Nitric Oxide in Selective Cerebral Perfusion Could Enhance Neuroprotection During Aortic Arch Surgery

BackgroundHypothermic circulatory arrest (HCA) in aortic arch surgery has a significant risk of neurological injury despite the newest protective techniques and strategies. Nitric oxide (NO) could exert a protective role, reduce infarct area and increase cerebral perfusion. This study aims to investigate the possible neuroprotective effects of NO administered in the oxygenator of selective antegrade cerebral perfusion (SCP) during HCA.MethodsThirty male SD adult rats (450–550 g) underwent cardiopulmonary bypass (CPB), cooling to 22°C body core temperature followed by 30 min of HCA. Rats were randomized to receive SCP or SCP added with NO (20 ppm) administered through the oxygenator (SCP-NO). All animals underwent CPB-assisted rewarming to a target temperature of 35°C in 60 min. At the end of the experiment, rats were sacrificed, and brain collected. Immunofluorescence analysis was performed in blind conditions.ResultsNeuroinflammation assessed by allograft inflammatory factor 1 or ionized calcium-binding adapter molecule 1 expression, a microglia activation marker was lower in SCP-NO compared to SCP (4.11 ± 0.59 vs. 6.02 ± 0.18%; p < 0.05). Oxidative stress measured by 8oxodG, was reduced in SCP-NO (0.37 ± 0.01 vs. 1.03 ± 0.16%; p < 0.05). Brain hypoxic area extent, analyzed by thiols oxidation was attenuated in SCP-NO (1.85 ± 0.10 vs. 2.74 ± 0.19%; p < 0.05). Furthermore, the apoptotic marker caspases 3 was significantly reduced in SCP-NO (10.64 ± 0.37 vs. 12.61 ± 0.88%; p < 0.05).ConclusionsNitric oxide administration in the oxygenator during SCP and HCA improves neuroprotection by decreasing neuroinflammation, optimizing oxygen delivery by reducing oxidative stress and hypoxic areas, finally decreasing apoptosis.

Preliminary results of single centre experience with the “release and perfuse technique” during aortic arch surgery.

Background and aim of the study To evaluate whether the release and perfuse technique implies a circulatory arrest time comparable with or shorter than those of standard Frozen Elephant Trunk technique in aortic arch surgery. Methods We retrospectively reviewed the records of patients who had undergone aortic arch repair with Release and Perfuse Technique (RPT) or standard Frozen Elephant Trunk (FET) at our Institution between January 2018 and May 2021. Primary endpoints were the comparison of circulatory arrest time, perioperative variables, and complications between two groups. A propensity score weighting approach was used for data analysis. Results A total of 41 patients underwent aortic arch surgery were analyzed:15 (37%) and 26 (63 %) in RPT and FET group, respectively. The use of RPT showed a significant shorter circulatory arrest times than FET: 9 min vs 58 min (P < 0.001), respectively. The median lactates peak in the first 24h post intervention was 2.6 for RPT group and 5.4 mmol/L for FET group, (P <0.0001). When compared with the FET, RPT is associated with significant reduction in the use of packed red blood cells (P <0.0001), fresh frozen plasma (P <0.0001), platelet concentrate (P <0.0001), and fibrinogen (P <0.004). The median ICU stay was 3 and 9 days (P = 0.011), whereas the median hospital stay was 12 and 18.5 days (P=0.004) in the RPT and FET groups, respectively. Thirty-day mortality and postoperative outcomes were comparable between the two groups. Conclusions Considering the anatomical limitations related to the use of this technique, the RPT appears to be safe, feasible, and effective in reducing the circulatory arrest time during aortic arch surgery. Nevertheless, further studies are required to demonstrate its safety and efficacy.

