Bilateral Cerebral Perfusion Research Articles

Application of Bilateral Cerebral Perfusion + Balloon Occlusion of Descending Aorta + Antegrade Perfusion of Lower Body in Debakey Type I Aortic Dissection.

To evaluate the efficacy of a new perfusion method in DeBakey Type I aortic dissection surgery, with the goal of enhancing thorough organ protection and optimising patient outcomes. Descriptive study. Place and Duration of the Study: Department of Thoracic and Cardiovascular Surgery, The First Affiliated Hospital of the University of South China, from January 2020 to December 2021. Thirty-two patients undergoing total aortic arch replacement with descending aortic stenting were included in the study. The new perfusion method involved a combination of bilateral selective cerebral perfusion, descending aortic balloon occlusion, and antegrade lower body perfusion. Lower limb ischaemic complications and mortality rate were the main outcome measures. Surgical procedures and patient data were collected and analysed. No cases of paraplegia, intestinal necrosis, or lower-limb ischaemia were observed. The new perfusion method effectively protected lower-body organs, with a short duration of lower-body ischaemia during surgery. The overall mortality rate was 3.13%, and postoperative complications were minimal, resulting in satisfactory survival rates. The combination of perfusion techniques, including bilateral selective cerebral perfusion, descending aortic balloon occlusion, and anterograde lower body perfusion, proved effective in improving the outcomes for DeBakey Type I aortic dissection surgery. Further research is needed to confirm the long-term benefits of this approach. DeBakey type I aortic dissection, Descending aortic balloon blockade, Lower body anterograde perfusion, Bilateral selective cerebral perfusion.

Hypoperfusion of Amygdala in Chronic Migraine: An Exploratory Quantitative Perfusion Imaging Using 3D Pseudo-Continuous Arterial Spin Labeling.

Although the amygdala has structural and functional abnormalities in Chronic Migraine (CM), less is known about the altered perfusion of the amygdala in CM. The current study aimed to assess amygdala perfusion in CM using a contrast agent-free and quantitative approach. 15 Normal Controls (NC) and 13 patients with CM during the migraine interval were assessed for brain structure and subjected to 3D Pseudo- Continuous Arterial Spin Labeling (3D-PCASL) MR imaging. The Cerebral Blood Flow (CBF) value of the amygdala was automatically extracted based on the individual amygdala mask for all participants. The independent sample t-test, Receiver Operating Characteristic (ROC) curve, and correlation analysis were used to evaluate the perfusion changes in CM. Bilateral amygdala cerebral perfusion was lower in CM (left amygdala, 42.21±4.49 ml/100mg/min; right amygdala, 42.38±4.41 ml/100mg/min) than in NC (left amygdala, 48.31±6.92 ml/100mg/min; right amygdala, 47.88±6.53 ml/100mg/min) (left, p = 0.01; right, p = 0.02). There was no significant correlation between the perfusion of bilateral amygdalas and the clinical variables. Also, there was no significant difference in the volume of bilateral amygdalas between the two groups. The Area Under the Curve (AUC) of the CBF values of the left and right amygdala was 0.78 (95%CI: 0.58-0.91) and 0.75 (95%CI: 0.55-0.89), respectively. The cut-off value was 44.24 ml/100mg/min (left amygdala, with sensitivity 76.90% and specificity 78.70%) and 46.75 ml/100mg/min (right amygdala, with sensitivity 92.3% and specificity 58.80%), respectively. CM presented bilateral hypoperfusion in the amygdala, offering potential diagnostic value in distinguishing CM from NC. The 3D-PCASL could be regarded as a simple and efficient neuroimaging tool to assess the perfusion status in CM patients.

Investigation of the Association between Bilateral Selective Anterograde Cerebral Perfusion and Postoperative Ischemic Stroke in Obese Patients with Emergency Surgery for Acute Type A Aortic Dissection.

