Use of On-Site Digital Subtraction Angiography for Left Subclavian Artery Management During Hybrid Aortic Arch Repair in DeBakey I Dissection

Purpose: A hybrid aortic repair using the frozen elephant trunk (FET) technique with an open distal anastomosis in zone 2 and debranching of the left subclavian artery (LSA) has been demonstrated to be favorable and safe. Although a transposition of the LSA reduces the risk of cerebellar or medullar ischemia, this may be challenging in difficult LSA anatomies. Case Report: We present the case of a 61-year old patient with DeBakey I aortic dissection, treated with FET in moderate hypothermic circulatory arrest (26°C) and selective cerebral perfusion using a Thoraflex-Hybrid (Vascutek Terumo) prosthesis anchored in zone 2, with overstenting of the LSA orifice and no additional LSA debranching. Sufficient perfusion of the LSA was proved intraoperatively using LSA backflow analysis during selective cerebral perfusion in combination with on-site digital subtraction angiography (ARTIS Pheno syngo software). No neurologic dysfunction or ischemia occurred in the postoperative course. An angiographic computed tomography revealed physiologic LSA perfusion, with subsequent thrombotic occlusion of the false lumen in the proximal descending aorta after 7 days. Conclusion: Using an angiography-guided management in patients with complex DeBakey I dissection and difficult anatomy may simplify a proximalization of the distal anastomosis in zone 2 for FET, even without an additional LSA debranching.

The effect of selective cerebral perfusion on cerebral versus somatic tissue oxygenation during aortic coarctation repair in neonates and infants

Background Suboptimal tissue perfusion and oxygenation may be the root cause of certain perioperative complications in neonates and infants having complicated aortic coarctation repair. Practical, effective, and real-time monitoring of organ perfusion and/or tissue oxygenation may provide early warning of end-organ mal-perfusion. Methods Neonates/infants who were scheduled for aortic coarctation repair with cardiopulmonary bypass (CPB) and selective cerebral perfusion (SCP) from January 2015 to February 2017 in Children’s Hospital of Nanjing Medical University participated in this prospective observational study. Cerebral and somatic tissue oxygen saturation (SctO2 and SstO2) were monitored on the forehead and at the thoracolumbar paraspinal region, respectively. SctO2 and SstO2 were recorded at different time points (baseline, skin incision, CPB start, SCP start, SCP end, aortic opening, CPB end, and surgery end). SctO2 and SstO2 were correlated with mean arterial pressure (MAP) and partial pressure of arterial blood carbon dioxide (PaCO2). Results Data of 21 patients were analyzed (age=75±67 days, body weight=4.4±1.0 kg). SstO2 was significantly lower than SctO2 before aortic opening and significantly higher than SctO2 after aortic opening. SstO2 correlated with leg MAP when the measurements during SCP were (r=0.67, p<0.0001) and were not included (r=0.46, p<0.0001); in contrast, SctO2 correlated with arm MAP only when the measurements during SCP were excluded (r=0.14, p=0.08 vs. r=0.66, p<0.0001). SCP also confounded SctO2/SstO2’s correlation with PaCO2; when the measurements during SCP were excluded, SctO2 positively correlated with PaCO2 (r=0.65, p<0.0001), while SstO2 negatively correlated with PaCO2 (r=-0.53, p<0.0001). Conclusions SctO2 and SstO2 have distinct patterns of changes before and after aortic opening during neonate/infant aortic coarctation repair. SctO2/SstO2’s correlations with MAP and PaCO2 are confounded by SCP. The outcome impact of combined SctO2/SstO2 monitoring remains to be studied.

Fluttering cord-like thrombus in the aortic arch: a case report

BackgroundOptimal treatment for aortic thrombus remains to be determined, but surgical treatment is indicated when there is a risk for thromboembolism. Case PresentationA 47-year-old male presented with weakness in his left arm upon awakening. Contrast-enhanced computed tomography and transesophageal echocardiography revealed a mobile pedunculated object suggestive of a thrombus arising from the ascending aorta and extending to the left common carotid artery. It was removed under hypothermic circulatory arrest and direct cannulation of the left carotid artery to avoid carotid thromboembolism. Histopathological examination revealed that the object was a thrombus. The patient had an uneventful postoperative course and was discharged 9 days after surgery. ConclusionWhen a thrombus in the aortic arch extends to the neck arteries, direct cannulation of the neck arteries with selective cerebral perfusion via cervical incision is a useful technique.

Total arch replacement in octogenarians

OBJECTIVES We investigated the effect of a preoperative age ≥80 years on postoperative outcomes in patients who underwent isolated elective total arch replacement using mild hypothermic lower body circulatory arrest with bilateral antegrade selective cerebral perfusion. METHODS A total of 140 patients who had undergone isolated elective total arch replacement between January 2007 and December 2020 were enrolled in the present study. We compared postoperative outcomes between 30 octogenarian patients (≥80 years old; Octogenarian group) and 110 non-octogenarian patients (≤79 years old; Non-Octogenarian group). RESULTS Overall 30-day mortality and hospital mortality were 0% in both groups, and there was no significant difference in overall survival between the 2 groups (log-rank test, P = 0.108). Univariable Cox proportional hazard analysis showed that age as continuous variable was only the predictor of mid-term all-cause death (hazard ratio 1.08, 95% confidence interval 1.01–1.16; P = 0.037), but not in the Octogenarians subgroup (P = 0.119). CONCLUSIONS Preoperative age ≥80 years is not associated with worse outcomes postoperatively after isolated elective total arch replacement with mild hypothermic lower body circulatory arrest and bilateral antegrade selective cerebral perfusion.

