Total Arch Replacement with Hypothermic Circulatory Arrest, Antegrade Cerebral Perfusion and the Y-graft.

This study examines postoperative morbidity and mortality and long-term survival after total arch replacement (TAR) using deep to moderate hypothermic circulatory arrest (HCA), antegrade cerebral perfusion (ACP), and the Y-graft. Seventy-five patients underwent TAR with the Y graft. Deep to moderate HCA was initiated at 18-22°C. ACP was either initiated immediately (early ACP) or after the distal anastomosis was performed (late ACP). The arch vessels were then serially anastomosed to the individual limbs of the Y-graft. The median age was 66 years (range = 32-82). Etiology of aneurysmal dilatation included 20 (27%) patients with medial degenerations, 25 (33%) with chronic dissections, 14 (19%) with acute dissections, 9 (12%) with atherosclerosis and 2 (3%) with Marfan syndrome. In-hospital mortality was 5%. Neurologic complications occurred in 8 (11%) patients; 2 (3%) had strokes and 6 (8%) had transient neurologic deficits. Patients undergoing TAR with moderate hypothermia had a significantly higher incidence of new-onset renal insufficiency (3 [23%] vs [0%], P < 0.001) and TND (3 (23%) vs 3 (5%), P = 0.028) than the profound and deep hypothermia cohort. Excluding the 1 patient who died intraoperatively, 89% (95%CI: 79-94%) were alive at 1 year, 78% at 5 years (95%CI: 66-86%), and 73% at 10 years (95%CI: 59-82%). The combination of deep to moderate HCA, ACP, and the Y-graft is a safe and reproducible technique. Further inquiry is needed to assess if early ACP provides superior clinical outcomes.

Aortic arch surgery with hypothermic circulatory arrest and unilateral antegrade cerebral perfusion: Perioperative outcomes.

OBJECTIVE: The study objective was to determine the effects of surgical procedures, circulatory management strategies, and cerebral protection strategies on the short-term outcomes of aortic arch surgery based on the 7-year clinical experience of a single center. METHODS: We analyzed the data of 1708 patients who underwent aortic arch surgery with definite hypothermic circulatory arrest and unilateral antegrade cerebral perfusion at Beijing Anzhen Hospital between 2009 and 2015. Logistic regression and random Forest regression analyses were used to determine predictors and their effects on outcomes. RESULTS: Thirty-day mortality was 6.1%. Permanent neurologic dysfunction incidence was 4.8%. The proportion of patients requiring continuous renal replacement therapy was 7.9%. In multivariable analyses, age, DeBakey type I dissection, New York Heart Association score, coma, coronary artery bypass grafting, extra-anatomic bypass, and cardiopulmonary bypass time were independent risk factors for mortality. Age, DeBakey type I dissection, and cardiopulmonary bypass time were independent risk factors for permanent neurologic dysfunction. In the random Forest regression, the risk for permanent neurologic dysfunction and mortality increased when unilateral antegrade cerebral perfusion time was more than 38 minutes and decreased with an increase in nasopharyngeal temperature when temperature was lower than approximately 24°C. The risk for permanent neurologic dysfunction, continuous renal replacement therapy, and paraplegia increased when temperature was greater than approximately 24°C. CONCLUSIONS: The study showed that the largest reported cohort of patients undergoing aortic arch surgery with hypothermic circulatory arrest and unilateral antegrade cerebral perfusion had reasonable morbidity and mortality rates. As a cerebral protection strategy, unilateral antegrade cerebral perfusion may have a 38-minute safety threshold. Moderate hypothermia should be maintained below 24°C to reduce the risk for permanent neurologic dysfunction, paraplegia, and acute renal dysfunction requiring continuous renal replacement therapy.

Impact of Cerebral Perfusion on Outcomes of Aortic Surgery: The Society of Thoracic Surgeons Adult Cardiac Surgery Database Analysis.

