Axillary cannulation significantly improves survival and neurologic outcome after atherosclerotic aneurysm repair of the aortic root and ascending aorta

Hypothermic Ventricular Fibrillation in Redo Minimally Invasive Mitral Valve Surgery: A Promising Solution for a Surgical Challenge

Background: Minimally invasive mitral valve surgery (MIMVS) is a treatment for severe mitral valve pathologies. In redo cases, especially after coronary artery bypass grafting (CABG) surgery with patent mammary bypass grafts, establishing aortic clamping followed by antegrade cardioplegia application might be challenging. Here, we present the outcome of hypothermic ventricular fibrillation as an alternative to conventional cardioprotection. Methods: Patients who underwent MIMVS either received hypothermic ventricular fibrillation (study group, n = 48) or antegrade cardioprotection (control group, n = 840) and were observed for 30 postoperative days. Data were retrospectively analyzed and collected from January 2011 until December 2022. Results: Patients in the study group had a higher preoperative prevalence of renal insufficiency (p = 0.001), extracardiac arteriopathy (p = 0.001), insulin-dependent diabetes mellitus (p = 0.001) and chronic lung disease (p = 0.036). Furthermore, they had a longer surgery time and a lower repair rate (p < 0.001). No difference, however, was seen in postoperative incidences of stroke (p = 0.26), myocardial infarction (p = 1) and mitral valve re-operation (p = 1) as well as 30-day mortality (p = 0.1) and postoperative mitral valve insufficiency or stenosis. Conclusions: The patients who underwent redo MIMVS with hypothermic ventricular fibrillation did not have worse outcomes or more serious adverse events compared to the patients who received routine conventional cardioprotection. Therefore, the use of hypothermic ventricular fibrillation appears to be a promising cardioprotective technique in this challenging patient population requiring redo MIMVS.

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.

Axillary vs Femoral Arterial Cannulation in Acute Type A Dissection: International Multicenter Data

BACKGROUND

Cannulation strategy in acute type A dissection (ATAD) varies widely without known gold standards. This study compared ATAD outcomes of axillary vs femoral artery cannulation in a large cohort from the International Registry of Acute Aortic Dissection (IRAD).

METHODS

The study retrospectively reviewed 2145 patients from the IRAD Interventional Cohort (1996-2021) who underwent ATAD repair with axillary or femoral cannulation (axillary group: n = 1106 [52%]; femoral group: n = 1039 [48%]). End points included the following: early mortality; neurologic, respiratory, and renal complications; malperfusion; and tamponade. All outcomes are presented as axillary with respect to femoral.

RESULTS

The proportion of patients younger than 70 years in both groups was similar (n = 1577 [74%]), as were bicuspid aortic valve, Marfan syndrome, and previous dissection. Patients with femoral cannulation had slightly more aortic insufficiency (408 [55%] vs 429 [60%]; P = .058) and coronary involvement (48 [8%] vs 70 [13%]; P = .022]. Patients with axillary cannulation underwent more total aortic arch (156 [15%] vs 106 [11%]; P = .02) and valve-sparing root replacements (220 [22%] vs 112 [12%]; P < .001). More patients with femoral cannulation underwent commissural resuspension (269 [30.9%] vs 324 [35.3%]; P = .05). Valve replacement rates were not different. The mean duration of cardiopulmonary bypass was longer in the femoral group (190 [149-237] minutes vs 196 [159-247] minutes; P = .037). In-hospital mortality was similar between the axillary (n = 165 [15%]) and femoral (n = 149 [14%]) groups (P = .7). Furthermore, there were no differences in stroke, visceral ischemia, tamponade, respiratory insufficiency, coma, or spinal cord ischemia.

CONCLUSIONS

Axillary cannulation is associated with a more stable ATAD presentation, but it is a more extensive intervention compared with femoral cannulation. Both procedures have equivalent early mortality, stroke, tamponade, and malperfusion outcomes after statistical adjustment.