Using self -suture branching artificial vesssels in aortic arch surgery at Hanoi Heart Hospital

Background: For aortic arch surgery, the improvement of anastomosis technique, and the improvement of using self-suture branching artificial vessels have shortened the time and reduced the cost of surgery. The study aimed to evaluate the improved results of using self-suture branched artificial vessels in aortic arch surgery. Methods: A retrospective descriptive study of the use of self-suture branching artificial vessels in aortic arch surgery at Hanoi Heart Hospital from October 2018 to May 2021. Results: There were 33 cases of aortic arch replacement using self-suture branching artificial vessels. The rate of postoperative bleeding was 6.06%. The rate of artificial vessel infection is 0%. Conclusion: Using self-suture branching artificial vessels in aortic arch surgery is a safe and effective technique.

Risks and Association of Impaired Cerebral Autoregulation With Outcomes in Aortic Arch Surgery: A Single-center, Retrospective Cohort Study

BackgroundImpairment of cerebral autoregulation (CA) has been observed in patients undergoing cardiopulmonary bypass (CPB), but little is known about its risks and associations with outcomes. The objective of this study was to analyze the risks of impaired CA, based on cerebral oximetry index (COx), in patients undergoing total aortic arch replacement with CPB and moderate hypothermic circulatory arrest (MHCA). We also evaluated the association between impaired CA and patient outcomes.MethodsOne hundred fifteen four adult patients who underwent total aortic arch replacement with stented elephant trunk implantation under CPB and MHCA at our hospital were retrospectively analyzed. Patients were defined as having new-onset impaired CA if post-CPB COx > 0.3, calculated based on a moving linear correlation coefficient between regional cerebral oxygen saturation (rScO2) and mean blood pressure (MAP). Pre- and intraoperative factors were tested for independent association with impaired CA. Postoperative outcomes were compared between patients with normal and impaired CA.ResultsIn our 154 patients, 46(29.9%) developed new-onset impaired CA after CPB with MHCA. Multivariate analysis revealed a prolonged low rScO2 (rScO2 <55%) independently associated with onset of impaired CA, and receiver operating charactoristic curve showed a cutoff value at 40 min (sensitivity, 89.5%; specificity, 68.0%). Compared with normal CA patients, those with impaired CA showed a significantly higher rates of in-hospital mortality and postoperative complications.ConclusionProlonged low rScO2 (rScO2 <55%) during aortic arch surgery was closely related to onset of impaired CA. Impaired CA remained associated with the increased rates of postoperative complications and in-hospital mortality.Trial registration: ChiCTR1800014545 with registered date 20/01/2018.

Reoperative Aortic Arch Surgery under Mild Systemic Hypothermia: Two-Center Experience

Background The aim of the study was to assess the indications, surgical strategies, and outcomes after reoperative aortic arch surgery performed generally under mild hypothermia. Methods Ninety consecutive patients (60 males, mean age, 55 ± 16 years) underwent open reoperative aortic arch surgery after previous cardiac aortic surgery. The indications included chronic-progressive arch aneurysm (55.5%), chronic aortic dissection (17.8%), contained arch rupture (16.7%), and graft infection (10%). The reoperation was performed through a repeat sternotomy (96%) or clamshell thoracotomy (4%) using antegrade cerebral perfusion under mild systemic hypothermia (28.9 ± 2.5°C) in all except three patients. Results The surgery comprised hemiarch or total arch replacement in 41 (46%) and 49 (54%) patients, respectively. The distal extension included classic or frozen elephant trunk technique, each in 12 patients, and total descending aorta replacement in 4 patients. Operative mortality was 6 (6.7%) among all patients, with age identified as the only independent predictor of operative mortality (p = 0.05). Permanent and transient neurologic deficits occurred in 1% and 9% of the patients, respectively. Estimated survival at 8 years was 59 ± 8% with advanced heart failure predictive for late mortality (p = 0.014). Freedom from second reoperation or intervention on the aorta was 78 ± 6% at 8 years, with most of these events occurring downstream in patients with chronic degenerative aneurysms. Conclusion Aortic arch reoperations performed using antegrade cerebral perfusion under mild systemic hypothermia offer favorable operative outcomes with an exceptionally low rate of neurologic morbidity without any difference between hemiarch and complex arch procedures.