Newborn Aortic Arch Reconstruction With Descending Aortic Cannulation Improves Postoperative Renal Function

Evaluation of end-organ protection in newborns and infants after surgery of aortic arch hypoplasia: A prospective randomized study

INTRODUCTION

Surgical repair of aortic arch hypoplasia in children requires a "dry" surgical field with reliable end-organ protection. Perfusion strategies commonly involve deep hypothermic circulatory arrest (DHCA) and variations of the continuous perfusion techniques, such as selective antegrade cerebral perfusion (SACP) and full-flow perfusion with double aortic cannulation (DAC). We aimed to evaluate the end-organ protection in the surgery of aortic arch hypoplasia in newborns and infants using DHCA and DAC.

MATERIALS AND METHODS

66 newborns and infants with aortic arch hypoplasia and biventricular anatomy were enrolled in this prospective study. Patients were randomly assigned into two groups according to the perfusion strategy - DHCA (n = 33); and DAC (n = 33). Primary endpoint: acute kidney injury (AKI), graded according to the KDIGO score. Secondary endpoints: neurological sequelae (pre- and postoperative MRI), in-hospital mortality.

RESULTS

The lowest temperature was 32 (28; 34)°С in the DAC group and 23 (20; 25)°С in the DHCA group. The patients with DAC had lower incidence of AKI (6 patients (18.2%) versus 19 patients (57.6%); p = .017). In the multivariate analysis, the inotropic index at 48 h was identified as a risk factor, increasing the risk of AKI by 4%. The DHCA group was associated with a 3.8-fold increase in the risk of AKI. There was no difference in hospital mortality between the DAC and DHCA groups (1 patient (3%) versus 3 patients (9.1%); p = .61). Neurological sequelae by MRI scan were observed in 18 patients (54.5%) in the DHCA group compared to 5 patients (15.15%) in the DAC group (p = .026). The only risk factor identified in the multivariate analysis for neurological lesions on MRI scan was the DHCA group, which increased the risk by 8.8 times.

CONCLUSIONS

Surgical reconstruction of the aortic arch hypoplasia using the method of full-body perfusion reduces the incidence of neurological lesions and renal complications requiring renal replacement therapy compared with the deep hypothermic circulatory arrest in neonates and infants.

Temperature and Neurologic Outcomes in Neonates Undergoing Cardiac Surgery: A Society of Thoracic Surgeons Study

BACKGROUND

There is significant variability in postoperative neurological injury rates in patients with congenital heart disease, with early injuries impacting long-term neurodevelopmental outcomes; therefore, there is an urgent need for identifying effective strategies to mitigate such injuries.

OBJECTIVES

This study aims to assess the association between nadir intraoperative temperature (NIT) and early neurological outcomes in neonates undergoing congenital heart surgery.

METHODS

Analyzing data from 24,345 neonatal cardiac operations from the Society for Thoracic Surgeons Congenital Heart Surgery Database between 2010 and 2019, NIT was assessed using a mixed-effect logistic regression model, targeting major neurological injury (stroke, seizure, or deficit at discharge) as a primary endpoint.

RESULTS

The study observed a shift from hypothermic circulatory arrest to cerebral perfusion with an increase in mean nadir temperature from 23.9 °C to 25.6 °C (P < 0.0001). Major neurological injury was noted in 4.9% of the cohort, with variations based on surgical procedure. After adjusting for risk, NIT was not significantly associated with major neurological injuries overall, but a lower NIT showed protective effects in the Norwood subgroup. Factors increasing the risk of major neurological injury included younger age at surgery, the Norwood procedure, longer cardiopulmonary bypass times, younger gestational age, presence of noncardiac abnormalities, and chromosomal anomalies.

CONCLUSIONS

Whereas neurological injuries are prevalent after neonatal cardiac surgery, current practices lean towards higher core temperatures. This trend is supported by the nonsignificant impact of NIT on neurological outcomes. However, lower NIT in the Norwood subgroup indicates that reduced temperatures may be beneficial amidst specific risk factors.

Abdominal and Peripheral Tissue Oxygen Supply during Selective Lower Body Perfusion for the Surgical Repair of Congenital Heart Disease: A Pilot Study

Background: Lower body perfusion (LBP) may be a strategy for maintaining organ perfusion during congenital heart disease surgery. It is hypothesized that renal and lower limb oxygen supply during LBP is superior to off-pump surgery and comparable to that of a standard cardiopulmonary bypass (CPB). Methods: in this prospective single-center study, patients aged <1 year were recruited if they were scheduled for a correction of aortic arch anomalies using antegrade cerebral perfusion and LBP (group 1), a repair of coarctation during aortic cross-clamping (group 2), or surgery under whole-body CPB (group 3). Renal (prefix “r”) and peripheral (prefix “p”) oxygen saturation (SO2), hemoglobin amount (Hb), blood velocity (Velo), and blood flow (Flow) were measured noninvasively. Results: A total of 23 patients were included (group 1, n = 9; group 2, n = 5; group 3, n = 9). Compared to the baseline values, rSO2 and pSO2 decreased significantly in group 2 compared to groups 1 and 3. Conversely, rHB significantly increased in group 2 compared to groups 1 and 3, reflecting abdominal venous stasis. Compared to group 3, group 1 showed a significantly lower pFlow during CPB; however, rFlow, pFlow, and pVelo did not differ. Conclusion: according to these observations, LBP results in an improved renal oxygen supply compared to off-pump surgery and may prove to be a promising alternative to conventional CPB.

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.

Comparison of cases with and without additional lower body perfusion in newborns undergoing aortic arch reconstruction with antegrade selective cerebral perfusion method

Background

The aim of this study was to analyze the effect of additional lower body perfusion, compared to antegrade selective cerebral perfusion, on early postoperative outcomes after aortic arch repair in neonates with biventricular morphology.

