Moderate Hypothermic Circulatory Arrest Research Articles

Results of using thoraflextm hybrid prothesis for the treatment of complex aortic disease at Viet Duc University Hospital

Background: The aim of this study was to introduce and evaluate the early results after the frozen elephant trunk (FET) procedure with ThoraflexTM Hybrid prothesis for the treatment of complex aortic disease at Viet Duc University Hospital. Methods: This is a retrospective descriptive study of all acceptable patients after the frozen elephant trunk (FET) procedure with ThoraflexTM Hybrid prothesis at Viet Duc University Hospital from January 2021 to May 2023. Results: There were 21 patients with a male rate of 85.7% and an average age 58.2±10 years old (range 40–73). History of patients with hypertension: 19 (90.5%); post-dissection aortic aneurysm: 2 (9.5%) patients. By cause, the number of patients with thoracic aortic aneurysm was 03 (14.3%), acute aortic dissection type A was 16 (76.1%), and aortic dissection type B was 02 (9.5%). In which there were 16 cases of emergency surgery (76.1%). Replacement of the aortic arch was performed under moderate hypothermic (280 °C on average) circulatory arrest and bilateral selective antegrade cerebral perfusion with permanent monitoring of cerebral tissue oxygenation by the MASIMO machine. Average cardio-pulmonary bypass time, aortic cross clamp time, distal hypothermic circulatory arrest time, and operating time were 137,5±22,9 minutes; 86,3±17,6 minutes; 25,2±8,9 minutes; and 7,7±10,3 hours. The average ventilation time, length of intensive care unit stay, and hospital stay were 7,2±9,7 days, 18,8±20,7 days, and 19,9 ± 6,5 days. There was one patient with post-operative cerebrospinal fluid drainage. No patient had bleeding complications, recurrent nerve palsy, reoperation, or in-hospital mortality. Conclusion: The initial results after the frozen elephant trunk procedure with ThoraflexTM Hybrid prothesis for the treatment of complex aortic disease at Viet Duc University Hospital were safe, good, and feasible.

Exploring Differences in Surgical Outcomes Depending on the Arterial Cannulation Strategy for Acute Type A Aortic Dissection: A Single-Center Study.

Type A aortic dissection (AD) and intramural hematoma (IMH) are critical medical conditions. Emergency surgery is typically performed under cardiopulmonary bypass immediately after diagnosis, which involves lowering the body temperature to induce total circulatory arrest. Selection of the arterial cannulation site is a critical consideration in cardiac surgery and becomes more challenging in patients with AD. This study explored the strengths and weaknesses of different cannulation methods by comparing each cannulation strategy and analyzing the reasons for patients' outcomes, especially mortality and cerebrovascular accidents (CVAs). This retrospective study reviewed the medical records of patients who underwent surgery for type A AD or IMH between 2008 and 2023, using the moderate hypothermic circulatory arrest approach at a single center. Among the 146 patients reviewed, 32 underwent antegrade cannulation via axillary, innominate artery, aortic, or transapical cannulation, while 114 underwent retrograde cannulation via the femoral artery. The analysis of surgical outcomes revealed a significant difference in the total surgical time, with 356 minutes for antegrade and 443 minutes for retrograde cannulation (p<0.001). The mean length of stay in the intensive care unit was significantly longer in the retrograde group (5±16 days) than in the antegrade group (3±5 days, p=0.013). Nevertheless, no significant difference was found between the groups in the 30-day mortality or postoperative CVA rates (p=0.2 and p=0.7, respectively). Surgeons should consider an appropriate cannulation strategy for each patient instead of adhering strictly to a specific approach in AD surgery.

Optimal antegrade cerebral perfusion flow in patients undergoing surgery for acute type A aortic dissection: A retrospective single-center analysis.

