Innominate and Axillary Cannulation in Aortic Arch Surgery Provide Similar Neuroprotection

The Call for the "Interventional/Hybrid" Aortic Surgeon: Open, Endovascular, and Hybrid Therapies of the Aortic Arch

Aortic arch pathology is relatively rare but potentially highly fatal and associated with considerable comorbidity. Operative mortality and complication rates have improved over time but remain high. In response, aortic arch surgery is one of the most rapidly evolving areas of cardiac surgery in terms of surgical volume and improved outcomes. Moreover, there has been a surge in novel devices and techniques, many of which have been developed by or codeveloped with vascular surgeons and interventional radiologists. Nevertheless, the extent of arch surgery, the choice of nadir temperature, cannulation, and perfusion strategies, and the use of open, endovascular, or hybrid options vary according to country, centre, and surgeon. In this review article, we provide a technical overview of the surgical, total endovascular, and hybrid repair options for aortic arch pathology through historical developments and contemporary results. We highlight key information for surgeons, cardiologists, and trainees to understand the management of patients with aortic arch pathology. We conclude by discussing training paradigms, the role of aortic teams, and gaps in knowledge, arguing for the need for wire skills for the future "interventional aortic surgeon" and increased research into techniques and novel devices to continue improving outcomes for aortic arch surgery.

Femoral artery cannulation increases the risk of postoperative stroke in patients with acute DeBakey I aortic dissection

BACKGROUND

The selection of different arterial cannulation site influences the incidence of postoperative stroke in patients with DeBakey I acute aortic dissection. The study aimed to explore the optimal arterial cannulation for these patients.

METHODS

From January 2009 to 2019, a total of 1514 patients with DeBakey I acute aortic dissection underwent frozen elephant trunk and total arch replacement at a tertiary center. They were divided into 2 groups: the axillary artery only cannulation group (n = 1075) and the femoral artery cannulation group (n = 439). After balancing the differences of baseline condition by propensity score matching, the prognosis was compared.

RESULTS

The incidence of stroke and acute brain infarction in the femoral artery cannulation group was higher than in the axillary artery only cannulation group (stroke, 11.7% vs 7.0%, P = .03; acute brain infarction, 6.0% vs 2.7%, P < .01). The femoral artery cannulation group was further divided into 2 groups: femoral artery only cannulation group (n = 106) and axillary combined with femoral artery cannulation group (n = 333). The comparison was performed between the axillary combined with femoral artery cannulation group and the axillary artery only cannulation group. After propensity score matching, the incidence of stroke and acute brain infarction in the axillary combined with femoral artery cannulation group was higher than in the axillary artery only cannulation group (stroke, 13.5% vs 7.2%, P < .01; acute brain infarction, 6.9% vs 2.5%, P < .01).

CONCLUSIONS

Axillary artery only cannulation is recommended as the optimal arterial cannulation strategy for most patients with DeBakey I acute aortic dissection. For those patients who are not suitable for axillary artery only cannulation, axillary combined with femoral artery cannulation is not recommended.

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.

Direct proximal right subclavian artery cannulation during surgery of the thoracic aorta

OBJECTIVE

To evaluate outcomes of single sternum access for right subclavian artery cannulation without infraclavicular incision in surgery of the thoracic aorta.

METHODS

Between January 2015 and December 2019, 44 consecutive patients underwent surgery of the thoracic aorta with cannulation of the right subclavian artery, after sternotomy and before pericardiotomy, through a direct percutaneous cannula with a single access without additional infraclavicular skin incision. The indication for surgery was type A acute aortic dissection in 29 patients (65.9%), proximal aortic aneurysm in 11 (25%), and aneurysm of the aortic arch in 4 (9%). Operative procedures were replacement of the ascending aorta in 23 patients, Bentall procedure in 10, hemiarch replacement in 6, and total arch replacement in 5. The mean cardiopulmonary bypass (CPB) and cross-clamp times were 185 ± 62 minutes and 138 ± 41 minutes, respectively.

