Type-A Aortic Dissection and Cerebral Perfusion: The Society of Thoracic Surgeons Database Analysis

Management of Acute Type A Aortic Dissection

This article reviews the management of acute type A aortic dissection (ATAAD), from initial temporizing medical therapy to the technical aspects of urgent surgical repair, which is the definitive treatment for ATAAD. Surgical repair and the extent of aortic resection and replacement are dictated by the location and extent of intimal tears, as well as aneurysmal dilation of the aorta. Cardiopulmonary bypass, hypothermic circulatory arrest, and cerebral perfusion are major considerations in management of this acute process. Several techniques pertinent to each portion of the involved aorta and relevant intraoperative management points are also discussed.

Future Paradigms of Aortic Dissection

Acute type A dissection remains a challenging disease to manage, which is associated with high morbidity and mortality both at presentation and in the chronic setting. This article reviews contemporary debates in operative management, summarizes the currently accepted standard of care, and explores the optimal extent of aortic repair given the high rate of long term aortic degeneration.

Cerebral Perfusion and Protection During Repair of Type A Dissection

Patients with the highest risk of neurologic injury after cardiac surgery are those undergoing repair of type A aortic dissections. Since the 1950s, extensive research has been conducted to improve the safety and neurologic outcomes of these patients. Surgeons now routinely use hypothermia with circulatory arrest, and adjunctive cerebral perfusion methods. This article highlights the historic development of modern cerebral perfusion and protection, and discusses technical details and clinical outcomes of cannulation strategies, temperature management, and antegrade cerebral perfusion and retrograde cerebral perfusion.

Long-term outcomes of total arch replacement with bilateral antegrade cerebral perfusion using the "arch first" approach

ObjectiveTo report outcomes of total arch replacement (TAR) with hypothermic circulatory arrest and bilateral antegrade cerebral perfusion (bACP) using an "arch first" approach for acute Type A aortic dissection (ATAAD). The "arch first" approach involved revascularization of the aortic arch branch vessels with uninterrupted ACP, before lower body circulatory arrest, while the patient was cooling.MethodsThis was an observational study of aortic surgeries from 2010 to 2021. All patients who underwent TAR with bACP for ATAAD were included. Short-term and long-term outcomes were reported utilizing descriptive statistics and Kaplan-Meier survival estimation.ResultsA total of 215 patients were identified who underwent TAR + bACP for ATAAD. Age was 59.0 [49.0-67.0] years and 35.3% were female. 73 patients (34.0%) underwent a concomitant aortic root replacement, 188 (87.4%) had aortic cannulation, circulatory arrest time was 37.0 [26.0-52.0] minutes, and nadir temperature was 20.8 [19.4-22.5] degrees Celsius. 35 patients (16.3%) had operative mortality (STS definition), 17 (7.9%) had a new stroke, 79 (36.7%) had prolonged mechanical ventilation (>24 h), 35 (16.3%) had acute renal failure (by RIFLE criteria), and 128 (59.5%) had blood product transfusions. One-year survival was 77.1%, while 5-years survival was 67.1%. During follow-up, there were 23 (10.7%) reinterventions involving the descending thoracic aorta - either thoracic endovascular aortic repair or open thoracoabdominal aortic replacement.ConclusionsAmong patients with ATAAD, short-term postoperative outcomes after TAR + bACP using the "arch first" approach are acceptable. Moreover, this operative strategy may furnish long-term durability, with a reasonably low reintervention rate and satisfactory overall survival.

Does Higher Temperature During Moderate Hypothermic Circulatory Arrest Increase the Risk of Paraplegia in Acute DeBakey I Aortic Dissection Patients?

BACKGROUND

In this study, we sought to assess the safety of high-moderate (24.1-28.0°C) and low-moderate (20.1-24.0°C) systemic hypothermia during circulatory arrest (MHCA) in patients with acute DeBakey I aortic dissection (DeBakey I AAD), particularly concerning spinal cord protection.

METHODS

From 2009 to 2020, 1759 patients with DeBakey I AAD who underwent frozen elephant trunk and total arch replacement surgery at a tertiary centre were divided into preoperative malperfusion (viscera, spinal cord, or lower extremities) and nonmalperfusion subgroups. The baseline differences were balanced with the use of propensity score matching. Prognoses were compared between those who were subjected to high-MHCA (nasopharyngeal temperature 24.1-28.0°C) and low-MHCA (nasopharyngeal temperature 20.1-24.0°C).

RESULTS

In the nonmalperfusion subgroup (n = 1389), 469 pairs of matched patients showed lower in-hospital mortality and incidence of acute kidney injury in the high-MHCA group than in the low-MHCA group: in-hospital mortality 7.0% vs 10.2% (P = 0.01); acute kidney injury, 57.1% vs 64.6% (P < 0.01). The duration of mechanical ventilation was shorter in the high-MHCA group than that in the low-MHCA group (P = 0.03). No significant difference in the incidence of paraplegia was observed between the 2 groups. In the malperfusion subgroup (n = 370), 112 pairs of matched patients showed a higher incidence of paraplegia in the high-MHCA group than in the low-MHCA group (15.9% vs 6.5%; P = 0.04).

CONCLUSIONS

The safety of high-MHCA, a commonly used temperature management strategy during aortic arch surgery, was recognised in most patients with DeBakey I AAD. However, among patients with preoperative distal organ malperfusion, low-MHCA may be more appropriate owing to an increased risk of postoperative paraplegia associated with high-MHCA.