Systemic hypothermia with bilateral antegrade selective cerebral perfusion (ASCP) is the preferred cerebral protective strategy for type A aortic dissection surgery. The optimal ASCP flow rate remains uncertain and the target flow cannot always be reached due to pressure limitations. The aim of this study was to assess the correlation between ASCP flow and regional cerebral oxygen saturation (rSO2). A retrospective analysis was performed on 140 patients with acute type A aortic dissection who underwent surgery with moderate hypothermic circulatory arrest and bilateral ASCP between 2015 and 2021. Pearson correlation analysis was performed between ASCP flow and rSO2. The median circulatory arrest duration was 46.5 (IQR:37.0-61.0) minutes. There was no significant correlation between ASCP flow and rSO2 for both the right (r = -.02, p = .851), and the left hemisphere (r = - .04, p = .618). The rSO2 values for ten patients who received > 10mL/kg/min flow did not differ significantly from 130 patients who received 10mL/kg/min or less for both the left hemisphere (p = .135), and the right hemisphere (p = .318). The ASCP flow was 5.1 (IQR:5.0- 6.5) mL/kg/min in five patients with, and 7.2 (IQR:5.8-8.3) mL/kg/min in 135 patients without a watershed infarction (p = .098). There was no correlation between ASCP flow rate and rSO2 in patients with acute type A aortic dissection. Furthermore, ASCP flow below 10mL/kg/min was not associated with a reduction in rSO2. Definitive associations between ASCP flow and neurological outcome after type A aortic dissection surgery need further investigation.

The Learning Curve of Total Arch Replacement via Single Upper Hemisternotomy Approach in Aortic Dissection.

Upper hemisternotomy (UHS) has benefits over conventional full sternotomy because it ameliorates trauma during cardiac surgery. Owing to its challenging and technically demanding nature, this incision in acute type A aortic dissection (ATAAD) has rarely been reported. This study aimed to analyze the learning curve of total arch replacement (TAR) with moderate hypothermic circulatory arrest via a single UHS approach, which is necessary to guide the training of surgeons in adopting minimally invasive procedures. A total of 202 consecutive patients who were definitively diagnosed with ATAAD between July 2016 and June 2021 were enrolled in this retrospective analysis. Patients were divided into three groups based on cumulative sum plots for circulatory arrest time in chronological order. Perioperative characteristics were compared between the groups. There was significant difference in the circulatory arrest time and cross-clamp time respectively among three groups (39.0 min vs 28.0 min vs 15.0 min, P < 0.001; 104.5 min vs 106.2 min vs 84.1 min, P < 0.001). The ventilation time and first 24-h chest tube drainage were statistically different among groups (35.5 h vs 24.0 h vs 19.0 h, P = 0.031; 220.0 mL vs 192.5 mL vs 125.5 mL, P = 0.043). No other clinical outcome was observed as significant difference. A cardiac surgeon can convert a conventional full sternotomy to a single UHS for TAR after experiencing a learning curve, to ensure patient safety. The mastery of this minimally invasive surgical technique may be beneficial for the prognosis of patients with ATAAD.

Risk Factors for Acute Kidney Injury after Moderate Hypothermic Circulatory Arrest in Hemiarch Replacement

Background. The aim of this study was to clarify the incidence and risk factors for acute kidney injury (AKI) in patients undergoing hemiarch replacement (HAR) under moderate hypothermic circulatory arrest (MHCA) with retrograde cerebral perfusion (RCP). Methods. We retrospectively analyzed patients who underwent HAR under MHCA with RCP at our institution between April 2015 and July 2022. Exclusion criteria were preoperative dialysis, single kidney, and lack of preoperative plasma creatinine data. The study endpoint was the incidence of postoperative AKI, defined using the Kidney Disease: Improving Global Outcomes criteria. Multivariate logistic regression analysis was performed to identify the risk factors for postoperative AKI. Results. One hundred and seventy-nine patients were included in this study. The most common indications for HAR were thoracic aortic aneurysm (n = 107) and acute aortic dissection (n = 57). Concomitant procedures, most frequently aortic valve surgery, were performed in 104 (60.5%) patients. Median circulatory arrest time and minimum rectal temperature were 15 minutes (interquartile range, 11 to 19) and 27.4°C (interquartile range, 25.9 to 28.1), respectively. Operative mortality was 1.1%. The incidence of postoperative AKI was 37.8%. Multivariate analysis showed that acute aortic dissection (odds ratio, 4.57; 95% confidence interval (CI), 2.13–10.14; P &lt; 0.001) and longer operating time (odds ratio, 1.01; 95% CI, 1.00-1.01; P = 0.001) were independent predictors for postoperative AKI. Conclusions. Acute aortic dissection and longer operating time were risk factors for postoperative AKI in patients undergoing HAR under MHCA with RCP. In contrast, neither circulatory arrest time nor minimum rectal temperature was a risk factor for AKI. This may be due to the short duration of circulatory arrest.

