Safety of Moderate Hypothermia With Antegrade Cerebral Perfusion in Total Aortic Arch Replacement

Open, endovascular or hybrid repair of aortic arch disease: narrative review of diverse strategies with diverse options

OBJECTIVES

The management of aortic arch disease is complex. Open surgical management continues to evolve, and the introduction of endovascular repair is revolutionizing aortic arch surgery. Although these innovative techniques have generated the opportunity for better outcomes in select patients, they have also introduced confusion and uncertainty regarding best practices.

METHODS

In New York, we developed a collaborative group, the New York Aortic Consortium, as a means of cross-linking knowledge and working together to better understand and treat aortic disease. In our meeting in May 2023, regional aortic experts and invited international experts discussed the contemporary management of aortic arch disease, differences in interpretation of the available literature and the integration of endovascular technology into disease management. We summarized the current state of aortic arch surgery in this review article.

RESULTS

Approaches to aortic arch repair have evolved substantially, whether it be methods to reduce cerebral ischaemia, improve haemostasis, simplify future operations or expand options for high-risk patients with endovascular approaches. However, the transverse aortic arch remains challenging to repair. Among our collaborative group of cardiac/aortic surgeons, we discovered a wide disparity in our practice patterns and our management strategies of patients with aortic arch disease.

CONCLUSIONS

It is important to build unique institutional expertise in the context of complex and evolving management of aortic arch disease with open surgery, endovascular repair and hybrid approaches, tailored to the risk profiles and anatomical specifics of individual patients.

Hypothermic circulatory arrest at 20 ℃ does not deteriorate coagulopathy compared to 28 ℃ in a pig model

It is believed that a lower temperature setting of hypothermic circulatory arrest (HCA) in thoracic aortic surgery causes coagulopathy, resulting in excessive bleeding. However, experimental studies that eliminate clinical factors are lacking. The objective of this study is to investigate the influence of the temperature setting of HCA on coagulation in a pig model. Ten pigs were divided into the following two groups: moderate temperature at 28 °C (group M, n = 5) or lower temperature at 20 °C (group L, n = 5). Two hours of HCA during a total of 4 h of cardiopulmonary bypass (CPB) were performed. Blood samples were obtained at the beginning (T1) and the end (T2) of the surgery, and coagulation capability was analyzed through standard laboratory tests (SLTs) and rotational thromboelastometry (ROTEM). In SLTs, hemoglobin, fibrinogen, platelet count, prothrombin time, and activated partial thromboplastin time were analyzed. In ROTEM analyses, clotting time and clot formation time of EXTEM, maximum clot firmness (MCF), and maximum clot elasticity (MCE) of EXTEM and FIBTEM were analyzed. Fibrinogen decreased significantly in both groups (group M, p = 0.008; group L, p = 0.0175) at T2, and FIBTEM MCF and MCE also decreased at T2. There were no differences regarding changes in parameters of SLTs and ROTEM between groups. CPB decreases coagulation capacity, contributed by fibrinogen. However, a lower temperature setting of HCA at 20 °C for 2 h did not significantly affect coagulopathy compared to that of HCA at 28 °C after re-warming to 37 °C.

Relationship between perioperative cardiopulmonary bypass time, platelet count, fibrinogen level, rotational thromboelastometry data, antithrombin level, and blood loss volume and the effects of deep hypothermic circulatory arrest: An observational study

INTRODUCTION

We hypothesized that perioperative fibrinogen level, platelet count, and rotational thromboelastometry (ROTEM) data values decrease in proportion to cardiopulmonary bypass (CPB) time, particularly in patients who underwent deep hypothermic circulatory arrest (DHCA).

METHODS

A total of 160 patients were enrolled and divided into the following three groups depending on CPB time: <2-h, 2- 3-h, and >3-h groups. Blood samples were obtained during CPB weaning. Platelet count, ROTEM data, fibrinogen level, and antithrombin level were determined. For propensity matching, we selected 15 patients who underwent DHCA and 15 patients who did not undergo DHCA and used propensity scores to match CPB time and other characteristics.

RESULTS

The <2-h, 2-3-h, and >3-h groups included 74, 63, and 23 patients, respectively. No significant differences in platelet count and fibrinogen level were observed between the groups. Antithrombin level and amplitude of clot firmness at 10 min in the EXTEM and FIBTEM tests were lowest in the >3-h group. Similarly, blood loss volume and transfusion volume were highest in the >3-h group. Significant differences in platelet count, ROTEM data, lowest esophageal and bladder temperatures, and transfusion volume were observed between patients who underwent DHCA and patients who did not undergo DHCA.

CONCLUSIONS

The longer the CPB time, the greater the perioperative blood loss volume and transfusion volume, particularly if CPB time is greater than 3 hours. Sub-group analysis revealed that DHCA affects perioperative platelet count and function as well as blood loss volume.

Multicenter Comparison of Aortic Arch Aneurysms and Dissections Zone 0 Hybrid and Total Endovascular Repair

PURPOSE

Comparison of hybrid and total endovascular aortic arch repair at two tertiary vascular surgery centers.

MATERIALS AND METHODS

Consecutive patients undergoing hybrid (HG) or total endovascular (TEG) total aortic arch repair for aneurysms or dissections were included (2008-2022). Primary outcome measure was 30-day mortality. Secondary outcomes were major complications, technical success (defined as absence of surgical conversion/mortality, high-flow endoleaks or branch/limb occlusion), clinical success (defined as absence of disabling clinical sequelae), late and aortic-related mortality/reinterventions, freedom from endoleaks, aortic diameter growth > 5 mm, graft migration and supra-aortic trunks (SAT) patency.

RESULTS

In total, 30 patients were included, 17 in HG and 13 in TEG. TEG presented shorter intervention time (240.5 vs 341 min, p = 0.01), median ICU stay (1 vs 4.5 days, p < 0.01) and median length of stay (8 vs 17.5 days, p < 0.01). No intraoperative deaths occurred. Technical success was 100%; clinical success was 70.6% in HG and 100% in TEG (p = 0.05). Thirty-day mortality was 13.3%, exclusively in HG (p = 0.11). Nine major complications occurred in 8 patients, 5 in HG and 3 in TEG (p = 0.99), among which five strokes, two in HG and three in TEG (p = 0.62). Late mortality was 38.5%, six patients in HG and four in TEG, p = 0.6. Two late aortic-related deaths occurred in HG (p = 0.9). Two aortic-related reinterventions, no graft migration or SAT occlusion was observed.

CONCLUSIONS

Total endovascular repair seems to shorten operative times and provide higher clinical success compared with hybrid solutions, without significant 30-day mortality differences. The most common major complication is stroke.