Background and objectives: The relationship between cerebral perfusion and new postoperative ischemic stroke in obese patients is not well defined. The aim of this study was to investigate the association between selective bilateral anterograde cerebral perfusion and new postoperative ischemic stroke in obese patients with emergency surgery for acute type A aortic dissection. Materials and methods: A total of 292 patients with emergency surgery for acute type A aortic dissection were included in this study. Patients with hemorrhagic stroke or ischemic stroke with severe neurological dysfunction at admission that were not candidates for surgery; patients who died in the first 48 h after intensive care admission and patients with incomplete medical records were excluded. Results: The mean age was 59.42 ± 10.68 years and the mean Euroscore was 9.12 ± 1.63. Obesity was present in 76.4%, the incidence of new postoperative ischemic stroke was 27.5%, and the postoperative mortality rate was 26.7%. The mean cardiopulmonary bypass time was 206.81 ± 75.48 min, the aortic cross-clamp time was 118.2 ± 46.42 min, and 90% of cases required cerebral perfusion. The mean cerebral perfusion time was 30.8 ± 24.41 min. Obese patients had a higher frequency of in-hospital death (p = 0.009), smoking (p = 0.036), hypertension (p = 0.023), left common carotid artery dissection (p < 0.001), right common carotid artery dissection (p = 0.029), femoral artery cannulation (p = 0.026), aortic root replacement (p = 0.009), aortic valve replacement (p = 0.005) and early reintervention for bleeding (p = 0.004). Using logistic regression, selective bilateral anterograde cerebral perfusion over 40 min in obese patients was independently associated with new postoperative ischemic stroke (OR = 2.35; 95%CI = 1.36-4.86; p = 0.021). Conclusions: A patient-tailored strategy for cerebral perfusion should be considered in obese patients, considering the high atheromatous burden of the supra-aortic vessels in these patients and the potential risk of atheromatous embolization associated with this technique.

Meta-analysis: Bilateral and Unilateral Cerebral Perfusion in Type A Dissection.

This meta-analysis compared the outcomes of bilateral cerebral perfusion (BCP) and unilateral cerebral perfusion (UCP) in aortic surgery for acute type A aortic dissection. A systematic literature search identified 12 studies involving 4,547 patients. Pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated to analyze perioperative characteristics, short-term mortality rates, and postoperative neurological complications. No significant differences were found between the BCP and UCP groups in terms of cardiopulmonary bypass time, aortic cross clamp time, lowest body temperature, and lower body circulatory arrest time. Short-term mortality rates (OR [95% CI] = 0.87 [0.64-1.19], p = 0.40) and permanent neurological deficits (OR [95% CI] = 1.01 [0.69-1.47], p = 0.96) were comparable between the groups. However, subgroup analysis of studies exclusively involving total arch replacement showed a lower short-term mortality rate (OR [95% CI] = 0.42 [0.28-0.63], p < 0.01) and permanent neurological deficits (OR [95% CI] = 0.53 [0.30-0.92], p = 0.03) in the BCP group. The BCP group also had a lower rate of temporary neurological deficits (OR [95% CI] = 0.70 [0.53-0.93], p = 0.01), particularly in studies exclusively involving total arch replacement (OR [95% CI] = 0.58 [0.40-0.85], p < 0.01). This meta-analysis suggests that BCP and UCP yield comparable outcomes. However, BCP may be associated with lower short-term mortality rates and reduced incidence of neurological complications, particularly in cases requiring total arch replacement. BCP should be considered as a preferred cerebral perfusion in specific patient populations.

A comparison of bilateral and unilateral cerebral perfusion for total arch replacement surgery for non-marfan, type A aortic dissection.

Acknowledging lacking of consensus exist in total aortic arch (TAA) surgery for acute type A aortic dissection (AAD), this study aimed to investigate the neurologic injury rate between bilateral and unilateral cerebrum perfusion on the specific population. A total of 595 AAD patients other than Marfan syndrome receiving TAA surgery since March 2013 to March 2022 were included. Among them, 276 received unilateral cerebral perfusion (via right axillary artery, RCP) and 319 for bilateral cerebral perfusion (BCP). The primary outcome was neurologic injury rate. Secondary outcomes were 30-day mortality, serum inflammation response (high sensitivity C reaction protein, hs-CRP; Interleukin-6, IL-6; cold-inducible RNA binding protein, CIRBP) and neuroprotection (RNA-binding motif 3, RBM3) indexes. The BCP group reported a significantly lower permanent neurologic deficits [odds ratio: 0.481, Confidence interval (CI): 0.296-0.782, p = 0.003] and 30-day mortality (odds ratio: 0.353, CI: 0.194-0.640, p < 0.001) than those received RCP treatment. There were also lower inflammation cytokines (hr-CRP: 114 ± 17 vs. 101 ± 16mg/L; IL-6: 130 [103,170] vs. 81 [69,99] pg/ml; CIRBP: 1076 [889, 1296] vs. 854 [774, 991] pg/ml, all p < 0.001), but a higher neuroprotective cytokine (RBM3: 4381 ± 1362 vs 2445 ± 1008pg/mL, p < 0.001) at 24h after procedure in BCP group. Meanwhile, BCP resulted in a significantly lower Acute Physiology, Age and Chronic Health Evaluation (APACHE) Ⅱscore (18 ± 6 vs 17 ± 6, p < 0.001) and short stay in intensive care unit (4 [3,5] vs. 3 [2,3] days, p < 0.001) and hospital (16 ± 4 vs 14 ± 3days, p < 0.001). This present study indicated that BCP compared with RCP was associated with lower permanent neurologic deficits and 30-day mortality in AAD patients other than Marfan syndrome receiving TAA surgery.