Effectiveness of an integrated cerebral protection protocol in type A aortic dissection surgery: an inverse probability treatment weighting analysis

BACKGROUND

Cerebral protection strategies in type A aortic dissection (TAAD) surgery are critical yet inconclusive. We propose an integrated cerebral protection protocol. This study aimed to evaluate the effectiveness of this protocol.

METHODS

From January 2020 to December 2022, 85 patients were treated with an integrated protocol incorporating bilateral antegrade cerebral perfusion (ACP) and moderate hypothermia, with measures to prevent the shedding of thrombus or endothelial debris (BACP group), while traditional protocols were applied to 273 additional patients (UACP group). Inverse probability treatment weighting (IPTW) was performed to balance baseline characteristics. Three logistic regression models were used to evaluate the relationship between the two cerebral protection strategies and neurologic complications. Stepwise logistic regression was further employed to identify risk factors for cerebral complications.

RESULTS

Baseline characteristics were balanced after IPTW adjustment. The BACP group had a significantly shorter operative time (364.79 vs. 397.61 min, P = 0.022), significantly fewer neurologic complications (5.6% vs. 15.9%, P = 0.032), and transient neurologic injury (3.0% vs. 12.5%, P = 0.035). Binary multivariable logistic regression analysis showed that the cerebral complication risk was 3.14 times greater with the traditional protocol compared to the integrated protocol (odds ratio[OR]:3.14, 95%confidence interval[CI]:1.19-8.27, P = 0.020). Stepwise logistic regression confirmed that cerebral complications were dramatically increased with unilateral ACP (OR:2.99, 95%CI:1.14-7.82, P = 0.025), while bilateral ACP had a significant impact on decreasing cerebral complications.

CONCLUSIONS

Our integrated protocol effectively minimizes postoperative cerebral complications. Moderate hypothermia combined with BACP and measures to prevent brain debris could be adopted as an effective strategy for cerebral protection in TAAD surgery.

A comprehensive organ protection strategy in total arch replacement: a propensity-weighted analysis

OBJECTIVES

The goal was to report the outcomes and determine the effectiveness of a comprehensive organ protection strategy in total arch replacement.

METHODS

A total of 350 patients who underwent total arch replacement were enrolled. Fifty-four patients underwent the comprehensive organ protection strategy with bilateral antegrade cerebral perfusion and the aortic balloon occlusion technique (comprehensive strategy group); 296 patients underwent the standard strategy with unilateral antegrade cerebral perfusion (standard strategy group). Inverse probability of treatment weighting was used to balance the baseline characteristics.

RESULTS

After inverse probability of treatment weighting, the comprehensive strategy group had lower incidences of 30-day mortality (0.9% vs 4.9%, P = 0.002), continuous renal replacement therapy (0.6% vs 10.3%, P < 0.001), renal failure (4.6% vs 13.7%, P < 0.001), hepatic dysfunction (11.6% vs 21.1%, P = 0.001) and shorter duration of mechanical ventilation [16 (13, 31) vs 20 (14, 48) h, P = 0.011]. Multivariable logistic analysis showed that the comprehensive strategy was an independent protective factor of 30-day mortality [odds ratio (OR): 0.242, 95% confidence interval (CI): 0.068-0.867, P = 0.029], continuous renal replacement therapy (OR: 0.045, 95% CI: 0.008-0.264, P = 0.001), renal failure (OR: 0.351, 95% CI: 0.156-0.788, P = 0.011) and mechanical ventilation >20 h (OR: 0.531, 95% CI: 0.319-0.883, P = 0.015). Kaplan-Meier analysis showed that mid-term survival was comparable.

CONCLUSIONS

The comprehensive organ protection strategy might improve early survival, reduce the use of continuous renal replacement therapy, have protective effects on the kidney and shorten mechanical ventilation time in total arch replacement. This strategy might be considered a viable alternative in total arch replacement.

Advances and Innovation in Acute Type a Aortic Dissection

The prompt and appropriate management of acute type A aortic dissections is imperative for patient survival. Advances in medical technology have broadened the adjuncts available to treat the spectrum of pathology within this population. The role of medical management prior to surgical intervention and the components of operative management, including cannulation strategies, neuroprotection, and the extent of aortic intervention, have been explored in-depth within the literature. More recent work has identified novel open and endovascular techniques available to treat acute type A dissections. This review aims to summarize the literature, with a particular focus on innovation in cardiac surgery and its role in the care of this high-risk population.

Contemporary comparative surgical outcomes of type A aortic dissection in US and China: an analysis of the national inpatient sample database and a Chinese multi-institutional registry

BACKGROUND

To investigate the contemporary comparative inpatient prognosis among US and Chinese patients with type A aortic dissection (TAAD).

METHODS

Data from Chinese multi-institutional TAAD registry and the US National Inpatient Sample databases were analyzed. We used multivariable logistic regression models to compare in-hospital mortality and perioperative complication rates between the US and China. Length of stay and overall costs were fitted with quantile regression models. Independent prognostic factors associated with post-operative survival were assessed via Cox proportional hazards models.

