Axillary artery cannulation: routine use in ascending aorta and aortic arch replacement

Current review of acute type A aortic dissection in Malaysia

Acute type A aortic dissection (ATAAD) still poses significant challenges and management dilemmas for cardiovascular surgeons worldwide. Despite the continuous improvement in diagnosis and management strategies for ATAAD, clinical outcomes remain poor and the optimal therapy is still debatable especially those with malperfusion syndrome (MPS). This review is based on the current literature and includes the results from the Aortic Registry of National Heart Institute of Malaysia (NHIM) database. It covers different aspects of ATAAD and concentrates on the outcome of surgical repair. The diagnosis is often delayed leading to variable outcomes. High index of suspicion and urgent treatment is required to tackle this dynamic disease which include the variation in presentation and clinical course. Different surgical techniques and perfusion strategies have been described to save patients. Complex techniques such as total arch replacement (TAR) with frozen elephant trunk and valve sparing root surgery may provide long-term benefit in selected patients, but require significant surgical expertise and experience.

Low-flow perfusion technique for shaggy aortic arch

BACKGROUND

The most common complication of thoracic aortic disease with shaggy aorta is cerebral infarction. We have performed "low-flow perfusion" as a method of extracorporeal circulation to prevent cerebral embolism in patients with strong atherosclerotic lesions in the aortic arch.

METHODS

"Low-flow perfusion" is a method in which cardiopulmonary bypass is started by partial blood removal, approaching deep hypothermia while maintaining self-cardiac output. We compared the outcomes of 12 patients who underwent the "low-flow perfusion" method (Group L) with those of 12 who underwent normal extracorporeal circulation (Group N) during aortic arch surgery since 2019.

RESULTS

Group L consisted of 8 males with an average age of 73 years old, and Group N consisted of 6 males with an average age of 73 years old. The average time from the start of cooling to ventricular fibrillation was 9.5 min in Group L and 3.6 min in Group N (p < 0.01). The eardrum temperature when ventricular fibrillation was reached was 28.2 °C in Group L and 32.5 °C in Group N (p = 0.01). A blood flow analysis also revealed low wall shear stress on the lesser curvature of the aortic arch.

CONCLUSION

With this method, the intracranial temperature was sufficiently low at the time of ventricular fibrillation, and there was no need to increase the total pump flow. The low-flow perfusion method can prevent cerebral embolism by preventing atheroma destruction by the blood flow jet while maintaining the self-cardiac output during the cooling process.

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.

Central aortic versus axillary artery cannulation for aortic arch surgery

Objective

Central aortic cannulation for aortic arch surgery has become more popular over the last decade; however, evidence comparing it with axillary artery cannulation remains equivocal. This study compares outcomes of patients who underwent axillary artery and central aortic cannulation for cardiopulmonary bypass during arch surgery.

Methods

A retrospective review of 764 patients who underwent aortic arch surgery at our institution between 2005 and 2020 was performed. The primary outcome was failure to achieve uneventful recovery, defined as having experienced at least 1 of the following: in-hospital mortality, stroke, transient ischemic attack, bleeding requiring reoperation, prolonged ventilation, renal failure, mediastinitis, surgical site infection, and pacemaker or implantable cardiac defibrillator implantation. Propensity score matching was used to account for baseline differences across groups. A subgroup analysis of patients undergoing surgery for aneurysmal disease was performed.

Results

Before matching, the aorta group had more urgent or emergency operations (P = .039), fewer root replacements (P < .001), and more aortic valve replacements (P < .001). After successful matching, there was no difference between the axillary and aorta groups in failure to achieve uneventful recovery, 33% versus 35% (P = .766), in-hospital mortality, 5.3% versus 5.3% (P = 1), or stroke, 8.3% versus 5.3% (P = .264). There were more surgical site infections in the axillary group, 4.8% versus 0.4% (P = .008). Similar results were seen in the aneurysm cohort with no differences in postoperative outcomes between groups.

Conclusions

Aortic cannulation has a safety profile similar to that of axillary arterial cannulation in aortic arch surgery.

