Thoracic endovascular aortic repair completion following frozen elephant trunk: how it's done and device selection

INTRODUCTION

Since its introduction in the mid-1990s the frozen elephant trunk (FET) technique has quickly evolved into an effective hybrid treatment option for patients with various thoracic aortic pathologies, acute and chronic. However, a notable incidence of and risk for distal aortic reinterventions persists after the implementation of the FET device. In this review, the authors analyze the indications and outcomes of thoracic endovascular aortic repair completion following FET.

AREAS COVERED

For this review, we looked not only at our own data but also searched PubMed for relevant studies, comments, and current recommendations of the European Association for Cardio-Thoracic Surgery (EACTS) and the European Society for Vascular Surgery (ESVS). Additionally, we outline our approach in this 2-stage-treatment plan.

EXPERT OPINION

The treatment of acute or chronic aortic pathologies involving the aortic arch frequently requires a 2-stage treatment approach. Sometimes, a tertiary procedure is needed to fix the entire aortic pathology. Thoracic endovascular aortic repair completion following FET requires careful planning to achieve the excellent clinical outcomes that we and numerous other aortic centers have shown. Only a dedicated aortic clinic provides the long-term continuous follow-up required to identify the few patients in need of a tertiary procedure.

Frozen elephant use in type a dissection: fundamentals, innovations, and pitfalls

INTRODUCTION

Type A acute aortic dissection (TA-AAD) is a great challenge for aortic surgeons. The establishment of a standardized surgical approach, particularly the determination of whether and when to address the aortic arch and the distal aorta in the same operation as the proximal aorta, is still unclear.

AREAS COVERED

Frozen elephant trunk (FET) has emerged as a valuable treatment for TA-AAD over the last decade. Here, we discuss the fundamentals and pitfalls of frozen elephant trunk procedures and present the latest innovations.

EXPERT OPINION

FET has the potential to simplify arch reconstruction in patients with complex arch tears and rupture, optimize perfusion in the distal true lumen for those with a compressed true lumen and malperfusion, address distal reentry tears, and promote false lumen thrombosis and late aortic remodeling. Nevertheless, FET is still associated with non-negligible mortality and morbidity rates. Patient selection, surgical expertise, and postoperative care remain crucial determinants in ensuring successful outcomes. Recent innovations in FET surgery involve the development of techniques to minimize or avoid hypothermic circulatory arrest and new FET devices with different arch branch configurations aiming to facilitate subsequent aortic reinterventions. We believe that both these advancements have the potential to improve patient outcomes.

Open, endovascular or hybrid repair of aortic arch disease: narrative review of diverse strategies with diverse options

OBJECTIVES

The management of aortic arch disease is complex. Open surgical management continues to evolve, and the introduction of endovascular repair is revolutionizing aortic arch surgery. Although these innovative techniques have generated the opportunity for better outcomes in select patients, they have also introduced confusion and uncertainty regarding best practices.

METHODS

In New York, we developed a collaborative group, the New York Aortic Consortium, as a means of cross-linking knowledge and working together to better understand and treat aortic disease. In our meeting in May 2023, regional aortic experts and invited international experts discussed the contemporary management of aortic arch disease, differences in interpretation of the available literature and the integration of endovascular technology into disease management. We summarized the current state of aortic arch surgery in this review article.

RESULTS

Approaches to aortic arch repair have evolved substantially, whether it be methods to reduce cerebral ischaemia, improve haemostasis, simplify future operations or expand options for high-risk patients with endovascular approaches. However, the transverse aortic arch remains challenging to repair. Among our collaborative group of cardiac/aortic surgeons, we discovered a wide disparity in our practice patterns and our management strategies of patients with aortic arch disease.

CONCLUSIONS

It is important to build unique institutional expertise in the context of complex and evolving management of aortic arch disease with open surgery, endovascular repair and hybrid approaches, tailored to the risk profiles and anatomical specifics of individual patients.

The Call for the "Interventional/Hybrid" Aortic Surgeon: Open, Endovascular, and Hybrid Therapies of the Aortic Arch

Aortic arch pathology is relatively rare but potentially highly fatal and associated with considerable comorbidity. Operative mortality and complication rates have improved over time but remain high. In response, aortic arch surgery is one of the most rapidly evolving areas of cardiac surgery in terms of surgical volume and improved outcomes. Moreover, there has been a surge in novel devices and techniques, many of which have been developed by or codeveloped with vascular surgeons and interventional radiologists. Nevertheless, the extent of arch surgery, the choice of nadir temperature, cannulation, and perfusion strategies, and the use of open, endovascular, or hybrid options vary according to country, centre, and surgeon. In this review article, we provide a technical overview of the surgical, total endovascular, and hybrid repair options for aortic arch pathology through historical developments and contemporary results. We highlight key information for surgeons, cardiologists, and trainees to understand the management of patients with aortic arch pathology. We conclude by discussing training paradigms, the role of aortic teams, and gaps in knowledge, arguing for the need for wire skills for the future "interventional aortic surgeon" and increased research into techniques and novel devices to continue improving outcomes for aortic arch surgery.

Trilateral versus Bilateral Antegrade Cerebral Perfusion in Frozen Elephant Trunk: A Propensity Score Analysis

OBJECTIVE

 Spinal cord injury (SCI) with subsequent paraplegia and/or stroke after arch repair with frozen elephant trunk (FET) remain the most devastating complications. In this study, we aim to examine the impact of different cerebral perfusion strategies on the neurological outcome comparing bilateral antegrade cerebral perfusion (bACP) and trilateral antegrade cerebral perfusion (tACP).

METHODS

 Between 2009 and 2021, 88 patients underwent total arch replacement using a hybrid prosthesis in FET technique for acute (40.4%) and chronic (59.6%) aortic pathologies. After excluding 14 patients who underwent FET with unilateral ACP the remaining 74 patients were divided into two groups. Propensity score matching was performed based on pre- and perioperative patient characteristics resulting in 22 patients in each group. The primary endpoint was a combination of major cerebral event and SCI. Secondary end point was all-cause mortality.