Acute renal injury after aortic arch reconstruction with cardiopulmonary bypass for children: prediction models by machine learning of a retrospective cohort study

BACKGROUND

Acute renal injury (AKI) after aortic arch reconstruction with cardiopulmonary bypass leads to injury of multiple organs and increases perioperative mortality. The study was performed to explore risk factors for AKI. We aim to develop a prediction model that can be used to accurately predict AKI through machine learning (ML).

METHODS

A retrospective analysis was performed on 134 patients with aortic arch reconstruction with cardiopulmonary bypass who were treated at our hospital from January 2002 to January 2022. Risk factors for AKI were compositive and were evaluated with comprehensive analyses. Six artificial intelligence (AI) models were used for machine learning to build prediction models and to screen out the best model to predict AKI.

RESULTS

Weight, eGFR, cyanosis, PDA, newborn birth and duration of renal ischemia were closely related to AKI. By integrating the results of the training cohort and validation cohort, we finally confirmed that the logistic regression model was the most stable model among all the models, and the logistic regression model showed good discrimination, calibration and clinical practicability. Based on 6 independent factors, the dynamic nomogram can be used as a predictive tool for clinical application.

CONCLUSIONS

DHCA could be considered in aortic arch reconstruction if additional perfusion of lower body were not performed especially when renal ischemia is greater than 30 min. Machine Learning models should be developed for early recognition of AKI.

TRIAL REGISTRATION

ChiCTR, ChiCTR2200060552. Registered 4 june 2022.

Retrograde Cerebral Perfusion May Decrease Stroke Risk During Elective Aortic Arch Surgery

OBJECTIVE

Controversy remains regarding the optimal neuroprotection strategy for elective hemiarch replacement (HEMI). This study sought to compare outcomes in patients who underwent HEMI utilizing the 2 most common contemporary methods of cerebral protection.

METHODS

The ARCH international aortic database was queried, and 782 patients undergoing elective HEMI with circulatory arrest from 2007 to 2012 were identified. There were 418 patients who underwent HEMI using moderate hypothermia (nasopharyngeal temperature 20.1 to 28.0 °C) and antegrade cerebral perfusion (MHCA/ACP). There were 364 patients who underwent HEMI using deep hypothermia (nasopharyngeal temperature 14.1 to 20 °C) and retrograde cerebral perfusion (DHCA/RCP). Adverse outcomes were compared between the groups using both univariable and multivariable analyses.

RESULTS

Patients who underwent MHCA/ACP were older (64 vs 61 years, P = 0.01) and more frequently had peripheral vascular disease than DHCA/RCP patients (28.5% vs 7.1%, P < 0.001). Patients in the DHCA/RCP group had a greater incidence of full aortic root replacement (55.8% vs 26.4%, P < 0.001) and more frequently had a central cannulation strategy (83% vs 55.7%, P < 0.001). Cardiopulmonary bypass (170 vs 157 min, P = 0.002) and aortic cross-clamp (134 vs 92 min, P < 0.001) times were significantly longer in the DHCA/RCP group. On univariable analysis, overall mortality was statistically similar between groups (MHCA/ACP 3.4% vs DHCA/RCP 2.3%, P = 0.47), but permanent neurologic deficits were significantly lower in the DHCA/RCP cohort (MHCA/ACP 3.9% vs DHCA/RCP 1.0%, P = 0.02). Multivariable analysis showed no difference in mortality nor perioperative stroke between perfusion cohorts.

CONCLUSIONS

Both MHCA/ACP and DHCA/RCP are excellent neuroprotective strategies that produce low mortality in patients undergoing elective HEMI. DHCA/RCP may demonstrate theoretically improved neurologic outcomes compared with MHCA/ACP, but this topic warrants further study.

Systematic review and network meta-analysis of various nadir temperature strategies for hypothermic circulatory arrest for aortic arch surgery

BACKGROUND

The optimal nadir temperature for hypothermic circulatory arrest during aortic arch surgery remains unclear. We aimed to assess and compare clinical outcomes of all three temperature strategies (deep, moderate, and mild hypothermia) using a network meta-analysis.

METHODS

After literature search with MEDLINE and EMBASE through December 2021, studies comparing clinical outcomes with deep (<20°C), moderate (20-28°C), or mild (>28°C) hypothermic circulatory arrest were included. The outcomes of interest were perioperative mortality, stroke, transient ischemia attack (TIA), acute kidney injury (AKI), postoperative bleeding, operative time, and length of hospital stay.

RESULTS

Twenty-four comparative studies were identified, including 6018 patients undergoing aortic arch surgery using hypothermic circulatory arrest (deep: 2,978, moderate: 2,525, and mild: 515). Compared to deep hypothermia, mild and moderate hypothermia were associated with lower mortality (mild vs. deep: odds ratio [OR] 0.50; 95% confidence interval (CI) 0.29-0.87, moderate vs. deep: OR 0.68; 95% CI 0.54-0.86). In addition, mild hypothermia was associated with lower stroke (OR 0.50; 95% CI 0.28-0.89), AKI (OR 0.36; 95% CI 0.15-0.88) and postoperative bleeding (OR 0.55; 95% CI 0.31-0.97) compared to deep hypothermia. There was no significant difference between mild and moderate hypothermia in mortality, AKI or bleeding occurrence, while mild hypothermia was associated with shorter operative time and hospital stay. There was no significant difference in TIA rate among three groups.

CONCLUSIONS

Mild hypothermia was associated with overall more favorable clinical outcomes with comparable neurological complications compared to deep hypothermia. Furthermore, considering the shorter operative time and hospital stay compared with moderate hypothermia, mild hypothermia may be warranted when appropriate adjunctive cerebral perfusion is employed.

Prolonged Periods of Antegrade Cerebral Perfusion Are Safe During Elective Arch Surgery

BACKGROUND

Cerebral circulatory arrest times >40 minutes during aortic surgery have previously been shown to be associated with increased morbidity and mortality. The purpose of this study was to redefine what would constitute a safe period of circulatory arrest for patients who underwent elective proximal aortic operations requiring antegrade cerebral perfusion (ACP).

METHODS

The ARCH International aortic database was queried, and 2008 patients undergoing elective arch operations with circulatory arrest using ACP were identified. Circulatory arrest time was categorized a priori in 10-minute intervals. To further determine the impact of this variable on outcomes, hierarchical multivariable regression analysis was performed.