Central versus peripheral cannulation for acute type A aortic dissection: A meta-analysis of over 14,000 patients

OBJECTIVE

The optimal cannulation strategy for patients with acute type A aortic dissections (ATAAD) is unclear.

METHODS

A systematic search was performed to identify all studies comparing aortic and non-aortic cannulation in patients undergoing ATAAD repair. The primary endpoint was overall survival. The secondary endpoints were operative mortality, postoperative stroke, renal failure, renal replacement therapy, paraplegia, and mesenteric ischemia. Pooled meta-analyses with aggregated and reconstructed time-to-event data were performed.

RESULTS

Twenty-three studies were included (aortic: 3904; non-aortic: 10,719). Ten-year overall survival was 61.1 ​% and 58.4 ​% for aortic and non-aortic cannulation, respectively (HR 1.07; 95 ​% CI 0.92-1.25; p ​= ​0.38). No statistically significant difference was observed for operative mortality (p ​= ​0.10), stroke (p ​= ​0.89), renal failure (p ​= ​0.83), or renal replacement therapy (p ​= ​0.77).

CONCLUSION

Patients undergoing surgery for ATAAD can undergo aortic cannulation with similar outcomes to those who undergo non-aortic cannulation.

Aortic versus axillary cannulation in acute type A aortic dissection repair: A meta-analysis

BACKGROUND

Research comparing the effectiveness of central aortic cannulation to axillary artery cannulation in repairing acute type A aortic dissection is limited and controversial. This meta-analysis aimed to compare early outcomes of central aortic cannulation versus axillary artery cannulation for surgery for acute aortic dissection type A.

METHODS

A comprehensive systematic search was conducted across PubMed/MEDLINE, Scopus, and the Cochrane Central Register of Controlled Trials up to September 1, 2023. The primary endpoints were operative mortality and incidence of postoperative stroke. Secondary endpoints encompassed cardiopulmonary bypass time, myocardial ischemic time, hypothermic circulatory arrest time, postoperative temporary neurological dysfunction, combination of stroke and temporary neurological dysfunction, as well as the need for reexploration for bleeding, renal replacement therapy, and tracheotomy. A random-effect model was utilized to calculate the pooled effect size.

RESULTS

Eleven studies met our eligibility criteria, enrolling a total of 7204 patients (2760 underwent aortic cannulation and 4444 underwent axillary cannulation). The operative mortality and incidence of postoperative stroke did not show statistical differences between the two groups, with a pooled odds ratio of 1.07 (95% confidence interval: 0.73-1.55) and 1.17 (0.95-1.42), respectively. Similarly, none of the secondary endpoints exhibited significant statistical differences between the two groups.

CONCLUSIONS

Aortic cannulation can be a viable alternative to axillary artery cannulation for repair of acute aortic dissection type A, as both approaches present similar early clinical outcomes.

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.

Tips and tricks in redo aortic surgery

Redo aortic surgery is challenging, and the operative risk is higher than that in primary aortic surgery. Preoperative imaging is a crucial guide for a safe re-entry. Scrutinized preparing in cannulation and organ protection strategies have affected surgical outcomes. With comprehensive planning and meticulously executed surgery, mortality and morbidity can be acceptable.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-021-01322-x.

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.

Contemporary Neuroprotection Strategies during Cardiac Surgery: State of the Art Review

Open-heart surgery is the leading cause of neuronal injury in the perioperative state, with some patients complicating with cerebrovascular accidents and delirium. Neurological fallout places an immense burden on the psychological well-being of the person affected, their family, and the healthcare system. Several randomised control trials (RCTs) have attempted to identify therapeutic and interventional strategies that reduce the morbidity and mortality rate in patients that experience perioperative neurological complications. However, there is still no consensus on the best strategy that yields improved patient outcomes, such that standardised neuroprotection protocols do not exist in a significant number of anaesthesia departments. This review aims to discuss contemporary evidence for preventing and managing risk factors for neuronal injury, mechanisms of injury, and neuroprotection interventions that lead to improved patient outcomes. Furthermore, a summary of existing RCTs and large observational studies are examined to determine which strategies are supported by science and which lack definitive evidence. We have established that the overall evidence for pharmacological neuroprotection is weak. Most neuroprotective strategies are based on animal studies, which cannot be fully extrapolated to the human population, and there is still no consensus on the optimal neuroprotective strategies for patients undergoing cardiac surgery. Large multicenter studies using universal standardised neurological fallout definitions are still required to evaluate the beneficial effects of the existing neuroprotective techniques.

