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

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.

Comparison of Single Axillary vs. Dual Arterial Cannulation for Acute Type a Aortic Dissection: A Propensity Score Matching Analysis

Background

The optimal arterial cannulation site for acute aortic dissection repair is unclear, especially for complex arch surgery. Axillary artery cannulation is widely accepted but adding femoral artery cannulation to it was considered to potentially improve perfusion and early outcomes. To clarify this point, a comparison of perioperative outcomes for these two different cannulation strategies was conducted regarding the pathological features of dissection.

Methods

From January 2010 to December 2019, 927 consecutive patients underwent a total arch replacement combined with frozen elephant trunk for acute type A aortic dissection. The data, including detailed pathological features, were retrospectively collected and analyzed. Propensity score matching and multivariate logistic regression analysis were used for adjusting confounders that are potentially related to the outcome.

Results

A total of 523 patients (56.3%) accepted a dual arterial cannulation (DAC group), and 406 patients (43.7%) received a single axillary artery cannulation (SAC group). In total, 388 pairs of patients were well-matched. Whether before or after adjusting the preoperative characteristics by matching, there were no significant differences in operative mortality (6.7 vs. 5.4%, P = 0.420 before matching; 5.4 vs. 5.4%, P = 1 after matching), stroke (6.7 vs. 5.4%, P = 0.420 before matching; 6.4 vs. 5.2%, P = 0.435 after matching), spinal cord injury (5 vs. 5.7%, P = 0.640 before matching; 5.4 vs. 5.7%, P = 1. After matching), and acute renal failure requiring dialysis (13.8 vs. 9.6%, P =0.050 before matching; 12.6 vs. 9.5%, P = 0.174) between the two groups. Dual arterial cannulation was not an independent protective factor of operative mortality (odds ratio [OR] 1.01, 95% confidence interval [CI] 0.55–1.86), stroke (OR 1.17, 95% CI 0.65–2.11), spinal cord injury (OR 1.17, 95% CI 0.65–2.11), and acute renal failure requiring continuous renal replacement therapy (CRRT) (OR 1.24, 95% CI 0.78–1.97) after adjusting for confounding factors by multivariable logistic regression analysis. In the subgroup analysis, no advantage of dual arterial cannulation was found for a particular population.

Conclusions

Single axillary artery cannulation was competent in the complex arch repair for acute aortic dissection, presenting with a satisfactory result as dual arterial cannulation. Adding femoral artery cannulation was necessary when a sufficient flow volume could not be achieved by axillary artery cannulation or when a lower limb malperfusion existed.

Surgical strategies for severely atherosclerotic (porcelain) aorta during coronary artery bypass grafting

Porcelain aorta (PA) is an asymptomatic atherosclerotic disease, characterized by circumferential calcification throughout the whole perimeter of the aorta. It is seen in 2% to 9.3% of patients undergoing elective coronary artery bypass grafting (CABG) and makes manipulation of the ascending aorta impossible. It has been clearly shown that most emboli seen and detected during the CABG procedure occur during aortic cross-clamping and aortic side-clamping. Manipulation of porcelain or a severely atherosclerotic aorta increases the risk of perioperative stroke. The incidence of stroke after CABG is between 0.48% and 2.9%, and the risk is correlated with the extent and severity of the atherosclerotic disease. A conventional CABG procedure involves successive steps that include cannulation of the ascending aorta, application of a cross-clamp to the aorta, and partial clamping of the aorta to create the proximal anastomosis. Therefore in procedures that involve cannulation, clamping, or proximal anastomosis, and where aortic manipulation is inevitable, preassessment of the atherosclerotic aortic plaques is crucial. Although many surgeons still rely on intraoperative manual aortic palpation, this approach has very low sensitivity and underestimates the severity of the atherosclerotic illness. Imaging methods including preoperative computed tomography or intraoperative epiaortic ultrasonography enable modification of the surgical technique according to the severity of atherosclerosis. Various surgical techniques have been described to reduce the risk of atheroembolism that may lead to cerebrovascular events in patients with severely atherosclerotic ascending aorta. Anaortic or “no-touch” techniques that do not utilize aortic manipulation may significantly decrease the development of neurological complications by avoiding aortic maneuvers known to cause emboli. In cases where severe atherosclerotic disease or other factors preclude safe use of the ascending aorta, modifications in the surgical techniques, such as switching to different cannulation sites including the axillary/subclavian, femoral and innominate arteries, or using hypothermic ventricular fibrillation and in-situ pedicled arterial grafts, or performing proximal anastomoses at alternative anatomical locations will enable CABG operations to be performed safely with low morbidity and mortality rates in patients with porcelain aortas.