P48 RETROSPECTIVE POSTOPERATIVE NEAR INFRARED SPECTROSCOPY MONITORING ANALYSIS TO DETECT POTENTIAL CRITERIA TO IMPROVE POSTOPERATIVE PREDICTION OF UNFAVOURABLE OUTCOME FOLLOWING AORTIC SURGERY

Abstract Objective Near Infrared Spectroscopy (NIRS) monitoring has become a frequent practice during aortic surgery. The real impact of NIRS in predicting postoperative outcomes, however is still debated, as many cases of “false negative” with severe cerebral damage despite apparently normal NIRS monitoring during surgical procedure. We applied extended retrospective postoperative NIRS monitoring analysis in order to investigate potential criteria to enhance postoperative unfavorable outcome prediction. Materials and Methods Data of NIRS monitoring of 41 patients undergoing aortic surgery (19 acute dissection) were retrospectively analyzed. Partial circulatory arrest with selective bilateral (21 pts) or unilateral (20 pts) cerebral perfusion (CP) was used in all patients. Double channel (R and L) NIRS value was continuously recorded (every 30 sec) from anaesthetic induction to patient’s transfer to ICU. Postoperatively all data were downloaded in excel format and retrospectively analyzed. Baseline, maximum, and minimum value with percentage drop and R/L channel gap were all analyzed considering 5 different phases of surgery: before extracorporeal circulation (EC); in EC before circulatory arrest and selective cerebral perfusion (CA–SCP); in EC following CA–SCP, following EC. Overall time &amp;lt;25% (in each channel) or with a &amp;gt; 20% gap were also evaluated. Results Overall 661±125 values were recorded for each patient. Baseline value on the Left (61±7) was significantly lower then Right (66±12). Maximum drop did not differed in two channels (Fig 1a) but varied according surgical phases (Fig 1). R/L asymmetry also varied according surgical phases with a peak value during rewarming and not during CA–SCP despite unilateral SCP and complexity of procedure (Figure 2 and 3). Conclusion Extended postoperative analysis of NIRS recorded value shows different trend and behavior according surgical phase and cerebral perfusion strategy. Accurate extended NIRS analysis is therefore mandatory in order to improve knowledge of physiological cerebral perfusion during SCP and early identification of patients at high risk of postoperative cerebral complications.

Unilateral versus bilateral anterograde cerebral perfusion in acute type A aortic dissection repair: A systematic review and meta-analysis.

The aim of the study is to compare the safety and efficacy of unilateral anterograde cerebral perfusion (UACP) and bilateral anterograde cerebral perfusion (BACP) for acute type A aortic dissection (ATAAD). A systematic review of the MEDLINE (PubMed), Scopus, and Cochrane Library databases (last search: August 7th, 2021) was performed according to the PRISMA statement. Studies directly comparing UACP versus BACP for ATAAD were included. Random-effects meta-analyses were performed. Eight retrospective cohort studies were identified, incorporating 2416 patients (UACP: 843, BACP: 1573). No statistically significant difference was observed regarding in-hospital mortality (odds ratio [OR]:1.05 [95% Confidence Interval (95% CI):0.70-1.57]), permanent neurological deficit (PND) (OR: 0.94 [95% CI: 0.52-1.70]), transient neurological deficit (TND) (OR: 1.37 [95% CI: 0.98-1.92]), renal failure (OR: 0.96 [95% CI: 0.70-1.32]), and re-exploration for bleeding (OR: 0.77 [95% CI: 0.48-1.22]). Meta-regression analysis revealed that PND and TND were not influenced by differences in rates of total arch repair, Bentall procedure, and concomitant CABG in UACP and BACP groups. Cardiopulmonary bypass time (Standard Mean Difference [SMD]: -0.11 [95% CI: -0.22, 0.44]), Cross clamp time (SMD: -0.04 [95% CI: -0.38, 0.29]), and hypothermic circulatory arrest time (SMD: -0.12 [95% CI: -0.55, 0.30]) were comparable between UACP and BACP. Intensive care unit stay was shorter in BACP arm (SMD:0.16 [95% CI: 0.01, 0.31]); however, length of hospital stay was shorter in UACP arm (SMD: -0.25 [95% CI: -0.45, -0.06]). UACP and BACP had similar results in terms of in-hospital mortality, PND, TND, renal failure, and re-exploration for bleeding rate in patients with ATAAD. ICU stay was shorter in the BACP arm while LOS was shorter in the UACP arm.