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.

Intimal aortic atherosclerosis in cardiac surgery: surgical strategies to prevent embolic stroke

 

OBJECTIVES

Although the incidence of perioperative stroke after cardiac surgery gradually decreased over the last decades, there is much variation between centres. This review aimed to create a concise overview of the evidence on possible surgical strategies to prevent embolic stroke in patients with intimal aortic atherosclerosis.

METHODS

The PubMed and EMBASE databases were searched for studies on surgical management of aortic atherosclerosis and the association with perioperative stroke in cardiac surgery, including specific searches on the most common types of surgery. Articles were screened with emphasis on studies comparing multiple strategies and studies reporting on the patients’ severity of aortic atherosclerosis. The main findings were summarized in a figure, with a grade of the corresponding level of evidence.

RESULTS

Regarding embolic stroke risk, aortic atherosclerosis of the tunica intima is most relevant. Although several strategies in general cardiac surgery seem to be beneficial in severe disease, none have conclusively been proven most effective. Off-pump surgery in coronary artery bypass grafting should be preferred with severe atherosclerosis, if the required expertise is present. Although transcatheter aortic valve replacement is used as an alternative to surgery in patients with a porcelain aorta, the risk profile concerning intimal atherosclerosis remains poorly defined.

CONCLUSIONS

A tailored approach that uses the discussed alternative strategies in carefully selected patients is best suited to reduce the risk of perioperative stroke without compromising other outcomes. More research is needed, especially on the perioperative stroke risk in patients with moderate aortic atherosclerosis.

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.

Femoral arterial cannulation remains a safe and reliable option for aortic dissection repair

Background

The optimal cannulation site for repair of type A aortic dissection remains controversial. The concern for Malperfusion syndrome has initiated a national trend away from femoral cannulation to axillary artery and direct ascending aortic cannulation. The purpose of this study was to report a single center experience with femoral artery cannulation for the repair of a type A dissection.

Methods

A retrospective study was performed on 52 patients who underwent surgical repair for a type A dissection between January 1^st, 2012 and June 30^th, 2019 at a single institution. Of the 52 patients analyzed, 35 (67.3%) underwent femoral artery, 11 (21.2%) direct ascending aortic, and 6 (11%) axillary artery cannulation for arterial access. Deep hypothermic circulatory arrest was used in all the patients. Rates of postoperative complication and mortality were reported.

Results

The mortality and bleeding rates for all the patients undergoing repair of the type A dissection repairs were 27% (14/52) and 19% (10/52), respectively. Cardiopulmonary bypass was established in 100% of the patients that had femoral arterial cannulation. There were no complications specifically related to femoral arterial cannulation nor the axillary or direct aortic approach. Specifically, there was no episodes of malperfusion syndrome, bleeding, or injury with femoral artery cannulation. Bleeding rates were higher in cases that proceeded with a femoral (13%) versus alternate (6%) approach however; neither of the bleeding was related to the cannulation site. None of the mortalities identified were directly attributable to the cannulation approach in each case.

Conclusions

Despite the recent shift away from femoral cannulation, the results of the study show that femoral artery cannulation is safe and produces excellent results for establishing cardiopulmonary bypass. The concerns for malperfusion syndrome related to femoral cannulation were not seen.

Femoral artery cannulation as a safe alternative for aortic dissection arch repair in the era of axillary artery cannulation

BACKGROUND

To evaluate the safety and efficacy of femoral artery cannulation as an alternative to axillary artery cannulation, we retrospectively compared outcomes between patients with axillary or femoral artery cannulation during open aortic arch repair for type A aortic dissection (TAAD).

