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

Tailored surgical strategies for mini-access open total arch repair

Objective

Open arch repair is perceived as a challenging, high-risk procedure, with a barrier against the use of a minimally invasive approach. We aimed to present a mini-access total arch replacement performed by stratified approaches and to evaluate perioperative outcomes to contribute to the body of evidence.

Methods

We evaluated 40 consecutive patients (aged 69.5 years; interquartile range, 65.6-76.3 years) undergoing elective total arch replacement using 5- to 8-cm upper mini-sternotomy between 2018 and 2022. Surgical strategies, including arterial inflow site and methods of branching vessel reconstruction, were systematically selected at the individual level. To evaluate comparative outcomes, contemporary cases undergoing total arch replacement via sternotomy with similar eligibility criteria served as a control group, and the inverse-treatment-weighting method was used to adjust for baseline characteristics.

Results

Arch-first anastomosis using trifurcate graft, distal-first anastomosis using 4-branch graft, and island anastomosis were used in 18 (45%), 12 (30.0%), and 10 (25%) patients, respectively. Lower body and cardiac ischemic times were 23.4 minutes (interquartile range, 18.0-29.0 minutes) and 66.7 minutes (interquartile range, 50.1-78.2 minutes). There was no early (30-day or in-hospital) mortality, and 2 patients experienced disabling stroke (5.0%). The contemporary control group comprised 55 patients. After an adjustment, a mini-access group showed lower risks of stroke (odds ratio, 0.88; 95% CI, 0.78-1.00; P = .049) and a composite of major complications (odds ratio, 0.79; 95% CI, 0.68-0.92; P = .003), compared with a sternotomy approach.

Conclusions

Based on present results, mini-access total arch replacement may be performed with reasonable safety and efficiency.

Unsolved issues in acute type A aortic dissection

Surgery for acute type A aortic dissection remains challenging with considerable mortality and morbidity despite the remarkable advances in this field. Particularly, surgical outcomes of acute type A aortic dissection are known to be associated with the hospital volume. The optimal cerebral protective method and extent of surgery have been long-standing controversies in acute type A aortic dissection surgery. Given that data from randomized trial are not available and future trials are also unrealistic, observational data based on large registry or meta-analyses may alternatively provide reliable and reasonable evidence. With regard to neuroprotective methods for arch repair, currently available observational data strongly suggest that there are no overt superiority among unilateral-antegrade cerebral perfusion, bilateral-antegrade cerebral perfusion, and retrograde cerebral perfusion, by which their availabilities are still open in real clinical practices depending on institutional preferences. When deciding the extent of arch repair in acute DeBakey type I aortic dissection, multiple factors should be considered altogether such as aortic anatomic characteristics as well as patient's risk profiles for optimizing early safety and late aortic longevity.

Early and long-term results of hypothermic circulatory arrest in aortic surgery: a 20-year single-centre experience

AIMS

The aim of this study was to document the postoperative outcomes of patients who underwent hypothermic circulatory arrest (HCA), the evolution of HCA management over time and to identify the risks factor for early mortality and postoperative stroke.

METHODS

Four hundred and twenty-four patients who underwent aortic surgery with HCA at our institution between January 1995 and June 2016 were consecutively included.

RESULTS

The main indications were degenerative aneurysm (254; 59.9%) and acute type A aortic dissection (146; 34.4%). Interventions were performed under deep (18.4 ± 0.9°C; n = 350; 82.5%) or moderate (23.9 ± 1.9°C; n = 74; 17.5%) hypothermia. Antegrade cerebral perfusion (ACP) was employed in 86 (20.3%) cases. The use of moderate hypothermia significantly increased from 2011, to become the preferred strategy in 2016. The in-hospital mortality was 12.5% and the postoperative stroke rate was 7.1%. Kaplan--Meier 5-year survival was 65.7%. Nonelective timing [odds ratio (OR) 4.05; P < 0.001], stroke (OR 3.77' P = 0.032), renal failure (OR 2.49; P = 0.023), redo surgery (2.42; P = 0.049) and CPB time (OR 1.05; P = 0.03) were independent risk factors for in-hospital mortality in multivariate analysis. Femoral cannulation was the only independent risk factor for stroke (OR 3.97; P = 0.002). The level of hypothermia and the use of ACP were not associated with either in-hospital mortality or postoperative stroke.

CONCLUSION

HCA might be widely considered to achieve a radical treatment of the aortic disease, provided that hypothermia is maintained below the 24°C safety threshold and ACP is used for HCA exceeding 30 min, to ensure optimal brain, spinal cord and visceral organs protection.

Comparative outcomes of total arch versus hemiarch repair in acute DeBakey type I aortic dissection: the impact of 21 years of experience

OBJECTIVES

With the goal of evaluating the impact of experiences at our centre on comparative outcomes between total arch and hemiarch repairs, we reviewed our 21 years of experience with operations for acute type I aortic dissection.

METHODS

Between 1999 and 2019, a total of 365 patients (177 women; 56.8 ± 12.9 years) with acute type I aortic dissection who had a hemiarch (n = 248) or a total arch replacement (n = 117) were evaluated, and the trends in comparative outcomes were analysed.

