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

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

OBJECTIVE

To 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.

METHODS

This 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.

RESULTS

A 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.

CONCLUSIONS

Among 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.

Endovascular repair combined with in situ fenestration for new-onset or residual arch dissection in patients underwent aortic replacement

INTRODUCTION

Ascending aorta or hemi-arch replacement is a frequently used treatment for patients with acute type A thoracic aortic dissection, particularly those who are elderly or have multiple comorbidities. However, in cases where there are secondary entry tears in the aortic arch or descending aorta, this procedure may not fully resolve the issue. The true lumen may remain compressed due to perfusion of the false lumen and usually require reoperation.

METHODS

Between January 2019 and July 2022, 18 patients underwent endovascular total aortic arch repair and fenestration technique without requiring median re-sternotomy. Aortic stent grafts were implanted via the femoral approach, utilizing prosthetic vessels as an appropriate proximal landing zone for aortic stent graft deployment. Based on the debranching conditions of the arch in previous surgery, single, double or triple in situ fenestrations (ISFs) were performed, respectively.

RESULTS

All 18 cases were technically successful, with a median follow-up period of 20 months (range: 18-31 months). All patients had a favourable postoperative course, with no deaths within 30 days or during their hospital stay. There were no instances of disabling stroke, paraplegia, endo-leak, stent graft migration or stent graft-induced new entry. In addition, all patients exhibited complete thrombosis of the false lumen at the level of the aortic arch.

CONCLUSION

Our preliminary experience suggests that endovascular total arch repair combined with ISF technique is a viable, effective and safe option for treatment. Our mid-term results have been promising, but we acknowledge the need for further evaluation to assess long-term outcomes and durability.

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

BACKGROUND

 This meta-analysis compared the outcomes of bilateral cerebral perfusion (BCP) and unilateral cerebral perfusion (UCP) in aortic surgery for acute type A aortic dissection.

METHODS

 A systematic literature search identified 12 studies involving 4,547 patients. Pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated to analyze perioperative characteristics, short-term mortality rates, and postoperative neurological complications.

RESULTS

 No significant differences were found between the BCP and UCP groups in terms of cardiopulmonary bypass time, aortic cross clamp time, lowest body temperature, and lower body circulatory arrest time. Short-term mortality rates (OR [95% CI] = 0.87 [0.64-1.19], p = 0.40) and permanent neurological deficits (OR [95% CI] = 1.01 [0.69-1.47], p = 0.96) were comparable between the groups. However, subgroup analysis of studies exclusively involving total arch replacement showed a lower short-term mortality rate (OR [95% CI] = 0.42 [0.28-0.63], p < 0.01) and permanent neurological deficits (OR [95% CI] = 0.53 [0.30-0.92], p = 0.03) in the BCP group. The BCP group also had a lower rate of temporary neurological deficits (OR [95% CI] = 0.70 [0.53-0.93], p = 0.01), particularly in studies exclusively involving total arch replacement (OR [95% CI] = 0.58 [0.40-0.85], p < 0.01).

CONCLUSION

 This meta-analysis suggests that BCP and UCP yield comparable outcomes. However, BCP may be associated with lower short-term mortality rates and reduced incidence of neurological complications, particularly in cases requiring total arch replacement. BCP should be considered as a preferred cerebral perfusion in specific patient populations.

Hypothermic Circulatory Arrest in Adult Aortic Arch Surgery: A Review of Hypothermic Circulatory Arrest and its Anesthetic Implications

Diseases affecting the aortic arch often require surgical intervention. Hypothermic circulatory arrest (HCA) enables a safe approach during open aortic arch surgeries. Additionally, HCA provides neuroprotection by reducing cerebral metabolism and oxygen requirements. However, HCA comes with significant risks (eg, neurologic dysfunction, stroke, and coagulopathy), and the cardiac anesthesiologist must completely understand the surgical techniques, possible complications, and management strategies.

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.

The impact of circulatory arrest with selective antegrade cerebral perfusion on brain functional connectivity and postoperative cognitive function

Aortic surgery is one of the most challenging types of surgeries, which is possibly related to cognitive sequelae. We aimed to investigate the changes in resting-state functional connectivity (rsFC) associated with intraoperative circulatory arrest (CA) in aortic surgery, exploring the relationship between the altered connectivity and postoperative cognitive functions. Thirty-eight patients participated in this study (14 with CA, 24 without). Functional magnetic resonance imaging was scanned on the fifth day after surgery or after the resolution of delirium if it was developed. We assessed the differences in the development of postoperative cognitive changes and rsFC between patients with and without CA. The occurrence of postoperative delirium and postoperative cognitive dysfunction was not significantly different between the patients with and without the application of CA. However, patients with CA showed increased in posterior cingulate cortex-based connectivity with the right superior temporal gyrus, right precuneus, and right hippocampus, and medial prefrontal cortex-based connectivity with the dorsolateral prefrontal cortex. The application of moderate hypothermic CA with unilateral antegrade cerebral perfusion is unlikely to affect aspects of postoperative cognitive changes, whereas it may lead to increased rsFC of the default mode network at a subclinical level following acute brain insults.

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.