BACKGROUND: Limited data inform cerebral protection during circulatory arrest. This study was designed to identify optimal approaches from a national clinical registry. METHODS: A total of 7830 adults (mean age, 63.1 years, SD 13.1 years) who underwent hemiarch (n = 6891; 88.0%) or total arch (n = 939; 12.0%) replacement with hypothermic circulatory arrest between 2014 and 2016 were identified from The Society of Thoracic Surgeons Adult Cardiac Surgery Database (version 2.81). Aortic dissections were excluded from the analysis. Multivariable logistic regression was used to adjust for 29 baseline and operative variables, including demographics, comorbidity, surgery, and nadir temperature, comparing outcomes according to protection strategy. The primary end point was a composite of 30-day and in-hospital mortality or major permanent neurologic complications. RESULTS: The rate of death or permanent neurologic complication was 10.9% (n = 850). Antegrade cerebral perfusion was most commonly used (n = 3369; 43%; median nadir temperature 23°C; median arrest time 30 minutes) compared with retrograde cerebral perfusion (n = 1898; 24%; 20°C; 24 minutes) and no cerebral perfusion (n = 2563; 33%; 20°C, 22 minutes). In multivariable analysis, deep hypothermia with antegrade (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.52 to 0.81) or retrograde (OR, 0.57; 95% CI, 0.45 to 0.71) perfusion and moderate hypothermia with antegrade perfusion (OR, 0.61; 95% CI, 0.46 to 0.79) were associated with significant reductions in death and stroke compared with deep hypothermia without cerebral perfusion. Risk reduction was greatest in circulatory arrest lasting longer than 30 minutes. CONCLUSIONS: For patients without aortic dissection and who require more than 30 minutes of circulatory arrest, optimal cerebral protection strategies are deep hypothermia with either antegrade or retrograde cerebral perfusion and moderate hypothermia with antegrade cerebral perfusion.

Antegrade selective cerebral perfusion reduced in-hospital mortality and permanent focal neurological deficit in patients with elective aortic arch surgery†.

OBJECTIVES: We retrospectively evaluated the outcome after elective aortic arch surgery with circulatory arrest to determine the impact of different brain protection strategies on neurological outcome and early and late survival. METHODS: A total of 925 patients were included. The patients were assigned to 2 groups based on the type of cerebral protection strategy used during circulatory arrest [hypothermic circulatory arrest (HCA) n = 224; antegrade selective cerebral perfusion (ASCP) n = 701]. The propensity score matching (1:1; 210 vs 210 patients) approach was used to minimize selection bias and to obtain comparable groups. RESULTS: The overall in-hospital mortality and permanent focal neurological deficit rates were 5.6% (n = 52) and 5.4% (n = 50) and were significantly lower in patients who received ASCP (4.4% and 3.4%, respectively) as compared to those who underwent HCA (9.4% and 11.6%, respectively) (P = 0.005 and P < 0.001). The propensity-matched analysis showed significantly lower rates of in-hospital mortality [3.8% vs 9.5% (HCA)] and permanent focal neurological deficit in ASCP group [2.9% vs 11.9% (HCA)]. Multivariable logistic regression analysis revealed left ventricular ejection fraction <30%, age >70 years, coronary artery disease, circulatory arrest time >40 min and mitral valve disease as independent predictors of in-hospital mortality. The use of ASCP was protective for early survival. Cox regression analysis revealed that long-term mortality was independently predicted by age, left ventricular ejection fraction <30%, total arch replacement, prior cardiac surgery, PVD, chronic obstructive pulmonary disease and previous stroke, whereas ASCP was protective for late survival. CONCLUSIONS: Elective aortic arch surgery is associated with acceptable early and late outcomes. The ASCP is associated with a significant reduction in-hospital mortality and occurrence of permanent neurological deficits.

Optimal Cerebral Protection Strategies in Aortic Surgery.

Cerebral protection strategies in aortic surgery have undergone significant evolution over the years, but its tenets remain rooted in maintenance of hypothermia and cerebral perfusion to limit adverse neurologic outcomes. While deep hypothermic circulatory arrest alone remains a viable approach in many instances, the need for prolonged duration of circulatory arrest and increasing case complexity have driven the utilization of adjunctive cerebral perfusion strategies. In this review, we present the most recent studies published on this topic over the last few years investigating the efficacy of deep hypothermic circulatory arrest, retrograde cerebral perfusion, and unilateral and bilateral antegrade cerebral perfusion, as well as the emerging trend toward mild and moderate HCA temperatures. We highlight the ongoing controversies in the field that underscore the need for large-scale randomized trials using well-defined neurologic endpoints to optimize evidence-based practice in cerebral protection.

A modified procedure in aortic arch replacement with no deep hypothermic circulatory arrest.