RESULTS

 Major cerebral events occurred in 9% of the patients in bACP versus 13.6% in tACP group (p = 0.63). No postoperative SCI was observed in patients with bACP and only one patient suffered SCI with tACP (p = 0.31). There was no significant difference in 30-day mortality between the two groups (22.7% in bACP vs. 13.6% in tACP; p = 0.43).

CONCLUSION

 In patients undergoing total aortic arch repair using FET technique, both perfusion strategies (bilateral and trilateral ACP) are safe and effective. The rates of neurological complications as well as mortalities are acceptably low in both groups. Further studies with larger patient cohorts are warranted.

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.

Overview of acute type A dissection in Japan

Acute type A aortic dissection is a relatively uncommon but devastating disease and usually requires emergency surgery. Based on the several database projects, a large amount of perioperative patient data has now been accumulated and is expected to be useful in clinical practice. Especially in Japan, the number of surgeries for acute type A aortic dissection has been gradually increasing recently, and the overall mortality rate has stabilized at less than 10%. One of the keys to further improvement in outcomes will be to improve the results of aortic root replacement. In addition, strategies need to be established for very elderly patients, comatose patients, and patients with malperfusion as preoperative conditions. The use of a relatively new device, the frozen elephant trunk, is also increasing and might be changing the surgical outcome. In this report, we describe the current status of acute type A aortic dissection in Japan, with reference to recent guidelines and literature.

Distal Stent Graft-Induced New Entry After Frozen Elephant Trunk Procedure for Aortic Dissection

BACKGROUND

The purpose of this study was to evaluate the risk factors of distal stent graft-induced new entry (dSINE) after frozen elephant trunk (FET) procedure for aortic dissection (AD) and to consider strategies to prevent this complication.

METHODS

This retrospective review included 52 patients who had undergone aortic arch repair for AD with the FET procedure using J Graft FROZENIX from 2014 to 2020 at a single center. Baseline characteristics, aortic characteristics and mid-term outcomes were compared between patients with and without dSINE. The extent of unfolding of the device and movement of the distal edge of the device were analyzed by multidetector computed tomography. The primary endpoints were survival and freedom from reintervention.

RESULTS

dSINE was the most prevalent complication after FET procedure, with an incidence of 23%. Eleven of 12 patients with dSINE underwent secondary interventions. dSINE was common in chronic aortic dissection (P = 0.001) and was associated with the residual false lumen area (P < 0.001) and movement distance of the distal edge of the device in the cranial direction (P < 0.001).

CONCLUSIONS

The distal edge of the FET is more likely to move in the cranial direction, and this movement may cause dSINE.

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

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

False lumen-dependent segmental arteries are associated with spinal cord injury in frozen elephant trunk procedure for acute type I aortic dissection

Objective

To investigate the association between false lumen (FL) dependency of segmental arteries (SAs) at T9-L3 levels and the risk of spinal cord injury (SCI) following total arch replacement and frozen elephant trunk (FET) implantation in the setting of acute DeBakey type I aortic dissection (AAD).

Methods

The study involved consecutive patients with AAD who underwent total arch replacement and FET implantation between 2020 and 2022. Primary outcome was postoperative SCI. The inverse probability of treatment weighting (IPTW) method was employed to minimize the impact of no-randomization bias. Antegrade placement of FET was followed by end-to-end anastomosis of a 4-branch arch graft at the proximal landing site of FET.

Results

A total of 146 patients were included (age, 50.5 ± 11.7 years, 115 male), of whom 35 (24%) had SAs at T9-L3 levels completely dependent on FL (FL-dependency group). There was no significant difference in early (30-day or in-hospital) mortality rates between FL-dependency (14.3%) and FL-independency (18.0%) groups (P = .80), however, the rate of SCI was significantly higher in the FL-Dependency group (34.3% vs 2.7%, P < .001). After adjustments, FL dependency was associated with a significantly increased risk of SCI (odds ratio, 13.1; 95% confidence interval, 4.2-41.0; P < .001), whereas it was not significantly associated with risks of early mortality or other major complications (P = .16-.98).

Conclusions

FL dependency of SAs at the T9-L3 levels was significantly associated with the development of SCI following FET implantation in AAD, warning against its uses on patients presenting with FL dependency of SAs at critical segments.

Intermediate outcomes following arch reconstruction with frozen elephant trunk, a single centre study

BACKGROUND

Surgery on the aortic arch and proximal descending thoracic aorta can be lifesaving but is also associated with significant morbidity, ranging from minor infections to severe neurological impairments as well as a substantial risk of mortality. The aim of this study is to clinically assess outcomes, with special regards to neurologic injury, as well as to seek to identify predictors of in-hospital mortality in two patient groups with different underlying aortic pathology, aneurysms and dissections, undergoing arch/descending aortic repair.

METHODS

34 patients (17 aneurysms, 17 dissections) underwent surgery involving the arch and/or descending aorta, using the Thoraflex or E-Vita frozen elephant trunk graft. 40% were female. Subgroup analysis of aneurysms compared to dissections were performed. Mean follow-up time was 53.9 months and mean age 63.5 years.

RESULTS

In-hospital mortality was 18%. Survival was comparable between aneurysms and dissections. Incidence of spinal cord injury was 9% and stroke 9%. 67% suffered any form of neurological affection, when also cognitive afflictions were included. Perioperative reoperation rate was 29% (bleeding 21%, visceral ischemia 6%, infection 2%), the need for postoperative dialysis was 11% and a series of other minor complications such as atrial fibrillation and pleurocentesis were common.

CONCLUSION

Postoperative dialysis was found to be a predictor of in-hospital mortality, while both dialysis as well as reoperation due to bleeding and/or visceral ischemia increased the risk for overall mortality, irrespective of preoperative diagnosis. Previous or current smoking appeared to be associated with negative outcomes regarding both in-hospital and overall mortality during follow-up. Trial registration Retrospectively enrolled.

