Aortic balloon occlusion technique versus moderate hypothermic circulatory arrest with antegrade cerebral perfusion in total arch replacement and frozen elephant trunk for acute type A aortic dissection

Hybrid Treatment of Complex Diseases of the Aortic Arch and Descending Thoracic Aorta by Frozen Elephant Trunk Technique

The surgical management of acute and chronic complex diseases involving the aortic arch and the descending thoracic aorta remains challenging. Hybrid procedures associating total open arch replacement and stent-grafting of the proximal descending aorta were developed to allow a potential single-stage treatment, promote remodeling of the downstream aorta, and facilitate a potential second-stage thoracic endovascular aortic repair by providing an ideal landing zone. While these approaches initially used various homemade combinations of available conventional prostheses and stent-grafts, the so-called frozen elephant trunk technique emerged with the development of several custom-made hybrid prostheses. The aim of this study was to review the contemporary outcomes of this technique in the management of complex aortic diseases, with a special focus on procedural planning, organ protection and monitoring, refinements in surgical techniques, and long-term follow-up.

A Strategy for Minimizing Circulatory Arrest Duration in Complex Aortic Arch Procedures

Background and Objectives: Aortic arch pathologies represent a surgical challenge. The challenge is partly due to the necessity of complex cerebral, visceral, and myocardial protection measures. Aortic arch surgery generally requires a significant duration of circulatory arrest, which includes deep hypothermia levels with the associated sequelae. This retrospective observational study shows the feasibility of a strategy that reduces circulatory arrest duration and eliminates the need for deep hypothermia during the procedure. Materials and Methods: Between January 2022 and January 2023, 15 patients (n = 15) with type A aortic dissection underwent total arch replacement with a frozen elephant trunk. Cardiopulmonary bypass and organ perfusion were established via arterial lines in the right axillary artery and one of the femoral arteries. In the latter vessels, a y-branched arterial cannula was used (ThruPort^TM₎, allowing for endo-clamping of the stent part of the frozen elephant trunk with a balloon and subsequent perfusion of the lower body. Results: Applying this modified perfusion technique, circulatory arrest time could be reduced to a mean of 8.1 ± 4.2 min, and surgery was performed at a mean lowest body temperature of 28.9 ± 2.3 °C. The mean ICU and hospital stays were 18.3 ± 13.7 days and 23.8 ± 11.7 days, respectively. The rate for 30-day survival was 100%. Conclusions: By applying our modified perfusion technique, the circulatory arrest duration was below ten minutes. As a consequence, deep hypothermia could be avoided, and surgery could be performed at moderate hypothermia. Future studies will have to show whether these changes may be translated into a clinical benefit for our patients.

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.

Early Outcomes of Three Total Arch Replacement Strategies for DeBakey Type I Aortic Dissection

Background: This study employed three surgical techniques: total arch replacement (TAR) with frozen elephant trunk (FET), aortic balloon occlusion technique (ABO) and hybrid aortic arch repair (HAR) on patients with type I aortic dissection in Fuwai Hospital, aiming to compare the early outcomes of these surgical armamentariums.

Methods: From January 2016 to December 2018, an overall 633 patients (431 of TAR+FET, 122 of HAR, and 80 of ABO) with type I aortic dissection were included in the study. Thirty-day mortality, stroke, paraplegia, re-exploration for bleeding, and renal replacement therapy were compared using the matching weight method (MWM).

Results: After MWM process, the baseline characteristics were comparable among three TAR groups. It showed that ABO group had the longest cardiopulmonary bypass (p < 0.001) and aortic cross-clamp time (p < 0.001), while the operation time was longest in the HAR group (p = 0.039). There was no significant difference in 30-day mortality among groups (p = 0.783). Furthermore, the incidence of stroke (p = 0.679), paraplegia (p = 0.104), re-exploration for bleeding (p = 0.313), and CRRT (p = 0.834) demonstrated no significant difference. Of note, no significant differences were found regarding these outcomes even before using MWM.

Conclusions: Based on the early outcomes, the three TAR approaches were equally applicable to type I aortic dissection. We may choose the specific procedure relatively flexibly according to patient status and surgeon's expertise. Importantly, long-term investigations are warranted to determine whether above approaches remain to be of equivalent efficacy and safety.

The Incidence, Risk Factors and In-Hospital Mortality of Acute Kidney Injury in Patients After Surgery for Acute Type A Aortic Dissection: A Single-Center Retrospective Analysis of 335 Patients

Background: Acute kidney injury (AKI) is a common complication of cardiac surgery, which could lead to increased morbidity and mortality. Acute type A aortic dissection (AAAD) is a life-threatening cardiac disease and can be closely related to post-operative AKI. However, data on the incidence of AKI defined by the newest Kidney Disease: Improving Global Outcomes (KDIGO) criteria and in-hospital mortality of a homogeneous population who underwent AAAD are limited. We aimed to investigate the incidence of AKI defined by the KDIGO criteria and the risk factors associated with the outcomes among AAAD-induced AKI patients. Methods: We reviewed 335 patients who underwent surgical treatment for AAAD between March 2009 and June 2016. We screened the patients' AKI status and analyzed probably risk factors of AKI and in-hospital mortality. Independent-sample t-test or Chi-square test was performed to identify differences between AKI and non-AKI groups and survivors with AKI and non-survivors with AKI, respectively. The logistic regression model was applied to identify independent risk factors. Results: AKI occurred in 71.94% of AAAD patients, including 85 stage 1 (35.26%), 77 stage 2 (31.95%), and 79 stage 3 (32.78%) patients. The in-hospital mortality rate was 21.16%. Logistic regression analysis showed that the body mass index, chronic kidney disease, chronic liver disease, cardiopulmonary bypass duration, red blood cell transfusion, and hypoproteinemia were the independent significant risk factors of the occurrence of post-operative AKI. The risk factors associated with in-hospital mortality among AAAD-induced AKI patients included AKI stage (odds ratio (OR), 3.322), deep hypothermic circulatory arrest (OR, 2.586), lactic acidosis (OR, 3.407), and continuous renal replacement therapy (OR, 3.156). Conclusion: For AAAD patients undergoing surgery, AKI was a common complication, and it increased patients' mortality risk. Therefore, identifying the risk factors of AKI and preventing post-operative AKI are important for improving the post-operative outcomes of AAAD patients. Clinical Trial Registration: ChiCTR, ChiCTR1900021290. Registered 12 February 2019, http://www.chictr.org.cn/showproj.aspx?proj=35795.