggest that for the optimal treatment of conotruncal anomalies with discordant ventriculoarterial connections, procedural selection should be based on pathoanatomic criteria that can ensure patients undergo the operation most suited to their anatomy.

Using DaSilva Cone Operation to Establish 1.5 or 2 Ventricle Circulation After Initial Single Ventricle Palliation with Starnes Procedure.

Ebstein anomaly (EA) is a congenital dysplasia of the tricuspid valve resulting in reduced right ventricular (RV) volume and tricuspid regurgitation. Severe EA in the neonatal period is associated with high mortality. The Starnes procedure (fenestrated RV exclusion) is reserved for EA patients with cardiogenic shock and has previously committed patients to single ventricle (SV) palliation. In this report, we present the results of a strategy to redirect patients utilizing the Da Silva Cone operation to achieve a 2 or 1.5 ventricle circulation. Single-center retrospective study including all consecutive cases of Da Silva Cone operation after Starnes procedure. Between 2019 and 2023, six conversions from Starnes procedure to Cone reconstruction were performed. All were critically ill before their Starnes procedure; four on extracorporeal membrane oxygenation. Two patients were successfully rerouted to a two-ventricle repair; the remainder to 1.5 ventricle circulation. RV pressure estimates showed no correlation with success. Post-Cone intensive care and hospital stays were brief, median 5 and 6 days, respectively. All are between 2.5 and 6 years old, without indications for SV palliation. There were no deaths, with follow up ranging 1 month-4 years. No repeat interventions were performed on the tricuspid valves. One subject had a surgical pulmonary valve replacement. Tricuspid regurgitation was mild in all. The Da Silva Cone operation offers successful redirection of EA patients from a SV pathway to a 1.5 or 2 ventricle pathway after Starnes procedure. The approach is feasible and durable in midterm follow-up. The decision to initially proceed with Starnes need not be an irrevocable decision to continue down a SV palliation pathway.

Pulmonary Homograft vs Handmade Polytetrafluoroethylene-Valved Conduits After the Ross Procedure.

BACKGROUND: This study aimed to longitudinally compare expanded polytetrafluoroethylene (ePTFE)-valved conduits vs pulmonary homograft (PH) conduits after right ventricular outflow tract reconstruction in the Ross procedure. METHODS: Patients undergoing a Ross procedure from June 2004 to December 2021 were identified. Echocardiographic data, catheter-based interventions, or conduit replacements, as well as time to first reintervention or replacement, were comparatively assessed between handmade ePTFE-valved conduits and PH conduits. RESULTS: A total of 90 patients were identified. The median age and weight were 13.8 years (interquartile range [IQR], 8.08-17.80 years) and 48.3 kg (IQR, 26.8-68.7 kg), respectively. There were 66% (n = 60) ePTFE-valved conduits and 33% (n = 30) PHs. The median size was 22 mm (IQR, 18-24 mm) for ePTFE-valved conduits and 25 mm (IQR, 23-26 mm) for PH conduits (P < .001). Conduit type had no differential effect in the gradient evolution or the odds of presenting with severe regurgitation in the last follow-up echocardiogram. Of the 26 first reinterventions, 81% were catheter-based interventions, without statistically significant differences between the groups (69% PH vs 83% ePTFE). The overall surgical conduit replacement rate was 15% (n = 14), and it was higher in the homograft group (30% vs 8%; P = .008). However, conduit type was not associated with an increased hazard for reintervention or reoperation after adjusting for covariates. CONCLUSIONS: Right ventricular outflow tract reconstruction using handmade ePTFE-valved conduits after a Ross procedure provides encouraging midterm results, without a differential effect in hemodynamic performance or valve function compared with PH conduits. These results are reassuring about the use of handmade valved conduits in pediatric and young adult patients. Longer follow-up of tricuspid conduits will complement valve competency assessment.

Congenital Heart Surgery Training Experiences and Perceptions Among Cardiothoracic Surgery Residents.