Systematic Innominate Artery Cannulation Strategy in Acute Type A Aortic Dissection: Better Perfusion, Better Results

(1) Background: Arterial cannulation in type A acute aortic dissection (TAAAD) is still subject to debate. We describe a systematic approach of using the innominate artery for arterial perfusion (2) Methods: The hospital records of 110 consecutive patients with acute TAAAD operated on between January 2014 and December 2022 were retrospectively analyzed. The effect of the cannulation site on early and late mortality, as well as on cardio-pulmonary perfusion indices (lactate and base excess levels, and cooling and rewarming speed) were investigated. (3) Results: There was a significant difference in early mortality (8.82% vs. 40.79%, p < 0.01) but no difference in long-term survival beyond the first 30 days. Using the innominate artery enabled the use of approximately 20% higher CPB flows (2.73 ± 0.1 vs. 2.42 ± 0.06 L/min/m² BSA, p < 0.01), which resulted in more rapid cooling (1.89 ± 0.77 vs. 3.13 ± 1.62 min/°C/m² BSA, p < 0.01), rewarming (2.84 ± 1.36 vs. 4.22 ± 2.23, p < 0.01), lower mean base excess levels during CPB (-5.01 ± 2.99 mEq/L vs. -6.66 ± 3.37 mEq/L, p = 0.01) and lower lactate levels at the end of the procedure (4.02 ± 2.48 mmol/L vs. 6.63 ± 4.17 mmol/L, p < 0.01). Postoperative permanent neurologic insult (3.12% vs. 20%, p = 0.02) and acute kidney injury (3.12% vs. 32.81%, p < 0.01) were significantly reduced. (4) Conclusions: systematic use of the innominate artery enables better perfusion and superior results in TAAAD repair.

Impact of the Isolated Cerebral Perfusion Technique for Aortic Arch Aneurysm Repair in Patients with a Shaggy Aorta

Objective: Total aortic arch replacement (TAR), particularly in individuals with extensive atherosclerotic alterations, especially shaggy aortas, is more crucial and difficult. The objective of this retrospective investigation was to ascertain if patients with shaggy aortas would respond to modified isolated cerebral perfusion (ICP). Materials and Methods: Between 2015 and 2020, nine individuals with shaggy aortas who received treatment for arch aneurysms were examined. Four and five patients, respectively, who had arch replacement with traditional selective cerebral perfusion (SCP) and modified ICP, were evaluated, and their short- and long-term results were compared. Results: There were no appreciable variations in the postoperative results between patients with traditional SCP and those with modified ICP. Following surgery, one patient developed paraparesis, while two individuals with traditional SCP experienced persistent neurological damage. In patients with modified ICP, there were no postoperative neurological or other problems associated to atherosclerosis; nevertheless, one patient experienced stroke 5 months after surgery. Conclusion: Patients with shaggy aorta may not receive enough brain protection from TAR with standard SCP because single axillary artery perfusion can result in nonphysiological flow and atheroma separation. Even in patients with shaggy aortas, TAR with modified ICP is safe, but late-phase severe adverse cerebrovascular events should be taken into account.

Contemporary utilization of the axillary artery in cardiac surgery

INTRODUCTION

The axillary artery is a reliable inflow vessel when addressing pathology of the aortic root and aortic arch that may preclude standard central cannulation strategies. This narrative review examines the use of the axillary artery in cardiac surgery. Anatomy, indications for use, cannulation strategies, and potential complications will be discussed.

METHODS

A comprehensive review of the current literature was performed using PubMed, Cochrane Review, and authoritative committee guidelines. A narrative review incorporating current available evidence was undertaken.

COMMENT

Use of the axillary artery in select cardiac surgical cases is reliable, reproducible, and may be preferable in certain cases involving ascending aortic pathology, reoperative surgery, porcelain aorta, access for transcatheter valve therapies, and peripheral mechanical circulatory support.

Innominate artery direct cannulation provides brain protection during total arch replacement for acute type A aortic dissection

Background

This study aimed to investigate the safety of direct innominate arterial (IA) cannulation using a pediatric arterial cannula to establish selective antegrade cerebral perfusion (ACP) during total arch replacement (TAR) for acute Stanford type A aortic dissection (ATAAD).

Methods

This retrospective study included patients with ATAAD who underwent TAR with the frozen elephant trunk (FET) technique between October 2020 and November 2021. Patients treated with direct IA cannulation using a pediatric arterial cannula for selective anterograde cerebral perfusion were included in the study.

Results

Of the 29 patients, 24 (82.8%) were male. The average age was 50.9 ± 9.47 years. Proximal repair included aortic root plasty (27 patients, [93.1%]) and Bentall surgery (2 patients, [6.9%]). Perioperative mortality and stroke rates were 3.4% and 6.9%, respectively. The mean lowest core temperature was 23.8 ± 0.74 °C and the mean ACP time was 25 ± 6.4 min. The aortic cross-clamp and cardiopulmonary bypass times were 141 ± 28 and 202 ± 29 min, respectively. There were no cases of IA injuries.

Conclusion

Direct IA cannulation using a pediatric arterial cannula is a simple, safe, and effective technique for establishing ACP during TAR with the FET technique for ATAAD and can avoid the potential complications of axillary artery cannulation.

