Circulatory Arrest In Aortic Surgery Research Articles

Early and long-term results of hypothermic circulatory arrest in aortic surgery: a 20-year single-centre experience.

The aim of this study was to document the postoperative outcomes of patients who underwent hypothermic circulatory arrest (HCA), the evolution of HCA management over time and to identify the risks factor for early mortality and postoperative stroke. Four hundred and twenty-four patients who underwent aortic surgery with HCA at our institution between January 1995 and June 2016 were consecutively included. The main indications were degenerative aneurysm (254; 59.9%) and acute type A aortic dissection (146; 34.4%). Interventions were performed under deep (18.4 ± 0.9°C; n = 350; 82.5%) or moderate (23.9 ± 1.9°C; n = 74; 17.5%) hypothermia. Antegrade cerebral perfusion (ACP) was employed in 86 (20.3%) cases. The use of moderate hypothermia significantly increased from 2011, to become the preferred strategy in 2016. The in-hospital mortality was 12.5% and the postoperative stroke rate was 7.1%. Kaplan--Meier 5-year survival was 65.7%. Nonelective timing [odds ratio (OR) 4.05; P < 0.001], stroke (OR 3.77' P = 0.032), renal failure (OR 2.49; P = 0.023), redo surgery (2.42; P = 0.049) and CPB time (OR 1.05; P = 0.03) were independent risk factors for in-hospital mortality in multivariate analysis. Femoral cannulation was the only independent risk factor for stroke (OR 3.97; P = 0.002). The level of hypothermia and the use of ACP were not associated with either in-hospital mortality or postoperative stroke. HCA might be widely considered to achieve a radical treatment of the aortic disease, provided that hypothermia is maintained below the 24°C safety threshold and ACP is used for HCA exceeding 30 min, to ensure optimal brain, spinal cord and visceral organs protection.

Noninvasive Neuromonitoring of Hypothermic Circulatory Arrest in Aortic Surgery.

Circulatory arrest carries a high risk of neurological damage, but modern monitoring methods lack reliability, and is susceptible to the generalized effects of both anesthesia and hypothermia. The objective of this prospective, explorative study was to research promising, reliable, and noninvasive methods of neuromonitoring, capable of predicting neurological outcome after hypothermic circulatory arrest. Thirty patients undergoing hypothermic circulatory arrest during surgery of the thoracic aorta were recruited in a single center and over the course of 4 years. Neuromonitoring was performed with a four-channel electroencephalogram montage and a near-infrared spectroscopy monitor. All data were tested off-line against primary neurological outcome, which was poor if the patient suffered a significant neurological complication (stroke, operative death). A poor primary neurological outcome seen in 10 (33%) patients. A majority (63%) of the cases were emergency surgery, and thus, no neurological baseline evaluation was possible. The frontal hemispheric asymmetry of electroencephalogram, as measured by the brain symmetry index, predicted primary neurological outcome with a sensitivity of 79 (interquartile range; 62%-88%) and specificity of 71 (interquartile range; 61%-84%) during the first 6 h after end of circulatory arrest. The hemispheric asymmetry of frontal electroencephalogram is inherently resistant to generalized dampening effects and is predictive of primary neurological outcome. The brain symmetry index provides an easy-to-use, noninvasive neuromonitoring method for surgery of the thoracic aorta and postoperative intensive care.

Long-Term Survival and Quality of Life After Hypothermic Circulatory Arrest in Aortic Surgery.

Hypothermic circulatory arrest carries a high risk of mortality and neurological complications. An important part of assessing surgical treatment is the evaluation of long-term survival and postoperative health-related quality of life. In this prospective study, 30 patients undergoing hypothermic circulatory arrest during surgery of the thoracic aorta, and 31 comparison patients undergoing elective coronary artery surgery without hypothermic circulatory arrest were evaluated for long-term survival and health-related quality of life, using the RAND 36-Item Health Survey questionnaire. The results were compared to national age- and sex-matched reference populations of the chronically ill and healthy adults. After 4.6-8.0 years, available study (88%) and comparison (59%) patients were interviewed. The life expectancy was similar with 4- and 8-year survival of 90%, and 87% for the study group, and 94%, and 94% for the comparison group, respectively (log rank test, p = 0.62). The RAND-36 scores for study and comparison groups were congruent in all dimensions, describing physical, mental, and social domains. The study patients' health-related quality of life results were similar to the national reference population with chronic illnesses. After hypothermic circulatory arrest, patients undergoing surgery of the thoracic aorta achieve a similar long-term life expectancy and health-related quality of life as do patients undergoing coronary surgery without hypothermic circulatory arrest, and a health-related quality of life similar to the national reference population with chronic illnesses. These results justify operative treatment in this high-risk patient population.

