Is Emergency Total Arch Replacement With a Modified Elephant Trunk Technique Justified for Acute Type A Aortic Dissection?

Surgical Outcomes Stratified by Type of Transportation and Presence of Coronary Reperfusion in Patients with Coronary Malperfusion Caused by Type A Aortic Dissection

PURPOSE

Owing to the time-sensitive nature of myocardial ischemia, challenging clinical scenarios should be considered in patients with type A acute aortic dissection (AAAD) complicated by coronary malperfusion. In clinical settings, the diagnosis and reperfusion strategies for coronary malperfusion often depend on institutional resources. This study evaluated early surgical outcomes in such patients, focusing on transportation type and clinical management.

METHODS

We retrospectively reviewed 70 patients who underwent emergency surgery for AAAD with coronary malperfusion, excluding those with cardiac tamponade on arrival, between 1997 and February 2024. Patients were divided into 2 groups based on transportation: direct transfer and referral.

RESULTS

Overall, in-hospital mortality was 27%, with only 1 of 9 patients surviving with preoperative peripheral extracorporeal membrane oxygenation (ECMO). Mortality and morbidity did not significantly differ between groups. Univariate analysis identified left coronary artery involvement and preoperative hemodynamic instability as significant risk factors. Additionally, preoperative diagnostic-only coronary angiography (CAG) with unsuccessful reperfusion was a potential risk factor (P = 0.06).

CONCLUSIONS

Regardless of transportation type, preoperative peripheral ECMO itself could not be a definitive solution in AAAD patients with coronary malperfusion. Also, patients who underwent preoperative CAG with unsuccessful reperfusion might be fatal, especially with suspected left coronary artery involvement.

Total Arch vs Hemiarch Repair in Acute Type A Aortic Dissection: Systematic Review and Meta-Analysis of Comparative Studies

Background

We aimed to compare the short- and long-term outcomes of total arch replacement (TAR) vs hemiarch replacement (HAR) in the management of acute type A aortic dissection.

Methods

We searched the literature for studies directly comparing TAR to HAR in acute type A aortic dissection. Hazard ratios (HRs) were extracted from digitized Kaplan-Meier curves.

Results

A total of 6526 patients were identified, of which 2060 (32%) had received a TAR. A total of 37% of patients were female, and the mean age (standard deviation) of the cohort was 59.8 ± 11.8 years. TAR patients had a higher prevalence of preoperative malperfusion (34% vs 26%). The TAR group had higher odds of 30-day mortality (4404 patients; odds ratio [OR] 1.79, 95% confidence interval [CI] 1.29-2.49), renal failure requiring dialysis (3475 patients; OR 1.34, 95% CI 1.02-1.76), and a trend toward higher rates of stroke (3292 patients; OR 1.49, 95% CI 0.93-2.39). No significant differences were observed in prevalence of permanent spinal cord injury, visceral ischemia, or reoperation for bleeding. The TAR group had a non-statistically significant increase in long-term mortality (4408 patients; HR 1.25, 95% CI 0.99-1.57), but showed a trend toward improved freedom from long-term aortic reoperation (1359 patients; HR 0.53; 95% CI 0.18-1.59). In a subgroup analysis, the hazard ratio of long-term mortality favoured TAR in only the subgroup of studies in which the difference in malperfusion was > 10% between groups.

Conclusions

TAR could be associated with improved freedom from long-term aortic reoperation but with potentially increased perioperative risks. We recommend a tailored surgical approach.

Incidence Rates of Penn Classes and Class-Specific Mortality in Acute Type A Aortic Dissection Patients: An Epidemiologic Systematic Review and Meta-Analysis

Acute type A aortic dissection (ATAAD) is a life-threatening emergency that is associated with a high morbidity and mortality rate. One of the complications is end-organ ischemia, a known predictor of mortality. The primary aims of this meta-analysis were to summarize the findings of observational studies investigating the utility of the Penn classification system and to analyze the incidence rates and mortality patterns within each class. The electronic databases PubMed, MEDLINE, and Embase were searched through to April 2023. These were filtered by multiple reviewers to give 10 studies that met the inclusion criteria. The extracted data included patient characteristics, and primary outcomes were the incidence rates of different Penn classes, along with the corresponding mortality for each class. Out of 1,512 studies identified during the initial search, 10 studies, including 4,494 patients, met the inclusion criteria. The pooled incidence of Penn A was highest at 0.55 (95% CI 0.52, 0.58), followed by Penn B at 0.21 (95% CI 0.17, 0.25), and finally Penn C at 0.14 (95% CI 0.11, 0.17). Patients with Penn BC were found to be at the highest risk of death, as their early mortality rates were 0.36 (95% CI 0.31, 0.41). Within those populations, the subtype with the highest individual mortality was Penn C at 0.21 (95% CI 0.15, 0.27), followed by Penn B at 0.19 (95% CI 0.15, 0.23) and Penn A at 0.07 (95% CI 0.05, 0.10). Among patients presenting with ATAAD, class A was most frequently observed, followed by classes B, C, and BC. These findings indicate an incremental increase in mortality rates with the progression of Penn classification.

A new insight into superacute care for type A acute aortic dissection in the Tokyo Acute Aortic Super Network

OBJECTIVE

To determine the status of type A acute aortic dissection using the Tokyo Acute Aortic Super Network.