Interest and core training in congenital heart surgery (CHS) has not been characterized among current cardiothoracic surgical trainees. This study aimed to evaluate perceptions, interest, exposure, and experience among current trainees. A 22 question survey was distributed to all cardiothoracic surgical trainees in ACGME-accredited thoracic surgery residencies. Questions included demographics, exposure to CHS during, perceptions of, participation in and quality assessment of CHS training. There were 106 responses (20.1% response rate) of which 31 (29.0%) were female and 87 (81.3%) were cardiothoracic track. While 69 (64.5%) reported having an interest in CHS at some point during training, only 24 (22.4%) were actively pursuing CHS. All but 7 (6.5%) residents reported having easy access to congenital mentorship, with 35 (32.7%) actively participating in CHS research. Three months was the median duration of congenital rotations. Residents reported less operative participation on CHS compared to adult cardiac surgery. Several residents noted the need for earlier exposure and increased technical/operative experience as areas in need of improvement. The most cited primary influences to pursue CHS included: mentorship, breadth of pathology, and technical nature of the specialty. Lack of consistent job availability and length of additional training were reported as negative influences. Cardiothoracic residents report adequate exposure to obtain case requirements and knowledge for board examinations in CHS but highly variable operative involvement. Mentorship and early exposure remain important for those interested in CHS, while additional training time and limited job availability remain hurdles to CHS.

Anatomic Position and Durability of Polytetrafluoroethylene Conduit ≥18 mm: Single-Center Experience.

BACKGROUND: Conduit longevity after right ventricular outflow tract (RVOT) reconstruction is determined by the interaction of different factors. We evaluated the relationship between conduit anatomic position and long-term durability among ≥18 mm polytetrafluoroethylene (PTFE) conduits. METHODS: A single-institution RVOT reconstructions using a PTFE conduit ≥18 mm were identified. Catheter-based interventions or the need for conduit replacement were comparatively assessed between orthotopic vs heterotopic conduit position. Time to the first reintervention, censored by death, was compared between the groups. RESULTS: A total of 102 conduits were implanted in 99 patients, with a median age of 13.2 years (interquartile range [IQR] 8.9-17.8 years), median weight of 47 kg (IQR, 29-67 kg), and body surface area of 1.4 m2 (IQR, 1-1.7 m2). Overall, 50.9% (n = 52) of conduits were placed in an orthotopic position after the Ross procedure in congenital aortic valve abnormalities (80% [n = 36]). Tetrology of Fallot in 39% (n = 18), followed by truncus arteriosus with 33% (n = 15), were the most common in the heterotopic position. Trileaflet configuration was similar (67% vs 69%; P = .32) between the groups. Survival free from reintervention was 91% (95% CI, 79-97) and 88% (95% CI, 71-95) in the orthotopic and the heterotopic group, respectively, at 5 years, without differences in the Kaplan Meier curves (log-rank >.05). CONCLUSIONS: RVOT reconstruction with PTFE conduits ≥ 8 mm showed >90% conduit survival free from replacement in our cohort at 5 years. The anatomic position of the PTFE conduit does not seem to impact intermediate durability.

Utilization and Outcomes of the Nikaidoh, Rastelli, and REV Procedures: An Analysis of The Society of Thoracic Surgeons Congenital Heart Surgery Database.

BACKGROUND: Aortic root translocation (Nikaidoh), Rastelli, and réparation à l'etage ventriculaire (REV) are repair options for transposition of the great arteries (TGA) with ventricular septal defects and left ventricular outflow tract obstruction (VSD-LVOTO) or double outlet right ventricle TGA type (DORV-TGA). METHODS: This retrospective study using The Society of Thoracic Surgeons Congenital Heart Surgery Database evaluates surgical procedure utilization and outcomes of patients undergoing repair of TGA-VSD-LVOTO and DORV-TGA with a Nikaidoh, Rastelli, or REV procedure. RESULTS: A total of 293 patients underwent repair at 82 centers (January 2010 to June 2019). Most patients underwent a Rastelli (n = 165, 56.3%) or a Nikaidoh (n = 119, 40.6%) operation; only 3.1% (n = 9) underwent a REV. High-volume centers performed the majority of the repairs. Fewer Nikaidoh than Rastelli patients had prior cardiac operations (n = 57 [48.7%] vs n = 102 [63.0%]; P = .004). Nikaidohs had longer median cardiopulmonary bypass time (227 [interquartile range (IQR), 167-299] minutes vs 175 [IQR, 133-225] minutes; P < .001) and median aortic cross-clamp times (131 [IQR, 91-175] minutes vs 105 [IQR, 82-141] minutes; P = .0015). Operative mortality was 3.1% (95% confidence interval [CI], 1.0%-7.0%; n = 5) for Rastelli, 4.4% (95% CI, 1.4%-9.9%; n = 5) for Nikaidoh, and 11.1% (95% CI, 0.3%-48.3%, n = 1) for REV. The rates of cardiac arrest, unplanned reoperation, mechanical circulatory support, prolonged ventilation, and permanent pacemaker placement were higher in the Nikaidoh population but with 95% CIs overlapping those of the other procedures. CONCLUSIONS: Rastelli and Nikaidoh procedures are the prevalent repair strategies for patients with DORV-TGA and TGA-VSD-LVOTO. Most are performed at high-volume institutions, and early outcomes are similar.