RESULTS

The in-hospital mortality rate was 6.8%. Permanent neurologic dysfunction occurred in 3 patients (6.8%) and temporary neurologic dysfunction occurred in 4 patients (9.0%). There were no vascular complications related to this technique. No lesions to the vagus and recurrent laryngeal nerves have been reported.

CONCLUSIONS

In our experience, a single sternum access for right subclavian artery cannulation avoids the risk and complications of an infraclavicular incision required for axillary artery cannulation. This technique is safe and represent a valid option for CBP and antegrade cerebral perfusion during surgery of the thoracic aorta.

A randomized trial comparing axillary versus innominate artery cannulation for aortic arch surgery

BACKGROUND

Cerebral protection remains the cornerstone of successful aortic surgery; however, there is no consensus as to the optimal strategy.

OBJECTIVE

To compare the safety and efficacy of innominate to axillary artery cannulation for delivering antegrade cerebral protection during proximal aortic arch surgery.

METHODS

This randomized controlled trial (The Aortic Surgery Cerebral Protection Evaluation CardioLink-3 Trial, ClinicalTrials.gov Identifier: NCT02554032), conducted across 6 Canadian centers between January 2015 and June 2018, allocated 111 individuals to innominate or axillary artery cannulation. The primary safety outcome was neuroprotection per the appearance of new severe ischemic lesions on the postoperative diffusion-weighted-magnetic resonance imaging. The primary efficacy outcome was the difference in total operative time. Secondary outcomes included 30-day all-cause mortality and postoperative stroke.

RESULTS

One hundred two individuals (mean age, 63 ± 11 years) were in the primary safety per-protocol analysis. Baseline characteristics between the groups were similar. New severe ischemic lesions occurred in 19 participants (38.8%) in the axillary versus 18 (34%) in the innominate group (P for noninferiority = .0009). Total operative times were comparable (median, 293 minutes; interquartile range, 222-411 minutes) for axillary versus (298 minutes; interquartile range, 231-368 minutes) for innominate (P for superiority = .47). Stroke/transient ischemic attack occurred in 4 (7.1%) participants in the axillary versus 2 (3.6%) in the innominate group (P = .43). Thirty-day mortality, seizures, delirium, and duration of mechanical ventilation were similar in both groups.

CONCLUSIONS

diffusion-weighted magnetic resonance imaging assessments indicate that antegrade cerebral protection with innominate cannulation is safe and affords similar neuroprotection to axillary cannulation during aortic surgery, although the burden of new neurological lesions is high in both groups.

A simple method to establish antegrade cerebral perfusion during hemiarch reconstruction

Objective

We describe a novel and safe technique using a 12F-14F pediatric arterial cannula to establish unilateral, selective, antegrade cerebral perfusion (ACP) during open hemiarch reconstruction.

Methods

Between January 2015 and September 2018, 42 patients underwent elective aortic aneurysm repair requiring an open distal anastomosis and at least a hemiarch replacement via hypothermic circulatory arrest by 2 surgeons. All distal reconstructions were performed at moderate hypothermia (22°C-26°C) with direct cannulation of the innominate artery (IA) using a pediatric arterial cannula to allow ACP at 10-15 mL/kg/min. Data were collected by retrospective chart review.

Results

Thirty-one of the 42 patients (74%) were male. The mean patient age was 65 ± 13 years, and the mean body surface area was 2.1 ± 0.3 m². Proximal repairs included a modified Bentall with a valve-graft composite (n = 17), valve-sparing root replacement (n = 2), and aortic valve replacement (n = 15). Perioperative mortality was 2% (n = 1), and the incidence of stroke was 0%. The mean lowest core body temperature reached during circulatory arrest was 23.8 ± 2.7°C with a mean ACP time of 21.8 ± 3.6 minutes. The mean aortic cross-clamp and cardiopulmonary bypass times were 160.6 ± 55.5 minutes and 204.7 ± 57.5 minutes, respectively. There were no cases of IA injury.

Conclusions

Direct IA cannulation with a pediatric arterial cannula is a safe and efficient method to allow ACP in aortic surgery requiring hypothermic circulatory arrest and may circumvent the potential complications of axillary cannulation.