METHODS

Data of 6283 patients with acute aortic dissection between 2015 and 2019 were collected. Data of 3303 patients with type A acute aortic dissection were extracted for analysis.

RESULTS

Overall, 51.0% of patients were nondirect admissions. On arrival, 23.1% of patients were in shock, 10.0% in cardiopulmonary arrest, and 11.8% in deep coma or coma. Overall, 9.8% of patients were assessed as untreatable. Of 2979 treatable patients, 18.3% underwent medical treatment, whereas 80.7% underwent surgery (open [78.8%], endovascular [1.9%], and peripheral [1.1%] repair). The early mortality rate was 20.5%, including untreatable cases. Among treatable patients, in-hospital mortality rates were 8.6% for open repair, 10.7% for endovascular repair, and 25.3% for medical treatment. Advanced age, preoperative comorbidities, classical dissection, and medical treatment were risk factors for in-hospital mortality. Nondirect admission did not cause increased deaths. The mortality rates were high during the superacute phase following symptom onset.

CONCLUSIONS

This study demonstrated current practices in the emergency care of type A acute aortic dissection via the Tokyo Acute Aortic Super Network system, specifically a high rate of untreatable or inoperable cases and favorable outcomes in patients undergoing surgical treatment. High mortality rates were observed during the super acute phase after symptom onset or hospital arrival.

Systematic total arch replacement with thoraflex hybrid graft in acute type A aortic dissection: A single centre experience

Introduction

In the last two decades, a more aggressive approach has been encouraged to treat patients with acute type A aortic dissection (ATAAD), extending the repair to the aortic arch and proximal descending thoracic aorta with the frozen elephant trunk (FET) implantation. Here, we report our single-centre experience with the FET technique for the systematic treatment of emergency type A aortic dissection.

Materials and methods

Between December 2017 and January 2022, 69 consecutive patients were admitted with ATAAD; of those, 66 patients (62.9 ± 10.2 years of age, 81.8% men) underwent emergency hybrid aortic arch and FET repair with the multibranched Thoraflex hybrid graft and were enrolled in the study. Primary endpoints were 30 days- and in-hospital mortality. Secondary endpoints were postoperative morbidity and follow-up survival. To better clarify the impact of age on surgical outcomes, we have divided the study population into two groups: group A for patients <70 years of age (47 patients), and group B for patients ≥70 years (19 patients). Time-to-event analysis has been conducted using the Log-rank test and is displayed with Kaplan-Meier curves. A multiple Cox proportional Hazard model was developed to identify predictors of long-term survival with a stepwise backward/forward selection process.

Results

30-days- and in-hospital mortality were 10.6 and 13.6%, respectively. Stroke occurred in three (4.5%) patients. Two (3.0%) patients experienced spinal cord ischemia. We did not find any statistically significant difference between the two groups in terms of main post-operative outcomes. The multivariable Cox proportional hazard model showed left ventricular ejection fraction (HR: 0.83, 95% CI: 0.79–0.92, p < 0.01), peripheral vascular disease (HR: 15.8, 95% CI: 3.9–62.9, p < 0.01), coronary malperfusion (HR: 0.10, 95% CI: 0.01–0.77, p =0.03), lower limbs malperfusion (HR: 5.1, 95% CI: 1.10–23.4, p = 0.04), and cardiopulmonary bypass time (HR: 1.02, 95% CI: 1–1.04, p = 0.01) as independent predictors of long term mortality.

Conclusions

Frozen elephant trunk repair to treat emergency type A aortic dissection appears to be associated with good early and mid-term clinical outcomes even in the elderly.

Surgical outcomes of acute type A aortic dissection in septuagenarians and octogenarians

BACKGROUND

We studied surgical outcomes of acute type A aortic dissection and compared early and late outcomes between septuagenarians and octogenarians.

METHODS

From 2010 to 2019, we evaluated 254 consecutive patients with acute type A aortic dissection. We performed emergent operations within 48 h of symptom onset for 188 patients, including 59 septuagenarians and 32 octogenarians.

RESULTS

The overall 30-day mortality rate was 8.5% in septuagenarians and 9.4% in octogenarians (p = 1.0). The hospital mortality rate was 10.2% in septuagenarians and 12.5% in octogenarians (p = 0.74). Multivariate analysis identified prolonged ventilation (≥ 72 h) as a significant risk factor for hospital mortality. Being an octogenarian was not significantly associated with hospital mortality. The actuarial survival rate at 5 years was 80.1% in septuagenarians and 58.5% in octogenarians (log-rank p = 0.09). The freedom from aortic event rate at 5 years was 91.0% in septuagenarians and 100% in octogenarians (log-rank p = 0.23).

CONCLUSION

The two groups showed no significant differences in hospital mortality or morbidity. Our tear-oriented strategies might be appropriate for both septuagenarians and octogenarians. Prolonged ventilation (≥ 72 h) was a significant risk predictor for hospital mortality.

Frozen Elephant Trunk Technique in Acute Type A Aortic Dissection: Is It for All?