Comparison of Post-operative Outcomes Between Direct Axillary Artery Cannulation and Side-Graft Axillary Artery Cannulation in Cardiac Surgery: A Systematic Review and Meta-Analysis

Background

There is a growing perception of using axillary artery cannulation to improve operative outcomes in cardiopulmonary bypass surgery. Two techniques, direct cannulation or side-graft cannulation, can be used for axillary artery cannulation, but which technique is better is controversial.

Methods

A meta-analysis of comparative studies reporting operative outcomes using direct cannulation vs. side-graft cannulation was performed. We searched the PubMed, EMbase, Web of Science, and Cochrane Library. Outcomes of interest were neurological dysfunction, cannulation-related complications and early mortality. The fixed effects model was used.

Results

A total of 1,543 patients were included in the final analysis. Direct cannulation was used in 846 patients, and side-graft cannulation was used in 697 patients. Meta-analysis showed a higher occurrence of neurological Complication in direct cannulation group [odds ratio, 1.45, 95% CI (1.00, 2.10), χ² = 4.40, P = 0.05] and a significantly higher incidence of cannulation-related complications in the direct cannulation group [odds ratio, 3.12, 95% CI (1.87, 5.18), χ² = 2.54, P < 0.0001]. The incidence of early mortality did not have a difference [odds ratio, 0.95, 95% CI (0.64, 1.41), χ² = 6.35, P = 0.79].

Conclusions

This study suggests that side-graft axillary artery cannulation is a better strategy as it reduces the incidence of neurological dysfunction and cannulation-related complications.

Systematic Review Registration

https://www.crd.york.ac.uk/PROSPERO/, identifier: CRD42022325456.

Intraoperative nadir hematocrit as a poor outcome predictor after acute type A aortic dissection surgey

Acute type A aortic dissection is a life-threatening disease associated with high morbidity and mortality that requires urgent surgical intervention. Hemodilution is inevitable in cardiac operations performed with cardiopulmonary bypass, which leads to nadir hematocrit levels. Studies have shown that nadir hematocrit levels are associated with poor postoperative outcomes. The management strategy of intraoperative anemia in these operations is still controversial. Should we follow the patients with intraoperative low hematocrit values or should we transfuse them? In addition to intraoperative nadir hematocrit, cannulation strategies play an important role in early postoperative outcomes after aortic dissection surgery.

Direct Axillary Artery Cannulation for Aortic Surgery: Lessons From Contemporary Experiences

BACKGROUND

This study seeks to assess the outcomes of direct axillary artery (AX) cannulation for thoracic aortic surgery.

METHODS

From October 2009 to November 2021 direct AX cannulation was planned in 515 patients for thoracic aortic pathology. An important aspect of our technique is that the cannula is not inserted deeper than 3 cm. AX cannulation-related events included shift of cannulation site from the initial site, vascular injury, and iatrogenic dissection.

RESULTS

Half of the patients had acute type A dissection (ATAD). An angled cannula was used in 442 patients and a straight cannula in 73 patients (14.2%) after August 2020. A previously cannulated AX was reused in 36 patients (7.0%). Mortality and stroke rates were 5.4% (ATAD vs non-ATAD: 8.0% vs 2.8%, P = .008) and 2.7% (ATAD vs non-ATAD: 4.6% vs 0.8%, P = .034), respectively. AX cannulation-related events were observed in 2.7% of patients. There was no difference in the vascular injury rate between ATAD and non-ATAD cases (1.6% vs 0.4%, respectively; P = .385), between different cannula types (angled vs straight: 0.9% vs 1.4%, P = 1.00), or between primary and redo AX cannulation cases (0.8% vs 2.8%, respectively; P = .791). On multidetector computed tomography analysis using automated 3-dimensional images, the mean distance from the thoracoacromial artery to the vertebral artery on the right and left sides was 8.70 cm and 8.69 cm, respectively.

CONCLUSIONS

Direct AX cannulation for thoracic aortic repair is safe and carries a low rate of vascular injury, especially in elective cases. Our direct cannulation technique, which includes not inserting a cannula deeper than 3 cm, seems to be safe in not occluding the vertebral artery.

Direct Innominate Artery Cannulation versus Side Graft for Selective Antegrade Cerebral Perfusion during Aortic Hemiarch Replacement

Background  Selective antegrade cerebral perfusion (SACP) has become our preferred method for cerebral protection during open arch cases. While the initial approach involved sewing a graft to the innominate artery as the arterial cannulation site, our access strategy has since evolved to central aortic cannulation with use of a percutaneous cannula in the innominate for SACP. We hypothesized that SACP delivered via direct innominate cannulation using a 12- or 14-Fr cannula results in equivalent outcomes to cases utilizing a side graft.

