Preliminary in-silico analysis of vascular graft implantation configuration and surface modification.

Vascular grafts are used to reconstruct congenital cardiac anomalies, redirect flow, and offer vascular access. Donor tissue, synthetic, or more recently tissue-engineered vascular grafts each carry limitations spanning compatibility, availability, durability and cost. Synthetic and tissue-engineered grafts offer the advantage of design optimization using in-silico or in-vitro modeling techniques. We focus on an in-silico parametric study to evaluate implantation configuration alternatives and surface finishing impact of a novel silicon-lined vascular graft. The model consists of a synthetic 3D-generic model of a graft connecting the internal carotid artery to the jugular vein. The flow is assumed unsteady, incompressible, and blood is modeled as a non-Newtonian fluid. A comparison of detached eddy turbulence and laminar modeling to determine the required accuracy needed found mild differences mainly dictated by the roughness level. The conduit walls are modeled as non-compliant and fixed. The shunt configurations considered, are straight and curved with varied surface roughness. Following a grid convergence study, two shunt configurations are analyzed to better understand flow distribution, peak shear locations, stagnation regions and eddy formation. The curved shunt was found to have lower peak and mean wall-shear stress, while resulting in lower flow power system and decreased power loss across the graft. The curved smooth surface shunt shows lower peak and mean wall-shear stress and lower power loss when compared to the straight shunt.

A dynamic Norwood mortality estimation: Characterizing individual, updated, predicted mortality trajectories after the Norwood operation.

Objective: Post-Norwood mortality remains high and unpredictable. Current models for mortality do not incorporate interstage events. We sought to determine the association of time-related interstage events, along with (pre)operative characteristics, with death post-Norwood and subsequently predict individual mortality. Methods: From the Congenital Heart Surgeons' Society Critical Left Heart Obstruction cohort, 360 neonates underwent Norwood operations from 2005 to 2016. Risk of death post-Norwood was modeled using a novel application of parametric hazard analysis, in which baseline and operative characteristics and time-related adverse events, procedures, and repeated weight and arterial oxygen saturation measurements were considered. Individual predicted mortality trajectories that dynamically update (increase or decrease) over time were derived and plotted. Results: After the Norwood, 282 patients (78%) progressed to stage 2 palliation, 60 patients (17%) died, 5 patients (1%) underwent heart transplantation, and 13 patients (4%) were alive without transitioning to another end point. In total, 3052 postoperative events occurred and 963 measures of weight and oxygen saturation were obtained. Risk factors for death included resuscitated cardiac arrest, moderate or greater atrioventricular valve regurgitation, intracranial hemorrhage/stroke, sepsis, lower longitudinal oxygen saturation, readmission, smaller baseline aortic diameter, smaller baseline mitral valve z-score, and lower longitudinal weight. Each patient's predicted mortality trajectory varied as risk factors occurred over time. Groups with qualitatively similar mortality trajectories were noted. Conclusions: Risk of death post-Norwood is dynamic and most frequently associated with time-related postoperative events and measures, rather than baseline characteristics. Dynamic predicted mortality trajectories for individuals and their visualization represent a paradigm shift from population-derived insights to precision medicine at the patient level.

Outcomes Following Norwood Procedures: Analysis of a "Small Volume" Program.

BACKGROUND: Institutional survival following Norwood procedures is traditionally correlated with a center's surgical volume. Multiple single and multi-institutional studies conducted at large-volume centers have recently demonstrated improved survival following Norwood procedures. We report both short- and long-term outcomes at a single, small-volume institution and comment on factors potentially influencing outcomes at this institution. METHODS: All patients undergoing Norwood procedures from January 1, 2005, to January 1, 2020, at our institution were included in this study. Kaplan-Meier survival and Cox regression risk factor analyses were performed in addition to first interstage risk factor scoring to compare observed versus expected survival. RESULTS: The cohort included 113 patients. Kaplan-Meier freedom from death or transplant was 88%, 80%, and 76% at 1, 5, and 10 years, respectively. Freedom from death following hospital discharge after Norwood procedures was 94%, 87%, and 83% at 1, 5, and 10 years, respectively. The presence of genetic syndromes was a significant risk factor for mortality. First interstage observed-to-expected mortality following discharge was 0.57 (P = .04). Postoperative length of stay was comparable to that reported for the period 2015 to 2018 in the Society of Thoracic Surgeons Database. CONCLUSIONS: Survival outcomes at this single, small-volume institution were similar to those reported by large-volume centers and multi-institutional collaborative studies. These results may be related to structural and functional features that have been demonstrated to influence outcomes in other studies. These factors are achievable by small-volume programs with sufficient resource allocation.