RESULTS

Among 3,121 eligible TAAD patients, 1,073 were from China (25.0% female; mean ± SD age, 53.9 ± 12.4) and 2,048 were from the US (31.2% female; mean ± SE age, 59.8 ± 0.3). During the study period, the in-hospital mortality rates in China and the US were 15.5% and 13.3%, yet the difference was insignificant after adjustment (aOR, 1.16; 95% CI, 0.69-1.97). While there was no significant difference in overall perioperative complications (aOR, 1.07; 95% CI, 0.52-2.18), the patterns of complications differed between two cohorts. While Chinese TAAD patients experienced significantly longer duration of hospitalization (median difference, + 10.4 days; 95% CI, 9.2-11.5), the US TAAD cohort had significantly greater overall hospitalization costs (49.9; 95% CI, 55.4-44.5, in 1000 USD).

CONCLUSIONS

Notwithstanding significant differences in demographic and clinical characteristics, TAAD patients from China and the US demonstrated comparable in-hospital mortality and overall perioperative complication rates. Future initiatives should focus on expanding surgical eligibility to the elderly Chinese TAAD patients and optimizing the duration of hospitalization without undermining meaningful clinical outcomes.

TRIAL REGISTRATION

KY20220425-05, April 5th 25 2022.

Moderate hypothermia circulatory arrest as a brain-protective strategy for type A aortic dissection

OBJECTIVES

Brain-protective strategies for acute type A aortic dissection (TAAD) remain controversial. Moderate hypothermia circulatory arrest (MHCA) without cerebral perfusion is not commonly used. However, we aimed to assess its safety and efficacy in 358 patients who underwent hemiarch replacement with MHCA for acute type A aortic dissection at our institution from August 2012 to August 2022.

METHODS

Clinical outcomes were compared according to circulatory arrest time [≤15 min (S group, n = 52) vs ≥16 min (L group, n = 306)]. The primary outcome was postoperative stroke.

RESULTS

The S group had more older patients (72.5 vs 68.8 years; P = 0.04), a greater incidence of carotid artery malperfusion (21% vs 11%; P = 0.043) and a lower body mass index (21.7 vs 23.6 kg/m2; P < 0.01) and hemodynamic instability (3.8% vs 16%; P = 0.02) than the L group. The incidence of postoperative stroke (7.7% vs 12%; P = 0.33) and the rate of 30-day mortality (5.8% vs 6.5%; P = 0.83) did not significantly differ between groups. After adjusting for all potential confounding factors pre- and intraoperatively, there was no significant difference in postoperative outcomes between groups.

CONCLUSIONS

MHCA alone for TAAD had comparable postoperative outcomes with circulatory arrest times under and over 15 min. However, longer arrest times were associated with a higher risk of stroke.

Reoperative total arch replacement after previous cardiovascular surgery: Outcomes in 426 consecutive patients

OBJECTIVE

Total aortic arch replacement (TAR) after previous cardiovascular surgery is technically challenging and is becoming more frequent as outcomes for primary arch repair have improved. primary. We analyzed outcomes of reoperative compared with first-time TAR.

METHODS

The institutional aortic database was queried to identify consecutive patients undergoing TAR between 1997 and 2022. In total, 426 patients underwent TAR, of whom 150 (35%) had previous cardiovascular surgery (reop TAR) and 276 (65%) underwent their first cardiovascular operation.

RESULTS

The reop TAR group was younger (61 ± 13 vs 71 ± 11, P < .001) with more comorbidities such as ischemic heart disease (12% vs 4.3%, P = .006), previous stroke (36% vs 14.5%, P < .001), and renal impairment (24% vs 12.7%, P = .004). Reop TAR had longer cardiac ischemic times (119.3 ± 45.5 minutes vs 98 ± 31.9 minutes, P < .001), a greater operative mortality (3.3% vs 0.4%, P = .040), and incurred a 4-fold increased risk of major adverse event (95% confidence interval [CI], 1.41-11.49, P = .009). Ten-year survival was also lower in the reop TAR cohort (76% vs 82.2%; hazard ratio, 1.79; 95% CI, 1.12-2.86, P = .015) and there was greater need for late reinterventions, mainly on the downstream aorta (hazard ratio, 1.29; 95% CI, 1.03-1.62, P = .024).

CONCLUSIONS

Reop TAR is a technically challenging operation and is associated with increased operative mortality and adverse events. Gratifying results can be obtained with meticulous surgical planning and focused attention on end-organ protection. Late reinterventions occur in a significantly greater percentage of patients undergoing reop TAR, and future studies should focus attention on identifying those at-risk groups who may benefit from a more aggressive index procedure.

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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 ± 16 mg/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 ± 1008 pg/mL, p < 0.001) at 24 h 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 ± 3 days, p < 0.001).

CONCLUSIONS

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.

Cerebral Protection Strategies in Aortic Arch Surgery-Past Developments, Current Evidence, and Future Innovation

Surgery of the aortic arch remains a complex procedure, with neurological events such as stroke remaining its most dreaded complications. Changes in surgical technique and the continuous innovation in neuroprotective strategies have led to a significant decrease in cerebral and spinal events. Different modes of cerebral perfusion, varying grades of hypothermia, and a number of pharmacological strategies all aim to reduce hypoxic and ischemic cerebral injury, yet there is no evidence indicating the clear superiority of one method over another. While surgical results continue to improve, novel hybrid and interventional techniques are just entering the stage and the question of optimal neuroprotection remains up to date. Within this perspective statement, we want to shed light on the current evidence and controversies of cerebral protection in aortic arch surgery, as well as what is on the horizon in this fast-evolving field. We further present our institutional approach as a large tertiary aortic reference center.