Acute type A aortic dissection (ATAAD) is an indisputable emergency with very poor outcomes without surgical treatment. Although the aortic arch is often involved in the aortic dissection, its optimal management during surgical therapy remains uncertain. A conservative tear-oriented approach has traditionally been adopted, limiting the procedure to the ascending aorta (or hemiarch) replacement. However, dilation of the residual dissected aorta and subsequent rupture may occur, requiring further intervention in the future. In the last two decades, the frozen elephant trunk (FET) technique has become a valid and attractive option to treat aortic disease when the arch and the thoracic aorta are involved, both in elective and in emergency settings. Here, we report a review of the contemporary literature regarding the short- and long-term outcomes of the FET technique in ATAAD repair.

Comparative study of Japanese frozen elephant trunk device for open aortic arch repairs

OBJECTIVE

We performed a multicenter prospective comparative study to determine the impact of a Japanese frozen elephant trunk device on total arch replacement compared with conventional repair without it.

METHODS

Between 2016 and 2019, a total of 684 patients (frozen elephant trunk procedure; n = 369; conventional repair, n = 315) from 41 institutions were enrolled. The 2 procedures were selected according to each center's strategy.

RESULTS

The frozen elephant trunk procedure was applied more for aortic dissection, whereas the conventional repairs were predominantly performed for aneurysms. In the former, only hypothermic circulatory arrest time was reduced among the intraoperative parameters. Although there were no differences in the 30-day and in-hospital mortality rates (0.8% and 1.6%, respectively, for the frozen elephant trunk procedure vs 0.3% and 0.6%, respectively, for conventional repair), the neurologic complication rates were significantly higher in stroke (5.7% vs 2.2%; P = .022) and paraplegia (1.6% vs 0%; P = .023). In the propensity score matching analyses using 11 variables, statistical significance disappeared in the differences for mortality and neurologic morbidity (stroke and paraplegia/paraparesis) rates of 194 patients of each group, although they were still higher for the frozen elephant trunk procedure.

CONCLUSIONS

The early outcomes of total arch replacement with the frozen elephant trunk procedure were acceptable despite its higher prevalence of emergency or redo surgery, which was comparable to that of the conventional repair. This procedure had higher rates of spinal cord injury than the conventional repair, which is a disadvantage of this approach.

Efficacy of entry exclusion strategy for DeBakey type III retrograde Stanford type A acute aortic dissection

OBJECTIVES

Resection of a primary entry tear is essential for the treatment of Stanford type A acute aortic dissection (AAAD). In DeBakey type III retrograde AAAD (DBIII-RAAAD), resection of the primary entry tear in the descending aorta is sometimes difficult. The frozen elephant trunk technique and thoracic endovascular aortic repair (TEVAR) enable the closure of the primary entry in the descending aorta. The aim of this study was to investigate the efficacy of resection or closure of primary entry, i.e. entry exclusion, in patients with DeBakey type III retrograde-AAAD.

METHODS

The medical records of 654 patients with AAAD who underwent emergency surgery between January 2000 and March 2019 were retrospectively reviewed, and 80 eligible patients with DeBakey type III retrograde-AAAD were divided into the excluded (n = 50; age, 62 ± 12 years) and residual (n = 30; age, 66 ± 14 years) groups according to postoperative computed tomography angiographic data of the false lumen around the primary entry. The excluded group was defined as having a postoperative false lumen at the level of the elephant trunk or thrombosis of the endograft including primary entry. Patients with early false lumen enhancement around the elephant trunk or an unresected primary entry tear after isolated hemiarch replacement were included in the residual group. The early and long-term surgical outcomes were compared between the groups.

RESULTS

The in-hospital mortality rate was 8% (6/80), with no significant difference observed between the excluded and the residual groups (10% and 7%, respectively; P > 0.99). Ninety-five percentage of the patients (20/21) achieved entry exclusion with stent grafts including the frozen elephant trunk procedure and TEVAR. Spinal cord ischaemia was not observed in either group. The cumulative overall survival at 5 years was comparable between the 2 groups (76% and 81% in the excluded and residual groups, respectively; P = 0.93). The 5-year freedom from distal aortic reoperation rate was significantly higher in the excluded group (97%) than in the residual group (97% vs 66%; P = 0.008).

CONCLUSIONS

Not only resection but also closure using the entry exclusion approach for DeBakey type III retrograde-AAAD utilizing new technologies including the frozen elephant trunk technique and TEVAR might mitigate dissection-related reoperations.

Comparative study of the frozen elephant trunk and classical elephant trunk techniques to supplement total arch replacement for acute type A aortic dissection†

OBJECTIVES

In patients with acute type A aortic dissection, the use of the frozen elephant trunk (FET) procedure with total arch replacement (TAR) has been indicated for emergency operations to obtain thrombosis of the distal false lumen (FL). However, data comparing the FET and the classical elephant trunk (CET) procedures, including the incidences of mortality, morbidity, spinal cord injury and aortic remodelling, have not yet been reported. The goal of this study was to compare the early outcomes of TAR with the FET and the CET procedures.

METHODS

The past 7 years of medical records of 323 patients with type A aortic dissection who underwent emergency surgery were reviewed retrospectively, and 148 patients who underwent TAR were shortlisted for the study. First, the patients were divided into 2 groups, the CET group (n = 115; age 65 ± 12 years) and FET group (n = 33; 67 ± 11 years), to compare the early operative outcomes, including mortality and morbidity. Second, 86 patients (CET 56; FET 30) fulfilling the inclusive criteria (inserted length of elephant trunk ≥5 cm, involvement of dissection at the descending aorta and sufficient computed tomographic evaluation at ≥6 months after the operation) were compared to evaluate the patency and diameter of the FL at each segment of the downstream aorta.