Association Between Hyperoxemia and Increased Cell-Free Plasma Hemoglobin During Cardiopulmonary Bypass in Infants and Children.

OBJECTIVES: To determine potential risk factors for severe hemolysis during pediatric cardiopulmonary bypass and examine whether supraphysiologic levels of oxygen and cardiopulmonary bypass duration are associated with hemolysis. DESIGN: Prospective observational study. SETTING: Cardiac ICU in a university-affiliated children's hospital. PATIENTS: Greater than 1 month to less than 18 years old patients undergoing cardiopulmonary bypass for cardiac surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Plasma samples from 100 patients to assess cell-free plasma hemoglobin levels were obtained at start cardiopulmonary bypass, at the end of cardiopulmonary bypass, and 2 and 24 hours after reperfusion. Arterial blood gas samples were obtained before and every 30 minutes during cardiopulmonary bypass. Patient demographics and laboratory data were collected from the electronic medical record. Plasma hemoglobin levels peaked at the end of cardiopulmonary bypass and haptoglobin levels continued to fall throughout all time points. There were 44 patients with severe hemolysis (change in cell-free plasma hemoglobin > 50 mg/dL). Younger age (odds ratio/sd 0.45 [95% CI, 0.25-0.81]) and higher mean Pao2 × cardiopulmonary bypass duration (31.11 [1.46-664.64]) were identified as risk factors for severe hemolysis in multivariable analysis. Severe hemolysis was associated with longer hospital and ICU lengths of stay as well as acute kidney injury. CONCLUSIONS: We observed younger age and the exposure to both oxygen and duration of cardiopulmonary bypass as risk factors for hemolysis. Oxygen delivery through the cardiopulmonary bypass circuit is an easily modifiable risk factor. Its role in the production of reactive oxygen species that could alter the erythrocyte membrane deserves further examination in larger prospective studies.

High Risk Status for Stage I Palliation Increases Mortality After Stage II But Not Stage III.

BACKGROUND: High risk (HR) factors have been shown to have increased rates of mortality after stage 1 palliation (S1P) for single ventricle physiology. It remains unclear how initial HR status affects longitudinal outcomes after subsequent stage 2 palliation (S2P) and stage 3 palliation (S3P). METHODS: Single ventricle patients undergoing S1P between July 2004 and October 2018 at a single institution were included. Patients having one or more HR factors were considered to have HR status, with all others classified as low risk (LR). Longitudinal survival stratified by risk status was compared after each palliative stage, in addition to readmission and length of stay. Proportional hazards modeling was used to determine risk factors for longitudinal mortality. RESULTS: Of 132 patients presenting during the study for S1P, 57 (43.2%) were classified as HR. Overall 10-year survival was decreased in the HR cohort (P = .001). The HR patients were at significantly increased risk of death during interstage I (P = .01) and interstage II (P = .01), but survival was similar to that of LR patients after S3P (P = .31). Readmission rates after S2P were higher among HR patients (41.9% vs 22.5%, P = .029), but were similar after S3P. Length of stay was increased in the HR cohort after S2P (median 11 vs 9 days, P = .024) but similar to the LR group after S3P. Prematurity was the risk factor most consistently associated with increased mortality after all stages. CONCLUSIONS: A high risk status of patients undergoing S1P portends a higher risk of mortality, length of stay, and readmission after S2P. High-risk patients have survival similar to that of low-risk patients after S3P.

A High-Fidelity Percutaneous Model Used to Demonstrate ECMO Cannulation.

Medical simulation provides a realistic environment for practitioners to experience a planned clinical event in a controlled educational setting. We established a simulation model composed of synthetic ballistic gelatin that provided an inexpensive high-fidelity model for our extracorporeal membrane oxygenation (ECMO) team members to develop, master, and maintain clinical skills necessary for percutaneous cervical or femoral cannulation. The simulation component includes a cervical torso or femoral percutaneous synthetic gelatin model that is attached to either a static fluid model or to the high-fidelity perfusion simulator. Either model can be accessed with ultrasound guidance, cannulated with appropriately sized cannula, and connected to an in situ ECMO circuit. This article explains how the model is made and connected to the simulator with the purpose of re-creating this high-fidelity experience at any institution.

