Frozen elephant trunk technique and partial remodeling for acute type A aortic dissection

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.

Volume Changes in the Descending Aorta after Frozen Elephant Trunk and Conventional Hemi-Arch Repair after Acute Type A Aortic Dissection

The aim of this study was to compare the mortality rates, re-intervention rates, and volumetric changes in aortas following surgery, in terms of the true lumen and false lumen changes, using conventional hemi-arch repair (CET) and frozen elephant trunk (FET) techniques. During the period from 2015 to 2018, 66 patients underwent surgical treatment for acute aortic dissection (Debakey type 1). Demographic and procedure-related data were evaluated. We measured volumetric change before surgical treatment, at discharge, and at 12- and 24-month time points based on computed tomography angiography. The study cohort was divided into two groups (FET vs. CET). The mean age of the patients was 56.9 ± 9.4 years in the FET group versus 63.6 ± 11 years in the CET group (p = 0.063). The mean follow-up time was 24 ± 6 and 25 ± 5 months for the FET and CET groups, respectively. There were no significant differences between the two groups in terms of the medical histories of the cohorts. The results showed a significant increase in true lumen volume after the FET procedure (within 24 months postoperatively; p = 0.005), and no significant changes in total (p = 0.392) or false lumen (p = 0.659) volumes were noted. After the CET procedure, there were significant increases in total and false lumen volumes (p = 0.013, p = 0.042), while no significant change in true lumen was observed (p = 0.219). The volume increase in true lumen after the FET procedure was higher compared to the CET group at all postoperative time points (at discharge, 12 months, and 24 months) without significant evidence (p = 0.416, p = 0.422, p = 0.268). At two years, the volume increase in false lumen was significantly higher among the CET group compared to the FET group (p = 0.02). The Kaplan–Meier curve analysis showed that patients who underwent the CET procedure underwent significantly more re-interventions due to false lumen expansion of the descending aorta (p = 0.047). Present study results indicate that the true and false lumen changes in the aorta following the FET and CET procedures were different. FET led to a significant increase in true lumen volume, while false lumen volume remained stable; however, after the CET procedure, significant false lumen enlargement was noted at mid-term follow-up time points. The re-intervention rate after CET was higher due to false lumen expansion.

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.

Anterolateral Partial Sternotomy for Treatment of Graft Infection with Fungal Vegetation on the Frozen Elephant Trunk: A Case Report

A 49-year-old man, who had undergone total arch replacement (TAR) with frozen elephant trunk (FET) technique for type A acute aortic dissection, was subsequently transferred to our hospital for uncontrollable infection. Since multiple blood cultures were positive for Candida parapsilosis and transesophageal echocardiography revealed vegetation attached to the FET, he was diagnosed with a graft infection. In addition, on the 18-fluorodeoxyglucose positron emission tomography scans, high uptake lesions were found around the quadrifurcated graft as well as the FET. Therefore, an extensive TAR through anterolateral thoracotomy with partial sternotomy was performed to remove all infected prothesis. Consequently, the patient completely recovered.

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.

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.

Open total arch replacement with trifurcated graft and frozen elephant trunk

Background

The frozen elephant trunk (FET) technique was introduced in Hannover Medical School in 2001 to treat patients with complex aortic arch pathologies. Since 2012, we primarily use the trifurcated Thoraflex Hybrid FET graft. In this article, we report our experience with the trifurcated FET graft.

Methods

Between November 2012 and September 2018, 211 patients underwent FET implantation with the trifurcated Vascutek Thoraflex Hybrid graft. The indications for surgery were: degenerative aneurysms in 68 patients, acute aortic dissections (AD) in 96 patients, and chronic ADs in 47 patients. And, 18% of cases were sternal re-operations.

Results

Mean cardiopulmonary bypass time, aortic cross-clamp time, and myocardial ischemia time were 262±84, 115±71, 50±26 minutes, respectively. Incidence of re-thoracotomy for bleeding, stroke, permanent paraplegia/paraparesis, prolonged ventilatory support (>96 h), and long-term dialysis were 13%, 18%, 2%, 21%, and 5%, respectively. In-hospital mortality was 12%. Follow-up was complete for 100% of patients and comprised a total of 513 patient years. The mean follow-up time was 2.2 [0-6] years. During follow-up, there were 32 aortic re-interventions distal to the FET. The survival rate at 1 and 5 years was 84% and 81%, respectively.

