The impact of unilateral versus bilateral antegrade cerebral perfusion on surgical outcomes after aortic arch replacement: A propensity-matched analysis

Cerebral Protection Strategies in Aortic Arch Surgery-Past Developments, Current Evidence, and Future Innovation

Surgery of the aortic arch remains a complex procedure, with neurological events such as stroke remaining its most dreaded complications. Changes in surgical technique and the continuous innovation in neuroprotective strategies have led to a significant decrease in cerebral and spinal events. Different modes of cerebral perfusion, varying grades of hypothermia, and a number of pharmacological strategies all aim to reduce hypoxic and ischemic cerebral injury, yet there is no evidence indicating the clear superiority of one method over another. While surgical results continue to improve, novel hybrid and interventional techniques are just entering the stage and the question of optimal neuroprotection remains up to date. Within this perspective statement, we want to shed light on the current evidence and controversies of cerebral protection in aortic arch surgery, as well as what is on the horizon in this fast-evolving field. We further present our institutional approach as a large tertiary aortic reference center.

Meta-analysis: Bilateral and Unilateral Cerebral Perfusion in Type A Dissection

BACKGROUND

 This meta-analysis compared the outcomes of bilateral cerebral perfusion (BCP) and unilateral cerebral perfusion (UCP) in aortic surgery for acute type A aortic dissection.

METHODS

 A systematic literature search identified 12 studies involving 4,547 patients. Pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated to analyze perioperative characteristics, short-term mortality rates, and postoperative neurological complications.

RESULTS

 No significant differences were found between the BCP and UCP groups in terms of cardiopulmonary bypass time, aortic cross clamp time, lowest body temperature, and lower body circulatory arrest time. Short-term mortality rates (OR [95% CI] = 0.87 [0.64-1.19], p = 0.40) and permanent neurological deficits (OR [95% CI] = 1.01 [0.69-1.47], p = 0.96) were comparable between the groups. However, subgroup analysis of studies exclusively involving total arch replacement showed a lower short-term mortality rate (OR [95% CI] = 0.42 [0.28-0.63], p < 0.01) and permanent neurological deficits (OR [95% CI] = 0.53 [0.30-0.92], p = 0.03) in the BCP group. The BCP group also had a lower rate of temporary neurological deficits (OR [95% CI] = 0.70 [0.53-0.93], p = 0.01), particularly in studies exclusively involving total arch replacement (OR [95% CI] = 0.58 [0.40-0.85], p < 0.01).

CONCLUSION

 This meta-analysis suggests that BCP and UCP yield comparable outcomes. However, BCP may be associated with lower short-term mortality rates and reduced incidence of neurological complications, particularly in cases requiring total arch replacement. BCP should be considered as a preferred cerebral perfusion in specific patient populations.

Hybrid Treatment of Complex Diseases of the Aortic Arch and Descending Thoracic Aorta by Frozen Elephant Trunk Technique

The surgical management of acute and chronic complex diseases involving the aortic arch and the descending thoracic aorta remains challenging. Hybrid procedures associating total open arch replacement and stent-grafting of the proximal descending aorta were developed to allow a potential single-stage treatment, promote remodeling of the downstream aorta, and facilitate a potential second-stage thoracic endovascular aortic repair by providing an ideal landing zone. While these approaches initially used various homemade combinations of available conventional prostheses and stent-grafts, the so-called frozen elephant trunk technique emerged with the development of several custom-made hybrid prostheses. The aim of this study was to review the contemporary outcomes of this technique in the management of complex aortic diseases, with a special focus on procedural planning, organ protection and monitoring, refinements in surgical techniques, and long-term follow-up.

Bilateral Axillary Artery Perfusion in Total Arch Replacement

BACKGROUND

The site of arterial cannulation is an important consideration in the prevention of cerebral infarction after total arch replacement. We compared the outcomes of cannulation of the bilateral axillary artery, the femoral artery, and central cannulation in total arch replacement.

METHODS

Enrolled were 242 patients, categorized into three groups according to the arterial cannulation site used: bilateral axillary artery group, 124 patients; femoral artery group, 88 patients; central cannulation group, 30 patients. Selective cerebral perfusion was used for brain protection in all patients. Surgical outcomes, including the incidence of postoperative cerebral infarction, were compared between the groups.