Surgical Approaches to Single-Stage Extended Aortic Repair from the Ascending to the Distal Descending Aorta

Single-stage extended replacement from the ascending to the distal descending aorta or beyond is a formidable operation that should be preserved for those who have no other option or those who are physically fit, and should be performed in the experienced centers. Hybrid operations combining open surgical repair with thoracic endovascular aortic repair through a median sternotomy incision are preferable because these operations are less invasive than the extended open aortic repair and the risk of spinal cord ischemia is lower compared with the frozen elephant trunk operation. However, these operations are associated with the inherent demerits of endovascular aneurysm exclusion. When the underlying aortic pathology necessitates extended open aortic repair in a single stage, approaches such as the anterolateral partial sternotomy, straight incision with rib cross, and extended thoracotomy with sternal transection may be useful to provide sufficient exposure for both aortic reconstruction and organ protection, with less surgical stress to the patients.

Is open triple-branched stent graft the next stage?

Due to the pathology of acute type A aortic dissection (AAD), including fragile dissected aortic wall and visceral malperfusions, surgical procedures are still in development. This commentary is a review of a report by Bin and Yang et al. published in the Journal of Cardiac Surgery that reported similar effectiveness of the open triple-branched stent graft for acute type AAD and total arch replacement with the frozen elephant trunk technique.

Left Subclavian Artery Sacrifice in Acute Aortic Dissection Repair using the Frozen Elephant Trunk

OBJECTIVE

Surgery of acute aortic dissection using the frozen elephant trunk (FET) can be complicated when the origin of the left subclavian artery (LSA) is dissected and sacrifice by ligation is a viable option. However, the LSA is supposed to play a role in neuroprotection as a major collateral. We, therefore, analyzed our results of LSA sacrifice in this cohort.

METHODS

We identified a total of 84 patients from our prospectively collected database who underwent FET repair of acute aortic dissection between October 2009 and April 2018. LSA was sacrificed in 19 patients (22.6%). Results were analyzed and compared with regard to neurological outcomes.

RESULTS

New postoperative stroke was seen in two patients (2.4%) and spinal cord injury in three patients (3.6%) overall, none in the LSA-sacrifice group. We observed a temporary neurological deficit in five patients (6.0%) overall, none in the LSA-sacrifice group. None of the patients developed acute ischemia of the left arm. Only two patients (12.5%) came back for carotid-subclavian artery bypass due to exertion-induced weakness of the left arm 3 to 4 months after the initial surgery. In-hospital mortality was 15.5% overall, with no difference between groups.

CONCLUSION

LSA sacrifice was not associated with elevated postoperative risk of either central or spinal neurological injury. Thus, it can facilitate FET repair of acute aortic dissection in selected cases when the left subclavian origin cannot be preserved. Carotid-subclavian artery bypass became necessary in only a small fraction of these patients and can be performed as a second-stage procedure.

Analysis of Spinal Ischemia after Frozen Elephant Trunk for Acute Aortic Dissection: An Observational, Single-Center Study

BACKGROUND

This observational study aimed to evaluate the perioperative risk factors for spinal cord ischemia (SCI) in patients who underwent aortic repair with the frozen elephant trunk technique (FET) after acute aortic Stanford A dissection.

METHODS

From May 2015 to April 2019, 31 patients underwent aortic arch replacement with the FET technique, and spinal ischemia was observed in 4 patients. The risk factors for postoperative SCI were analyzed.

RESULTS

The mean age of patients with acute aortic dissection was 57.1 years, and 29.4% were female. Four patients developed SCI. There were no significant differences in characteristics such as age and body mass index. The female gender was associated with most of the SCI cases in the univariate analysis (75%, p = 0.016). Known perioperative and intraoperative risk factors were not related to postoperative SCI in our study. Patients who developed SCI had increased serum postoperative creatinine levels (p = 0.03). Twenty-four patients showed complete false lumen thrombosis up to zones 3-4, five patients up to zones 5-6 and two patients up to zones 7-9, which correlates with the postoperative development of SCI (p = 0.02). The total number of patent intercostal arteries was significantly reduced postoperatively in SCI patients (p = 0.044).

CONCLUSIONS

Postoperative acute kidney injury, the reduction in patent intercostal arteries after surgery and the extension of false lumen thrombosis up to and beyond zone 5 may play a significant role in the development of clinically relevant spinal cord injury after FET.

Two-stage aortic surgery for distal aortic arch and descending aorta aneurysms: A case report

RATIONALE

Although surgical treatment strategies for patients with extensive thoracic aortic disease involving the aortic arch have improved considerably, the impact of stent graft length and placement site on aortic remodeling at long-term follow-up is not fully understood, and the protection of the Adamkiewicz artery (AKA) using the frozen elephant trunk (FET) method is also unclear.

PATIENT CONCERNS

The patient was a 69-year-old man with diabetic nephropathy who became increasingly fatigued and started maintenance hemodialysis 6 months prior to admission. At 64 years, he underwent clipping of a right cerebellar artery aneurysm. In addition, a 1.8 cm aneurysm was found in the contralateral extracranial internal carotid artery. He also had an atrial septal defect and moderate aortic regurgitation and was receiving continuous positive airway pressure therapy for sleep apnoea syndrome.

DIAGNOSIS

He had aneurysms in the aortic arch (4.8 cm in diameter) and descending aorta (6 cm in diameter), which was located at T6-9. Preoperative 3-dimensional computed tomography showed that the (AKA) bifurcated at T10-11.

INTERVENTIONS

Considering the patient's several comorbidities and frailty, we planned to perform 1-stage extended aortic arch repair using the FET procedure. However, we performed 2-stage aortic surgery to prevent spinal ischemia, anticipating substantial cardiac enlargement and blood pressure instability due to dialysis treatment. Aortic valve replacement, atrial septal defect patch closure, and aortic arch surgery were performed. A 7-cm elephant trunk was inserted in the descending aorta. Postoperatively, the patient continued rehabilitation until his blood pressure stabilized during dialysis therapy. At postoperative week 4, he underwent thoracic endovascular aortic repair for a descending aortic aneurysm.

OUTCOMES

After surgery, his physical strength decreased; however, he recovered and was discharged 1 month later without any complications. One year after the second operation, he is living a healthy life.

