Search

We aimed to determine the effects of selective antegrade cerebral perfusion compared with other perfusion strategies on indices of cerebral blood flow, oxygenation, cellular stress, and mitochondrial function. One-week-old piglets (n = 41) were assigned to 5 treatment groups. Thirty-eight were placed on cardiopulmonary bypass. Of these, 30 were cooled to 18°C and underwent deep hypothermic circulatory arrest (n = 10), underwent selective antegrade cerebral perfusion at 10 mL/kg/min (n = 10), or remained on continuous cardiopulmonary bypass (deep hypothermic cardiopulmonary bypass, n = 10) for 40 minutes. Other subjects remained on normothermic cardiopulmonary bypass (n = 8) or underwent sham surgery (n = 3). Novel, noninvasive optical measurements recorded cerebral blood flow, cerebral tissue oxyhemoglobin concentration, oxygen extraction fraction, total hemoglobin concentration, and cerebral metabolic rate of oxygen. Invasive measurements of cerebral microdialysis and cerebral blood flow were recorded. Cerebral mitochondrial respiration and reactive oxygen species generation were assessed after the piglets were killed. During hypothermia, deep hypothermic circulatory arrest piglets experienced increases in oxygen extraction fraction (P <. 001), indicating inadequate matching of oxygen supply and demand. Deep hypothermic cardiopulmonary bypass had higher cerebral blood flow (P =. 046), oxyhemoglobin concentration (P =. 019), and total hemoglobin concentration (P =. 070) than selective antegrade cerebral perfusion, indicating greater oxygen delivery. Deep hypothermic circulatory arrest demonstrated worse mitochondrial function (P <. 05), increased reactive oxygen species generation (P <. 01), and increased markers of cellular stress (P <. 01). Reactive oxygen species generation was increased in deep hypothermic cardiopulmonary bypass compared with selective antegrade cerebral perfusion (P <. 05), but without significant microdialysis evidence of cerebral cellular stress. Selective antegrade cerebral perfusion meets cerebral metabolic demand and mitigates cerebral mitochondrial reactive oxygen species generation. Excess oxygen delivery during deep hypothermia may have deleterious effects on cerebral mitochondria that may contribute to adverse neurologic outcomes. We describe noninvasive measurements that may help guide perfusion strategies. [Display omitted] [ABSTRACT FROM AUTHOR]

We aimed to monitor regional oxygen saturation levels using near-infrared spectroscopy in patients undergoing total aortic arch replacement and to determine the range of collateral flow via antegrade cerebral perfusion to the spinal cord during lower body circulatory arrest. Eighteen consecutive patients undergoing total aortic arch replacement in our hospital were prospectively enrolled. Optodes of near-infrared spectroscopy were attached to the skin at the right and left forehead, and above the paravertebral muscles at the level of the third (T3) and tenth (T10) thoracic vertebra. Within- and between-group differences were compared using mixed-effect model repeated-measures analysis. Regional oxygen saturation levels, which had been rapidly declining immediately after circulatory arrest at a tympanic temperature of <25°C and a core temperature of <30°C, showed a rapid increase at the forehead with the initiation of antegrade cerebral perfusion (total flow rate 0.81 ± 0.08 L/min, perfusion pressure 37 ± 6 mm Hg, temperature 25°C). Saturation levels remained only partially elevated at the upper thoracic level (T3) and continued to decline without showing signs of recovery at the lower thoracic level (T10). Antegrade cerebral perfusion partially perfused the upper thoracic cord via collateral circulation from vertebral arteries through an anterior spinal artery, but it did not reach the lower thoracic cord sufficiently to change the oxygenation level. Cooling is a more important means of protection for the lower spinal cord during lower body circulatory arrest than is antegrade cerebral perfusion. [ABSTRACT FROM AUTHOR]