Neuroprotection and Classification of Neurologic Dysfunction in Aortic Arch Surgery: A Narrative Review

Open aortic arch surgery incurs frequent neurologic complications and high mortality. The disease processes of aortic aneurysm and acute aortic dissection, and the physiological trespass of cardiopulmonary bypass and hypothermic circulatory arrest (CA), can engender neurologic dysfunction such as postoperative stroke and delirium. While deep hypothermic CA (with and without retrograde cerebral perfusion) is the major strategy for brain protection, moderate hypothermic CA with antegrade cerebral perfusion has comparable or better outcomes. Classes of neurologic complications in aortic arch surgery were defined three decades ago. In 2021, the Valve Academic Research Consortium recommended new endpoints for assessing neurologic outcomes of transcatheter and surgical aortic valve procedures. Those parameters include neuroimaging biomarkers. Overt central nervous system (CNS) injury is the severe form and delirium is the common clinical presentation. Covert CNS injury, evidenced on brain imaging, is prevalent in patients following transcatheter aortic valve replacement (TAVR). The new definition for neurologic dysfunction after TAVR could serve in the classification of neurologic dysfunction in aortic arch surgery.

Incidence and clinical impact of silent pancreatitis after aortic arch surgery.

This study was designed to investigate the incidence and types of pancreatic injury, risk factors, and time-course changes in computed tomographic findings following total aortic arch replacement with moderate hypothermic circulatory arrest. Medical records of patients who underwent total arch replacement between January 2006 and August 2021 were retrospectively reviewed. A comparison study between the patients with (group P) and without pancreatic injury (group N) was conducted to elucidate the impact of pancreatic injury. Follow-up computed tomography of the patients in group P was reviewed to investigate time-course changes of the pancreatic injury. Of 353 patients, 14 (4.0%) had subclinical pancreatic injury. Computed tomographic findings were consistent with acute pancreatitis in all patients, of whom eight patients had interstitial edematous pancreatitis, whereas six patients had necrotizing pancreatitis. Although walled-off necrosis occurred in three patients, none of them required drainage. In-hospital mortality was 7.1% and 4.4% in groups P and N, respectively (p = 0.98). The 5-year actuarial survival rates were 77.9% and 81.0% in groups P and N, respectively (p = 0.51). Multivariate analysis revealed that pancreatic injury was associated with chronic obstructive pulmonary disease (p = 0.03). This study highlighted that silent pancreatic injury after aortic arch surgery is underrecognized. Potential arterial sclerosis of the pancreatic circulation seems to be related to pancreatic injury.

Temperature analysis of aortic repair with hypothermic circulatory arrest to quantify the injury by cooling

We analyzed the temperature in proximal aortic repair with moderate hypothermic circulatory arrest (HCA) and evaluated the effect of the cooling status on postoperative outcomes. A total of 340 patients who underwent elective ascending aortic replacement or total arch replacement with moderate HCA from December 2006 to January 2021 were studied. The change in body temperature trends recorded during surgery was shown graphically. Several parameters, such as the nadir temperature, cooling speed and the degree of cooling (cooling area), which was the area under curve of inverted temperature trends from cooling to rewarming as calculated by the integral method, were analyzed. The relationships between these variables and a major adverse outcome (MAO) postoperatively defined as prolonged ventilation (>72 h), acute renal failure, stroke, reoperation for bleeding, deep sternal wound infection or in-hospital death were evaluated. An MAO was observed in 68 patients (20%). The cooling area was larger in the MAO group than in the non-MAO group (1668.7 vs 1383.2°C min; P < 0.0001). A multivariate logistic model showed that old myocardial infarction, peripheral vascular disease, chronic renal dysfunction, cardiopulmonary bypass time and the cooling area were independent risk factors for an MAO (odds ratio = 1.1 per 100°C min; P < 0.001). The cooling area, which indicates the degree of cooling, shows a significant relationship with an MAO after aortic repair. This finding indicates that the cooling status with HCA can affect clinical outcomes.

Clinical outcomes of mild versus moderate hypothermic circulatory arrest with antegrade cerebral perfusion in adult aortic arch surgery: A systematic review and meta-analysis.