Conclusions

Total aortic arch replacements with trifurcated FET can be performed with positive results. The trifurcated graft allows selective anastomosis of the supra-aortic vessels, which might result in improved hemostasis.

Aortic remodeling in acute type A aortic dissection after frozen elephant trunk implantation

Survivors at first intervention after acute type A aortic dissection often necessitate additional interventions to avoid dilation and rupture of the remaining thoraco-abdominal aorta. During the first-stage arch procedure, the attempt to treat the descending thoracic aorta with a stent graft could attenuate this phenomenon and reduce the need for further open or endovascular reinterventions. In this short review article, the frozen elephant trunk technique was tested as influencing factor of aortic remodeling during follow-up analysis. Late results from the identified studies suggested promising rates of false lumen thrombosis of the descending thoracic aorta (78-100%), suggesting that aortic remodeling is highly probable with this approach. However, a longer surveillance of the aortic diameters is still necessary to confirm this initial hypothesis.

The frozen elephant trunk surgery: a systematic review analysis

The frozen elephant trunk might be considered one of the most appreciated innovations during the last decades to treat complex thoracic aortic lesions. Many useful tips have been progressively introduced to standardize the procedures and, nowadays, the improved post-operative outcomes contributed to spread the procedure. The following article will provide a comprehensive review analysis of the Frozen Elephant Trunk (FET) technique, throughout the current available devices, possible surgical indications and primary post-operative complications.

Early and mid-term results of frozen elephant trunk procedure for acute type A aortic dissection

BACKGROUND

This study aims to investigate the early and mid-term results of total thoracic aorta repair with E-vita OPEN PLUS stent graft, which we used to remove the residual false lumen and prevent late-term complications in patients with acute type A aortic dissections.

METHODS

The study included 41 patients (29 males, 12 females; mean age 51.9±10.4 years; range, 30 to 77 years) who underwent total thoracic aorta repair with frozen elephant trunk stent graft for acute type A aortic dissection between November 2013 and November 2017. The reduction in false lumen size and thrombosis were evaluated by repeated computed tomographyangiography on 10th day and third, sixth, and 12th months.

RESULTS

Six patients (14.6%) were lost during hospital stay and one patient (2.4%) was lost during the follow-up period. Frozen elephant trunk stent graft"s distal end at descending aorta ended at T6, T7, and T8 levels in 15 (36.6%), 21 (51.2%), and five (12.2%) patients, respectively. The supra-aortic vessels were re-implanted separately in 21 (51.2%) or as island in 20 (48.8%) patients. Transient paraparesis (spinal cord ischemia) was observed in only one patient (2.4%), while permanent neurologic deficit (stroke or coma) was observed in two patients (4.9%). Mean duration of follow-up was 26.5±20.5 months. Computed tomography-angiography at first month showed that false lumen became thrombosed at rates of 93.9% and 54.5% at pulmonary trunk and diaphragmatic level, respectively.

CONCLUSION

We believe that total arcus repair in acute type A aortic dissection treatment with single-session frozen elephant trunk technique by ensuring early false lumen thrombosis is safe and successful.

Surgical outcomes of acute type A aortic dissection in dialysis patients

BACKGROUND

Acute type A aortic dissection (ATAAD) is relatively uncommon in dialysis patients, and characteristics and repair outcomes are not fully understood.

PATIENTS AND METHODS

Patients with ATAAD (n = 960) were divided into a dialysis group (n = 19) and non-dialysis group (n = 941), depending on whether they required dialysis for preoperative end-stage renal disease (ESRD). Hospital charts and imaging data were reviewed, and characteristics and outcomes were compared between the groups. Segmental aortic wall or intima/media flap calcification in the thoracic and abdominal aorta was assessed in the dialysis patients.

RESULTS

The leading primary causes of ESRD were polycystic kidney disease (n = 5) and chronic glomerulonephritis (n = 5). There were no significant differences (dialysis group vs. non-dialysis group) in age (60.5 vs. 64.5 years), preoperative hemodynamics, or organ ischemia. Dialysis patients were more likely to have an entry tear in the aortic arch (42% vs. 15%, p = 0.003). These patients showed moderate-to-severe calcification (multiple focal or single focal calcification > 10 mm) in the ascending aorta (17%), aortic arch (61%), descending aorta (67%), and abdominal aorta (83%). Arch replacement was common in this group (37% vs. 18%, p = 0.030). Although in-hospital mortality was increased in this group (21% vs. 7%, p = 0.059), morbidities did not differ significantly. Six-year survival was 60.3 ± 13.4% and 78.8 ± 1.6%, respectively (p = 0.01).