This study sought to report outcomes of hemiarch replacement with hypothermic circulatory arrest and retrograde cerebral perfusion, and secondarily, to report outcomes of this operative approach by type of underlying aortic disease. This was an observational study of aortic surgeries from 2010 to 2018. All patients who underwent hemiarch replacement with retrograde cerebral perfusion were included, whereas patients undergoing partial or total arch replacement or concomitant elephant trunk procedures were excluded. Patients were dichotomized into 2 groups by underlying aortic disease; that is, acute aortic dissection (AAD) or aneurysmal degeneration of the aorta. These groups were analyzed for differences in short-term postoperative outcomes, including stroke and operative mortality (Society of Thoracic Surgeons definition). Multivariable Cox analysis was performed to identify variables associated with long-term survival after hemiarch replacement. A total of 500 patients undergoing hemiarch replacement with hypothermic circulatory arrest plus retrograde cerebral perfusion were identified, of whom 53.0% had aneurysmal disease and 47.0% had AAD. For the entire cohort, operative mortality was 6.4%, whereas stroke occurred in 4.6% of patients. Comparing AAD with aneurysm, operative mortality and stroke rates were similar across each group. Five-year survival was 84.4% ± 0.02% for the entire hemiarch cohort, whereas 5-year survival was 88.0% ± 0.02% for the aneurysm subgroup and was 80.5% ± 0.03% for the AAD subgroup. On multivariable analysis, AAD was not associated with an increased hazard of death, compared with aneurysm (P =.790). Morbidity and mortality after hemiarch replacement with hypothermic circulatory arrest plus retrograde cerebral perfusion are acceptably low, and this operative approach may be as advantageous for AAD as it is for aneurysm. In an observational study of 500 hemiarch replacements under deep hypothermic circulatory arrest with retrograde cerebral perfusion from 2010 and 2018, operative mortality was 6.4% for the entire cohort, whereas strokes occurred in 4.6% of patients. Both aneurysms and acute dissections were included in this study and were compared for differences in outcomes after hemiarch replacement. Kaplan-Meier survival estimates were generated. Five-year survival was 84.4% ± 0.02% for the entire hemiarch cohort. Finally, multivariable Cox analysis was performed to identify variables associated with long-term survival after hemiarch replacement. On multivariable analysis, acute aortic dissection was not associated with an increased hazard of death, compared with aneurysm (P =.790). [Display omitted] [ABSTRACT FROM AUTHOR]

Background Antegrade 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. Methods Between 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%). Results There 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. Conclusions In 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. [ABSTRACT FROM AUTHOR]

Objective Excellent outcomes have been established for elective aortic root replacement (ARR). It is less clear whether extending the repair into the proximal aortic arch with hypothermic circulatory arrest increases risk. We examined the early outcomes of elective, primary ARR, with and without hemiarch replacement, in patients without previous cardiac surgery. Methods Over a 4-year period, 140 non-redo patients (median age, 54 years) underwent elective, primary ARR for root aneurysms; 119 patients (85%) had hemiarch replacement, and 21 (15%) had only ascending aortic replacement. Valve-sparing ARR was performed in 41 cases (29.3%) and valve-replacing ARR in 99 (70.7%). Moderate hypothermic circulatory arrest and antegrade cerebral perfusion were used in 118 (99%) hemiarch repairs. Results There were no operative deaths or permanent strokes. Complications included temporary renal dialysis (n = 1; 4.8%), transient neurologic deficit (n = 2; 9.5%), and tracheostomy (n = 2; 9.5%) after ascending aortic repair and bleeding requiring reoperation (n = 4; 3.4%), pericardial effusion requiring drainage (n = 9; 7.6%), and tracheostomy (n = 2; 1.7%) after hemiarch replacement. No stroke was observed in the hemiarch group ( P = .022; univariate analysis). The extent of the repair into the proximal arch did not appear to be associated with any adverse effect. Conclusions In non-redo patients, elective primary ARR has excellent early outcomes, regardless of whether repair extends into the proximal arch. Additional elective hemiarch replacement with moderate hypothermic circulatory arrest and antegrade cerebral perfusion has a low risk of neurologic complications and should be performed if necessary. Long-term data are needed to compare the rates of reintervention in the aortic arch in patients with or without proximal arch replacement. [ABSTRACT FROM AUTHOR]