In adult aortic arch surgery, moderate hypothermic circulatory arrest (HCA) with selective antegrade cerebral perfusion (SACP) (MoHACP) is widely used, but the application of mild HCA with SACP (MiHACP) is still controversial. This meta-analysis aimed to compare clinical outcomes using MiHACP or MoHACP. Studies comparing outcomes of MiHACP or MoHACP in adult aortic arch surgery were searched from four databases from inception through April 2022. Primary outcomes were postoperative permanent neurological deficit (PND), temporary neurological deficit (TND), and mortality. Secondary outcomes included other common complications. Meta-analysis was conducted using a random-effects model in all cases. Eleven comparative studies were included, with 1555 patients in MiHACP group and 1499 patients in MoHACP group, and the mean HCA temperature were 29.4°C and 24.8°C, respectively. Postoperative PND, TND, mortality, paraplegia, dialysis, tracheotomy, reexploration for bleeding, and chest tube drainage volume were comparable in the two groups (p > 0.05). Ventilator time, intensive care unit and in-hospital length of stay were shorter in MiHACP group (p < 0.05). Outcomes were also comparable or had some benefits in MiHACP group when subgroup analyses were conducted according to hemiarch or total arch replacement, unilateral or bilateral SACP, HCA time, emergency aortic dissection surgery, and concomitant procedure. The present meta-analysis showed acceptability of MiHACP in adult aortic arch surgery. Results need to be taken with caution as moderate risk of bias and very low quality of evidence were observed in this meta-analysis. Randomized controlled trials are needed for further analysis.

Deep versus Moderate Hypothermia inAcute Type A Aortic Dissection: APropensity-Matched Analysis.

The ideal temperature for hypothermic circulatory arrest (HCA) during acute type A aortic dissection (ATAAD) repair has yet to be determined. We examined the clinical impact of different degrees of hypothermia during dissection repair. Out of 240 cases of ATAAD between June 2014 and December 2019, 228 patients were divided into two groups according to lowest intraoperative temperature: moderate hypothermic circulatory arrest (MHCA) (20-28°C) versus deep hypothermic circulatory arrest (DHCA) (<20°C). From this, 74 pairs ofpropensity-matched patients were analysed with respect to operative data and short-term clinical outcomes. Independent predictors of a composite outcome of 30-day mortality and stroke were identified. Mean lowest temperature was 25.5±3.9°C in the MHCA group versus 16.0±2.9°C in DHCA. Overall 30-day mortality of matched cohort was 11.5% (17 deaths), not significantly difference between matched groups. Cardiopulmonary bypass (CPB) times were longer in DHCA (221.0±69.9 vs 190.7±74.5 mins, p=0.01). Antegrade cerebral perfusion (ACP) during HCA predicted a lower composite risk of 30-day mortality and stroke (OR 0.38). Female sex (OR 4.71), lower extremity ischaemia at presentation (OR 3.07), and CPB >235 minutes (OR 2.47), all portended worse postoperative outcomes. A surgical strategy of MHCA is at least as safe as DHCA during repair of acute type A aortic dissection. ACP during HCA is associated with reduced 30-day mortality and stroke, whereas female sex, lower extremity ischaemia, and longer CPB times are all predictive of poorer short-term outcomes.

Optimal temperature management in aortic arch surgery: A systematic review and network meta-analysis.

New temperature management concepts of moderate and mild hypothermic circulatory arrest during aortic arch surgery have gained weight over profound cooling. Comparisons of all temperature levels have rarely been performed. We performed direct and indirect comparisons of deep hypothermic circulatory arrest (DHCA) (≤20°C), moderate hypothermic circulatory arrest (MHCA) (20.1-25°C), and mild hypothermic circulatory arrest (mild HCA) (≥25.1°C) in a network meta-analysis. The literature was systematically searched for all papers published through February 2022 reporting on clinical outcomes after aortic arch surgery utilizing DHCA, MHCA and mild HCA. The primary outcome was operative mortality. The secondary outcomes were postoperative stroke and acute kidney failure (AKI). A total of 34 studies were included, with a total of 12,370 patients. DHCA was associated with significantly higher postoperative incidence of stroke when compared with MHCA (odds ratio [OR], 1.46, 95% confidence interval[CI], 1.19-1.78) and mild HCA: (OR, 1.50, 95% CI, 1.14-1.98). Furthermore, DHCA and MHCA were associated with higher operative mortality when compared with mild HCA (OR 1.71, 95% CI, 1.23-2.39 and OR 1.50, 95% CI, 1.12-2.00, respectively). Separate analysis of randomized and propensity score matched studies showed sustained increased risk of stroke with DHCA in contrast to MHCA and mild HCA (OR, 1.61, 95% CI, 1.18-2.20, pvalue = .0029 and OR, 1.74, 95% CI, 1.09-2.77, pvalue = .019). In the included studies, the moderate to mild hypothermia strategies were associated with decreased operative mortality and the risk of postoperative stroke. Large-scale prospective studies are warranted to further explore appropriate temperature management for the treatment of aortic arch pathologies.