Methods

Between January 2017 and April 2020, a total of 46 neonates (34 males, 12 females; median age: 10 days; range, 7 to 14 days) with biventricular morphology underwent an aortic arch reconstruction were retrospectively analyzed. The effects of antegrade selective cerebral perfusion and additional lower body perfusion techniques on vital organ preservation and mortality were evaluated in these patients who underwent arch reconstruction.

Results

In the univariate analysis of the whole cohort, postoperative creatinine level was lower in the additional lower body perfusion group, while there was no significant difference between the other parameters. In the multivariate analysis, intraoperative highest lactate level (odds ratio: 1.7; 95% confidence interval: 1.07-2.68; p=0.02) and postoperative 4th t o 6 th h lactate levels (odds ratio: 2.34; 95% confidence interval: 1.08-5.09; p=0.03) were independent predictors of early mortality. Mortality rate was higher in the antegrade selective cerebral perfusion group (22% vs. 7%), although it did not reach statistical significance. In the receiver operating characteristic curve analysis, the cut-off value for intraoperative lactate was 6.2 mmol/L (sensitivity: 85.7%, specificity: 71.1%) and the cut-off value for the lactate level at the postoperative 4th to 6th h was 4.9 mmol/L (sensitivity: 85.7%, specificity: 73.7%). Above these lactate levels were found to be associated with mortality.

Conclusion

Additional lower body perfusion may have a role in vital organ protection in aortic arch repair of neonates, compared to antegrade selective cerebral perfusion.

Postoperative Acute Kidney Injury in Williams Syndrome Compared With Matched Controls

OBJECTIVES

Cardiovascular manifestations occur in over 80% of Williams syndrome (WS) patients and are the leading cause of morbidity and mortality. One-third of patients require cardiovascular surgery. Renal artery stenosis (RAS) is common in WS. No studies have assessed postoperative cardiac surgery-related acute kidney injury (CS-AKI) in WS. Our objectives were to assess if WS patients have higher risk of CS-AKI postoperatively than matched controls and if RAS could contribute to CS-AKI.

DESIGN

This was a retrospective study of all patients with WS who underwent cardiac surgery at our center from 2010 to 2020. The WS study cohort was compared with a group of controls matched for age, sex, weight, and surgical procedure.

SETTING

Patients underwent cardiac surgery and postoperative care at Lucile Packard Children's Hospital Stanford.

PATIENTS

There were 27 WS patients and 43 controls (31% vs 42% female; p = 0.36). Median age was 1.8 years (interquartile range [IQR], 0.7-3.8 yr) for WS and 1.7 years (IQR, 0.8-3.1 yr) for controls.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Postoperative hemodynamics, vasopressor, total volume input, diuretic administration, and urine output were collected in the first 72 hours. Laboratory studies were collected at 8-hour intervals. Multivariable analysis identified predictors of CS-AKI.Controlled for renal perfusion pressure (RPP) and vasoactive inotrope score (VIS), compared with controls, the odds ratio (OR) of CS-AKI in WS was 4.2 (95% CI, 1.1-16; p = 0.034). Higher RPP at postoperative hours 9-16 was associated with decreased OR of CS-AKI (0.88 [0.8-0.96]; p = 0.004). Increased VIS at hour 6 was associated with an increased OR of CS-AKI (1.47 [1.14-1.9]; p = 0.003). Younger age was associated with an increased OR of CS-AKI (1.9 [1.13-3.17]; p = 0.015).

CONCLUSIONS

The OR of CS-AKI is increased in pediatric patients with WS compared with controls. CS-AKI was associated with VIS at the sixth postoperative hour. Increases in RPP and mean arterial pressure were associated with decreased odds of CS-AKI.

Triple-Arterial Cannulation Approach for Whole-Body Perfusion in Infant Hypoplastic Aortic Arch and Coarctation Repair

Organ and end-organ protection in aortic arch surgery represents a substantial challenge, especially in infants. Selective antegrade cerebral perfusion has been reported to improve organ function during this procedure. Visceral perfusion can be optimized by cannulation of the descending aorta during infant aortic arch surgery, leading to a decrease in end organ damage. However, it is associated with extensive surgical manipulation and subsequent risk of major vessel and potential organ damage. In this report, we describe a technique for distal body perfusion in an infant with hypoplastic aortic arch and isthmus stenosis by ultrasound-guided cannulation of the femoral artery using an intra-arterial vascular sheath establishing whole-body perfusion by triple cannulation.

Post-operative Renal Failure, Shunt Type and Mortality after Norwood Palliation

BACKGROUND

The Single Ventricle Reconstruction (SVR) trial demonstrated increased risk of death or heart transplant one year post-Norwood in subjects randomized to Blalock-Taussig shunts (mBTS) compared to right ventricle-to-pulmonary artery (RV-PA) shunts. We used the SVR public use database to evaluate incidence and risk factors for post-operative renal failure and relationships between renal failure, shunt type and outcomes post-Norwood.

METHODS

Post-operative renal failure was defined a-priori as a 3-fold rise in creatinine from baseline, or dialysis use, within 7 days of Norwood. We used multivariate logistic regression to evaluate risk factors for post-operative renal failure and Cox hazard regression to determine the association between post-operative renal failure and one-year post-Norwood mortality.

RESULTS

Overall, post-operative renal failure occurred in 8.4% (46/544) with risk factors including receipt of a mBTS (aOR 3.3, p=0.02), low center volume (aOR 2.7, p=0.005), presence of ≥2 pre-op complications (aOR 4.0, p<0.001), low birth weight (aOR 3.2, p=0.002), post-operative heart block (aOR 8.5, p=0.001), and delayed sternal closure (aOR 5.3, p=0.026). Renal failure was an independent risk factor for one-year mortality (aHR 1.9, p=0.019). Assessing interaction by shunt type, mortality risk associated with renal failure was greatest in the RV-PA shunt group (aHR 3.3 versus RV-PA shunt without renal failure, p=0.001), but was also increased in the mBTS group (aHR 1.9, p=0.03).