Classification of the Urgency of the Procedure and Outcome of Acute Type A Aortic Dissection

Surgery for type A aortic dissection (TAAD) is associated with a high risk of early mortality. The prognostic impact of a new classification of the urgency of the procedure was evaluated in this multicenter cohort study. Data on consecutive patients who underwent surgery for acute TAAD were retrospectively collected in the multicenter, retrospective European Registry of TAAD (ERTAAD). The rates of in-hospital mortality of 3,902 consecutive patients increased along with the ERTAAD procedure urgency grades: urgent procedure 10.0%, emergency procedure grade 1 13.3%, emergency procedure grade 2 22.1%, salvage procedure grade 1 45.6%, and salvage procedure grade 2 57.1% (p <0.0001). Preoperative arterial lactate correlated with the urgency grades. Inclusion of the ERTAAD procedure urgency classification significantly improved the area under the receiver operating characteristics curves of the regression model and the integrated discrimination indexes and the net reclassification indexes. The risk of postoperative stroke/global brain ischemia, mesenteric ischemia, lower limb ischemia, dialysis, and acute heart failure increased along with the urgency grades. In conclusion, the urgency of surgical repair of acute TAAD, which seems to have a significant impact on the risk of in-hospital mortality, may be useful to improve the stratification of the operative risk of these critically ill patients. This study showed that salvage surgery for TAAD is justified because half of the patients may survive to discharge.

Current Knowledge on the Interaction of Human Cytomegalovirus Infection, Encoded miRNAs, and Acute Aortic Syndrome

Aortic dissection is a clinicopathological entity caused by rupture of the intima, leading to a high mortality if not treated. Over time, diagnostic and investigative methods, antihypertensive therapy, and early referrals have resulted in improved outcomes according to registry data. Some data have also emerged from recent studies suggesting a link between Human Cytomegalovirus (HCMV) infection and aortic dissection. Furthermore, the use of microRNAs has also become increasingly widespread in the literature. These have been noted to play a role in aortic dissections with elevated levels noted in studies as early as 2017. This review aims to provide a broad and holistic overview of the role of miRNAs, while studying the role of HCMV infection in the context of aortic dissections. The roles of long non-coding RNAs, circular RNAs, and microRNAs are explored to identify changes in expression during aortic dissections. The use of such biomarkers may one day be translated into clinical practice to allow early detection and prognostication of outcomes and drive preventative and therapeutic options in the future.

Lactate-Based Difference as a Determinant of Outcomes following Surgery for Type A Acute Aortic Dissection: A Multi-Centre Study

Type A acute aortic dissection (TAAAD) is a serious condition within the acute aortic syndromes that demands immediate treatment. Despite advancements in diagnostic and referral pathways, the survival rate post-surgery currently sits at almost 20%. Our objective was to pinpoint clinical indicators for mortality and morbidity, particularly raised arterial lactate as a key factor for negative outcomes.

METHODS

All patients referred to the three cardiovascular centres between January 2005 and December 2022 were included in the study. The inclusion criteria required the presence of a lesion involving the ascending aorta, symptoms within 7 days of surgery, and referral for primary surgical repair of TAAAD based on recommendations, with consideration for other concomitant major cardiac surgical procedures needed during TAAAD and retrograde extension of TAAAD. We conducted an analysis of both continuous and categorical variables and utilised predictive mean matching to fill in missing numeric features. For missing binary variables, we used logistic regression to impute values. We specifically targeted early postoperative mortality and employed LASSO regression to minimise potential collinearity of over-fitting variables and variables measured from the same patient.

RESULTS

A total of 633 patients were recruited for the study, out of which 449 patients had complete preoperative arterial lactate data. The average age of the patients was 64 years, and 304 patients were male (67.6%). The crude early postoperative mortality rate was 24.5% (110 out of 449 patients). The mortality rate did not show any significant difference when comparing conservative and extensive surgeries. However, malperfusion had a significant impact on mortality [48/131 (36.6%) vs. 62/318 (19.5%), p < 0.001]. Preoperative arterial lactates were significantly elevated in patients with malperfusion. The optimal prognostic threshold of arterial lactate for predicting early postoperative mortality in our cohort was ≥2.6 mmol/L.

CONCLUSION

The arterial lactate concentration in patients referred for TAAAD is an independent factor for both operative mortality and postoperative complications. In addition to mortality, patients with an upper arterial lactate cut-off of ≥2.6 mmol/L face significant risks of VA ECMO and the need for dialysis within the first 48 h after surgery. To improve recognition and facilitate rapid transfer and surgical treatment protocol, more diligent efforts are required in the management of malperfusion in TAAAD.

Radiological properties of neurological injury following acute type A aortic dissection repair

Objective

The study objective was to assess the radiological properties of acute type A aortic dissection-related neurological injuries and identify predictors of neurological injury.

Methods

Our single-center, retrospective, observational study included all patients who underwent acute type A aortic dissection repair between January 1998 and December 2021. Multivariable analyses and Cox regression were performed to identify predictors of embolic lesions, watershed lesions, neurological injury, 30-day mortality, and late mortality.

