Regional High-Flow Cerebral Perfusion Improves Both Cerebral and Somatic Tissue Oxygenation in Aortic Arch Repair

Whole-Body Perfusion in Neonates and Infants Undergoing Aortic Arch Surgery-Working Towards the New Standard

Background: Neonatal aortic arch surgery remains one of the most challenging procedures in congenital cardiac surgery. In recent years, there has been a trend away from selective cerebral perfusion (SCP) and arrest of body circulation towards whole-body perfusion (WBP), a combination of SCP and lower-body perfusion (LBP), to facilitate arch surgery and preserve organ function. Methods: Retrospective, single-centre analysis was conducted of patients under one year of age undergoing aortic arch surgery from January 2014 until December 2022. SCP was used from January 2014-December 2017; WBP was implemented from January 2017-December 2022. Patients were separated according to the type of perfusion used during surgery, SCP or WBP. The cohort consisted of a total of 95 patients, 34 in the SCP group and 61 in the WBP group. Results: Patients in the WBP group showed significantly lower rates of intraoperative transfusions, namely red blood cells, fresh-frozen plasma and thrombocytes (p-value < 0.01, <0.01, and <0.01, respectively). The WBP group showed significantly lower creatinine and higher urine output values 24 and 72 h after surgery (p-value = 0.02, <0.01, respectively). The WBP group showed a significant lower incidence of major neurological complications (p-value 0.01). Binary logistic regression analyses showed favourable outcomes for the WBP group regarding 30-day mortality (OR = 0.03, CI = 0.003-0.391, p-value = <0.01), multiorgan failure (OR = 0.002, CI = 0-0.275, p-value = 0.01), neurological complications (OR = 0.994, CI = 0.998-1, p-value = 0.06) and postoperative renal replacement therapy (RRT) (OR = 0.989, CI = 0.983-0.995, p-value = <0.01). Conclusions: Patients with WBP received fewer intraoperative transfusions, showed improved postoperative renal function and suffered significantly fewer neurological complications.

Coarctation of the aorta with total anomalous pulmonary venous connection: a case report

Total anomalous pulmonary venous connection (TAPVC) and coarctation of the aorta (CoA) rarely occur together. In affected patients, blood is supplied to the lower body by saturated ductal flow. Preoperative echocardiography may not show an acceleration of flow at the isthmus (coarctation), and the oxygen saturation (SpO₂) at the feet may be satisfactory. Consequently, the severity of CoA is often underestimated before performing surgery. A 6-day-old boy weighing 2.6 kg with a diagnosis of supracardiac TAPVC was referred for surgical correction of his anomaly. The atrial septal defect (ASD) was 6.7 mm in diameter. There was a large patent ductus arteriosus (PDA) without flow acceleration at the preductal entry into the descending aorta. Only the TAPVC repair was planned, but immediately following ligation of the large PDA, the blood pressure in the lower extremity dropped to around 30 mmHg. The ligation was removed. The reason for the blood pressure discrepancy between the upper and the lower body was not clear as there was no arterial line in the upper extremity and a 6.7-mm-diameter ASD can support sufficient blood flow to the lower body without the PDA. A suspected CoA was found and repaired, followed by the TAPVC repair. Caution is necessary when repairing a TAPVC and coexisting large PDA as the severity of the CoA can easily be underestimated due to nonsignificant flow acceleration.

Avoiding use of total circulatory arrest in the practice of congenital heart surgery

Deep hypothermic circulatory arrest (DHCA) technique has been an important armamentarium in the correction of congenital heart diseases. There have been many controversies and concerns associated with DHCA, particularly neurological damage. Selective ante grade cerebral perfusion (SACP) was introduced as an adjunct to DHCA with the objective of limiting the neurologic injury during aortic arch repairs. Over the past two decades, various aspects of cardiopulmonary bypass and DHCA have been studied and modified such as optimisation of flows, anti-inflammatory interventions, haematocrit, and temperature to improve neurologic outcomes. With the changes in practice of DHCA, outcomes have significantly improved but SACP intuitively appears attractive to offer better neuroprotection. The strategy of conduct of SACP is evolving and needs to be standardised for comparing outcomes. In this review we have discussed the various physiological and technical factors involved in conduct of SACP in paediatric cardiac surgery and outcomes with SACP.