CONCLUSIONS

Post-operative renal failure is common after Norwood and is independently associated with mortality. Although renal failure is more common after mBTS, the highest mortality risk with renal failure occurs after RV-PA shunt.

Low-body-perfusion via an arterial sheath reduces inflammation after aortic arch reconstruction surgery

Pediatric cardiac surgeries involving aortic arch reconstruction are complex and require long cardiopulmonary bypass (CPB) times with deep hypothermic circulatory arrest (DHCA). Selective perfusion techniques have been developed to prevent the deleterious consequences of DHCA associated hypoperfusion. The effectivity of low body perfusion through cannulation of the femoral artery with an arterial sheath remains to be elucidated. We compared perfusion and inflammation in patients receiving selective antegrade cerebral perfusion (ACP) only to low body perfusion (LBP) in addition to ACP during DHCA for aortic arch reconstruction surgery. There was no difference in patient characteristics, cardiac pathologies, or performed procedures between ACP and LBP groups. Lactate levels increased after cardiac arrest in both groups. However, lactate levels were lower after 1 h reperfusion, at the end of extracorporeal circulation (ECC), and after surgery in LBP group compared to ACP only. Furthermore, creatinine was increased in ACP group on postoperative day 1 compared to LBP group but no acute kidney injury was observed in any group. IL-6 concentration increased in ACP group, while remained unchanged in LBP group compared to pre surgical values and were significantly lower compared to ACP group on postoperative days 1 and 2. LBP via an arterial sheath during cardiac arrest for aortic arch reconstruction surgery in addition to ACP, improves post ECC tissue perfusion as indicated by lower lactate levels and reduces creatinine levels suggesting milder kidney injury. LBP seems to prevent postoperative inflammation through a reduction in procedural duration or enhanced perfusion and thereby improves the outcome after aortic arch reconstruction surgery.

Total circulatory arrest as a support modality in congenital heart surgery: review and current evidence

The use of total circulatory arrest (TCA)/deep hypothermic circulatory arrest (DHCA) as a support modality in congenital heart surgery is a time-tested strategy. However, with technological advances, the widespread use of this technique has decreased. Adjunctive cerebral perfusion with continuous cardiopulmonary bypass (CPB) gradually has become more popular with a view to reduce the complications related to DHCA. In addition, better neuromonitoring and neuroprotective strategies have made DHCA much safer. However, the level of evidence to support the best way to protect the brain during congenital heart surgery is insufficient. This review analyzes the history, physiology, techniques of DHCA, as well as other alternative strategies like selective cerebral perfusion and presents the current available evidence.

Selective lower body perfusion during aortic arch surgery in neonates and small children

Introduction:

Aortic arch reconstruction surgery represents a challenge for the medical personnel involved in treatment. Along the years, the perfusion strategies for aortic arch reconstruction have evolved from deep hypothermic cardiac arrest to antegrade cerebral perfusion with moderate hypothermia, and recently to a combined cerebral and lower body perfusion with moderate hypothermia. To achieve a lower body perfusion, several cannulation strategies have been described. In this study, we investigated the feasibility of utilizing an arterial sheath introduced in the femoral artery to achieve an effective lower body perfusion.

Methods:

We included patients who underwent an aortic arch reconstruction surgery with a lower body perfusion, from January 2017 to June 2019. To achieve a lower body perfusion, a three-way stopcock was connected to the arterial line, where one end was connected to the central cannulation for cerebral perfusion and the other to an arterial sheath that was introduced through the femoral artery. A total of 25 patients were included. Peri- and postoperative lactate and creatinine levels and signs of malperfusion were recorded.

Results:

During the reperfusion phase, after selective perfusion ended none of the patients showed a significant increase in lactate, creatinine, and liver enzyme levels. After 24 hours, there were no signs of an acute kidney injury, femoral vessel injury, or limb malperfusion.

Conclusion:

These findings show that a sufficient lower body perfusion through an arterial sheath placed in the femoral artery for aortic arch reconstruction can be achieved. This approach caused no complications related to the arterial sheath during the early postoperative period and is an easy way to maintain perfusion of systemic organs.

Selective Antegrade Cerebral Perfusion With or Without Additional Lower Body Perfusion During Aortic Arch Reconstruction in Infants

BACKGROUND

Aortic arch reconstruction is often challenging, especially in infants, owing to its high postoperative complication risks. This study aimed to compare the effectiveness between selective antegrade cerebral perfusion (SACP) alone and SACP in combination with continuous lower body perfusion with descending aortic cannulation (DAC) in preserving renal function, and to determine the influence of perfusion strategy on the postoperative course of infants who underwent aortic arch reconstruction.

MATERIAL AND METHODS

A total of 121 infants who underwent aortic arch reconstruction between January 2008 and December 2018 were included in the analysis. Patients (median age: 29 days, range: 3-270 days) were divided into the following groups: those who underwent repair with SACP (SACP group, 79 patients) and those who underwent additional lower body perfusion (DAC group, 42 patients).