In thoracic aortic surgery, is innominate artery cannulation a safe and effective alternative to axillary artery cannulation?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was: in a patient undergoing thoracic aortic surgery, is innominate artery cannulation superior to axillary artery cannulation in terms of postoperative outcomes? Five hundred and thirty-one papers were found using the reported search strategy, of which 5 represented the best evidence to answer the clinical question. A total of 1338 participants were included across the 5 studies. Seven hundred and twenty-two patients were cannulated via the axillary artery and 616 were cannulated via the innominate artery. The included 5 studies were 2 prospective observational cohorts, 2 retrospective case-series analysis and a single-blinded randomized trial. Thirty-day or in-hospital mortality rates were reported in all 5 studies. There were no significant differences in mortality with innominate artery cannulation compared to axillary artery cannulation (P > 0.05), with slightly lower mortality rates in 2 studies, slightly higher mortality rates in 2 and equal in 1 study. Though statistical significance was not demonstrated (P > 0.05), a stroke occurred slightly less frequently in patients receiving innominate artery cannulation compared to axillary artery cannulation in 3 of the 4 studies. Innominate artery cannulation is non-inferior to axillary artery cannulation for thoracic aortic surgery, with a similar level of neuroprotection and is not associated with increased levels of mortality.

Proximal arterial cannulation in thoracic aortic surgery-Literature review

Surgery on thoracic aorta is complex with a number of approaches being required depending on the pathology and anatomy that is specific to each patient and therefore, careful planning is required to ensure successful outcomes. Among the key factors that determine a satisfactory and safe operation is the choice of arterial cannulation site to establish cardiopulmonary bypass and deliver brain protection adequately. Direct proximal aortic cannulation is the gold-standard method for elective aortic root surgery and traditionally femoral arterial cannulation has been used in complex aortic surgeries such as redo or acute pathologies; however, axillary and innominate artery (IA) cannulation has evolved dramatically and several centers are currently using proximal cannulation sites as the default cannulation choice in elective and emergency settings of complex thoracic aortic surgeries. The evidence behind cannulating the IA is growing; however, it is yet to be well established through large studies or trial to confirm its superiority to other methods of central cannulation techniques.

Innominate vs. Axillary Artery Cannulation in Aortic Surgery: a Systematic Review and Meta-Analysis

OBJECTIVE

To investigate whether axillary artery cannulation has supremacy over innominate artery cannulation in thoracic aortic surgery.

METHODS

A comprehensive search was undertaken among the four major databases (PubMed, Excerpta Medica dataBASE [EMBASE], Scopus, and Ovid) to identify all randomized and nonrandomized controlled trials comparing axillary to innominate artery cannulation in thoracic aortic surgery. Databases were evaluated and assessed up to March 2017.

RESULTS

Only three studies fulfilled the criteria for this meta-analysis, including 534 patients. Cardiopulmonary bypass time was significantly shorter in the innominate group (P=0.004). However, the innominate group had significantly higher risk of prolonged intubation > 48 hours (P=0.04) than the axillary group. Further analysis revealed no significant difference between the innominate and axillary groups for deep hypothermic circulatory arrest time (P=0.06). The relative risks for temporary and permanent neurological deficits as well as in-hospital mortality were not significantly different for both groups (P=0.90, P=0.49, and P=0.55, respectively). Length of hospital stay was similar for both groups.

CONCLUSION

There is no superiority of axillary over innominate artery cannulation in thoracic aortic surgery in terms of perioperative outcomes; however, as the studies were limited, larger scale comparative studies are required to provide a solid evidence base for choosing optimal arterial cannulation site.

Innominate artery cannulation in aortic surgery: A systematic review

OBJECTIVE

The innominate artery is considered an alternative site for establishing cardiopulmonary bypass in surgical procedures involving the thoracic aorta. This systematic review examines the use of innominate artery cannulation in aortic surgery.

METHODS

A systematic literature search was undertaken among the four major databases (PubMed, Embase, Scopus, and Ovid) to identify all studies that utilized innominate artery cannulation for establishing cardiopulmonary bypass and providing cerebral perfusion in thoracic aortic surgery. The data were reviewed up to September 2018.