Blood Glucose and Lactate Levels and Cerebral Oxygenation in Preterm and Term Neonates-A Systematic Qualitative Review of the Literature

Background: Cerebral oxygenation monitored non-invasively by near-infrared spectroscopy (NIRS) is of increasing interest in neonatal care. Cerebral oxygenation is determined by cerebral oxygen delivery and cerebral oxygen consumption. Oxygen delivery as well as oxygen consumption might be influenced by metabolic parameters like blood glucose and lactate. Objective: The aim of the present systematic qualitative review is therefore to identify and summarize all studies, which describe cerebral oxygenation measured with NIRS and blood glucose and/or blood lactate levels in neonates. Data sources: A systematic search of Ovid Embase and PubMed was performed. Search terms included near-infrared spectroscopy, fractional tissue oxygen extraction, cerebral tissue oxygen saturation, regional cerebral tissue oxygen saturation, oxygenation, term, and preterm neonates, cesarean delivery, transition, after-birth, newborn, vaginal delivery, cesarean delivery, baby, neonatal transition, metabolism, lactate, glucose, and blood glucose level. Study selection/data synthesis: Studies analyzing cerebral oxygenation and blood glucose and/or blood lactate levels in neonates were included. Animal studies, duplicates, or studies in non-English language were excluded. Results: Twenty-five studies were identified that describe blood glucose and/or blood lactate levels as primary or secondary outcome parameters with additional measured cerebral oxygenation by NIRS in neonates. Twelve studies were included with blood glucose measurements: four described an association between blood glucose levels and cerebral oxygenation, two show no association, and six do not report on possible associations. Eighteen studies were included with lactate measurements: one describe an association between lactate levels and cerebral oxygenation, while three show no association and 14 do not report on possible associations. Discussion: The influence of blood glucose and blood lactate levels on the cerebral oxygenation in neonates is still controversial. However, there seems to be an association between cerebral oxygenation and the metabolic parameter blood glucose and lactate, which need further investigation.

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.

Markers of peripheral perfusion during high-flow regional cerebral perfusion for aortic arch repair

OBJECTIVES

High-flow regional cerebral perfusion (HFRCP) provides cerebral and somatic oxygen delivery through collateral vessels during aortic arch repair in small children; however, optimal flow conditions during HFRCP have not been established. We sought to identify markers of peripheral perfusion during HFRCP.

METHODS

Between 2009 and 2016, in total 20 consecutive pediatric patients undergoing aortic arch repair with HFRCP were enrolled in this prospective, observational study. Median age was 20 days (range, 6-116 days); median body weight was 2.77 kg (range, 1.8-4.98 kg). Oxygen delivery ratio (Do₂R) was calculated as the oxygen delivery during HFRCP divided by the oxygen delivery before HFRCP. Regional oxygen saturations on the forehead and on the thigh (rSo₂T) were monitored during HFRCP, and postoperative creatinine kinase and lactate concentrations were measured as postoperative outcomes. Multivariate analyses were performed to clarify the effectiveness of Do₂R and rSo₂T as markers of peripheral perfusion during HFRCP.

RESULTS

No deaths or neurologic impairments occurred. Multivariate analysis showed that the lowest rSo₂T (P = .005) and cardiopulmonary bypass time (P = .012) predicted postoperative creatinine kinase concentration. Do₂R was the only factor to predict postoperative lactate concentration (P < .001). Receiver operating characteristic analysis showed that Do₂R less than 0.66 predicted risk of high postoperative lactate concentration (>5.0 mmol/L), with area under the curve of 0.95.

CONCLUSIONS

For aortic arch repair in small children, rSo₂T and Do₂R during HFRCP are useful markers for predicting peripheral perfusion. Maintaining higher Do₂R during HFRCP minimizes postoperative increases in lactate and creatinine kinase concentrations.

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.

Antegrade cerebral perfusion at 25 °C for arch reconstruction in newborns and children preserves perioperative cerebral oxygenation and serum creatinine

BACKGROUND

Antegrade cerebral perfusion (ACP) typically is used with deep hypothermia for cerebral protection during aortic arch reconstructions. The impact of ACP on cerebral oxygenation and serum creatinine at a more tepid 25 °C was studied in newborns and children.