Design and rationale of a clinical trial to increase cardiomyocyte division in infants with tetralogy of Fallot.

BACKGROUND: Patients with Tetralogy of Fallot with pulmonary stenosis (ToF/PS), the most common form of cyanotic congenital heart disease (CHD), develop adverse right ventricular (RV) remodeling, leading to late heart failure and arrhythmia. We recently demonstrated that overactive ß-adrenergic receptor signaling inhibits cardiomyocyte division in ToF/PS infants, providing a conceptual basis for the hypothesis that treatment with the ß-adrenergic receptor blocker, propranolol, early in life would increase cardiomyocyte division. No data are available in ToF/PS infants on the efficacy of propranolol as a possible novel therapeutic option to increase cardiomyocyte division and potentially reduce adverse RV remodeling. METHODS: Using a randomized, double-blind, placebo-controlled trial, we will evaluate the effect of propranolol administration on reactivating cardiomyocyte proliferation to prevent adverse RV remodeling in 40 infants with ToF/PS. Propranolol administration (1 mg/kg po QID) will begin at 1 month of age and last until surgical repair. The primary endpoint is cardiomyocyte division, quantified after 15N-thymidine administration with Multi-isotope Imaging Mass Spectrometry (MIMS) analysis of resected myocardial specimens. The secondary endpoints are changes in RV myocardial and cardiomyocyte hypertrophy. CONCLUSION: This trial will be the first study in humans to assess whether cardiomyocyte proliferation can be pharmacologically increased. If successful, the results could introduce a paradigm shift in the management of patients with ToF/PS from a purely surgical approach, to synergistic medical and surgical management. It will provide the basis for future multi-center randomized controlled trials of propranolol administration in infants with ToF/PS and other types of CHD with RV hypertension. CLINICAL TRIAL REGISTRATION: The trial protocol was registered at clinicaltrials.gov (NCT04713657).

Polytetrafluoroethylene Tricuspid Valved Conduit for Right Ventricular Outflow Tract Reconstruction.

The ideal conduit for reconstruction of the right ventricular outflow tract in pediatric patients remains a topic of discussion. We present a technique for construction of a handmade tricuspid valved polytetrafluoroethylene conduit for use in patients of all ages requiring right ventricular outflow tract reconstruction at the time of congenital cardiac surgery. This conduit provides an economically advantageous and readily available option globally when compared with homograft, without sacrificing surgical results.

A Risk Score for Adults With Congenital Heart Disease Undergoing Heart Transplantation.

BACKGROUND: This study derived and validated a risk score for 1-year mortality in patients with adult congenital heart disease (ACHD) undergoing orthotopic heart transplantation (OHT). METHODS: The United Network for Organ Sharing registry identified patients with ACHD (≥18 years of age) who underwent OHT between 1987 and 2018. The primary outcome was 1-year mortality. Associated covariates (univariate P < .2) were entered into a multivariable logistic regression model. Variable inclusion in the model was assessed by improvement in the McFadden pseudo-R2, likelihood ratio test, and C-index. A risk score was created using the absolute magnitude of the odds ratios from the derivation cohort, and its ability to predict 1-year mortality was tested in the validation cohort. RESULTS: A total of 1388 recipients were randomly divided into derivation (66.7%, n = 950) and validation (33.3%, n = 438) cohorts. A 13-point risk score incorporating 4 pretransplant variables (age, dialysis dependence, serum bilirubin level, and mechanical ventilation) was created. The predicted 1-year mortality ranged from 14.6% (0 points) to 49.9% (13 points) (P < .001). In weighted regression analysis, there was a strong correlation between predicted 1-year mortality and observed 1-year mortality in the validation cohort (r = 0.85, P < .001). Logistic regression also demonstrated a significant association (odds ratio, 1.18; 95% confidence interval, 1.1-1.3; P = .004). The Brier score of the composite score in the validation cohort was 0.14. Kaplan-Meier analysis demonstrated that risk scores of 4 points or higher portended worse survival at 1-year posttransplant (P < .001). CONCLUSIONS: This 13-point risk score for ACHD is predictive of mortality within 1 year after OHT and has potential utilization in improving recipient selection for OHT in adult patients with CHD.

Bidirectional Glenn Procedure in Patients Less Than 3 Months of Age: A 14-Year Experience.