CONCLUSIONS

Dialysis patients tend to have aortic calcification and a primary tear in the aortic arch. Outcomes are acceptable.

Intimal re-layering technique for type A acute aortic dissection-reconstructing the intimal layer continuity to induce remodeling of the false channel

Background

Residual false channel is common after repair of type A acute aortic dissection (TAAAD). Starting from our recent series of TAAAD patients we carried out a retrospective analysis, regarding the failure of primary exclusion at the time of the initial operation. We classified the location of the principal entry tears perfusing the residual false channel. The proposed technique represents our attempt to correct the mechanism of false channel perfusion during primary repair. We describe a new technique designed to address some limitations of standard hemiarch aortic replacement. Its goal are: (I) to reinforce the intimal layer at the arch level; (II) to eliminate inter-luminal communications at the arch level using suture lines around the arch vessels; (III) to provide an elephant trunk configuration for further interventions.

Methods

Between August 2016 and January 2018, 11 patients underwent emergency surgery using this technique; 7 were men; the median age was 74 years. All patients were treated using systemic circulatory arrest under moderate hypothermia (26 °C) and selective cerebral perfusion. All patients had supra-coronary repair; 1 patient had aortic valve replacement + CABG. In the first two patients a manual suture around supra-aortic trunks was used; the subsequent seven patients were treated with a mechanical suture bladeless device. CT scan follow up was performed in all survivors with controls before discharge 3 months and 1 year after operation.

Results

No patient died in the operating room and no neurologic deficit was observed in this initial experience. One patient died in POD 5th for low cardiac output syndrome. Median ICU stay was 3 days (IQR, 2-6 days). Hospital mean length of stay was 15.2±8 days. Median cardiopulmonary bypass time was 130 min (IQR, 110-141 min); median arrest time for re-layering was 17 min (IQR, 16-20 min); median total arrest was 36 min (IQR, 29-39 min). Distal aortic anastomosis was performed in zone 0 in 4 patients, zone 1, with innominate replacement, in 5 patients, in zone 2, with branches to innominate and left common carotid arteries, in 2 patients. Median follow up (closing date 06/01/2018) was 443 days (IQR, 262-557 days); no late deaths occurred. No dehiscence at the level of stapler or manual sutures was observed. Proximal 1/3 of the thoracic aorta false channel was obliterated in all cases but one; in 3 cases complete exclusion of the false channel was obtained after operation. In one case stent graft completion was required.

Conclusions

This technique combines the advantages of arch replacement to the simplicity of anterior hemiarch repair. This study demonstrates the safety of the procedure and the possibility to induce aortic remodeling without complex arch replacement.

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.

Hemiarch versus total aortic arch replacement in acute type A dissection: a systematic review and meta-analysis

BACKGROUND

Despite recent advances in aortic surgery, acute type A aortic dissection remains a surgical emergency associated with high mortality and morbidity. Appropriate management is crucial to achieve satisfactory outcomes but the optimal surgical approach is controversial. The present systematic review and meta-analysis sought to access cumulative data from comparative studies between hemiarch and total aortic arch replacement in patients with acute type A aortic dissection.

METHODS

A systematic review of the literature using six databases. Eligible studies include comparative studies on hemiarch versus total arch replacement reporting short, medium and long term outcomes. A meta-analysis was performed on eligible studies reporting outcome of interest to quantify the effects of hemiarch replacement on mortality and morbidity risk compared to total arch replacement.

RESULT

Fourteen retrospective studies met the inclusion criteria and 2,221 patients were included in the final analysis. Pooled analysis showed that hemiarch replacement was associated with a lower risk of post-operative renal dialysis [risk ratio (RR) =0.72; 95% confidence interval (CI): 0.56-0.94; P=0.02; I(2)=0%]. There was no significant difference in terms of in-hospital mortality between the two groups (RR =0.84; 95% CI: 0.65-1.09; P=0.20; I(2)=0%). Cardiopulmonary bypass, aortic cross clamp and circulatory arrest times were significantly longer in total arch replacement. During follow up, no significant difference was reported from current studies between the two operative approaches in terms of aortic re-intervention and freedom from aortic reoperation.

