Minimally Invasive Approach for Replacement of the Ascending Aorta towards the Proximal Aortic Arch.

Objectives: In recent years, minimally invasive approaches have been used with increasing frequency, even for more complex aortic procedures. However, evidence on the practicability and safety of expanding minimally invasive techniques from isolated operations of the ascending aorta towards more complex operations such as the hemiarch replacement is still scarce to date. Methods: A total of 86 patients undergoing elective surgical replacement of the ascending aorta with (n = 40) or without (n = 46) concomitant proximal aortic arch replacement between 2009 and 2023 were analyzed in a retrospective single-center analysis. Groups were compared regarding operation times, intra- and postoperative complications and long-term survival. Results: Operation times and ventilation times were significantly longer in the hemiarch replacement group. Despite this, no statistically significant differences between the two groups were observed for the duration of the ICU and hospital stay and postoperative complication rates. At ten-year follow-up, overall survival was 82.6% after isolated ascending aorta replacement and 86.3% after hemiarch replacement (p = 0.441). Conclusions: Expanding the indication for minimally invasive aortic surgery towards the proximal aortic arch resulted in comparable postoperative complication rates, length of hospital stay and overall long-term survival compared to the well-established minimally invasive isolated supracommissural ascending aorta replacement.

Less invasive replacement of aortic root, ascending aorta and hemiarch via partial upper sternotomy: a propensity-score-matched comparison with full sternotomy.

OBJECTIVES: Less invasive surgery has emerged as an option for aortic pathologies. The current study compared our experience on early postoperative results of patients with aortic surgery between partial upper sternotomy (PUS) and full sternotomy (FS). METHODS: We performed a retrospective analysis of the data of patients undergoing aortic root surgery with concomitant ascending aorta and hemiarch replacement. Exclusion criteria were type A aortic dissection and other concomitant major cardiac surgery. After propensity score matching, we compared the perioperative outcomes of patients undergoing surgery with PUS versus FS. RESULTS: A total of 161 patients operated on between January 2013 and September 2022 met the inclusion criteria (PUS: n = 22, FS: n = 139). Propensity score matching yielded 22 pairs with a balanced distribution of propensity scores and covariates between the compared groups. There was no evidence that PUS affects cardiopulmonary bypass [108 (67-119) vs 113 (87-148) min, P = 0.154; PUS vs FS] and circulatory arrest duration [9 (7-10) vs 9 (8-13) min, P = 0.264; PUS vs FS]. There was a reduced cross-clamp duration in the PUS group [88 (58-96) vs 92 (71-122) min, P = 0.032]. Cumulative sum charts have shown consistently low cross-clamp and circulatory arrest duration for 2 experienced surgeons who performed 20 of the procedures in the PUS group (10 each). Perioperative mortality and morbidity were low, with no in-hospital mortality in the PUS group [0 vs 1(4.5%), P > 0.999] and absence of strokes in both groups. CONCLUSIONS: In summary, our initial experience suggests that less invasive aortic root, ascending aorta and hemiarch replacement via PUS could be performed in our patient cohort as safely as via full sternotomy. Advantages for the patient are reduced surgical trauma, improved cosmetic results and-presumably-less pain.

Personalizing patient risk of a life-altering event: An application of machine learning to hemiarch surgery.