Methods  This was a single-center, retrospective analysis of 211 adult patients who underwent elective hemiarch replacement using hypothermic circulatory arrest with SACP via the innominate artery between 2012 and 2020. Urgent and emergent cases were excluded.

Results  A side graft sutured to the innominate was utilized in 81% ( n  = 171) of patients, while direct innominate artery cannulation was performed in 19% ( n  = 40) of patients. Baseline patient characteristics were similar between groups aside from a higher baseline creatinine in the direct cannulation group (1.3 vs. 0.9, p  = 0.032). Patients undergoing direct cannulation demonstrated shorter cardiopulmonary bypass time (132.7 vs. 154.9 minutes, p  = 0.020) and shorter circulatory arrest time (8.1 vs. 10.9 minutes, p  = 0.004). Nadir bladder temperature did not significantly differ between groups (27.2°C for side graft vs. 27.6°C for direct cannulation, p  = 0.088). There were no significant differences in postoperative outcomes.

Conclusion  Direct cannulation of the innominate artery with a 12- or 14-Fr cannula for SACP during hemiarch replacement is a safe alternative to using a sutured side graft. While cardiopulmonary bypass and circulatory arrest times appear improved, this is likely attributable to accumulation of experience and proficiency in technique. However, direct innominate artery cannulation may facilitate quicker completion of these procedures by eliminating the time necessary to suture a graft to the innominate artery.

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.

Direct Axillary Artery Cannulation for Type A Dissection and Impact of Dissected Innominate Artery

BACKGROUND

This study seeks to assess the safety of direct axillary artery (AX) cannulation for acute type A dissection (ATAD) repair, including the impact of innominate artery dissection (IAD).

METHODS

Of 281 consecutive patients who underwent ATAD repair from 2007 to 2020, preoperative computed tomography was available in 200 (IAD: N=101, non-IAD N=99). IAD with compromised true lumen was defined as dissection in which the false lumen was greater than 50% of the IA diameter (N=75/101).

RESULTS

AX cannulation was attempted in 188 patients (94.0%), with a 1.6% vascular injury rate (3 patients; bypass to the distal AX: 2 patients, and local dissection: 1 patient). Most patients (89.5%) underwent hemiarch replacement using deep hypothermic circulatory arrest for the distal repair. Right AX cannulation was used in 80.2% of patients with IAD and in 88.9% without IAD (p=0.075). Patients with IAD had more cerebral (21.8%vs. 5.1%, p=0.001) and arm malperfsion (11.9% vs.4.0%, p=0.075). Operative mortality and stroke were comparable between Non-IAD and IAD groups (8.1% vs. 7.9%, p=1.00 and 4.0% vs. 5.3%, p=0.689). The right AX was successfully used in 77.3% of IAD patients having a compromised true lumen, with comparable hospital outcomes to non-compromised IAD patients. Upper extremity malperfusion, multi-organ malperfusion, low ejection fraction, and female gender were predictors for non-right AX cannulation.

CONCLUSIONS

Routine direct AX cannulation strategy is safe in ATAD repair. Right AX cannulation can be used in most patients with IAD, even with a compromised true lumen, with low mortality, stroke and vascular injury rates.

Directing a dispersion cannula tip toward the aortic root during thoracic aortic arch surgery does not adversely affect cardiac function

INTRODUCTION

Neurologic complications of open thoracic aortic surgery are devastating problems in patients with severely diseased aortas. This study aimed to clarify whether directing the aortic cannula tip toward the aortic root affects the postoperative cardiac function in patients undergoing open thoracic aortic surgery.

METHODS

A total of 16 patients who underwent total or partial arch replacement between January 2014 and April 2019 were enrolled and divided into two groups. Ascending aorta perfusion was performed by placing the cannula tip toward the aortic root (reversed direction group, seven patients) or toward the aortic arch (standard direction group, nine patients). Intraoperative and perioperative data, including mortality, morbidity, and postoperative cardiac function, were compared between the groups.

RESULTS

There were no hospital deaths or stroke events in either group. The aortic cross-clamping time was 102.4 ± 20.3 minutes in the reversed direction group and 87.1 ± 9.9 minutes in the standard direction group (p = 0.049). Furthermore, the intubation time was 28.4 ± 12.9 hours in the reversed direction group and 12.4 ± 6.8 hours in the standard direction group (p = 0.022). Both times were significantly longer in the reverse direction group. Postoperative serum creatine kinase-MB levels were significantly lower in the reversed direction group (6.2 ± 3.3 U/L vs 13.3 ± 4.8 U/L, respectively, p = 0.006). The cardiac output and cardiac index did not significantly differ.

