A modified frozen elephant trunk technique for acute Stanford type A aortic dissection

Surgical choice for the treatment of partial intestinal ischemic necrosis caused by acute type a aortic dissection combined with malperfusion of superior mesenteric artery

Acute type A aortic dissection is a severe cardiovascular disease characterized by rapid onset and high mortality. Traditionally, urgent open aortic repair is performed after admission to prevent aortic rupture and death. However, when combined with malperfusion syndrome, the low perfusion of the superior mesenteric artery can further lead to intestinal necrosis, significantly impacting the surgery's prognosis and potentially resulting in adverse consequences, bringing. This presents great significant challenges in treatment. Based on recent domestic and international research literature, this paper reviews the mechanism, current treatment approaches, and selection of surgical methods for poor organ perfusion caused by acute type A aortic dissection. The literature review findings suggest that central aortic repair can be employed for the treatment of acute type A aortic dissection with inadequate perfusion of the superior mesenteric artery. The superior mesenteric artery can be windowed and (/or) stented, followed by delayed aortic repair. Priority should be given to revascularization of the superior mesenteric artery, followed by central aortic repair. During central aortic repair, direct blood perfusion should be performed on the distal true lumen of the superior mesenteric artery, leading to resulting in favorable therapeutic outcomes. The research results indicate that even after surgical aortic repair, intestinal ischemic necrosis may still occur. In such cases, prompt laparotomy and necessary necrotic bowel resection are crucial for saving the patient's life.

Strategy for acute DeBakey type I aortic dissection considering midterm results: a retrospective cohort study comparing ascending aortic replacement and total arch replacement with frozen elephant trunk technique

BACKGROUND

Acute type A aortic dissection is treated with an emergency procedure that uses ascending aortic replacement (AAR). However, to avoid a residual dissected aorta with a false lumen, total arch replacement (TAR) is required. The frozen elephant trunk (FET) technique is a promising surgical approach that promotes false lumen obliteration in a single step. Therefore, this retrospective single-center study aimed to evaluate the operative outcomes of AAR and TAR with FET.

METHODS

Between 2007 and 2021, 143 patients with acute DeBakey type I aortic dissection underwent a central repair using AAR (n = 95) or TAR with FET (n = 43). All perioperative variables, the duration of all-cause mortality, and aortic events defined as dilatation of the distal aorta > 5 cm, new occurrences of aortic dissection, distal aortic surgery, and distal aortic rupture were recorded. We compared these perioperative variables and mid-term results with an additional focus on distal aortic events.

RESULTS

Patient background data did not differ between the two groups. Perioperative results for the TAR with FET group vs the AAR group showed similar operative times (306 vs 298 min, P = 0.862), but the TAR group had longer cardiopulmonary bypass times (154 vs 179 min, P < 0.001). The freedom from all-cause death for the TAR vs AAR groups using the Kaplan-Meier method was 81.9% vs 85.4% and 78.0% vs 85.4% (P = 0.407) at 1 and 3 years, respectively. Freedom from aorta-related events was 90.6% vs 97.6% and 69.3% vs 87.0% (P = 0.034) at 1 and 3 years, respectively.

CONCLUSIONS

TAR with FET had comparable perioperative results to AAR in acute DeBakey type I aortic dissection and was considered a valuable method to avoid aorta-related events in the midterm.

Evidence-based frozen elephant trunk practice: a narrative review

Background and Objective

The frozen elephant trunk (FET) allows a single-stage repair of complex arch pathologies due to its stented and non-stented hybrid prosthesis (HP) features. FET inherently has its own related complications including distal stent graft-induced new entry (dSINE), failure of aortic remodelling, endoleak, reintervention, and kinking of the stent. The aim of this narrative review is to discuss the latest evidence regarding the postoperative clinical outcomes of the FET procedure. Another aim is to provide an overview of results achieved using different FET devices on the global arch prostheses market.

Methods

A comprehensive literature search was conducted using multiple electronic databases to identify and extract the relevant data and information.

Key Content and Findings

This review found that the literature reported a 5-12% mortality rate post-FET, with varying figures depending on the prosthesis type. Between 0-18.2% of patients developed dSINE, while 0.1-28% developed endoleak. Reintervention occurred in 0-28% of patients and the incidence of kinking has been quoted between 0-8% in the literature. Reporting aortic remodelling rates was challenging due to the lack of standardisation and various measurements reported; however, all studies included in this review reported relative increase in true lumen diameter, reduction in the false lumen diameter, and/or false lumen thrombosis.