OBJECTIVE: The study objective was to assess a machine learning model's ability to predict the occurrence of life-altering events in hemiarch surgery and determine contributing patient characteristics and intraoperative factors. METHODS: In total, 602 patients who underwent hemiarch replacement at a high-volume aortic center from 2009 to 2022 were included. Patients were randomly divided into training (80%) and testing (20%) sets with various eXtreme gradient boosting candidate models constructed to predict the risk of experiencing life-altering events, including stroke, mortality, or new renal replacement therapy requirement. A total of 64 input parameters from the index hospitalization were identified, including 24 demographic characteristics as well as 8 preoperative and 32 intraoperative variables. A SHapley Additive exPlanation beeswarm plot was generated to identify and interpret the impact of individual features on the predictions of the final model. RESULTS: A life-altering event was noted in 15% (90/602) of patients who underwent hemiarch replacement, including urgent/emergency cases and dissections. The final eXtreme Gradient Boosting model demonstrated a cross-validation accuracy of 88% on the testing set and was well calibrated as evidenced by a low Brier score of 0.12. The best performing model achieved an area under the receiver operating characteristic curve of 0.76 and an area under the precision recall curve of 0.55. The SHapley Additive exPlanation beeswarm plot provided insights into key features that significantly influenced model prediction. CONCLUSIONS: Machine learning demonstrated superior accuracy in predicting hemiarch patients who would experience a life-altering event. This model may help to guide patients and clinicians in stratifying risk on an individual basis, which may in turn influence clinical decision-making.

Cannula Placement for Cerebral Protection Without Circulatory Arrest in Patients Undergoing Hemiarch Aortic Aneurysm Repair.

BACKGROUND: Aortic aneurysms involving the proximal aortic arch, which require hemiarch-type repair, typically require circulatory arrest with antegrade cerebral perfusion. Left carotid antegrade cerebral perfusion (LCP) via distal arch cannulation without circulatory arrest was used in this study's patient population. The goal was to assess the operative efficiency and clinical outcomes of using a distal arch cannulation technique that would not require any hypothermic circulatory arrest (HCA) time compared with more traditional brachiocephalic artery cannulation with right-sided unilateral antegrade cerebral perfusion (RCP) and HCA. METHODS: A single-center retrospective review of patients with replacement of the distal ascending aorta involving the proximal arch was performed. Patients with an intramural hematoma or dissection were excluded. Between January 2015 and December 2019, 68 adult patients had undergone a hemiarch repair because of aneurysmal disease. Analysis of baseline demographics, operative data, and clinical outcomes was performed. RESULTS: Comparing the 68 patients: 21 patients were treated with RCP (via brachiocephalic artery graft with HCA), and 47 patients were treated with LCP (via distal aortic arch cannulation with cross-clamp between the brachiocephalic and left common carotid arteries without HCA). Baseline characteristics and outcomes were evaluated for both groups. The LCP group was younger (LCP median [IQR] age, 60 [53-65] years vs RCP median [IQR] age, 67 [59-71] years]. Sex, race, body mass index, comorbidities, and ejection fraction were similar between the groups. Cardiopulmonary bypass time (LCP, 123 minutes vs RCP, 149 minutes) and unilateral cerebral perfusion time (LCP, 17 minutes vs RCP, 22 minutes) were longer in the RCP group. Bleeding, prolonged ventilatory support, kidney failure, and length of stay were similar. In-hospital mortality was 2% in the LCP group vs 0% in the RCP group. Stroke occurred in 2 patients (4.2%) in the LCP group and in 0% of the RCP group. Mortality at 6 months in the LCP and RCP groups was 3% and 10%, respectively. CONCLUSION: Distal arch cannulation with LCP without HCA is a reasonable and safe alternative strategy for patients requiring hemiarch replacement for aneurysmal disease. This technique may provide additional benefits by avoiding circulatory arrest in these complex cases.

Hemiarch versus extended arch repair for acute type A dissection: Results from a multicenter national registry.