METHODS

Between January 2014 and January 2019, 646 patients underwent open aortic arch repair with circulatory arrest for TAAD using antegrade selective cerebral perfusion (SACP) and were divided into two groups according to the site of arterial cannulation: an axillary artery group (axillary group, n=558) or a femoral artery group (femoral group, n=88). The axillary artery was considered as the primary cannulation site, and the femoral artery was used as an alternative when axillary artery cannulation was deemed unsuitable or had failed. Propensity score matching was performed to correct baseline differences.

RESULTS

After propensity score matching, the patients' characteristics were comparable between groups (n=85 in each). The incidence of in-hospital mortality (10.6% vs. 14.1%; P=0.642) and stroke (3.5% vs. 5.9%; P=0.720) were comparable between the axillary and femoral groups. The incidence of newly required dialysis was lower in the femoral group, but the difference was not statistically significant (34.1% vs. 20.0%; P=0.050). Other outcomes and major adverse events were comparable.

CONCLUSIONS

Femoral artery cannulation produced similar perioperative outcomes to axillary cannulation after open arch repair for TAAD. The femoral artery can be used as a safe and effective alternative to the axillary artery for arterial cannulation in TAAD patients undergoing open arch repair.

Innominate artery dissection due to selective cerebral antegrade perfusion

We present the first case of successfully treated innominate artery dissection as a complication of selective cerebral antegrade perfusion during reoperative aortic valve and hemiarch replacements. Innominate artery dissection was suspected based on unilateral decreases in the right radial arterial pressure and right cerebral oximetry value. Intraoperative ultrasonography demonstrated minimal flow in the right internal carotid. A right aortoaxillary bypass graft was performed leading to immediate improvements in the right radial arterial pressure waveform and right cerebral oximetry. The patient was discharged neurologically intact on postoperative day six.

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.

Anaesthetic management in endovascular total aortic arch repair via needle-based in situ fenestration: a case series of 14 patients

Objective

Endovascular total aortic arch repair (ETAAR) via needle-based in situ fenestration (ISF) is a major challenge for anaesthesiologists because of haemodynamic instability and the risk of cerebral hypoxia. We herein summarise our experience with anaesthetic management of patients who underwent this procedure.

Methods

Fourteen patients who underwent ETAAR via ISF for arch pathologies involving the major supra-arch branches were included. Regional cerebral oxygen saturation was measured to monitor cerebral perfusion. Partial extracorporeal circulation (EC) support from the right common femoral vein to the right axillary artery was introduced to provide cerebral perfusion.

Results

During ISF, vessel rupture occurred in three patients and ventricular fibrillation occurred in one patient. The regional cerebral oxygen saturation significantly decreased during the potential risk period for cerebral ischaemia. Establishment of EC effectively prevented cerebral ischaemia.

Conclusions

During ETAAR, the risks of haemodynamic instability caused by the procedure and vessel rupture during ISF need to be overcome. Partial EC ensured good cerebral protection in our study, and regional cerebral oxygen saturation monitoring may help to reduce the rate of desaturation.

Factors associated with acute stroke after type A aortic dissection repair: An analysis of the Society of Thoracic Surgeons National Adult Cardiac Surgery Database

OBJECTIVES

Data from the Society of Thoracic Surgeons Adult Cardiac Surgery Database was used to examine the incidence and factors associated with acute stroke following type A repair.

METHODS

Acute type A aortic dissection repairs performed from 2014 to 2017 were identified from the Society of Thoracic Surgeons Adult Cardiac Surgery Database. The effect of cannulation strategy (eg, axillary, femoral, direct, or innominate), lowest temperature, cerebral protection techniques (antegrade cerebral profusion, retrograde cerebral perfusion, both, or none), repair technique, and institutional volume on postoperative stroke was investigated.