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

OBJECTIVES

The aim of the study is to compare the safety and efficacy of unilateral anterograde cerebral perfusion (UACP) and bilateral anterograde cerebral perfusion (BACP) for acute type A aortic dissection (ATAAD).

METHODS

A systematic review of the MEDLINE (PubMed), Scopus, and Cochrane Library databases (last search: August 7th, 2021) was performed according to the PRISMA statement. Studies directly comparing UACP versus BACP for ATAAD were included. Random-effects meta-analyses were performed.

RESULTS

Eight retrospective cohort studies were identified, incorporating 2416 patients (UACP: 843, BACP: 1573). No statistically significant difference was observed regarding in-hospital mortality (odds ratio [OR]:1.05 [95% Confidence Interval (95% CI):0.70-1.57]), permanent neurological deficit (PND) (OR: 0.94 [95% CI: 0.52-1.70]), transient neurological deficit (TND) (OR: 1.37 [95% CI: 0.98-1.92]), renal failure (OR: 0.96 [95% CI: 0.70-1.32]), and re-exploration for bleeding (OR: 0.77 [95% CI: 0.48-1.22]). Meta-regression analysis revealed that PND and TND were not influenced by differences in rates of total arch repair, Bentall procedure, and concomitant CABG in UACP and BACP groups. Cardiopulmonary bypass time (Standard Mean Difference [SMD]: -0.11 [95% CI: -0.22, 0.44]), Cross clamp time (SMD: -0.04 [95% CI: -0.38, 0.29]), and hypothermic circulatory arrest time (SMD: -0.12 [95% CI: -0.55, 0.30]) were comparable between UACP and BACP. Intensive care unit stay was shorter in BACP arm (SMD:0.16 [95% CI: 0.01, 0.31]); however, length of hospital stay was shorter in UACP arm (SMD: -0.25 [95% CI: -0.45, -0.06]).

CONCLUSIONS

UACP and BACP had similar results in terms of in-hospital mortality, PND, TND, renal failure, and re-exploration for bleeding rate in patients with ATAAD. ICU stay was shorter in the BACP arm while LOS was shorter in the UACP arm.

Application of the aortic balloon occlusion technique in Sun's procedure: A single-center study

OBJECTIVES

To study the impact of a balloon occlusion (BO) technique in stented elephant trunk implantation in Sun's procedure for acute Stanford type A aortic dissection (AAAD) on important postoperative organ complications and patient rehabilitation.

METHODS

Eighty-five patients with AAAD who underwent Sun's procedure from January 2019 to January 2020 were selected. Cases were divided into two groups based on whether the aortic BO technique was used in stented elephant trunk implantation: the BO group and the nonballoon occlusion (NBO) group. The collected data included the patients' clinical characteristics, operative data, postoperative complications and recovery. We applied statistical software to study the impact of a BO technique in stented elephant trunk implantation in Sun's procedure.

RESULTS

A total of 85 patients with AAAD underwent Sun's procedure. A total of 29 used BO technique, 56 did not use. The circulatory arrest time in the BO group was controlled within 8.07 ± 2.33 min, and the nasopharyngeal temperature dropped to 28°C. Overall postoperative complications were less frequent in BO group than NBO group (52% vs. 75%; p = .030). Using BO technique, we reduced the 24-h drainage volume, and lowered the occurrence of hypoxemia (48%), liver dysfunction (10%), and median tracheal intubation time was 37 h (range: 12.5-106 h), median intensive care unit (ICU) time was 65 h (range: 17-207 h).

CONCLUSIONS

During total aortic arch replacement and stented elephant trunk surgery for AAAD, we used the aortic BO technique, which avoids deeper hypothermia and effectively shortens circulatory arrest times. This approach is helpful for reducing the incidence of postoperative complications and shortening the intensive care unit time. This method also reduces the patient's medical burden and facilitates faster recovery.

The New York experience of open arch surgery

BACKGROUND

Aortic arch repair has undergone constant evolution since its inception with improving outcomes. A sizeable number of competing techniques and strategies have been described, with no single optimal method endorsed by the surgical community. We describe our experience with open aortic arch repair in a high-volume center.

METHODS

We queried our aortic database for consecutive patients undergoing aortic arch repair from 1997-2021. Those undergoing hemiarch repair were compared to those undergoing total arch repair. Outcomes were compared using multivariate analysis.

RESULTS

Of 1308 patients undergoing aortic arch repair, 953 underwent hemiarch repair and 355 underwent total arch repair. The median age was 69 [interquartile ratio 58-76] and 61.7% were men. Hemiarch patients more frequently hade aortic dissection (28.5 vs 11.8%, P < 0.001) and urgent or emergent procedure status (45.1 vs 30.4%, P < 0.001). Overall operative mortality was 2.7% and significantly higher in the hemiarch group (3.5 vs 0.6%, P=0.007). No difference in the incidence of major adverse events (MAE) including myocardial infarction, cerebrovascular accident, new need for dialysis, re- exploration for bleeding, and tracheostomy was found between the two groups. Multivariate analysis found diabetes, urgent or emergent procedure status, preoperative renal dysfunction, New York Heart Association class III/IV symptoms, and connective tissue disease to be independent predictors of MAE.