Passive Peritoneal Drainage Impact on Fluid Balance and Inflammatory Mediators: A Randomized Pilot Study.

BACKGROUND: Infants after cardiopulmonary bypass are exposed to increasing inflammatory mediator release and are at risk of developing fluid overload. The aim of this pilot study was to evaluate the impact of passive peritoneal drainage on achieving negative fluid balance and its ability to dispose of inflammatory cytokines. METHODS: From September 2014 to November 2016, infants undergoing STAT category 3, 4, and 5 operations were randomized to receive or not receive intraoperative prophylactic peritoneal drain. We analyzed time to negative fluid balance and perioperative variables for each group. Pro- and anti-inflammatory cytokines were measured from serum and peritoneal fluid in the passive peritoneal drainage group and serum in the control group postoperatively. RESULTS: Infants were randomized to prophylactic passive peritoneal drain group (n = 13) and control (n = 12). The groups were not significantly different in pre- and postoperative peak lactate levels, postoperative length of stay, and mortality. Peritoneal drain patients reached time to negative fluid balance at a median of 1.42 days (interquartile range [IQR]: 1.00-2.91), whereas the control at 3.08 (IQR: 1.67-3.88; P = .043). Peritoneal drain patients had lower diuretic index at 72 hours, median of 2.86 (IQR: 1.21-4.94) versus 6.27 (IQR: 4.75-11.11; P = .006). Consistently, tumor necrosis factor-α, interleukin (IL)-4, IL-6, IL-8, IL-10, and interferon-γ were present at higher levels in peritoneal fluid than serum at 24 and 72 hours. However, serum cytokine levels in peritoneal drain and control group, at 24 and 72 hours postoperatively, did not differ significantly. CONCLUSIONS: The prophylactic passive peritoneal drain patients reached negative fluid balance earlier and used less diuretic in early postoperative period. The serum cytokine levels did not differ significantly between groups at 24 and 72 hours postoperatively. However, there was no significant difference in mortality and postoperative length of stay.

Pulmonary artery banding in complete atrioventricular septal defect.

OBJECTIVES: To analyze outcomes after pulmonary artery banding (PAB) in complete atrioventricular septal defect (AVSD), with a focus on surgical pathway outcome and timing, survival, and atrioventricular valve function. METHODS: PAB was performed in 50 of 474 infants (11%) from 28 institutions between 2012 and 2018 at a median age of 1.1 months. The median duration of follow-up was 2.1 years. Atrioventricular valve function was assessed by review of pre-PAB and predischarge echocardiograms (median, 9 days postoperatively). Competing-risks methodology was used to analyze the risks for biventricular repair, univentricular repair, and death. RESULTS: At 2 years, the proportions of patients who underwent biventricular repair, univentricular repair, and death were 68%, 13%, and 12%, respectively, with 8% awaiting definitive repair. After PAB, atrioventricular valve regurgitation decreased in 14 infants and increased in 10, but the distribution of regurgitation severity did not change significantly in the total cohort or subgroups. The intended management plan at PAB was deferred biventricular/univentricular decision (23 infants), 2-stage biventricular repair (24 infants), and univentricular repair (3 infants). Among the 24 infants intended for biventricular repair, 23 achieved biventricular repair and 1 died before repair. Survival at 4 years after biventricular repair among patients with previous PAB (93%) was similar to the 4-year survival of the patients who underwent primary biventricular repair (91%; n = 333). CONCLUSIONS: PAB is a successful strategy in complete AVSD to bridge to biventricular repair and has similar post-biventricular repair survival to primary biventricular repair. Changes in atrioventricular valve regurgitation after PAB were variable.