CONCLUSIONS

Directing the aortic cannula tip toward the aortic root does not adversely affect the postoperative cardiac function after aortic arch surgery.

Reoperative Total Arch Repair Using a Trifurcated Graft and Selective Antegrade Cerebral Perfusion

BACKGROUND

This study reviews the outcomes of our reoperative total arch repair (TAR) technique using a trifurcated graft and selective antegrade cerebral perfusion (SACP).

METHODS

Fifty patients underwent reoperative TAR from January 2005 to September 2020, with either a one-stage (N=9), or two-stage repair (N=41). The two-stage technique includes minimal dissection of the mediastinal structures, an arch-first technique using a trifurcated graft, and construction of a classical elephant trunk via a partial transverse incision distally in the old-graft or in the aorta just distal to the old graft.

RESULTS

The median age was 63 years. Chronic dissection was the most frequent indication (88%) and 98% had undergone a previous proximal aortic repair at a median interval of 3.0 years. The median cardiopulmonary bypass, myocardial ischemic, SACP, and lower body circulatory arrest times were 226, 103, 97, and 98 minutes, respectively. The minimum nasopharyngeal and bladder temperature were 16.5 °C, and 20.0 °C. Operative mortality was 2% and the incidence of stroke, and spinal cord injury (SCI) were 2%, and 0%. Stage II repair was performed in 37 patients (open: 33 patients, endovascular: 4 patients), with two mortalities and no SCI. The median duration between stage I and II was 63 days. Survival and aortic event free rates at 3 years were 88.4 ±4.9%, and 89.8 ±5.0%.

CONCLUSIONS

We report a reoperative TAR technique that minimizes dissection of the cardiac structures, simplifies the distal anastomosis, and protects vital organs, such as the brain, heart, and spinal cord.

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.

Iatrogenic Aortic Dissection Associated With Cardiac Surgery: A Narrative Review

Iatrogenic aortic dissection (iAD) is a relatively rare but a life-threatening complication associated with cardiac surgery. All members of the team caring for cardiac surgical patients (surgeons, perfusionists, and anesthesiologists) must be familiar with this complication to minimize its incidence and improve outcome. The present narrative review focuses on iAD occurring intraoperatively and during the early postoperative period (within 1 month) of cardiac surgery. The review also addresses iAD that occurs late (beyond 1 month) after cardiac surgery and iAD associated with other procedures. iAD occurs in about 0.06% of cases when the ascending aorta is the site of arterial cannulation, in about 0.6% when the femoral or iliac arteries are used, and in about 0.5% when the axillary or subclavian arteries are used. Mortality is estimated to be 30% but is more than double if not recognized until the postoperative period. Site of origin of dissection is most commonly the arterial inflow cannula (∼33%). Other common sites are the aortic cross-clamp or partial occlusion clamp (∼29%) and the proximal saphenous vein anastomosis site (14%). Sixty percent of cases occur during coronary artery bypass graft (CABG) surgery and 17% during aortic valve surgery with or without CABG. iAD may be somewhat less common in off-pump versus on-pump CABG but is still not very rare. Risk factors, presentation, diagnosis, and management are reviewed in detail as is the key role of the use of echocardiography in the early diagnosis of iAD and for guiding its management.

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.

Acute type A aortic dissection - a review

Acute type A aortic dissection (ATAAD) is still one of the most challenging diseases that cardiac surgeons encounter. This review is based on the current literature and includes the results from the Nordic Consortium for Acute Type-A Aortic Dissection (NORCAAD) database. It covers different aspects of ATAAD and concentrates on the outcome of surgical repair. The diagnosis is occasionally delayed, and ATAAD is usually lethal if prompt repair is not performed. The dynamic nature of the disease, the variation in presentation and clinical course, and the urgency of treatment require significant attentiveness. Many surgical techniques and perfusion strategies of varying complexity have been described, ranging from simple interposition graft to total arch replacement with frozen elephant trunk and valve-sparing root reconstruction. Although more complex techniques may provide long-term benefit in selected patients, they require significant surgical expertise and experience. Short-term survival is first priority so an expedited operation that fits in with the surgeon's level of expertise is in most cases appropriate.

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.

Samurai cannulation (direct true-lumen cannulation) for acute Stanford Type A aortic dissection

OBJECTIVES

In this study, we investigated early outcomes of patients who underwent surgical aortic repair for acute Stanford Type A aortic dissection at the Kitasato University Hospital and compared the results of Samurai cannulation (direct true-lumen cannulation) with other cannulation options.