RESULTS

Unadjusted mortality increased with increasing circulatory arrest time from 4.8% (<40 minutes) to 13.5% (>90 minutes; P < .001), but risk of stroke was not impacted (P = .4). When treated as a continuous variable, mortality increased significantly with increasing circulatory arrest time, whereas the risk of permanent stroke did not. Using <40 minutes as the reference, multivariable analysis showed no statistical increase in mortality for ranges up to 80 minutes of circulatory arrest. The risk of permanent stroke was not significantly higher for any time interval >40 minutes up to 90 minutes.

CONCLUSIONS

In this series of patients who underwent elective proximal aortic surgery using ACP, periods of circulatory arrest up to at least 80 minutes were not associated with significant increases in mortality or permanent stroke. Modern perfusion strategies have allowed for increased safety during elective arch cases requiring prolonged periods of circulatory arrest.

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

OBJECTIVES

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.

METHODS

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).

RESULTS

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, p value = .0029 and OR, 1.74, 95% CI, 1.09-2.77, p value = .019).

CONCLUSIONS

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.

Rapid cooling is a safe technique in patients undergoing circulatory arrest for aortic repair

Objective

To evaluate our institutional experience with rapid cooling for hypothermic circulatory arrest in proximal aortic repair.

Methods

We retrospectively reviewed data from 2171 patients who underwent proximal aortic surgery requiring hypothermic circulatory arrest between 1991 and 2020. Cooling times were divided into quartiles and clinical outcome event rates were compared across quartiles using contingency table methods. Incremental effect of cooling time was assessed in the context of other perfusion time variables using multiple logistic regression analysis.

Results

Median age was 61 years (interquartile range, 49-70 years) and 34.1% of patients were women. The procedure was emergent in 33.5% of patients, 22.9% had a previous sternotomy. The median circulatory arrest time was 22 minutes, with retrograde cerebral perfusion used in 94% of cases. Median cardiopulmonary bypass time was 149 minutes, with an aortic crossclamp time of 90 minutes. Patients were cooled to deep hypothermia. The first quartile had cooling times ranging from 5 to 13 minutes, second 14 to 18 minutes, third 19-23 minutes, and fourth 24-81 minutes. Overall, 30-day mortality was 9.4%, and was not significantly different across quartiles. There was a statistically significant trend toward lower rates of postoperative encephalopathy, gastrointestinal complications, and respiratory failure with shorter cooling times (P < .001, .006, and < .001, respectively). There was no significant difference in rates of postoperative stroke or dialysis.

Conclusions

Rapid cooling can be performed safely in patients undergoing aortic surgery requiring circulatory arrest without increasing mortality or stroke. There were significantly lower rates of coagulopathy, respiratory failure, and postoperative encephalopathy with shorter cooling times.

Endovascular surgery for thoracic aortic pathologies involving the aortic arch

Background

Aortic arch pathologies are serious clinical conditions associated with a very dismal prognosis. Traditional open surgery has a high mortality and is not suitable for critically ill patients. Recently years, endovascular treatment of thoracic aorta has made rapid progress and has been gradually applied to the treatment of aortic arch pathologies. However, maintaining cerebral blood flow during endovascular treatment of aortic arch lesions remains a challenge at this time. This study aims to evaluate the feasibility, efficacy, and safety of endovascular treatment of thoracic aortic pathologies involving the aortic arch, and to present initial experience with this technique.

Methods

From October 2016 to December 2020, patients who met the inclusion criteria were enrolled. All patients underwent thoracic endovascular aortic repair with the proximal landing zone of the stent-graft in the aortic arch at Ishimaru zones 0–1, in which cerebral flow needs to be maintained during surgery, and the supra-aortic branches were reconstruction with either in situ fenestration or the chimney technique.

Results

A total of 62 cases with lesions involving the arch were treated with endovascular surgery. Total supra-aortic branches reconstruction was successfully performed in 51 cases, the left carotid artery (LCA) and the innominate artery reconstruction were performed in eight cases, the left subclavian artery (LSA) and the LCA were reconstructed in three patients. Among them, the in situ fenestration or chimney repair technique for the LSA was successful performed in 42 and 12 cases. However, in 20 patients, attempts to reconstruction the LSA using the fenestration technique were unsuccessful due to tortuous and angulated vessels. Early mortality was 6.45%. No neurological complications related to surgery occurred. Computer tomography images at post-operative follow-up (mean 3.51 months) confirmed patency of all branch stents without any signs of endoleaks, migration, conversion to retrograde dissection or receive open-heart surgery.

Conclusion

The endovascular technique is an effective, feasible, safe and repeatable method to reconstruct the aortic arch, which allows for the reconstruction of the supra-aortic branches.

Early and Midterm Outcomes of Type II Hybrid Arch Repair for Complex Aortic Arch Pathology

Background

The hybrid arch repair (HAR) is an appealing surgical option in the management of aortic arch diseases. The aim is to evaluate the short and mid-term outcomes of type II HAR involving replacement of the ascending aorta, arch debranching, and zone 0 stent graft deployment in diverse arch pathologies.

Methods

200 patients with various diffuse aortic pathologies involving the arch were enrolled between 2016 and 2019. Complex arch diseases included acute type A dissection (n = 129, 64.5%), acute type B dissection (n = 16, 8.0%), aortic arch aneurysm (n = 42, 21.0%) and penetrating arch ulcer (n = 13, 6.5%). Mortality, morbidity, survival and re-intervention were analyzed.

Results

The overall 30-day mortality rate was 8.0% (16/200). Stroke was present in 3.5% (7/200) of the general cohort and spinal cord injury was occurred in 3.0% (6/200). Multivariable logistic analysis showed that cardiac malperfusion and CPB time were the risk factors associated with 30-day mortality. The mean follow-up duration was 25.9 months (range 1–57.2 months), and the 3-year survival rate was 83.1%. On Cox regression analysis, age, diabetes, cardiac malperfusion and CPB time predicted short and mid-term overall mortality. A total of 3 patients required reintervention during the follow-up due to the thrombosis of epiaortic artificial vessels (n = 1), anastomotic leak at the site of the proximal ascending aorta (n = 1) and the type I endoleak (n = 1).

Conclusions

Type II HAR was performed with satisfactory early and mid-term outcomes in complex aortic arch pathologies.

Duration of deep hypothermic circulatory arrest for aortic arch surgery: is it a myth, fiction, or scientific leap?

INTRODUCTION

The use of deep hypothermic circulatory arrest (DHCA) to provide aortic surgeons with a bloodless operative field while simultaneously protecting the brain and peripheries from ischemic damage revolutionized cardiac and aortic surgery, and is currently used in specialist centers across the globe. However, it is associated with manifold adverse outcomes, including neurocognitive dysfunction and mortality. This review seeks to analyze the relationship between DHCA duration and clinical outcome, and evaluate the controversies and limitations surrounding its use.