Gravity Venous Drainage and the 3/8-Inch Venous Line: What Would Poiseuille Do?

The 1/2″ venous line has long been the drainage tubing diameter of choice for adult patients undergoing cardiac surgery. However, several programs use a smaller diameter venous line when used in conjunction with kinetic-assisted venous drainage or vacuum-assisted venous drainage. In 2014, our perfusion team made an institution-wide effort to miniaturize the cardiopulmonary bypass (CPB) circuit for children. One of our changes was the transition to a 3/8″ diameter venous line for drainage, even in our larger patients (up to 80 kg). We reviewed the current literature on this topic and delineated the various parameters required to be able to use the 3/8″ venous line with gravity drainage with the aim of using it on patients up to 115 kg with the appropriate venous reservoir. We have successfully used the 3/8″ venous line in more than 40 of our larger patients (35-90 kg) without the need for assisted venous drainage. We were able to reduce CPB prime from 625 ± 118 to 425 ± 52 mL before retrograde autologous priming (RAP)/venous autologous priming (VAP). The prime was further reduced to 325 ± 66 mL after RAP/VAP. Homologous blood utilization was reduced from 217 ± 311 mL to 27 ± 77 mL. Both results were statistically significant. We hypothesize that taking into account two of the parameters of Poiseuille's law, namely length and diameter, it is possible to safely drain large children and mid-size adults via gravity venous drainage and the 3/8″ venous line. This technique allows reducing prime volume, simplifies CPB circuits with increased safety and potentially reduces the need for homologous blood transfusion.

The Congenital Heart Surgeon's Society Complete Atrioventricular Septal Defect Cohort: Baseline, Preintervention Echocardiographic Characteristics.

Quantifying unbalance, the threshold for single ventricle palliation vs biventricular repair in patients with unbalanced complete atrioventricular septal defect (AVSD), is challenging. Using a core laboratory review of baseline echocardiograms, we sought to assess the correlations among commonly used measures of unbalance and common atrioventricular valve (AVV) and ventricular sizes. A single reviewer evaluated baseline echocardiograms from an inception cohort of babies age < 1 year with complete AVSD admitted to 1 of 25 Congenital Heart Surgeon's Society institutions. A standardized echo review protocol of 111 quantitative and qualitative measures was used. Descriptive statistics were computed and Pearson correlation coefficients were calculated to assess correlation among unbalance indices with valvar and ventricular dimensions. Two-hundred fifty-seven baseline echocardiograms of infants with complete AVSD were included. Median age at baseline echocardiogram was 11 days (interquartile range 1-79) and mean atrioventricular valve index was 0.45 ± 0.1. Mean right ventricle/left ventricle inflow angle was 90.2 ± 15.6° and median left ventricular inflow index was 0.46 (interquartile range 0.4-0.5). There are weak or moderate correlations between the measures of unbalance. Correlations between the measures of unbalance with common AVV leaflet or ventricular sizes are also weak to moderate, when statistically significant. Measures of unbalance in common clinical use correlate poorly, or not at all, with one another, common AVV, and ventricular dimensions. The concept of "unbalance" is difficult to define using baseline echocardiographic indices. These findings suggest that the indices may describe different morphologic and functional characteristics. Further analysis is necessary to quantify the contributions of unbalance indices to patient outcome.

A novel, data-driven conceptualization for critical left heart obstruction.