Femoral versus axillary cannulation in acute type A aortic dissections: A meta-analysis

OBJECTIVE

There has been a growing interest in antegrade cannulation techniques in type A aortic dissection surgery. Axillary cannulation has previously been reported to provide better outcomes in terms of short-term mortality and neurological event. Consensus regarding the best cannulation strategy still remains controversial.

METHOD

The MEDLINE and EMBASE databases were conducted up until October 3, 2020. Data regarding mortality, stroke, reoperation for bleeding and length of hospital stay, wound infection and cardiopulmonary bypass time were extracted and submitted to a meta-analysis using random-effects modelling and the I² -test for heterogeneity. Fourteen retrospective observational studies were included, enrolling a total of 2621 patients.

RESULTS

There were a total of 2621 patients (1327 axillary cannulation and 874 femoral cannulation). Axillary cannulation was associated with reduced short term mortality (pooled odds ratio [OR] = +0.42, 95% confidence interval [CI] = +0.25 to +0.70; p = .0009) compared to femoral cannulation. Axillary cannulation was also associated with a lower incidence of neurological events (pooled OR = +0.63, 95% CI = +0.42 to +0.94; p = .02).

CONCLUSION

Our meta-analyses suggests that axillary cannulation has superior outcomes in terms of mortality and stroke following emergency surgery for type A aortic dissection. However, the lack of high quality randomized controlled trials does not make this recommendation generalisable to all units.

Utility of double arterial cannulation for surgical repair of acute type A dissection

OBJECTIVES

Outcomes of planned and unplanned (rescue) double arterial cannulation (DAC) in surgery for acute type A aortic dissection were investigated retrospectively.

METHODS

The study involved 805 patients who were divided into 4 groups according to the cannulation strategy: single cannulation of the femoral artery (n = 338), axillary artery (n = 256), left ventricular apex (n = 52) or ascending aorta (n = 5) (total, n = 57), and DAC (n = 154). Patients who underwent DAC were divided between planned (n = 132) and rescue (n = 22) usage. Characteristics and outcomes were compared between groups. Both unmatched and propensity score-matched analyses were performed.

RESULTS

Shock (39%, 19%, 33% and 14%, in the femoral artery, axillary artery, left ventricular apex/ascending aorta and DAC, respectively) and leg malperfusion (5%, 16%, 16% and 26%, respectively) differed significantly (P < 0.001), but in-hospital mortality did not (9%, 8%, 18% and 7%, respectively; P = 0.096). The 5-year survival rates were 79.4%, 79.7%, 78.6% and 82.2%, respectively. Propensity score-matched analysis showed no statistically significant differences in in-hospital mortality rates (10%, 12%, 14% and 9%, respectively; P = 0.78) and 5-year survival rates (78.4%, 72.3%, 82.3% and 78.0%, respectively). The leading vessel combination and indications for planned and rescue DAC were the femoral and axillary arteries (98%) and true lumen narrowing and/or leg malperfusion (34%), and the axillary followed by femoral (77%) artery and low cardiopulmonary bypass flow (36%). In-hospital mortality in the planned and rescue DAC groups was 7% and 9%, respectively.

CONCLUSIONS

DAC seems effective for both prevention and management of intraoperative malperfusion.

The use of innominate artery cannulation for antegrade cerebral perfusion in aortic dissection

BACKGROUND

Direct cannulation of the innominate artery for selective antegrade cerebral perfusion has been shown to be safe in elective proximal aortic reconstructions. We sought to evaluate the safety of this technique in acute aortic dissection.