Results

A total of 538 patients were included. Of these, 120 patients (22.3%) experienced postoperative neurological injury; 74 patients (13.8%) had postoperative stroke, and 36 patients (6.8%) had postoperative coma. The 30-day mortality was 22.7% in the neurological injury group versus 5.8% in the no neurological injury group (P < .001). We identified several independent predictors of neurological injury. Cerebral malperfusion (odds ratio, 2.77; 95% confidence interval, 1.53-5.00), systemic hypotensive shock (odds ratio, 1.97; 95% confidence interval, 1.13-3.43), and aortic arch replacement (odds ratio, 3.08; 95% confidence interval, 1.17-8.08) predicted embolic lesions. Diabetes mellitus (odds ratio, 5.35; 95% confidence interval, 1.85-15.42), previous cardiac surgery (odds ratio, 8.62; 95% confidence interval, 1.47-50.43), duration of hypothermic circulatory arrest (odds ratio, 1.05; 95% confidence interval, 1.01-1.08), cardiopulmonary bypass time (odds ratio, 1.01; 95% confidence interval, 1.00-1.01), ascending aortic/arch cannulation (odds ratio, 5.68; 95% confidence interval, 1.88-17.12), and left ventricular cannulation (odds ratio, 17.81; 95% confidence interval, 1.69-188.01) predicted watershed lesions. Retrograde cerebral perfusion (odds ratio, 0.28; 95% confidence interval, 0.01-0.84) had a protective effect against watershed lesions.

Conclusions

In this study, we demonstrated that the radiological features of neurological injury may be as important as clinical characteristics in understanding the pathophysiology and causality behind neurological injury related to acute type A aortic dissection repair.

Surgical Strategy for the Repair of Acute Type A Aortic Dissection: A Multicenter Study

Type A acute aortic dissection is associated with significant morbidity and mortality, with prompt referral imaging and management to tertiary referral centers needed urgently. Surgery is usually needed emergently, but the choice of surgery often varies depending on the patient and the presentation. Staff and center expertise also play a major role in determining the surgical strategy employed. The aim of this study was to compare the early- and medium-term outcomes of patients undergoing a conservative approach extended only to the ascending aorta and the hemiarch to those of patients subjected to extensive surgery (total arch reconstruction and root replacement) across three European referral centers. A retrospective study was conducted across three sites between January 2008 and December 2021. In total, 601 patients were included within the study, of which 30% were female, and the median age was 64.4 years. The most common operation was ascending aorta replacement (n = 246, 40.9%). The aortic repair was extended proximally (i.e., root n = 105; 17.5%) and distally (i.e., arch n = 250; 41.6%). A more extensive approach, extending from the root to the arch, was employed in 24 patients (4.0%). Operative mortality occurred in 146 patients (24.3%), and the most common morbidity was stroke (75, 12.6%). An increased length of ICU admission was noted in the extensive surgery group, which comprised younger and more frequently male patients. No significant differences were noted in surgical mortality between patients managed with extensive surgery and those managed conservatively. However, age, arterial lactate levels, "intubated/sedated" status on arrival, and "emergency or salvage" status at presentation were independent predictors of mortality both within the index hospitalization and during the follow-up. The overall survival was similar between the groups.

Sex-Based Difference in Aortic Dissection Outcomes: A Multicenter Study

BACKGROUND

Type A Acute Aortic Dissection (TAAAD) repair is a surgical emergency associated with high morbidity and mortality. Registry data have noted several sex-specific differences in presentation with TAAAD which may account for the differences in men and women undergoing surgery for this condition.

METHODS

A retrospective review of data from three departments of cardiac surgery (Centre Cardiologique du Nord, Henri-Mondor University Hospital, San Martino University Hospital, Genoa) between January 2005 and 31 December 2021 was conducted. Confounders were adjusted using doubly robust regression models, a combination of regression models with inverse probability treatment weighting by propensity score.

RESULTS

633 patients were included in the study, of which 192 (30.3%) were women. Women were significantly older with reduced haemoglobin levels and pre-operative estimated glomerular filtration rate compared to men. Male patients were more likely to undergo aortic root replacement and partial or total arch repair. Operative mortality (OR 0.745, 95% CI: 0.491-1.130) and early postoperative neurological complication results were comparable between the groups. The adjusted survival curves using IPTW by propensity score confirmed the absence of a significant impact of gender on long-term survival (HR 0.883, 95% CI 0.561-1.198). In a subgroup analysis of women, preoperative levels of arterial lactate (OR 1.468, 95% CI: 1.133-1.901) and mesenteric ischemia after surgery (OR 32.742, 95% CI: 3.361-319.017) were significantly associated with increased operative mortality.

CONCLUSIONS

The advancing age of female patients alongside raised preoperative level of arterial lactate may account for the increasing preponderance among surgeons to perform more conservative surgery compared to their younger male counterparts although postoperative survival was similar between the groups.

Cerebral Protection Strategies and Stroke in Surgery for Acute Type A Aortic Dissection

Background: Perioperative stroke remains a devastating complication in the operative treatment of acute type A aortic dissection. To reduce the risk of perioperative stroke, different perfusion techniques can be applied. A consensus on the preferred cerebral protection strategy does not exist. Methods: To provide an overview about the different cerebral protection strategies, literature research on Medline/PubMed was performed. All available original articles reporting on cerebral protection in surgery for acute type A aortic dissection and neurologic outcomes since 2010 were included. Results: Antegrade and retrograde cerebral perfusion may provide similar neurological outcomes while outperforming deep hypothermic circulatory arrest. The choice of arterial cannulation site and chosen level of hypothermia are influencing factors for perioperative stroke. Conclusions: Deep hypothermic circulatory arrest is not recommended as the sole cerebral protection technique. Antegrade and retrograde cerebral perfusion are today’s standard to provide cerebral protection during aortic surgery. Bilateral antegrade cerebral perfusion potentially leads to superior outcomes during prolonged circulatory arrest times between 30 and 50 min. Arterial cannulation sites with antegrade perfusion (axillary, central or carotid artery) in combination with moderate hypothermia seem to be advantageous. Every concept should be complemented by adequate intraoperative neuromonitoring.