CONCLUSIONS

Retrograde cerebral perfusion with deep hypothermic circulatory arrest is safe and effective, with no appreciable difference in neurologic outcomes when comparing hemiarch to total arch strategies. Rates of mortality and MAE compare favorably with strategies utilizing antegrade cerebral perfusion.

Tips and tricks in redo aortic surgery

Redo aortic surgery is challenging, and the operative risk is higher than that in primary aortic surgery. Preoperative imaging is a crucial guide for a safe re-entry. Scrutinized preparing in cannulation and organ protection strategies have affected surgical outcomes. With comprehensive planning and meticulously executed surgery, mortality and morbidity can be acceptable.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-021-01322-x.

OUP accepted manuscript

Consensus regarding optimal cerebral protection strategy in aortic arch surgery is lacking. We therefore performed a systematic review and meta-analysis to assess outcome differences between unilateral antegrade cerebral perfusion (ACP), bilateral ACP, retrograde cerebral perfusion (RCP) and deep hypothermic circulatory arrest (DHCA). A systematic literature search was performed in Embase, Medline, Web of Science, Cochrane and Google Scholar for all papers published till February 2021 reporting on early clinical outcome after aortic arch surgery utilizing either unilateral, bilateral ACP, RCP or DHCA. The primary outcome was operative mortality. Other key secondary endpoints were occurrence of postoperative disabling stroke, paraplegia, renal and respiratory failure. Pooled outcome risks were estimated using random-effects models. A total of 222 studies were included with a total of 43 720 patients. Pooled postoperative mortality in unilateral ACP group was 6.6% [95% confidence interval (CI) 5.3–8.1%], 9.1% (95% CI 7.9–10.4%), 7.8% (95% CI 5.6–10.7%), 9.2% (95% CI 6.7–12.7%) in bilateral ACP, RCP and DHCA groups, respectively. The incidence of postoperative disabling stroke was 4.8% (95% CI 3.8–6.1%) in the unilateral ACP group, 7.3% (95% CI 6.2–8.5%) in bilateral ACP, 6.4% (95% CI 4.4–9.1%) in RCP and 6.3% (95% CI 4.4–9.1%) in DHCA subgroups. The present meta-analysis summarizes the clinical outcomes of different cerebral protection techniques that have been used in clinical practice over the last decades. These outcomes may be used in advanced microsimulation model. These findings need to be placed in the context of the underlying aortic disease, the extent of the aortic disease and other comorbidities.

Prospero registration number: CRD42021246372

METC: MEC-2019-0825

Contemporary Neuroprotection Strategies during Cardiac Surgery: State of the Art Review

Open-heart surgery is the leading cause of neuronal injury in the perioperative state, with some patients complicating with cerebrovascular accidents and delirium. Neurological fallout places an immense burden on the psychological well-being of the person affected, their family, and the healthcare system. Several randomised control trials (RCTs) have attempted to identify therapeutic and interventional strategies that reduce the morbidity and mortality rate in patients that experience perioperative neurological complications. However, there is still no consensus on the best strategy that yields improved patient outcomes, such that standardised neuroprotection protocols do not exist in a significant number of anaesthesia departments. This review aims to discuss contemporary evidence for preventing and managing risk factors for neuronal injury, mechanisms of injury, and neuroprotection interventions that lead to improved patient outcomes. Furthermore, a summary of existing RCTs and large observational studies are examined to determine which strategies are supported by science and which lack definitive evidence. We have established that the overall evidence for pharmacological neuroprotection is weak. Most neuroprotective strategies are based on animal studies, which cannot be fully extrapolated to the human population, and there is still no consensus on the optimal neuroprotective strategies for patients undergoing cardiac surgery. Large multicenter studies using universal standardised neurological fallout definitions are still required to evaluate the beneficial effects of the existing neuroprotective techniques.

En Bloc Arch Reconstruction With the Frozen Elephant Trunk Technique for Acute Type a Aortic Dissection

Objective: The study objective was to evaluate the effect of en bloc arch reconstruction with frozen elephant trunk (FET) technique for acute type A aortic dissection.

Methods: 41 patients with acute Stanford type A dissection underwent en bloc arch reconstruction combined with FET implantation between April 2018 and August 2020. The mean age of the patients was 46 ± 13 years, and 9 patients were female. One patient had Marfan syndrome. Six patients had pericardial tamponade, 9 had pleural effusion, 5 had transient cerebral ischemic attack, and 3 had chronic kidney disease.

Results: The hospital mortality rate was 9.8% (4 patients). 2 (4.9%) patients had stroke, 23 (56.1%) had acute kidney injury, and 5 (12.2%) had renal failure requiring hemodialysis. During follow-up, the rate of complete false lumen thrombosis was 91.6% (33/36) around the FET, 69.4% (25/36) at the diaphragmatic level, and 27.8% (10/36) at the superior mesenteric artery level. The true lumen diameter at the same three levels of the descending aorta increased significantly while the false lumen diameter reduced at the two levels: pulmonary bifurcation and the diaphragm. The 1-, 2-and 3-year actuarial survival rates were 90.2% [95% confidence interval (CI), 81.2–99.2], 84.2% (95% CI, 70.1–98.3) and 70.2% (95% CI, 42.2–98), respectively.