RESULTS

Acute type A repair was performed on 8937 patients at 772 centers, of which 7353 met inclusion criteria. Operative mortality was 17% and incidence of postoperative stroke was 13%. Axillary cannulation was associated with lower risk of stroke versus femoral (odds ratio, 0.60; P < .001). Retrograde cerebral perfusion was associated with reduced risk for stroke compared with no cerebral perfusion (odds ratio, 0.75; P = .008) or antegrade cerebral perfusion (odds ratio, 0.75; P = .007). Total arch replacement was associated with greater risk for stroke versus hemiarch technique (odds ratio, 1.30; P = .013). Longer circulatory arrest time, cerebral perfusion time, and cardiopulmonary bypass time were all related to higher risk of postoperative stroke.

CONCLUSIONS

Stroke is a common complication after type A repair. Axillary cannulation was associated with lower incidence of stroke, whereas femoral cannulation significantly increased the risk of stroke regardless of the cerebral perfusion strategy or the degree of hypothermia. Retrograde cerebral profusion was found to have reduced risk for postoperative stroke. Degree of hypothermia and center volume were not related to stroke incidence.

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.

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.

Factors predictive for early and late mortality after surgical repair for Stanford A acute aortic dissection

OBJECTIVES

The aim of this study was to evaluate independent risk factors predictive for mortality of patients with Stanford A acute aortic dissection.

METHODS

From January 2006 to March 2015, a total of 240 consecutive patients diagnosed with acute Stanford A acute aortic dissection underwent surgical aortic repair in our center. After analysis of pre- and perioperative variables, univariate logistic and multivariate logistic regression analyses were performed for mortality of patients. Subsequently, Kaplan-Meier estimation analysis of short- and long-term survival of these variables was carried out.

RESULTS

Primary entry tear in descending aorta (odds ratio = 4.71, p = 0.021), preoperative international normalized ratio higher than 1.2 (odds ratio = 7.36, p = 0.001), additional coronary artery bypass grafting (odds ratio = 3.39, p = 0.003), cannulation in ascending aorta (odds ratio = 3.22, p = 0.005), preoperative neurological coma (odds ratio = 3.30, p = 0.003), and reduced perfusion (odds ratio = 2.91, p = 0.006) as well as prolonged reperfusion time (odds ratio = 3.36, p = 0.002) showed to be independent predictors for early mortality as well as for late mortality (hazard ratio of all variables p < 0.05). Kaplan-Meier survival estimation analysis with up to 9-year-follow-up in terms of these risk factors showed significantly poorer short- and long-term survival (log-rank and Breslow test all p < 0.05).

CONCLUSION

Our study revealed that early and late mortality of patients with Stanford A acute aortic dissection surgery was significantly influenced by preoperative and perioperative variables as independent predictors especially of variables displaying coronary, cerebral, and visceral malperfusion. Also, short- and long-term survival of patients was significantly poorer in terms of these risk factors.

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.

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.

Open repair techniques in the aortic arch are still superior

Conventional arch replacement can be carried out in a great majority of patients. Hybrid procedures are often as invasive and technically difficult as conventional ones. Moreover, their immediate results are, in many reported experiences, not better and their long-term results less favourable than the ones observed with conventional methods. So, yes, the open conventional arch replacement is still "the gold standard".

Brain protection in aortic arch aneurysm: antegrade or retrograde?

During open aortic arch repair, there is an interruption of cerebral perfusion and to prevent neurological sequelae, the hypothermic circulatory arrest has been established to provide sufficient brain protection coupled with adjuncts including retrograde and antegrade cerebral perfusion. To date, brain protection during open aortic arch repair is a contested topic as to which provides superior brain protection with little evidence existing to suggest supremacy of one modality over the other. This article reviews current literature reflecting on key and emerging studies in brain protection and their associated outcomes in patients undergoing open aortic arch surgery.

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.

A Protocol for Diagnosis and Management of Aortic Atherosclerosis in Cardiac Surgery Patients

In patients undergoing cardiac surgery, use of perioperative screening for aortic atherosclerosis with modified TEE (A-View method) was associated with lower postoperative mortality, but not stroke, as compared to patients operated on without such screening. At the time of clinical implementation and validation, we did not yet standardize the indications for modified TEE and the changes in patient management in the presence of aortic atherosclerosis. Therefore, we designed a protocol, which combined the diagnosis of atherosclerosis of thoracic aorta and the subsequent considerations with respect to the intraoperative management and provides a systematic approach to reduce the risk of cerebral complications.