RESULTS

Three (7.1%) and nine (11.4%) patients died in the DAC and SACP groups, respectively (P = .54). The SACP group had more patients requiring renal replacement therapy (P = .002) and higher incidence of second stage acute kidney injury (AKI) development (Kidney disease improving global outcomes (KDIGO) criteria; P = .032). The SACP group had higher frequency of open chest postoperatively than the DAC group (P = .011). The DAC group had lower vasoactive inotropic score (VIS) at the first postoperative day (P < .001) and shorter intensive care unit length of stay (P = .050). There was no difference in neurological complications between the groups (P = .061). High VIS was associated with early mortality (odds ratio [OR]: 1.79 [1.33-2.41], P < .001) and AKI (OR: 1.60 [1.35-1.91], P < .001). The DAC perfusion strategy with minimal hypothermia was associated with lower risk of AKI (OR: 0.91 [0.84-0.98], P = .016).

CONCLUSION

Antegrade cerebral perfusion with continuous lower body perfusion via DAC could effectively be used for improving early postoperative results among infants undergoing procedures that include aortic arch reconstruction.

Double-arterial cannulation: a strategy for whole body perfusion during aortic arch reconstruction

OBJECTIVES

Double-arterial cannulation enables cerebral perfusion and lower body perfusion during aortic arch reconstruction. The aim of this study was to analyse and report our experience of using this cannulation and perfusion technique on paediatric patients.

METHODS

A retrospective single-centre study was carried out on 407 consecutive paediatric patients who underwent an aortic arch reconstruction under double-arterial cannulation between 2003 and 2015. The median age of the patients at surgery was 8 (range 2-5570) days, and body weight was 3.3 (range 1.8-60) kg. All operations were performed through standard median sternotomy. One arterial cannula was inserted into the innominate artery and the second one into the supradiaphragmatic descending aorta. Primary end points were 30-day mortality, acute renal failure requiring dialysis and time until lactate level decreased to ≤2 mmol/l postoperatively.

RESULTS

We found an in-hospital mortality of 8.6%. Lethal incident was not associated with the cannulation method, and 1 intraoperative lesion of the descending aorta could be repaired immediately. The median lactate level of the patients on arrival at the intensive care unit was 3.5 mmol/l [quartile (Q)1: 2.3-Q3: 4.7] and creatinine was 0.48 mg/100 ml (Q1: 0.40-Q3: 0.58). The longest duration until the lactate level decreased to ≤ 2 mmol/l was found in the group of 264 univentricular patients (median 11 h, Q1: 6-Q3: 24). Seven (1.7%) patients of the whole cohort required peritoneal dialysis postoperatively.

CONCLUSIONS

Double-arterial cannulation is a simple and safe method for perfusing the brain and the lower parts of the body during aortic arch reconstruction. Perioperative survival and freedom from procedure-related complications in this demanding patient population are encouraging.

Recent achievements and future developments in neonatal cardiopulmonary bypass

A primary goal of improving neonatal cardiopulmonary bypass has been making the circuit smaller and reduce the blood contacting surfaces. As bypass circuit size has decreased, bloodless surgery has become possible even in neonates. Since transfusion guidelines are difficult to construct based on existing literature, these technical advances should be taken advantage of in conjunction with an individualized transfusion scheme, based on monitoring of oxygen availability to the tissues. For the majority of neonatal heart operations, several centers have shifted toward normothermic bypass even for complex neonatal surgeries, in order to avoid the adverse effects of hypothermia. Deep hypothermic circulatory arrest is no longer a necessity but an option, and selective antegrade cerebral perfusion has become common practice; however, technical uncertainties with regard to this technique have to be addressed, based on reliable neurologic monitoring. Maintenance of patient-specific heparin concentrations during bypass is another key goal, since neonates have lower baseline antithrombin concentrations and, therefore, a higher risk for inadequate thrombin inhibition and postoperative bleeding. Due to the immaturity of their hemostatic system, the standard coagulation tests alone are inappropriate to guide hemostatic therapy in neonates. The use of indirect heparin concentration assays and global viscoelastic assays in the operating room is likely to represent the optimal strategy, and requires validation in neonates. Monitoring of global and regional indexes of oxygen availability and consumption on bypass have become possible; however, their use in neonates still has outstanding technical issues which should be addressed and hence needs further validation. Due to the immaturity of the neonatal myocardium, single-shot cold cardioplegia solutions are thought to confer the best myocardial protection; their superiority when compared to more conventional modalities, however, remains to be demonstrated.

Recent Advances in Congenital Heart Surgery: Alternative Perfusion Strategies for Infant Aortic Arch Repair

PURPOSE OF REVIEW

This paper will discuss current cannulation strategies for infant aortic arch repair and compare them to more traditionally used techniques.

RECENT FINDINGS

Aortic arch reconstruction in infants has traditionally involved deep hypothermic circulatory arrest which results in total body ischemia. This has been associated with an increased risk of morbidity including bleeding, renal dysfunction, and neurologic injury. Advances in perfusion techniques have allowed for preserved perfusion to the brain during arch repair. Current techniques have further evolved that allow for continuous perfusion of the heart and even the lower body during arch reconstruction. With current techniques, aortic arch reconstruction in infants can be performed with continuous perfusion to the brain, heart, and lower body. Further technical refinements will be helpful, and study is necessary to evaluate the benefit of these strategies.