RESULTS

Cardiopulmonary bypass time and lower-body circulatory arrest time were significantly shorter in the bilateral axillary artery group. Frozen elephant trunk procedure was performed in 54% of the bilateral axillary artery group (P < .001), and concomitant coronary artery bypass graft surgery was performed in 40% of the central cannulation group (P < .01). Hospital mortality in the bilateral axillary artery group was 1.6%, compared with 1.1% in the femoral artery group, and 0% in the central cannulation group (P = .72). The incidence of permanent neurologic deficit was significantly lower in the bilateral axillary artery group (0.8%) than in the central cannulation group (13%; P = .02). Logistic regression analysis indicated that bilateral axillary artery perfusion was a significant factor in the prevention of permanent neurologic deficit (odds ratio 0.10, P = .03).

CONCLUSIONS

Recent technical advances using bilateral axillary artery perfusion and frozen elephant trunk technique were associated with shortening cardiopulmonary bypass time and prevention of postoperative cerebral infarction in total arch replacement.

Cerebral Perfusion and Neuromonitoring during Complex Aortic Arch Surgery: A Narrative Review

Complex ascending and aortic arch surgery requires the implementation of different cerebral protection strategies to avoid or limit the probability of intraoperative brain damage during circulatory arrest. The etiology of the damage is multifactorial, involving cerebral embolism, hypoperfusion, hypoxia and inflammatory response. These protective strategies include the use of deep or moderate hypothermia to reduce the cerebral oxygen consumption, allowing the toleration of a variable period of absence of cerebral blood flow, and the use of different cerebral perfusion techniques, both anterograde and retrograde, on top of hypothermia, to avoid any period of intraoperative brain ischemia. In this narrative review, the pathophysiology of cerebral damage during aortic surgery is described. The different options for brain protection, including hypothermia, anterograde or retrograde cerebral perfusion, are also analyzed, with a critical review of the advantages and limitations under a technical point of view. Finally, the current systems of intraoperative brain monitoring are also discussed.

Initial Surgical Strategy for the Treatment of Type A Acute Aortic Dissection: Does Proximal or Distal Extension of the Aortic Resection Influence the Outcomes?

(1) Background: We sought to analyze and compare the outcomes in terms of early and late mortality and freedom from a redo operation in patients undergoing surgical treatment for a type A acute aortic dissection in relation to the initial surgical treatment strategy, i.e., proximal or distal extension of the aortic segment resection, compared with isolated resection of the supracoronary ascending aorta. (2) Methods: This is a retrospective study in which we included 269 patients who underwent operations for a type A acute aortic dissection in the Department of Cardiac Surgery of Tor Vergata University from May 2006 to May 2016. The patients were grouped according to the extent of the performed surgical treatment: isolated replacement of the supracoronary ascending aorta (NE, no extension), replacement of the aortic root (PE, proximal extension), replacement of the aortic arch (DE, distal extension), and both (BE, bilateral extension). The analyzed variables were in-hospital mortality, postoperative complications (incidence of neurological damage, renal failure and need for prolonged intubation), late mortality and need for a redo operation. (3) Results: Unilateral cerebral perfusion was performed in 49.3% of the patients, and bilateral perfusion—in 50.6%. The overall in-hospital mortality was 31.97%. In the multivariate analysis, advanced age, cardiopulmonary bypass time and preoperative orotracheal intubation were independent predictors of in-hospital mortality. In the population of patients who survived the surgery, the probability of survival at 92 months was 70 ± 5%, the probability of freedom from a redo operation was 71.5 ± 5%, the probability of freedom from the combined end-point death and a redo operation was 50 ± 5%. The re-intervention rate in the general population was 16.9%. The overall probability of freedom from re-intervention was higher in patients undergoing aortic root replacement, although not reaching a level of statistical significance. Patients who underwent aortic arch treatment showed reduced survival. (4) Conclusions: In the treatment of type A acute aortic dissection, all the surgical strategies adopted were associated with satisfactory long-term survival. In the group of patients in which the aortic root had not been replaced, we observed reduced event-free survival.

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.

Risk factors for stroke after total aortic arch replacement using the frozen elephant trunk technique

OBJECTIVES

This study aimed to analyse risk factors for postoperative stroke, evaluate the underlying mechanisms and report on outcomes of patients suffering a postoperative stroke after total aortic arch replacement using the frozen elephant trunk technique.