RESULTS

Over time, deep hypothermic circulatory arrest and retrograde cerebral perfusion were replaced by moderate hypothermia and antegrade cerebral perfusion with the introduction of dedicated aortic surgeons. Overall, operative deaths decreased from 11.0% in time quartile 1 to 2.2% in time quartile 4 (P = 0.090). After adjustment with the use of inverse probability weighting, the total arch group compared with the hemiarch group was at a similar risk of mortality [odds ratio (OR) 0.80, 95% confidence interval (CI) 0.22-2.43; P = 0.71] but at a greater risk of neurological deficit (OR 3.28, 95% CI 1.23-8.98; P = 0.017) in the earlier half period (1999-2009). In the later period (2009-2019), however, both the risks of mortality (OR 0.32, 95% CI 0.03-1.59; P = 0.23) and of neurological injuries (OR 0.42, 95% CI 0.12-1.18; P = 0.13) were comparable between the 2 groups (P for interaction in terms of neurological deficit = 0.007). The multivariable logistic regression model revealed that dedicated aortic surgeons independently contributed to decreased risk of death (OR 0.30, 95% CI 0.09-0.84; P = 0.036).

CONCLUSIONS

These findings indicate that accumulating institutional experiences, along with resultant improvements in surgical strategies and outcomes, may neutralize the surgical risk gap between total arch and hemiarch repair in acute type I aortic dissection.

Mini-access open arch repair

Background

The use of minimally invasive approaches is scarce in open aortic arch repair because of its perceived high operative risk and technical difficulty.

Methods

This study enrolled 59 consecutive patients (aged 58.2±13.2 years) undergoing elective arch replacement either through upper hemi-sternotomy (n=58) or mini-thoracotomy (n=1) between 2015 and 2020. Of these, 44 underwent hemiarch replacement and 15 underwent total arch replacement. Moderate hypothermic circulatory arrest was used for all patients while antegrade cerebral perfusion was selectively used for total arch repair. For more efficient distal aortic anastomosis in limited spaces, inverted graft anastomosis was utilized whenever possible.

Results

Hemi-sternotomy involved upper sternal separation down to the second, third, and fourth intercostal spaces in 1 (1.7%), 30 (50.8%), and 27 (45.8%) patients, respectively. Concomitant cardiac procedures included root replacement in 19 patients (32.2%) and aortic valve replacement in 21 patients (35.6%). Circulatory arrest, cardiac ischemic, cardiopulmonary bypass, and total procedural times were 8.9±3.4, 91.1±31.1, 114.6±46.2, and 250.3±79.5 min, respectively for total arch repair, and 25.0±12.1, 72.3±16.6, 106.0±16.9, and 249.1±41.7 min, respectively for hemiarch repair. Conversion to full-sternotomy was required in 1 patient (1.7%) due to bleeding. There was one case of mortality (1.7%) attributable to low-cardiac output syndrome following hemiarch repair concomitantly with Bentall procedure. Major complications included requirement for mechanical support in 1 (1.7%), temporary neurologic deficit in 1 (1.7%), newly initiated dialysis in 3 (5.1%), and re-exploration due to bleeding in 2 (3.4%).

Conclusions

Mini-access open arch repair is technically feasible and achieved excellent early outcomes.

"Aorta-clamp" technique for surgical repair of acute type A aortic dissection-5 min circulatory arrest at 30 °C

Background

Deep hypothermic circulatory arrest (HCA), which causes perioperative complications, is the foundation of surgical treatment for acute type A aortic dissection (AAAD). To extensively replace the dissected aorta and avoid the negative impacts of HCA, we developed an "aorta-clamp" technique and examined its efficacy in repairing AAAD.

Methods

From November 2014 to August 2016, we recruited 59 consecutive patients (51.3±10.9 years) with AAAD into this study. We performed total arch replacement combined with an elephant trunk implantation using the "aorta-clamp" technique under a 30 °C HCA with continual bilateral antegrade cerebral perfusion.

Results

The average HCA time was 4.9±1.0 min. Twenty-three patients had increased serum creatinine (sCr) before surgery, suggesting an AAAD-associated acute kidney injury (AKI). The sCr level returned to normal in five patients after operation and in 15 before discharge. Six patients (10.2%) with preoperative AKI required postoperative dialysis, and two of these patients (3.4%) died of multiple organ failure. Two patients (3.4%) required re-exploration due to bleeding. One patient (1.7%) exhibited temporary neurologic deficits. There were no late deaths. Computed tomography (CT) examination confirmed the patency of the anastomotic sites and thrombus obliteration of the residual false lumen.

Conclusions

Using the "aorta-clamp" technique with continual bilateral antegrade cerebral perfusion, total arch replacement combined with an elephant trunk implantation can be performed under five minutes of mild (30 °C) HCA. Our data suggest that this technique for the surgical repair of AAAD is a safe, feasible and effective surgical approach with satisfactory early outcomes.