Deep hypothermia or circulation arrest is widely used during total aortic arch replacement. However, conventional procedures have high morbidity and mortality.1 We use the "branch-first" technique2,3 combined with clamping the distal aorta, incorporating a stented elephant trunk to avoid deep hypothermia and circulation arrest. This technique brings us closer to the goal of arch surgery without cerebral or visceral circulatory arrest and the morbidity of deep hypothermia. Early results are encouraging.

Predictors of Outcomes after Correction of Acute Type A Aortic Dissection under Moderate Hypothermic Circulatory Arrest and Antegrade Cerebral Perfusion.

INTRODUCTION: Hypothermic circulatory arrest is widely used for correction of acute type A aortic dissection pathology. We present our experience of 45 consecutive patients operated in our unit with bilateral antegrade cerebral perfusion and moderate hypothermic circulatory arrest. METHODS: Between January 2011 and April 2015, 45 consecutive patients were admitted for acute type A aortic dissection and operated emergently under moderate hypothermic circulatory arrest and bilateral antegrade cerebral perfusion. RESULTS: Mean age was 58±11.4 years old. Median circulatory arrest time was 41.5 (30-54) minutes while the 30-day mortality and postoperative permanent neurological deficits rates were 6.7% and 13.3%, respectively. Unadjusted analysis revealed that the factors associated with 30-day mortality were: preoperative hemodynamic instability (OR: 14.8, 95% CI: 2.41, 90.6, P=0.004); and postoperative requirement for open sternum management (OR: 5.0, 95% CI: 1.041, 24.02, P=0.044) while preoperative hemodynamic instability (OR: 8.8, 95% CI: 1.41, 54.9, P=0.02) and postoperative sepsis or multiple organ dysfunction (OR: 13.6, 95% CI: 2.1, 89.9, P=0.007) were correlated with neurological dysfunction. By multivariable logistic regression analysis, postoperative sepsis and multiple organ dysfunction independently predicted (OR: 15.9, 95% CI: 1.05, 96.4, P=0.045) the incidence of severe postoperative neurological complication. During median follow-up of 6 (2-12) months, the survival rate was 86.7%. CONCLUSION: Bilateral antegrade cerebral perfusion and direct carotid perfusion for cardiopulmonary bypass, in the surgical treatment for correction of acute aortic dissection type A, is a valuable technique with low 30-day mortality rate. However, postoperative severe neurological dysfunctions remain an issue that warrants further research.

Adjunct retrograde cerebral perfusion provides superior outcomes compared with hypothermic circulatory arrest alone: A meta-analysis.

OBJECTIVE: Retrograde cerebral perfusion is becoming less frequently used as a method of neuroprotection during aortic surgery. The present meta-analysis aims to compare outcomes after arch surgery with hypothermic circulatory arrest versus hypothermic circulatory arrest + retrograde cerebral perfusion. METHODS: Electronic searches were performed using 7 databases from their inception to September 2016. Relevant comparative studies that included patient groups who underwent aortic arch surgery using hypothermic circulatory arrest with continuous retrograde cerebral perfusion or hypothermic circulatory arrest alone were identified, and data were extracted by 2 independent researchers. Data were aggregated using a random-effects model per predefined clinical end points. RESULTS: Twenty-eight comparative studies were identified, with 2705 hypothermic circulatory arrest cases and 2817 hypothermic circulatory arrest + retrograde cerebral perfusion cases. No significant differences were seen between both groups in terms of age, gender, proportion of dissections and aneurysms, and hemiarch/total arch repair. The hypothermic circulatory arrest + retrograde cerebral perfusion group had slightly longer cardiopulmonary bypass time and lower body arrest time. Mortality was significantly increased for the hypothermic circulatory arrest cohort compared with the hypothermic circulatory arrest + retrograde cerebral perfusion cohort (odds ratio, 1.75; 95% confidence interval, 1.16-2.63; P = .007; I2 = 54%), but not on pooling of adjusted estimates. Stroke was also increased for the hypothermic circulatory arrest cohort (odds ratio, 1.50; 95% confidence interval, 1.07-2.10; P = .02; I2 = 29%). No difference in temporary neurologic deficit was identified (P = .66). Meta-regression found the treatment effect for mortality and stroke to be less pronounced in more contemporary series. CONCLUSIONS: These results suggest that the addition of retrograde cerebral perfusion during aortic arch surgery may provide better outcomes than using hypothermic circulatory arrest alone, although significant confounders exist. Further robust studies are required to confirm the utility of retrograde cerebral perfusion in arch surgery.