RESULTS

The in-hospital mortality rate was 8.1% (12/148), without significant differences between the 2 groups (CET 8.7% vs FET 6.1%; P = 1). No spinal cord ischaemia was encountered in either group. The incidence of postoperative FL patency at the level of the left lower pulmonary vein was 30% in the FET group, which was significantly lower than that in the preoperative state (73%) and in the CET group (77%). The downsizing of the aortic diameter at the distal edge of the CET or the FET, the left lower pulmonary vein and the coeliac axis was significant in the FET group 6 months after TAR.

CONCLUSIONS

According to our initial experience, the FET compared to the CET procedure showed comparable early complications and an advantage concerning FL thrombosis and aortic remodelling at early follow-up examinations.

What is the optimal surgical strategy for Stanford Type A acute aortic dissection in patients with a patent false lumen at the descending aorta?

OBJECTIVES

Aggressive total arch replacement (TAR) to obtain thrombosis of the distal false lumen (FL) in patients with Stanford Type A acute aortic dissection, particularly with a patent FL at the descending aorta, is discussed. The aim of this study was to examine the efficacy of our strategy.

METHODS

In the last 20 years, we retrospectively reviewed the records of 518 patients with Type A acute aortic dissection who underwent an emergent surgery. Among them, 290 patients with a preoperative patent FL at the descending aorta were enrolled in this study. Patients were divided in 2 groups: the non-TAR group (n = 124; 68 ± 14 years) and the TAR group (n = 166; 61 ± 13 years).

RESULTS

In-hospital mortality was 11% (32/290) without significant difference between the 2 groups (the non-TAR group 13% vs the TAR group 10%, P = 0.45). The rates of FL thrombosis of the entire descending aorta were detected at 32% in the non-TAR group and 41% in the TAR group (P = 0.16). Freedom from distal aortic dilatation ≥50 mm was significantly higher in the TAR group (P = 0.03) than in the non-TAR group. Independent predictors of distal aortic dilatation >50 mm were patients in the non-TAR group (P = 0.01; hazard ratio 3.1, 95% confidence interval 1.28-8.05) and unachieved primary entry tear resection (P = 0.002; hazard ratio 6.2, 95% confidence interval 1.38-8.66).

CONCLUSIONS

Our surgical strategy with an aggressive entry resection with higher rate of TAR was acceptable. In patients with a patent FL at the descending aorta, TAR should be considered to prevent the future growth of the distal aorta.

Kinetic Elephant Trunk Technique: Early Results in Chronic Symptomatic Aortic Dissection Management

BACKGROUND

The aim was to expand our understanding of the dynamic evolution of the aorta throughout the dissection time course. We investigated how the disease process can be modulated to equalize lumen pressure, enhance perfusion, and stabilize the aorta along its entire length using the kinetic elephant trunk (kET) technique.

METHODS

We performed the kET on 9 patients with chronic symptomatic aortic dissection (CSAD) as a primary or secondary intervention, regardless of the chronicity of the dissection. Endovascular scissoring of the intraluminal septum is performed in the infradiaphragmatic dissected aorta to equalize pressure between true and false lumens and allow all branched vessels to be supplied from one lumen. The Streamliner Multilayer Flow Modulator (SMFM), an uncovered cobalt-alloy aortic device, is deployed from the aortic sinus, covering the supra-aortic branches, distally into the distal aorta (primary intervention). In the case of a previous ascending aorta Dacron graft, the SMFM is deployed (secondary intervention) at the level of the Dacron graft so that it is overlapped with the graft and landed in the distal aorta.

RESULTS

In the initial study period, all-cause and aortic-related survival were 100%, respectively; all great vessels and visceral branches were patent; and freedom of stroke, end-organ ischemia, paraplegia, and renal failure were 100%.

CONCLUSIONS

The kET is a treatment process for managing CSAD. Its simplicity, consistency, and reproducibility in high-risk patients with low morbidity and mortality add to the armamentarium of the cardiovascular specialist. Further assessment of the medium- and long-term outcomes is needed to fully establish the benefits of kET.

Techniques and outcomes of secondary open repair for chronic dissection after acute repair of type A aortic dissection

Despite successful repair of acute type A aortic dissection (TAAD), the distal false lumen may remain patent resulting in progressive degeneration of the remaining distal aorta. This can lead to aneurysmal dilatation and risk of rupture. Open distal reoperation to replace the residually dissected thoraco-abdominal aorta may be accomplished with acceptable morbidity and mortality in experienced hands. This can be facilitated when the index operation for acute TAAD is tailored to exclude all primary tears and set the arch and descending aorta for a subsequent open, endovascular or hybrid procedure.

Impact of connective tissue disease on the surgical outcomes of aortic dissection in patients with cystic medial necrosis

Background

A retrospective analysis was performed to determine the impact of genetically diagnosed connective tissue disease (CTD) on the early and late outcomes of surgical treatment for aortic dissection in patients having aortic pathology associated with cystic medial necrosis (CMN).

Methods

Between 2003 and 2013, a total of 43 patients (37 ± 12.8 years old, 23 men, 20 women) who had undergone surgery for aortic dissection associated with CMN in the aortic wall underwent genetic examinations. Subsequently, there were 30 patients with CTD (CTD group) and 13 without CTD (non-CTD group).

