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.

Aortic Dissection Detection Risk Score and D-Dimer for Acute Aortic Syndromes in the Chinese Population: Exploration of Optimal Thresholds and Integrated Diagnostic Value.

This study aimed to assess the diagnostic performance of the aortic dissection detection risk score (ADD-RS) plus D-dimer for acute aortic syndrome (AAS) in Chinese patients. Two hundred and sixty-two and 200 patients with suspected AAS symptoms were enrolled as exploration cohort and validation cohort, respectively. In exploration cohort, ADD-RS plus D-dimer (AUC = 0.929, 95%CI: 0.887-0.971) presented a better diagnostic value for AAS than ADD-RS or D-dimer alone. Meanwhile, ADD-RS > 1 and D-dimer > 2000 ng/mL were the optimal thresholds. Then, a diagnostic model integrating ADD-RS > 1 plus D-dimer > 2000 ng/mL was established, presenting sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 92.5%, 70.3%, 34.9%, and 98.2%, respectively. In validation cohort, the established diagnostic model exhibited a sensitivity, specificity, PPV, and NPV of 93.1%, 70.2%, 34.6%, and 98.4%, respectively, for diagnosing AAS. Summarily, ADD-RS > 1 and D-dimer > 2000 ng/mL are optimal thresholds for diagnosing AAS in the Chinese population. However, confirmative MSCT results are necessary.

ECPR successfully used in 5.5-hour cardiac arrest caused by peripartum cardiomyopathy: a case report and minireview.

Background: Cardiac arrest (CA) caused by peripartum cardiomyopathy (PPCM) is a catastrophic disease that can lead to a high mortality rate in young women. Cardiopulmonary resuscitation (CPR) is the initial first aid measure to be taken and unfortunately, does not always lead to the restoration of spontaneous circulation (ROSC). We shared a rare successful case of extracorporeal cardiopulmonary oxygenation-assisted resuscitation (ECPR) in a patient with CA for up to 5.5 hours due to PPCM. Case Description: A previously healthy 31-year-old woman at 34 weeks of gestation was admitted to the emergency department with fever and arrhythmia. Two days later, the patient had postpartum CA. She underwent CPR for up to 5 hours before receiving V-A extracorporeal membrane oxygenation (ECMO) support and eventually regained spontaneous circulation after half an hour. Based on the clinical manifestations, the patient was diagnosed with PPCM and received treatment. The patient was successfully removed from ECMO after 9 days. The patient experienced ECMO-related complications, including thrombocytopenia and intracranial hemorrhage (ICH). Although treatment was difficult, the patient was discharged after 2 months without any neurological complications. We followed up for 1 year and the patient was able to work normally as a teacher. In our mini-review, we found that the success rate of ECPR in perinatal CA was high, and ECPR is worthy of promotion and application. Conclusions: As an advanced life support method, ECPR can save patients undergoing postpartum CA. However, effective CPR and avoidance of ICH are necessary for the recovery of brain function.

Th1, Th2, and Th17 cells are dysregulated, but only Th17 cells relate to C-reactive protein, D-dimer, and mortality risk in Stanford type A aortic dissection patients.

BACKGROUND: T helper (Th) cells are closely involved in vascular inflammation, endothelial dysfunction, and atherogenesis, which are the hallmarks of aortic dissection (AD). This study aimed to evaluate the clinical value of Th1, Th2, and Th17 cell measurements in Stanford type A AD patients. METHODS: Stanford type A AD patients (N=80) and non-AD patients with chest pain (N = 40) were recruited. Then, Th1, Th2, and Th17 cells in peripheral blood CD4+ T cells from all participants were detected by flow cytometry. The 30-day mortality of Stanford type A AD patients was recorded. RESULTS: Th1 and Th17 cells were higher, while Th2 cells were lower in Stanford type A AD patients compared with non-AD patients (all p < 0.001). Meanwhile, Th1 cells (area under curve (AUC): 0.734, 95% confidence interval (CI): 0.640-0.828), Th2 cells (AUC: 0.841, 95% CI: 0.756-0.925), and Th17 cells (AUC: 0.898, 95% CI: 0.839-0.957) could distinguish Stanford type A patients from non-AD patients. Moreover, Th1 cells (p = 0.037) and Th17 cells (p = 0.001) were positively related to CRP, and Th17 cells (p = 0.039) were also positively associated with D-dimer in Stanford type A AD patients. Furthermore, Th17 cells were elevated in deaths compared with survivors (p = 0.001), also, it could estimate 30-day mortality risk in Stanford type A AD patients with an AUC of 0.741 (95% CI: 0.614-0.867), which was similar to the value of CRP (AUC: 0.771, 95% CI: 0.660-0.882), but lower than the value of D-dimer (AUC: 0.818, 95% CI: 0.722-0.913). CONCLUSION: Th1, Th2, and Th17 cells are dysregulated, but only the Th17 cells relate to CRP, D-dimer, and 30-day mortality risk in Stanford type A AD patients.