Unilateral versus bilateral cerebral perfusion during aortic surgery for acute type A aortic dissection: a multicentre study.

The aim of this retrospective multicentre study was to investigate and compare clinical outcomes of unilateral and bilateral antegrade cerebral perfusion (ACP) strategies on cerebral protection during surgery for type A aortic dissection. Data from 646 patients who underwent surgical repair of thoracic type A aortic dissection using unilateral and bilateral ACP with moderate hypothermic circulatory arrest in 3 cardiac surgical institutions between 2008 and 2018 were analysed. Propensity matching was performed to assess which technique ensured better outcomes. Unilateral and bilateral ACP techniques were performed in 250 (39%) and in 396 (61%) patients, respectively. Propensity score analysis identified 189 matched pairs. In the matched cohort, the lowest core temperature was 27.5°C and 28°C in the bilateral and unilateral groups, respectively (P < 0.001). The unilateral technique required significantly shorter aortic cross-clamp and cardiopulmonary bypass times than bilateral technique [82 min vs 100 min (P < 0.001); 170 min vs 195 min (P < 0.001)]. The 30-day mortality was comparable (P = 0.325). The bilateral group reported a significantly higher incidence of permanent neurologic deficits (P < 0.001), left brain hemisphere stroke (P = 0.007) and all-combined complications (P < 0.001). Ten-year survival was comparable (P = 0.45). Unilateral and bilateral ACP are both valid brain protection strategies in the landscape of aortic arch surgery. While admitting all the study limitations, unilateral technique could offer some clinical advantages. 76049.

A novel modification of frozen elephant trunk technique: unique protocol from one institution.

We aim to present a novel surgical technique of Frozen Elephant Trunk (FET) to treat complex thoracic aortic diseases in one stage and report its short-term outcomes. Between December 2019 and 30 April 2021, twenty-five patients underwent FET operation at Viet Duc University Hospital. The mean age of the patients was 55.9 (±9.9, range 33-72) years. Eighteen (72%) of the patients were men. Thoracic aortic aneurysm was presented in three (12%) patients. Among seventeen (68%) of the patients undergoing the aortic dissection, eleven (44%) were treated acute type A aortic dissection. Type A intramural hematoma was presented in three (12%) patients. Four (16%) of the patients had undergone previous aortic operations, four (16%) of them had Marphan syndrome and two (11.1%) of them had stage 3 chronic kidney disease. All patients underwent FET procedure by unique protocol. Brain protection was achieved by antegrade bilateral selective cerebral perfusion and moderate hypothermia (28°C) in all cases; besides cerebral tissue oximetry monitoring was used to control brain oxygenation. There were no perioperative deaths, and all patients are still alive during mild-term follow-up period. Sixteen (88.9%) patients received isolated FET, while a Bentall procedure during FET was performed in two (8%) patients and right coronary artery bypass was in one (4%) case. The duration of cardiopulmonary bypass, cross-clamping, circulatory arrest, and total operation were 176.7 (±48.1, range 102-330), 106 (±39.8, range 63-205), 32.7 (±9.6, range 20-58), and 365.6 (±53.6, range 270-480) min, respectively. There was no bleeding following surgery. Prolonged ventilation required tracheotomy was documented in two (8%) patients, hemodialysis caused acute renal failure was in five (20%) patients, cerebral shock was in one (4%) patient, and type 1A endoleak in 2 (8%) patients. Our modification of FET technique was feasible, effective, and safe, with good postoperative outcomes.

Unilateral or bilateral cerebral perfusion in hemiarch replacement: A prospective randomized study.

