Regional cerebral perfusion for surgical correction of neonatal aortic arch obstruction

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.

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.

Aortic arch enlargement and coarctation repair through a left thoracotomy: significance of ductal perfusion

OBJECTIVE

To analyse the technique of neonatal aortic arch enlargement without cardiopulmonary bypass through a left posterior thoracotomy, as an adjunct to extended resection for Coarctation and severe arch hypoplasia.

METHODS

Ten neonates with coarctation, severe arch hypoplasia and a persistent ductus arteriosus (PDA) were subjected to arch repair through a left posterior thoracotomy. Nine of these patients had associated significant intracardiac anomalies; three of them received pulmonary artery (PA) banding. After exclusion from circulation, the roof of the intervening arch between left carotid and left subclavian was enlarged using a patch. After adequate reperfusion, a classic resection and extended end-to-end anastomosis was performed. Median age and weight were 5.5 (1-10) days and 3.3 (2.2-4.1) kg respectively. The median preoperative arch diameter was 1.07 (0.75-1.32) mm/kg body weight.

RESULTS

All patients could be successfully operated with this approach. The non-ischaemic and ischaemic aortic clamp times were 40 (15-68) and 23 (18-32) min, respectively. The median postoperative arch diameter achieved was 1.43 (1.06-1.46) mm/kg body weight. None of the patients had significant gradient early postoperatively. Two patients with recurrent stenosis were successfully treated with balloon dilatation (1) or surgery with cardiopulmonary bypass (CPB) (1). One patient has a corrected gradient of 16 mmHg in the proximal arch which is being observed. The remaining patients are free from stenosis at a median follow-up of 30.1 (13.2-57.8) months.

CONCLUSIONS

Use of PDA for lower body perfusion allows complex reconstruction of the arch without incurring lower body ischaemia. The extended resection could then be performed without excessive stretch. This modification saves these patients from undergoing a complex arch reconstruction with CPB in the early neonatal period.

Open aortic arch surgery: how to reduce air embolism risk during antegrade cerebral perfusion

Antegrade cerebral perfusion (ACP) is used widely, with the aim of obtaining cerebral protection during open aortic arch surgery. ACP is considered by many to be the reason for improvements in the clinical outcome of this type of surgery. However, perioperative cerebral complications may still occur. Cerebral complications during ACP are considered to be due mainly to embolic events rather than hypoperfusion. We believe that many of the embolic events during ACP may be due to air embolism rather than to vessel manipulation only. To reduce the risk of air embolism during ACP, we propose an easy technique, with the suggested steps to be followed in an exact sequence.