Unilateral versus bilateral antegrade cerebral perfusion during surgical repair for patients with acute type A aortic dissection

Objectives

To compare unilateral versus bilateral antegrade cerebral perfusion (ACP) techniques on cerebral protection during acute type A aortic dissection repair.

Methods

Using an institutional database, we retrospectively reviewed patients who underwent acute type A aortic dissection repair with selective ACP techniques from October 2008 to December 2019. Primary end point was the detection of neurologic dysfunctions. The secondary end point was mortality. For baseline adjustment, the propensity score matching method was used. Multivariable logistic regression analysis was performed to determine the predictor of neurologic events.

Results

Among 522 patients (aged 62.0 ± 14.9 years; 45.7% women), unilateral and bilateral ACP techniques were used in 357 (64.7%) and 165 (35.3%) patients, respectively. Transient (19.6% vs 21.2%; P = .65) and permanent (7.0% vs 10.3%; P = .70) neurologic dysfunction rates were not significantly different in patients with unilateral versus bilateral ACP, respectively. Observed mortality rate was higher in the patients with bilateral ACP (hazard ratio, 2.05; 95% CI, 1.33-3.14; P = .001). Propensity-score matching yielded 94 pairs of patients. In matched analysis, bilateral ACP did not significantly lower the risks for transient (odds ratio, 0.87; 95% CI, 0.42-1.81; P = .71) and permanent (odds ratio, 1.42; 95% CI, 0.55-3.85; P = .47) neurologic dysfunction or death (hazard ratio, 1.65; 95% CI, 0.87-3.15; P = .13). In the multivariable analysis, the ACP technique was not significantly associated with perioperative neurologic deficit.

Conclusions

Despite additional supply, the patients undergoing bilateral ACP during acute type A aortic dissection repair did not have superior outcomes in neurologic and death events compared with the patients undergoing unilateral ACP.

Cerebral protection using deep hypothermic circulatory arrest versus retrograde cerebral perfusion for aortic hemiarch reconstruction

BACKGROUND

With evolutions in technique, recent data encourage the use of cerebral perfusion during aortic arch repair. However, a randomized data have demonstrated higher rates of neurologic injury according to MRI lesions using antegrade cerebral perfusion during hemiarch reconstruction.

METHODS

This was a retrospective review of two institutional aortic center databases to identify adult patients who underwent aortic hemiarch reconstruction for elective aortic aneurysm or acute type A aortic dissection. Patients were stratified according to cerebral protection method: (1) deep hypothermic circulatory arrest (DHCA) group versus (2) DHCA/retrograde cerebral perfusion (RCP) group.

RESULTS

A total of 320 patients and 245 patients underwent hemiarch reconstruction for aortic aneurysm electively and aortic dissection, respectively. In aneurysmal pathology, the DHCA group included 133 patients and the DHCA/RCP group included 187 patients. Operative mortality was 0.8% in the DHCA group and 2.7% in the DHCA/RCP group (p = 0.41). Kaplan-Meier survival estimates revealed comparable 2-year survival (p = 0.14). In dissection, 43 patients and 202 patients were included in the DHCA group and the DHCA/RCP group, respectively. Operative mortality was equivalent between the two groups (11.6% in the DHCA group and 9.4% in the DHCA/RCP group, p = 0.58). Long-term survival was similar at 2 years between the groups (p = 0.06). Multivariable analysis showed cerebral perfusion strategy was not associated with the composite outcome of operative mortality and stroke.

CONCLUSIONS

In treating both elective and acute ascending aortic pathologies with hemiarch reconstruction, both DHCA alone or in combination with RCP yield comparable results.

Does deep hypothermic circulatory arrest with versus without retrograde cerebral perfusion affect the outcomes after proximal aortic arch aneurysm and acute type A aortic dissection repair? Different pathologies and cerebral protection techniques with similar results

Hypothermic circulatory arrest is used for proximal and total aortic arch correction in patients with aortic arch aneurysm and acute or chronic type A aortic dissection. Different cerebral perfusion techniques have been proposed for reducing morbidity and mortality rate. The study of Arnaoutakis et al. showed that deep hypothermic circulatory arrest with or without retrograde cerebral perfusion for proximal aortic aneurysm and acute type A aortic dissection correction had similar results with regard to morbidity and mortality rate. In addition, the short circulatory arrest time contributes for favorable outcomes of these patients. Although antegrade cerebral perfusion with hypothermic circulatory is widely used by many cardiac surgeons, deep hypothermic circulatory arrest with or without retrograde cerebral perfusion remains an alternative and safe method for brain protection in patients undergoing proximal aortic arch aneurysm or acute type A aortic dissection repair.

Matched comparison of 3 cerebral perfusion strategies in open zone-0 anastomosis for acute type A aortic dissection

OBJECTIVES

The present study aims to investigate outcomes after the surgical treatment of acute type A aortic dissection in regard to three available selective cerebral perfusion strategies.