BACKGROUND: Qualitative features of aortic and mitral valvar pathology have traditionally been used to classify congenital cardiac anomalies for which the left heart structures are unable to sustain adequate systemic cardiac output. We aimed to determine if novel groups of patients with greater clinical relevance could be defined within this population of patients with critical left heart obstruction (CLHO) using a data-driven approach based on both qualitative and quantitative echocardiographic measures. METHODS: An independent standardized review of recordings from pre-intervention transthoracic echocardiograms for 651 neonates with CLHO was performed. An unsupervised cluster analysis, incorporating 136 echocardiographic measures, was used to group patients with similar characteristics. Key measures differentiating the groups were then identified. RESULTS: Based on all measures, cluster analysis linked the 651 neonates into groups of 215 (Group 1), 338 (Group 2), and 98 (Group 3) patients. Aortic valve atresia and left ventricular (LV) end diastolic volume were identified as significant variables differentiating the groups. The median LV end diastolic area was 1.35, 0.69, and 2.47 cm2 in Groups 1, 2, and 3, respectively (p < 0.0001). Aortic atresia was present in 11% (24/215), 87% (294/338), and 8% (8/98), in Groups 1, 2, and 3, respectively (p < 0.0001). Balloon aortic valvotomy was the first intervention for 9% (19/215), 2% (6/338), and 61% (60/98), respectively (p < 0.0001). For those with an initial operation, single ventricle palliation was performed in 90% (176/215), 98% (326/338), and 58% (22/38) (p < 0.0001). Overall mortality in each group was 27% (59/215), 41% (138/338), and 12% (12/98) (p < 0.0001). CONCLUSIONS: Using a data-driven approach, we conceptualized three distinct patient groups, primarily based quantitatively on baseline LV size and qualitatively by the presence of aortic valve atresia. Management strategy and overall mortality differed significantly by group. These groups roughly correspond anatomically and are analogous to multi-level LV hypoplasia, hypoplastic left heart syndrome, and critical aortic stenosis, respectively. Our analysis suggests that quantitative and qualitative assessment of left heart structures, particularly LV size and type of aortic valve pathology, may yield conceptually more internally consistent groups than a simplistic scheme limited to valvar pathology alone.

Bloodless Heart Surgery for an 11-kg Infant of the Jehovah's Witness Faith Undergoing Second Repair for Complete Atrioventricular Canal.

Bloodless pediatric cardiac surgery is the intent of most surgical centers especially in the Jehovah's Witness population where it is a desire not to administer blood products because of religious belief. It is a tremendous feat, considering that most pediatric cardiovascular prime volumes are more than 20% of the patient's estimated blood volume (EBV). We report on our bloodless strategy for a 2-year old Jehovah's Witness with trisomy 21 and complete atrioventricular canal repair, who underwent atrial septal defect and ventricular septal defect patch closure, pulmonary artery debanding, and pulmonary arterioplasty. We modified our circuit to reduce our prime volume to approximately 10% of the EBV and removed 200 mL of the patient's blood before surgery as acute normovolemic hemodilution. We did not alter our institutional standards for transfusion of blood and blood products. The post cardiopulmonary bypass (CPB) hematocrit was 30%. We conclude that bloodless CPB surgery can be performed safely in Jehovah's Witness patients with a carefully planned interdisciplinary approach.

Septal Leaflet Versus Chordal Detachment in Closure of Hard-to-Expose Ventricular Septal Defects.

BACKGROUND: Different techniques have been used for exposure of ventricular septal defect (VSD) margins when there is crowding of the VSD anatomy by tricuspid valve subvalvar apparatus. This study compared surgical outcomes for the two techniques of tricuspid valve leaflet detachment and the rarely described tricuspid valve chordal detachment for hard-to-expose VSDs. METHODS: Patients undergoing transatrial VSD repair were identified from our institutional database. Follow-up echocardiography and patient data were obtained from medical records. Between January 2005 and August 2016, 130 isolated conoventricular VSDs were repaired. Among these, 26 patients underwent leaflet detachment, 15 underwent chordal detachment, and 89 underwent regular VSD repair (reference group). RESULTS: The groups did not differ significantly in age, weight, postoperative length of stay, genetic/syndromic abnormalities, time to extubation, and left and right ventricular systolic function. The cardiopulmonary bypass and cross-clamp time were significantly longer in the leaflet detachment group than in the reference group (118 ± 28 vs 102 ± 32 minutes [p = 0.02] and 73 ± 20 vs 61 ± 23 minutes [p = 0.01], respectively). Echocardiographic follow-up was available for 87 patients at a mean of 2.6 years (range, 1 month to 11 years). Tricuspid regurgitation was rated as none or trivial in 66 (76%), mild in 20 (23%), and moderate in 1 reference group patient. There was no difference in presence of residual VSD or degree of tricuspid regurgitation among the three groups. There was no reoperation for tricuspid regurgitation. CONCLUSIONS: Tricuspid valve leaflet and chordal detachment techniques provide an equally viable and safe alternative to closure of hard-to-expose VSDs while maintaining appropriate tricuspid valve function. Their use in our series did not lead to increased tricuspid valve dysfunction at early-to-midterm echocardiographic assessment.