Use of extracorporeal bypass is associated with improved outcomes in open thoracic and thoracoabdominal aortic aneurysm repair.

OBJECTIVE: There is no consensus on the use or benefit of extracorporeal circulation (EC) during aneurysm repair of the descending thoracic aorta (DTA) or thoracoabdominal aorta (TAA). We evaluated the role of EC during DTA or TAA aneurysm repair using U.S. Medicare data. METHODS: Medicare (2004-2007) patients undergoing open repair of nonruptured DTA or TAA aneurysm were identified by International Classification of Diseases, Ninth Revision code. Specific exclusions included ascending aortic or arch repairs, concomitant cardiac procedures, and procedures employing deep hypothermic circulatory arrest. The impact of EC (code 3961) on early and late outcomes was analyzed using univariate analysis and multivariable regression. Survival was assessed using Kaplan-Meier analysis and Cox proportional hazards regression models. RESULTS: There were 4230 patients who had repair of intact DTA or TAA aneurysms, 2433 (57%) of which employed EC. Differences in baseline clinical features of EC and non-EC patients showed that patients undergoing aortic reconstruction with EC were older (73 ± 1 years vs 72 ± 1 years; P = .002), were more likely to be female (53% vs 47%; P < .001), and had more hypertension (56% vs 53%; P = .02); they had less chronic obstructive pulmonary disease (28% vs 34%; P < .0001), peripheral vascular disease (5.7% vs 11.3%; P < .001), and chronic kidney disease (7.7% vs 5.5%; P = .003). The 30-day mortality (9.7% for EC vs 12.2%; P = .02) and any major complication (49% for EC vs 58%; P < .001) were significantly reduced with EC use. EC use was associated with a shorter length of stay (13.5 ± 13 days vs 17.2 ± 18 days; P < .01) and lower total hospital charges ($151,000 ± 140,000 vs $180,000 ± 190,000; P < .01) compared with non-EC patients. EC patients were more likely to be discharged home instead of to an extended care facility (67% vs 56%; P < .01). Multivariable regression modeling to adjust for baseline clinical differences showed EC to independently reduce the risk of operative mortality (odds ratio [OR], 0.80; 95% confidence interval [CI], 0.65-0.97; P = .02), any complication (OR, 0.67; 95% CI, 0.59-0.76; P < .01), pulmonary complications (OR, 0.68; 95% CI, 0.59-0.79; P < .01), and acute renal failure (OR, 0.52; 95% CI, 0.44-0.61; P < .01). Long-term survival was higher (log-rank, P < .01) in EC patients at 1 year (81% ± 0.8% vs 73% ± 1%) and 5 years (67% ± 1% vs 52% ± 1%). Risk-adjusted Cox proportional hazards regression also showed that EC was independently associated with improved long-term survival (hazard ratio, 0.69; 95% CI, 0.63-0.74; P < .01). CONCLUSIONS: Although important clinical variables such as DTA or TAA aneurysm extent and spinal cord ischemic complications cannot be assessed with the Medicare database, EC use during open DTA and TAA aneurysm repair is associated with improved late survival and a significant reduction in operative mortality, morbidity, and procedural costs. These data indicate that EC should be a more widely applied adjunct in open DTA or TAA aneurysm repair.

Predictors of outcomes after correction of acute type a aortic dissection under moderate hypothermic circulatory arrest and antegrade cerebral perfusion