CONCLUSIONS

Within the context of publication bias by high volume aortic centres and non-randomized data sets, there was no difference in mortality outcomes between the two groups. This analysis serves to demonstrate that for those centers doing sufficient total aortic arch activity to allow for publication, excellent and equivalent outcomes are achievable. Conclusions on differences in longer term outcome data are required. We do not, however, advocate total arch as a primary approach by all centers and surgeons irrespective of patient characteristics, but rather, a tailored approach based on surgeon and center experience and patient presentation.

Open Stented Grafts for Frozen Elephant Trunk Technique: Technical Aspects and Current Outcomes

With growing experience in patients with aneurysms and dissections in the arch and proximal descending aorta, the frozen elephant trunk (FET) technique has been shown to be safe and effective, and has achieved favorable short to mid-term outcomes. As the FET technique is gaining wider acceptance, there is a growing need for versatile, technically simple, and highly durable open stented grafts involving less complicated deployment mechanisms enabling use in various indications. This paper gives a brief review on the technical aspects and clinical outcomes of currently available open stented grafts used in the FET technique, including the E-vita Open Plus, Thoraflex Hybrid, Cronus, and J Graft. While none of these grafts can claim to be an ideal device, technology continues to improve towards this goal. As newer devices and systems are developed, more widespread use of the FET technique can be expected; such progress promises to improve the clinical outcomes and quality of life for patients with complex aortic diseases.

Outcome of frozen elephant trunk technique for acute type A aortic dissection: as systematic review and meta-analysis

Acute aortic dissections of Stanford type A require emergency surgery repair and present challenges to surgeons. The frozen elephant technique is one of several approaches used to treat aortic arch dissection. The purpose of this meta-analysis was to investigate the clinical effectiveness of the frozen elephant technique for treating acute type A aortic dissection.Medline, Cochrane, Google Scholar, and ClinicalTrials.gov databases were searched up to March 31, 2014, for studies that assessed the use of frozen elephant trunk technique for treating acute type A aortic dissection. The primary outcome was in-hospital mortality. Secondary outcomes included rate of stroke, spinal cord injury, renal failure, and reoperations for bleeding.Eleven studies were included in the analysis that encompassed 881 patients. The mean age ranged from 45.4 to 66.8 years, and the proportion of the population that was male ranged from 45 to 85%. The overall in-hospital mortality rate was 8%. The rate of stroke, spinal cord injury, renal failure, and frequency of reoperations for bleeding were 3, 4, 5, and 5, respectively. Sensitivity analysis indicates that the findings are robust and there was no publication bias.These findings indicate that the frozen elephant techniques does not bring unacceptable mortality or morbidity risk for treating acute type A aortic dissection.

Clinical significance of a false lumen pathway through the arch in acute type A aortic dissection and its influence on cervical branch compromise

OBJECTIVES

Upon onset of acute type A aortic dissection, the aortic true lumen generally becomes fixed around the supra-aortic branches in the greater curvature and Botallo's ligament in the lesser curvature of the aortic arch. Therefore, the pathways of the false lumen through the arch can be categorized as anterior, bilateral and posterior. We investigated the relationship between a false lumen pathway through the arch and cervical branch compromise, stratified by primary tear location.

METHODS

Sixty-four consecutive patients with acute type A aortic dissection underwent emergency surgery at our institution between March 2005 and October 2013. Of these, 40 cases (63%) were DeBakey type I, 15 cases (23%) were type II and 9 cases (14%) were type III-D (retrograde type A). We conducted a retrospective review of preoperative computed tomographic angiography using three-dimensional image post-processing tools for 43 cases, excluding 15 cases with type II and 6 cases with type I for which preoperative digital image data were not available.

RESULTS

Of the 43 cases, 14, 18 and 11 revealed anterior, bilateral and posterior pathways, respectively. Twenty-one cases (49%) showed a primary intimal tear in the ascending aorta (8 anterior, 12 bilateral and 1 posterior), 12 cases (28%) showed a primary intimal tear in the aortic arch (5 anterior, 3 bilateral and 4 posterior) and 10 cases (23%) showed a primary intimal tear in the descending aorta (1 anterior, 3 bilateral and 6 posterior). Twelve of the 14 anterior pathway cases (86%) had a total of 26 supra-aortic branch compromises, 13 of the 18 bilateral pathway cases (72%) had a total of 20 supra-aortic branch compromises, while only 4 of the 11 posterior pathway cases (36%) had a total of four supra-aortic branch compromises. None of the 11 posterior pathway cases had a dissection extending into all 3 supra-aortic branches.