Conclusions: In patients with acute type A dissection, en bloc arch reconstruction with FET technique appeared to be feasible and effective with early clinical follow-up results. Future studies including a large sample size and long-term follow-up are required to evaluate the efficacy.

Neuroprotective strategies in acute aortic dissection: an analysis of the UK National Adult Cardiac Surgical Audit

OBJECTIVES

The risk of brain injury following surgery for type A aortic dissection (TAAD) remains substantial and no consensus has still been reached on which neuroprotective technique should be preferred. We aimed to investigate the association between neuroprotective strategies and clinical outcomes following TAAD repair.

METHODS

Using the UK National Adult Cardiac Surgical Audit, we identified 1929 patients undergoing surgery for TAAD (2011-2018). Deep hypothermic circulatory arrest (DHCA) only, unilateral (uACP), bilateral antegrade cerebral perfusion (bACP) and retrograde cerebral perfusion were used in 830, 117, 760 and 222 patients, respectively. The primary end point was a composite of death and/or cerebrovascular accident (CVA). Generalized linear mixed model was used to adjust the effect of neuroprotective strategies for other confounders.

RESULTS

The use of bACP was associated with longer circulatory arrest (CA) compared to other strategies. There was a trend towards lower incidence of death and/or CVA using uACP only for shorter CA. In particular, primary end point rate was 27.7% overall and 26.5%, 12.5%, 28.0% and 22.9% for CA <30 min and 28.6%, 30.4%, 33.3% and 33.0% for CA ≥30 min with DHCA only, uACP, bACP and retrograde cerebral perfusion, respectively. The use of DHCA only was associated with five-fold [odds ratio (OR) 5.35, 95% confidence interval (CI) 1.36-21.02] and two-fold (OR 1.77, 95% CI 1.01-3.09) increased risk of death and/or CVA compared to uACP and bACP, respectively, but the effect of uACP was significantly associated with CA duration (hazard ratio 0.97, 95% CI 0.94-0.99; P = 0.04).

CONCLUSIONS

In TAAD repair, the use of uACP and bACP was associated with a lower adjusted risk of death and/or CVA when compared to DHCA. uACP can offer some advantage but only for a shorter CA duration.

Retrograde inferior vena caval perfusion for total aortic arch replacement surgery: a randomized pilot study

Objectives

Antegrade cerebral perfusion (ACP) under moderate hypothermic circulatory arrest is used during total aortic arch replacement surgery (TARS) in patients with acute type A aortic dissection, but it is associated with high mortality and morbidity. We hypothesized that combining ACP with retrograde inferior vena caval perfusion (RIVP) improves outcomes.

Methods

This pilot study was prospective, randomized, controlled and assessor-blinded. Patients scheduled for TARS were randomly treated with either ACP or RIVP + ACP. The primary outcome was a composite of mortality and major complications including paraplegia, postoperative renal failure, severe liver dysfunction, and gastrointestinal complications. Secondary outcomes included neurological complications, length of intubation and requirement of blood products.

Results

A total of 76 patients were recruited (n = 38 per group). Primary outcome occurred in 23 patients (61%) in the ACP group and 16 (42%) in the RIVP + ACP group (OR: 0.60, 95% CI: 0.21–1.62; p = 0.31). There was a lower incidence of transient neurological deficits in the RIVP + ACP group (26% vs. 58%, OR: 0.26; 95% CI: 0.10–0.67,p = 0.006;). The RIVP + ACP group underwent shorter intubation (25 vs 47 h, p = 0.022) and required fewer blood products (red cells, 3.8 units vs 6.5 units, p = 0.047; platelet: 2.0 units vs 2.0 units, p = 0.023) compared with the ACP group.

Conclusions

RIVP + ACP may be associated with lower incidence of transient neurological deficits, shorter intubation and less blood transfusion requirement than ACP alone during TARS. Multi-center, randomized trials with larger samples are required to determine whether RIVP + ACP is associated with lower rates of mortality and major complications.

Trial registration: Pilot study of a RCT registered in clinicaltrials.gov (NCT03607786), Registered 30 July, 2018—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03607786.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-021-02002-9.

Antegrade cerebral perfusion: A review of its current application

The technique of antegrade cerebral perfusion has been adopted by many aortic surgery centers as the routine method of brain protection with some variations in its implementation. These variations stem from the issues with regard to the perfusion pressure, flow, temperature, pH management, hematocrit value, cannulation sites, and unilateral versus bilateral application. In this review, the prespecified issues were discussed and some recommendations about the implementation of antegrade cerebral perfusion were given.

Type A aortic dissection: involvement of carotid artery and impact on cerebral malperfusion

Acute type A aortic dissection is a surgical emergency and management of such pathology can be complex with poor outcomes when there is organ malperfusion. Carotid artery involvement is present in 30% of patients diagnosed with acute type A aortic dissection, and given its emergency and complex nature, there is much controversy regarding the approach, extent of treatment, and timing of the intervention. It is clear that the occurrence of cerebral malperfusion adds an extra layer of complexity to the decision-making framework for treatment. Standardization and validation of the optimal management approach is required, and this should ideally be addressed with large-scale studies. Nonetheless, current literature supports the need for rapid recognition and diagnosis of acute type A aortic dissection with cerebral malperfusion, immediate and extensive surgical repair, and the appropriate use of cerebral perfusion techniques. This paper aims to discuss the current evidence regarding the impact of carotid artery involvement in both the management and outcomes of acute type A aortic dissection.