METHODS

Two-hundred and fifty patients underwent total aortic arch replacement via the frozen elephant trunk technique between March 2013 and November 2020 for acute and chronic aortic pathologies. Postoperative strokes were evaluated interdisciplinarily by a cardiac surgeon, neurologist and radiologist, and subclassified to each's cerebral territory. We conducted a logistic regression analysis to identify any predictors for postoperative stroke.

RESULTS

Overall in-hospital was mortality 10% (25 patients, 11 with a stroke). A symptomatic postoperative stroke occurred in 42 (16.8%) of our cohort. Eight thereof were non-disabling (3.3%), whereas 34 (13.6%) were disabling strokes. The most frequently affected region was the arteria cerebri media. Embolism was the primary underlying mechanism (n = 31; 73.8%). Mortality in patients with postoperative stroke was 26.2%. Logistic regression analysis revealed age over 75 (odds ratio = 3.25; 95% confidence interval 1.20-8.82; P = 0.021), a bovine arch (odds ratio = 4.96; 95% confidence interval 1.28-19.28; P = 0.021) and an acute preoperative neurological deficit (odds ratio = 19.82; 95% confidence interval 1.09-360.84; P = 0.044) as predictors for postoperative stroke.

CONCLUSIONS

Stroke after total aortic arch replacement using the frozen elephant trunk technique remains problematic, and most lesions are of embolic origin. Refined organ protection strategies, and sophisticated monitoring are mandatory to reduce the incidence of postoperative stroke, particularly in older patients presenting an acute preoperative neurological deficit or bovine arch.

Anaesthetic-surgical guide in the treatment of ascending aorta and surgery of the ascending aorta and aortic arch. Consensus document of the Spanish Society of Cardiovascular and Endovascular Surgery and the Sociedad of Anaesthesiology, Resuscitation and Pain Therapy

Aortic pathology is always a challenge for the clinician, and must be diagnosed and treated by a multidisciplinary team due to the technical and technological complexity of the resources used. Ongoing efforts to implement a systematic, protocolized approach involving "Aortic teams" made up of cardiologists, cardiac surgeons, vascular surgeons, anaesthesiologists and radiologists, among others are now leading to improved outcomes. The aim of this consensus document drawn up by the Aortic working groups of the Spanish Society of Anaesthesiology, Resuscitation and Pain Therapy (SEDAR) and the Spanish Society of Thoracic and Cardiovascular Surgery (SECTCV) is to disseminate a set of working protocols. The latest consensus document of the European Association for Cardio-Thoracic Surgery (EACTS) and the European Society for Vascular Surgery (ESVS) define the concept of "AORTIC TEAM"(1). The aortic team should be closely involved from diagnosis to treatment and finally follow-up, and should be formed of cardiac and vascular surgeons working together with anaesthesiologists, cardiologists, radiologists and geneticists. Treatment of aortic pathologies should be centralised in large centres, because this is the only way to effectively understand the natural course of the disease, provide the entire range of treatment options under one umbrella and treat potential complications. A streamlined emergent care pathway (24/7 availability), adequate transportation and transfer capabilities, as well as rapid activation of the multidisciplinary team must be available. In light of the complexity and constant evolution of therapeutic options, we present this first version of the Anaesthesiology and surgical guidelines for surgery of the ascending aorta and aortic arch. Some questions will no doubt remain unanswered, and future versions will include new techniques that, though implemented in some centres, are still not widely recommended.

Anaesthetic-surgical guide in the treatment of ascending aorta and surgery of the ascending aorta and aortic arch. Consensus document of the Spanish Society of Cardiovascular and Endovascular Surgery and the Sociedad of Anaesthesiology, Resuscitation and Pain Therapy