Safety and efficacy of fibrinogen concentrate in aortic arch surgery involving moderate hypothermic circulatory arrest.

Bleeding is a common complication of cardiac surgery, especially aortic arch surgery involving moderate hypothermic circulatory arrest. Fibrinogen concentrate has been increasingly used to treat coagulopathic bleeding in cardiac surgery, although its effectiveness and safety are unknown. The aim of this prospective study was to investigate the safety and efficacy of fibrinogen concentrate in patients with acute type A aortic dissection. From July 2020 to August 2021, 84 patients with acute type A aortic dissection who underwent emergency aortic arch surgery involving MHCA and whose intraoperative fibrinogen level was less than 1.5g/L were included in this study. Fifty-four patients who were supplemented with fibrinogen concentrate were included in the FC treatment group. Thirty patients were included in the non-FC treatment group. The primary endpoints included the required volumes of individual allogeneic blood products (RBCs, FFP, and PC), volumes of cumulative drainage within 24 and 48h, and total volumes after infusion of FC, as well as reoperation rates due to bleeding. The secondary endpoint for the study was the incidence of serious adverse events from the infusion of FC to day 45. The serious adverse events defined for the evaluation of the safety of FC were death, pulmonary embolism and other thromboembolic or ischaemic events. The clinical data, routine laboratory tests and plasma fibrinogen levels were obtained at 5 time points. We observed rapid increases in the plasma fibrinogen level and subsequent improvement in haemostasis after the administration of fibrinogen concentrate. The mean fibrinogen level increased from 1.36 ± 0.75g/L to 2.91 ± 0.76g/L in the fibrinogen concentrate treatment group. The patients in the fibrinogen concentrate treatment group demonstrated lower volumes of cumulative postoperative drainage and transfused allogeneic blood products than the nonfibrinogen concentrate treatment group. There were no serious adverse events in the fibrinogen concentrate treatment group during hospitalization. Fibrinogen concentrate was effective at increasing the plasma fibrinogen level and significantly reduced the volumes of transfused allogeneic blood products and blood loss in patients with aortic arch surgery. There were no serious adverse events in the patients who received fibrinogen concentrate treatment. The safety and efficacy of fibrinogen concentrate were investigated in acute type A aortic dissection patients with aortic arch surgery. Fibrinogen concentrate was effective at increasing the plasma fibrinogen level and significantly reduced the volumes of transfused allogeneic blood products and blood loss; there were no serious adverse events in the patients who received fibrinogen concentrate treatment.

Modification of pulmonary endarterectomy to prevent neurologic adverse events.

Neurologic adverse events (NAEs) are a major complication after pulmonary endarterectomy (PEA) performed under periods of deep hypothermic circulatory arrest (HCA) for chronic thromboembolic pulmonary hypertension. We modified the PEA strategy to prevent NAEs and evaluated the effectiveness of these modifications. We reviewed the surgical outcomes of 87 patients divided into the following three groups based on the surgical strategy used: group S (n = 49), periods of deep HCA with alpha-stat strategy; group M1 (n = 19), deep HCA with modifications of slower cooling and rewarming rates and the pH-stat strategy for cooling: and group M2 (n = 13), multiple short periods of moderate HCA. PEA provided significant improvement of pulmonary hemodynamics in each group. Sixteen (29%) of the 49 group S patients suffered NAEs, associated with total circulatory arrest time (cutoff, 57min) and Jamieson type I disease. The Group M1 and M2 patients did not suffer NAEs, although the group M1 patients had prolonged cardiopulmonary bypass (CPB) and more frequent respiratory failure. NAEs were common after PEA performed under periods of deep HCA. The modified surgical strategy could decrease the risk of NAEs but increase the risk of respiratory failure. Multiple short periods of moderate HCA may be useful for patients at risk of NAEs.

Moderate Hypothermic Circulatory Arrest Model in Rats: A New Model with Hyperkalemia-Induced Cardioplegia.