Selective versus standard cerebro-myocardial perfusion in neonates undergoing aortic arch repair: A multi-center study

The results of neonatal aortic arch surgery using cerebro-myocardial perfusion were analyzed. Selective cerebral and myocardial perfusion, using two separate pump rotors, was compared with standard perfusion, using a single pump rotor with an arterial line Y-connector. Between May 2008 and May 2016, 69 consecutive neonates underwent arch repair using either selective cerebro-myocardial perfusion (Group A, n = 34) or standard perfusion (Group B, n = 35). The groups were similar for age, weight, BSA, prevalence of one-stage or staged repair, and single ventricle palliation; male gender was more frequent in Group A. The duration of the cerebro-myocardial perfusion was comparable (27 ± 8 vs. 28 ± 7 min, P = 0.9), with higher flows in Group A (57 ± 27 vs. 39 ± 19 mL/kg/min, P = 0.01). Although cardioplegic arrest was more common in Group B (13/34 vs. 23/35, P = 0.03), the duration of myocardial ischemia was longer in Group A (64 ± 41 vs. 44 ± 14 min, P = 0.04). There was 1 hospital death in each group, with no permanent neurological injury in either group. Cardiac morbidity (1/34 vs. 7/35, P = 0.02) was more common in Group B, while extracardiac morbidity was similar in both the groups. During follow-up (3.2 ± 2.4 years), 5 late deaths occurred with a comparable 5-year survival rate (75 ± 17% vs. 88 ± 6%, P = 0.7) and freedom from arch reintervention (86 ± 6% vs. 84 ± 7%, P = 0.6). Risk of cardiac morbidity was greater with standard cerebro-myocardial perfusion (OR = 5.2, CI 3.3-6.8, P = 0.001) and with perfusion flows less than 50 mL/kg/min (OR 3.7, CI 1.87-5.95, P = 0.04). Cerebro-myocardial perfusion is a safe and effective strategy to protect the brain and heart in neonates undergoing arch repair. Selective techniques using higher perfusion flows may further attenuate cardiac morbidity.

Double Arterial Cannulation in the Critical Management of Neonatal Aortic Arch Obstruction With Closed Ductus Arteriosus

The neonatal management of critical aortic arch obstruction in association with an arterial duct that remains closed or significantly constricted requires urgent surgical repair, with a postoperative focus on resolving the impaired function of compromised organs. Here, we present two neonatal cases illustrating the use of the dual arterial cannulation perfusion method in the complete repair of interrupted aortic arch and critical coarctation of the aorta with nonfunctional ductus arteriosus. We suggest that dual arterial cannulation, which provides total body perfusion (with the exception of cardiac perfusion during cardioplegic arrest of the heart), may be a good alternative to other perfusion strategies in cases of absent ductal blood flow, as this method allowed us to avoid the further development of severe multiple organ failure.

Supplemental Perfusion Techniques for Aortic Arch Reconstruction, With Emphasis on Direct Cannulation of the Descending Aorta

The established techniques of deep hypothermia with circulatory arrest and regional cerebral perfusion expose infants and children to additional physiologic stress and deleterious effects which may adversely affect the outcome of operations involving reconstruction of the aortic arch. Alternative techniques to supplement perfusion support are an area of innovation today. The most effective adjunct for somatic perfusion during arch reconstruction is direct cannulation of the innominate artery and the descending aorta, with full flow at mild hypothermia distributed throughout the entire body just as it is during routine, single cannulation surgery with an intact aorta. Detailed facilitating techniques for descending aortic cannulation are discussed.

Direct Splanchnic Perfusion Safely Avoids Deep Hypothermia

Deep hypothermia for the operative correction of congenital cardiac lesions protects hypoperfused organs, mostly because of its effect on lowering metabolic demand and oxygen requirement. Deleterious cerebral and extracranial side effects of deep hypothermia itself calls for a reexamination of the therapeutic value of hypothermia, and has led to the development of alternative perfusion strategies. Here we describe the potential advantages of milder hypothermia over deep hypothermia and our method of a practical and reproducible implementation of multisite perfusion under mild hypothermia (32°C).

Selective visceral perfusion improves renal flow and hepatic function in neonatal aortic arch repair

OBJECTIVES

The aortic arch repair in the neonatal period is a complex procedure with significant morbidity. We define a useful double-perfusion technique and its effect on the function of abdominal organs in the postoperative course.

METHODS

Nine patients with double perfusion (Group 1) were compared with 14 patients with antegrade cerebral perfusion (Group 2). The objective was to discern the incidence of postoperative acute kidney injury and impaired hepatic function, as well as tissue perfusion and myocardial function parameters. Mechanical ventilation time, postoperative length of stay and 30-day mortality were measured. We excluded patients with extracorporeal membrane oxygenation, early mortality (<72 h) and preoperative renal or hepatic insufficiency.

RESULTS

Nine (39%) patients developed postoperative acute kidney injury, with 22% (n = 2) in Group 1 and 50% (n = 7) in Group 2 (P = 0.183). A higher urine output was observed during the first 24 h for Group 1 (P = 0.032). Eleven patients developed impaired hepatic function in the immediate postoperative period: 2 (18.2%) in Group 1 and 9 (81.8%) in Group 2 (P = 0.04). The international normalized ratio (P = 0.006-0.031) and prothrombin time (P = 0.007-P = 0.016) were significantly lower in the double-perfusion group during the first 72 h. Significant difference was observed in lactate levels in the first 72 h (P = 0.001-0.009). There was no postoperative mortality in either group.

CONCLUSIONS

Selective visceral perfusion is a safe procedure that provides a better urine output, hepatic function and tissue perfusion. This technique allows for the repair of complex aortic arch anomalies in neonates without deep hypothermic circulatory arrest.

Preoperative Aortic Arch Size and Late Outcome After Coarctation Repair by Lateral Thoracotomy

BACKGROUND

The approach (lateral thoracotomy versus median sternotomy) to repair coarctation of the aorta is frequently based on arch dimensions from the preoperative echocardiogram. Few studies have assessed the relationship between preoperative arch dimensions and late postoperative outcome. This study aimed to define how preoperative arch dimensions relate to late outcomes and identify long-term predictors of a successful operation.

METHODS

We performed a retrospective review of 102 neonates and infants undergoing isolated coarctation repair by lateral thoracotomy between 2003 and 2012. Long-term surgical success was defined based on the following five factors: corrected arch gradient below 20 mm Hg, blood pressure cuff gradient below 15 mm Hg, systolic blood pressure below the 95th percentile during the clinic visit, no antihypertensive medication use, and freedom from reintervention. Regression analysis was performed to identify factors that would predict the need for reintervention and long-term success.