LESSONS

Extensive aortic arch surgery using the FET procedure is effective for distal aortic arch and descending aortic aneurysms. Nevertheless, in cases in which the position of the AKA is close to the aortic aneurysm and blood pressure control is difficult, a 2-stage procedure and accurate positioning of thoracic endovascular aortic repair are both desirable.

Novel technique in frozen elephant trunk positioning method using the ostium of the coronary artery on transesophageal echocardiography as an index

The frozen elephant trunk (FET) technique is useful in the single-stage treatment of aortic arch aneurysms. Since there is no established implantation method for evaluating the distal end of the FET during surgery, we propose the FET positioning method using the ostium of the coronary artery on transesophageal echocardiography (TEE) as an index. We performed 11 total arch replacement operations using an FET for aortic arch aneurysm. The planned position of the FET was determined by computed tomography (CT), and the distance to the ostium of the coronary artery was measured. Intraoperatively, using TEE as a guide, the FET was implanted using our method. Postoperative CT was evaluated the distance from the planned FET position, and the average and median difference was only 0.96 cm and 0.6 cm, respectively. TEE-guided FET deployment using the coronary artery ostium as an index is a simple and reproducible technique.

Zone proximalization in frozen elephant trunk: what is the optimal zone for open intervention? A systematic review and meta-analysis

INTRODUCTION

The treatment of complex aortic lesions involving the ascending, arch, and proximal descending aorta, remains challenging for surgeons despite the evolution of surgical techniques and aortic prostheses over decades. The frozen elephant trunk (FET) approach offers a one-stage repair of this entity of aortic pathologies. The main scope of this systematic review and meta-analysis is to evaluate the clinical outcomes and effectiveness of FET.

EVIDENCE ACQUISITION

In a systematic review, multiple electronic databases including EMBASE, Scopus, and PubMed/MEDLINE were searched from inception to June 2021 to identify relevant studies reporting on outcomes of total arch replacement (TAR) with FET.

EVIDENCE SYNTHESIS

Eighty-five studies met inclusion criteria, encompassing 10960 patients. Meta-analysis was conducted using the R-studio (RStudio, Boston, MA, USA) and STATA software (StataCorp LLC, College Station, TX, USA). The pooled in-hospital mortality rate was 7% (95% CI 0.05-0.09; I²=76%) and 12% for renal failure (95% CI 0.09-0.15; I²=88%), while the rates for paraplegia and cerebrovascular accidents were 3% (95% CI 0.02-0.04; I²=0%) and 6% (95% CI 0.05-0.08; I²=73%), respectively. Lower heterogeneity was attained after the stratification by the aortic pathologies, except for the renal failure. The distal anastomosis of the stent in zone 2 was significantly correlated with a lower renal failure development compared to zone 3 (odds ratio 0.52; 95% CI 0.33-0.82; P=0.069; I²=0%).

CONCLUSIONS

Our results indicate that the morbidities and mortality following TAR with FET were acceptable. We also associated the distal anastomosis in zone 2 with fewer renal failure development compared to that in zone 3.

Early awaking of patients following FET allows early recognition of paraplegia with prospects for complete recovery using prompt spinal drainage

We report a patient who presented with paraplegia after ascending aorta and arch replacement using the frozen elephant trunk technique. Immediate postoperatively cerebrospinal fluid drainage allowed successful reversal of spinal cord injury. Early awakening of patients following a frozen elephant trunk technique is mandatory because it allows recognition and treatment of this complication by prompt cerebrospinal liquor drainage.

Systematic review and meta-analysis of association of prophylactic cerebrospinal fluid drainage in preventing spinal cord ischemia after thoracic endovascular aortic repair

OBJECTIVE

We conducted a systemic review and meta-analysis to compare the association between prophylactic cerebrospinal fluid drainage (CSFD) vs non-CSFD in preventing spinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR) for aneurysm and dissection.

METHODS

The MEDLINE, Embase, and Cochrane databases were systematically searched to identify all relevant studies reported before April 1, 2020. A systematic review and meta-analysis were performed. We assessed the association between CSFD strategies, including routine CSFD vs selective CSFD or no CSFD, and the SCI rates after TEVAR for patients with aortic dissection (AD), solitary thoracic aortic aneurysm (TAA), or thoracoabdominal aortic aneurysm (TAAA). Subgroup analyses were conducted to assess the association between different aortic pathologies, including AD and thoracic aneurysms, and SCI rates after TEVAR with and without prophylactic CSFD. The data are presented as the pooled event rates (ERs) and 95% confidence intervals (CIs).

RESULTS

A total of 34 studies of 3561 patients (2671 with TAA or TAAA and 890 with type B AD) were included in the present analysis. The data are presented as the pooled ERs and 95% CIs. The overall SCI rate for patients who had undergone TEVAR with prophylactic CSFD for AD (ER, 1.80%; 95% CI, 0.88%-2.72%) was significantly lower than that for the aortic aneurysm group (ER, 5.73%; 95% CI, 4.20%-7.27%; P < .0001). The SCI rate after TEVAR with prophylactic CSFD was not significantly different from that without CSFD for AD (P = .51). No association was found between the rates of SCI after TEVAR with routine prophylactic CSFD vs selective prophylactic CSFD for aortic aneurysms (P = .76) and AD (P = .70). The SCI rate after TEVAR without CSFD for aortic aneurysms, including isolated TAA and TAAA (ER, 3.49%; 95% CI, 0.23%-6.76%) was not significantly different from that for AD (ER, 3.20%; 95% CI, 0.00%-7.20%; P = .91). For the patients with TAAAs, the rate of SCI after TEVAR with routine prophylactic CSFD was significantly lower than that with selective prophylactic CSFD (P = .04).

CONCLUSIONS

Our systematic review and meta-analysis has shown that SCI occurs more often after TEVAR for aortic aneurysms than for AD. Routine prophylactic CSFD, compared with selective CSFD, was associated with a lower rate of postoperative SCI after TEVAR for TAAAs. No significant association was found between the SCI rate and routine prophylactic CSFD for patients undergoing TEVAR for isolated TAA or AD.