Recannulation of the axillary artery in aortic and complex cardiac surgery

OBJECTIVES

Axillary artery cannulation has been used as an alternative site for cardiopulmonary bypass during surgery for aortic dissections and aneurysmal disease of the ascending aorta and arch. This study reports our experience with reusing the axillary artery for cardiopulmonary bypass during complex aortic and cardiac surgical procedures.

METHODS

This was a retrospective review of a single surgeon's experience of recannulating the axillary artery for redo operations in complex aortic surgery. Seven patients over a 7-year period have undergone recannulation of their axillary arteries. The old Dacron graft stump was either excised and a new graft was anastamosed to the axillary artery or a new end-to-side anastamosis was performed either proximal or distal to the original graft stump.

RESULTS

There were no deaths, strokes, or postoperative complications. In one patient, axillary cannulation was aborted intraoperatively due to high-line pressures, suggesting a local dissection. The other patients all had adequate perfusion via the recannulated axillary artery and there were no complications associated with its reuse.

CONCLUSIONS

Recannulation of the axillary artery is easily achievable and should be considered in redo aortic and complex cardiac surgery.

Hybrid repair of aortic arch aneurysms: a comprehensive review

Open total arch replacement (TAR) has become safer with refinements in cerebral protection techniques. The frequent extension of aortic arch aneurysms into the descending thoracic aorta customarily requires a two-staged conventional elephant trunk procedure, carrying relatively high mortality and morbidity risks and high rates of rupture in the interval between the two open surgeries. The technical demands and invasive nature of TAR has therefore precluded many high-risk patients from being surgical candidates for aneurysm repair. As a result, hybrid techniques and approaches to the aortic arch have become common since the adoption of thoracic endovascular aortic repair (TEVAR) and advancement in the commercial grafts that are available. The results of hybrid aortic arch repairs have been encouraging, though with higher rates of re-interventions than TAR and variable reported rates of stroke and spinal cord ischemia. The aim of this publication is to review the current literature on hybrid repair of aortic arch aneurysms.

Dynamic alterations in cerebral, celiac and renal flows resulting from ascending aorta, subclavian artery and femoral artery cannulations of extracorporeal devices

INTRODUCTION

The aim of this study was to assess the relationships among cardiac output, extracorporeal blood flow, cannulation site, right (RCa) and left carotid (LCa), celiac (Ca) and renal artery (Ra) flows during extracorporeal circulation.

METHODS

A mock circulatory circuit was assembled, based on a compliant anatomical aortic model. The ascending aorta, right subclavian and femoral artery cannulations were created and flow was provided by a centrifugal pump (Cp); cardiac output was provided by a roller pump (Rp). Five volume flow rates were tested. The Rp was set at 4 L/min with no Cp flow (R⁴-C⁰) and the basic volume flow rates of the vessels were measured. The flow of the Cp was increased while the Rp flow was decreased for other measurements; R³-C¹, R²-C², R¹-C³ and R⁰-C⁴. Measurements were repeated for all cannulation sites.

RESULTS

The RCa flow rate at R⁴-C⁰ was higher compared to the R³-C¹, R²-C², R¹-C³ and R⁰-C⁴ RCa flows with subclavian cannulation. The RCa flow decreased as the Cp flow increased (p<0.05). The RCa flow with ascending aortic and femoral cannulation was higher compared to subclavian cannulation. Higher flows were obtained with subclavian cannulation in the LCa compared to the others (p<0.05). R⁴-C⁰ Ca and Ra flows were higher compared to other Ca and Ra flows with femoral cannulation. Ca and Ra flows decreased as Cp flow increased. Flows of the Ca and Ra with ascending and subclavian cannulations were not lower compared to the R⁴-C⁰ flow (p<0.05).