RESULTS

At a median of 6 years of follow-up, long-term success was achieved in 63% (56 of 89) of patients, and 94% (96 of 102) were free of reintervention. Bivariate analysis showed that patients requiring reintervention had smaller absolute isthmus dimension (p = 0.04). No significant predictors for reintervention or long-term success could be identified, although a larger distal transverse arch dimension may play a role in long-term success (hazard ratio, 0.7; 95% confidence interval, 0.05 to 1.0; p = 0.06).

CONCLUSIONS

Aortic arches of various dimensions were successfully repaired by lateral thoracotomy. No significant predictors for reintervention or long-term success could be identified, although the distal transverse arch dimension may play a role in long-term success.

Recent innovations in perfusion and cardiopulmonary bypass for neonatal and infant cardiac surgery

The development and refinement of cardiopulmonary bypass (CPB) has made the repair of complex congenital heart defects possible in neonates and infants. In the past, the primary goal for these procedures was patient survival. Now that substantial survival rates have been achieved for even the most complex of repairs in these patients, focus has been given to the reduction of morbidity. Although a necessity for these complex neonatal and infant heart defect repairs, CPB can also be an important source of perioperative complications. Recent innovations have been developed to mitigate these risks and is the topic of this review. Specifically, we will discuss improvements in minimizing blood transfusions, CPB circuit design, monitoring, perfusion techniques, temperature management, and myocardial protection, and then conclude with a brief discussion of how further systematic improvements can be made in these areas.

Selective Cerebro-Myocardial Perfusion in Complex Neonatal Aortic Arch Pathology: Midterm Results

Aortic arch repair in newborns and infants has traditionally been accomplished using a period of deep hypothermic circulatory arrest. To reduce neurologic and cardiac dysfunction related to circulatory arrest and myocardial ischemia during complex aortic arch surgery, an alternative and novel strategy for cerebro-myocardial protection was recently developed, where regional low-flow perfusion is combined with controlled and independent coronary perfusion. The aim of the present retrospective study was to assess short-term and mid-term results of selective and independent cerebro-myocardial perfusion in neonatal aortic arch surgery. From April 2008 to August 2015, 28 consecutive neonates underwent aortic arch surgery under cerebro-myocardial perfusion. There were 17 male and 11 female, with median age of 15 days (3-30 days) and median body weight of 3 kg (1.6-4.2 kg), 9 (32%) of whom with low body weight (<2.5 kg). The spectrum of pathologies treated was heterogeneous and included 13 neonates having single-stage biventricular repair (46%), 7 staged biventricular repair (25%), and 8 single-ventricle repair (29%). All operations were performed under moderate hypothermia and with a "beating heart and brain." Average cardiopulmonary bypass time was 131 ± 64 min (42-310 min). A period of cardiac arrest to complete intra-cardiac repair was required in nine patients (32%), and circulatory arrest in 1 to repair total anomalous pulmonary venous connection. Average time of splanchnic ischemia during cerebro-myocardial perfusion was 30 ± 11 min (15-69 min). Renal dysfunction, requiring a period of peritoneal dialysis was observed in 10 (36%) patients, while liver dysfunction was noted only in 3 (11%). There were three (11%) early and two late deaths during a median follow-up of 2.9 years (range 6 months-7.7 years), with an actuarial survival of 82% at 7 years. At latest follow-up, no patient showed signs of cardiac or neurologic dysfunction. The present experience shows that a strategy of selective and independent cerebro-myocardial perfusion is safe, versatile, and feasible in high-risk neonates with complex congenital arch pathology. Encouraging outcomes were noted in terms of cardiac and neurological function, with limited end-organ morbidity.

Is Decellularized Porcine Small Intestine Sub-mucosa Patch Suitable for Aortic Arch Repair?

Introduction: We reviewed our experience with decellularized porcine small intestine sub-mucosa (DPSIS) patch, recently introduced for congenital heart defects. Materials and Methods: Between 10/2011 and 04/2016 a DPSIS patch was used in 51 patients, median age 1.1 months (5 days to 14.5 years), for aortic arch reconstruction (45/51 = 88.2%) or aortic coarctation repair (6/51 = 11.8%). All medical records were retrospectively reviewed, with primary endpoints interventional procedure (balloon dilatation) or surgery (DPSIS patch replacement) due to patch-related complications. Results: In a median follow-up time of 1.5 ± 1.1 years (0.6-2.3years) in 13/51 patients (25.5%) a re-intervention, percutaneous interventional procedure (5/51 = 9.8%) or re-operation (8/51 = 15.7%) was required because of obstruction in the correspondence of the DPSIS patch used to enlarge the aortic arch/isthmus, with median max velocity flow at Doppler interrogation of 4.0 ± 0.51 m/s. Two patients required surgery after failed interventional cardiology. The mean interval between DPSIS patch implantation and re-intervention (percutaneous procedure or re-operation) was 6 months (1-17 months). While there were 3 hospital deaths (3/51 = 5.9%) not related to the patch implantation, no early or late mortality occurred for the subsequent procedure required for DPSIS patch interventional cardiology or surgery. The median max velocity flow at Doppler interrogation through the aortic arch/isthmus for the patients who did not require interventional procedure or surgery was 1.7 ± 0.57 m/s. Conclusions: High incidence of re-interventions with DPSIS patch for aortic arch and/or coarctation forced us to use alternative materials (homografts and decellularized gluteraldehyde preserved bovine pericardial matrix).