We designed a prospective randomized clinical study to compare unilateral and bilateral antegrade cerebral perfusion (ACP) under moderate hypethermia in open distal aortic hemiarch replacement in ascending aortic aneurysm. Forty-two patients were prospectively randomized into two groups; unilateral ACP to Group 1 and bilateral ACP to Group 2. Inclusion criteria were pathological aortic aneurysm in the ascending aorta and/or aortic arch, elective operation, normal preoperative carotid Doppler ultrasonography, and nonexistence of preoperative neurological event. Patients were evaluated with preoperative and postoperative biochemical blood analysis, magnetic resonance imaging (MRI), and neurological disorders. The primary endpoints were permanent neurological disorder and death. There were 21 patients in each group. Mean age was 56.57 ± 10.06 years in Group 1 and 50.95 ± 15.64 years in Group 2 (p = .170). No significant difference was found according to demographic data. ACP times were significantly higher in bilateral ACP (Group 1: 12.62 ± 5.04 min, Group 2: 18.23 ± 9.04 min, p = .018) whereas cross-clamp time and cardiopulmonary bypass times were not (p = .693 and p = .584 sequentially). Transient neurological disorder was found in seven patients in Group 1 and in 4 patients in Group 2 (p = .484). Postoperative MRI revealed new milimetric ischemic zones in three patients in Group 1 but none in Group 2. No permanent neurological disorder or mortality was seen. The present randomized clinical prospective study could not prove the superiority of one of the technique in cerebral protection probably because, our overall ACP time was too short.

Different hypothermic and cerebral perfusion strategies in extended arch replacement for acute type a aortic dissection: a retrospective comparative study

BackgroundThe optimal hypothermic level in total arch replacement with stented elephant trunk implantation for acute type A aortic dissection (aTAAD) has not been established, and the superiority of unilateral or bilateral cerebral perfusion remains a controversial issue. Therefore, we evaluated the application of moderate hypothermic circulatory arrest (MHCA) with a core temperature of 29 °C and bilateral selective antegrade cerebral perfusion in aTAAD treated by total arch replacement with stented elephant trunk implantation.MethodsFrom July 2019 to January 2020, 25 aTAAD patients underwent total arch replacement with stented elephant trunk implantation via MHCA (29 °C) and bilateral selective antegrade cerebral perfusion (modified group). Thirty-six patients treated by the same procedure with MHCA (25 °C) and unilateral selective antegrade cerebral perfusion during this period were selected as controls.ResultsThere were no differences between the two groups of patients in terms of age, sex, incidence of hypertension, malperfusion, and pericardial effusion, although the incidence of cardiac tamponade was higher in the modified group (control 2.8%, modified 20%; P = 0.038). The lowest mean circulatory arrest temperature was 24.6 ± 0.9 °C in the control group, and 29 ± 0.8 °C in the modified group (P < 0.001). In-hospital mortality was 4.9% (3/61) for the entire cohort (control 8.3%, modified 0; P = 0.262). The incidence of permanent neurologic deficit was 4.9% (control 8.3%, modified 0; P = 0.262). There were no significant differences in the occurrence of temporary neurological deficit, renal failure, and paraplegia between groups. The rate of major adverse events in the modified group was lower (30.6% vs. 4%, P = 0.019). A shorter duration of ventilation and ICU stay was identified in the modified group, as well as a reduced volume of drainage within the first 48 h and red blood cell transfusion.ConclusionsThe early results of MHCA (29 °C) and bilateral selective antegrade cerebral perfusion applied in total arch replacement with stented elephant trunk implantation for aTAAD were acceptable, providing similar inferior cerebral and visceral protection compared with that of the conventional strategy. A higher core temperature may account for the shorter duration of ventilation and ICU stay, as well as a reduced volume of drainage and red blood cell transfusion.

Sun's total arch replacement and stent elephant trunk with modified branch-first technique for patients with Stanford type A aortic dissection.

BackgroundStanford type A aortic dissection (STAAD) is a critical cardiovascular disease, and surgical procedure is the first-choice treatment. The classical surgical procedure still leads to a high mortality rate and neurological complications. In this study, we introduce a new modified Sun’s procedure and investigate the association between the branch-first technique and the postoperative outcomes of patients with STAAD.MethodsA total of 108 consecutive patients with STAAD who underwent arch replacement and stent elephant trunk procedure at Beijing Anzhen Hospital between July, 2017 and November, 2018 were included in the analysis. The patients were divided into two groups: the branch-first group and the classic group. The branch-first group and the classic group comprised 24 patients (22.2%) and 84 patients (77.8%), respectively.ResultsPatients in the branch-first group had a significantly shorter cardiopulmonary bypass (CPB) duration (172.4±29.9 vs. 194.9±47.4 min; P=0.035), Intensive care unit (ICU) stay [17.0 (14.6–38.2) vs. 42.1 (19.7–87.2) hours; P<0.001], and mechanical ventilation time [15.5 (11.9–40.0) vs. 19.0 (17.0–45.6) hours; P=0.018] than patients in the classic group. The branch-first was associated with a reduction in postoperative neurological complications in all models.ConclusionsThe benefits of the branch-first technique, including lower CPB duration, better bilateral cerebral perfusion, and higher nasopharyngeal temperature during hypothermic arrest, contributed to a shortened recovery time for patients after surgery.