Invited Commentary

Invited Commentary

Similar Cerebral Protective Effectiveness of Antegrade and Retrograde Cerebral Perfusion During Deep Hypothermic Circulatory Arrest in Aortic Surgery: A Meta-Analysis of 7023 Patients

In aortic arch surgery, deep hypothermic circulatory arrest (DHCA) combined with cerebral perfusion is employed worldwide as a routine practice. Even though antegrade cerebral perfusion (ACP) is more widely used than retrograde cerebral perfusion (RCP), the difference in benefit and risk between ACP and RCP during DHCA is uncertain. The purpose of this meta-analysis is to compare neurologic outcomes and early mortality between ACP and RCP in patients who underwent aortic surgery during DHCA. PubMed, EMBASE, and the Cochrane Library were searched using the key words "antegrade," "retrograde," "cerebral perfusion," "cardiopulmonary bypass," "extracorporeal circulation," and "cardiac surgery" for studies reporting on clinical endpoints including early mortality, stroke, temporary neurologic dysfunction (TND), and permanent neurologic dysfunction (PND) in aortic surgery requiring DHCA with ACP or RCP. Heterogeneity was analyzed with the Cochrane Q statistic and I(2) statistic. Publication bias was tested with Begg's funnel plot and Egger's test. Thirty-four studies were included in this meta-analysis, with 4262 patients undergoing DHCA + ACP and 2761 undergoing DHCA + RCP. The overall pooled relative risk for TND was 0.722 (95% CI = [0.579, 0.900]), and the z-score for overall effect was 2.9 (P = 0.004). There was low heterogeneity (I(2) = 18.7%). The analysis showed that patients undergoing DHCA + ACP had better outcomes than those undergoing DHCA + RCP in terms of TND, while there were no significant differences between groups in terms of PND, stroke, and early mortality. This meta-analysis indicates that DHCA + ACP has an advantage over DHCA + RCP in terms of TND, while the two methods show similar results in terms of PND, early mortality, and stroke.

Direct innominate artery cannulation for selective antegrade cerebral perfusion during deep hypothermic circulatory arrest in aortic surgery

To demonstrate a novel, reproducible, and effective method of direct innominate artery cannulation using a 14 F pediatric venous cannula to establish antegrade cerebral protection (ACP) in patients undergoing aortic surgery that requires an open distal anastomosis or hemiarch replacement. We reviewed prospectively gathered data on all patients who had undergone replacement of the ascending aorta or hemiarch with an open distal anastomosis using deep hypothermic circulatory arrest and direct innominate artery cannulation with a 14 F pediatric venous cannula at our institution. After central cannulation and cooling to 25 °C to 28 °C, all patients had ACP initiated by way of a direct innominate cannula placed over a guidewire. Fifty patients underwent direct innominate artery cannulation with our technique from 2010 to 2012. The operative mortality was 2% (n = 1), and the rates of neurologic morbidity were acceptable and similar to those with other methods of ACP delivery: stroke (2%, n = 1), seizure (0%, n = 0), and delirium (18%, n = 9). The mean operative time was 31 ± 9, 19 ± 5, 100 ± 39, 141 ± 39, and 259 ± 63 minutes for cooling, circulatory arrest, crossclamp, cardiopulmonary bypass, and total operative time, respectively. No local or arterial complications were observed. Direct cannulation of the innominate artery using a 14 F pediatric venous cannula is a simple, reproducible, safe, and effective technique for establishing ACP in patients undergoing aortic surgery that requires an open distal anastomosis or hemiarch replacement. This technique avoids the additional time and potential local complications associated with other established methods for delivering ACP, such as axillary cannulation.

(772) - Influence of Junctional-Adhesion-Molecules on Transendothelial Migration Under Hypothermic Conditions: What About the Rewarming During Reperfusion?

Patients during circulatory arrest in aortic surgery or organ transplantation are subjected to therapeutic hypothermia. The body is cooled down or organs are perfused with cold preservation solutions and rewarmed again to body temperature. Hypothermia evokes anti-inflammatory responses and rewarming leads to pro-inflammatory responses. The role of hypothermia and the rewarming process on transendothelial migration (t-m) of leukocytes is not clarified yet. We investigated the influence of hypothermia/rewarming on t-m and the influence of Junctional-adhesion-molecules A and B (JAM-A; JAM-B) on this process.