OBJECTIVE: We compared perioperative outcomes of patients with acute type A aortic dissection undergoing hemiarch (HA) versus extended arch (EA) repair with or without descending aortic intervention. METHODS: Nine hundred twenty-nine patients underwent acute type A aortic dissection repair (2002-2021, 9 centers) including open distal repair (HA) with or without additional EA repair. EA with intervention on the descending aorta (EAD) included elephant trunk, antegrade thoracic endovascular aortic replacement, or uncovered dissection stent. EA with no descending intervention (EAND), included unstented suture-only methods. Primary outcomes were in-hospital mortality, permanent neurologic deficit, computed tomography malperfusion resolution, and a composite. Multivariable logistic regression was also performed. RESULTS: Mean age was 66 ± 18 years, 30% (278 out of 929) were women, and HA was performed more frequently (75% [n = 695]) than EA (25% [n = 234]). EAD techniques included: dissection stent (39 out of 234 [17%]), thoracic endovascular aortic replacement (18 out of 234 [7.7%]), and elephant trunk (87 out of 234 [37%]). In-hospital mortality (EA: n = 49 [21%] and HA: n = 129 [19%]; P = .42), and neurological deficit (EA: n = 43 [18%] and HA: n = 121 [17%]; P = .74) were similar. EA was not independently associated with death (EA vs HA odds ratio, 1.09; 95% CI, 0.77-1.54; P = .63) or neurologic deficit (EA vs HA odds ratio, 0.85; 95% CI, 0.47-1.55; P = .59). Composite adverse events differed significantly (EA vs HA odds ratio, 1.47; 95% CI, 1.16-1.87; P = .001). Malperfusion resolved more frequently after EAD (EAD: n = 32 [80%], EAND: n = 18 [56%], HA: n = 71 [50%]; P = .004), although multivariable analysis was not significant (EAD vs HA odds ratio, 2.17; 95% CI, 0.83-5.66; P = .10). CONCLUSIONS: Extended arch interventions pose similar perioperative mortality and neurologic risks as Hemiarch. Descending aortic reinforcement may promote malperfusion restoration. Extended techniques should be approached with caution in acute dissection due to increased risk of adverse events.

Acute type A aortic dissection surgery in retrosternal gastric tube reconstruction patient.

BACKGROUND: Retrosternal gastric tube reconstruction is a common surgical technique for managing esophageal cancer, but it complicates acute type A aortic dissection repair and raises concerns about gastric tube damage. CASE PRESENTATION: A 73-year-old female, who underwent esophagectomy with retrosternal gastric tube reconstruction 6 months ago for esophageal cancer, presented with severe chest pain. Acute type A aortic dissection was confirmed by contrast-enhanced computed tomography, and emergency hemiarch replacement through a median sternotomy was performed, preserving the gastric tube without injury. The patient recovered well and was discharged after 3 weeks, showing no gastrointestinal symptoms or signs of mediastinitis.

Persistent left superior vena cava in right hemiarch replacement under deep hypothermic circulatory arrest: A case report.

BACKGROUND: Persistent left superior vena cava (PLSVC), a relatively rare thoracic vascular malformation, can inconvenience perfusionists and operators when encountered during deep hypothermic circulatory arrest (DHCA). CASE SUMMARY: Herein, we describe the case of a patient with concurrent giant aortic arch aneurysm, aortic stenosis, and PLSVC. To treat these conditions, we performed right hemiarch and aortic valve replacements under DHCA. Notably, we applied "bilateral superior vena cava retrograde cerebral perfusion (RCP)" for cerebral protection, which significantly optimized the surgical procedure and reduced the risk of postoperative complications. The patient was discharged 14 d after surgery with no complications. CONCLUSION: Surgical intervention for PLSVC under DHCA can be performed using the bilateral superior vena cava RCP approach.

Natural history of the distal aorta following elective root replacement in patients with Marfan syndrome.