EVIDENCE ACQUISITION

We performed a review of available literature with statistical analysis to evaluate the relationship between DHCA duration (<40 min and >40 min) and key clinical outcomes, including mortality, permanent and temporary neurological deficit, renal damage, admission length, and reintervention rate. The controversies surrounding DHCA use and future directions for care are also explored.

EVIDENCE SYNTHESIS

Statistical analysis revealed no significant association (P>0.05) between DHCA duration and clinical outcomes (early and late mortality rates, neurological deficit, admission length, and reintervention rate), both with and without adjunctive perfusion techniques.

CONCLUSIONS

Available literature suggests that the relationships between DHCA duration (with and without adjunctive perfusion) and clinical outcomes are unclear, and at present not statistically significant. Alternative surgical and endovascular techniques have been identified as promising novel approaches not requiring DHCA, as have the use of biomarkers to enable early diagnosis and intervention for aortic pathologies.

Recombinant Activated Factor VII in Aortic Surgery for Patients Under Hypothermic Circulatory Arrest

Purpose

We aimed to identify the risk factors of critical bleeding and investigate the safety of recombinant activated factor VII (rFVIIa) in aortic surgery under hypothermic circulatory arrest (HCA).

Patients and Methods

The present single-center retrospective study compared the baseline characteristics of 144 patients who underwent aortic surgery under HCA at our institute. Among the total cohort of 144 patients, 42 received rFVIIa (rFVIIa group), while the remaining 102 patients did not (non-rFVIIa group). Perioperative bleeding and transfusions, postoperative 30-day mortality, and adverse events (AEs) were analyzed in 29 propensity score-matched pairs.

Results

Before surgery, the rFVIIa group demonstrated a greater number of shocks (p=0.019), higher JapanSCORE II mortality rate (p=0.033), low platelet count (p=0.015) and fibrinogen (p<0.001) level, prolonged activated partial thromboplastin time (aPTT) (p=0.005) and prothrombin time international normalized ratio (PT-INR) (p=0.006), and longer aortic cross clamp time (p=0.049). Postoperative bleeding, transfusion, 30-day mortality, and AEs were comparable between the groups both in the entire-unmatched cohort and propensity score matching cohort.

Conclusion

Preoperative shock, higher JapanSCORE II mortality rates, low platelet and fibrinogen levels, prolonged aPTT and PT-INR, and longer aortic clamping time might be risk factors for excessive bleeding and indicate the need for rFVIIa treatment. The present study suggests that rFVIIa can be safely used to address critical and continuous bleeding in spite of adequate transfusion and supplementation of other coagulation factors in aortic surgery under HCA, without an increase in 30-day mortality and AEs.

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

Objective

Deep 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.

Methods

A 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.

Results

Fifteen 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.

Conclusion

MHCA + 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.

Rotational Thromboelastometry-Guided Transfusion Protocol to Reduce Allogeneic Blood Transfusion in Proximal Aortic Surgery With Deep Hypothermic Circulatory Arrest

OBJECTIVES

To determine the impact of a rotational thromboelastometry (ROTEM)-guided transfusion protocol on the use of blood products, patient outcomes, coagulation factor concentrates, and costs.

DESIGN

A single-center retrospective cohort study.

SETTING

A tertiary university hospital.

PATIENTS

Adults undergoing proximal aortic surgery with deep hypothermic circulatory arrest.

INTERVENTION

ROTEM-guided transfusion protocol compared with clinically-guided transfusion.

MEASUREMENTS AND MAIN RESULTS

Two hundred seventeen patients were included; seventy-one elective and 24 emergency patients in the clinically-guided group, and 59 elective and 63 emergency patients in the ROTEM-guided transfusion protocol group. In the ROTEM-guided transfusion protocol group, a significant reduction in transfusion of red blood cells (5 [3-8] v 2 [0-4], p < 0.001), platelet concentrate (2 [2-3] v 1 [1-2], p < 0.001), and plasma (1,980 mL [1,320-3,300] v 800 mL [0-1,000], p < 0.001) was seen in elective surgery. Emergency patients received fewer red blood cells (7 [5-10] v 5 [2-10], p = 0.040), platelet concentrate (3 [2-4] v 2 [2-3], p = 0.023), and plasma (3,140 mL [1,980-3,960] v 1,000 mL [0-1,400], p < 0.001). Prothrombin complex concentrate and fibrinogen concentrate were increased significantly in elective and emergency patients. The surgical reexploration for bleeding rate was decreased in elective patients 33.8% v 5.1%.

CONCLUSION

The implementation of a ROTEM-guided transfusion protocol might have the potential to decrease blood product transfusion and may improve patient outcomes.

Early outcome and mid-term survival after open arch repair using selective antegrade cerebral perfusion

OBJECTIVES

The introduction of selective antegrade cerebral perfusion technique as method of cerebral protection improved the outcome of open arch surgery. The aim of this study was to report early outcomes using this technique.

METHODS

Between 1997 and 2017, data were collected retrospectively for all patients who underwent surgical replacement of the aortic arch using selective antegrade cerebral perfusion (n = 938). To confirm the effectiveness of this cerebral protection method, early outcome and results were evaluated.

RESULTS

The incidence of postoperative permanent neurological dysfunction was 6.4%. Overall hospital mortality was 11.9% (n = 112). On multivariable analysis, age >75 years, female gender, euroscore at increment of 1 point, chronic renal failure, extension of thoracic aorta replacement and CPB time emerged as independent risk factors for hospital mortality. The mid-term survival at 1, 5, 10 and 15 years was 92%, 78%, 60% and 49%, respectively. The competing risk analysis for permanent neurological dysfunction and aortic reoperations was performed excluding the patients who died during the hospital stay. The cumulative incidence of permanent neurological dysfunction and aortic reoperations was 2% at 3 years, 3% at 5 years, 6% at 10 years, 12% at 3 years, 15% at 5 years and 19% at 10 years, respectively.

CONCLUSIONS

From the early 90s to the present day, the selective antegrade cerebral perfusion has confirmed to be a useful and "safe" method of brain protection in aortic arch surgery in terms of postoperative neurological complications.

Early and long-term results of hypothermic circulatory arrest in aortic surgery: a 20-year single-centre experience

AIMS

The aim of this study was to document the postoperative outcomes of patients who underwent hypothermic circulatory arrest (HCA), the evolution of HCA management over time and to identify the risks factor for early mortality and postoperative stroke.

METHODS

Four hundred and twenty-four patients who underwent aortic surgery with HCA at our institution between January 1995 and June 2016 were consecutively included.