CONCLUSIONS

Posterior pathway cases generally showed primary tear locations in the arch or descending aorta, and cervical branch compromise was rare. Aortic dissections tended to extend into the cervical branches through the anterior side of the aortic arch. A false lumen pathway through the arch was strongly associated with cervical branch compromise in acute type A aortic dissections.

Clinical outcomes of combined aortic root reimplantation technique and total arch replacement

OBJECTIVES

The goal of this study was to evaluate early and late outcomes of combined valve-sparing aortic root replacement and total arch replacement (TAR).

METHODS

From October 1999 to May 2014, 195 patients underwent valve-sparing operations using the David reimplantation technique. Thirty-one patients underwent combined TAR for aortic regurgitation (AR) with extended aortic aneurysm from the aortic root to the aortic arch. Aetiologies included acute type A aortic dissection in 12 cases, chronic aortic dissection in 8 cases and non-dissecting aneurysm in 11 cases. There were 9 patients with Marfan syndrome. The preoperative severity of AR was mild in 4, moderate in 16 and severe in 11. Even though half of those were emergent operations for acute aortic dissection, preoperative haemodynamic conditions were stable in all patients.

RESULTS

No hospital deaths occurred. Postoperative complications included prolonged mechanical ventilation (>48 h) in 1 case and re-exploration for bleeding in 2 cases. Other complications, such as neurological dysfunction or low cardiac output syndrome, were not observed. At hospital discharge, 2 patients had mild AR, 22 had trace AR and 7 had no AR. During follow-up, 2 patients had moderate AR, 7 had mild AR, 18 had trace AR and 3 had no AR. Follow-up was completed in 95.1% of patients, and the mean follow-up period was 60.5 ± 9.1 months. No late death and thromboembolic complication occurred during follow-up. One patient required reoperation for AR. Freedom from reoperation at 5 and 10 years was 100 ± 0 and 83.3 ± 3.5%, respectively. Freedom from moderate or severe AR at 3 and 5 years was 83.3 ± 3.5 and 83.3 ± 3.5%, respectively.

CONCLUSIONS

Early outcomes of combined aortic root reimplantation and TAR were satisfactory and provided excellent freedom from thromboembolic complication. The rate of freedom from reoperation during long-term follow-up was acceptable. Further follow-up is required to evaluate this procedure.

Frozen elephant trunk surgery-the Bologna's experience

BACKGROUND

Different approaches are available to treat patients with complex and extensive diseases of the thoracic aorta. This study aims to report and comment on our experience with the frozen elephant trunk (FET) technique.

METHODS

Between January 2007 and July 2012, 122 patients (male: 86.9%; mean age: 61 years) underwent extensive thoracic aorta surgery using the FET approach with an E-vita open prosthesis. The most frequent indications for surgery included residual type A chronic dissection (45.9%), extensive degenerative aneurysm of the thoracic aorta (27%), and type A acute aortic dissection (7.4%). Sixty-nine patients had already undergone cardiac/aortic interventions through a median sternotomy. A total of 60 associated procedures were performed, with 76.6% on the aortic root. Selective antegrade cerebral perfusion and moderate hypothermia were used in all cases.

RESULTS

Overall, hospital mortality was 15.2%. Post-operatively, 7.4% and 9.0% of patients were complicated by permanent neurologic dysfunction and spinal cord injury, respectively. For the surviving patients, 1- and 3-year freedom from all-cause mortality was (91.7±2.8)% and (79.1±6.1)%, respectively. 1- and 3-year freedom from re-intervention was (83.1±3.5)% and (74.1±4.3)%, respectively.

CONCLUSIONS

In our experience, FET surgery allowed treatment of complex patients with extensive thoracic aortic diseases with satisfactory short- and mid-term results. Acute and chronic dissections represent interesting subsets for FET application. While further larger and longer-term studies are required to show the survival benefits of the FET technique versus other types of management, new strategies for spinal cord injury (paraplegia/paraparesis) reduction should also be researched.