Frozen elephant trunk procedure for complex aortic arch surgery: The Salerno experience with Thoraflex hybrid

Background and Aim of the Study

To report early clinical outcomes of the frozen elephant trunk (FET) technique for the treatment of complex aortic diseases after transition from conventional elephant trunk.

Methods

A single‐center, retrospective study of patients who underwent hybrid aortic arch and FET repair for aortic arch and/or proximal descending aortic aneurysms, acute and chronic Stanford type A aortic dissection with arch and/or proximal descending involvement, Stanford type B acute and chronic aortic dissections with retrograde aortic arch involvement.

Results

Between December 2017 and May 2020, 70 consecutive patients (62.7 ± 10.6 years, 59 male) were treated: 41 (58.6%) for emergent conditions and 29 (41.4%) for elective. Technical success was 100%. In‐hospital mortality was 14.2% (n = 12, 17.1% emergent vs. 10.3% elective, P = NS); 2 (2.9%) major strokes; 1 (1.4%) spinal cord injury. Mean follow‐up was 12.5 months (interquartile range, 3.7–22.3). Overall survival at 3, 6, 12, and 24 months was 90% (95% confidence interval [CI], 83.2—97.3), 85.6% (95% CI, 77.7–94.3), 79.1% (95% CI, 69.9–89.5), 75.6% (95% CI, 65.8–86.9) and 73.5% (95% CI, 63.3–85.3). There were no aortic re‐interventions and no distal stent graft‐induced new entry (dSINE); 5 patients with residual type B dissection underwent TEVAR completion.

Conclusions

In a real‐world setting, FET with Thoraflex Hybrid demonstrated feasibility and good clinical outcomes, even in emergent setting. Our implant technique optimize cerebral perfusion reporting good results in terms of neurological complications. Techniques to perfect the procedure and to reduce remaining risks, and consensus on considerations such as standardized cerebral protection need to be reported.

The zone 2 concept and distal stent graft positioning in TH 2-3 are associated with high rates of secondary aortic interventions in frozen elephant trunk surgery

OBJECTIVES

The goal of this study was to investigate the association between the localization of the distal anastomosis (zone 2/3), the stent graft length (100-160 mm), the position of the distal end of the hybrid prosthesis and the need for secondary aortic intervention (SAI) in acute and chronic thoracic aortic disease after the frozen elephant trunk procedure.

METHODS

From 2009 through 2020, a total of 232 patients (137 men; mean age, 61.7 ± 13.8 years) were treated with the frozen elephant trunk procedure. The main indications were acute aortic dissection type A (n = 106, 46%), chronic aortic dissection type A (n = 52, 22%) and degenerative thoracic aortic aneurysm (n = 74, 32%).

RESULTS

The rate of SAI was significantly higher when we performed a distal anastomosis in zone 2 rather than in zone 3, whereas the rate of SAI was less frequent if the distal positioning of the hybrid prosthesis was below TH 4-5. Combining the zone 2 concept and the short stent graft length (100 mm) was associated with a significantly higher rate of SAIs. Patients with a distal anastomosis in zone 2 were significantly less likely to have a recurrent laryngeal nerve injury (P < 0.001). However, no association between a specific arch zone of a distal anastomosis and the occurrence of spinal cord injury was observed.

CONCLUSIONS

Rates of SAIs are highest in patients who were treated with a distal anastomosis in zone 2 and a short stent graft (100 mm) with the distal end of the hybrid prosthesis at vertebral level TH 2-3.

Frozen elephant trunk usage in acute aortic dissection

This review discusses the clinical applications of the frozen elephant trunk procedure for patients with acute aortic dissection. Sub-analysis of the multicenter Japanese Frozenix study, J-ORCHESTRA, are presented, and recent reports of frozen elephant trunk usage for acute aortic dissection are discussed.

The frozen elephant trunk technique: impact of proximalization and the four-sites perfusion technique

 

OBJECTIVES

To improve organ protection with the frozen elephant trunk (FET) procedure, a so-called four-sites perfusion in combination with proximalization for the distal aortic anastomosis was performed. The impact of these techniques on patient outcome is reported.

METHODS

Between February 2005 and April 2020, a total of 357 patients underwent the FET procedure for acute (54%) or chronic (22%) aortic dissection or aneurysmal disease (24%). The level of the distal FET anastomosis was defined according to aortic arch zones 0–3. Patients were divided into 3 groups according to the intraoperative perfusion strategy: (i) selective antegrade cerebral perfusion (SACP) alone (N = 96, 2 sites); (ii) SACP plus left subclavian artery or distal aorta (N = 84, 3 sites) and (iii) SACP plus left subclavian artery plus distal aorta (N = 177, 4 sites). Early outcome was addressed by a composite end point: occurrence of either a disabling stroke, a disabling spinal cord injury, extracorporeal circulatory support, kidney dialysis or death within 90 days.

RESULTS

Preoperative characteristics were similar among the groups. Surgery in group C was characterized by FET proximalization in arch zone ≤2, moderate hypothermia at 28°C and shorter periods of extracorporeal circulation, SACP, hypothermic circulatory arrest and cardioplegic arrest (P < 0.001, respectively). Occurrence of the composite end point was reduced in group C (P = 0.008). The combination of FET proximalization and four-sites perfusion was a protective factor for the composite outcome in multivariable analysis (P = 0.009). The 5-year survival was improved in patients who underwent FET proximalization in zone ≤2 (hazard ratio 0.7, 95% confidence interval 0.4–1.0; P = 0.036).

CONCLUSIONS

FET proximalization in combination with four-sites perfusion has the potential to improve patient outcomes in terms of survival and major events.

Subject collection

120; 161.

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.

Frozen elephant trunk in total arch replacement: A systematic review and meta-analysis of outcomes and aortic proximalization

BACKGROUND AND AIM OF THE STUDY

The frozen elephant trunk (FET) procedure became a popular entity for utilization in aortic arch aneurysm disease. However, its proper mortality and morbidities as well as the predictors of outcomes are poorly identified. This systematic review and meta-analysis explore FET outcomes and its predictors with a focus on zone aortic proximalization.