RESULTS

Acute type A aortic dissection contributed to 36% (n = 818) of the total 2,290 patients. 31.5% (n = 719) underwent surgery on the aortic root only; 54.5% (n = 1246) had ascending and hemi-arch replacement, while 11.5% had total aortic arch replacement and 2.5% had a frozen elephant trunk inserted. Postoperative stroke rate was 1.25% (n = 28), temporary neurological deficit was 4.8% (n = 111). All-cause 30-day mortality rate was 2.7% (n = 61).

CONCLUSION

Innominate artery cannulation is a safe technique in patients who undergo thoracic aortic surgery. It can be utilized, in selected cases, as a reliable route for establishing cardiopulmonary bypass and maintaining cerebral perfusion.

Innominate Versus Axillary Artery Cannulation for the Hemiarch Repair

BACKGROUND

Innominate artery cannulation has gained some popularity over the last decade as an alternative to axillary artery cannulation for providing selective antegrade cerebral perfusion during repair of the ascending aorta and arch. Innominate artery cannulation provides several advantages including avoidance of an additional incision and use of a larger caliber artery to provide less resistance to high flow during bypass and selective antegrade cerebral perfusion. We hypothesize that these advantages make innominate artery cannulation superior to axillary artery cannulation as it can decrease operative times and potentially decrease blood loss.

METHODS

This was a single-center retrospective analysis of 206 patients who underwent hemiarch replacement between 2009 and 2017. All patients qualified including emergent cases. Groups were separated by mode of cannulation: axillary and innominate. Outcomes evaluated included cardiopulmonary bypass (CPB) time, cross-clamp time, circulatory arrest (CA) time, postoperative transfusions, intensive care unit length of stay, development of any neurological complications, end-organ failure, and mortality. Subgroup analysis was performed for elective and emergent cases.

RESULTS

Axillary and innominate artery cannulation accounted for 37% (n = 77) and 67% (n = 129) of cases, respectively. There was no difference in patient characteristics except for a higher incidence of renal disease in the axillary group (16% versus 6%, P = 0.05). More emergent cases were performed in the axillary group (61% versus 17%, P < 0.001). Innominate cases had shorter CPB times (189 versus 150 min, P < 0.001) and CA (22.5 versus 11 min, P < 0.001) times overall. In the elective subgroup, CA times were shorter for the innominate cases. However, the emergent subgroup displayed no difference in operative times. Less transfusions were given in the innominate group including units of red blood cells (2 [0-6] versus 0 [0-2], P < 0.001), units of platelets (2 [1-3] versus 1 [0-2], P = 0.001), and units of plasma (6 [2-9] versus 2 [0-4], P < 0.001). A similar trend was observed in the elective subgroup. No difference in transfusions was observed in the emergent subgroup. There was no statistical difference in remaining outcomes between cases of axillary and innominate cannulation in the combined, elective, and emergent groups.

CONCLUSIONS

Alternate cannulation strategies for open arch anastomoses are evolving with a trend toward using the innominate artery. These data suggest that innominate cannulation is at least equivalent to, and may be superior to, axillary cannulation. The innominate artery provides a larger conduit vessel for perfusion and this decrease in resistance to flow, allowing for faster cooling and rewarming, maybe why CPB times were lower in this group. Innominate cannulation is a safe and potentially advantageous technique for hemiarch repair.

Whole body perfusion strategy for aortic arch repair under moderate hypothermia

INTRODUCTION

Aortic arch reconstruction under moderate hypothermia is commonly performed with antegrade cerebral perfusion (ACP) for brain protection; however, hypothermia alone is often solely relied upon for visceral and lower body protection. We investigated whether the addition of simultaneous lower body perfusion to ACP (whole body perfusion - WBP) may ameliorate the metabolic derangements of moderate hypothermic circulatory arrest (MHCA).

METHODS

Between 2008 and 2014, 106 consecutive patients underwent elective or emergent aortic arch surgery with MHCA, with either ACP only (44 patients, 66±12 years, 30% female) or WBP (62 patients, 61±15 years, 31% female). Primary outcomes included 30-day/in-hospital mortality, intensive care unit (ICU) and hospital lengths of stay (LOS) and specific parameters of metabolic recovery.