CONCLUSION

This study shows that prolonged extracorporeal circulation may develop flow decrease and ischemia in cerebral and abdominal organs with both subclavian and femoral cannulations.

Preprocedural Computed Tomography Evaluation for Minimally Invasive Mitral Valve Surgery: What the Surgeon Needs to Know

The proven success of endoscopic and videoscopic surgery combined with recent advancements in telemanipulation has made the performance of minimally invasive cardiac surgery a clinical reality during the past decade. A complete understanding of the basic concepts of minimally invasive surgery and the recent advancements in peripheral cardiopulmonary bypass techniques help the cardiac imager to provide a clinically meaningful interpretation for the surgical team. In this article we present an overview of minimally invasive mitral valve surgery and the fundamentals of preprocedural computed tomography angiography imaging and highlight the usefulness of cardiac computed tomography as a supplementary tool to echocardiography.

Optimal temperature management in aortic arch operations

Hypothermic circulatory arrest is a critical component of aortic arch procedures, without which these operations could not be safely performed. Despite the use of hypothermia as a protective adjunct for organ preservation, aortic arch surgery remains complex and is associated with numerous complications despite years of surgical advancement. Deep hypothermic circulatory arrest affords the surgeon a safe period of time to perform the arch reconstruction, but this interruption of perfusion comes at a high clinical cost: stroke, paraplegia, and organ dysfunction are all potential-associated complications. Retrograde cerebral perfusion was subsequently developed as a technique to improve upon the rates of neurologic dysfunction, but was done with only modest success. Selective antegrade cerebral perfusion, on the other hand, has consistently been shown to be an effective form of cerebral protection over deep hypothermia alone, even during extended periods of circulatory arrest. A primary disadvantage of using deep hypothermic circulatory arrest is the prolonged bypass times required for cooling and rewarming which adds significantly to the morbidity associated with these procedures, especially coagulopathic bleeding and organ dysfunction. In an effort to mitigate this problem, the degree of hypothermia at the time of the initial circulatory arrest has more recently been reduced in multiple centers across the globe. This technique of moderate hypothermic circulatory arrest in combination with adjunctive brain perfusion techniques has been shown to be safe when performing aortic arch operations. In this review, we will discuss the evolution of these protection strategies as well as their relative strengths and weaknesses.

A right thoracotomy approach for mitral and tricuspid valve surgery in patients with previous standard sternotomy: comparison with a re-sternotomy approach

BACKGROUND

To compare the outcomes of mitral and/or tricuspid valve surgery in patients with previous sternotomy between those who underwent a right thoracotomy and those who underwent re-sternotomy.

METHODS

Between October 2009 and May 2015, eighteen patients underwent a right thoracotomy (R group) and 28 underwent re-sternotomy (re-S group). The right thoracotomy was prioritized for previous coronary artery bypass grafting. Follow-up was 100 % complete with a mean follow-up of 1.9 ± 1.5 years for the R group and 2.5 ± 1.4 years for the re-S group (p = 0.2137).

RESULTS

Hypothermic ventricular fibrillation was applied in 33.3 % in the R group and in 7.1 % in the re-S group (p = 0.0424). Hospital mortality, the median intensive care unit stay, and the median postoperative hospital stay were 0 % versus 7.1 % (p = 0.5130), 3 days versus 2 days (p = 0.2370), and 28 days versus 29.5 days (p = 0.8043) for the R group versus the re-S group, respectively. Although the rate of major complications was comparable (R group 33.3 % versus re-S group 25.0 %, p = 0.5401), those contents were not equal. Deep sternum infection developed only in the re-S group (3.6 %) and reoperation for bleeding was required only in the R group (11.1 %). No significant difference was observed in the 2-year cardiac-related mortality-free rate (R group 93.3 ± 6.4 % versus re-S group 90.8 ± 6.4 %, p = 0.7516).

CONCLUSIONS

Given study limitations, the right thoracotomy approach after previous sternotomy provided favorable outcomes as well as re-sternotomy. When selecting a right thoracotomy for re-do mitral and/or tricuspid surgery, the surgical strategy needs to be thoroughly planned.