Blood Versus Crystalloid Cardioplegia in Pediatric Cardiac Surgery: A Systematic Review and Meta-analysis

The benefit of blood cardioplegia (BCP) compared to crystalloid cardioplegia (CCP) is still debatable. Our aim was to systematically review and synthesize all available evidence on the use of BCP and CCP to assess if any modality provides superior outcomes in pediatric cardiac surgery. A systematic literature search of the PubMed and Cochrane databases was performed with respect to the PRISMA statement (end-of-search date: January 30th, 2017). We extracted data on study design, demographics, cardioplegia regimens, and perioperative outcomes as well as relevant biochemical markers, namely cardiac troponin I (cTnI), lactate, and ATP levels at baseline, after reperfusion and postoperatively at 1, 4, 12, and 24 h as applicable. Data were appropriately pooled using random and mixed effects models. Our systematic review includes 56 studies reporting on a total of 7711 pediatric patients. A meta-analysis of the 10 eligible studies directly comparing BCP (n = 416) to CCP (n = 281) was also performed. There was no significant difference between the two groups with regard to cTnI and Lac at any measured time point, ATP levels after reperfusion, length of intensive care unit stay (WMD: -0.08, 95% CI -1.52 to 1.36), length of hospital stay (WMD: 0.13, 95% CI -0.85 to 1.12), and 30-day mortality (OR 1.11, 95% CI 0.43-2.88). Only cTnI levels at 4 h postoperatively were significantly lower with BCP (WMD: -1.62, 95% CI -2.07 to -1.18). Based on the available data, neither cardioplegia modality seems to be superior in terms of clinical outcomes, ischemia severity, and overall functional recovery.

Current Readings on Surgery for the Neonate With Hypoplastic Aortic Arch

Aortic arch hypoplasia is commonly present in neonates born with ductal-dependent coarctation of the aorta. The ideal surgical repair of neonates with proximal arch hypoplasia continues to be debated. Controversy exists about the fate of the hypoplastic proximal aortic arch following surgical repair and whether that will eventually grow to normal size upon relief of the distal obstruction or will persist as a residual lesion that can affect the long-term outlook of those patients. There is new evidence that residual proximal arch hypoplasia and the shape of the reconstructed arch both have an important impact on vascular remodeling and on the subsequent development of hypertension. Those concerns about late outcomes despite what was originally deemed a successful repair in infancy, coupled with improved cardiopulmonary bypass and cerebral perfusion techniques that allow surgeons to address proximal arch hypoplasia with low morbidity, have rekindled the debate on how to address proximal arch hypoplasia, with the aim to offer a neonatal surgery that would last for a lifetime and provide both optimal early recovery and late freedom from hypertension and related complications.

Neonatal Aortic Arch Reconstruction With Direct Splanchnic Perfusion Avoids Deep Hypothermia

BACKGROUND

Neonatal aortic arch reconstruction, typically performed with deep hypothermia and selective cerebral perfusion, leaves splanchnic organ protection dependent on hypothermia alone. A simplified method of direct in-field descending aortic perfusion during neonatal arch reconstruction permits the avoidance of deep hypothermia. We hypothesize that direct splanchnic perfusion at mild hypothermia provides improved or equivalent safety compared with deep hypothermia and may contribute to postoperative extracardiac organ recovery.

METHODS

Included were 138 biventricular patients aged younger than 90 days undergoing aortic arch reconstruction with cardiopulmonary bypass. Patients were grouped according to perfusion method A (selective cerebral perfusion with deep hyperthermia at 18° to 20°C) or method B (selective cerebral perfusion and splanchnic perfusion at 30° to 32°C). Patient characteristics and perioperative clinical and serologic data were analyzed. Significance was assigned for p of less than 0.05.

RESULTS

Of the 138 survivors, 63 underwent method A and 75 underwent method B. The median age at operation was 8.5 days (range, 6 to 15 days), and median weight was 3.2 kg (range, 2.8 to 3.73 kg), with no significant differences between groups. Cardiopulmonary bypass times were comparable between the two perfusion methods (p = 0.255) as were the ascending aortic cross-clamp times (p = 0.737). The postoperative glomerular filtration rate was significantly different between our groups (p = 0.028 to 0.044), with method B achieving a higher glomerular filtration rate. No significant differences were seen in ventilator time, postoperative length of stay, fractional increase of postoperative serum creatinine over preoperative serum creatinine, and postoperative lactate.

CONCLUSIONS

A simplified method of direct splanchnic perfusion during neonatal aortic arch reconstruction avoids the use of deep hypothermia and provides renal protection at least as effective as deep hypothermia.

Variation in Perfusion Strategies for Neonatal and Infant Aortic Arch Repair: Contemporary Practice in the STS Congenital Heart Surgery Database

BACKGROUND

Regional cerebral perfusion (RCP) is used as an adjunct or alternative to deep hypothermic circulatory arrest (DHCA) for neonates and infants undergoing aortic arch repair. Clinical studies have not demonstrated clear superiority of either strategy, and multicenter data regarding current use of these strategies are lacking. We sought to describe the variability in contemporary practice patterns for use of these techniques.

METHODS

The Society of Thoracic Surgeons Congenital Heart Surgery Database (2010-2013) was queried to identify neonates and infants whose index operation involved aortic arch repair with cardiopulmonary bypass. Perfusion strategy was classified as isolated DHCA, RCP (with less than or equal to ten minutes of DHCA), or mixed (RCP with more than ten minutes of DHCA). Data were analyzed for the entire cohort and stratified by operation subgroups.

RESULTS

Overall, 4,523 patients (105 centers) were identified; median age seven days (interquartile range: 5.0-13.0). The most prevalent perfusion strategy was RCP (43%). Deep hypothermic circulatory arrest and mixed perfusion accounted for 32% and 16% of cases, respectively. In all, 59% of operations involved some period of RCP. Regional cerebral perfusion was the most prevalent perfusion strategy for each operation subgroup. Neither age nor weight was associated with perfusion strategy, but reoperations were less likely to use RCP (31% vs 45%, P < .001). The combined duration of RCP and DHCA in the RCP group was longer than the DHCA time in the DHCA group (45 vs 36 minutes, P < .001).