RESULTS

The main indications were degenerative aneurysm (254; 59.9%) and acute type A aortic dissection (146; 34.4%). Interventions were performed under deep (18.4 ± 0.9°C; n = 350; 82.5%) or moderate (23.9 ± 1.9°C; n = 74; 17.5%) hypothermia. Antegrade cerebral perfusion (ACP) was employed in 86 (20.3%) cases. The use of moderate hypothermia significantly increased from 2011, to become the preferred strategy in 2016. The in-hospital mortality was 12.5% and the postoperative stroke rate was 7.1%. Kaplan--Meier 5-year survival was 65.7%. Nonelective timing [odds ratio (OR) 4.05; P < 0.001], stroke (OR 3.77' P = 0.032), renal failure (OR 2.49; P = 0.023), redo surgery (2.42; P = 0.049) and CPB time (OR 1.05; P = 0.03) were independent risk factors for in-hospital mortality in multivariate analysis. Femoral cannulation was the only independent risk factor for stroke (OR 3.97; P = 0.002). The level of hypothermia and the use of ACP were not associated with either in-hospital mortality or postoperative stroke.

CONCLUSION

HCA might be widely considered to achieve a radical treatment of the aortic disease, provided that hypothermia is maintained below the 24°C safety threshold and ACP is used for HCA exceeding 30 min, to ensure optimal brain, spinal cord and visceral organs protection.

Early-to-midterm outcomes of aortic balloon occlusion technique versus hybrid procedure for aortic arch diseases

OBJECTIVES

The goal of this study was to compare the early-to-midterm outcomes of patients treated with the frozen elephant trunk procedure with aortic balloon occlusion (FET-ABO) versus hybrid repair for aortic arch diseases.

METHODS

Patients who underwent the FET-ABO (n = 134) and the hybrid procedure (n = 220) from 2017 to 2020 at our institution were analysed retrospectively. Early-to-midterm outcomes were compared using inverse probability weighting. Low-risk and high-risk subgroup analyses were performed according to the cut-off of the additive European System for Cardiac Operative Evaluation value of 6.

RESULTS

The present study demonstrated similar 30-day mortality (3.7% vs 8.6%; P = 0.118) and adverse events between the FET-ABO and the hybrid groups. Fewer intraoperative red blood cell transfusions (0.54 ± 1.45 vs 1.26 ± 2.47 U; P = 0.001), decreased total hospital costs (P < 0.001) and considerable early-to-midterm survival [crude: hazard ratio (HR) 0.40, 95% confidence interval (CI) 0.17-0.91; P = 0.030; adjusted: HR 0.35, 95% CI 0.13-0.91; P = 0.032) were obtained with the FET-ABO compared to the hybrid procedure. The inverse probability weighting method substantiated the foregoing results. Adjusted subgroup analyses suggested that the FET-ABO procedure had a trend towards improved survival in low-risk patients (HR 0.17, 95% CI 0.03-0.93; P = 0.041) and achieved outcomes comparable to those of the hybrid procedure in high-risk patients (HR 0.46, 95% CI 0.15-1.42; P = 0.176).

CONCLUSIONS

The FET-ABO technique could be better promoted in hospitals lacking experience and equipment and could be more viable and cost-effective for selected patients compared with the hybrid procedure.

Optimal Degree of Hypothermia in Total Arch Replacement for Type A Aortic Dissection

Background: We sought to investigate the best degree of hypothermic cardiac arrest (HCA) in type A aortic dissection (TAAD) with a cohort of 1,018 cases receiving total arch replacement from 2013 to 2018 in Fuwai Hospital.

Method: The cohort was divided by DHCA (≤24°C, n = 580) vs. MHCA (>24°C, n = 438), and interquartile range (Q1–Q4). Primary endpoints included mortality, stroke, paraplegia, and continuous renal replacement therapy (CRRT), which were summarized as composite major outcomes (CMO).

Results: The Odds Ratio (OR) of CMO for MHCA was 0.7 (95% CI: 0.5–1.0, p = 0.06) (unadjusted) and 0.6 (95% CI: 0.4–1.0, p = 0.055) (adjusted). DHCA group tended to have a significantly longer CPB time (175.6 ± 45.6 vs. 166.8 ± 49.8 min, p = 0.003), longer hospital stay (16.0 ± 13.6 vs. 13.5 ± 6.8 days, p < 0.001), and ICU stay [5.0 (3.9–6.6) vs. 3.8 (2.0–5.6) days]. A significantly greater blood loss was observed in DHCA group, with a greater requirement for RBC and platelet transfusion. Of note, MHCA showed a significant protective effect (60% risk reduction) for older patients (above 60 years) (OR 0.4; 95% CI: 0.2–0.8; p = 0.009). By quartering, Q1 had significantly higher mortality (10.9%) than Q4 (5.2%) (p = 0.035). For other comparisons, the gap was significantly widened in quartering between Q1 and Q4, i.e., the lower the temperature, the worse the outcomes, and vice versa. Propensity score matching and sensitivity analyses confirmed the above findings.

Conclusions: A paradigm change from DHCA to MHCA may be encouraged in TAAD arch operation, especially for the elderly.

Early outcomes of hybrid type II arch repair versus total arch replacement with frozen elephant trunk in acute DeBakey type I aortic dissection: a propensity score-matched analysis

OBJECTIVES

The aim was to evaluate the short-term outcomes of hybrid type II arch repair (HAR) and total arch replacement with frozen elephant trunk (TAR with FET) for acute DeBakey type I aortic dissection patients.

METHODS

From January 2017 to June 2019, the clinical data of acute DeBakey type I aortic dissection patients in a single centre were retrospectively reviewed; there were 92 cases of HAR and 268 cases of TAR with FET, with 56 pairs by propensity score matching.

RESULTS

After matching, the composite end points including 30-day mortality, stroke, paraplegia, renal failure, hepatic failure, reintubation or tracheotomy and low cardiac output syndrome were comparable (21.4%, 12/56 in the HAR group vs 21.4%, 12/56 in the TAR with FET group, P = 1.000). The rate of acute kidney injury (AKI) was significantly lower in the HAR group (58.9%, 33/56 vs 80.4%, 45/56, P = 0.031). The distribution of AKI stage according to the Kidney Disease Improving Global Outcomes criteria was different (P = 0.039), with more patients suffering from high-grade AKI in the TAR with FET group. Multivariable logistic analysis showed that the procedure type (HAR or TAR with FET) was not an independent predictor of composite adverse events or stroke. HAR was identified as a protective factor against AKI (odds ratio 0.485, 95% confidence interval 0.287-0.822; P = 0.007).

CONCLUSIONS

In the treatment of acute DeBakey type I aortic dissection, no significant differences were found in early outcomes between the 2 groups, but HAR was associated with a significantly lower incidence of AKI.