Bilateral or unilateral antegrade cerebral perfusion during surgery for acute type A dissection

ObjectiveThe study objective was to investigate outcomes associated with the application of bilateral or unilateral antegrade cerebral perfusion during surgery for acute type A dissection. MethodsPatients who underwent surgery for type A dissection with the application of antegrade cerebral perfusion between 2009 and 2017 at the Division of Cardiac Surgery, Medical University of Vienna were analyzed retrospectively (bilateral antegrade cerebral perfusion: n = 91, 49.5%; unilateral antegrade cerebral perfusion: n = 93, 50.5%). The primary outcome variable was overall survival. Subgroup analyses were performed in patients requiring antegrade cerebral perfusion durations of 50 minutes or more and less than 50 minutes. Secondary outcome variables were 30-day mortality, adverse outcome, permanent and temporary neurologic deficits, renal replacement therapy, prolonged ventilation, intensive care unit stay, and hospital stay. ResultsMultivariable Cox proportional hazards analysis demonstrated no significant association of bilateral antegrade cerebral perfusion with overall survival (hazard ratio, 0.63; 95% confidence interval, 0.34-1.14, P = .126). Propensity score modeling using the method of inverse probability of treatment weighting confirmed this result (hazard ratio, 0.73; 95% confidence interval, 0.33-1.60, P = .428). Bilateral antegrade cerebral perfusion was associated with significantly improved overall survival in patients requiring antegrade cerebral perfusion durations of 50 minutes or more (P = .017). The bilateral antegrade cerebral perfusion and unilateral antegrade cerebral perfusion groups showed comparable rates of secondary outcome variables. ConclusionsIn the present study, bilateral antegrade cerebral perfusion and unilateral antegrade cerebral perfusion are associated with comparable outcomes after surgery for type A dissection. Subgroup analyses suggest that bilateral antegrade cerebral perfusion is associated with superior overall survival in patients requiring antegrade cerebral perfusion durations of 50 minutes or more. An adequately powered prospective randomized controlled trial is required to validate these results.

Evaluation of the SONAS® Ultrasound Device for the Assessment of Bilateral Cerebral Perfusion in Subjects With Acute Stroke

Evaluation of the SONAS® Ultrasound Device for the Assessment of Bilateral Cerebral Perfusion in Subjects With Acute Stroke

Moderate Hypothermic Circulatory Arrest (≥ 28°C) with Selective Antegrade Cerebral Perfusion for Total Arch Replacement with Frozen Elephant Trunk Technique.

The optimal hypothermic level during circulatory arrest in aortic arch surgery remains controversial, particularly in frozen elephant trunk (FET) procedures. We describe herein our experience for total arch replacement with FET technique under moderate systemic hypothermic circulatory arrest (≥ 28°C) during selective antegrade cerebral perfusion. Between January 2009 and January 2016, 38 consecutive patients underwent elective total arch replacement for various aortic arch pathologies with FET technique using the E-vita Open hybrid prosthesis (Jotec GmbH, Hechingen, Germany). Selective unilateral or bilateral cerebral perfusion under moderate systemic hypothermic circulatory arrest (28.7°C ± 0.5°C) was used in all patients. Minimally invasive total arch replacement with FET via partial upper sternotomy was performed in 15 patients (39%) and in the remaining 23 patients (61%) via full sternotomy. Mean late follow-up was 3 ± 2 years and was 98% complete. Clinical data were prospectively entered into our institutional database. Cardiopulmonary bypass time accounted for 198 ± 58 minutes and the myocardial ischemic time 109 ± 29 minutes. Selective antegrade cerebral perfusion time was 55 ± 6 minutes. Lower body circulatory arrest time was 39 ± 11 minutes. Unilateral cerebral perfusion was performed in 31 patients (82%), and bilateral in 7 patients (18%). Intensive care unit stay was 4 ± 3 days. Thirty-day mortality was 5% (n = 2). Late survival at 3 years was 87 ± 3%. Two patients (5%) required reexploration for bleeding. Patients were discharged after a hospital length of stay of 7 ± 2 days. Postoperative permanent neurologic complication occurred in two patients (5%). Three patients (8%) experienced a transient neurologic disorder. New transient renal replacement therapy was necessary in three patients (8%). No spinal cord injury was noted. Our data suggest that moderate systemic hypothermic circulatory arrest (≥ 28°C) in combination with antegrade cerebral perfusion can safely be applied for total aortic arch replacement with FET and offers sufficient neurologic and visceral organ protection.