Cannulation strategies in type A aortic dissection: a novel insight narrative review.

This review highlights vital details that can be easily overlooked and discuss how to identify and fix failed cannulation from another novel insight. Appropriate arterial cannulation strategy during cardiopulmonary bypass (CPB) in Stanford type A aortic dissection (AAD) is highly necessary to reach satisfactory perfusion effects and appreciable clinical outcomes. Despite several previously published reviews on cannulation strategies in AAD, most focus on the advantages and disadvantages by comparing various cannulation strategies. In fact, most of evidence came from retrospective studies. More importantly, however, some important details and novel approaches maybe overlooked due to variety reasons. These overlooked details also make sense in clinical practice. Papers related to cannulation refer to type AAD were retrieved and analyzed from the PubMed and Medline database. The key words such as "aortic dissection", "cannula", "cannulation", "cannulation strategy", "cerebral perfusion", "type I aortic dissection" were conducted and analyzed. In addition, we looked at some new and very significant specific perfusion techniques such as anterograde cerebral perfusion combined with retrograde inferior vena caval perfusion (RIVP) and reperfusion via the right carotid artery before surgery. The arterial cannulation site and strategy should be determined individually. Monitoring measures are very necessary in the whole procedure.

Computational numerical analysis of different cannulation methods during cardiopulmonary bypass of type A aortic dissection model based on computational fluid dynamics.

BACKGROUND: The aim of the present study was to use a numerical simulation based on computational fluid dynamics (CFD) to analyze the difference of different cannulation methods on hemodynamics characteristic in a type A aortic dissection (TAAD) model. METHODS: A finite-element analysis based on the CFD model of a TAAD patient was used, and axillary artery cannulation (AAC), innominate artery cannulation (IAC), and femoral artery cannulation (FAC) were analyzed under different situations, including a cardiac output (CO) of 2.5 L/min and cardiopulmonary bypass (CPB) of 2.5 L/min (partial CPB before cross-clamping aorta, defined as condition A), and a CO of 0 L/min and CPB of 5 L/min (aortic cross-clamping phase, defined as condition B). The insertion of an 8-mm cannula into the different models was simulated. Hemodynamic characteristics, including wall shear stress, wall stress, blood flow, and velocity were analyzed. RESULTS: In condition A, the total flow of branches of the aortic arch was 2,009.5 mL/min (AAC), 1,855.47 mL/min (IAC), and 1,648.03 mL/min (FAC). All cannulation methods improved left renal blood perfusion. However, in relation to blood flow in the right renal artery, FAC showed the highest blood flow (105 mL/min). The results in condition B were similar to those of condition A. The velocity, shear stress, and stress of entry tear via AAC and IAC decreased in condition B compared with condition A. The velocity, shear stress, stress of tear via AAC was lower than that of IAC. CONCLUSIONS: Different cannulation modes have an effect on the hemodynamic characteristic of the tear, but this effect is related to different states of CPB. AAC was found to superior to IAC, especially in reducing velocity, stress, and shear stress of site of tear. However, IAC and AAC are more conductive to blood supply than FAC in branch vessels of the aortic arch without being affected by the CPB state.

Awake veno-arterial extracorporeal membrane oxygenation in patients with perioperative period acute heart failure in cardiac surgery.

BACKGROUND: Extracorporeal membrane oxygenation (ECMO) is an effective extracorporeal life support technology that has been applied to treat cardiorespiratory failure patients. Some medical centers have started using ECMO on awake, non-intubated, spontaneously breathing patients, as this strategy offers several benefits over mechanical ventilation. However, most awake-ECMO methods focus on venovenous ECMO, and few cases of awake veno-arterial ECMO (V-A ECMO) have been reported, especially in perioperative acute heart failure. Therefore, our study aimed to examine awake-V-A ECMO cases that were not given continuous sedation or invasive mechanical ventilation (IMV) during perioperative heart failure. METHOD: In total, 40 ECMO patients from December 2013 to November 2019 were divided into 2 groups (the awake-ECMO group and the asleep-ECMO group) according to the ventilation use. The demographics, patient outcomes, and ECMO parameters were collected and retrospectively analyzed. RESULTS: We identified 12 cases of awake ECMO without continuous ventilation, and 28 cases of simultaneous IMV and ECMO (asleep ECMO). Awake-ECMO patients showed fewer complications and better outcomes compared to ventilation patients. All patients in the awake group were successfully weaned off ECMO, while only 5 (18%) patients were weaned off ECMO in the asleep group. Furthermore, 9 (75%) patients survived until discharge in the awake group vs. 3 (11%) in the asleep group; 3 patients died of septic shock after weaning in the awake group, while 25 patients died of septic shock, hemodynamic disorder, bleeding, cerebral hemorrhage, etc., in the asleep group. These complications, including bleeding, pneumonia, hemolysis, and abdominal distension, etc., occurred less frequently in the asleep group compared to the awake group (P<0.05). CONCLUSIONS: Awake V-A ECMO is an effective, feasible, and safe strategy in patients with perioperatively acute heart failure and can be applied as a bridge to cardiac function recovery or transplantation.