Safety and pitfalls in frozen elephant trunk implantation

The frozen elephant trunk (FET) procedure, or open stent grafting, is a tool for the combined open and endovascular treatment via a median sternotomy of extensive aortic disease involving both aortic arch and descending thoracic aorta. The technique aims to stabilize the maximum extent of the thoracic aorta in one step, with the goal of either rendering a secondary intervention to the downstream aorta unnecessary or producing an easy landing zone for secondary thoracic endovascular aortic repair (TEVAR) or open surgery. Even though large case series have reported good results, we still have no conclusive evidence as to which patients and what kind of pathologies benefit from this technique. The surgical sequences described for total arch replacement with the FET procedure are just as varied as the associated devices and indications. This article focuses on important perioperative and surgical aspects, as well as potential complications during FET procedures.

Sun's procedure of total arch replacement using a tetrafurcated graft with stented elephant trunk implantation: analysis of early outcome in 398 patients with acute type A aortic dissection

BACKGROUND

Acute type A aortic dissection (AAAD) remains one of the most lethal conditions requiring surgical repair, and is associated with a high rate of postoperative mortality and morbidity. Despite the satisfactory clinical outcomes achieved with the frozen elephant trunk technique so far, controversies still exist regarding the use of this aggressive approach in patients with AAAD. In this study, we seek to analyze the early outcomes of the Sun's procedure, which is an approach integrating total arch replacement using a 4-branched graft with implantation of a special stented graft in the descending aorta, and identify the risk factors for postoperative mortality and morbidity of the Sun's procedure in patients with AAAD.

METHODS

Clinical data of 398 consecutive AAAD patients undergoing the Sun's procedure were analyzed. The associations between 20 preoperative and intraoperative variables and early mortality were assessed by univariate and multivariate analysis.

RESULTS

Early mortality occurred in 31 patients (7.8%, 31/398), with leading causes including multi-organ failure in 16 patients (51.6%), permanent neurologic deficit in 6 (19.4%), and low cardiac output syndrome in 4 (12.9%). Permanent neurologic deficit and spinal cord injury occurred, each in 10 patients (2.5%, 10/398). Five significant risk factors for early mortality were identified with multivariate analysis: preexisting cerebrovascular disease [relative risk (RR) 14.76; P<0.001], acute heart failure (RR 18.18; P=0.001), spinal cord malperfusion (RR 60.13; P<0.002), visceral malperfusion (RR 30.25; P<0.001) and cardiopulmonary bypass time >190 minutes (RR 3.62; P=0.007).

CONCLUSIONS

The Sun's procedure has generated a relatively lower mortality rate in 398 patients with AAAD. Patients with preexisting cerebrovascular disease, acute heart failure, spinal cord malperfusion, visceral malperfusion and long cardiopulmonary bypass time are at a higher risk of early mortality.

A systematic review and meta-analysis of hybrid aortic arch replacement

BACKGROUND

Evolution in the endovascular era has influenced the management of aortic arch pathologies. Several studies have described the use of a combined endovascular and open surgical approach to the treatment of arch diseases. Hybrid repair of arch pathologies has been considered as a less invasive method, and is therefore an appealing option for high-risk patients who are unsuitable for open repairs. The aim of the present meta-analysis was to assess the efficacy of hybrid techniques in patients with aortic arch pathologies.

METHODS

Extensive electronic literature search was undertaken to identify all articles published up to December 2012 that described hybrid aortic arch repair with intrathoracic supra-aortic branch revascularisation and subsequent stent graft deployment. Eligible studies were divided into two groups: group I included studies on the aortic arch debranching procedure and group II included studies that reported an elephant trunk technique (either "frozen" or stented). Separate meta-analyses were conducted in order to assess technical success, stroke, spinal cord ischemia (SCI), renal failure requiring dialysis, and cardiac and pulmonary complications rate, as well as 30-day/in-hospital mortality.