Intraoperative care for aortic surgery using circulatory arrest.

The total circulatory arrest (CA) is necessary to achieve optimal surgical conditions in certain aortic pathologies, especially in those affecting the ascending aorta and aortic arch. During this procedure it is necessary to protect all the organs of ischemia, especially those of the central nervous system and for this purpose several strategies have been developed. The first and most important protective method is systemic hypothermia. The degree of hypothermia and the route of application have been evolving and currently tend to use moderate hypothermia (MH) (20.1-28 °C) associated with unilateral or bilateral selective cerebral perfusion methods. In this way the neurological results are better, the interval of security is greater and the times of extracorporeal circulation are smaller. Even so, it is necessary to take into account that there is the possibility of ischemia in the lower part of the body, especially of the abdominal viscera and the spinal cord, therefore the time of circulatory stop should be limited and not to exceed 80 minutes. Evidence of possible neurological drug protection is very weak and only mannitol, magnesium, and statins can produce some benefit. Inhalational anesthetics and some intravenous seem to have advantages, but more studies would be needed to test their long-term benefit. Other important parameters to be monitored during these procedures are blood glucose, anemia and coagulation disorders and acid-base balance. The recommended monitoring is common in complex cardiovascular procedures and it is of special importance the neurological monitoring that can be performed with several techniques, although currently the most used are Bispectral Index (BIS) and Near-Infrared Spectroscopy (NIRS). It is also essential to monitor the temperature routinely at the nasopharyngeal and bladder level and it is important to control coagulation with rotational thromboelastometry (ROTEM).

Bilateral versus unilateral antegrade cerebral perfusion in total arch replacement for type A aortic dissection

BackgroundAntegrade cerebral perfusion (ACP) is the most widely used cerebral protection strategy for complex aortic repair and includes unilateral (u-ACP) and bilateral (b-ACP) techniques. The superiority of b-ACP over u-ACP has been the subject of much debate. Focusing on type A aortic dissection requiring total arch replacement, we investigated the clinical effects of b-ACP versus u-ACP. MethodsBetween September 2006 and August 2014, 203 patients presenting with type A aortic dissection (median age, 51.0 ± 13 years; range, 17-72 years; 128 males) underwent total aortic arch replacement with hypothermic circulatory arrest. ACP was used in all patients, including u-ACP in 82 (40.3%) and b-ACP in 121 (59.7%). ResultsThere was no significant difference between the u-ACP and b-ACP groups in terms of cardiopulmonary bypass (CPB) time, cross-clamp time, or circulatory arrest time. Overall 30-day mortality was comparable in the 2 groups (11.6% for b-ACP vs 20.7% for u-ACP; P = .075). The prevalence of postoperative permanent neurologic dysfunction (PND) was comparable as well (8.4% vs 16.9%; P = .091). Mean ventilation time was lower in the b-ACP group (95.5 ± 45.25 hours vs 147.0 ± 82 hours; P < .001). Mean lengths of stay in the intensive care unit and the hospital overall were comparable in the 2 groups (intensive care unit: 16 ± 17.75 days vs 17 ± 11.5 days, P = .454; hospital: 26.5 ± 20.6 days vs 24.8 ± 10.3 days, P = .434). The P values from logistic regression models indicated that in the 2 groups combined, CPB time and circulatory arrest time were independent risk factors for both mortality and PND. ConclusionsIn this, the first published study focusing on the efficacy of u-ACP and b-ACP in total arch replacement for type A aortic dissection, the b-ACP group did not demonstrate significantly lower 30-day mortality or PND rate compared with the u-ACP group. Future large-sample studies are warranted to thoroughly examine this critical issue.

Macrovascular and microvascular cerebral blood flow in adults at risk for Alzheimer's disease

IntroductionCapillary hypoperfusion is reported in asymptomatic adults at-risk for Alzheimer's disease (AD), but the extent that can be explained by reduced flow in intracranial arteries is unknown. MethodsOne hundred fifty-five asymptomatic adults enriched for AD risk (mean age 61 years) completed arterial spin labeling (pcASL) and 4D-flow MRI sequences. Voxel-wise regression models investigated the relationship between mean flow in bilateral cerebral arteries and capillary perfusion, and tested potential moderators of this relationship. ResultsMean arterial blood flow through middle cerebral arteries (MCAs) and internal carotid arteries was positively associated with perfusion in large cortical clusters (P < .05, false discovery rate corrected). Trends were observed for the interactions MCA flow × age and MCA flow × cardiovascular risk on cerebral perfusion (P < .001, uncorrected). DiscussionThese findings provide evidence that capillary perfusion measured via pseudocontinuous arterial spin labeling is strongly dependent on inflow from larger cerebral arteries. Further studies are warranted to investigate possible alterations between macrovascular and microvascular flow in advanced age and elevated cardiovascular risk in asymptomatic adults at risk for AD.