METHODS

We searched PubMed/MEDLINE, EMBASE, and Scopus databases from their beginning to June 2020 to find studies reporting the outcomes of the FET procedure for the total arch replacement (TAR).

RESULTS

A total of 64 studies including 7967 patients were evaluated. The pooled estimates of cerebrovascular accidents, paraplegia, renal failure, and in-hospital mortality were 7.104 (95% confidence interval [CI], 5.691-8.661; I²  = 78.53%), 3.465 (95% CI, 2.852-4.136; I²  = 15.96), 14.969 (95% CI, 11.361-18.977; I²  = 91.26%), and 8.933 (95% CI, 7.128-10.919; I²  = 78.51%), respectively. Stratification by the geographical locations and by the aortic pathologies led to lower heterogeneity, but not for renal failure. The distal anastomosis in Zone 2 was associated with a lower rate of renal failure compared with Zone 3 (odds ratio, 0.54; 95% CI, 0.36-0.81; p = .003; I²  = 0%).

CONCLUSIONS

The FET procedure for TAR can be performed with acceptable mortality and morbidities among patients with complex aortic pathologies. Moreover, the distal anastomosis in Zone 2 was associated with lower renal failure compared to Zone 3.

Review of frozen elephant trunk repair with the Thoraflex Hybrid device

The frozen elephant trunk technique has revolutionized aortic arch repair to enable more extensive arch and descending thoracic aortic treatment in a single setting. We review the current evidence supporting the use of the Thoraflex Hybrid (Terumo Aortic, FL, USA) device and discuss advantages, pitfalls and future design considerations.

Thoraflex hybrid as frozen elephant trunk in chronic, residual type A and chronic type B aortic dissection

OBJECTIVES

The frozen elephant trunk technique is an increasingly common treatment for extensive disease of the thoracic aorta. The objective of the study was to evaluate the outcomes of frozen elephant trunk specifically in chronic (residual) aortic dissections, focusing on downstream aortic remodelling.

METHODS

Between 2013 and 2019, a total of 28 patients were treated using the Vascutek Thoraflex hybrid graft at our institution for chronic dissections/post-dissection aneurysms. Immediate and follow-up outcomes were studied, as well as the changes in total aortic diameter, true lumen and false lumen diameter and the status of the false lumen at 3 different levels of the thoraco-abdominal aorta.

RESULTS

No in-hospital or 30-day mortality was observed, temporary paraparesis rate was 7% and disabling stroke incidence was 14.3%. Freedom from all-cause mortality at 2 years was 91.6 ± 5.7%, while freedom from reintervention on the downstream aorta at 2 years was 59.1 ± 10.8%. Positive aortic remodelling was achieved in 50.0%, with an enlargement in the true lumen and a reduction of the false lumen not only at the level of the proximal descending aorta with 73.1% of complete thrombosis but also at the level of the distal descending thoracic aorta, with 41.7% of complete thrombosis.

CONCLUSIONS

The frozen elephant trunk is a good solution in chronic (residual) downstream aortic dissections inducing positive aortic remodelling and preventing from II stage operations or allowing an endovascular approach.

[Present-day policy of surgical treatment for type A acute aortic dissection]

A surgical intervention for type A acute aortic dissection is the only effective method of treatment making it possible to prevent the development of life-threatening complications and to attain clinical recovery of the patient. Supracoronary replacement of the ascending aorta and the proximal portion of the aortic arch is considered to be the classical and most commonly used method of an open operative intervention. On the one hand, it is technically the simplest and shortest operation, and on the other, this surgical technique is often accompanied by long-term proximal and distal complications, and first of all those caused by a persistent false lumen. The accumulated surgical experience and contemporary operative techniques, as well as advances of intensive therapy in treatment of type A acute aortic dissection make it possible to currently perform more extensive primary resections in order to improve the remote results. Total aortic arch replacement, including the use of the 'frozen elephant trunk' technique leads to fast thrombosis of the false lumen, preventing progression of the disease of the thoracic aorta and promoting its positive remodelling. The article describes the perioperative therapeutic policy accepted and pursued in our medical facility, also presenting the authors' opinion on the role and place of the 'frozen elephant trunk' technique in rendering medical care for patients with type A acute aortic dissection.

Early and mid-term outcome of frozen elephant trunk using spinal cord protective perfusion strategy for acute type A aortic dissection

OBJECTIVE

This study aimed to evaluate the prevalence of spinal cord injury in total arch replacement with frozen elephant trunk for acute type A aortic dissection using our spinal cord protection technique.

METHODS

Between January 2013 and December 2017, 33 patients underwent total arch replacement with frozen elephant trunk for acute type A aortic dissection (mean age 67.9 ± 13.3 years). Our spinal cord protection technique involved maintaining extracorporeal circulation through the left subclavian artery in all procedures, using aortic occlusion balloon during distal anastomosis, and inserting frozen elephant trunk above Th 8 with transesophageal echocardiographic guidance. Computed tomography was performed within 1-2 weeks, 12 months, and 36 months postoperatively. We compared the degree of thrombosis of the descending aorta between preoperation and early postoperative period by Fisher's exact test. Moreover, we evaluated postoperative mortality and mobility (including spinal cord injury) at follow-up.

RESULTS

The operative mortality within 30 days was 6.1%. Neither paraplegia nor paraparesis was noted. We observed significant thrombosis of the false lumen at the distal arch and aortic valve level of the descending aorta in postoperative early term period (p < 0.01). At mid-term follow-up (mean 33.9 months), survival probability and 3-year freedom from reoperation rates were 93.9 ± 4.1% and 95.0 ± 4.9%, respectively.

CONCLUSIONS

The frozen elephant trunk technique with our spinal protection strategy provides good postoperative outcomes. Our strategy can maintain spinal cord perfusion without complete ischemia time even during lower body ischemia time. Implementation of our spinal protection strategy will help prevent spinal cord injury and dilated downstream aorta.

Hybrid two-stage repair of Stanford A dissection with visceral or peripheral malperfusion

Background

The present study aimed to evaluate the effect of two-stage hybrid aortic repair at the distal aorta of Stanford A dissection with malperfusion.