RESULTS

Forty-six studies were eligible for the present meta-analysis: 26 studies with a total of 956 patients reported aortic arch debranching procedures, and 20 studies with 1,316 patients performed either 'frozen' or stented elephant trunk technique. The pooled estimate for 30-day/in-hospital mortality was 11.9% for the arch debranching group and 9.5% for the elephant trunk group. Cerebrovascular events of any severity were found to have occurred postoperatively at a pooled rate of 7.6% and 6.2%, while irreversible spinal cord injury symptoms were present in a pooled estimate of 3.6% and 5.0% in the arch debranching and elephant trunk group, respectively. Renal failure requiring dialysis occurred at 5.7% and 3.8% in both groups, while cardiac complications rate was 6.0% in the arch debranching cohort and pulmonary complication was 19.7% in the elephant trunk cohort.

CONCLUSIONS

Hybrid arch techniques provide a safe alternative to open repair with acceptable short- and mid-term results. However, stroke and mortality rates remain noteworthy. Future prospective trials that compare open conventional techniques with the hybrid method or the entirely endovascular methods are needed.

Open stent grafting for complex diseases of the thoracic aorta: clinical utility

Open stent grafting is an alternative treatment for extensive thoracic aortic replacement. However, this procedure is associated with a high incidence of spinal cord injury, which has limited its application. Multiple factors have been suggested to explain the risk of spinal cord injury, including deep delivery of the stent graft, history of operation of the downstream aorta, and postoperative low blood pressure. Cerebrospinal fluid drainage or a hybrid operation in combination with trans-femoral thoracic stent grafting is useful for preventing spinal cord injury. Open stent grafting remains an alternative treatment for atherosclerotic aneurysms with dilatation of the ascending aorta. Open stent grafting for acute aortic dissection is effective for remodeling of the false lumen. The graft diameter for aortic dissection should be 90 % of the total diameter of the aorta, and the distal landing zone should be limited to the T7 vertebral level to prevent new intimal tears or spinal cord injury. Open stent grafting seems a feasible bailout strategy for the treatment of retrograde aortic dissection after TEVAR for type B aortic dissection. Newly designed devices for open stent grafts include the Matsui-Kitamura stent graft or branched open stent graft, which is produced in Japan. The effectiveness of open stent grafting in the treatment of Marfan syndrome remains unclear. A commercially available device for open stent grafting would be desired in Japan. In conclusion, an open stent graft remains an alternative treatment for complex thoracic aortic pathologies.

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.

What makes the difference between the natural course of a remaining type B dissection after type A repair and a primary type B aortic dissection?

OBJECTIVES

To analyse the outcome and need for intervention [surgery or thoracic endovascular aortic repair (TEVAR)] in patients after surgery for remaining type B dissection after type A repair and primary type B aortic dissection.

METHODS

Within a 10-year period, 247 patients with remaining type B after type A, and 112 patients with primary type B aortic dissection were analysed. We assessed the clinical outcome as well as the need for intervention (surgery or TEVAR) within the aortic arch and the thoracoabdominal aorta as well as risk factors.

RESULTS

The median follow-up was 23 months (interquartile range 5-52). There was a significant difference with regard to the status of the primary entry tear between patients after surgical repair of an acute type A aortic dissection and primary acute type B aortic dissection (patent vs. non-patent entry 35 vs. 83%, P < 0.001). The overall need for any kind of intervention (surgery or TEVAR) was 19%. Multivariate Cox regression analysis revealed a patent primary entry tear in patients after surgery for acute type A aortic dissection as an independent predictor for intervention (surgery or TEVAR) during follow-up [odds ratio (OR) 6.4; confidence interval (CI) 1.39-29.81, P = 0.017]. Multivariate Cox regression analysis did not reveal a patent primary entry tear in patients after acute type B aortic dissection as an independent predictor for intervention (surgery or TEVAR) during follow-up (OR 0.67; CI 0.27-1.69, P = 0.671). Finally, the thrombosis status of the false lumen was not an independent predictor for intervention (surgery or TEVAR) either in patients after surgery for acute type A aortic dissection (OR 3.46; CI 0.79-15.16, P = 0.100) or in patients after acute type B aortic dissection (OR 0.77; CI 0.31-1.93, P = 0.580).

CONCLUSIONS

A remaining type B dissection after type A repair and a primary type B aortic dissection represent two distinct pathophysiological entities with regard to late outcome. The need for any kind of intervention in the thoracoabdominal aorta is significantly higher in primary type B aortic dissections. A remaining patent primary entry tear independently predicts the need for intervention (surgery or TEVAR) in patients after surgery for acute type A aortic dissection and, thereby, remains the main target of initial therapy. The thrombosis status of the false lumen seems to be of secondary importance.