Results

There were no early or late deaths (the follow-up rate was 100% for 57.1 ± 43.0 months). The median age was significantly lower in the CTD group (p = 0.030). The rate of elastic fiber loss was significantly higher in the CTD group (p = 0.014). In the long-term follow-up, there were no significant differences in the incidences of re-dissection (p = 0.332). However, re-operations were required more frequently in the CTD group (p = 0.037).

Conclusions

In patients with CTD as well as CMN, the onset of aortic dissection tends to be earlier, which would result in higher rates of re-operation, compared with the non-CTD group. Closer and stricter follow-up with medication and adequate surgical treatments with appropriate timing are mandatory for such high-risk patients.

Classification and outcomes of extended arch repair for acute Type A aortic dissection: a systematic review and meta-analysis

Objectives

Distal extent of repair in patients undergoing surgery for acute Type A aortic dissection (ATAAD) is controversial. Emerging hybrid techniques involving open and endovascular surgery have been reported in small numbers by select individual centres. A systematic review and meta-analysis was performed to investigate the outcomes following extended arch repair for ATAAD. A classification system is proposed of the different techniques to facilitate discussion and further investigation.

Methods

Using Ovid MEDLINE, 38 studies were identified reporting outcomes for 2140 patients. Studies were categorized into four groups on the basis of extent of surgical aortic resection and the method of descending thoracic aortic stent graft deployment; during circulatory arrest (frozen stented elephant trunk) or with normothermic perfusion and use of fluoroscopy (warm stent graft): (I) surgical total arch replacement, (II) total arch and frozen stented elephant trunk, (III) hemiarch and frozen stented elephant trunk and (IV) total arch and warm stent graft. Perioperative event rates were obtained for each of the four groups and the entire cohort using pooled summary estimates. Linearized rates of late mortality and reoperation were calculated.

Results

Overall pooled hospital mortality for extended arch techniques was 8.6% (95% CI 7.2-10.0). Pooled data categorized by surgical technique resulted in hospital mortality of 11.9% for total arch, 8.6% total arch and frozen stented elephant trunk, 6.3% hemiarch and frozen stented elephant trunk and 5.5% total arch and 'warm stent graft'. Overall incidence of stroke for the entire cohort was 5.7% (95% CI 3.6-8.2). Rate of spinal cord ischaemia was 2.0% (95% CI 1.2-3.0). Pooled linearized rate of late mortality was 1.66%/pt-yr (95% CI 1.34-2.07) with linearized rate of re-operation of 1.62%/pt-yr (95% CI 1.24-2.05).

Conclusions

Perioperative results of extended arch procedures are encouraging. Further follow-up is required to see if long-term complications are reduced with these emerging techniques. The proposed classification system will facilitate future comparison of short- and long-term results of different techniques of extended arch repair for ATAAD.

Elephant Trunk

Background. Since Borst and colleagues first applied the elephant trunk technique more than 30 years ago, it has become a standard method in approach for staged repair of an extensive thoracic aneurysm. While the original technique was cumbersome, a number of innovations have significantly improved the results over the past 3 decades. Conclusions. Today, total arch replacement with elephant trunk provides simplified staged surgery but, nonetheless, remains a complex surgical procedure. Although many proximal aortic procedures may be addressed with ascending and partial transverse arch replacement, when total or complete transverse arch replacement is required, then the use of the elephant trunk technique, whether standard or frozen, should be considered.

Contemporary insights into the management of type A aortic dissection

INTRODUCTION

Acute Type A Dissection remains a surgical emergency with a relatively high operative mortality despite advances in cardiac surgical techniques and medical management over the past thirty years.

AREAS COVERED

In this presentation we will discuss the issues surrounding diagnosis, triage, surgical treatment and perioperative medical management as well as long term surveillance of patients suffering from Acute Type A Dissection and present the literature that supports our management strategies. Expert commentary: The ultimate goal of surgical intervention for patients with Type A Acute Aortic Dissection is an alive patient. A more complicated operation which addresses the root and arch and potentially reduces late complications should be approached with caution since it may increase the operative mortality of the procedure itself. With the recent evolution in endovascular techniques, there is hope that later complications can be reduced without increasing the risk of the primary operation. It remains to be seen whether the improved distal aortic remodeling afforded by a combined open/endovascular approach to Acute Type A Dissection will lead to decreased need for aortic reinterventions and overall long term complications of a residual descending thoracic chronic dissection.

Descending endografts for type A dissections: con

An important goal of surgical repair of type A aortic dissection is to resect the intimal tear. Studies on the fate of residual dissection after acute type A aortic dissection repair in the past decade have driven surgeons to seek procedures to avoid distal reoperation. Aggressive surgical approach with total arch replacement in acute type A dissection has demonstrated lower incidence of distal reoperation and slower aortic growth rate compared to less aggressive ascending/hemiarch repair. Recently, successful results of thoracic endovascular aortic repair (TEVAR) in type B aortic dissection have encouraged surgeons to further attack acute type A aortic dissection with hybrid approach: antegrade endografting in the descending thoracic true lumen as an adjunct to hemiarch or total arch repair. However, is the hybrid approach with simultaneous descending endografting justified in all the acute type A aortic dissection cases? The outcomes of the hybrid approach reported by the several groups have demonstrated 80-100% of false lumen thrombus formation in the proximal descending aorta (stented segment); however, the complete obliteration of the false lumen is only 17-50%. The incidence of distal reoperation/reintervention after hybrid approach is as high as 14% and an adjunctive procedure is often performed. Moreover, there are concerns about additional risks associated with the hybrid procedures, such as spinal cord injury (SCI), stent graft induced new entry and stroke. The data on this new approach are still very limited. Hence, further study is warranted to prove its safety and durability.