Aortic pathology is always a challenge for the clinician, and must be diagnosed and treated by a multidisciplinary team due to the technical and technological complexity of the resources used. Ongoing efforts to implement a systematic, protocolized approach involving "Aortic teams" made up of cardiologists, cardiac surgeons, vascular surgeons, anaesthesiologists and radiologists, among others are now leading to improved outcomes. The aim of this consensus document drawn up by the Aortic working groups of the Spanish Society of Anaesthesiology, Resuscitation and Pain Therapy (SEDAR) and the Spanish Society of Thoracic and Cardiovascular Surgery (SECTCV) is to disseminate a set of working protocols. The latest consensus document of the European Association for Cardio-Thoracic Surgery (EACTS) and the European Society for Vascular Surgery (ESVS) define the concept of "AORTIC TEAM"(1). The aortic team should be closely involved from diagnosis to treatment and finally follow-up, and should be formed of cardiac and vascular surgeons working together with anaesthesiologists, cardiologists, radiologists and geneticists. Treatment of aortic pathologies should be centralised in large centres, because this is the only way to effectively understand the natural course of the disease, provide the entire range of treatment options under one umbrella and treat potential complications. A streamlined emergent care pathway (24/7 availability), adequate transportation and transfer capabilities, as well as rapid activation of the multidisciplinary team must be available. In light of the complexity and constant evolution of therapeutic options, we present this first version of the Anaesthesiology and surgical guidelines for surgery of the ascending aorta and aortic arch. Some questions will no doubt remain unanswered, and future versions will include new techniques that, though implemented in some centres, are still not widely recommended.

Modified Distal Aortic Arch Occlusion During Aortic Arch Replacement

BACKGROUND

Circulatory arrest has been identified as an independent risk factor related to postoperative mortality in patients with Stanford type A aortic dissection. This study described a modified technique for distal aortic arch occlusion that markedly shortened the circulatory arrest time. The early results are encouraging.

METHODS

From May 2016 to September 2018, 51 patients with Stanford type A aortic dissection underwent the modified procedure for aortic arch replacement. All operations were performed via transitory circulatory arrest by clamping the distal aorta between the left common carotid artery and the left subclavian artery. The in-hospital and follow-up data of the treated patients were investigated.

RESULTS

Successful repair of the involved vasculature was achieved in all patients. One (1) patient died due to postoperative aspiration and infection, and three patients required continuous renal replacement therapy due to poor preoperative renal function. The remaining patients were successfully discharged. The median average circulatory arrest time was 5.0 (3.0-6.0) minutes. No cases of tracheotomy, delayed closure, secondary thoracotomy, or other complications occurred. During the follow-up period of 2.4-18.6 months, the implanted grafts and stented elephant trunks were all fully open and not kinked.

CONCLUSIONS

A modified distal aortic arch occlusion can considerably shorten the duration of circulatory arrest. Current experience suggests that this approach can serve as a feasible alternative for patients during aortic arch replacement because of its simplicity and satisfactory clinical effects.

Comparison of Femoral and Axillary Artery Cannulation in Acute Type A Aortic Dissection Surgery

INTRODUCTION

One of the most important points of the acute type A aortic dissection surgery is how to perform cannulation regarding cerebral protection concerns and the conditions of arterial structures as a pathophysiological consequence of the disease.

OBJECTIVE

In this study, femoral and axillary cannulation methods were compared in acute type A aortic dissection operations.

METHODS

The study retrospectively evaluated 52 patients who underwent emergency surgery for acute type A aortic dissection. Patients without malperfusion according to Penn Aa classification were chosen for preoperative standardization of the study groups. The femoral arterial cannulation group was group 1 (n=22) and the axillary arterial cannulation group was group 2 (n=30). The groups were compared in terms of perioperative and postoperative results.

RESULTS

There was no statistically significant difference in terms of preoperative data. In terms of postoperative parameters, especially early mortality and new-onset cerebrovascular event, there was no statistically significant difference. Mortality rates in group 1 and group 2 were 13.6% (n=3) and 10% (n=3), respectively (P=0.685). Postoperative new-onset cerebral events ratio was found in 5 (22.7%) in the femoral cannulation group and 6 (20%) in the axillary cannulation group (P=0.812).

CONCLUSION

Both femoral and axillary arterial cannulation methods can be safely performed in patients with acute type A aortic dissection, provided that cerebral protection strategies should be considered in the first place. The method to be performed may vary depending on the patient's current medical condition or the surgeon's preference.

Cannulation strategies, circulation management and neuroprotection for type A intramural hematoma: tips and tricks

The circulation management strategies and operative techniques that are essential for the successful surgical repair of acute type A intramural hematoma (ATAIMH) are similar to those utilized for acute type A aortic dissection. This article reviews the neuroprotection strategies and arterial cannulation sites used in the treatment of patients with ATAIMH.