Protective function of Junctional-adhesion-molecules in the rewarming process after mild hypothermia

Objective: During circulatory arrest in aortic surgery, patients are subjected to therapeutic hypothermia to reduce the risks of ischemic injury. Infiltration of pro-inflammatory cells into the surrounding tissue represents an additional hazard to patients undergoing aortic surgery. Junctional-adhesion-molecules (JAMs) are essential for the endothelial permeability and consequent transmigration. We investigated the influence of different hypothermic cell-activation temperatures followed by rewarming to 37°C on the expression of JAM-A, and JAM-B on endothelial cells after the rewarming process.

What about the rewarming during reperfusion? Influence of hypothermic conditions on endothelial activity

Objective: Patients with risks of ischemic injury, e.g. during circulatory arrest in aortic surgery, are subjected to therapeutic hypothermia. The body is cooled down to 18°C and rewarmed again to body temperature. Peripheral blood mononuclear cells (PBMC) under hypothermic conditions evoke anti-inflammatory, whereas subunits of PBMC show pro-inflammatory effects. First we investigates the influence of, mild and severe hypothermic conditions on transendothelial migration of activated or inactivated PBMC through activated or inactivated human endothelial cells (EC). Secondly we analyzed the influence of the reperfusion-rewarming-process upon endothelial cells.

Unilateral versus bilateral antegrade cerebral protection during circulatory arrest in aortic surgery: A meta-analysis of 5100 patients

Our objective was to determine whether the use of unilateral (u-ACP) or bilateral antegrade cerebral perfusion (b-ACP) results in different mortality and neurologic outcomes after complex aortic surgery. PubMed, Embase, and the Cochrane Library were searched for studies reporting on postoperative mortality and permanent (PND) and temporary neurologic dysfunction (TND) in complex aortic surgery requiring circulatory arrest with antegrade cerebral protection. Analysis of heterogeneity was performed with the Cochrane Q statistic. Twenty-eight studies were analyzed for a total of 1894 patients receiving u-ACP versus 3206 receiving b-ACP. Pooled analysis showed similar rates of 30-day mortality (8.6% vs 9.2% for u-ACP and b-ACP, respectively; P=.78), PND (6.1% vs 6.5%; P=.80), and TND (7.1% vs 8.8%; P=.46). Age, sex, and cardiopulmonary bypass time did not influence effect size estimates. Higher rates of postoperative mortality and PND were among nonelective operations and for highest temperatures and duration of the circulatory arrest. The Egger test excluded publication bias for the outcomes investigated. This meta-analysis shows that b-ACP and u-ACP have similar postoperative mortality and bothPND and TND rates after circulatory arrest for complex aortic surgery.

Evolving Knowledge About Age and Hypothermic Circulatory Arrest in Aortic Surgery

In ascending aortic surgery, progress in surgical and perfusion technology is continuous and quiet and does not produce frequent reports of short-term success. Changes in strategy show their effects years after their implementation, and may then be recommended to the broad community to adapt therapeutic strategy and thus to improve overall outcome. An example is the report by the Berne group1 in the current issue of Circulation on the effect of age on mortality and neurological injury in patients after surgical repair with hypothermic circulatory arrest in acute and chronic proximal thoracic pathology. Traditionally, age has been associated with a higher risk for both mortality and neurological injury, as has been shown by large databases such as the International Registry of Acute Aortic Dissection (IRAD).2 As a consequence, some centers refuse surgery in elderly patients because of dismal results, especially loss of quality of life, which has emerged as one of the most important surrogates for treatment success.3 Article see p 1407 However, the aforementioned reports stem from a time when deep hypothermic circulatory arrest was used as the only adjunctive technique for brain protection. Improvements in modern surgical therapy of aortic aneurysms include several important changes: subclavian artery perfusion, heparin-coated circuits for cardiopulmonary bypass, and most important, antegrade cerebral perfusion via the subclavian artery or selective perfusion catheters of supraaortic branches. Antegrade cerebral perfusion allows operating on the aortic arch in moderate hypothermia, thus reducing the side effects of deep hypothermia (eg, coagulopathy, inflammatory reactions). Additionally, concomitant treatment of the descending thoracic aorta with an open placement of a stent graft enables even more extensive repair of pathologies of the entire thoracic aorta. Commercially available trifurcated prostheses facilitate surgical aortic arch repair …