Risk Factors for Gastrostomy Tube Placement in Single Ventricle Patients Following The Norwood Procedure.

Neonates with single ventricle heart disease frequently experience poor oral feeding and inconsistent weight gain, often requiring gastrostomy tube (gtube) placement. We sought to identify risk factors for gtube placement in neonates following the Norwood procedure at our institution. We retrospectively reviewed multiple preoperative, operative, and postoperative variables in neonates <30 days with single ventricle heart disease following the Norwood procedure. Study outcomes included duration of mechanical ventilation, hospital length of stay (HLOS), and gtube requirement. Multivariable logistic regression was used to analyze for associated risk factors. Seventy-nine neonates were included in the study, of which 47 underwent gtube placement (59.5%). Multivariable regression analysis found vocal cord dysfunction (P = 0.001, odds ratio 1.1, 95% confidence interval 1.0-1.4) and longer duration of sedative or narcotic infusion (P = 0.01, odds ratio 1.1, 1.03-1.2) to be independently associated with the requirement for gtube among patients who underwent the Norwood procedure. There was a significant difference in HLOS (median 69 vs 33, P = 0.003) between the gtube and the no gtube groups. Univariate analysis comparing the era of surgery was performed and found a significant difference between the groups in terms of the number of gtubes placed (P = 0.02) and duration of sedative or narcotic infusion days (P = 0.038). Both were greater in the era from 2011 to 2015. In a single-institution analysis of neonates following the Norwood procedure, gtube requirement was independently associated with vocal cord dysfunction and longer duration of sedative or narcotic infusions. gtube placement was also associated with longer HLOS.

Surgical Palliation of Right Aortic Arch With an Isolated Innominate Artery From the Left Ductus Arteriosus.

A right aortic arch with an isolated left innominate artery from the left patent ductus arteriosus is a rare arch anomaly, and establishing continuity between the innominate artery and aorta can be challenging. We describe repair of this lesion in a three-week-old male using an autologous pedicle flap of ascending aorta as well as a homograft patch as the roof to recreate continuity between the aorta and left innominate artery.

Inadequate preoperative nutrition might be associated with acute kidney injury and greater illness severity postoperatively.

OBJECTIVE: Nutrition is vital for maintaining optimal cellular and organ function, particularly in neonates who undergo cardiac surgery. Achieving nutritional goals preoperatively can be challenging because of fluid restrictions, suboptimal oral intake, and concerns for inadequate gastrointestinal circulation. We examined preoperative caloric intake and its effects on postoperative course in neonates who underwent cardiac surgery. METHODS: We retrospectively reviewed records of neonates (younger than 30 days) who underwent congenital heart surgery requiring cardiopulmonary bypass from 2008 to 2014 at Arnold Palmer Hospital for Children. Data on multiple nutritional and postoperative variables were collected. Study outcomes included hospital length of stay, duration of mechanical ventilation, and acute kidney injury (AKI). RESULTS: Records of 95 neonates were reviewed. Sixty-six patients (69.5%) with a median age of 5 days did not achieve preoperative caloric goal, whereas 29 patients (30.5%) with a median age of 11 days did. Of those who achieved caloric goal, 6 (20.6%) achieved it via total parental nutrition, 9 (31.1%) with a combination of total parental nutrition and enteral feeds, and 14 (48.3%) via enteral route. There was a significant difference in peak lactate (P = .002), inotropic score (P = .02), and duration of mechanical ventilation (P = .013) between those who did and did not achieve caloric goal. In multivariable analysis we found that failure to achieve caloric goal preoperatively was independently associated with stage 2 or 3 AKI (P = .04; odds ratio, 4.48; 95% confidence interval, 1.02-19.63) and younger age at the time of surgery (P < .001; odds ratio, 0.12; 95% confidence interval, 0.04-0.33). CONCLUSIONS: Failure to achieve preoperative caloric goal might contribute to development of AKI and might be associated with greater severity of illness postoperatively.