RESULTS

There were no significant differences between the groups in 30-day/in-hospital mortality (ACP: 3 (6.8%), WBP: 2 (3.2%); p=0.65), stroke (ACP: 1 (2.3%), WBP: 1 (1.6%); p=1.0) or renal failure (ACP: 2 (4.5%), WBP: 1 (1.5%); p=0.57). In the WBP group, we identified a significant reduction in lactate level at ICU admission (ACP 5.5 vs. WBP 3.5 mmol/L; p=0.002), time to lactate normalization (p=0.014) and median ICU length-of-stay (ACP 3 vs. WBP 1 days; p=0.049). There was no difference in post-operative creatinine (ACP: 104, WBP: 107 μmol/L; p=0.66). After multivariable regression adjustment, perfusion strategy no longer remained an independent predictor of ICU discharge time (p=0.09), however, cardiopulmonary bypass time (p=0.02), age (p=0.012) and emergent surgery (p=0.02) were.

CONCLUSIONS

A WBP strategy during aortic arch reconstruction with MHCA may be associated with more rapid normalization of metabolic parameters and reduced ICU length of stay compared to using ACP alone. Further evaluation with a randomized trial is warranted.

Axillary versus innominate artery cannulation for antegrade cerebral perfusion in aortic surgery: design of the Aortic Surgery Cerebral Protection Evaluation (ACE) CardioLink-3 randomised trial

INTRODUCTION

Neurological injury remains the major cause of morbidity and mortality following open aortic arch repair. Systemic hypothermia along with antegrade cerebral perfusion (ACP) is the accepted cerebral protection approach, with axillary artery cannulation being the most common technique used to establish ACP. More recently, innominate artery cannulation has been shown to be a safe and efficacious method for establishing ACP. Inasmuch as there is a lack of high-quality data comparing axillary and innominate artery ACP, we have designed a randomised, multi-centre clinical trial to compare both cerebral perfusion strategies with regards to brain morphological injury using diffusion-weighted MRI (DW-MRI).

METHODS AND ANALYSIS

110 patients undergoing elective aortic surgery with repair of the proximal arch requiring an open distal anastamosis will be randomised to either the innominate artery or the axillary artery cannulation strategy for establishing unilateral ACP during systemic circulatory arrest with moderate levels of hypothermia. The primary safety endpoint of this trial is the proportion of patients with new radiologically significant ischaemic lesions found on postoperative DW-MRI compared with preoperative DW-MRI. The primary efficacy endpoint of this trial is the difference in total operative time between the innominate artery and the axillary artery cannulation group.

ETHICS AND DISSEMINATION

The study protocol and consent forms have been approved by the participating local research ethics boards. Publication of the study results is anticipated in 2018 or 2019. If this study shows that the innominate artery cannulation technique is non-inferior to the axillary artery cannulation technique with regards to brain morphological injury, it will establish the innominate artery cannulation technique as a safe and potentially more efficient method of antegrade cerebral perfusion in aortic surgery.

TRIAL REGISTRATION NUMBER

NCT02554032.

A Clinical Protocol for Goal Directed Cerebral Perfusion during Aortic Arch Surgery

OBJECTIVE

The optimal strategy to deliver antegrade cerebral perfusion for cerebral protection during hypothermic circulatory arrest has not been established. The purpose of this review was to present our current clinical protocol utilizing selective antegrade cerebral perfusion during aortic arch surgery and to compare it to other published experience.

CLINICAL PROTOCOL

Since 2013, our clinical protocol for aortic arch surgery has evolved to using selective antegrade cerebral perfusion via the innominate artery, moderate hypothermia, and ancillary strategies such as goal-directed perfusion (GDP). Other published techniques favored antegrade cerebral perfusion but were limited by smaller cannulae, multiple cannulation sites, and lower cooling temperatures.

CONCLUSION

Our clinical protocol may offer higher flow rates, avoid complications associated with additional cannulae, and provide an easy setup for dual arterial perfusion. Additionally, GDP has enhanced our understanding of metabolic physiology and may facilitate the development of a better cerebral protection strategy.