OBJECTIVE: It is unclear if the addition of a prophylactic arch operation is beneficial at the time of root replacement in patients with Marfan syndrome (MFS). This project aims to understand the fate of the distal aorta following elective root replacement in patients with MFS. METHODS: Between 2000 and 2019, 124 adult patients with MFS were identified as having undergone elective aortic root replacement with a clamped distal aortic anastomosis during their lifetime. Serial axial imaging was analyzed. The primary outcome was a composite of subsequent type B aortic dissection (TBAD), aneurysmal degeneration (>4 cm), and aortic reintervention. Secondary outcomes included subsequent TBAD and mortality. RESULTS: Mean age at root replacement was 33.3 years. Median follow-up was 11.3 years. Thirty-one patients (25%) experienced the primary outcome, with no survival difference (P = .9). The crossclamp and aortic cannulation sites were stable (growth rate, 0.33 mm/year), and 2 patients (1.6%) required reintervention there. Twenty-three patients (19.8%) experienced subsequent TBAD. Patients with TBAD had a higher rate of distal degeneration (P < .001), but no significant change in survival (P = .2). Preoperative hypertension (odds ratio, 3.96; P < .05) and younger age at root replacement (odds ratio, 1.05; P < .05) increased the risk of TBAD, based on regression analysis. CONCLUSIONS: The distal aorta (including the clamp and cannulation site) overall appears stable in patients with MFS following elective root replacement without prophylactic arch operation. Development of TBAD seems to be the primary driver of distal degeneration. Factors associated with TBAD development included hypertension, underscoring the importance of strict blood pressure control in these patients.

Ascending aortic and proximal hemiarch replacement with antegrade cerebral perfusion for a penetrating aortic ulcer.

We report the surgical repair of a penetrating aortic ulcer in the distal ascending aorta close to the brachiocephalic trunk, by supracoronary ascending aortic and hemiarch replacement via a full sternotomy. The procedure is performed under moderate hypothermia with bilateral antegrade cerebral perfusion.

Retrograde Cerebral Perfusion May Decrease Stroke Risk During Elective Aortic Arch Surgery.

OBJECTIVE: Controversy remains regarding the optimal neuroprotection strategy for elective hemiarch replacement (HEMI). This study sought to compare outcomes in patients who underwent HEMI utilizing the 2 most common contemporary methods of cerebral protection. METHODS: The ARCH international aortic database was queried, and 782 patients undergoing elective HEMI with circulatory arrest from 2007 to 2012 were identified. There were 418 patients who underwent HEMI using moderate hypothermia (nasopharyngeal temperature 20.1 to 28.0 °C) and antegrade cerebral perfusion (MHCA/ACP). There were 364 patients who underwent HEMI using deep hypothermia (nasopharyngeal temperature 14.1 to 20 °C) and retrograde cerebral perfusion (DHCA/RCP). Adverse outcomes were compared between the groups using both univariable and multivariable analyses. RESULTS: Patients who underwent MHCA/ACP were older (64 vs 61 years, P = 0.01) and more frequently had peripheral vascular disease than DHCA/RCP patients (28.5% vs 7.1%, P < 0.001). Patients in the DHCA/RCP group had a greater incidence of full aortic root replacement (55.8% vs 26.4%, P < 0.001) and more frequently had a central cannulation strategy (83% vs 55.7%, P < 0.001). Cardiopulmonary bypass (170 vs 157 min, P = 0.002) and aortic cross-clamp (134 vs 92 min, P < 0.001) times were significantly longer in the DHCA/RCP group. On univariable analysis, overall mortality was statistically similar between groups (MHCA/ACP 3.4% vs DHCA/RCP 2.3%, P = 0.47), but permanent neurologic deficits were significantly lower in the DHCA/RCP cohort (MHCA/ACP 3.9% vs DHCA/RCP 1.0%, P = 0.02). Multivariable analysis showed no difference in mortality nor perioperative stroke between perfusion cohorts. CONCLUSIONS: Both MHCA/ACP and DHCA/RCP are excellent neuroprotective strategies that produce low mortality in patients undergoing elective HEMI. DHCA/RCP may demonstrate theoretically improved neurologic outcomes compared with MHCA/ACP, but this topic warrants further study.

Association between Bilateral Selective Antegrade Cerebral Perfusion and Postoperative Ischemic Stroke in Patients with Emergency Surgery for Acute Type A Aortic Dissection-Single Centre Experience.