A functional assessment of the circle of Willis before aortic arch surgery using transcranial Doppler

BACKGROUND

Antegrade selective cerebral perfusion (ASCP) with systemic moderate hypothermia is routinely used as brain protection during aortic arch surgery. Whether ASCP should be delivered unilaterally (u-ASCP) or bilaterally (bi-ASCP) remains controversial.

METHODS

We routinely studied the functional anatomy of the circle of Willis (CoW in all patients scheduled for arch surgery using transcranial color-coded Doppler over a decade. On the basis of these data, we classified observed functional variants as being "safe," "moderately safe," or "unsafe" for u-ASCP.

RESULTS

From January 2005 to June 2015, 1119 patients underwent aortic arch surgery in our institution. Of these, 636 patients had elective surgery performed with ASCP. Preoperative full functional assessment of the CoW was possible in 61% of patients. A functionally complete CoW was found in only 27%. Of all variants, 72% were classified as being safe for u-ASCP, whereas 18% were moderately safe for u-ASCP, and 10% unsafe. Unsafe variants for bi-ASCP were observed in 0.5% of patients.

CONCLUSIONS

The risk of ischemic brain damage due to malperfusion is estimated to be substantially higher during right u-ASCP than during bi-ASCP. Bi-ASCP is therefore highly preferable over u-ASCP if the function of the CoW is unknown. We propose a tailored approach using this full functional assessment preoperatively by applying u-ASCP via the right subclavian artery when considered safely possible, and bi-ASCP when considered a necessity to prevent cerebral malperfusion, and thus thereby try to reduce the embolic stroke risk of ostial instrumentation in bi-ASCP.

[Predictors of neurological complications during surgical treatment of the ascending aorta and aortic arch chronic dissection]

AIM

To evaluate the prognostic significance of oxygen supply to the brain in the risk of neurological complications in the early post operative period of surgical treatment of the ascending aorta and aortic arch.

MATERIAL AND METHODS

The level of oxygenation (rSO2) in the right and left hemispheres was measured in 68 patients with ascending aorta and aortic arch chronic dissection. Before and in the nearest period after surgery, the patients underwent a clinical/instrumental neurological study.

RESULTS

The incidence of ischemic stroke in the early post operative period was 5.9%, cognitive impairment was recorded in 22% of patients. Among the parameters of oxygen supply to the brain, the dynamics of rSO2 during circulatory arrest had a significant impact on the post operative neurological status. The risk of cognitive impairment, besides the association with the oxygen status of the brain, increased with the age of patients and comorbid pathology.

CONCLUSION

The decrease in rSO2 by ≥30% during surgical treatment of ascending aorta and aortic arch dissection increases the risk of ischemic stroke and cognitive impairment in the early post operative period.

An innovative arch-first surgical procedure under moderate hypothermia for acute type A aortic dissection

BACKGROUND

We hypothesized that the arch-first procedure without extra devices under moderate-to-mild systemic hypothermia during acute type A aortic dissection is safe and efficient and will improve patient outcome compared with the standard total arch replacement technique.

METHODS

From December 2014 to February 2017, 89 patients were enrolled in this study, 52 of whom underwent conventional deep hypothermic circulatory arrest (DHCA, 24.2±0.71 °C) using the antegrade cerebral perfusion surgical procedure (Group A) and 37 of whom underwent the "arch-first" technique with moderate (27.4±1.1 °C) systemic hypothermia during antegrade cerebral perfusion (Group B). The clinical data, surgical and postoperative data, complications, and mortality of the two groups were analyzed.

RESULTS

The cardiopulmonary bypass (171.3±40.0 min) and awakening time (7.0 hours) was significantly decreased in Group B. Two patients died 30 d after surgery (5.4%, two of 37) in Group B. The incidence of transient neurologic deficit (2.7%) and distal organ complications (5.4%) was lower in Group B.

CONCLUSIONS

In patients with acute type A aortic dissection involving the arch, the innovative arch-first surgical procedure could provide feasible and safe treatment outcomes, which brings us closer to the goal of performing surgery with moderate-to-mild systemic hypothermia with better cerebral, distal organ, and survival outcomes.