Moderate hypothermic circulatory arrest (MHCA) is a safe and effective method of cardiopulmonary bypass (CPB). However, most present rat models involve a deep hypothermic circulatory arrest, which cannot exactly reflect the clinical situation. The aim of this study was to establish a novel and safe rat model of MHCA with hyperkalemia-induced cardioplegia to study the pathophysiology of potential complications. Ten adult male Sprague-Dawley rats (age, 16-18 weeks; weight, 450-550 g) were used. The entire CPB circuit consisted of a reservoir, peristaltic pump, membrane oxygenator, heat exchanger, and hemoconcentrator, all of which were connected via silicon tubing. The prime solution was approximately 19 mL. The right jugular vein, right femoral artery, and left femoral artery were cannulated. Blood was drained from the right atrium through the right jugular vein and perfused to the rats via the left femoral artery. CPB was commenced at a full flow rate. The rats were cooled to a rectal temperature of 25°C, and cardioplegia was induced by systemic hyperkalemia. After that, MHCA was carried out for 30 min. At the same time, system self-ultrafiltration was carried out to decrease the concentration of potassium by a hemoconcentrator. The circulatory arrest was followed by reperfusion and over 30 min of rewarming. CPB carefully was terminated. Blood in the circuit slowly was centrifuged for autotransfusion. Blood gas and hemodynamic parameters were recorded at each time point before CPB, before MHCA, at 10 min after the initiation of rewarming, and after CPB. All CPB and MHCA procedures successfully were achieved. One rat died of respiratory failure. Cardioplegia with systemic hyperkalemia was induced by 1 mL of 10% potassium chloride injected into the reservoir, and the concentration of potassium was maintained at 17 ± 3 mmol/L. Cardiac function and blood pressure were stable after the operation. A novel and safe rat model of MHCA with hyperkalemia-induced cardioplegia successfully was established.

Intraoperative Fenestration of Frozen Elephant Trunk (FET) and Total Arch Replacement for Aortic Dissection in Aberrant Subclavian Artery.

Total arch replacement (TAR) and the frozen elephant trunk (FET) routinely are performed to treat aortic dissection. When aortic dissection combines with the aberrant right subclavian artery (aRSA), routine TAR+FET will occlude the ostium of aRSA. But there is no consensus regarding the optimal surgical strategy to revascularize the aRSA. We seek an uncomplicated and less time-intensive way to reconstruct the aRSA. From July 2020 to April 2022, six patients with aortic dissection and aRSA underwent TAR+FET and intraoperative fenestration on the descending trunk. The mean age of the patients was 51.7 (SD 16.2; range 30.0-72.0). TAR+FET was performed via a median sternotomy and under cardiopulmonary bypass (CPB) and moderate hypothermic circulatory arrest (HCA). A fenestra of descending trunk was made intraoperative. There was no operative death in hospital and follow up. The average aortic cross-clamp time, SACP time, and lower body circulatory arrest time was 138.8 (SD 22.5; range 103.0-156.0) min and 28.3 (SD 3.9; range 25.0-35.0) min. Bleeding, neurological deficit, visceral ischemia, injury to the spinal cord, or organ dysfunction was not observed. Follow-up CTA showed the blood flow of aRSA was patent in all patients. TAR+FET and intraoperative fenestration on the descending trunk is an efficacious approach. It also reduces the difficulty of reconstruction the aRSA in aortic dissection patients.

Safety of retrograde cerebral perfusion under moderate hypothermia for hemiarch replacement.

Aortic surgeries performed under moderate hypothermia require antegrade cerebral perfusion. The influence of retrograde cerebral perfusion under moderate hypothermic circulatory arrest remains unknown. To clarify this effect, this study aimed to compare the early outcomes of retrograde versus antegrade cerebral perfusion under moderate hypothermia for hemiarch replacement. Between March 2009 and April 2020, 391 hemiarch replacements under moderate hypothermic circulatory arrest via median sternotomy were performed at our institution. Of these, 70 involved retrograde perfusion and 162 involved antegrade perfusion. Propensity score matching was used to compare 61 pairs of retrograde and antegrade cases. Retrograde and antegrade strategy under moderate hypothermia resulted in comparable operative mortality (3.3% vs. 1.6%, P > 0.99), permanent neurological deficits (8.5% vs. 6.6%, P > 0.99), and temporary neurological deficits (24.6% vs. 39.3%, P = 0.33). Retrograde surgery was associated with shorter circulatory arrest times (31.4 ± 8.2min vs. 37.4 ± 12.2min, P = 0.005) and fewer red blood cell transfusions (4.6 ± 3.9 units vs. 8.2 ± 5.1 units, P < 0.001) than those with antegrade surgery. Retrograde cerebral perfusion under moderate hypothermia for hemiarch replacement yields excellent operative outcomes, equivalent to those achieved using an antegrade strategy.