Acute type A aortic dissection (ATAAD) is a surgical emergency with a mortality of 1-2% per hour. Since its discovery over 200 years ago, surgical techniques for repairing a dissected aorta have evolved, and with the introduction of hypothermic circulatory arrest and cerebral perfusion, complex techniques for replacing the entire aortic arch were possible. However, postoperative neurological complications contribute significantly to mortality in this group of patients. The aim of this study was to determine the association between different bilateral selective antegrade cerebral perfusion (ACP) times and the incidence of postoperative ischemic stroke in patients with emergency surgery for ATAAD. Patients with documented hemorrhagic or ischemic stroke, clinical signs of stroke or neurological dysfunction prior to surgery, that died on the operating table or within 48 h after surgery, from whom the postoperative neurological status could not be assessed, and with incomplete medical records were excluded from this study. The diagnosis of postoperative stroke was made using head computed tomography imaging (CT) when clinical suspicion was raised by a neurologist in the immediate postoperative period. For selective bilateral antegrade cerebral perfusion, we used two balloon-tipped cannulas inserted under direct vision into the innominate artery and the left common carotid artery. Each cannula is connected to a separate pump with an independent pressure line. Near-infrared spectroscopy was used in all cases for cerebral oxygenation monitoring. The circulatory arrest was initiated after reaching a target core temperature of 25-28 °C. In total, 129 patients were included in this study. The incidence of postoperative ischemic stroke documented on a head CT was 24.8% (31 patients), and postoperative death was 20.9% (27 patients). The most common surgical technique performed was supravalvular ascending aorta and Hemiarch replacement with a Dacron graft in 69.8% (90 patients). The mean cardiopulmonary bypass time was 210 +/- 56.874 min, the mean aortic cross-clamp time was 114.775 +/- 34.602 min, and the mean cerebral perfusion time was 37.837 +/- 18.243 min. Using logistic regression, selective ACP of more than 40 min was independently associated with postoperative ischemic stroke (OR = 3.589; 95%CI = 1.418-9.085; p = 0.007). Considering the high incidence of postoperative stroke in our study population, we concluded that bilateral selective ACP should be used with caution, especially in patients with severely calcified ascending aorta and/or aortic arch and supra-aortic vessels. All efforts should be made to minimize the duration of circulatory arrest when using bilateral selective ACP with a target of less than 30 min, in hypothermia, at a body temperature of 25-28 °C.

Aortic Arch-Clamping Technique in Hemiarch Replacement Without Circulatory Arrest.

The open anastomosis technique has become more popular since it was first used in hemiarch replacement; however, hypothermic circulatory arrest is unavoidable. This institution performed a novel surgical technique called the arch-clamping technique. It has been used in the treatment of patients with ascending aortic aneurysm extending to the proximal aortic arch and avoids the use of hypothermic circulatory arrest. Thirty patients had a hemiarch replacement with the arch-clamping technique from 2021 to 2022; all of them were discharged uneventfully.

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.

The use of blood and blood products in aortic surgery is associated with adverse outcomes.

OBJECTIVE: To report long-term outcomes after deep hypothermic circulatory arrest (DHCA) with or without perioperative blood or blood products. METHODS: All patients who underwent proximal aortic surgery with DHCA from 2011 to 2018 were propensity matched according to baseline characteristics. Primary outcomes included short- and long-term mortality. Stratified Cox regression analysis was performed for significant associations with survival. RESULTS: A total of 824 patients underwent aortic replacement requiring circulatory arrest. After matching, there were 224 patients in each arm (transfusion and no transfusion). All baseline characteristics were well matched, with a standardized mean difference (SMD) <0.1. Preoperative hematocrit (41.0 vs 40.6; SMD = 0.05) and ejection fraction (57.5% vs 57.0%; SMD = 0.08) were similar between the no transfusion and blood product transfusion cohorts. Rate of aortic dissection (42.9% vs 45.1%; SMD = 0.05), hemiarch replacement (70.1% vs 70.1%; SMD = 0.00), and total arch replacement (21.9% vs 23.2%; SMD = 0.03) were not statistically different. Cardiopulmonary bypass and cross-clamp time were higher in the blood product transfusion cohort (P < .001). Operative mortality (9.4% vs 2.7%; P = .003), stroke (7.6% vs 1.3%; P = .001), reoperation rate, pneumonia, prolonged ventilation, and dialysis requirements were significantly higher in the transfusion cohort (P < .001). In stratified Cox regression, transfusion was an independent predictor of mortality (hazard ratio, 2.62 [confidence interval, 1.47-4.67]; P = .001). One- and 5-year survival were significantly reduced for the transfusion cohort (P < .001). CONCLUSIONS: In patients who underwent aortic surgery with DHCA, perioperative transfusions were associated with poor outcomes despite matching for preoperative baseline characteristics.