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

BACKGROUND

We designed a prospective randomized clinical study to compare unilateral and bilateral antegrade cerebral perfusion (ACP) under moderate hypethermia in open distal aortic hemiarch replacement in ascending aortic aneurysm.

METHODS

Forty-two patients were prospectively randomized into two groups; unilateral ACP to Group 1 and bilateral ACP to Group 2. Inclusion criteria were pathological aortic aneurysm in the ascending aorta and/or aortic arch, elective operation, normal preoperative carotid Doppler ultrasonography, and nonexistence of preoperative neurological event. Patients were evaluated with preoperative and postoperative biochemical blood analysis, magnetic resonance imaging (MRI), and neurological disorders. The primary endpoints were permanent neurological disorder and death.

RESULTS

There were 21 patients in each group. Mean age was 56.57 ± 10.06 years in Group 1 and 50.95 ± 15.64 years in Group 2 (p = .170). No significant difference was found according to demographic data. ACP times were significantly higher in bilateral ACP (Group 1: 12.62 ± 5.04 min, Group 2: 18.23 ± 9.04 min, p = .018) whereas cross-clamp time and cardiopulmonary bypass times were not (p = .693 and p = .584 sequentially). Transient neurological disorder was found in seven patients in Group 1 and in 4 patients in Group 2 (p = .484). Postoperative MRI revealed new milimetric ischemic zones in three patients in Group 1 but none in Group 2. No permanent neurological disorder or mortality was seen.

CONCLUSION

The present randomized clinical prospective study could not prove the superiority of one of the technique in cerebral protection probably because, our overall ACP time was too short.

Goal-directed cerebral perfusion in aortic arch surgery: scientific leap or hype?

Although significant advancements in cerebral protection strategies in aortic surgery have been achieved in recent years, controversy remains on what constitutes the optimal strategy. Deep hypothermic circulatory arrest alone is a viable approach in many instances, but the need for a prolonged duration of circulatory arrest and increasing case complexity have led to the utilization of adjunctive cerebral perfusion strategies. In this review, we discuss the efficacy of deep hypothermic circulatory arrest and its limitations, the role of retrograde cerebral perfusion and unilateral and bilateral antegrade cerebral perfusion, and the trend towards goal-directed perfusion strategies, all emphasizing the pressing need for randomized clinical trials to better define the optimal strategy.

Modified Distal Aortic Arch Occlusion During Aortic Arch Replacement

BACKGROUND

Circulatory arrest has been identified as an independent risk factor related to postoperative mortality in patients with Stanford type A aortic dissection. This study described a modified technique for distal aortic arch occlusion that markedly shortened the circulatory arrest time. The early results are encouraging.

METHODS

From May 2016 to September 2018, 51 patients with Stanford type A aortic dissection underwent the modified procedure for aortic arch replacement. All operations were performed via transitory circulatory arrest by clamping the distal aorta between the left common carotid artery and the left subclavian artery. The in-hospital and follow-up data of the treated patients were investigated.

RESULTS

Successful repair of the involved vasculature was achieved in all patients. One (1) patient died due to postoperative aspiration and infection, and three patients required continuous renal replacement therapy due to poor preoperative renal function. The remaining patients were successfully discharged. The median average circulatory arrest time was 5.0 (3.0-6.0) minutes. No cases of tracheotomy, delayed closure, secondary thoracotomy, or other complications occurred. During the follow-up period of 2.4-18.6 months, the implanted grafts and stented elephant trunks were all fully open and not kinked.

CONCLUSIONS

A modified distal aortic arch occlusion can considerably shorten the duration of circulatory arrest. Current experience suggests that this approach can serve as a feasible alternative for patients during aortic arch replacement because of its simplicity and satisfactory clinical effects.

Cerebral protection strategies in aortic arch surgery: A network meta-analysis

OBJECTIVE

Cerebral protection for aortic arch surgery has been widely studied, but comparisons of all the available strategies have rarely been performed. We performed direct and indirect comparisons of antegrade cerebral perfusion, retrograde cerebral perfusion, and deep hypothermic circulatory arrest in a network meta-analysis.

METHODS

After a systematic literature search, studies comparing any combination of antegrade cerebral perfusion, retrograde cerebral perfusion, and deep hypothermic circulatory arrest were included, and a frequentist network meta-analysis was performed using the generic inverse variance method. The primary outcomes were postoperative stroke and operative mortality. Secondary outcomes were postoperative transient neurologic deficits, myocardial infarction, respiratory complications, and renal failure.