Recurrent Laryngeal Nerve Injury and Swallowing Dysfunction in Neonatal Aortic Arch Repair.

BACKGROUND: We evaluated the incidence, clinical effect, and recovery rate of vocal cord dysfunction (VCD) and swallowing dysfunction in neonates undergoing aortic arch repair. METHODS: We retrospectively evaluated 101 neonates who underwent aortic arch reconstruction from 2008 to 2015. Direct flexible laryngoscopy was performed in 89 patients before initiation of postoperative oral feeding after Norwood (n = 63) and non-Norwood (n = 26) arch reconstruction. We defined VCD as immobility of vocal cords or their lack of coaptation and poor mobility. RESULTS: The incidence of VCD after aortic arch repair was 48% (n = 43). There was no significant difference between the VCD and non-VCD groups in postoperative length of stay, extubation failure, cardiopulmonary bypass, cross-clamp, selective cerebral perfusion time, operative death, and The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) Congenital Heart Surgery Mortality Categories. Placement of gastrostomy (p = 0.03) and documented aspiration (p = 0.01) were significantly more common in VCD patients. The incidence of VCD was 41% (n = 26) after Norwood and 65% (n = 17) after non-Norwood repairs (p = 0.06). Gastrostomy was required in 44 Norwood patients vs 9 non-Norwood patients (p = 0.004). Median length of stay was similar in Norwood patients with or without VCD (p = .28) but was significantly longer in non-Norwood patients with VCD vs those without (p = 0.002). At follow-up direct flexible laryngoscopy, VCD recovery was 74% (14 of 19) in the Norwood group and 86% (12 of 14) in the non-Norwood group. CONCLUSIONS: The incidence of VCD and swallowing dysfunction in neonates undergoing aortic arch reconstruction is high. Patients with VCD have a significantly higher incidence of gastrostomy placement and aspiration. In the Norwood population, length of stay is not associated with presence or absence of VCD. More than 70% of patients in each group who had direct flexible laryngoscopy follow-up recovered vocal cord function.

The Impact of Roller Pump vs. Centrifugal Pump on Homologous Blood Transfusion in Pediatric Cardiac Surgery.

Centrifugal pumps are considered to be less destructive to blood elements (1) when compared to roller pumps. However, their large prime volumes render them unsuitable as arterial pumps in heart lung machine (HLM) circuitry for children. In November of 2014, the circuit at Arnold Palmer Hospital, a Biomedicus BP-50 with kinetic assist venous drainage (KAVD) and 1/4″ tubing was converted to a roller pump in the arterial position with gravity drainage. Vacuum-assisted venous drainage (VAVD) was mounted on the HLM as a backup, but not used. Tubing was changed to 3/16″ in the arterial line in patients <13 kg. A retrospective study with a total of 140 patients compared patients placed on cardiopulmonary bypass (CPB) with Biomedicus centrifugal pumps and KAVD (Centrifugal Group, n = 40) to those placed on CPB with roller pumps and gravity drainage (Roller Group, n = 100). Patients requiring extra-corporeal membrane oxygenation (ECMO)/cardio-pulmonary support (CPS) or undergoing a hybrid procedure were excluded. Re-operation or circulatory arrest patients were not excluded. Prime volumes decreased by 57% from 456 ± 34 mL in the Centrifugal Group to 197 ± 34 mL in the Roller Group (p < .001). There was a corresponding increase in hematocrit (HCT) of blood primes and also on CPB. Intraoperative homologous blood transfusions also decreased 55% from 422 mL in the Centrifugal Group to 231 mL in the Roller Group (p < .001). The Society of Thoracic Surgeons--European Association for Cardio-Thoracic Surgery (STAT) categorized intubation times and hospital length of stay (LOS) for all infants showed a trend toward reduction, but was not statistically significant. Overall mortality was 5% utilizing the centrifugal configuration and 0% in the roller pump cohort. We demonstrated that the transition to roller pumps in the arterial position of the HLM considerably reduced our priming volume and formed a basis for a comprehensive blood conservation program. By maintaining higher HCTs on CPB, we were able to reduce intraoperative homologous blood transfusions.