Long-term outcomes of hemiarch replacement with hypothermic circulatory arrest and retrograde cerebral perfusion.

OBJECTIVE: This study sought to report outcomes of hemiarch replacement with hypothermic circulatory arrest and retrograde cerebral perfusion, and secondarily, to report outcomes of this operative approach by type of underlying aortic disease. METHODS: This was an observational study of aortic surgeries from 2010 to 2018. All patients who underwent hemiarch replacement with retrograde cerebral perfusion were included, whereas patients undergoing partial or total arch replacement or concomitant elephant trunk procedures were excluded. Patients were dichotomized into 2 groups by underlying aortic disease; that is, acute aortic dissection (AAD) or aneurysmal degeneration of the aorta. These groups were analyzed for differences in short-term postoperative outcomes, including stroke and operative mortality (Society of Thoracic Surgeons definition). Multivariable Cox analysis was performed to identify variables associated with long-term survival after hemiarch replacement. RESULTS: A total of 500 patients undergoing hemiarch replacement with hypothermic circulatory arrest plus retrograde cerebral perfusion were identified, of whom 53.0% had aneurysmal disease and 47.0% had AAD. For the entire cohort, operative mortality was 6.4%, whereas stroke occurred in 4.6% of patients. Comparing AAD with aneurysm, operative mortality and stroke rates were similar across each group. Five-year survival was 84.4% ± 0.02% for the entire hemiarch cohort, whereas 5-year survival was 88.0% ± 0.02% for the aneurysm subgroup and was 80.5% ± 0.03% for the AAD subgroup. On multivariable analysis, AAD was not associated with an increased hazard of death, compared with aneurysm (P = .790). CONCLUSIONS: Morbidity and mortality after hemiarch replacement with hypothermic circulatory arrest plus retrograde cerebral perfusion are acceptably low, and this operative approach may be as advantageous for AAD as it is for aneurysm.

Theoretical Feasibility of Using Arch Branched Endograft Devices for Repair of Post Type A Aortic Dissection in Patients With Prior Ascending Aortic Replacement.

PURPOSE: Ascending aortic replacement is a common emergency procedure for treating acute type A aortic dissection. Secondary open or endovascular interventions for residual arch pathologies is difficult because of adhesions, short prosthetic grafts, and distorted anatomies. Aortic arch branched stent grafts have emerged as a potential solution for these patients if they have suitable anatomical conditions. This study aimed to evaluate the theoretical anatomical and technical feasibility of 2 currently used aortic arch branch endografts in patients who had prior replacement of the ascending aorta. MATERIALS AND METHODS: All patients who had a prosthetic ascending aortic or hemiarch replacement for acute type A dissection in a single institution between January 2013 and December 2018 were included. Contrast computed tomography images on the most recent follow-up were analyzed on a 3-dimensional workstation. Morphological parameters were measured individually for the ascending aorta, aortic arch, supra-aortic branches, and access iliac arteries. The computed tomography scan of each patient was individually evaluated for anatomical suitability for the arch branched and double-branch devices according to set selection criteria. RESULTS: Computed tomography images of 56 patients (median age of 57 years, 45 males) were reviewed. Based on our evaluation, 26 patients (46.4%) were good candidates for an endovascular arch branched device. It would be feasible for 13 patients (23.2%), but prudent preoperative planning was required due to complicated anatomy. The other 17 patients (30.4%) were unsuitable because they met at least 1 exclusion criterion. Short prosthetic grafts, extreme graft angulations, and extensive dissections in the supra-aortic branches were the main reasons for exclusion. CONCLUSION: Endovascular repair using arch branched endografts is feasible in patients with prior ascending aortic arch or hemiarch replacement for acute type A aortic dissection. The most common anatomical conditions that may influence the feasibility of the arch branched endograft procedure include insufficient proximal seal length, severe angulation of the graft, and extensive aortic dissection within the supra-aortic vessels.