METHODS

From 2000 to 2019, patients were selected based on the employment of either retrograde cerebral perfusion (RCP), unilateral antegrade cerebral perfusion (uACP) or bilateral antegrade cerebral perfusion (bACP) during open zone-0 anastomosis. Propensity score TriMatch analysis considering several preoperative and intraoperative variables was used to identify well-balanced triplets. The primary end point of the study was a new cerebral operation-related neurologic deficit.

RESULTS

Operative times (operation time, cardiopulmonary bypass time, reperfusion time) were significantly longer in the RCP group, in which deeper hypothermia was applied (27.5 [24-28], 28 [26-28] and 16 [16-17]°C for uACP, bACP and RCP, respectively, P-value <0.001). The RCP group showed higher red blood cell concentrates and fresh frozen plasma transfusion rates. No significant difference of new cerebral operation-related neurologic deficit was observed between the 3 groups (12.9% vs 12.9% vs 11.3% for RCP, uACP and bACP, P-value = 0.86). In addition, 30-day mortality showed similar distribution independently of the cerebral perfusion strategy adopted (17.7% vs 14.5% vs 17.7% for RCP, uACP and bACP, P-value = 0.86).

CONCLUSIONS

However, based on a small sample size, the comparison showed no relevant differences in terms of neurologic outcome and 30-day mortality, confirming RCP, uACP and bACP as safe and reproducible selective cerebral perfusion strategies in surgery for acute type A aortic dissection.

Aortic Balloon Occlusion Technique Does Not Improve Peri-Operative Outcomes for Acute Type A Acute Aortic Dissection Patients With Lower Body Malperfusion

Background

The management of malperfusion is vital to improve the outcomes of surgery for acute type A acute aortic dissection (ATAAD). Open arch repair under hypothermic circulatory arrest with selective antegrade cerebral perfusion (HCA/sACP) is safe and efficient but associated with inevitable hypothermia and ischemia-reperfusion injury. The aortic balloon occlusion (ABO) technique is shown to be organ protective by allowing higher temperature and shorter circulatory arrest time. In this study, we aimed to evaluate the safety and efficacy of this new technique for ATAAD patients with lower body malperfusion.

Methods

Between January 2013 and November 2020, 355 ATAAD patients with lower body malperfusion who underwent arch repair in our institute were enrolled. The patients were divided into 2 groups: ABO group (n = 85) and HCA/sACP group (n = 271). Propensity score matching was performed to correct baseline differences.

Results

Using the propensity score matching, 85 pairs were generated. Circulatory arrest time was significantly lower in the ABO group compared with the HCA/sACP group (median, 8 vs. 22 min; p < 0.001). The incidence of in-hospital mortality (10.6 vs. 12.9%; p = 0.812), stroke (7.1 vs. 7.1%; p = 1.000), dialysis (25.9 vs. 32.9%; p = 0.183), hepatic dysfunction (52.9 vs. 57.6%; p = 0.537), tracheostomy (4.7 vs. 2.4%; p = 0.682), paraplegia (1.2 vs. 4.7%; p = 0.368) were comparable between ABO and HCA/sACP groups. Other outcomes and major adverse events were comparable. The multivariable logistic analysis did not recognize ABO technique protective against any major adverse outcomes.

Conclusions

For ATAAD patients with lower body malperfusion, the ABO technique allows the performance of arch repair with frozen elephant trunk (FET) under higher temperature and shorter circulatory arrest time. However, ABO technique did not improve perioperative outcomes. Future studies are warranted to evaluate the efficacy of this technique.

Association between Duration of Deep Hypothermic Circulatory Arrest and Surgical Outcome in Patients with Acute Type A Aortic Dissection: A Large Retrospective Cohort Study

(1) Background: Deep hypothermic circulatory arrest (DHCA) with selective antegrade cerebral perfusion (ACP) is an established cerebral protection technique for the conduction of complex surgical procedures involving the aortic arch. It is controversial whether the duration of DHCA is associated with adverse outcome in patients with acute type A aortic dissection (AAAD). Our goal was to investigate whether DHCA time was associated with surgical outcome in patients undergoing a surgical treatment of AAAD. (2) Methods: A total of 410 patients were divided into two groups based on the DHCA time less than 60 min and equal to or longer than 60 min. (3) Results: Patients with longer DHCA times were significantly younger (p = 0.001). Intraoperatively, complex procedures with aortic arch surgery were more common in patients with longer DHCA times (p < 0.001). Accordingly, cardiopulmonary bypass (p < 0.001), cross-clamping (p < 0.001) and DHCA times (p < 0.001) were significantly longer in this group. Postoperatively, only the duration of mechanical ventilation (p < 0.001) and the rate of tracheotomy were significantly higher in these patients. Thirty-day mortality was satisfactory for both groups (p = 0.746). (4) Conclusions: Our results showed that improvements in perioperative management including ACP allow for the successful performance of surgical treatment of AAAD under DHCA with a duration of even longer than 60 min.