Conclusions

In conclusion, FET can achieve a favourable postoperative profile in terms of survival, complications and aortic remodelling, and remains the gold-standard treatment for thoracic aortic pathologies implicating the arch and descending thoracic aorta.

Aortic remodeling in aortic dissection after frozen elephant trunk: overcoming the challenges

The introduction of the single-step hybrid frozen elephant trunk (FET) procedure expanded the surgeon's armamentarium in managing aortic dissection (AD). This is evident by the reduction in mortality and complication rates associated with conventional techniques used to repair ADs. Although FET still carries a risk of certain complications, it has been associated with excellent aortic remodeling following the procedure. The main scope of this review is to evaluate aortic remodeling in aortic dissection after FET as well as to highlight the challenges that may arise and ways to overcome them. A comprehensive literature search was conducted on multiple electronic databases including PubMed, Ovid, Scopus and Embase to highlight the evidence in the literature on aortic remodeling in aortic dissection after FET. The FET procedure promotes excellent long-term remodeling, this is seen in the substantial increase in the size of the true lumen along with the decrease in that of the false lumen (FL), in addition to significant FL thrombosis. However, this occurs to a lesser extent more distally at the level of the abdominal aorta. Negative remodeling may present a major challenge to the process of aortic remodeling, nevertheless, this can be overcome with endovascular reintervention which has demonstrated highly favorable results. Additionally, the choice of FET graft, in terms of type and length, seems to influence outcomes. Namely, the Thoraflex™ Hybrid graft can be considered the superior graft on the global market. On the other hand, there seems to be a debate in the literature on the optimal FET graft length. The FET procedure has revolutionized the field of aortovascular surgery and promotes excellent long-term aortic remodeling. Negative remodeling can occur but can also be favorably overcome with endovascular reintervention. Finally, the choice of FET graft may also influence results, thus, should be taken with great care.

What Is the Long-Term Clinical Efficacy of the Thoraflex™ Hybrid Prosthesis for Aortic Arch Repair?

Background

The widespread adoption of the frozen elephant trunk (FET) technique for total arch reconstruction (TAR) in aortic arch aneurysm and dissection has led to the development of numerous commercial single-piece FET devices, each with its own unique design features. One such device, Thoraflex™ Hybrid (Terumo Aortic, Glasgow, Scotland), has enjoyed widespread use since its introduction. We present and appraisal of its long-term clinical efficacy, based on international data.

Materials and Methods

Pre-, intra-, and postoperative data associated with Thoraflex™ Hybrid implantations for aortic arch dissection, aneurysm, and penetrating atherosclerotic ulcer (PAU) up to April 2019 was gathered and is presented herein. Follow-up data at discharge, 3-, 6-, 12-, 24-, 36-, 48-, 60-, 72-, and 84- months post-implantation are included.

Results

Data associated with 931 cases of Thoraflex™ Hybrid implantation are included. Mean age at implantation was 63 ± 12 years. 55% of patients included were male. Aortic dissection accounted for 48% (n = 464) of cases. Mean cardiopulmonary bypass and circulatory arrest durations were 202 +72 and 69 ± 50 min, respectively. 30-day mortality was 0.6% (n = 6), while overall mortality was 14 (1.5%). Freedom from adverse events at 84 months was 95% (n = 869). Postoperative complications included neurological deficit, multi-organ failure, cardiorespiratory compromise, and infection.

Discussion

Thoraflex™ Hybrid's unique design is advantageous in comparison to market alternatives. Our data is consistent with that reported in literature and suggests Thoraflex™ Hybrid is associated with favourable rates of mortality and morbidity.

Conclusion

Thoraflex™ Hybrid remains a central player in the aortic arch prosthesis market. Its use it widespread and is associated with favourable design features and clinical outcomes relative to market alternatives.