Abstract Introduction: Hypothermic circulatory arrest is widely used for correction of acute type A aortic dissection pathology. We present our experience of 45 consecutive patients operated in our unit with bilateral antegrade cerebral perfusion and moderate hypothermic circulatory arrest. Methods: Between January 2011 and April 2015, 45 consecutive patients were admitted for acute type A aortic dissection and operated emergently under moderate hypothermic circulatory arrest and bilateral antegrade cerebral perfusion. Results: Mean age was 58±11.4 years old. Median circulatory arrest time was 41.5 (30-54) minutes while the 30-day mortality and postoperative permanent neurological deficits rates were 6.7% and 13.3%, respectively. Unadjusted analysis revealed that the factors associated with 30-day mortality were: preoperative hemodynamic instability (OR: 14.8, 95% CI: 2.41, 90.6, P=0.004); and postoperative requirement for open sternum management (OR: 5.0, 95% CI: 1.041, 24.02, P=0.044) while preoperative hemodynamic instability (OR: 8.8, 95% CI: 1.41, 54.9, P=0.02) and postoperative sepsis or multiple organ dysfunction (OR: 13.6, 95% CI: 2.1, 89.9, P=0.007) were correlated with neurological dysfunction. By multivariable logistic regression analysis, postoperative sepsis and multiple organ dysfunction independently predicted (OR: 15.9, 95% CI: 1.05, 96.4, P=0.045) the incidence of severe postoperative neurological complication. During median follow-up of 6 (2-12) months, the survival rate was 86.7%. Conclusion: Bilateral antegrade cerebral perfusion and direct carotid perfusion for cardiopulmonary bypass, in the surgical treatment for correction of acute aortic dissection type A, is a valuable technique with low 30-day mortality rate. However, postoperative severe neurological dysfunctions remain an issue that warrants further research.

Favorable late survival after aortic surgery under straight deep hypothermic circulatory arrest.

BACKGROUND: Surgical and cerebral protection strategies in aortic arch surgery remain under debate. Perioperative results using deep hypothermic circulatory arrest (DHCA) have been associated with favorable short-term mortality and stroke rates. The present study focuses on late survival in patients undergoing aortic surgery using DHCA. METHODS: A total of 613 patients (mean age, 63.7 years) underwent aortic surgery between January 2003 and December 2015 using DHCA, with 77.3% undergoing hemiarch replacement and 20.4% undergoing arch replacement, with a mean DHCA duration of 29.7 ± 8.5 minutes (range, 10-62 minutes). We examined follow-up extending up to a mean of 3.8 ± 3.4 years (range, 0-14.1 years). RESULTS: Operative mortality was 2.9%, and the stroke rate was 2%. Survival was 92.2% at 1 year and 81.5% at 5 years, significantly lower than the values in an age- and sex-matched reference population. In elective, nondissection first-time surgeries (n = 424), survival was similar to that of the reference group. Acute type A aortic dissection (hazard ratio [HR], 4.84; P = .000), redo (HR, 4.12; P = .000), and descending aortic pathology (HR, 5.54: P = .000) were independently associated with reduced 1-year survival. Beyond 1 year, age (HR, 1.07; P = .000), major complications (HR, 3.11; P = .000), and atrial fibrillation (HR, 2.47; P = .006) were independently associated with poor survival. DHCA time was not significantly associated with survival in multivariable analysis. CONCLUSIONS: Aortic surgery with DHCA can be performed with favorable late survival, with the duration of DHCA period having only a limited impact. However, these results cannot be generalized for very long durations of DHCA (>50 minutes), when perfusion methods may be preferable. In elective, nondissection first-time surgeries, a late survival comparable to that in a reference population can be achieved. Early survival is adversely affected by aortic dissection, redo status, and disease extent.

The Risk of Neurological Dysfunctions after Deep Hypothermic Circulatory Arrest with Retrograde Cerebral Perfusion.

OBJECTIVE: Retrograde cerebral perfusion (RCP) is a brain protection technique that is adopted generally for anticipated short periods of deep hypothermic circulatory arrest (DHCA). However, the real impact of this technique on cerebral protection during DHCA remains a controversial issue. METHODS: For 344 (59.5%) of 578 consecutive patients (mean age, 66.9 ± 10.9 years) who underwent cardiovascular surgery under DHCA at the present authors' institution (1999-2015), RCP was the sole technique of cerebral protection that was adopted in addition to deep hypothermia. Surgery of the thoracic aorta was performed in 95.9% of these RCP patients; in 92 cases there was an aortic arch involvement. Outcomes were reviewed retrospectively. The focus was on postoperative neurological dysfunctions. RESULTS: There were 33 (9.6%) in-hospital deaths. Thirty-one (9%) patients had permanent neurological dysfunctions and 66 (19.1%) transitory neurological dysfunctions alone. Age older than 74 years (odds ratio [OR], 1.88, P = .023), surgery for acute aortic dissection (OR, 2.57; P = .0009), and DHCA time longer than 25 minutes (OR, 2.44; P = .0021) were predictors of neurological dysfunctions. The 10-year nonparametric estimate of freedom from all-cause death was 61.8% (95% confidence interval, 57.8%-65.8%). Permanent postoperative neurological dysfunctions were risk factors for cardiac or cerebrovascular death (hazard ratio, 2.6; P = .039) even after an adjusted survival analysis (P < .04). CONCLUSIONS: According to the study findings, RCP, in addition to deep hypothermia, combines with a low risk of neurological dysfunctions provided that DHCA length is 25 minutes or less. Permanent postoperative neurological dysfunctions are predictors of poor late survival.