Intraoperative care for aortic surgery using circulatory arrest

The total circulatory arrest (CA) is necessary to achieve optimal surgical conditions in certain aortic pathologies, especially in those affecting the ascending aorta and aortic arch. During this procedure it is necessary to protect all the organs of ischemia, especially those of the central nervous system and for this purpose several strategies have been developed. The first and most important protective method is systemic hypothermia. The degree of hypothermia and the route of application have been evolving and currently tend to use moderate hypothermia (MH) (20.1-28 °C) associated with unilateral or bilateral selective cerebral perfusion methods. In this way the neurological results are better, the interval of security is greater and the times of extracorporeal circulation are smaller. Even so, it is necessary to take into account that there is the possibility of ischemia in the lower part of the body, especially of the abdominal viscera and the spinal cord, therefore the time of circulatory stop should be limited and not to exceed 80 minutes. Evidence of possible neurological drug protection is very weak and only mannitol, magnesium, and statins can produce some benefit. Inhalational anesthetics and some intravenous seem to have advantages, but more studies would be needed to test their long-term benefit. Other important parameters to be monitored during these procedures are blood glucose, anemia and coagulation disorders and acid-base balance. The recommended monitoring is common in complex cardiovascular procedures and it is of special importance the neurological monitoring that can be performed with several techniques, although currently the most used are Bispectral Index (BIS) and Near-Infrared Spectroscopy (NIRS). It is also essential to monitor the temperature routinely at the nasopharyngeal and bladder level and it is important to control coagulation with rotational thromboelastometry (ROTEM).

Bilateral versus unilateral antegrade cerebral perfusion in total arch replacement for type A aortic dissection

BACKGROUND

Antegrade cerebral perfusion (ACP) is the most widely used cerebral protection strategy for complex aortic repair and includes unilateral (u-ACP) and bilateral (b-ACP) techniques. The superiority of b-ACP over u-ACP has been the subject of much debate. Focusing on type A aortic dissection requiring total arch replacement, we investigated the clinical effects of b-ACP versus u-ACP.

METHODS

Between September 2006 and August 2014, 203 patients presenting with type A aortic dissection (median age, 51.0 ± 13 years; range, 17-72 years; 128 males) underwent total aortic arch replacement with hypothermic circulatory arrest. ACP was used in all patients, including u-ACP in 82 (40.3%) and b-ACP in 121 (59.7%).

RESULTS

There was no significant difference between the u-ACP and b-ACP groups in terms of cardiopulmonary bypass (CPB) time, cross-clamp time, or circulatory arrest time. Overall 30-day mortality was comparable in the 2 groups (11.6% for b-ACP vs 20.7% for u-ACP; P = .075). The prevalence of postoperative permanent neurologic dysfunction (PND) was comparable as well (8.4% vs 16.9%; P = .091). Mean ventilation time was lower in the b-ACP group (95.5 ± 45.25 hours vs 147.0 ± 82 hours; P < .001). Mean lengths of stay in the intensive care unit and the hospital overall were comparable in the 2 groups (intensive care unit: 16 ± 17.75 days vs 17 ± 11.5 days, P = .454; hospital: 26.5 ± 20.6 days vs 24.8 ± 10.3 days, P = .434). The P values from logistic regression models indicated that in the 2 groups combined, CPB time and circulatory arrest time were independent risk factors for both mortality and PND.

CONCLUSIONS

In this, the first published study focusing on the efficacy of u-ACP and b-ACP in total arch replacement for type A aortic dissection, the b-ACP group did not demonstrate significantly lower 30-day mortality or PND rate compared with the u-ACP group. Future large-sample studies are warranted to thoroughly examine this critical issue.

Temperature Management for Aortic Arch Surgery

Surgical treatment of aortic arch disease is a technically challenging procedure that requires complex circulation management strategies involving the use of hypothermic circulatory arrest. The definition of hypothermia has evolved with comfort and surgical adjuncts. This review describes the various circulation and temperature management strategies used during hemiarch and total arch replacement.

Multicentre analysis of current strategies and outcomes in open aortic arch surgery: heterogeneity is still an issue

OBJECTIVES

The study was conducted to evaluate, on the basis of a multicentre analysis, current results of elective open aortic arch surgery performed during the last decade.