Comparison of short-term outcomes of mild and moderate hypothermic circulatory arrest in aortic arch surgery: a single center retrospective cohort study.

BackgroundAortic arch surgery is one of the major challenges in modern aortic surgery, special cerebral and visceral organ protective strategies are still under progress. Whether mild hypothermic circulatory arrest (Mi-HCA) can be safely used in aortic arch surgery (AAS) is the focus of attention.MethodsFrom January 2017 to June 2021, a retrospective cohort study of 138 consecutive patients was conducted at Beijing Anzhen Hospital. The study comprised patients who underwent AAS performed by a single surgeon during moderate-to-mild HCA. According to the core temperature at the beginning of circulatory arrest, the patients were divided into three groups: T1 group (n=45; 25.76±0.75 ℃), T2 group (n=43; 28.79±0.81 ℃), T3 group (n=50; 31.46±0.79 ℃). Perioperative clinical data were analyzed to assess the differences between groups.ResultsIn this cohort, the average durations of the operation, cardiopulmonary bypass (CPB), cross-clamp, circulatory arrest, and selective antegrade cerebral perfusion (SACP) were 6.53±1.48 h, 184.07±56.69 min, 101.04±37.92 min, 23.01±9.86 min, and 27.18±11.52 min, respectively. We observed new postoperative permanent neurological dysfunction (PND) in 12 patients (8.7%) and transient neurological dysfunction in 18 patients (13.04%). The in-hospital mortality rate was 6.52% (n=9). The durations of the operation, CPB, cross-clamp, circulatory arrest, and SACP were significantly reduced in the Mi-HCA group (i.e., T3 group, P<0.001; P<0.001; P<0.001; P=0.002; P<0.001, respectively). The incidence of PND and major adverse events (MAEs) were significantly reduced among the three groups (P=0.025; P=0.035). Multivariate logistic regression analysis models showed that Mi-HCA was an independent protective factor in reducing postoperative MAEs [relative risk (RR) =0.12; 95% confidence interval (CI): 0.02–0.90; P=0.0385].ConclusionsThe short-term outcomes of Mi-HCA combined with SACP in AAS were acceptable. Similarly, the protection of distal organs and the spinal cord was observed compared to the MHCA strategy, and a lower incidence of MAEs was obtained. Current data suggest that the mild hypothermia strategy can be safely applied for AAS.

Prediction of Acute Kidney Injury by Cystatin C and [TIMP-2]*[IGFBP7] after Thoracic Aortic Surgery with Moderate Hypothermic Circulatory Arrest

(1) Background: Acute kidney injury (AKI) is a common complication following thoracic aortic surgery (TAS), with moderate hypothermic circulatory arrest (MHCA). However, prediction of AKI with classical tools remains uncertain. Therefore, it was the aim of the present study to evaluate the role of new biomarkers in patients after MHCA. (2) Methods: 101 consecutive patients were prospectively enrolled. Measurements of urinary [TIMP-2]*[IGFBP7] and Cystatin C in the blood were performed perioperatively. Primary endpoint was the occurrence of AKI stage 2 or 3 (KDIGO-classification) within 48 h after surgery (AKI group). (3) Results: Mean age of patients was 69.1 ± 10.9 years, 35 patients were female (34%), and 13 patients (13%) met the primary endpoint. Patients in the AKI group had a prolonged ICU-stay (6.9 ± 7.4 days vs. 2.5 ± 3.1 days, p < 0.001) as well as a higher 30-day-mortality (9/28 vs. 1/74, p < 0.001). Preoperative serum creatinine (169.73 ± 148.97 μmol/L vs. 89.74 ± 30.04 μmol/L, p = 0.027) as well as Cystatin C (2.41 ± 1.54 mg/L vs. 1.13 ± 0.35 mg/L, p = 0.029) were higher in these patients. [TIMP-2]*[IGFBP7] increased significantly four hours after surgery (0.6 ± 0.69 mg/L vs. 0.37 ± 0.56 mg/L, p = 0.03) in the AKI group. Preoperative Cystatin C (AUC 0.828, p < 0.001) and serum creatinine (AUC 0.686, p = 0.002) as well as [TIMP-2]*[IGFBP7] 4 h after surgery (AUC 0.724, p = 0.020) were able to predict postoperative AKI. The predictive capacity of Cystatin C was superior to serum creatinine (p = 0.0211) (4) Conclusion: Cystatin C represents a very sensitive and specific biomarker to predict AKI in patients undergoing thoracic surgery with MHCA even before surgery, whereas the predictive capacity of [TIMP-2]*[IGFBP7] is only moderate and inferior to that of serum creatinine.