Descending endograft for DeBakey type 1 aortic dissection: pro

The surgical management of patients with DeBakey type 1 acute aortic dissection (DBT1-AAD) represents a major challenge for aortic surgeons. It has been demonstrated that the distal false lumen remains patent in about 70% to 80% of patients undergoing DBT1-AAD surgery and that a patent false lumen worsens the prognosis. In order to improve long term outcomes and reduce the frequency of late aneurysm formation and reoperation, a more aggressive primary operation involving total arch replacement (TAR) and concomitant antegrade stenting of the descending thoracic aorta (DTA) with a frozen elephant trunk (FET) has been introduced. Such extensive operations, however, remain controversial due to their increased technical complexity and perceived higher operative mortality and morbidity. This perspective article will overview the rationale behind, and the potential advantages and current evidence for, FET surgery in acute aortic dissection.

A Meta-Analysis of Total Arch Replacement With Frozen Elephant Trunk in Acute Type A Aortic Dissection

Objectives:

To assess the safety and efficacy, we performed a meta-analysis of total arch replacement with frozen elephant trunk in exclusive acute type A (neither chronic nor type B) aortic dissection.

Methods:

Databases including MEDLINE and EMBASE were searched through March 2015 using Web-based search engines (PubMed and OVID). Eligible studies were case series of frozen elephant trunk enrolling patients with acute type A (neither chronic nor type B) aortic dissection reporting at least early (in-hospital or 30-day) all-cause mortality. Study-specific estimates were combined in both fixed- and random-effect models.

Results:

Fifteen studies enrolling 1279 patients were identified and included. Pooled analyses demonstrated the cardiopulmonary bypass time of 207.1 (95% confidence interval [CI], 186.1-228.1) minutes, aortic cross-clamp time of 123.3 (95% CI, 113.1-133.5) minutes, selective antegrade cerebral perfusion time of 49.3 (95% CI, 37.6-61.0) minutes, hypothermic circulatory arrest time of 39.0 (95% CI, 30.7-47.2) minutes, early mortality of 9.2% (95% CI, 7.7-11.0%), stroke of 4.8% (95% CI, 2.5-9.0%), spinal cord injury of 3.5% (95% CI, 1.9-6.6%), mid- to long-term (≥1-year) overall mortality of 13.0% (95% CI, 10.4-16.0%), reintervention of 9.6% (95% CI, 5.6-15.8%), and false lumen thrombosis of 96.8% (95% CI, 90.7-98.9%).

Conclusions:

Total arch replacement with frozen elephant trunk provides a safe alternative to that with conventional elephant trunk in patients with acute type A aortic dissection, with acceptable early mortality and morbidity. The rates of mid- to long-term reintervention and false lumen non-thrombosis may be lower in patients undergoing the frozen than conventional elephant trunk procedure.

Change of Proximal Descending Aortic False Lumen after Conventional Repair of Acute Type I Dissection: Is It Always Unfavorable?

Background

Some patients show favorable changes in the descending aortic false lumen after conventional repair of acute type A dissection, although the incidence of favorable changes has been reported to be low. We aimed to investigate the incidence of positive postoperative changes in the false lumen and the factors associated with positive outcomes.

Methods

In 63 patients who underwent surgery for type A acute dissection as well as serial computed tomography (CT) scanning, morphological parameters were compared between the preoperative, early postoperative (mean interval, 5.4 days), and late CT scans (mean interval, 31.0 months) at three levels of the descending thoracic aorta.

Results

In the early postoperative CT images, complete false lumen thrombosis and/or true lumen expansion at the proximal descending aorta was observed in 46% of the patients. In the late images, complete thrombosis or resolution of the proximal descending false lumen occurred in 42.9% of the patients. Multivariate analysis found that juxta-anastomotic false lumen thrombosis was predictive of favorable early changes, which were in turn predictive of continuing later improvement.

Conclusion

Even after conventional repair without inserting a frozen elephant trunk, the proximal descending aortic false lumen showed positive remodeling in a substantial number of patients. We believe that the long-term prognosis of type A dissection can be improved by refining surgical technique, and particularly by avoiding large intimal tears at the anastomosis site during the initial repair.

Generalized ischaemia in type A aortic dissections predicts early surgical outcomes only

OBJECTIVES

In patients with acute type A aortic dissection (aTAAD), early post-surgical outcomes are largely influenced by preoperative conditions, specifically localized or generalized ischaemia. Such states are reflected in the recent Penn classification. Our aim was to determine the impact of preoperative ischaemia (by Penn class) on in-hospital and long-term mortality.

METHODS

All consecutive patients (n = 341) surgically treated for aTAAD between 1998 and 2014 were recruited for a retrospective observational study. Parameters impacting in-hospital and long-term mortality were identified through univariable and multivariable analyses.