RESULTS

A total of 68 studies were included with a total of 26,968 patients. Compared with deep hypothermic circulatory arrest, both antegrade cerebral perfusion and retrograde cerebral perfusion were associated with significantly lower postoperative stroke and operative mortality rates: antegrade cerebral perfusion (odds ratio [OR], 0.62; 95% confidence interval [CI], 0.51-0.75; and OR, 0.63, 95% CI, 0.51-0.76, respectively) and retrograde cerebral perfusion (OR, 0.66; 95% CI, 0.54-0.82; and OR, 0.57; 95% CI, 0.45-0.71, respectively). Antegrade cerebral perfusion and retrograde cerebral perfusion were associated with similar incidence of primary outcomes. No difference among the 3 techniques was found in secondary outcomes. At meta-regression, circulatory arrest duration correlated with the neuroprotective effect of antegrade cerebral perfusion and retrograde cerebral perfusion compared with deep hypothermic circulatory arrest. Unilateral or bilateral antegrade cerebral perfusion and arrest temperature did not influence the results.

CONCLUSIONS

Antegrade cerebral perfusion and retrograde cerebral perfusion are associated with better postoperative outcomes compared with deep hypothermic circulatory arrest, and the relative benefit increases with the duration of the circulatory arrest. No differences between antegrade cerebral perfusion and retrograde cerebral perfusion were found for all the explored outcomes.

Anaesthetic management in endovascular total aortic arch repair via needle-based in situ fenestration: a case series of 14 patients

Objective

Endovascular total aortic arch repair (ETAAR) via needle-based in situ fenestration (ISF) is a major challenge for anaesthesiologists because of haemodynamic instability and the risk of cerebral hypoxia. We herein summarise our experience with anaesthetic management of patients who underwent this procedure.

Methods

Fourteen patients who underwent ETAAR via ISF for arch pathologies involving the major supra-arch branches were included. Regional cerebral oxygen saturation was measured to monitor cerebral perfusion. Partial extracorporeal circulation (EC) support from the right common femoral vein to the right axillary artery was introduced to provide cerebral perfusion.

Results

During ISF, vessel rupture occurred in three patients and ventricular fibrillation occurred in one patient. The regional cerebral oxygen saturation significantly decreased during the potential risk period for cerebral ischaemia. Establishment of EC effectively prevented cerebral ischaemia.

Conclusions

During ETAAR, the risks of haemodynamic instability caused by the procedure and vessel rupture during ISF need to be overcome. Partial EC ensured good cerebral protection in our study, and regional cerebral oxygen saturation monitoring may help to reduce the rate of desaturation.

Unilateral is comparable to bilateral antegrade cerebral perfusion in acute type A aortic dissection repair

OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

A functional assessment of the circle of Willis before aortic arch surgery using transcranial Doppler

BACKGROUND

Antegrade selective cerebral perfusion (ASCP) with systemic moderate hypothermia is routinely used as brain protection during aortic arch surgery. Whether ASCP should be delivered unilaterally (u-ASCP) or bilaterally (bi-ASCP) remains controversial.

METHODS

We routinely studied the functional anatomy of the circle of Willis (CoW in all patients scheduled for arch surgery using transcranial color-coded Doppler over a decade. On the basis of these data, we classified observed functional variants as being "safe," "moderately safe," or "unsafe" for u-ASCP.

RESULTS

From January 2005 to June 2015, 1119 patients underwent aortic arch surgery in our institution. Of these, 636 patients had elective surgery performed with ASCP. Preoperative full functional assessment of the CoW was possible in 61% of patients. A functionally complete CoW was found in only 27%. Of all variants, 72% were classified as being safe for u-ASCP, whereas 18% were moderately safe for u-ASCP, and 10% unsafe. Unsafe variants for bi-ASCP were observed in 0.5% of patients.

CONCLUSIONS

The risk of ischemic brain damage due to malperfusion is estimated to be substantially higher during right u-ASCP than during bi-ASCP. Bi-ASCP is therefore highly preferable over u-ASCP if the function of the CoW is unknown. We propose a tailored approach using this full functional assessment preoperatively by applying u-ASCP via the right subclavian artery when considered safely possible, and bi-ASCP when considered a necessity to prevent cerebral malperfusion, and thus thereby try to reduce the embolic stroke risk of ostial instrumentation in bi-ASCP.

Neuro-protection in open arch surgery

Although antegrade cerebral perfusion (ACP) is the predominant method of protecting the brain in patients undergoing total arch replacement, both deep hypothermic circulatory arrest and ACP provide excellent and comparable clinical outcomes with regard to mortality, stroke, and temporary neurological deficit rates.

[Predictors of neurological complications during surgical treatment of the ascending aorta and aortic arch chronic dissection]

AIM

To evaluate the prognostic significance of oxygen supply to the brain in the risk of neurological complications in the early post operative period of surgical treatment of the ascending aorta and aortic arch.

MATERIAL AND METHODS

The level of oxygenation (rSO2) in the right and left hemispheres was measured in 68 patients with ascending aorta and aortic arch chronic dissection. Before and in the nearest period after surgery, the patients underwent a clinical/instrumental neurological study.

RESULTS

The incidence of ischemic stroke in the early post operative period was 5.9%, cognitive impairment was recorded in 22% of patients. Among the parameters of oxygen supply to the brain, the dynamics of rSO2 during circulatory arrest had a significant impact on the post operative neurological status. The risk of cognitive impairment, besides the association with the oxygen status of the brain, increased with the age of patients and comorbid pathology.