Comparing del Nido and Conventional Cardioplegia in Infants and Neonates in Congenital Heart Surgery.

BACKGROUND: The aim of this study was to evaluate outcome measures after the use of del Nido (dN) cardioplegia compared with conventional multidose high-potassium (non-dN) cardioplegia in neonates and infants. METHODS: We retrospectively analyzed data in patients, aged younger than 1 year, undergoing cardiopulmonary bypass (CPB) from January 2012 to August 2015. We changed our cardioplegia protocol from non-dN to dN administered in a single or infrequently dosed strategy in September 2013. The outcomes of the dN group (n = 107) are compared with the non-dN group (n = 118). We analyzed variables for demographic, intraoperative, early postoperative, and discharge variables. RESULTS: The two groups were similar in age, weight, height, CPB, and cross-clamp time; preoperative and postoperative echocardiographic systolic functions; first 24-hour postoperative urine output and inotropic score; length of stay; and mortality rate. The Society of Thoracic Surgeons/European Association for Cardio-Thoracic Surgery Congenital Heart Surgery (STAT) mortality category was significantly higher in the dN group (p = 0.03). The cardioplegia dosing interval was lower for the non-dN group (p < 0.001). The volume and doses of cardioplegia per patient were significantly higher in the non-dN group (p < 0.001). In a subanalysis, when the Norwood patients were excluded from both groups, the overall STAT mortality category difference was no longer significant. The demographic, early postoperative, and discharge variables still showed no significant difference when the two groups were compared. CONCLUSIONS: Similar outcomes can be achieved with less frequent interruption of the operation and lower volume of cardioplegia when using dN cardioplegia solution compared with conventional cardioplegia. The dN cardioplegia with extended ischemic interval can be used as an alternative strategy in the neonatal and infant population during cardiac operations.

Superior Vena Cava Banding to Facilitate Unilateral Bidirectional Glenn Operation in Patients With Single Ventricle Heart Disease and Bilateral Superior Caval Veins.

Staged palliation to achieve a total cavopulmonary connection is a common treatment strategy in patients with single ventricle congenital heart disease. Patients with bilateral superior caval veins (bilateral SVC) often require the creation of bilateral superior cavopulmonary connections as part of the staged palliation, and these patients are at increased risk of morbidity. We describe a novel technique used in two patients with bilateral SVC and very small (1-2 mm) bridging vein that encouraged bridging vein growth and facilitated creation of a unilateral superior cavopulmonary connection.

Single institution experience with the Ladd's procedure in patients with heterotaxy and stage I palliated single-ventricle.

AIM: To investigate and describe our current institutional management protocol for single-ventricle patients who must undergo a Ladd's procedure. METHODS: We retrospectively reviewed the charts of all patients from January 2005 to March 2014 who were diagnosed with heterotaxy syndrome and an associated intestinal rotation anomaly who carried a cardiac diagnosis of functional single ventricle and were status post stage I palliation. A total of 8 patients with a history of stage I single-ventricle palliation underwent Ladd's procedure during this time period. We reviewed each patients chart to determine if significant intraoperative or post-operative morbidity or mortality occurred. We also described our protocolized management of these patients in the cardiac intensive care unit, which included pre-operative labs, echocardiography, milrinone infusion, as well as protocolized fluid administration and anticoagulation regimines. We also reviewed the literature to determine the reported morbidity and mortality associated with the Ladd's procedure in this particular cardiac physiology and if other institutions have reported protocolized care of these patients. RESULTS: A total of 8 patients were identified to have heterotaxy with an intestinal rotation anomaly and single-ventricle heart disease that was status post single ventricle palliation. Six of these patients were palliated with a Blaylock-Taussig shunt, one of whom underwent a Norwood procedure. The two other patients were palliated with a stent, which was placed in the ductus arteriosus. These eight patients all underwent elective Ladd's procedure at the time of gastrostomy tube placement. Per our protocol, all patients remained on aspirin prior to surgery and had no period where they were without anticoagulation. All patients remained on milrinone during and after the procedure and received fluid administration upon arrival to the cardiac intensive care unit to account for losses. All 8 patients experienced no intraoperative or post-operative complications. All patients survived to discharge. One patient presented to the emergency room two months after discharge in cardiac arrest and died due to bowel obstruction and perforation. CONCLUSION: Protocolized intensive care management may have contributed to favorable outcomes following Ladd's procedure at our institution.