METHODS

Inpatient and outpatient records were retrospectively reviewed.

RESULTS

Among the 100 patients who were operated on for acute Type A aortic dissection between April 2011 and April 2017, sole Samurai cannulation was used in 61 patients (Group S) and other cannulation options were used in the remaining 39 patients (Group O). No significant difference was observed in preoperative demographics between the groups. True-lumen cannulation was successful in all Group S patients, whereas 3 cannulation-related complications were observed in Group O patients. In Group S, the 30-day and in-hospital mortality occurred in 3 (5%) and 4 (7%) patients, respectively, and in Group O, these occurred in 3 (8%), and 6 (15%) patients, respectively. Four patients in each group (7% and 10%) experienced disabling or fatal strokes. Early mortality or stroke rate between the groups were not significantly different. During follow-up, there was no statistically significant difference between the groups in terms of survival, freedom from aorta-related death or freedom from aortic events.

CONCLUSIONS

Early outcomes of the initial series of surgery for Stanford Type A aortic dissection with Samurai cannulation was favourable with acceptable mortality and stroke rates without cannulation-related complications. Samurai cannulation represents an easy, safe and reasonable option for cardiopulmonary bypass in surgery for acute Stanford Type A aortic dissection.

Pectoral Muscle Atrophy After Axillary Artery Cannulation for Aortic Arch Surgery

To investigate postoperative pectoral atrophy in 141 patients undergoing aortic arch surgery involving bilateral axillary artery cannulations with side grafts. The depth from the skin to the axillary artery surrounding the thoracoacromial artery (zone 1), and the thicknesses of pectoralis major (zone 2) and pectoralis minor (zone 3) were measured by computed tomography before surgery, at 1 and 6 months after surgery, and at the most recent follow-up assessment (PostT2) (mean = 41 months, range 11-75 months). Based on the median value (47.4 mm) of zone 1, the preoperative pectoral thickness was categorized into 2 groups: pectoral thickness >47.4 mm (thick group) and ≤47.4 mm (thin group). Mean changes in the pectoral thickness from baseline were evaluated using the longitudinal mixed-effects model. Forty-three of 110 patients underwent total arch replacements and extra-anatomical bypasses for left subclavian artery anastomoses. In 3 patients, axillary artery grafts became infected. There was no obvious harm associated with muscle wasting. Mean changes from baseline in zones 1, 2, and 3 showed significant declines at PostT2 (-13.40 ± 9.73 mm [P < 0.0001], -7.00 ± 5.23 mm [P < 0.0001], and -7.23 ± 6.42 mm [P < 0.0001], respectively). In the thick group, the progression of pectoral atrophy in zones 1 and 3 was significantly more than that of the thin group (P < 0.0001 for both zones). Postoperative pectoral atrophy progressed rapidly. The preoperative pectoral size might be of no use in the prevention of pectoral atrophy. Further investigation to prevent the pectoral atrophy is needed.

Predictors of Outcomes after Correction of Acute Type A Aortic Dissection under Moderate Hypothermic Circulatory Arrest and Antegrade Cerebral Perfusion

Introduction

Hypothermic circulatory arrest is widely used for correction of acute type A aortic dissection pathology. We present our experience of 45 consecutive patients operated in our unit with bilateral antegrade cerebral perfusion and moderate hypothermic circulatory arrest.

Methods

Between January 2011 and April 2015, 45 consecutive patients were admitted for acute type A aortic dissection and operated emergently under moderate hypothermic circulatory arrest and bilateral antegrade cerebral perfusion.

Results

Mean age was 58±11.4 years old. Median circulatory arrest time was 41.5 (30-54) minutes while the 30-day mortality and postoperative permanent neurological deficits rates were 6.7% and 13.3%, respectively. Unadjusted analysis revealed that the factors associated with 30-day mortality were: preoperative hemodynamic instability (OR: 14.8, 95% CI: 2.41, 90.6, P=0.004); and postoperative requirement for open sternum management (OR: 5.0, 95% CI: 1.041, 24.02, P=0.044) while preoperative hemodynamic instability (OR: 8.8, 95% CI: 1.41, 54.9, P=0.02) and postoperative sepsis or multiple organ dysfunction (OR: 13.6, 95% CI: 2.1, 89.9, P=0.007) were correlated with neurological dysfunction. By multivariable logistic regression analysis, postoperative sepsis and multiple organ dysfunction independently predicted (OR: 15.9, 95% CI: 1.05, 96.4, P=0.045) the incidence of severe postoperative neurological complication. During median follow-up of 6 (2-12) months, the survival rate was 86.7%.