Thoraflex Hybrid vs. AMDS: To replace the arch or to stent it in type A aortic dissection?

BACKGROUND: Acute type A aortic dissection (ATAAD) is a life-threatening medical emergency that requires urgent surgical intervention. The mainstay surgical approach to treating ATAAD with aortic arch involvement is total arch replacement (TAR). The frozen elephant trunk (FET) procedure involves TAR with hybrid endovascular stenting of the DTA in a single step using a hybrid prosthesis (HP). The prime example of a FET HP is Thoraflex Hybrid Prosthesis (THP). Another treatment option is the novel Ascyrus Medical Dissection Stent (AMDS) that is deployed as a non-covered stent along with the aortic arch as an adjunct to prior hemi-arch replacement. AIMS: This comparative review highlights the clinical applications and outcomes of THP and AMDS in the treatment of ATAAD and discusses the main differences between both approaches. METHODS: A comprehensive literature search was conducted using multiple electronic databases including PubMed, Google Scholar, Ovid, Scopus and Embase. RESULTS: TAR with FET can be considered the superior approach to managing ATAAD with arch involvement relative to AMDS with hemi-arch replacement due to more optimal clinical outcomes. Upon comprehensively searching the literature, early mortality was substantially lower with FET ranging from 0-11% compared to 12.5-18.7% using AMDS, with more favourable long-term survival. The incidence of kidney injury and new stroke post-FET ranged from 3-20% and 5-16%, and 11-37.5% and 0-18.8% following AMDS implantation. However, evidence supporting the use of AMDS is extremely limited. Meanwhile, TAR with FET is a well-established and well-described procedure for ATAAD repair. CONCLUSION: Despite the novel nature of AMDS, its clinical safety and effectiveness are yet to be proven. In conclusion, THP remains the best evidenced-based approach to treat ATAAD in this era.

Challenging Paradigm Limits of Retrograde Cerebral Perfusion During Lower Body Circulatory Arrest.

INTRODUCTION: Retrograde cerebral perfusion (RCP) is a safe and effective technique to augment cerebral protection during lower body circulatory arrest in patients undergoing elective hemiarch replacement. However, recommendations guiding optimal temperature, flow rate, and perfusion pressure are outdated and potentially overly limiting. We report our experience using RCP for elective hemiarch replacement with parameters that challenge the currently accepted paradigm. METHODS: This was a single-center, retrospective analysis of 319 adult patients who underwent elective hemiarch replacement between February 2010 and 2021 using hypothermic lower body circulatory arrest with RCP alone, RCP followed by antegrade cerebral perfusion (ACP), or ACP alone. Flow rates were adjusted to maintain cerebral perfusion pressure between 30 and 50 mm Hg for RCP and between 40 and 60 mm Hg for ACP. RESULTS: RCP was used in 22.6% (n = 72) of cases, whereas ACP alone was performed in 77.4% (n = 247) of cases. Baseline patient characteristics were similar between groups. Patients undergoing RCP demonstrated shorter cross-clamp time (97.0 min versus 100.0 min, P = 0.034) and shorter lower body circulatory arrest time (7.0 min versus 10.0 min, P < 0.0001) compared with ACP alone. Nadir bladder temperature was equivalent between groups (27.3°C versus 27.5°C, P = 0.752). There were no significant differences in postoperative complications, neurologic outcomes, or mortality. CONCLUSIONS: Moderate hypothermic lower body circulatory arrest combined with RCP at target perfusion pressures of 30-50 mm Hg in patients undergoing elective hemiarch replacement results in equivalent neurologic outcomes and overall morbidity to cases using ACP alone. These results challenge the currently accepted paradigm for RCP, which typically uses deep hypothermia while keeping perfusion pressures below 25 mm Hg.