Outcomes of Elective Aortic Hemiarch Reconstruction for Aneurysmal Disease in the Elderly.

BACKGROUND: This study evaluated outcomes of elective aortic hemiarch reconstruction for aneurysmal disease in the elderly. METHODS: Patients undergoing elective aortic hemiarch reconstruction for aneurysmal disease at a single institution between 2009 and 2014 were retrospectively reviewed. Patients were stratified into nonelderly (aged less than 75 years) versus elderly (aged 75 years or more). Outcomes included operative mortality and morbidity. RESULTS: In all, 629 patients (95 elderly; 15%) were included. Elderly patients had a greater comorbidity burden. Concomitant aortic valve replacement and coronary artery bypass were performed more frequently whereas root replacement was performed less frequently in the elderly. The overall stroke rate was 1.8% and was higher among the elderly (4.2% versus 1.3%, p = 0.05), although this difference no longer persisted after risk adjustment (odds ratio 2.54, p = 0.17). Median length of intensive care unit and hospital stay were longer in the elderly (64 versus 41 hours and 9 versus 7 days, respectively; each p < 0.001). Unadjusted and risk-adjusted operative mortality were similar (2.1% elderly versus 0.9% nonelderly, p = 0.32). Elderly patients were less frequently discharged to home (65% versus 95%, p < 0.001). Propensity matched analysis confirmed these findings. Moderate hypothermic circulatory arrest with antegrade cerebral perfusion was a safe strategy for the elderly patients, with stroke and operative mortality rates of 0% each. CONCLUSIONS: Although elderly patients have a more prolonged recovery after elective aortic hemiarch reconstruction for aneurysmal disease, outcomes are acceptable with low operative mortality and with the majority being discharged home. Moderate hypothermic circulatory arrest with antegrade cerebral perfusion is a safe strategy for this cohort. Advanced age alone should not be viewed as a contraindication in these cases.

Temperature Variation After Rewarming from Deep Hypothermic Circulatory Arrest Is Associated with Survival and Neurologic Outcome.

Therapeutic hypothermia is recommended by international guidelines after cardio-circulatory arrest. However, the effects of different temperatures during the first 24 hours after deep hypothermic circulatory arrest (DHCA) for aortic arch surgery on survival and neurologic outcome are undefined. We hypothesize that temperature variation after aortic arch surgery is associated with survival and neurologic outcome. In the period 2010-2014, a total of 210 consecutive patients undergoing aortic arch surgery with DHCA were included. They were retrospectively divided into three groups by median nasopharyngeal temperature within 24 hours after rewarming: hypothermia (<36°C; n = 65), normothermia (36-37°C; n = 110), and hyperthermia (>37°C; n = 35). Multivariate stepwise logistic and linear regressions were performed to determine whether different temperature independently predicted 30-day mortality, stroke incidence, and neurologic outcome assessed by cerebral performance category (CPC) at hospital discharge. Compared with normothermia, hyperthermia was independently associated with a higher risk of 30-day mortality (28.6% vs. 10.9%; odds ratio [OR] 2.8; 95% confidence interval [CI], 1.1-8.6; p = 0.005), stroke incidence (64.3% vs. 9.1%; OR 9.1; 95% CI, 2.7-23.0; p = 0.001), and poor neurologic outcome (CPC 3-5) (68.8% vs. 39.6%; OR 4.8; 95% CI, 1.4-8.7; p = 0.01). No significant differences were demonstrated between hypothermia and normothermia. Postoperative hypothermia is not associated with a better outcome after aortic arch surgery with DHCA. However, postoperative hyperthermia (>37°C) is associated with high stroke incidence, poor neurologic outcome, and increased 30-day mortality. Target temperature management in the first 24 hours after surgery should be evaluated in prospective randomized trials.

The impact of temperature in aortic arch surgery patients receiving antegrade cerebral perfusion for >30 minutes: How relevant is it really?

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.

Moderate hypothermia at warmer temperatures is safe in elective proximal and total arch surgery: Results in 665 patients.