Proximalized Total Arch Replacement Can Be Safely Performed by Trainee

BACKGROUND

The aim of the present study was to validate safety of total arch replacement (TAR) using a novel frozen elephant trunk device, operated by trainees as surgical education.

METHODS

Sixty-four patients including 19 patients (29.6%) with acute aortic dissection type A (AADA) underwent TAR in our institute between April 2014 and March 2019 were retrospectively analyzed. Twenty-nine patients were operated by trainees (group T) and 35 patients were operated by attending surgeons (group A).

RESULTS

Patient characteristics did not differ between groups. Operative time (409.4 ± 87.8 vs. 468.6 ± 129.6 minutes, p = 0.034), cardiopulmonary bypass time (177.7 ± 50.4 vs. 222.9 ± 596.7 minutes, p = 0.019), and hypothermic circulatory arrest time (39.5 ± 13.4 vs. 54.5 ± 18.5 minutes, p = 0.001) were significantly shorter in group A than in group T, but aortic clamping time did not differ between groups (115.3 ± 55.7 vs. 114.2 ± 35.0 minutes, p = 0.924) because the rate of concomitant surgery was higher in group A (37.1 vs. 10.3%, p = 0.014). Thirty-day mortality was 3.1% in the entire cohort. Although operation time was longer in group T, there were no significant difference in postoperative results between the groups, and the experience levels of the main operator were not independent predictors for in-hospital mortality + major postoperative complications. There was no difference in late death and aortic events between groups.

CONCLUSIONS

The present study demonstrated that TAR can be safely performed by trainees, and suggests TAR as a possible and safe educational operation.

Renal protective effect of the aortic balloon occlusion technique in total arch replacement with frozen elephant trunk

Background

Organ dysfunction caused by hypothermic circulatory arrest continues to concern surgeons. The aortic balloon occlusion (ABO) technique can significantly shorten the circulatory arrest time in total arch replacement with frozen elephant trunk (TAR with FET). This study aims to analyze the renal protective effect of the ABO technique and to analyze the predictors of acute kidney injury (AKI) and continuous renal replacement therapy (CRRT) after TAR with FET.

Methods

Between August 2017 and September 2018, 247 patients who underwent TAR with FET were divided into ABO and moderate hypothermic circulatory arrest (MHCA) groups. The primary endpoint was postoperative AKI defined by the Kidney Disease Improving Global Outcomes (KDIGO) criteria. Multivariable logistic analysis was used to identify the predictors of AKI and CRRT after TAR with FET.

Results

With the application of the ABO technique, the circulatory arrest time was significantly shortened (ABO 4, IQR: 3-6 vs. MHCA 18, IQR: 16-20, P<0.001). Meanwhile, surgeons safely set the lowest nasopharyngeal temperature at a higher grade (ABO 28.1, IQR: 27.4-28.5 vs. MHCA 24.7, IQR: 24.1-25.1, P<0.001). The peak serum creatinine (SCr) values within 48 hours after the surgery was lower in the ABO group than in the MHCA group (ABO 124, IQR: 97-173 vs. MHCA 146, IQR: 108-221, P=0.008). The distribution of AKI grade according to the KDIGO criteria differed between the two groups (P=0.04): more patients in the ABO group were free from AKI (Grade 0) than patients in the MHCA group (33% vs. 23.1%), and the proportion of patients with high-grade AKI (Grades 2 and 3) in the ABO group was lower than that in the MHCA group (21% vs. 32%). The ABO technique was associated with reduced potential for AKI, but was not protective for CRRT.

Conclusions

The ABO technique significantly shortened the circulatory arrest time and safely elevated temperature, and provided better renal protection in patients undergoing TAR with FET. The ABO technique did not reverse the need for CRRT, nor did it reduce mortality or major adverse events.

Long-term stroke incidence in proximal thoracic aorta aneurysm survivors

BACKGROUND

Aneurysm of proximal thoracic aorta (pTAA) is an often indolent, yet fatal disease. Although advancements in aneurysmal repair techniques have increased long-term survival rates, studies have proven that there are increases in perioperative risk for stroke incidence after pTAA surgery. Conversely, there is little evidence regarding the long-term stroke incidence in pTAA individuals, which strongly influences the morbidity, mortality, and usage of antithrombotic agents.

METHODS

Using the Taiwan National Health Insurance Research Database, a nationwide population-based cohort, we recruited 3013 pTAA survivors hospitalized from 1 January 2000 to 31 December 2012. To ensure study cohort quality, only patients aged 20 years and above who underwent aneurysmal repair surgery are included. The control cohort is identified by matching background features (comorbidities, age, gender) at a 1:4 ratio through the use of frequency matching. The primary outcomes include incidence of ischemic stroke and intracranial hemorrhage one month after aneurysmal repair surgery.

RESULTS

The mortality of pTAA survivors is nearly twice of the matched controls despite aneurysmal repair (28.5 % vs. 15.2%, p < 0.001). Long-term follow-up of participants indicated that pTAA survivors had a higher risk for hemorrhage stroke (adjusted hazard ratio (aHR): 1.93; 95% confidence interval (CI): 1.47-2.53), but no significant increase in risk for ischemic stroke (aHR: 1.07; 95% CI: 0.92-1.25). Hemorrhagic stroke occurrence was found to be associated with age and diabetes mellitus. Comparison on hemorrhagic stroke subtypes between study and matched cohorts showed no statistical differences in intracerebral hemorrhage and subarachnoid hemorrhage.

CONCLUSIONS

Despite the advancement of aneurysmal repair surgery, this study suggests that pTAA patients may still face an increased risk of hemorrhage stroke. Further investigation is warranted to provide better long-term care for the pTAA population.

Moderate Hypothermic Circulatory Arrest Is Preferable During Cardiopulmonary Bypass

The effect of temperature on cerebral injury during hypothermic circulatory arrest (HCA) has never been specifically studied. This study aimed to compare the effects of two different temperatures used for HCA on the degree of brain injury in pig models. Thirteen pigs were randomly assigned to a deep hypothermic circulatory arrest (DHCA) group (n = 5), moderate hypothermic circulatory arrest (MHCA) group (n = 5), or control group (n = 3). No significant differences in immunohistochemical assay results, including Bax, Bcl-2, and Caspase 3 staining, and a TUNEL assay, were observed between the DHCA and MHCA groups. Furthermore, no significant difference was found for biomarkers of brain injury (Soluble protein-100B) between the two experimental groups. Similarly, no significant difference was observed in the trend of changes in inflammatory factors, including tumor necrosis factor-α, interleukin (IL)-2, and IL-6, between the two groups (p > 0.05). However, coagulation factors, including FXI and FVII, were different between the DHCA and MHCA groups (p < 0.05). Therefore, it can be concluded that MHCA does not increase the risk of cerebral injury. Considering the adverse effects of DHCA on the coagulation system, MHCA is more suitable for current clinical practice.