Incidence of Distal Stent Graft Induced New Entry vs. Aortic Remodeling Associated With Frozen Elephant Trunk

Background

The introduction of the frozen elephant trunk (FET) technique for total arch replacement (TAR) has revolutionized the field of aortivascular surgery by allowing hybrid repair of complex aortic pathologies in a single step through combining an open surgical approach with an endovascular one. FET has been associated with favorable aortic remodeling, however, its is also associated with development of distal stent graft induced new entry (dSINE) tears postoperatively. The rate of aortic remodeling and the incidence of dSINE have been linked together, in addition, there seems to be a relationship between these two variables and FET insetion length as well as graft size.

Aims

The scope of this review is to highlight the rate of aortic remodeling as well the incidence of dSINE associated with different FET devices available commercially. This review also aimed to investigate the relationship between aortic remodeling, dSINE, FET insertion length and FET graft size.

Methods

We conducted a comprehensive literature search using multiple electronic databases including PubMed, Ovid, Scopus and Embase in order to collate all research evidence on the above mentioned variables.

Results

Thoraflex™ Hybrid Plexus seems to yield optimum aortic remodeling by promoting maximum false thrombosis as well true lumen expansion. Thoraflex Hybrid™ is also associated with the lowest incidence of dSINE post-FET relative to the other FET devices on the market. Aortic remodeling and dSINE do influence each other and are both linked with FET graft length and size.

Conclusion

The FET technique for TAR shows excellent aortic remodeling but is associated with a considerable risk of dSINE development. However, Thoraflex™ Hybrid has demonstrated itself to be the superior FET device on the aortic arch prostheses market. Since aortic remodeling, dSINE, FET insertion length and stent graft size are all interconnect, the choice of FET device length and size must be made with great care for optimum results.

Aortic remodelling and false lumen changes after the frozen elephant trunk technique using the thoraflex hybrid stented graft for aortic dissection

Background

Despite the marked improvement in the aortic dissection repair techniques, residual dissected aorta with a patent false lumen remains an issue. So, the aim of our study is to observe the effect of inserting the Thoraflex Hybrid Graft on the aortic diameters in patients with type A aortic dissection involving the arch and descending aorta. Patients with type I aortic dissection who had aortic dissection repair using the Thoraflex Hybrid Graft in University Hospitals Birmingham were studied. Radiological assessment with computed tomography of the aorta was done at the level of the diaphragm to measure the true lumen, false lumen and total aortic diameters. Significance of change of diameters at early post-operative as compared to the pre-operative period was analysed.

Results

Eight cases were done in the acute setting, while 14 cases were done in the chronic setting. The ratio of true lumen to the total aortic diameter has significantly increased in the follow-up period as compared to the pre-operative period (P = 0.031). Whereas false lumen to total aortic diameter ratio has significantly decreased (P = 0.024). Subgroup analysis revealed that these changes were not significantly altered by whether the dissection was acute or chronic.

Conclusions

The Thoraflex Hybrid Graft will induce positive aortic remodelling with expansion of true lumen and will diminish the false lumen. But we could not find a significant difference between acute or chronic cases due to small sample size.

CT of Postoperative Repair of the Ascending Aorta and Aortic Arch

While many of the classic open surgical repairs are still used to repair the ascending aorta, management of the aortic arch has become more complex via implementation of newer open surgical and endovascular techniques. Furthermore, techniques are often combined in novel repairs or to allow extended anatomic coverage. As such, a framework that rests on understanding the expected postoperative appearance is necessary for the diagnostic radiologist to best interpret CT studies in these patients. After reviewing the imaging appearances of the common components used in proximal aortic repair, the authors present a structured approach that focuses on the key relevant questions that diagnostic radiologists should consider when interpreting CT studies in these patients. For repair of the ascending aorta, this includes determining whether the aortic valve has been repaired, whether the sinuses of Valsalva have been repaired, and how the coronary arteries were managed, when necessary. In repairs that involve the aortic arch, the relevant considerations relate to management of the arch vessels and the distal extent of the repair. In focusing on these questions, the diagnostic radiologist will be able to identify and describe the vast majority of repairs. Understanding these questions will also facilitate improved understanding of novel repairs, which often use these basic building blocks. Finally, complications-which typically involve infection, noninfectious repair breakdown, hemorrhage, problems with endografts, or disease of the remaining adjacent aorta-will be identifiable as deviations from the expected postoperative appearance. Online supplemental material is available for this article. ^©RSNA, 2021.