Hybrid Pulmonary Artery Stenting at the Bidirectional Glenn or Fontan Operation in Patients With Single Ventricle Congenital Heart Disease.

BACKGROUND: Stenosis of the retroaortic pulmonary artery is common in patients with single ventricle heart disease. Intraoperative hybrid stenting at the bidirectional Glenn or Fontan operation can treat this lesion and avoid a complex surgical arterioplasty. METHODS: Patients who underwent intraoperative stent implantation to the retroaortic pulmonary artery during the bidirectional Glenn or Fontan operation at our center between January 2005 and July 2014 were retrospectively identified. RESULTS: Thirteen patients were included with a median weight of 8 kg (5.6-14.4 kg) and age of 6 months (4 months-3.8 years). All had undergone Norwood operation, and eight (62%) had hypoplastic left heart syndrome. Eight (62%) underwent stent placement during bidirectional Glenn and five (38%) during Fontan operation. Ten patients had one stent placed, and three had two overlapping stents. The median diameter of the stenotic vessel was 3 mm (2.0-5.5 mm) and diameter of the balloon used for stent expansion was 7 mm (5-10 mm). Two complications occurred including pulmonary hemorrhage from presumed wire perforation and left main stem bronchus compression requiring stent removal. No patient required stent intervention in the postoperative period, and all were discharged from the hospital. At a median follow-up of 1.3 years (2 months-7.1 years), six patients underwent interval dilation to account for somatic growth. CONCLUSIONS: Hybrid stenting of the retroaortic pulmonary artery at the bidirectional Glenn or Fontan operation is an effective treatment of pulmonary artery stenosis and prevents the need for a complex surgical arterioplasty.

Are We Overdiagnosing Acute Kidney Injury in Pediatric Patients Following Cardiac Surgery?

BACKGROUND: The use of two diagnostic criteria in the current literature has led to some degree of ambiguity in the precise diagnosis of acute kidney injury in pediatric patients undergoing surgery for congenital heart disease. This study aims to determine which criteria is the most accurate diagnostic indicator of acute kidney injury and determine whether the incidence is being overestimated based on the current criteria. METHODS: This retrospective study consisted of 389 patients with congenital heart disease from birth to 18 years, who underwent cardiac surgery. The statistical tests conducted were the student t test and chi-square test. Outcomes measured included hospital length of stay, duration of mechanical ventilation, and mortality. RESULTS: The incidence rate of acute kidney injury diagnosed by the pediatric Risk, Injury, Failure, Loss, and End-Stage Renal Disease (RIFLE) criterion was 56% compared to 24.4% for the Acute Kidney Injury Network criterion. The pediatric RIFLE criterion consists of the following subsets: risk, injury, failure, loss, and end-stage renal disease. Patients classified in the "risk" subset of the pediatric RIFLE criterion who failed to meet Acute Kidney Injury Network criterion were compared to patients without acute kidney injury. Comparison of intensive care unit outcomes between these groups lacked statistical significance for all variables except the duration of mechanical ventilation postoperatively. CONCLUSION: Although recent research in this field identified the pediatric RIFLE criterion as the most sensitive indicator of acute kidney injury, the results of this study suggest the pediatric RIFLE criterion overestimates acute kidney injury incidence and that the Acute Kidney Injury Network criterion is the more accurate diagnostic indicator.