Methods

This retrospective case series included 20 patients with Stanford A dissection administered two-stage thoracic endovascular aortic repair (TEVAR) about 1 month after central repair because of visceral or limb malperfusion. The patients were examined by computed tomography (CT) angiography at 3, 6, 12 and 24 months after operation. Recovery of malperfusion and true lumen index were evaluated during follow-up.

Results

Twenty patients underwent two-stage hybrid aortic repair, including 11 males and 9 females. The follow-up time was 24 ± 7 months. No intervention-related complications were observed, including stent graft-induced new re-entry tears, death, stroke and spinal cord injury. Malperfusion in all cases was corrected. The true lumen was not enlarged enough 1 month after the first surgery. Thrombosis of the false lumen was observed around the elephant trunk at the carina level and the celiac artery. Three months after second stage TEVAR, the false lumen thrombosis was resorbed; in addition, the trunk was fully expanded at the carina level, and the true lumen was enlarged at the celiac artery.

Conclusions

Two-stage hybrid aortic repair for residual true lumen in the distal aorta 1 month after initial surgery is helpful for descending aorta remodeling and effective in treating malperfusion. This procedure may be a good option for patients suffering from Stanford A dissection with small true lumen in the distal aorta and malperfusion.

Single-center experience and evolution of technique with the E-vita Open prosthesis

BACKGROUND

We report our experience in aortic arch repair with the E-vita Open hybrid prosthesis and describe the changes in our technique over time.

METHODS

Between October 2013 and December 2019, 56 patients underwent a total aortic arch replacement with the E-vita Open hybrid prosthesis. The main indications were thoracic aorta aneurysm (n = 27) and acute type A aortic dissection (n = 18). We analyze the technique and results in the overall series, and compare both between our early (group I, 25 patients) and late experience (group II, 31 patients).

RESULTS

Overall in-hospital mortality was 7.1% (n = 4), and permanent stroke and spinal cord injury were 3.6% and 1.8%, respectively. Fifteen patients (26.8%) underwent a planned second procedure on the distal aorta: 13 endovascular, 1 open, and 1 hybrid. Survival at 1 and 3 years was 90.7% and 80.7%, respectively. Group II included more patients with acute dissection (45.2% vs 16%, P = .02), higher rates of bilateral cerebral perfusion (100% vs 64%, P < .001), left subclavian artery perfusion during lower body circulatory arrest (87.1% vs 0%, P < .001), early reperfusion (96.8% vs 40%, P < .001), and zone 0 to 2 distal anastomosis (100% vs 72%, P = .02). In-hospital mortality (3.2% vs 12%) and permanent stroke (0% vs 8%) tended to be lower in group II.

CONCLUSIONS

Total arch replacement with E-vita Open hybrid prosthesis in complex thoracic aorta disease is safe. One-stage treatment is feasible when pathology does not extend beyond the proximal descending thoracic aorta. In any case, it facilitates subsequent procedures on distal aorta if needed.

Mid-Term Results of Frozen Elephant Trunk Technique for Chronic Aortic Dissection

Objective: In this study, we report our experience using the frozen elephant trunk (FET) technique for chronic aortic dissection. Methods: Between January 2011 and December 2017, 15 patients underwent total arch replacement (TAR) with the FET technique for chronic aortic dissection (CAD). Results: Hospital mortality was 6.7% (n=1). No patients experienced spinal cord injury. Distal stent-induced new entry (dSINE) occurred in the early postoperative period in one patient. There were four unplanned additional operations to manage dSINE. Five patients suffered from dSINE, and aortoesophageal fistula developed in three of them. Short insertion length of the FET and large angle between the distal edge of the FET and the descending aorta were significantly more common in the dSINE group than in the non-dSINE group. The cumulative survival rates at 1, 3, and 5 years were 93.3%, 93.3%, and 66.4%, respectively. The cumulative aortic event-free rates at 1, 2, and 3 years were 85.7%, 77.1%, and 52.9%, respectively. Conclusion: The FET technique for CAD provided good early results. Short insertion length of the FET, however, can induce dSINE, which requires an additional operation at mid-term. Thus, surgical indication of the FET technique for CAD must be discussed.

Tetraplegia after branched frozen elephant trunk implantation for acute type A aortic dissection

A 58-year-old male patient presented with acute type A aortic dissection. Complete arch and ascending aorta replacement were performed using a Thoraflex Hybrid prosthesis. The left subclavian artery was ligated and the remaining supra-aortic trunks were reimplanted using the branches of the prosthesis. After an uneventful early postoperative period, sudden onset of hypotension and bradycardia occurred, with severe vasoplegia, requiring vasopressors. Ischemia of the upper left limb and compartment syndrome ensued, leading to left carotid subclavian bypass. After discontinuation of sedation, tetraplegia was noted due to spinal cord ischemia from C3 to C7.

Frozen elephant trunk with Frozenix prosthesis

This paper presents the clinical applications of the Japanese-made frozen elephant trunk (FET, Frozenix®). The historical aspects of FET development, manufacture and structure of Frozenix, video images of a representative case, and a summary of a multi-centre Japanese Frozenix study, J-ORCHESTRA, are discussed.

Techniques and outcomes of total aortic arch repair with frozen elephant trunk for DeBakey I dissections

Total aortic arch replacement (TAR) with frozen elephant trunk (FET) technique (FET) has been increasingly used to treat a variety of aortic pathologies over the past two decades. Because FET can effectively treat the diseased arch and cover the proximal entry tear in the distal arch, it is a valuable option in the treatment of DeBakey I aortic dissections. This report focuses on the techniques and outcomes of TAR with FET for acute/chronic aortic dissection. A review of pooled literature including 27 observational studies showed in-hospital mortality, permanent stroke, and spinal cord injury rates of 8.4%, 5.9% and 2.6% for acute aortic dissections, and 7.5%, 4.0% and 4.6% for chronic aortic dissections, respectively. In most of the studies, complete false lumen thrombosis rate was achieved in 80% of patients at the level of FET for acute and chronic aortic dissections. Mid-term outcomes are equally promising. For chronic aortic dissections, positive remodeling of the non-stented distal aortic segments is less frequent leading to secondary reinterventions within 3 to 5 years. However, most studies have not applied distal abdominal extensions of the repair using fenestrated and branched endografts. In the current endovascular era, TAR + FET should be considered as an alternative to conventional open surgical repair in centers of excellence.