Acid-base Management in Cardiopulmonary Bypass

Cardiopulmonary bypass (CPB) merupakan alat penunjang fungsi sirkulasi dan pernapasan pasien yang biasa digunakan ketika menjalani pembedahan jantung atau pembuluh darah besar. Selama prosedur CPB, kondisi hipotermia dipertahankan untuk menurunkan kebutuhan oksigen dan laju metabolisme. Kondisi hipotermia akan mempengaruhi keseimbangan asam-basa pada tubuh. Manajemen asam-basa selama prosedur CPB dicapai dengan menggunakan metode a-stat atau pH-stat. Pada metode a-stat, manajemen asam-basa dilakukan dengan menjaga pHa 7.4 dan PaCO2 40 mmHg pada suhu 37oC tanpa penambahan CO2 oksigen untuk menjaga total CO2 tetap konstan. Sedangkan, pada metode pH-stat, diberikan CO2 oksigen untuk menjaga PaCO2 40 mmHg dan pHa 7.4 secara in vivo. Masih banyak perdebatan terkait waktu penerapan masing-masing metode. Pada level mikrosirkulasi, manajemen a-stat terbukti memberikan keuntungan pada otak dan mengurangi insidensi postoperative cerebral dysfunction. Sedangkan, metode pH-stat dilaporkan meningkatkan risiko emboli otak, sehingga tidak disarankan untuk pasien yang memiliki risiko tinggi gangguan aliran darah otak. Namun, terdapat pula laporan yang menyatakan pH-stat bermanfaat pada operasi bedah jantung anak. Berdasarkan hal itu, usia pasien dapat menentukan waktu penggunaan metode a-stat dan pH-stat. Satu indikasi primer penggunaan pH-stat adalah selama proses pendinginan saat deep hypothermic circulatory arrest (DHCA), sedangkan metode a-stat lebih baik digunakan selama selective cerebral perfusion (SCP) dan rewarming.

Ensure an “Ultrasound Window” on the Patient's Neck to Evaluate Cerebral Blood Flow!

Near-infrared spectroscopy (NIRS) does not provide information about changes in oxygenation in whole-brain areas. Although the branching vessels of the aortic arch are not always easy to identify using transesophageal echocardiography (TEE), the blood flow status of cervical arteries can always be assessed by applying an ultrasound probe via the “ultrasound window” on the patient's neck, which can be ensured by devising alternative insertion approaches of the central venous catheter. This method is very simple but compensates for the limitations of the combination of NIRS and TEE, especially during cardiac surgery with cardiopulmonary bypass management using selective cerebral perfusion.

Effects of circulatory arrest and cardiopulmonary bypass on cerebral autoregulation in neonatal swine

Background Cerebral autoregulation mechanisms help maintain adequate cerebral blood flow (CBF) despite changes in cerebral perfusion pressure. Impairment of cerebral autoregulation, during and after cardiopulmonary bypass (CPB), may increase risk of neurologic injury in neonates undergoing surgery. In this study, alterations of cerebral autoregulation were assessed in a neonatal swine model probing four perfusion strategies. Methods Neonatal swine (n = 25) were randomized to continuous deep hypothermic cardiopulmonary bypass (DH-CPB, n = 7), deep hypothermic circulatory arrest (DHCA, n = 7), selective cerebral perfusion (SCP, n = 7) at deep hypothermia, or normothermic cardiopulmonary bypass (control, n = 4). The correlation coefficient (LDx) between laser Doppler measurements of CBF and mean arterial blood pressure was computed at initiation and conclusion of CPB. Alterations in cerebral autoregulation were assessed by the change between initial and final LDx measurements. Results Cerebral autoregulation became more impaired (LDx increased) in piglets that underwent DH-CPB (initial LDx: median 0.15, IQR [0.03, 0.26]; final: 0.45, [0.27, 0.74]; p = 0.02). LDx was not altered in those undergoing DHCA (p > 0.99) or SCP (p = 0.13). These differences were not explained by other risk factors. Conclusions In a validated swine model of cardiac surgery, DH-CPB had a significant effect on cerebral autoregulation, whereas DHCA and SCP did not. Impact Approximately half of the patients who survive neonatal heart surgery with cardiopulmonary bypass (CPB) experience neurodevelopmental delays. This preclinical investigation takes steps to elucidate and isolate potential perioperative risk factors of neurologic injury, such as impairment of cerebral autoregulation, associated with cardiac surgical procedures involving CPB. We demonstrate a method to characterize cerebral autoregulation during CPB pump flow changes in a neonatal swine model of cardiac surgery. Cerebral autoregulation was not altered in piglets that underwent deep hypothermic circulatory arrest (DHCA) or selective cerebral perfusion (SCP), but it was altered in piglets that underwent deep hypothermic CBP.

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 &lt; 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.

Modified Isolated Cerebral Perfusion Technique for Prevention of Stroke With Aortic Arch Replacement

In aortic arch replacement, an isolated cerebral perfusion method has been reported in additional to axillary artery cannulation to prevent postoperative stroke. We have made changes to this method. In other words, we devised a method to reduce cerebral embolism by performing selective cerebral perfusion via an artificial graft anastomosed to the left common carotid artery and the left subclavian artery. This method was performed in 7 cases, and all patients were discharged alive without any neurological disorders. In the surgical procedure of the aortic arch, sufficient care must be taken in the manipulation around the brachiocephalic artery and the left subclavian artery. Our method can avoid reinsertion due to desorption of the cerebral perfusion cannula and can be expected to prevent postoperative stroke.