RESULTS

In-hospital mortality rates by Penn class were as follows: Class Aa, 11%; Class Ab, 14%; Class Ac, 42% and Class Abc, 29%. Both Ac [odds ratio (OR) = 4.4; 95% confidence interval (CI), 1.92-9.80] and Abc (OR = 3.72; 95% CI, 1.26-10.99) classifications independently predicted in-hospital mortality, as did cardiopulmonary bypass time (OR = 1.01; 95% CI, 1.00-1.01). Relative to Class Aa patients, survival did not differ significantly in Class Ac and Abc subsets (log-rank P = 0.365 and P = 0.716, respectively), once 30-day postoperative deaths were excluded. The leading cause of late mortality was cardiac failure or myocardial infarction (29%), followed by aortic rupture (25%). Independent predictors of long-term mortality after aTAAD were age [hazard ratio (HR) = 1.08; 95% CI, 1.05-1.10] and supracoronary replacement graft (HR = 2.27; 95% CI, 1.1-4.75).

CONCLUSIONS

Penn classes Ac and Abc were identified as an independent risk factor for in-hospital mortality, whereas neither Penn class nor organ-specific ischaemia significantly impacted long-term survival. Regardless of ischaemic manifestations at presentation, the prognosis of patients surviving both surgery and early postoperative period proved acceptable.

Results of "elephant trunk" total aortic arch replacement using a multi-branched, collared graft prosthesis

We report on our experience with a simplified elephant trunk (ET) procedure with a multi-branched prosthesis (Vascutek(®) Siena™ Collared Graft). It consists of a proximal portion (20 cm) with prefabricated side branches, a collar and a distal portion (30 cm). The collar, which can be trimmed into any desired diameter, constitutes the suture portion to the descending aorta. Radiopaque markers in the distal portion indicate the landing zone. Between January 2011 and June 2013, 20 consecutive patients (10 women; mean age, 66 ± 9.3 years) underwent ET procedure, including 6 re-do cases. Underlying aortic diseases were acute dissection (n = 6), chronic dissection (n = 4), aneurysm (n = 8) and PAU (n = 2). Mean preoperative diameter of the descending aorta was 49.1 ± 12.9 mm (range 74.7-29.7 mm). Concomitant procedures included ascending aortic replacement in 16 patients; root replacement in 2; AVR in 2, CABG in 3 and mitral repair in 1 patient. CPB time was 263 ± 94 min; mean duration of ACP was 65 ± 14 min. Two patients died on POD 8 and 78, respectively. Major adverse events included stroke (n = 1), resternotomy for bleeding (n = 2), renal failure requiring temporary dialysis (n = 1) and recurrent nerve paresis (n = 2). After a mean follow-up of 10 ± 8 months, all discharged patients were alive. Seven patients underwent stent-graft implantation of the descending aorta and one patient underwent open descending aortic replacement. The last generation of multi-branched arch prosthesis and especially the Vascutek(®) Siena™ Collared Graft make ET procedure a reasonable treatment option even in patients with acute aortic dissection.

Elephant trunk in a small-calibre true lumen for chronic aortic dissection: cause of haemolytic anaemia?

OBJECTIVES

The elephant trunk technique for aortic dissection is useful for reducing false lumen pressure; however, a folded vascular prosthesis inside the aorta can cause haemolysis. The purpose of this study was to investigate whether an elephant trunk in a small-calibre lumen can cause haemolysis.

METHODS

Inpatient and outpatient records were retrospectively reviewed.

RESULTS

Two cases of haemolytic anaemia after aortic surgery using the elephant trunk technique were identified from 2011 to 2013. A 64-year-old man, who underwent graft replacement of the ascending aorta for acute Stanford type A aortic dissection, presented with enlargement of the chronic dissection of the descending aorta and moderate aortic regurgitation. A two-stage surgery was scheduled. Total arch replacement with an elephant trunk in the true lumen and concomitant aortic valve replacement were performed. Postoperatively, he developed severe haemolytic anaemia because of the folded elephant trunk. The anaemia improved after the second surgery, including graft replacement of the descending aorta. Similarly, a 61-year-old man, who underwent total arch replacement for acute Stanford type A aortic dissection, presented with enlargement of the chronic dissection of the descending aorta. Graft replacement of the descending aorta with an elephant trunk inserted into the true lumen was performed. The patient postoperatively developed haemolytic anaemia because of the folded elephant trunk, which improved after additional stent grafting into the elephant trunk.

CONCLUSIONS

A folded elephant trunk in a small-calibre lumen can cause haemolysis. Therefore, inserting an elephant trunk in a small-calibre true lumen during surgery for chronic aortic dissection should be avoided.