Neuroprotective strategies with circulatory arrest in open aortic surgery - A meta-analysis.

ObjectiveDeep hypothermic circulatory arrest (DHCA) in aortic surgery is associated with morbidity and mortality despite evolving strategies. With the advent of antegrade cerebral perfusion (ACP), moderate hypothermic circulatory arrest (MHCA) was reported to have better outcomes than DHCA. There is no standardised guideline or consensus regarding the hypothermic strategies to be employed in open aortic surgery. Meta-analysis was performed comparing DHCA with MHCA + ACP in patients having aortic surgery.MethodsA systematic review of the literature was undertaken. Any studies with DHCA versus MHCA + ACP in aortic surgeries were selected according to specific inclusion criteria and analysed to generate summative data. Statistical analysis was performed using STATS Direct. The primary outcomes were hospital mortality and post-operative stroke. Secondary outcomes were cardiopulmonary bypass time (CPB), post-operative blood transfusion, length of ICU stay, respiratory complications, renal failure and length of hospital stay. Subgroup analysis of primary outcomes for Arch surgery alone was also performed.ResultsFifteen studies were included with a total of 5869 patients. There was significantly reduced mortality (Pooled OR = +0.64, 95% CI = +0.49 to +0.83; p = 0.0006) and stroke rate (Pooled OR = +0.62, 95% CI = +0.49 to +0.79; p < 0.001) in the MHCA group. MHCA was associated significantly with shorter CPB times, shorter duration in ICU, less pulmonary complications, and reduced rates of sepsis. There was no statistical difference between the two groups in terms of circulatory arrest times, X-Clamp times, total operation duration, transfusion requirements, renal failure and post-op hospital stay.ConclusionMHCA + ACP are associated with significantly better post-operative outcomes compared with DHCA for both mortality and stroke and majority of the secondary outcomes.

Moderate and Deep Hypothermic Circulatory Arrest Have Comparable Effects on Severe Systemic Inflammatory Response Syndrome After Total Aortic Arch Replacement in Patients With Type A Aortic Dissection

Background: The objective of this study was to compare the incidence of severe systemic inflammatory response syndrome (sSIRS) after total aortic arch replacement between patients who underwent moderate hypothermic circulatory arrest (MHCA) and those who underwent deep hypothermic circulatory arrest (DHCA).Methods: At Fuwai Hospital, 600 patients who underwent total aortic arch replacement with MHCA or DHCA from January 2013 to December 2016 were consecutively enrolled and divided into DHCA (14.1–20.0°C) and MHCA (20.1–28.0°C) groups. Preliminary statistical analysis revealed that some baseline indicators differed between the two groups; therefore, propensity score matching (PSM) was used to balance the covariates. Post-operative sSIRS as the primary outcome was compared between the groups both before and after PSM.Results: A total of 275 (45.8%) patients underwent MHCA, and 325 (54.2%) patients underwent DHCA. After PSM analysis, a total of 191 matched pairs were obtained. The overall incidence of sSIRS was 27.3%. There was no significant difference in post-operative sSIRS between the MHCA group and the DHCA group in either the overall cohort or the PSM cohort (no-PSM: P = 0.188; PSM: P = 0.416); however, post-operative sSIRS was increased by ~4% in the DHCA group compared with the MHCA group in both the no-PSM and PSM cohorts (no-PSM: 29.5 vs. 24.7%; PSM: 29.3 vs. 25.1%). Both before and after PSM, the rates of gastrointestinal hemorrhage and pulmonary infection and post-operative length of stay were significantly increased in the DHCA group compared with the MHCA group (P < 0.05), and the remaining secondary outcomes were not significantly different between the groups.Conclusions: MHCA and DHCA are associated with comparable incidences of sSIRS in patients following total aortic arch replacement for type A aortic dissection. However, the MHCA group had a shorter cardiopulmonary bypass time, a shorter post-operative length of stay and lower pulmonary infection and gastrointestinal hemorrhage rates than the DHCA group. We cautiously recommend the use of MHCA for most total arch replacements in patients with type A aortic dissection.