Conclusion

Bilateral antegrade cerebral perfusion and direct carotid perfusion for cardiopulmonary bypass, in the surgical treatment for correction of acute aortic dissection type A, is a valuable technique with low 30-day mortality rate. However, postoperative severe neurological dysfunctions remain an issue that warrants further research.

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.

Neuroprotective Strategies in Repair and Replacement of the Aortic Arch

Aortic arch surgery is a technical challenge, and cerebral protection during distal anastomosis is a continued topic of controversy and discussion. The physiologic effects of hypothermic arrest and adjunctive cerebral perfusion have yet to be fully defined, and the optimal strategies are still undetermined. This review highlights the historical context, physiological rationale, and clinical efficacy of various neuroprotective strategies during arch operations.

Left Axillary Artery Cannulation Facilitates Reoperative Total Aortic Arch Replacement

Total aortic arch replacement remains a technically formidable procedure, particularly in patients with previous proximal aortic dissection repair. Our case discussion highlights a useful strategy for extracorporeal support and circulation management to facilitate total arch reconstruction in the reoperative setting, based on cannulation of the left axillary artery. Our preference is to use a left axillary artery approach to initiate cardiopulmonary bypass and to ultimately revascularize the left arm via an extra-anatomic graft. Our technique, as described, affords the option to initiate cardiopulmonary bypass before sternal re-entry, it reduces the risk of embolic complications and possible stroke, and it directly facilitates simple extra-anatomic debranching of the left subclavian artery, resulting in easier arch and great vessel reconstruction within the chest.

Triple ultrasonography for iatrogenic acute aortic dissection caused by axillary arterial perfusion

Iatrogenic aortic dissection caused by axillary arterial cannulation or perfusion becomes a fatal complication of cardiopulmonary bypass when surgeons do not recognize it in the surgical field of view immediately during surgery. Therefore, we routinely monitor the aorta using 'triple ultrasonography' during cardiovascular surgery. An 85-year-old woman underwent partial arch replacement for chronic type A aortic dissection. During cardiopulmonary bypass, acute aortic dissection was observed in the aortic arch from the right axillary artery on real-time transoesophageal echocardiography. Epiaortic and neck surface ultrasonography detected malperfusion of the carotid artery. During femoral arterial perfusion, the patient was rescued with partial aortic replacement. Axillary artery cannulation is useful for cardiopulmonary bypass but confers a risk of iatrogenic aortic dissection that cannot be confirmed by surgeons surgically. The transoesophageal echocardiography can guard the aorta while systemic perfusion is initiated. Furthermore, epiaortic and neck surface echography can be incorporated to transoesophageal echocardiography. Triple ultrasonography allows for the detection of iatrogenic aortic dissection.

Fenestrated TEVAR Using a Guidewire Fixator for Anchoring in Aortic Arch Target Vessels

Purpose: To report a new facilitated method for securing target vessel access during single fenestrated and branched thoracic endovascular repair using a guidewire fixator. Technique: The Liungman Guidewire Fixator (LGF) includes a 0.035-inch guidewire that is fitted with a stopper close to the distal end and a self-expanding anchoring element that is freely movable over the guidewire to the point of the stopper. The technique of using a LGF for anchoring in a target vessel is described in a 75-year-old woman with a 53-mm saccular arch aneurysm. She was treated with a fenestrated Zenith stent-graft that had a catheter-preloaded fenestration for the left subclavian artery (LSA) and a scallop for the left common carotid artery. To avoid through-and-through wire and brachial access, the LGF was used to secure the guidewire in the LSA during stent-graft deployment. Conclusion: The use of an LGF for anchoring in the target LSA during fenestrated arch endografting was feasible and safe.

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.

True Lumen Perfusion Technique for Extensive Aortic Dissections Involving the Neck and Femoral Vessels

Cannulation and perfusion in extensive aortic dissection involving the neck and femoral vessels is challenging in view of false lumen cannulation and attendant malperfusion syndromes. Although a number of methods have been described, our technique of cannulation and perfusion through right atrial-to-left atrial bypass and innominate artery transection ensures adequate brain perfusion and visceral organ true lumen perfusion during the entire duration of cardiopulmonary bypass. This procedure can be applied to all varieties of extensive type A aortic dissections involving the neck and femoral vessels. A step-by-step of how to do it has been described.

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.

