Selective cerebral perfusion for cerebral protection: what we do know

Cerebral hypoperfusion resulting from improper cannulation positioning during aortic dissection surgery: a case report

BACKGROUND

Selective antegrade cerebral perfusion (sACP) is a crucial cerebral protection technique employed during aortic dissection surgeries involving cardiopulmonary bypass. However, postoperative neurological complications, particularly those related to cannulation issues and perfusion problems, remain a significant concern.

CASE PRESENTATION

This case report details an unusual instance where a 38-year-old male patient with Marfan syndrome experienced cerebral hypoperfusion during emergency surgery for Stanford Type A aortic dissection. Despite following standard protocols, a significant drop in regional cerebral oxygen saturation (rSO2) and abnormal blood pressure fluctuations were observed shortly after initiating sACP via the innominate artery. After initial attempts to optimize perfusion flow proved ineffective, the cannulation position was adjusted, leading to improvements. Nevertheless, the patient subsequently exhibited signs of cerebral hypoperfusion and was found to have suffered a new cerebral infarction.

CONCLUSIONS

This case report underscores the importance of precise cannula placement during sACP procedures and the dire consequences that can arise from improper positioning. It emphasizes the need for continuous monitoring and prompt intervention in cases of abnormal cerebral oxygenation and blood pressure, as well as the value of considering cannulation-related issues as potential causes of postoperative neurological complications.

Near-Infrared Spectroscopy Assessment of Tissue Oxygenation During Selective Cerebral Perfusion for Neonatal Aortic Arch Reconstruction

Objective: Optimal selective cerebral perfusion (SCP) management for neonatal aortic arch surgery has not been extensively studied. We induced mild hypothermia during SCP and used the tissue oxygenation monitor to ensure adequate perfusion during the cardiopulmonary bypass (CPB). Methods: Eight cases were recruited from September 2018 to April 2020. SCP was maintained at 30°C, and CPB was adjusted to achieve a mean right radial artery pressure of 30 mmHg. The near-infrared tissue saturation (NIRS) monitor was applied to assess the right and left brain, flank, and lower extremity during the surgery. Results: During surgery, the mean age was 4.75 days, the mean body weight was 2.92 kg, the CPB duration was 86.5 ±18.7 min, the aortic cross-clamp time was 46.1 ± 12.7 min, and the SCP duration was 14.6±3.4 min. The brain NIRS before, during, and after SCP was 64.2, 67.2, and 71.5 on the left side and 67.9, 66.2, and 70.1 on the right side (p = NS), respectively. However, renal and lower extremity tissue oxygenation, respectively decreased from 61.6 and 62.4 before SCP to 37.7 and 39.9 after SCP (p < 0.05) and then increased to 70.1 and 90.4 after full body flow resumed. No stroke was reported postoperatively. Conclusion: SCP under mild hypothermia can aid in efficient maintenance of brain perfusion during neonatal arch reconstruction. The clinical outcome of this strategy was favorable for up to 20 min, but the safety duration of lower body ischemia warrants further analysis.

Aortic arch aneurysms and dissection-open repair is the gold standard

The aortic arch repair is one of the most complex surgeries and carries a high risk of complications as well as mortality. Since 1975, when the arch repair was first done by Randall B. Griepp using hypothermic circulatory arrest, many new technologies were introduced. But even with the use of antegrade and retrograde perfusion techniques and improvement of surgical techniques and grafts, the rate of mortality, cerebral, spinal, and visceral damage was much higher as compared to any other cardiac surgeries. With further developments aimed at less invasive approaches, thoracic endovascular aortic repair (TEVAR) along with de-branching of supra-aortic vessels or the frozen elephant trunk was introduced. Here, in this article, we review the myriad of approaches to the aortic arch and have come to a conclusion that while traditional open surgery is considered as the gold standard for treatment of extensive aortic arch pathologies, one school of thought suggests hybrid techniques such as the frozen elephant trunk and aortic arch vessel de-branching as more appropriate procedures for high-risk patients, where co-morbidities may contraindicate cardiopulmonary bypass and longer operative times required for traditional repair. No randomized trials are present to compare between open and hybrid or endovascular procedure in normal or high-risk patients. The meta-analysis of most of the studies defines open surgery as the gold standard for arch pathology because the hybrid procedures did not provide any proven survival benefits or decrease in stroke rate and spinal ischemia when compared to open surgery in early, mid, or long-term results.