Total Arch Replacement with Hypothermic Circulatory Arrest, Antegrade Cerebral Perfusion and the Y-graft

This study examines postoperative morbidity and mortality and long-term survival after total arch replacement (TAR) using deep to moderate hypothermic circulatory arrest (HCA), antegrade cerebral perfusion (ACP), and the Y-graft. Seventy-five patients underwent TAR with the Y graft. Deep to moderate HCA was initiated at 18-22°C. ACP was either initiated immediately (early ACP) or after the distal anastomosis was performed (late ACP). The arch vessels were then serially anastomosed to the individual limbs of the Y-graft. The median age was 66 years (range = 32-82). Etiology of aneurysmal dilatation included 20 (27%) patients with medial degenerations, 25 (33%) with chronic dissections, 14 (19%) with acute dissections, 9 (12%) with atherosclerosis and 2 (3%) with Marfan syndrome. In-hospital mortality was 5%. Neurologic complications occurred in 8 (11%) patients; 2 (3%) had strokes and 6 (8%) had transient neurologic deficits. Patients undergoing TAR with moderate hypothermia had a significantly higher incidence of new-onset renal insufficiency (3 [23%] vs [0%], P < 0.001) and TND (3 (23%) vs 3 (5%), P = 0.028) than the profound and deep hypothermia cohort. Excluding the 1 patient who died intraoperatively, 89% (95%CI: 79-94%) were alive at 1 year, 78% at 5 years (95%CI: 66-86%), and 73% at 10 years (95%CI: 59-82%). The combination of deep to moderate HCA, ACP, and the Y-graft is a safe and reproducible technique. Further inquiry is needed to assess if early ACP provides superior clinical outcomes.

The strategy of cardiopulmonary bypass for total aortic arch replacement and the frozen elephant trunk technique with aortic balloon occlusion

Objective

To investigate the use of the aortic balloon occlusion technique to assist total aortic arch replacement (TAR) with frozen elephant trunk (FET) to shorten the lower body circulatory arrest (CA) time and raise the nadir temperature during cardiopulmonary bypass.

Methods

This retrospective study reviewed consecutive patients that underwent aortic balloon occlusion to assist TAR with FET and patients that received conventional TAR with FET procedures. Preoperative characteristics, perioperative characteristics and postoperative outcomes were compared between the two groups.

Results

The study included130 patients treated with aortic balloon occlusion and 230 patients treated with conventional TAR with FET. The 30-day mortality rate was similar between the aortic balloon occlusion and conventional groups (4.62% versus 7.83%, respectively). Multivariate analysis showed that aortic balloon occlusion reduced the incidence of acute kidney injury, hepatic injury and red blood cell transfusion. The application of aortic balloon occlusion reduced the mean ± SD CA time from 17.24 ± 4.36 min to 6.33 ± 5.74 min, with the target nadir nasal temperature being increased from 25°C to 28°C.

Conclusion

The aortic balloon occlusion technique achieved significant improvements in reducing complications, but this did not translate into lower 30-day mortality.

Moderate and deep hypothermic circulatory arrest has a comparable effect on acute kidney injury after total arch replacement with frozen elephant trunk procedure in type A aortic dissection

OBJECTIVES

The goal was to investigate the prevalence of acute kidney injury (AKI) after total arch replacement with frozen elephant trunk procedure, which was achieved by antegrade cerebral perfusion and moderate hypothermic circulatory arrest (MHCA) or deep hypothermic circulatory arrest (DHCA) among patients with type A aortic dissection.

METHODS

Overall, 627 adult type A aortic dissection patients who underwent total arch replacement with frozen elephant trunk from January 2013 until December 2016 at Fuwai Hospital were divided into the DHCA (14.1-20.0°C) and MHCA (20.1-28.0°C) groups. Postoperative AKI as the primary outcome was compared using propensity-matched scoring.

RESULTS

Overall, 340 (54.2%) and 287 (45.8%) patients underwent DHCA and MHCA, respectively. The overall incidence of AKI was 75.4%. Age [odds ratio (OR) 1.02, 95% confidence interval (CI) 1.00-1.04; P = 0.022], body mass index (OR 1.06, 95% CI 1.01-1.12; P = 0.016), cardiopulmonary bypass duration (OR 1.01, 95% CI 1.00-1.01; P = 0.003) and hypertension history (OR 1.76, 95% CI 1.14-2.70; P = 0.010) were identified as independent risk factors for AKI onset with multivariable analysis. Postoperative AKI was not significantly different between the DHCA and MHCA groups regardless of the overall or propensity-matched cohort (overall data: P = 0.17; propensity score data: P = 0.88). Patients with MHCA experienced higher rates of postoperative stroke after propensity score analysis (DHCA 0.9% vs MHCA 3.7%; P = 0.034).

CONCLUSIONS

MHCA was not superior to DHCA in decreasing postoperative AKI. Thus, MHCA should not definitively replace DHCA.

Aortic balloon occlusion technique versus moderate hypothermic circulatory arrest with antegrade cerebral perfusion in total arch replacement and frozen elephant trunk for acute type A aortic dissection

BACKGROUND

Moderate hypothermic circulatory arrest (MHCA) with antegrade cerebral perfusion (ACP) is safe and efficient in total arch replacement (TAR) and frozen elephant trunk (FET) for acute type A aortic dissection (ATAAD). Complications related to hypothermia and ischemia are inevitable, however. The aortic balloon occlusion (ABO) technique is performed to elevate the lowest nasopharyngeal temperature to 28°C and shorten the circulatory arrest time. In this study, we aimed to evaluate the efficacy of this new technique.

METHODS

We reviewed the clinical data of patients with ATAAD who underwent TAR and FET, including 79 who underwent ABO and 109 who underwent MHCA/ACP.

RESULTS

Circulatory arrest time was significantly lower in the ABO group compared with the MHCA/ACP group (mean, 4.8 ± 1.2 minutes vs 18.4 ± 3.1 minutes; P < .001). The composite endpoint was comparable in the 2 groups (11.4% for ABO vs 13.8% for MHCA/ACP; P = .631). Fewer patients in the ABO group developed high-grade acute kidney injury (AKI) according to a modified RIFLE criterion (22.8% vs 36.7%; P = .041), and the rate of hepatic dysfunction was lower in the ABO group (11.4% vs 28.4%; P = .005). Multivariable logistic analysis showed that the ABO technique is protective against duration of ventilation >24 hours (odds ratio [OR], 0.455; 95% confidence interval [CI], 0.234-0.887; P = .021), hepatic dysfunction (OR, 0.218; 95% CI, 0.084-0.561; P = .002), and grade II-III AKI (OR, 0.432; 95% CI, 0.204-0.915; P = .028).