Utility of the Penn classification in predicting outcomes of surgery for acute type a aortic dissection

The Penn classification, a risk assessment system for acute type A aortic dissection (AAAD), is based on preoperative ischemic conditions. We investigated whether Penn classes predict outcomes after surgery for AAAD. Three hundred fifty-one patients with DeBakey type I AAAD treated surgically, January 1997 to January 2011, were divided into 4 groups per Penn class: Aa (no ischemia, n = 187), Ab (localized ischemia with branch malperfusion, n = 67), Ac (generalized ischemia with circulatory collapse, n = 46), and Abc (localized and generalized ischemia, n = 51). Early and late outcomes were compared between groups. In-hospital mortality was 3% (6 of 187) for Penn Aa, 6% (4 of 67) for Penn Ab, 17% (8 of 46) for Penn Ac, and 22% (11 of 51) for Penn Abc. Multivariate logistic regression analysis showed Penn classes Ac and Abc, operation time >6 hours, and entry in the descending thoracic aorta to be risk factors for in-hospital mortality. Incidences of neurologic, respiratory, and hepatic complications differed between groups. Five-year cumulative survival was 85% in the Penn Aa group, 74% in the Penn Ab group (p = 0.027 vs Penn Aa), 78% in the Penn Ac group, and 67% in the Penn Abc group (p <0.001 vs Penn Aa). In conclusion, morbidity and mortality are high in patients with generalized ischemia. The Penn classification appears to be a useful risk assessment system for AAAD, predictive of outcomes.

Acute Type-A aortic dissection with patent false lumen through to the abdominal aorta: effects of a conventional elephant trunk on malperfusion syndromes and narrowed true lumen

Background:

Narrowed true lumen and patent false lumen through to the terminal aorta is a high-risk condition for malperfusion syndromes (MS) in acute type-A aortic dissection. It is important to ascertain how the true and false lumens behave after surgery.

Patients and Methods:

We retrospectively investigated 45 patients with this pathology. The true lumen sizes at the narrowest levels above and below the superior mesenteric artery were followed by computed tomography after surgery (0-36 months).

Results:

Thirty-seven MS were seen in 23 patients. Hospital mortality was 8.9%. The narrowed true lumen was not enlarged in the first 6 months with a patent false lumen. The elephant trunk procedure did not improve the true lumen size. An extremely narrowed (≤3mm) true lumen was associated with a significantly high incidence of MS and mortality.

Conclusions:

High incidences of MS were observed in this particular pathology. An extremely narrowed true lumen was accompanied by a high incidence of MS and mortality.

Early and Mid-term Changes of the Distal Aorta after Total Arch Replacement for Acute Type A Aortic Dissection

Background

Total arch replacement (TAR) is being more widely performed due to recent advances in operative techniques and cerebral protective strategies. In this study, the authors reviewed the relationship between TAR and early- and mid-term changes of the false lumen after TAR in acute type A aortic dissection.

Materials and Methods

Twenty-six patients (aged, 54.7±13.3 years) who underwent TAR for acute type A dissection between June 2004 and February 2012 were reviewed. The relationship between the percentage change in the aortic diameter and the false lumen patency status was assessed by examining the early and late postoperative computed tomography imaging studies.

Results

There were two in-hospital mortalities, one late death, and three follow-up loses. The mean follow-up duration for the final 21 patients studied was 54±19.0 months (range, 20 to 82 months). The incidence of false lumen thrombosis within 2 weeks of surgery in the proximal, middle, and distal thoracic aorta, and the suprarenal and infrarenal abdominal aorta were 67%, 38%, 38%, 48%, and 33%, respectively, and 57%, 67%, 52%, 33%, and 33% for those examined at a mean of 49±18 months after surgery, respectively. The false lumen regressed in 11 patients (42.3%). The aortic diameters were larger in the patients with a patent false lumen than those with a thrombosed false lumen at all levels of the descending aorta (p<0.05).

Conclusion

TAR and a more complete primary tear-resection can be accomplished with a relatively low-risk of morbidity and mortality. Enlargement of the distal aorta significantly correlated with the false lumen patency status.

Descending aortic aneurysmal changes following surgery for acute DeBakey type I aortic dissection

OBJECTIVE

The aim of the study was to determine the risk factors for descending aortic aneurysmal changes following surgery for acute DeBakey type I aortic dissection.

METHODS

A total of 129 patients who underwent surgery for acute type I aortic dissection between 2000 and 2010 were evaluated by contrast-enhanced computed tomography (CT) at least 6 months later (median follow-up 29.5 months, interquartile range 16.3-49.3 months). The study endpoint was the development of aortic aneurysms (diameter >55 mm). Risk factors for aortic aneurysms were determined by Cox regression analysis.

RESULTS

Aortic dilatation occurred in 23 of the 129 (17.8%) patients. Aortic aneurysms were observed at the proximal descending in 19 (14.7%) patients, the mid descending in 12 (9.3%) patients, the distal descending in seven (5.4%) patients and at the abdominal aorta in one (0.8%) patient. Multivariate analysis showed that the luminal diameter of the proximal descending aorta on initial CT was the only significant and independent factor predicting aneurysm formation (hazard ratio 1.12, 95% confidence interval [CI] 1.02-1.22, P = 0.014). Receiver operating curves assessing the ability of preoperative proximal descending aorta diameter to predict aortic aneurysms showed an area under the curve of 0.72 (95% CI 0.60-0.84, P = 0.001), with a greatest accuracy at 40.95 mm (sensitivity 65.2%, specificity 78.3%). The 5-year freedom from aortic aneurysm rates in patients with proximal descending diameters ≤ 40 and >40 mm were 84.4 ± 6.6 and 55.6 ± 11.1%, respectively (P = 0.001).

CONCLUSIONS

The proximal descending aorta was the major site of aneurysm formation following surgery for acute type I aortic dissection. The large proximal descending aortic diameter on initial CT predicted the late aneurysm, suggesting that adjunctive procedures combined with aortic replacement are needed to prevent the late aneurysm.