[Influence of exogenous gamma-aminobutyric acid (GABA) on GABA metabolism and amino acid contents in roots of melon seedling under hypoxia stress].

This paper investigated the influence of gamma-aminobutyric acid (GABA) on GABA metabolism and amino acid content under hypoxia stress by accurately controlling the level of dissolved oxygen in hydroponics, using the roots of melon 'Xiyu 1' seedlings as the test material. The results showed that compared with the control, the growth of roots was inhibited seriously under hypoxia stress. Meanwhile, the hypoxia-treated roots had significantly higher activities of glutamate decarboxylase (GAD), glutamate dehydrogenase (GDH), glutamate synthase (GOGAT), glutamine synthetase (GS), alanine aminotransferase (ALT), aspartate aminotransferase (AST) as well as the contents of GABA, pyruvic acid, alanine (Ala) and aspartic acid (Asp). But the contents of glutamic acid (Glu) and alpha-keto glutaric acid in roots under hypoxia stress was obviously lower than those of the control. Exogenous treatment with GABA alleviated the inhibition effect of hypoxia stress on root growth, which was accompanied by an increase in the contents of endogenous GABA, Glu, alpha-keto glutaric acid and Asp. Furthermore, under hypoxia stress, the activities of GAD, GDH, GOGAT, GS, ALT, AST as well as the contents of pyruvic acid and Ala significantly decreased in roots treated with GABA. However, adding GABA and viny-gamma-aminobutyric acid (VGB) reduced the alleviation effect of GABA on melon seedlings under hypoxia stress. The results suggested that absorption of GABA by roots could alleviate the injury of hypoxia stress to melon seedlings. This meant that GABA treatment allows the normal physiological metabolism under hypoxia by inhibiting the GAD activity through feedback and maintaining higher Glu content as well as the bal- ance of carbon and nitrogen.

[Effects of exogenous gamma-aminobutyric acid on polyamine metabolism of melon seedlings under hypoxia stress].

Taking melon cultivar 'Xiyu No. 1 ' as test material, a hydroponic experiment was conducted to investigate the effects of exogenous gamma-aminobutyric acid (GABA) on the seedlings polyamine metabolism under hypoxia stress. Compared with the control in normoxic treatment, the seedlings under hypoxia stress had significantly higher glutamic acid decarboxylase (GAD) activity and GABA content, and their polyamine synthesis enzymes activities all enhanced significantly, which led to a marked increase of polyamines contents. Meanwhile, the seedlings leaf- and root diamine oxidase (DAO) and polyamine oxidase (PAO) activities also had a significant increase. The increment of root arginine decarboxylase (ADC) activity was higher, which induced a higher content of free putrescine (Put) in roots, while the increment of leaf ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (SAMDC) activities were higher, inducing a higher content of free spermidine (Spd) in leaves. The PBs-extractable DAO and PAO activies in roots were significantly lower than those in leaves, but the cell wall-bound PAO activity was in adverse. Under hypoxia stress, the addition of exogenous GABA increased the leaf- and root GABA and glutamic acid contents and decreased the GAD activity significantly. The increase of arginine, ornithine, and methionine contents promoted the activities of polyamines synthesis enzymes, which led to the significant increase of polyamines contents and the significant decrease of DAO and PAO activities.

[Effects of gamma-aminobutyric acid on the photosynthesis and chlorophyll fluorescence parameters of muskmelon seedlings under hypoxia stress].

By the method of hydroponic culture, this paper studied the effects of exogenous gamma-aminobutyric acid (GABA) on the photosynthetic pigment contents, photosynthesis, and chlorophyll fluorescence parameters of muskmelon seedlings under hypoxia stress. Hypoxia stress induced a significant decrease of photosynthetic pigment contents, resulting in the decrease of photosynthesis. Applying GABA could significantly increase the photosynthetic pigment contents, net photosynthetic rate (P(n)), stomatal conductance (G(s)), intercellular CO2 concentration (C(i)), carboxylation efficiency (CE), maximal photochemical efficiency of PS II (F(v)/F(m)), photochemical quenching (q(P)), apparent photosynthetic electron transfer rate (ETR), and quantum yield of PS II electron transport (phi(PS II)), and decrease the stomatal limitation value (L(s)), minimal fluorescence (F(o)), and non-photochemical quenching (NPQ) under both hypoxic and normal conditions. The alleviation effect of GABA on photosynthetic characteristics was more obvious under hypoxia stress. However, simultaneously applying GABA and VGB could significantly decrease the alleviation effect of GABA under hypoxia stress.