BACKGROUND: Contradictory data exist regarding timing of stage 2 palliation (S2P). Prolonged interstage hospitalizations and home surveillance programs have contributed to a more rapid progression to S2P. Our goal is to describe the S2P population and explore the relationships of clinical outcomes and S2P timing at our institution over the last 14 years. METHODS: S2P procedures from 2004 to 2018 at a single institution were included in a retrospective analysis. The analysis was stratified by S2P timing and clinical variables. The primary outcome was Fontan completion, and secondary outcomes included mortality and orthotopic heart transplantation rate, as well as perioperative clinical variables. RESULTS: A total of 114 patients who underwent S2P were included. The median age and weight at S2P were 100 days (interquartile range [IQR], 87-119) and 5.1 (IQR, 4.6-5.5) kg, respectively. The median age in the early group was 79 (IQR, 73-87) days and in the nonearly group was 107 (IQR, 100-124) days. Ninety percent of cavopulmonary anastomoses were augmented with an ePTFE (expanded polytetrafluoroethylene) patch. The overall Fontan completion rate was 76%, without differences in Kaplan-Meier estimates. There were no operative mortalities and no differences in late mortality rate (P = .30). CONCLUSIONS: The interstage period continues to be high risk for those undergoing single-ventricle palliation. In our experience, S2P performed at less than 90 days seems to be a viable and safe procedure when indicated, resulting in comparable Fontan completion rates.

Early experience with the HeartMate 3 continuous-flow ventricular assist device in pediatric patients and patients with congenital heart disease: A multicenter registry analysis.

BACKGROUND: The HeartMate 3 ventricular assist device (VAD) is a newer centrifugal continuous-flow VAD used for bridge-to-transplant and destination therapy in adults. However, there is limited experience regarding its use in children and adults with complex congenital heart disease (CHD). METHODS: The Advanced Cardiac Therapies Improving Outcomes Network (ACTION) is a multicenter learning network comprised of pediatric hospitals implanting VADs in children and adults with complex CHD. We examined the outcomes of patients undergoing HeartMate 3 implantation at an ACTION center between December 2017 and September 2019. RESULTS: The HeartMate 3 was implanted in 35 patients at 9 ACTION centers, with a median age of 15.7 (8.8-47.3) years, median weight of 65.7 (19.1-114.1) kg, and median body surface area (BSA) of 1.74 (0.78-2.36) m2. Of the cohort, 14 patients (40%) weighed <60 kg. Diagnoses included dilated cardiomyopathy (63%), dilated cardiomyopathy in neuromuscular disease (20%), and CHD (17%). Of those with CHD, most had a Fontan circulation. With a median 78 days of follow-up, there was 1 death on device (97% survival); 20 out of 35 (57%) underwent transplantation with no post-transplantation mortality. There were no episodes of stroke or pump thrombosis. CONCLUSIONS: Use of the HeartMate 3 in ACTION centers was associated with a low incidence of mortality and adverse events. Patients as small as 19 kg (BSA 0.78 m2) were successfully implanted and supported, indicating that this device may be appropriate for older children and small adults.

Impact of Circuit Size on Coagulation and Hemolysis Complications in Pediatric Extracorporeal Membrane Oxygenation.

Extracorporeal membrane oxygenation (ECMO) circuit volume, patient size, and blood flow may influence coagulation and hemolysis complications. We performed a single-center retrospective analysis of ECMO patients over a 6.5 year period. In 299 ECMO runs, 13% required coagulation-associated circuit changes. Respiratory ECMO was associated with coagulation-associated circuit changes [odds ratio (O/R) 2.8, p < 0.05] and developed severe (plasma-free hemoglobin [pfHb] > 100 mg/dl) hemolysis (O/R 2.3, p < 0.05). Severe hemolysis and component changes were associated with hospital mortality (O/R 2.3 and 2.5, respectively, p < 0.05). The activated partial thromboplastin time (aPTT) to residence time (RT) ratio (aPTT/RT) was used as a surrogate for coagulation risk. We found that aPTT/RT > 2.5 more than doubled time to circuit change (3-8 days, p < 0.05), but aPTT/RT > 3 increased bleeding risks and hospital mortality (O/R 1.8; p < 0.1). Hemolysis was associated with patient weight and circuit to patient volume ratio (CPVR) (p < 0.05), but not pump type. Hemolysis slightly increased with transfusion (p = 0.08), and transfusion requirements increased for CPVR >50% (p < 0.1).Our data suggest that pediatric respiratory ECMO patients are more likely to develop coagulation and hemolysis complications, which are associated with increased mortality. This may result from higher inflammatory processes, which affect coagulation and red cell fragility. Minimizing circuit volume, inflammation, and red cell stress may help to reduce these two complications and their associated mortality.