Cerebral malperfusion in acute type A dissection: Direct innominate artery cannulation

Early mortality of emergency surgery for acute type A aortic dissection in octogenarians and nonagenarians: A multi-center retrospective study

OBJECTIVES

The clinical data on postoperative mortality and central nervous system (CNS) complications in older adults who underwent acute type A aortic dissection are limited. Thus, in this study we aimed to evaluate the association between age and early postoperative mortality and occurrence of CNS complications.

METHODS

This multicentric retrospective cohort study included 5 tertiary hospitals in Japan. All patients who underwent emergency surgery for acute type A aortic dissection between October 1998 and December 2019 were enrolled. The multilevel Cox proportional hazards model, which considered years as level 1, institutions as level 2, and surgeons as level 3, was used to evaluate the association between age and early postoperative hospital mortality and occurrence of CNS complications.

RESULTS

Of the 1037 patients, 227 (21.9%) were ≥80 years old and 810 (78.1%) were <80 years old. Overall, 134 patients (12.9%) died within 30 days postoperatively; among them, 42/227 (18.5%) and 92/810 (11.4%) were aged ≥80 and <80 years, respectively (hazard ratio [HR], 1.63; P = .0046). CNS complications within 30 days postoperatively occurred in 140/1037 (13.5%) patients; among them, 42/227 (18.5%) and 98/810 (12.1%) were aged ≥80 and <80 years, respectively (HR, 1.63; P = .011). In multivariate analysis, age ≥80 years was associated with mortality within 30 days postoperatively (adjusted HR, 2.37; 95% CI, 1.23-4.57; P = .01) but not with CNS complications (adjusted HR, 1.58; 95% CI, 0.93-2.69; P = .091).

CONCLUSIONS

The early postoperative mortality in older patients was approximately 50% higher than in the younger population. A thorough discussion regarding the surgical indications should be done.

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.

Stenting in Brain Hemodynamic Injury of Carotid Origin Caused by Type A Aortic Dissection: Local Experience and Systematic Literature Review

In this study, we report our local experience of type A aortic dissections in patients with cerebral malperfusion treated with carotid stenting before or after aortic surgery, and present a systematic literature review on these patients treated either with carotid stenting (CS) before or after aortic surgery (AS) or with aortic and carotid surgery alone (ACS). We report on patients treated in our center with carotid stenting for brain hemodynamic injury of carotid origin caused by type A dissection since 2018, and a systematic review was conducted in PubMed for articles published from 1990 to 2021. Out of 5307 articles, 19 articles could be included with a total of 80 patients analyzed: 9 from our center, 29 patients from case reports, and 51 patients from two retrospective cohorts. In total, 8 patients were treated by stenting first, 72 by surgery first, and 7 by stenting after surgery. The mean age; initial NIHSS score; time from symptom onset to treatment; post-treatment clinical improvement; post-treatment clinical worsening; mortality rate; follow-up duration; and follow-up mRS were, respectively, for each group (local cohort, CS before AS, ACS, CS after AS): 71.2 ± 5.3 yo, 65.5 ± 11.0 yo; 65.3 ± 13.1 yo, 68.7 ± 5.8 yo; 4 ± 8.4, 11.3 ± 8.5, 14.3 ± 8.0, 0; 11.8 ± 14.3 h, 21 ± 39.3 h, 13.6 ± 17.8 h, 13 ± 17.2 h; 56%, 71%, 86%, 57%; 11%, 28%, 0%, 14%; 25%, 12.3%, 14%, 33%; 5.25 ± 2.9 months, 54 months, 6.8 ± 3.8 months, 14 ± 14.4 months; 1 ± 1; 0.25 ± 0.5, 1.3 ± 0.8, 0.68 ± 0.6. Preoperative carotid stenting for hemodynamic cerebral malperfusion by true lumen compression appears to be feasible, and could be effective and safe, although there is still a lack of evidence due to the absence of comparative statistical analysis. The literature, albeit growing, is still limited, and prospective comparative studies are needed.

Impact of direct carotid artery perfusion in acute type A aortic dissection involving the common carotid artery

Objectives

Acute type A aortic dissection complicated with brain ischemia is associated with significantly higher mortality risks. Even if rescued with central aortic repair, some patients develop permanent postoperative neurological deficiency postoperatively. We recently introduced direct common carotid artery perfusion for acute type A aortic dissection involving the common carotid artery. This study introduced this technique to prevent postoperative neurological deficiency by comparing brain protection strategies.

Methods

Among 91 acute type A aortic dissection patients treated at our hospital during August 2015–October 2020, the common carotid artery was involved in 19 (21%), which had > 90% stenosis in either of the carotid arteries on preoperative contrast-enhanced computed tomography. Twelve patients underwent conventional selective cerebral perfusion during August 2015–December 2018 and seven patients underwent direct carotid artery perfusion during January 2019–October 2020. We assessed patient characteristics, surgical courses, clinical outcomes, and neurological outcomes.

Results

The mean age was 69 (range 39–84) years; 17 patients were male (89%). Eight patients (42%) had neurological symptoms. Concomitant procedures, postoperative neurological symptoms, and late mortality were significantly associated with conventional selective cerebral perfusion. Five selective cerebral perfusion patients experienced worsened neurological symptoms and two died of broad cerebral ischemia. No direct carotid artery perfusion patient died during hospitalization or experienced worsened neurological outcomes.

Conclusions

Direct carotid artery perfusion may be useful in aortic dissection with brain ischemia because it does not aggravate neurological symptoms and is not associated with intraoperative cerebral infarction. However, it may be ineffective when cerebral infarction has already developed.