The impact of prior cardiac surgery on patients undergoing surgical repair for acute type A aortic dissection.

OBJECTIVE: To determine the impact of reoperative versus first-time sternotomy for emergent open repair of acute Type A aortic dissection (ATAAD). METHODS: This was an observational study of consecutive aortic surgeries from 2007 to 2021. Kaplan-Meier survival estimation and multivariable Cox regression analysis were performed to assess the impact of reoperative versus first-time sternotomy upon survival after ATAAD repair. RESULTS: A total of 601 patients with ATAAD were identified, of which 72 (12%) underwent reoperative sternotomy. The reoperative group had a higher prevalence of baseline comorbidities, including hypertension, diabetes, peripheral vascular disease, atrial fibrillation, and coronary artery disease. Central cannulation of the aorta was achieved at a similar rate across each group (81.9% vs. 81.5%, p = .923), and cardiopulmonary bypass (CPB) time was similar across each group (204 ± 84.8 vs. 203 ± 72.4 min, p = .923). Postoperative outcomes were similar across both groups, including in-hospital mortality, stroke, pulmonary complications, renal failure, and reexploration for excessive bleeding. Five-year survival was 74.5% (70.5, 78.3) for the first-time group and was 71.6% (60.0, 81.9) for the reoperative group. After multivariable Cox regression, reoperative sternotomy was not significantly associated with an increased hazard of death compared to first-time sternotomy (hazards ratio: 0.90, 95% confidence interval: 0.56, 1.43, p = .642). CONCLUSIONS: These findings suggest that re-sternotomy can be safely performed with similar outcomes as first-time sternotomy. Central initiation of CPB after sternal reentry limits CPB time and may therefore represent a protective strategy that enhances outcomes for patients presenting with ATAAD and prior cardiac surgery.

Outcomes of hemi- vs. total arch replacement in acute type A aortic dissection: A systematic review and meta-analysis.

Background: Acute type A aortic dissections (ATAAD) pose a challenge to surgeons due to high mortality, and decision making regarding the appropriate procedure is controversial. This study compared the outcomes of hemiarch and total arch replacement for ATAAD. Methods: The PubMed, Web of Science, Embase and Cochrane databases were searched for comparative studies on hemiarch versus total arch replacement that were published before May 1, 2022. Results: We included 23 observational studies with a total of 4,576 patients. Combined data analysis showed that early mortality (RR = 0.82; 95% CI: 0.70-0.97; P = 0.02), incidence of postoperative permanent neurological dysfunction (RR = 0.72; 95%CI:0.54∼0.94; P = 0.02), and incidence of renal failure and dialysis (RR = 0.82; 95%CI:0.71∼0.96; P = 0.01) were all lower for hemiarch than for total arch replacement. However, hemiarch replacement had a higher rate of late mortality (RR = 1.37; 95%CI:1.10∼1.71; P = 0.005). There were no statistically significant differences between the two groups in terms of re-operation for bleeding, aortic re-operation, or postoperative pneumonia. Conclusion: In this study, hemiarch replacement had better early outcomes but a higher late mortality rate than total arch replacement. Decisions regarding the extent of arch repair should be made according to location and extent of ATAAD and the experience of surgeons to ensure the most favorable prognosis. Systematic review registration: [INPLASY.COM], identifier [INPLASY202250088].