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.

The Use of Hypothermic Circulatory Arrest During Heart Transplantation Does Not Worsen Posttransplant Survival.

BACKGROUND: Hypothermic circulatory arrest (HCA) has been used as an adjunct to cardiopulmonary bypass for decades, both electively and emergently, to facilitate a bloodless operative field while maintaining cerebral protection. The aim of this study is to determine the impact of HCA during heart transplantation on posttransplant outcomes. METHODS: All adult patients undergoing orthotopic heart transplantation at our institution between 2000 and 2012 were retrospectively reviewed. Patients were stratified based on need for HCA during surgery; patients who required HCA (HCA group, n = 25), and patients who did not (no-HCA group, n = 903). The primary outcomes of interest were 30-day and 1-year mortality and postoperative complication rate. RESULTS: Indications for HCA included control of significant hemorrhage (n = 9), need for distal aortic procedures (n = 9), or as an aid in difficult mediastinal dissection (n = 7). Mean duration of HCA was 22 ± 18 minutes at a mean temperature of 24.5° ± 5.5°C. Significantly more patients in the HCA group underwent transplant for congenital heart disease (16.0% HCA versus 2.8% no-HCA, p = 0.006), and patients in the HCA group had undergone more prior sternotomies (HCA 1 [interquartile range: 1 to 2] versus no-HCA 1 [interquartile range: 0 to 1], p < 0.001]. There was no statistical difference in 30-day mortality (8.0% HCA versus 4.2% no-HCA, p = 0.29) or 1-year mortality (8.0% HCA versus 12.3% no-HCA, p = 0.76). The HCA group had higher rates of reoperation for mediastinal bleeding and postoperative respiratory failure. CONCLUSIONS: The need for HCA during heart transplantation is rare but, when required, it is frequently a life-saving adjunct to cardiopulmonary bypass. However, patients who require HCA have higher rates of postoperative complications. Risk factors for needing HCA during transplantation include congenital heart disease and more than one prior sternotomies.

Surgical Treatment of Renal Cell Carcinoma With Cavoatrial Involvement: A Systematic Review of the Literature.

The treatment of renal cell carcinoma (RCC) with cavoatrial involvement represents a major surgical challenge. To date, many surgical strategies have been proposed. However, general agreement on the best approach does not yet exist. Deep hypothermic circulatory arrest (DHCA) is the most commonly used method and allows complete tumor resection without increasing operative risk. Cardiopulmonary bypass (CPB) without circulatory arrest and methods using no CBP were also proposed, without a clear evidence of superiority of 1 technique over the others. Further studies are needed to evaluate the possible role of alternative techniques compared with deep hypothermic circulatory arrest.

Moderate to Deep Hypothermia in Patients Undergoing Thoracoabdominal Aortic Repair.

BACKGROUND: The aim of this study was to determine early and mid-term outcomes after open repair of thoracoabdominal aortic aneurysm, with moderate to deep hypothermia as part of proximal aortic management. METHODS: Between April 2009 and March 2015, 44 patients underwent thoracoabdominal aortic repair by total cardiopulmonary bypass at our institute. Our strategy was to use deep (<25°C) hypothermic circulatory arrest when open proximal anastomosis is necessary (n = 18). Otherwise, proximal anastomosis with an aortic clamp was performed with moderate (25-30°C) hypothermia without circulatory arrest (n = 26). Early and mid-term outcomes were assessed in all patients. RESULTS: In-hospital mortality was observed in 1 patient (2.3%). Stroke was observed in 2 (4.5%) patients and a spinal cord ischemic injury in 4 (9.1%). Renal failure requiring new hemodialysis was observed in 5 patients (11.4%). There were 9 patients (20.5%) with early major adverse events (in-hospital death, stroke, spinal cord ischemic injury, renal failure requiring new hemodialysis, and prolonged intubation). Multivariable logistic regression analysis demonstrated that a history of abdominal aortic aneurysm repair (odds ratio 17.711, 95% confidence interval 1.274-246.426, P = 0.032) was the only independent predictor of early major adverse events. Deep hypothermic circulatory arrest was not an independent predictor of early major adverse events. At 5 years, overall freedom from death was 89.4 ± 6.1%. CONCLUSION: Moderate to deep hypothermia as a constituent of proximal aortic management was safe and effective in patients undergoing open repair of thoracoabdominal aortic aneurysm.