It Is Advisable to Control the Duration of Hypothermia Circulatory Arrest During Aortic Dissection Surgery: Single-Center Experience

Objective: The duration of hypothermic circulatory arrest (HCA) is one of the important factors affecting the prognosis of arch surgery, which is still controversial. The purpose of this study was to investigate the effect of HCA duration on early prognosis in type A aortic dissection (TAAD) patients who underwent arch surgery in our center. Methods: All consecutive patients who underwent surgical treatment for TAAD in Fuwai Hospital from January 2013 to December 2018 were included in this study and divided into four quartile groups based on HCA time. Baseline characteristics, perioperative indicators, and early mortality were statistically analyzed by propensity score matching (PSM) and restricted cubic spline (RCS) method. Perioperative adverse events were confirmed according to the American STS database and Penn classification. Results: About 1,018 consecutive patients (mean age 49.11 ± 1.4 years, male 74.7%) with TAAD treated surgically were eventually included in this study. After PSM, with the prolongation of HCA time, the surgical mortality rates of group [2,15], (15,18], (18,22], and (22,73] were 4.1, 6.6, 7.8, and 10.9% with p = 0.041, respectively. As shown in RCS, the mortality rate increased sharply after the HCA time exceeded 22 min. And from the subgroup analysis, the HCA time of 22 min or less was associated with better clinical outcomes (OR 2.09, 95%CI 1.25-3.45, p = 0.004). Conclusions: The early mortality increases significantly with the duration of HCA time when arch surgery was performed. And multiple systems throughout the body can be adversely affected.

Optimal circulatory arrest temperature for aortic hemiarch replacement with antegrade brain perfusion

OBJECTIVE

This study sought to identify the optimal temperature for moderate hypothermic circulatory arrest in patients undergoing elective hemiarch replacement with antegrade brain perfusion.

METHODS

The Society of Thoracic Surgeons adult cardiac surgery database was queried for elective hemiarch replacements using antegrade brain perfusion for aneurysmal disease (2014-2019). Generalized estimating equations and restricted cubic splines were used to determine the risk-adjusted relationships between temperature as a continuous variable and outcomes.

RESULTS

Elective hemiarch replacement with antegrade brain perfusion occurred in 3898 patients at 374 centers with a median nadir temperature of 24.9 °C (first quartile, third quartile = 22.0 °C, 27.5 °C) and median circulatory arrest time of 19 minutes (first quartile, third quartile = 14.0 minutes, 27.0 minutes). After adjustment for comorbidities, circulatory arrest time, and individual surgeon, patients cooled between 25 and 28 °C had an early survival advantage compared with 24 °C, whereas those cooled between 21 and 23 °C had higher risks of mortality compared with 24 °C. A nadir temperature of 27 °C was associated with the lowest risk-adjusted odds of mortality (odds ratio, 0.62; 95% confidence interval, 0.42-0.91). A nadir temperature of 21 °C had the highest risk of mortality (odds ratio, 1.4; 95% confidence interval, 1.13-1.73). Risk of experiencing a major morbidity was elevated in patients cooled between 21 and 23 °C, with the highest risk occurring in patients cooled to 21 °C (odds ratio, 1.12; 95% confidence interval, 1.01-1.24).

CONCLUSIONS

For patients with aneurysmal disease undergoing elective hemiarch with antegrade brain perfusion, circulatory arrest with a nadir temperature of 27 °C confers the greatest early survival benefit and smallest risk of postoperative morbidity.

Determinants of outcomes following surgery for type A acute aortic dissection: the UK National Adult Cardiac Surgical Audit

Aims 

Operability of type A acute aortic dissections (TAAAD) is currently based on non-standardized decision-making process, and it lacks a disease-specific risk evaluation model that can predict mortality. We investigated patient, intraoperative data, surgeon, and centre-related variables for patients who underwent TAAAD in the UK.

Methods and results

We identified 4203 patients undergoing TAAAD surgery in the UK (2009–18), who were enrolled into the UK National Adult Cardiac Surgical Audit dataset. The primary outcome was operative mortality. A multivariable logistic regression analysis was performed with fast backward elimination of variables and the bootstrap-based optimism-correction was adopted to assess model performance. Variation related to hospital or surgeon effects were quantified by a generalized mixed linear model and risk-adjusted funnel plots by displaying the individual standardized mortality ratio against expected deaths. Final variables retained in the model were: age [odds ratio (OR) 1.02, 95% confidence interval (CI) 1.02–1.03; P < 0.001]; malperfusion (OR 1.79, 95% CI 1.51–2.12; P < 0.001); left ventricular ejection fraction (moderate: OR 1.40, 95% CI 1.14–1.71; P = 0.001; poor: OR 2.83, 95% CI 1.90–4.21; P < 0.001); previous cardiac surgery (OR 2.29, 95% CI 1.71–3.07; P < 0.001); preoperative mechanical ventilation (OR 2.76, 95% CI 2.00–3.80; P < 0.001); preoperative resuscitation (OR 3.36, 95% CI 1.14–9.87; P = 0.028); and concomitant coronary artery bypass grafting (OR 2.29, 95% CI 1.86–2.83; P < 0.001). We found a significant inverse relationship between surgeons but not centre annual volume with outcomes.

Conclusions 

Patient characteristics, intraoperative factors, cardiac centre, and high-volume surgeons are strong determinants of outcomes following TAAAD surgery. These findings may help refining clinical decision-making, supporting patient counselling and be used by policy makers for quality assurance and service provision improvement.

Treatment of type A dissection: Searching for the Holy Grail

Current principles of surgical treatment of type A dissections are for the most part based on best evidence practice for the lack of controlled randomized studies providing definitive scientific evidence. Despite its widespread use, axillary cannulation still remains a debated topic as the preferred method of cannulation and perfusion strategy in the treatment of this complex condition.