Cerebral malperfusion in acute aortic dissection

Cerebral malperfusion in association with acute type A aortic dissection is uncommon but can have a considerable effect on the outcome of treatment. Successful treatment requires the individual and effective removal of each of the factors associated with malperfusion. In addition to the conventional surgical procedures, endovascular treatment has become an option for restoring perfusion. However, artificial perfusion and/or surgical procedures can lead to new malperfusion, which is not necessarily apparent to surgeons and which is difficult to predict. Thus, a number of modalities need to be applied to monitoring the current status of perfusion to enable timely treatment. Since each of the diagnostic modalities has its merits and demerits, one should use them effectively while being mindful of the pitfalls. In addition, a delay in the diagnosis in the pre-hospital stage is an important determinant of the surgical outcomes of aortic dissection. Portable echocardiography, which has been recently developed, may be useful for improving this situation. However, an early diagnosis largely depends on the physician's awareness and basic echocardiography skills. Surgeons should make general physicians aware of this message.

Clinical dilemma in the surgical treatment of organ malperfusion caused by acute type A aortic dissection

The malperfusion syndrome associated with acute aortic dissection draws attention because the clinical picture is very dramatic, and patients with malperfusion have poorer clinical outcomes. To improve surgical outcomes, the ischemic damages associated with organ malperfusion should be minimized by restoring perfusion as early as possible, which occasionally can hardly coexist with central repair. This paper reviews the current evidence, problems, and dilemma related to the diagnosis and treatment of the malperfusion syndrome caused by acute type A aortic dissection.

How I do it--sole innominate cannulation for acute type A aortic dissection

We describe sole direct innominate cannulation for arterial return for establishing both cardiopulmonary bypass and selective antegrade cerebral perfusion in the repair of acute type A dissection and compare it with femoral, axillary, direct aortic and apical cannulations. We believe innominate cannulation has all the advantages of right axillary cannulation and none of its disadvantages. It can be used in all patients in whom innominate artery is not dissected, obstructed, calcified or otherwise diseased.

Feasibility of cerebral near-infrared spectroscopy monitoring in the pre-hospital environment

BACKGROUND

Traumatic brain injury (TBI) is a significant cause of death and severe disability from trauma. Pre-hospital care of patients with TBI may be aided by non-invasive monitoring of cerebral tissue oxygenation. This pilot observational study was designed to assess if cerebral tissue oximetry using near-infrared spectroscopy (NIRS) is feasible in the pre-hospital and transport environment.

METHODS

After ethics committee review, we undertook a feasibility trial in healthy volunteers, transported by road ambulance or helicopter, to assess if monitoring signals could be obtained in the outside environment and during patient transport.

RESULTS

A total of 33 road ambulance transports and 32 helicopter transports were undertaken. For monitoring commenced outdoors, 33 of 66 probes applied (50%) provided adequate monitoring signal. For road transports, 33 out of 33 transports (100%) resulted in successful bilateral monitoring for more than 70% of the sampling period. For helicopter transports, four transports were cut short by battery failure during the mission and 24 of 28 transports (85.7%) resulted in successful bilateral monitoring for more than 70% of the sampling period. While patient and transport platform movement did not impact on monitoring signals, exposure to ambient light provided a challenge in obtaining monitoring signals that is nevertheless manageable with increased probe shielding.

CONCLUSIONS

NIRS monitoring is feasible in the pre-hospital environment, opening up the possibility for further research of the role of this modality in this setting.

Evidence, lack of evidence, controversy, and debate in the provision and performance of the surgery of acute type A aortic dissection

Acute type A aortic dissection is a lethal condition requiring emergency surgery. It has diverse presentations, and the diagnosis can be missed or delayed. Once diagnosed, decisions with regard to initial management, transfer, appropriateness of surgery, timing of operation, and intervention for malperfusion complications are necessary. The goals of surgery are to save life by prevention of pericardial tamponade or intra-pericardial aortic rupture, to resect the primary entry tear, to correct or prevent any malperfusion and aortic valve regurgitation, and if possible to prevent late dissection-related complications in the proximal and downstream aorta. No randomized trials of treatment or techniques have ever been performed, and novel therapies-particularly with regard to extent of surgery-are being devised and implemented, but their role needs to be defined. Overall, except in highly specialized centers, surgical outcomes might be static, and there is abundant room for improvement. By highlighting difficulties and controversies in diagnosis, patient selection, and surgical therapy, our over-arching goal should be to enfranchise more patients for treatment and improve surgical outcomes.

Near-infrared spectroscopy as an index of brain and tissue oxygenation

Continuous real-time monitoring of the adequacy of cerebral perfusion can provide important therapeutic information in a variety of clinical settings. The current clinical availability of several non-invasive near-infrared spectroscopy (NIRS)-based cerebral oximetry devices represents a potentially important development for the detection of cerebral ischaemia. In addition, a number of preliminary studies have reported on the application of cerebral oximetry sensors to other tissue beds including splanchnic, renal, and spinal cord. This review provides a synopsis of the mode of operation, current limitations and confounders, clinical applications, and potential future uses of such NIRS devices.

A Proposed Algorithm for the Intraoperative Use of Cerebral Near-Infrared Spectroscopy

Near-infrared spectroscopy (NIRS) is a technique that can be used as a noninvasive and continuous monitor of the balance between cerebral oxygen delivery and consumption. The authors develop and propose an algorithm for the use of NIRS based on optimizing factors that can affect cerebral oxygen supply/demand. These factors are the position of the vascular cannula, perfusion pressure, arterial oxygen content, partial pressure of carbon dioxide, haemoglobin, cardiac output, and the cerebral metabolic rate of oxygen. Dissemination of a useful treatment algorithm is the primary purpose of this article. Further multicenter studies are necessary to confirm the benefits and cost-effectiveness of this promising monitoring modality.