CONCLUSION

The decrease in rSO2 by ≥30% during surgical treatment of ascending aorta and aortic arch dissection increases the risk of ischemic stroke and cognitive impairment in the early post operative period.

Neuroprotective Strategies in Repair and Replacement of the Aortic Arch

Aortic arch surgery is a technical challenge, and cerebral protection during distal anastomosis is a continued topic of controversy and discussion. The physiologic effects of hypothermic arrest and adjunctive cerebral perfusion have yet to be fully defined, and the optimal strategies are still undetermined. This review highlights the historical context, physiological rationale, and clinical efficacy of various neuroprotective strategies during arch operations.

An innovative arch-first surgical procedure under moderate hypothermia for acute type A aortic dissection

BACKGROUND

We hypothesized that the arch-first procedure without extra devices under moderate-to-mild systemic hypothermia during acute type A aortic dissection is safe and efficient and will improve patient outcome compared with the standard total arch replacement technique.

METHODS

From December 2014 to February 2017, 89 patients were enrolled in this study, 52 of whom underwent conventional deep hypothermic circulatory arrest (DHCA, 24.2±0.71 °C) using the antegrade cerebral perfusion surgical procedure (Group A) and 37 of whom underwent the "arch-first" technique with moderate (27.4±1.1 °C) systemic hypothermia during antegrade cerebral perfusion (Group B). The clinical data, surgical and postoperative data, complications, and mortality of the two groups were analyzed.

RESULTS

The cardiopulmonary bypass (171.3±40.0 min) and awakening time (7.0 hours) was significantly decreased in Group B. Two patients died 30 d after surgery (5.4%, two of 37) in Group B. The incidence of transient neurologic deficit (2.7%) and distal organ complications (5.4%) was lower in Group B.

CONCLUSIONS

In patients with acute type A aortic dissection involving the arch, the innovative arch-first surgical procedure could provide feasible and safe treatment outcomes, which brings us closer to the goal of performing surgery with moderate-to-mild systemic hypothermia with better cerebral, distal organ, and survival outcomes.

Aortic arch repair under moderate hypothermic circulatory arrest with or without antegrade cerebral perfusion based on the extent of repair

Background

For aortic-arch repair, moderate hypothermic circulatory arrest (HCA) have shown favorable outcomes over conventional deep HCA when coupled with antegrade cerebral perfusion (ACP); however, recent studies have shown that ACP may not be essential when circulatory arrest time is less than 30 minutes. This study aims to evaluate the stratified arch repair strategy of moderate HCA with or without ACP based on the extent of procedure.

Methods

Consecutive 138 patients (63 female; mean age, 60.2±15.7 years) undergoing open arch repair due to acute aortic syndrome (n=69) or chronic aneurysm (n=69) from January 2012 through April 2017 were enrolled in this study. Stratified neuroprotective strategy was employed according to the extent of repair: hemi-arch repair (n=93) was performed under moderated HCA alone and total-arch repair (n=45) under moderate HCA combined with unilateral ACP.

Results

Median total circulatory arrest and total procedural times were 8.0 minutes [interquartile range (IQR), 6.0-10.0] and 233.0 minutes (IQR, 196.0-290.0 minutes), respectively in the hemi-arch group, and 25.0 minutes (IQR, 12.0-33.0 minutes) and 349.0 minutes (IQR, 276.0-406.0 minutes), respectively in the total-arch group. Early mortality occurred in 2 patients (1.4%) who underwent hemi-arch repair for acute aortic dissection. There was no permanent neurological injury, but 2 cases (1.4%) of temporary neurologic deficit in the hemi-arch group. Other complications included re-exploration for bleeding in 6 (4.3%), postoperative extracorporeal life support in 5 (3.6%) and new-dialysis in 6 (4.3%).

Conclusions

Stratified cerebral perfusion strategy using moderate hypothermia for aortic-arch surgery based on the extent of arch repair showed satisfactory safety and reasonable efficiency.

Brain protection in aortic arch aneurysm: antegrade or retrograde?

During open aortic arch repair, there is an interruption of cerebral perfusion and to prevent neurological sequelae, the hypothermic circulatory arrest has been established to provide sufficient brain protection coupled with adjuncts including retrograde and antegrade cerebral perfusion. To date, brain protection during open aortic arch repair is a contested topic as to which provides superior brain protection with little evidence existing to suggest supremacy of one modality over the other. This article reviews current literature reflecting on key and emerging studies in brain protection and their associated outcomes in patients undergoing open aortic arch surgery.

Long-term outcome and quality of life following emergency surgery for acute aortic dissection type A: a comparison between young and elderly adults

Objectives

Innovations in surgical techniques and perioperative management have continuously improved survival rates for acute aortic dissection type A (AADA). The aim of our study was to evaluate long-term outcome and quality of life (QoL) after surgery for AADA in elderly patients compared with younger patients.