Fifteen years of surgery for acute type A aortic dissection in moderate-to-mild systemic hypothermia†.

Surgery for acute type A aortic dissection remains a surgical challenge because of prolonged operative times, bleeding complications, and a considerable risk of neurological morbidity and mortality. The following study investigates the clinical results after surgical treatment for acute type A aortic dissection using selective antegrade cerebral perfusion and moderate-to-mild systemic hypothermia (≥28 °C). Between January 2000 and January 2015, 453 consecutive patients underwent surgical treatment for acute type A aortic dissection at two aortic referral centres in Germany. Patient mean age was 67 ± 13 years, 298 patients (66%) were male. Selective unilateral or bilateral cerebral perfusion under moderate-to-mild systemic hypothermia was used in all patients. Ascending aortic replacement, hemiarch replacement and total arch replacement was performed in 9 patients (2%), 342 patients (75%) and 102 patients (23%), respectively. Clinical data were prospectively entered into the institutional databases. Mean late follow-up was 6 ± 3 years and was 98% complete. Cardiopulmonary bypass time totalled 181 ± 68 min and the myocardial ischaemic time 107 ± 43 min. Mean duration of selective antegrade cerebral was 46 ± 23 min. Mean lowest core temperature amounted to 28.8 ± 0.6 °C. Unilateral cerebral perfusion was performed in 298 patients (66%) and bilateral in 155 patients (34%). Mean intensive care unit stay was 5 ± 7 days. We observed new postoperative permanent neurological deficits in 27 patients (6%) and transient neurological deficits in 31 patients (7%). Thirty-day mortality was 7% (n = 32). Overall survival rate at 5 years was 77 ± 6%. Our data suggest that selective antegrade cerebral perfusion in combination with moderate-to-mild systemic hypothermia (≥28 °C) can be safely and reproducibly applied to surgery for acute type A aortic dissection and offers sufficient neurological and visceral organ protection.

Cerebral perfusion issues in acute type A aortic dissection without preoperative malperfusion: how do surgical factors affect outcomes?

Both preoperative (disease-related) and operative (management-related) variables make the assessment of the outcomes of acute type A aortic dissection (ATAAD) surgery a difficult task. Our aim was to evaluate the impact of operative factors, including arterial cannulation site, route of cerebral perfusion and surgeon's specific experience with ATAAD ('aortic surgeon'), on the early results of surgical management, with particular attention to neurological injury. Penn classification was used to identify clinically homogeneous risk groups of ATAAD patients undergoing surgery. Between January 2007 and June 2014, 111 of 183 ATAAD patients treated with open surgery in a single centre were in Penn Class Aa (no ischaemic complications at presentation). They were divided in two groups depending on the arterial cannulation site: femoral artery (FemA; 56 patients) or right axillary artery (RAxA; 55 patients). Study outcomes included: 30-day mortality, major adverse cardiac and cerebrovascular events at 30 days, neurological complications and in particular, patterns of stroke as defined by Bamford classification. No significant differences in preoperative variables were observed between cannulation-site groups, except for myocardial ischaemic time (60.9 ± 30.4 min in the RAxA group vs 81.7 ± 52.3 in the FemA group, P = 0.014) and cerebral perfusion time (42.1 ± 25.5 min in the RAxA group vs 52.9 ± 32.6 in the FemA group, P = 0.048). Outcomes in terms of mortality and neurological injury did not differ except for a higher incidence of lacunar cerebral infarction (LACI) in the RAxA group (14.5 vs 3.6%, P = 0.043), mainly but not exclusively explained by a higher incidence of LACI in unilateral (17.2%) than in bilateral cerebral perfusion (6.9%) within the RAxA group. The 'non-aortic surgeon' was associated instead with 30-day mortality and composite outcome in multivariable analysis (respectively, OR 6.40, P = 0.002 and OR 4.68, P = 0.001). The RAxA cannulation and FemA cannulation are associated with comparable 30-day mortality following surgery for aortic dissection. However, the possible higher risk of LACI-type strokes in the RAxA group, especially when associated with unilateral brain perfusion, should be considered when RAxA cannulation is performed in ATAAD. The hypothesis that more experienced surgeons may produce better earlier outcomes warrants further investigation.