METHODS

Between 2010 and 2014, 61 newborns and children (<5 years old) underwent aortic arch reconstruction using moderate hypothermia (25.0±0.9 °C) with ACP and a pH-stat blood gas management strategy. These included 44% Norwood-type operations, 30% isolated arch reconstructions, and 26% arch reconstructions with other major procedures. Median patient age at surgery was 9 days (range, 3 days-4.7 years). Cerebral oxygenation (NIRS) was monitored continuously perioperatively for 120 hours. Serum creatinine was monitored daily.

RESULTS

Median cardiopulmonary bypass (CPB) and cross clamp times were 181 minutes (range, 82-652 minutes) and 72 minutes (range, 10-364 minutes), respectively. ACP was performed at a mean flow rate of 46±6 mL/min/kg for a median of 48 minutes (range, 10-123 minutes). Cerebral and somatic NIRS were preserved intraoperatively and remained at baseline postoperatively during the first 120 hours. Peak postoperative serum creatinine levels averaged 0.7±0.3 mg/dL for all patients. There were 4 (6.6%) discharge mortalities. Six patients (9.8%) required ECMO support. Median postoperative length of hospital and intensive care unit (ICU) stay were 16 days(range, 4-104 days) and 9 days (range, 1-104 days), respectively. Two patients (3.3%) received short-term peritoneal dialysis for fluid removal, and none required hemodialysis. Three patients (4.9%) had an isolated seizure which resolved with medical therapy, and none had a neurologic deficit or stroke.

CONCLUSIONS

ACP at 25 °C preserved perioperative cerebral oxygenation and serum creatinine for newborns and children undergoing arch reconstruction. Early outcomes are encouraging, and additional study is warranted to assess the impact on late outcomes.

Five-year experience with the peri-operative goal directed management for surgical repair of traumatic aortic injury in the eastern province, Saudi Arabia

Context:

Traumatic aortic injury (TAI) accounts for 1/3 of all trauma victims.

Aim:

We aimed to investigate the efficacy of the adopted standardized immediate pre-operative and intra-operative hemodynamic goal directed control, anesthetic technique and organs protection on the morbidity and mortality in patients presented with TAI.

Settings and Design:

An observational retrospective study at a single university teaching hospital.

Materials and Methods:

Following ethical approval, we recruited the data of 44 patients admitted to the King Fahd Hospital of the University, Al Khobar, Saudi Arabia, with formal confirmation of diagnosis of blunt TAI during a 5-year period from February 2008 to April 2013 from the hospital medical records.

Statistical Analysis:

descriptive analysis.

Results:

A total of 44 victims (41 men, median (range) age 29 (22-34) years) with TAI who underwent surgical repair were recruited. Median (range) post-operative chest tube output was 700 (200-1100) ml necessitated transfusion in 5 (11.4%) of cases. Post-operative complications included transient renal failure (13.6%), pneumonia (6.8%), acute lung injury/distress syndrome (20.5%), sepsis (4.5%), wound infection (47.7%) and air leak (6.8%). No patient developed end stage renal failure or spinal cord injury. Median intensive care unit stay was 6 (4-30) days and in-hospital mortality was 9.1%.

Conclusion:

We found that the implementation of a standardized early goal directed hemodynamic control for the peri-operative management of patients with TAI reduces the post-operative morbidity and mortality after surgical repair.

Innominate artery cannulation and antegrade cerebral perfusion for aortic arch reconstruction in infants and children

PURPOSE

Innominate artery cannulation has been widely adopted as a means to perform aortic arch reconstruction with continuous cerebral perfusion in the newborn. Although this technique has been subsequently utilized in infants and children, there is currently no data regarding the safety or efficacy in these older children. The purpose of this study was to review our experience with innominate artery cannulation for aortic arch reconstruction in patients beyond the neonatal period.

METHODS

This was a retrospective review of 42 infants and children who underwent aortic arch reconstruction using the technique of innominate artery cannulation with continuous cerebral perfusion. Of these procedures, 29 (69%) were primary arch reconstructions, while 13 (31%) were aortic arch reoperations. The median age at surgery was 8 months, and 22 patients underwent concomitant intracardiac repairs.