METHODS

Data of 1232 consecutive patients who underwent aortic arch repair with reimplantation of at least one supra-aortic artery between 2004 and 2013 were collected from 11 European cardiovascular centres, and retrospective statistical examination was performed using uni- and multi-variable analyses to identify predictors for 30-day mortality. Acute aortic dissections and arch surgeries not involving the supra-aortic arteries were not included.

RESULTS

Arch repair involving all 3 arch arteries (total), 2 arch arteries (subtotal) or 1 arch artery (partial) was performed in 956 (77.6%), 155 (12.6%) and 121 (9.8%) patients, respectively. The patients' characteristics as well as the surgical techniques, including the method of cannulation, perfusion and protection, varied considerably between the clinics participating in the study. The in-hospital and 30-day mortality rates were 11.4 and 8.8% for the entire cohort, respectively, ranging between 1.7 and 19.0% in the surgical centres. Multivariable logistic regression analysis identified surgical centre, patient's age, number of previous surgeries with sternotomy and concomitant surgeries as independent risk factors of 30-day mortality. The follow-up of the study group was 96.5% complete with an overall follow-up duration of 3.3 ± 2.9 years, resulting in 4020 patient-years. After hospital discharge, 176 (14.3%) patients died, yielding an overall mortality rate of 25.6%. The actuarial survival after 5 and 8 years was 72.0 ± 1.5% and 64.0 ± 2.0, respectively.

CONCLUSIONS

The surgical risk in elective aortic arch surgery has remained high during the last decade despite the advance in surgical techniques. However, the patients' characteristics, numbers of surgeries, the techniques and the results varied considerably among the centres. The incompleteness of data gathered retrospectively was not effective enough to determine advantages of particular cannulation, perfusion, protection or surgical techniques; and therefore, we strongly recommend further prospective multicentre studies, preferably registries, in which all relevant data have to be clearly defined and collected.

Trifurcated graft replacement of the aortic arch: state of the art

OBJECTIVE

To review the contemporary practice in total arch replacement (TAR) by using the trifurcated graft technique.

METHODS

The evolution of the trifurcated graft technique in total arch replacement is described. Axillary artery perfusion with antegrade cerebral perfusion (ACP) is routinely performed, with systemic deep hypothermia based on the anticipated interval of lower body ischemia. Cerebral oxygen saturation is monitored and bilateral ACP (BACP) is performed if the adequacy of collateral circulation is questioned. Potential advantages and disadvantages of unilateral ACP (UACP) vs BACP are discussed.

RESULTS

The advantage of the trifurcated graft technique in TAR is that it facilitates the creation of an "elephant trunk" in the proximal arch, making the operation technically easier and avoiding the risk of recurrent laryngeal nerve injury. The technique is also versatile in a variety of aortic arch anatomies and pathologies, while enabling continuous ACP without hypothermic circulatory arrest for cerebral protection. UACP during TAR is acceptable for shorter intervals (<30-40 minutes) if combined with moderate hypothermia. BACP should be considered for prolonged ACP interval or if left cerebral oxygenation is inadequate during UACP.

CONCLUSIONS

The trifurcated graft technique is a versatile method in TAR that can be applied to a diverse range of aortic anatomies, pathologies and hybrid arch procedures, with concomitant or staged endovascular options. UACP or BACP and lower body ischemia can be performed without adding significant complexity to the procedure, while conferring maximal cerebral, spinal, and lower body protection.

Research progress on combat trauma treatment in cold regions

Cold regions are a special combat environment in which low temperatures have a great impact on human metabolism and other vital functions, including the nervous, motion, cardiovascular, circulatory, respiratory, and urinary systems; consequently, low temperatures often aggravate existing trauma, leading to high mortality rates if rapid and appropriate treatment is not provided. Hypothermia is an independent risk factor of fatality following combat trauma; therefore, proactive preventative measures are needed to reduce the rate of mortality. After summarizing the basic research on battlefield environments and progress in the prevention and treatment of trauma, this article concludes that current treatment and prevention measures for combat trauma in cold regions are inadequate. Future molecular biology studies are needed to elucidate the mechanisms and relevant cell factors underlying bodily injury caused by cold environment, a research goal will also allow further exploration of corresponding treatments.