Cannulation-Related Complications on Veno-Arterial Extracorporeal Membrane Oxygenation: Prevalence and Effect on Mortality

Cannulation-related complications are a known source of morbidity in patients supported on veno-arterial extracorporeal membrane oxygenation (VA-ECMO). Despite its prevalence, little is known regarding the outcomes of patients who suffer such complications. This is a single institution review of cannulation-related complications and its effect on mortality in patients supported on VA-ECMO from January 2010-2015 using three cannulation strategies: axillary, femoral, and central. Complications were defined as advanced if they required major interventions (fasciotomy, amputation, site conversion). Patients were divided into two groups (complication present vs. not present) and Kaplan-Meier analysis was performed to determine any differences in their survival distributions. There were 103 patients supported on VA-ECMO: 41 (40%), 36 (35%), and 26 (25%) were cannulated via axillary, femoral, and central access, respectively. Cannulation-related complications occurred in 33 (32%) patients and this did not differ significantly between either axillary (34%), femoral (36%), or central (23%) strategies (P = 0.52). The most common complications encountered were hemorrhage and limb ischemia in 19 (18%) and 11 (11%) patients. Hemorrhagic complications did not differ between groups (P = 0.37), while limb ischemia and hyperperfusion were significantly associated with femoral and axillary cannulation, at a rate of 25% (P < 0.01) and 15% (P = 0.01), respectively. There was no difference in the incidence of advanced complications between cannulation groups: axillary (12%) vs. femoral (14%) vs. central (8%; P = 0.75). In addition, no increase in mortality was noted in patients who developed a cannulation-related complication by Kaplan-Meier estimates (P = 0.37). Cannulation-related complications affect a significant proportion of patients supported on VA-ECMO but do not differ in incidence between different cannulation strategies and do not affect patient mortality. Improved efforts at preventing these complications need to be developed to avoid the additional morbidity in an already critical patient population.

Differential aspects of ascending thoracic aortic dissection and its treatment: the North American experience

Acute type A aortic dissection is a deadly disease with significant morbidity and mortality. We describe the differential aspects of the disease and the North American experience with its treatment.

Axillary Versus Femoral Arterial Cannulation During Repair of Type A Aortic Dissection?: An Old Problem Seeking New Solutions

BACKGROUND

The goal of this study was to compare early postoperative outcomes and actuarial-free survival between patients who underwent repair of acute Type A aortic dissection with axillary or femoral artery cannulation.

METHODS

A total of 305 patients from five academic medical centers underwent acute Type A aortic dissection repair via axillary (n = 107) or femoral (n = 198) artery cannulation between January 2000 and December 2010. Major morbidity, operative mortality, and 5-year actuarial survival were compared between groups. Multivariate logistic regression was used to determine predictors of operative mortality, and Cox regression hazard ratios were calculated to determine predictors of long-term mortality.

RESULTS

Operative mortality was not influenced by cannulation site (16% for axillary cannulation vs. 19% for femoral cannulation, p = 0.64). In multivariate logistic regression analysis, hemodynamic instability (p < 0.001) and prolonged cardiopulmonary bypass time (>200 min; p = 0.05) emerged as independent predictors of operative mortality. Stroke rates were comparable between the two techniques (14% for axillary and 17% for femoral cannulation, p = 0.52). Five-year actuarial survival was comparable between the groups (55.1% for axillary and 65.7% for femoral cannulation, p = 0.36). In Cox regression analysis, predictors of long-term mortality were: age (p < 0.001), stroke (p < 0.001), prolonged cardiopulmonary bypass time (p = 0.001), hemodynamic instability (p = 0.002), and renal failure (p = 0.001).

CONCLUSIONS

The outcomes of femoral versus axillary arterial cannulation in patients with acute Type A aortic dissection are comparable. The choice of arterial cannulation site should be individualized based on different patient risk profiles.

Contemporary insights into the management of type A aortic dissection

INTRODUCTION

Acute Type A Dissection remains a surgical emergency with a relatively high operative mortality despite advances in cardiac surgical techniques and medical management over the past thirty years.

AREAS COVERED

In this presentation we will discuss the issues surrounding diagnosis, triage, surgical treatment and perioperative medical management as well as long term surveillance of patients suffering from Acute Type A Dissection and present the literature that supports our management strategies. Expert commentary: The ultimate goal of surgical intervention for patients with Type A Acute Aortic Dissection is an alive patient. A more complicated operation which addresses the root and arch and potentially reduces late complications should be approached with caution since it may increase the operative mortality of the procedure itself. With the recent evolution in endovascular techniques, there is hope that later complications can be reduced without increasing the risk of the primary operation. It remains to be seen whether the improved distal aortic remodeling afforded by a combined open/endovascular approach to Acute Type A Dissection will lead to decreased need for aortic reinterventions and overall long term complications of a residual descending thoracic chronic dissection.