RESULTS

There was no operative mortality in this cohort of 42 patients undergoing aortic arch reconstruction. There was also no overt evidence of neurologic injury. Specifically, none of the patients demonstrated a neurologic deficit, clinical seizure, or unexpected delay in regaining a normal state of consciousness. The median duration of antegrade cerebral perfusion was 34 minutes. The median duration of hospital stay was 11 days. No patient required reoperation on the aortic arch with a median of 45-month follow-up.

CONCLUSIONS

Innominate artery cannulation is a safe and effective technique for aortic arch reconstruction in nonneonates. We conclude that antegrade cerebral perfusion is a useful technique for aortic arch reconstruction in this patient population.

Neonatal repair of right interrupted aortic arch with cerebro-myocardial perfusion technique

Right interrupted aortic arch and descending aorta is exceedingly rare and most likely cause respiratory presentation, since patent ductus arteriosus (PDA) courses over the right mainstem bronchus. We report a case of successful neonatal biventricular repair of a right interrupted aortic arch (type B), with an aberrant right subclavian artery ventricular septal defect (VSD) in a 2.7 kg term neonate with DiGeorge syndrome. Patient presented in severe respiratory distress and acidosis at one day old. Two-dimensional (2D) echocardiography revealed aortic arch interruption beyond the common carotid arteries with large perimembranous outlet VSD. Aortic annulus diameter was 4.8 mm and there was no left ventricle (LV) outflow tract obstruction. Three-dimensional (3D) CT-scan confirmed these findings and identified a right-sided ductal arch that continued over the right mainstem bronchus into a right-sided descending aorta and aberrant right subclavian artery. Brachiocephalic perfusion and ductal perfusion was employed for cooling during cardiopulmonary bypass. Under deep hypothermia (27 °C rectal temperature), selective cerebro-myocardial perfusion was used for successful aortic arch repair without sacrificing the aberrant right subclavian artery. A direct tension-free anastomosis was attained. Her postoperative course was uneventful and her respiratory symptoms disappeared postoperatively. Early surgical correction is mandatory for these patients with unique anatomy and presentation.

The effectiveness of high-flow regional cerebral perfusion in Norwood stage I palliation

OBJECTIVE

Regional cerebral perfusion (RCP) has been shown to provide cerebral circulatory support during Norwood procedure. In our institution, high-flow RCP (HFRCP) from the right innominate artery has been induced to keep sufficient cerebral and somatic oxygen delivery via collateral vessels. We studied the effectiveness of HFRCP to regional cerebral and somatic tissue oxygenation in Norwood stage I palliation.

METHODS

Seventeen patients, who underwent the Norwood procedure, were separated into two groups: group C (n=6) using low-flow RCP and group H (n=11) using HFRCP (mean flow: 54 vs 92mlkg(-1)min(-1), P<0.0001). The mean duration of RCP was 64±10min (range, 49-86min) under the moderate hypothermia. Chlorpromazine (3.0mgkg(-1)) was given to group H patients before and during RCP to increase RCP flow. The mean radial arterial pressure was kept <50mmHg during RCP. To clarify the effectiveness of HFRCP for cerebral and somatic tissue oxygenation, cerebral regional oxygen saturation (rSO(2)) and systemic venous oxygenation (SvO(2)) during RCP were compared between the two groups. Changes in the lactate level before and after RCP, and changes in the blood urea nitrogen (BUN), creatinine, lactate dehydrogenase (LDH), and creatinine kinase (CK) levels before and after surgery, were also compared between the groups.

RESULTS

Mean rSO(2) was 82.9±9.0% in group H and 65.9±10.7% in group C (P<0.05). Mean SvO(2) during RCP was 98.2±4.3% in group H and 85.4±9.7% in group C (P<0.01). During RCP, lactate concentration significantly increased in group C compared with that in group H (P<0.001). After surgery, the LDH and CK levels significantly increased in group C compared with that in group H (P<0.05).

CONCLUSIONS

Our study revealed that HFRCP preserved sufficient cerebral and somatic tissue oxygenation during the Norwood procedure. The reduction of vascular resistance of collateral vessels increased both cerebral and somatic blood flow, resulting in improved tissue oxygen delivery.