Objective To evaluate adverse outcomes after elective aortic arch surgery performed at higher or lower temperatures (24.0°C-28.0°C vs 20.1°C-23.9°C) within the wide range of moderate hypothermia. Methods Over a 9-year period, a total of 665 patients underwent elective proximal (n = 479) or total (n = 186) arch replacement with moderate hypothermia and antegrade cerebral perfusion. Circulatory arrest was initiated at an actual temperature of 20.1°C to 23.9°C in the lower-temperature group (n = 334; 223 proximal, 111 total) and at 24.0°C to 28.0°C in the higher-temperature group (n = 331; 256 proximal, 75 total). Composite adverse outcome was defined as operative mortality or persistent neurologic event or persistent hemodialysis at discharge. Multivariate logistic regression analysis was used to model adverse outcome. In addition to the actual temperature, a new, balanced variable, “predicted temperature,” was analyzed to eliminate surgeon bias. We used this variable in a propensity score–matching analysis to validate the multivariate analysis results. Results A composite adverse outcome occurred in 7.2% of cases. Operative mortality was 5.1%. The rate of postoperative persistent neurologic deficits was 2.4%. No significant differences were found between the lower– and higher–predicted temperature groups within the moderate hypothermia range in the propensity score–matching analysis. The higher–actual temperature group had a lower rate of ventilator support at >48 hours ( P = .036) and less need for tracheostomy ( P = .023). Packed red blood cell transfusion and previous coronary artery bypass independently predicted composite adverse outcome ( P = .0053 and .0002, respectively), operative mortality ( P = .0051 and .0041), and postoperative stroke ( P = .045 and .048). Cardiopulmonary bypass time independently predicted composite outcome ( P = .0005), operative mortality ( P < .0001), ventilatory support for >48 hours ( P < .0001), and renal dysfunction ( P = .0005). Conclusions In elective proximal or total arch surgery, higher temperatures (≥24.0°C-28.0°C) within the wide range of moderate hypothermia (20.1°C-28°C) are safe and, compared with colder temperatures, not associated with significantly different rates of composite and adverse outcomes. [ABSTRACT FROM AUTHOR]

Objective We examined the early outcomes and the long-term survival associated with different degrees of hypothermia in patients who received antegrade cerebral perfusion (ACP) for >30 minutes. Methods During a 10-year period, 544 consecutive patients underwent proximal and total aortic arch surgery and received ACP for >30 minutes and 1 of 3 levels of hypothermia: deep (14.1°C-20°C; n = 116 [21.3%]), low-moderate (20.1°C-23.9°C; n = 262 [48.2%]), and high-moderate (24°C-28°C; n = 166 [30.5%]). A variable called “predicted temperature” was used in propensity-score analysis. Multivariate analysis was done to evaluate the effect of actual temperature on outcomes. Results The operative mortality rate was 12.5% (n = 68) overall and was 15.5%, 11.8%, and 11.5% in the deep, low-moderate, and high-moderate hypothermia patients, respectively ( P = .54). The persistent stroke rate was 6.6% overall and 12.2%, 4.6%, and 6.0% in these 3 groups, respectively ( P = .024 on univariate analysis). On multivariate analysis, actual temperature was not associated with mortality, but lower temperatures predicted persistent stroke and reoperation for bleeding. In the propensity-matched subgroups, the patients with predicted deep hypothermia had (nonsignificantly) greater rates of persistent stroke (12.2% vs 4.9%; relative risk, 1.08; 95% CI, 0.87-1.15) and reoperation for bleeding (14.6% vs 2.4%; relative risk, 1.14; 95% CI, 0.87-1.15) than the patients with predicted moderate hypothermia. On long-term follow-up (mean duration, 5.12 years), 4- and 8-year survival rates were 62.3% and 55.7% in the deep hypothermia group and 75.4% and 74.2% in the moderate hypothermia group ( P = .0015). Conclusions In proximal and arch operations involving ACP for >30 minutes, greater actual temperatures were associated with less stroke and reoperation for bleeding. There were no significant differences among the predicted hypothermia levels, although a trend toward a higher rate of adverse events was noticed in the deep hypothermia group. Long-term survival was better in the moderate hypothermia group. [ABSTRACT FROM AUTHOR]