Repeat Surgery in Chronic Aortic Dissection: A New Technique without Touching the Native Aorta

BACKGROUND

 Repeat surgery of the chronically dissected aorta following repair of a Type-A acute aortic dissection (AAD) still represents a challenge. The proposed surgical options are as follows: (1) staged procedure with elephant trunk (ET) technique, (2) traditional frozen elephant trunk (FET) intervention, and (3) beating heart cerebral vessel debranching followed by thoracic endovascular aortic repair (TEVAR). However, a marked enlargement of the proximal descending thoracic aorta might make it difficult to perform FET/ET intervention. Furthermore, because in conventional surgery for AAD, a prosthetic graft replacement is generally limited to the ascending aorta, and in repeat surgery, this short Dacron graft rarely provides enough room to allow a beating heart cerebral vessel debranching and obtaining a reliable landing zone for the implantation of a firmly anchored stent graft.

METHODS

 We retrospectively reviewed all the five consecutive patients treated in our institution, between 2014 and 2017, for chronic aortic dissection after successful surgical treatment of acute Type-A aortic dissection with graft replacement limited to the ascending aorta. The five patients underwent repair utilizing a modified FET technique with total aortic arch and upper descending aorta exclusion without touching the native dissected aorta.

RESULTS

 No early- or midterm mortality was observed. Mean time interval between the initial and the reoperative procedure was 26 months (range, 3-80 months). No patient had a minor/major neurologic event. Mean circulatory arrest time was 16 minutes (range, 11-25 minutes). Mean follow-up time was 22 months (range, 9-42 months).

CONCLUSIONS

 We report our initial experience with a modified FET technique realized by anastomosing the stent graft with the previously implanted ascending aortic graft in Hishimaru's zone 0 and by rerouting all cerebral vessels without "touching" the native chronically dissected aorta. A larger number of patients and a longer follow-up will be required to confirm these initial encouraging results.

Spinal ischaemia after thoracic endovascular aortic repair with left subclavian artery sacrifice: is there a critical stent graft length?

OBJECTIVES

Thoracic endovascular aortic repair (TEVAR) is used for treatment of thoracic aortic pathologies, but the covered stent graft can induce spinal ischaemia depending on the length used. The left subclavian artery contributes to spinal cord collateralization and is frequently occluded by the stent graft. Our objective was to investigate the impact of covered stent graft length on the risk of spinal ischaemia in the setting of left subclavian artery sacrifice.

METHODS

Twenty-six pigs (German country race, mean body weight 36 ± 4 kg) underwent simulated descending aortic TEVAR via left lateral thoracotomy, with left subclavian artery and thoracic segmental artery occlusion in normothermia. Animals were assigned to treatment groups according to simulated stent graft length: TEVAR to T8 (n = 4), TEVAR to T9 (n = 4), TEVAR to T10 (n = 4), TEVAR to T11 (n = 7) and TEVAR to T12 (n = 1) and a sham group (n = 6). End points included spinal cord perfusion pressure, cerebrospinal fluid pressure and spinal cord blood flow using fluorescent microspheres.

RESULTS

There were no group differences in spinal cord perfusion pressure drop or in spinal cord perfusion pressure regeneration potential at 3 h after the procedure: from a baseline average of 75 mmHg (95% confidence interval 71-83 mmHg) to 73 mmHg (67-75 mmHg) at 3 h in Group T10 versus from a baseline average of 67 mmHg (95% CI 50-81 mmHg) to 65 mmHg (95% confidence interval 48-81 mmHg) in Group T8. There were no differences in the spinal cord blood flow courses over time in the different groups nor was there any difference in cerebrospinal fluid pressure levels and cerebrospinal fluid pressure dynamics between groups. However, we did observe local blood flow distribution to the spinal cord that was inhomogeneous depending on the distance between the simulated stent graft end and the first thoracic anterior radiculomedullary artery.

CONCLUSIONS

The risk of spinal ischaemia after serial segmental artery occlusion does not depend on the distal extent of the aortic repair alone. Future attempts to allow patient risk stratification for spinal ischaemia need to focus on anterior radiculomedullary artery anatomy together with the extent of planned aortic repair.

Risk factors for spinal cord injury in patients undergoing frozen elephant trunk technique for acute aortic dissection

BACKGROUND

The purpose of this study was to evaluate the risk factors for spinal cord injury (SCI) in patients with acute aortic dissection undergoing surgery with frozen elephant trunk technique (FET).

METHODS

From December 2014 to February 2018, 17 patients with acute aortic dissection underwent surgical treatment of the aortic arch with FET. SCI occurred in 3 patients. Risk factors for SCI were evaluated.

RESULTS

Mean age of the patients was 56 years and 88.2% were male. The ratio of true lumen to total aortic diameter at the level of carina (before: 0.48 vs. after: 0.75, P < 0.001), aortic valve (before: 0.47 vs. after: 0.67, P = 0.001), and celiac artery (before: 0.48 vs. after: 0.68, P = 0.003) increased after surgery. There were no significant differences in perioperative minimum hemoglobin level and postoperative mean arterial pressure between patients with and without SCI. However, patients with SCI had higher creatinine level before surgery (SCI: 1.32 mg/dL vs. no SCI: 0.81 mg/dL, P = 0.023). Although there was no difference in number of patent intercostal arteries before surgery, those originating from the true lumen were fewer in patients with SCI (SCI: 2.7 vs. no SCI: 8.6, P = 0.021). Furthermore, with entry closure, significant decrease in patency was observed in intercostal arteries originating from the false lumen (before: 3.1 vs. after: 1.0, P < 0.001).

CONCLUSION

FET was useful in entry closure. However, FET in patients with higher creatinine level and those who may have significant spinal cord perfusion from the false lumen could be a risk factor for postoperative SCI.