Aortic arch surgery presents significant challenges in maintaining adequate cerebral perfusion, particularly when using selective antegrade cerebral perfusion (SACP) under moderate hypothermia. Effective intraoperative monitoring is crucial to prevent neurological complications. This study explores the integration of continuous venous drainage flow monitoring and oxygen extraction (ERiO2) via near-infrared spectroscopy (NIRS) to enhance cerebral perfusion management.
The study retrospectively analyzed data from 10 patients who underwent aortic arch surgery with the Kazui technique. The cohort included 4 patients with type I A dissections and 6 with aortic arch aneurysms. During surgery, bilateral NIRS (Masimo system) was used to assess regional oxygen saturation (rSO2), while venous drainage flow and ERiO2 were continuously measured via the Landing system. Other intraoperative parameters included cardiopulmonary bypass (CPB) duration, perfusion flow rates, and temperature modulation phases.
Key findings from the study highlight the importance of continuous cerebral monitoring:
- CPB time averaged 182 ± 15 minutes, with a cross-clamp time of 98 ± 12 minutes.
- Patients underwent controlled cooling to 20°C in 29 ± 3 minutes, followed by 10 minutes of systemic reperfusion and a structured rewarming phase.
- Perfusion flow rates averaged 620 ± 30 mL/min, while venous return flow was 570 ± 25 mL/min.
- NIRS measurements remained stable, with an average rSO2 of 65 ± 5%, while ERiO2 averaged 28 ± 4%.
- A strong correlation (r = 0.91, p < 0.01) was observed between rSO2 and ERiO2, emphasizing the role of venous return in cerebral oxygenation.
The study demonstrates that continuous monitoring of cerebral perfusion parameters can provide real-time insights into oxygen delivery and metabolic balance. The correlation between rSO2 and ERiO2 supports the use of these metrics in guiding perfusion management, particularly in high-risk procedures requiring prolonged circulatory arrest.
Postoperatively, all patients had favorable neurological outcomes, with no reported strokes or major complications. The average mechanical ventilation duration was 8.5 ± 2.3 hours, ICU stays lasted 48 ± 12 hours, and hospital stays averaged 10 ± 3 days. No mortality was reported within 30 days.
Despite promising results, the study acknowledges limitations:
- Small sample size (10 patients) restricts the generalizability of findings.
- Single-center study design may introduce institutional bias.
- Lack of long-term follow-up prevents assessment of lasting neurological outcomes.
- No control group to compare the monitoring approach with standard perfusion strategies.
Future research should focus on multicenter trials with larger cohorts, long-term neurological assessments, and advanced monitoring algorithms using machine learning. By refining cerebral perfusion strategies, these advancements could minimize complications and improve patient outcomes in aortic arch surgery.
This study underscores the potential of integrating NIRS, ERiO2, and venous drainage flow monitoring to optimize cerebral perfusion. These findings suggest that a multimodal approach could enhance intraoperative decision-making, leading to better patient safety and surgical precision.
Study Ranking: 3.5 (Moderate to High-Quality Study) This study provides valuable insights into cerebral perfusion monitoring using advanced techniques, but its small sample size and retrospective design limit its generalizability. While findings are promising, further large-scale, prospective trials are needed to validate results and establish standardized protocols.