To evaluate the ability of intraoperative neurophysiologic monitoring (IONM) during aortic arch reconstruction with hypothermic circulatory arrest (HCA) to predict early (<48 hours) adverse neurologic events (ANE; stroke or transient ischemic attack) and operative mortality. This was an observational study of aortic arch surgeries requiring HCA from 2010 to 2018. Patients were monitored with electroencephalogram (EEG) and somatosensory evoked potentials (SSEP). Baseline characteristics and postoperative outcomes were compared according to presence or absence of IONM changes, which were defined as any acute variation in SSEP or EEG, compared with baseline. Multivariable logistic regression analysis was used to assess the association of IONM changes with operative mortality and early ANE. A total of 563 patients underwent aortic arch reconstruction with HCA and IONM. Of these, 119 (21.1%) patients had an IONM change, whereas 444 (78.9%) did not. Patients with IONM changes had increased operative mortality (22.7% vs 4.3%) and increased early ANE (10.9% vs 2.9%). In multivariable analysis, SSEP changes were correlated with early ANE (odds ratio [OR], 4.68; 95% confidence interval [CI], 1.51-14.56; P =.008), whereas EEG changes were not (P =.532). Permanent SSEP changes were correlated with early ANE (OR, 4.56; 95% CI, 1.51-13.77; P =.007), whereas temperature-related SSEP changes were not (P =.997). Finally, any IONM change (either SSEP or EEG) was correlated with operative mortality (OR, 5.82; 95% CI, 2.72-12.49; P <.001). Abnormal IONM events during aortic arch reconstruction with HCA portend worse neurologic outcomes and operative mortality and have a negative predictive value of 97.1%. SSEP might be more sensitive than EEG for predicting early ANE, especially when SSEP changes are permanent. In an observational study of 563 patients who received aortic arch surgery with hypothermic circulatory arrest and intraoperative neurophysiologic monitoring (IONM) from 2010 and 2018, all patients were monitored using electroencephalogram and somatosensory evoked potentials. Baseline characteristics and postoperative outcomes were compared according to presence or absence of IONM changes, which were defined as any acute variation in somatosensory evoked potentials or electroencephalogram, compared with baseline. One hundred nineteen (21.1%) patients had an IONM change, whereas 444 (78.9%) did not. Patients with IONM changes were more likely to have had operative mortality (22.7% vs 4.3%; P <.001) and were more likely to have had early adverse neurologic events, <48 hours after surgery (10.9% vs 2.9%; P <.001). Abnormal IONM events during aortic arch reconstruction might portend worse neurologic outcomes and increased operative mortality. [Display omitted] [ABSTRACT FROM AUTHOR]

To compare the short- and long-term outcomes of unilateral and bilateral antegrade cerebral perfusion (uni-ACP and bi-ACP) in acute type A aortic dissection (ATAAD) repair. From 2001 to 2017, 307 patients underwent surgical repair of an ATAAD using uni-ACP (n = 140) and bi-ACP (n = 167). Data were collected through the Department of Cardiac Surgery Data Warehouse, medical record review, and the National Death Index database. The demographics and preoperative comorbidities were similar between the uni-ACP and bi-ACP groups. Both groups had similar rates of procedures for aortic valve/root, ascending aorta, frozen elephant trunk, and other concomitant procedures. Perioperative outcomes were not significantly different between the 2 groups (30-day mortality: uni-ACP 3.4% vs bi-ACP 7.8%, P =.12) except reoperation for bleeding was significantly lower in uni-ACP (5% vs 12%, P =.03). Between the uni-ACP and bi-ACP groups, overall postoperative stroke rate (6% vs 9%, P =.4) and left brain stroke rate (0.7% vs 3.0%, P =.23) were not significantly different. The odds ratio of uni-ACP versus bi-ACP was 0.87 (P =.80) for postoperative stroke and 0.86 (P =.81) for operative mortality. The mid-term survival was better in the uni-ACP group, P =.027 (5-year: 84% vs 76%). The hazard ratio of all-time mortality for uni-ACP versus bi-ACP was 0.74 (95% confidence interval, 0.33-1.65), P =.46. In ATAAD, both uni-ACP and bi-ACP are equally effective to protect the brain with low postoperative stroke rates and mortality in hemiarch to zone 3 arch replacement. Uni-ACP is recommended for its simplicity and less manipulation of arch branch vessels. [ABSTRACT FROM AUTHOR]

The study objective was to investigate outcomes associated with the application of bilateral or unilateral antegrade cerebral perfusion during surgery for acute type A dissection. Patients 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. Multivariable 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. In 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. [ABSTRACT FROM AUTHOR]