CONCLUSION

There is considerable variability in practice regarding perfusion strategies for arch repair in neonates and infants. In contemporary practice, RCP is the most prevalent perfusion strategy for these procedures. Use of DHCA is also common. Further investigation is warranted to ascertain possible relative merits of the various perfusion techniques.

Risk Factors for Acute Kidney Injury after Congenital Cardiac Surgery in Infants and Children: A Retrospective Observational Study

Acute kidney injury (AKI) after pediatric cardiac surgery is associated with high morbidity and mortality. Modifiable risk factors for postoperative AKI including perioperative anesthesia-related parameters were assessed. The authors conducted a single-center, retrospective cohort study of 220 patients (aged 10 days to 19 years) who underwent congenital cardiac surgery between January and December 2012. The incidence of AKI within 7 days postoperatively was determined using the Kidney Disease: Improving Global Outcomes (KDIGO) criteria. Ninety-two patients (41.8%) developed AKI and 18 (8.2%) required renal replacement therapy within the first postoperative week. Among patients who developed AKI, 57 patients (25.9%) were KDIGO stage 1, 27 patients (12.3%) were KDIGO stage 2, and eight patients (3.6%) were KDIGO stage 3. RACHS-1 (Risk-Adjusted classification for Congenital Heart Surgery) category, perioperative transfusion and fluid administration as well as fluid overload were compared between patients with and without AKI. Multivariable logistic regression analyses determined the risk factors for AKI. AKI was associated with longer hospital stay or ICU stay, and frequent sternal wound infections. Younger age (<12 months) [odds ratio (OR), 4.01; 95% confidence interval (CI), 1.77–9.06], longer cardiopulmonary bypass (CPB) time (OR, 2.45; 95% CI, 1.24–4.84), and low preoperative hemoglobin (OR, 2.40; 95% CI, 1.07–5.40) were independent risk factors for AKI. Fluid overload was not a significant predictor for AKI. When a variable of hemoglobin concentration increase (>3 g/dl) from preoperative level on POD1 was entered into the multivariable analysis, it was independently associated with postoperative AKI (OR, 6.51; 95% CI, 2.23–19.03 compared with no increase). This association was significant after adjustment with patient demographics, medication history and RACHS-1 category (hemoglobin increase >3g/dl vs. no increase: adjusted OR, 6.94; 95% CI, 2.33–20.69), regardless of different age groups and cyanotic or non-cyanotic heart disease. Prospective trials are required to evaluate whether correction of preoperative anemia and prevention of hemoconcentration may ameliorate postoperative AKI in patients who underwent congenital cardiac surgery.

Outcome of aortic arch reconstruction in infants with coarctation: Importance of operative approach

OBJECTIVES

Coarctation with hypoplastic aortic arch can be treated with resection and extended end-to-end anastomosis (REEEA) as well as end-to-side anastomosis (ESA). The aim of the study was to review our experience with these techniques in newborns and infants and to assess mid-term outcome with regards to morbidity, mortality, and reintervention rate in relation to operative access and technique.

PATIENTS AND METHODS

Retrospective review of hospital charts and surgical reports from 183 consecutive newborns and infants with coarctation and hypoplastic aortic arch with or without ventricular septal defect between 1996 and 2013. Median age at surgery was 15 days (0-345). Lateral thoracotomy was used as operative access in 111 patients; 72 patients had a median sternotomy, 71 of them with cardiopulmonary bypass (ESA n = 30, REEEA n = 41). Fifty-two patients (28.4%) had an additional ventricular septal defect closure. Follow-up data were available for 75.96% with a median follow-up of 6.3 years (0.2-18.16 years).

RESULTS

Thirty-day mortality was 0.54% with no late mortality occurring during follow-up. There was 1 severe complication: paraplegia and cerebral hypoxemia after REEEA. Freedom from mortality and reintervention at 10 years was 99.27% and 90.12%, respectively. Lateral thoracotomy as operative access was a risk factor for recurrent obstruction (P = .03).

CONCLUSIONS

REEEA and ESA were safe and effective treatments in newborns and infants. In borderline cases, aortic arch reconstruction should be performed through a median sternotomy on bypass.

Acute Kidney Injury and Fluid Overload in Neonates Following Surgery for Congenital Heart Disease

BACKGROUND

Acute kidney injury (AKI) and fluid overload have been shown to increase morbidity and mortality. The reported incidence of AKI in pediatric patients following surgery for congenital heart disease is between 15% and 59%. Limited data exist looking at risk factors and outcomes of AKI or fluid overload in neonates undergoing surgery for congenital heart disease.

METHODS

Neonates aged 6 to 29 days who underwent surgery for congenital heart disease and who were without preoperative kidney disease were included in the study. The AKI was determined utilizing the Acute Kidney Injury Network criteria.

RESULTS

Ninety-five neonates were included in the study. The incidence of neonatal AKI was 45% (n = 43), of which 86% had stage 1 AKI. Risk factors for AKI included cardiopulmonary bypass time, selective cerebral perfusion, preoperative aminoglycoside use, small kidneys by renal ultrasound, and risk adjustment for congenital heart surgery category. There were eight mortalities (five from stage 1 AKI group, three from stage 2, and zero from stage 3). Fluid overload and AKI both increased hospital length of stay and postoperative ventilator days.

CONCLUSION

To avoid increased risk of morbidity and possibly mortality, every attempt should be made to identify and intervene on those risk factors, which may be modifiable or identifiable preoperatively, such as small kidneys by renal ultrasound.