CONCLUSIONS

The ABO technique significantly shortens the circulatory arrest time in TAR and FET. Available clinical data suggest that it has a certain protective effect on the liver and kidney. Future large-sample studies are warranted to thoroughly evaluate this new technique.

Deep Hypothermic Circulatory Arrest Does Not Show Better Protection for Vital Organs Compared with Moderate Hypothermic Circulatory Arrest in Pig Model

Background

Continued debates exist regarding the optimal temperature during hypothermic circulatory arrest in aortic arch repair for patients with type A aortic dissection. This study seeks to examine whether the use of moderate hypothermic circulatory arrest in a pig model provides comparable vital organ protection outcomes to the use of deep hypothermic circulatory arrest.

Methods

Thirteen pigs were randomly assigned to 30 minutes of hypothermic circulatory arrest without cerebral perfusion at 15°C (n = 5), 25°C (n = 5), and a control group (n = 3). The changes in standard laboratory tests and capacity for protection against apoptosis in different vital organs were monitored with different temperatures of hypothermic circulatory arrest management in pig model to determine which temperature was optimal for hypothermic circulatory arrest.

Results

There were no significant differences in the capacity for protection against apoptosis in vital organs between 2 groups (p > 0.05, respectively). Compared with the moderate hypothermic circulatory arrest group, the deep hypothermic circulatory arrest group had no significant advantages in terms of the biologic parameters of any other organs (p > 0.05).

Conclusions

Compared with deep hypothermic circulatory arrest, moderate hypothermic circulatory arrest is a moderate technique that has similar advantages with regard to the levels of biomarkers of injury and capacity for protection against apoptosis in vital organs.

[Hibrid surgical treatment of an aortic arch aneurysm]

Presented in the article is a clinical case report regarding hybrid surgical management of a saccular aneurysm of the aortic arch: simultaneous right-left-carotid-left-subclavian bypass grafting and endovascular isolation of the aneurysm. Taking into consideration the findings of multislice computed tomography-aortography (MSCT aortography) prior to surgery, the anatomical location of the aneurysm with the involvement of the ostium of the left subclavian artery, close location of the proximal branches of the aortic arch at an acute angle relative to each other required performing simultaneous debranching in order to enlarge the proximal zone of fixation of a stent graft at the level of the brachiocephalic trunk (BCT). The postoperative period proved uneventful, with as rapid rehabilitation as possible. From our own experience, with this one being not the first similar operation performed in the Centre, it may be supposed that carrying out simultaneous hybrid interventions in treatment of aneurysms of the aortic arch with the use of different variants of switching its branches may decrease the frequency of postoperative complications for patients of high surgical risk, reduce the length of hospital stay and, consequently, economic expenditures for treatment.

Targeted Temperature Management With Total Liquid Ventilation After Ischemic Spinal Cord Injury

BACKGROUND

Ischemic spinal cord injury is a devastating condition after aortic surgery. We determined whether ultrafast and short whole-body hypothermia provided by total liquid ventilation (TLV) attenuated lower limb paralysis after aortic cross-clamping with a targeted temperature management at 33°C versus 36°C.

METHODS

Anesthetized rabbits were submitted to infrarenal aortic cross-clamping during 15 min. A control group (n = 7) was maintained at normothermia (38°C to 38.5°C) with conventional mechanical ventilation. In TLV groups, TLV was started after reperfusion and maintained during 30 min with a target temperature at either 33°C or 36°C (TLV-33°C and TLV-36°C, respectively; n = 7 in each condition). After TLV, animals were resumed to conventional ventilation. Hypothermia was maintained during 120 min, before rewarming and awakening. Hind limb motor function was assessed with modified Tarlov score at day 2 and infarct size in the spinal cord was determined using triphenyltetrazolium chloride staining.

RESULTS

Target temperature was achieved within 20 minutes in the two TLV groups. At day 2, the modified Tarlov score was significantly lower in the control group, as compared with TLV-33°C and TLV-36°C groups (0.0 ± 0.0 versus 3.1 ± 0.7 and 2.6 ± 0.6, respectively). The infarct size of the spinal cord was also significantly higher in the control group compared with TLV-33°C and TLV-36°C groups (75% ± 10% versus 32% ± 7% and 28% ± 10%, respectively). Neither motor function nor infarct size differed significantly between TLV-33°C and TLV-36°C groups.

CONCLUSIONS

Ultrafast hypothermic TLV attenuates spinal cord injury when applied after ischemic insult. Neurological outcome was similar with targeted temperature management at either 33°C or 36°C.

Effects of 4 major brain protection strategies during aortic arch surgery: A protocol for a systematic review and network meta-analysis using Stata

BACKGROUND

Reliable brain protection during aortic arch surgery remains a formidable surgical challenge. Various cerebral protection techniques have been used in the clinic; however, there is no consensus regarding which strategy is best. We will perform a network meta-analysis (NMA) focusing on the permanent neurological deficits (PND) and perioperative mortality associated with 4 major brain protection strategies used during aortic arch surgery.

METHODS

We will perform a literature search of MEDLINE, EMBASE, Cochrane Library, and PubMed databases. The primary outcomes of interest in this analysis will be PND and perioperative mortality. Inconsistencies in the NMA will be evaluated with global and local approaches. Network rank and surface under the cumulative ranking curve (SUCRA) analyses will be performed to evaluate and identify the superiority of different brain protection techniques.

RESULTS

This study is ongoing and will be submitted to a peer-reviewed journal for consideration of publication.

CONCLUSIONS

Our study will increase understanding of 4 major brain protection strategies during aortic arch surgery and be helpful to clinicians using NMA in their studies.

Zone zero hybrid arch exclusion versus open total arch replacement

Open total aortic arch replacement is one of the most technically demanding operations in cardiothoracic surgery, requiring operator expertise and intraoperative and postoperative teamwork. Despite current advancements in the field of open aortic surgery with regard to intraoperative brain protection and postoperative care, the morbidity and mortality associated with open total arch operations varies. Endovascular and hybrid procedures involving the use of zone 0 as a landing zone allow fair comparison between open total arch and hybrid operations. Hybrid procedures involving all of the other landing zones [1-4] should not be compared with open total arch replacement, as the extent of the pathology is different.