METHODS

A multi-institutional retrospective review was undertaken of patients who underwent proximal aortic reconstruction for Stanford type A dissection between 2006 and 2016. Those patients who had direct innominate artery cannulation for selective antegrade cerebral perfusion were selected for analysis.

RESULTS

Seventy-five patients underwent innominate artery cannulation for ACP for Stanford Type A Dissections. Isolated replacement of the ascending aorta was performed in 36 patients (48.0%), concomitant aortic root replacement was required in 35 patients (46.7%), of whom 7 had a valve-sparing aortic root replacement, ascending aorta and arch replacement was required in 4 patients (5%). Other procedures included frozen elephant trunk (n = 11 (14.7%)), coronary artery bypass grafting (n = 20 (26.7%)), and peripheral arterial bypass (n = 4 (5.3%)). Mean hypothermic circulatory arrest time was 19 ± 13 min. Thirty-day mortality was 14.7% (n = 11). Perioperative stroke occurred in 7 patients (9.3%).

CONCLUSIONS

This study is the first comprehensive review of direct innominate artery cannulation through median sternotomy for selective antegrade cerebral perfusion in aortic dissection. Our experience suggests that this strategy is a safe and effective technique compared to other reported methods of cannulation and cerebral protection for delivering selective antegrade cerebral perfusion in these cases.

Repair of Acute Type-A Aortic Dissection in the Present Era: Outcomes and Controversies

Acute Type-A aortic dissection (AAAD) remains a surgical emergency with a relatively high operative mortality despite advances in medical and surgical management over the past three decades. In spite of the severity of disease, there is a paucity of studies reviewing key controversies surrounding AAAD repair and management. A systematic literature search was performed using Cochrane review and PubMed bibliography review. Abstracts were first reviewed for general pertinence and then articles were reviewed in full. Literature review indicates that use of moderate hypothermia and antegrade cerebral perfusion is a safe alternative to deep hypothermia. In hemodynamically stable patients, axillary cannulation may be substituted for femoral cannulation. With regard to the technical aspects of repair, preserving the aortic root whenever possible and performing the distal anastomosis with the open distal technique rather than with the clamp on is the preferred approach. In patients with a patent false lumen, close monitoring is indicated. As demonstrated by the literature, significant improvement of early and late mortality over the past years has occurred in patients presenting with AAAD. Repair of acute Type-A aortic dissection remains a challenge with high operative mortality; however, improvement of surgical techniques and management have resulted in improvement of early and late clinical outcomes.

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.

Role of Moderate Hypothermia and Antegrade Cerebral Perfusion during Repair of Type A Aortic Dissection

The goal of this study was to compare early postoperative outcomes and actuarial survival between patients who underwent repair of acute type A aortic dissection with deep or moderate hypothermia. A total of 132 consecutive patients from a single academic medical center underwent repair of acute type A aortic dissection between January 2000 and June 2014. Of those, 105 patients were repaired under deep hypothermia (< 24 C°), while 27 patients were repaired under moderate hypothermia (≥24 C°). Median ages were 62 years (range: 27-86) and 59 years (range: 35-83) for patients repaired under deep hypothermia compared with patients repaired under moderate hypothermia, respectively ( p  = 0.451). Major morbidity, operative mortality, and 10-year actuarial survival were compared between groups. Operative mortality was 17.1 and 7.4% in the deep and moderate hypothermia groups, respectively ( p  = 0.208). Incidence of permanent stroke was 12.4% in the deep hypothermic circulatory arrest group and 0% in the moderate hypothermia group ( p  = 0.054). Actuarial 5- and 10-year survival demonstrated a trend for lower long-term mortality with moderate hypothermia compared with deep hypothermia (69% 5-year and 54% 10-year for deep hypothermia vs. 79% 5-year and 10-year for moderate hypothermia, log-rank p  = 0.161). Moderate hypothermia is a safe and efficient alternative to deep hypothermia and may have protective benefits. Stroke rate was lower with moderate hypothermia.