Methods

We retrospectively evaluated 242 consecutive patients, who underwent surgery for AADA between January 2004 and April 2014. Patients were divided into two groups: those aged 70 years and older (elderly group; n  = 78, mean age, 76 ± 4 years) and those younger than 70 years (younger group; n  = 164, mean age, 56 ± 10 years). QoL was assessed with the Short Form Health Survey Questionnaire (SF-36) 1 year after surgery.

Results

The questionnaire return rate was 91.0%. There were already significant differences noted between the two groups with regard to preoperative risk factors on admission. The clinical presentation with a cardiac tamponade was higher in the elderly group (62.8% vs 47.6%; P  = 0.03). Intraoperatively, complex procedures were more common in the younger group (21.3% vs 5.2%; P  = 0.001). Accordingly, cardiopulmonary bypass and cross-clamping times were significantly longer in the younger group. The operative mortality was similar in both groups (3.8% vs 1.2%; P  = 0.33). In the elderly population, 30-day mortality was higher (21.8% vs 7.9%; P  = 0.003). One-year (72% vs 85%), 3-year (68% vs 84%) and 5-year (63% vs 79%) survival rates were satisfactory for the elderly group, but significantly lower compared with the younger group ( P  = 0.008). The physical component summary score also was similar between the groups (39.14 ± 11.12 vs 39.12 ± 12.02; P  = 0.99). However, the mental component summary score might be slightly higher in the elderly group but not statistically significant (51.61 ± 10.73 vs 48.63 ± 11.25; P  = 0.12).

Conclusions

Satisfactory long-term outcome and the general perception of well-being encourage surgery in selected elderly patients with AADA.

Intraoperative care for aortic surgery using circulatory arrest

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

Unilateral Antegrade Cerebral Perfusion and Moderate Hypothermia: Assessing Safety With Novel Biomarkers

BACKGROUND

Antegrade cerebral perfusion in aortic surgery is a well-established brain protection method. Open distal anastomosis during aortic surgery has some well-known advantages. Antegrade cerebral perfusion allows repair to some extent of the aortic arch, even in isolated ascending aortic aneurysm. The present study aims to investigate the adequacy of contralateral perfusion with novel oxidative stress parameters during unilateral antegrade cerebral perfusion.

METHOD

The study included 30 consecutive patients undergoing thoracic aortic surgery with unilateral antegrade cerebral perfusion (uACP) under moderate hypothermia (28° C). Blood samples from right and left jugular vein were obtained at four time intervals during surgery (after the anaesthetic induction - Phase 1, at the beginning of cardiopulmonary bypass - Phase 2, 15^th minute of uACP - Phase 3 and after weaning from cardiopulmonary bypass - Phase 4). Novel oxidative stress parameters (advanced oxidation protein products, sialic acid, thiol reagents and ischaemia-modified serum albumin), blood gas analysis, and serum glucose and lactate levels were measured. In addition, intraoperative and early postoperative follow-up parameters were recorded.

RESULTS

Mean unilateral antegrade cerebral perfusion time was observed to be 16.4±5.9min (9 - 46min). No significant differences between right and left hemispheres were observed in novel oxidative parameters or biochemical values. There was only one temporary neurological deficit (3.3%) in the patient group.

CONCLUSIONS

The present study demonstrated that open distal anastomosis for hemiarch repair can be performed safely with unilateral antegrade cerebral perfusion under moderate hypothermia with both clinical outcome and novel biomarkers.

A Clinical Protocol for Goal Directed Cerebral Perfusion during Aortic Arch Surgery

OBJECTIVE

The optimal strategy to deliver antegrade cerebral perfusion for cerebral protection during hypothermic circulatory arrest has not been established. The purpose of this review was to present our current clinical protocol utilizing selective antegrade cerebral perfusion during aortic arch surgery and to compare it to other published experience.

CLINICAL PROTOCOL

Since 2013, our clinical protocol for aortic arch surgery has evolved to using selective antegrade cerebral perfusion via the innominate artery, moderate hypothermia, and ancillary strategies such as goal-directed perfusion (GDP). Other published techniques favored antegrade cerebral perfusion but were limited by smaller cannulae, multiple cannulation sites, and lower cooling temperatures.

CONCLUSION

Our clinical protocol may offer higher flow rates, avoid complications associated with additional cannulae, and provide an easy setup for dual arterial perfusion. Additionally, GDP has enhanced our understanding of metabolic physiology and may facilitate the development of a better cerebral protection strategy.

Aortic Arch Replacement in Patients With Chronic Dissection: Special Considerations

The progressive expansion of residual, chronic DeBakey type I dissection often necessitates repair of the aortic arch and the distal aorta (ie, descending thoracic and thoracoabdominal aorta). The vast majority of patients with chronic aortic dissection facing aortic arch surgery are survivors of emergent proximal aortic repair for acute dissection, and thus, these patients now face a reoperative procedure necessitating a redo median sternotomy. One approach for repairing the chronic type I aortic dissection incorporates total transverse aortic arch replacement with and without an elephant trunk extension; an elephant trunk extension is a useful strategy, because the proximal descending thoracic aorta is commonly ectatic or aneurysmal at the time of aortic arch repair-using an elephant trunk approach facilitates subsequent repair in the distal aorta. Patients with chronic DeBakey type I dissection should participate in an imaging surveillance protocol.