Systematic review of clinical outcomes in hybrid procedures for aortic arch dissections and other arch diseases

Challenges and experience of setting up an aortic service

Aortic surgery is a complex procedure posing high risks in comparison to other adult cardiac surgeries. Novel surgical approaches including minimally invasive procedures, sutureless aortic valve replacement, and transcatheter aortic valve implantation have been found to be acceptable alternatives to conventional surgeries. In addition, novel endovascular repair techniques and hybrid procedures have been introduced for the management of patients with thoracoabdominal aortic pathologies. However, these modalities are not readily available in every center, and such novel procedures impose a learning curve for surgeons and high costs for affected patients. In this review, we discuss the challenges of setting up an aortic service, having regard to the Iranian experience.

Thoracic aortic surgery: status and upcoming novelties

Several novel technological developments and surgical approaches have characterized the field of aortic surgery in the recent decade. The progressive introduction of endovascular procedures, minimally invasive surgical techniques and hybrid approaches have changed the practice in aortic surgery and generated new trends and questions. Also, the advancements in the manufacturing of tissue engineered vascular grafts as substitutes for aortic replacements are enlightening new avenues in the treatment of aortic disease. This review will provide an overview of the current novel perspectives, debates and trends in major thoracic aortic surgery.

Outcomes Of Chimney Technique For Aortic Arch Diseases: A Single-Center Experience With 226 Cases

Purpose

The goal of present study is to document our single-center experience with chimney technique for aortic arch diseases.

Patients and methods

From August 2012 to October 2017, 226 patients (mean age 54±12 years; 197 men) with aortic arch diseases underwent thoracic endovascular aortic repair combined with chimney stents. The aortic stent-grafts were deployed in zone 0 (n=22), zone 1 (n=13), or zone 2 (n=191).

Results

The technical success rate was 84% (189/226) and immediate type Ia endoleak (ELIa) happened in 37 (16%) patients. The 30-day mortality and morbidity rates were 2% (4/226) and 4% (8/226), respectively. Major adverse events include four major strokes, three spinal cord ischemia and one aortic rupture in the early-term. The clinical and imaging follow-up rates were 98% (218/222) and 78% (173/222), respectively. The average lengths of clinical and imaging follow-up were 22±16 months and 20±15 months, respectively. Chimney stent obstructions in left subclavian arteries were recorded in six (3%) patients. During follow-up, five patients died (2%) and two major strokes occurred (1%). One patient (0.5%) underwent reintervention.

Conclusion

The current study documented that the chimney technique is effective and safe for treating aortic arch diseases in different aortic zones. Cautions are needed to assess the permanency of chimney stent and to reduce the immediate ELIa rate.

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.

Is debranching thoracic endovascular aortic repair acceptable as the first choice for arch aneurysm in the elderly?

OBJECTIVES

This study aimed to assess differences in midterm outcomes between total arch replacement (TAR) and debranching thoracic endovascular aortic repair (d-TEVAR) and to evaluate the validity of d-TEVAR as the preferred treatment choice for aortic arch aneurysm in the elderly.

METHODS

We reviewed the case histories of 86 patients who had undergone TAR (64 men; mean age 78 ± 2.9 years) and 121 patients who had undergone d-TEVAR (90 men; mean age 82 ± 4.5 years) between 2007 and 2017; of these patients, 50 from each group were matched based on propensity scores to adjust for differences in patient characteristics.

RESULTS

Rates of freedom from all-cause mortality at 2 and 4 years were similar between the 2 groups (88% and 77% in the TAR group vs 82% and 64% in the d-TEVAR group, P = 0.11), but rates of freedom from reintervention at 2 and 4 years were significantly higher in the TAR group (100% and 96%) than in the d-TEVAR group (97% and 88%) (P = 0.004). Propensity score matching yielded similar survival rates of 88% and 85% for TAR vs 86% and 71% for d-TEVAR (P = 0.53) and comparable freedom from reintervention rates (100% and 97% in TAR, 98% and 90% in d-TEVAR, P = 0.16) at 2 and 4 years. Cox regression analysis identified previous cerebral infarction [hazard ratio (HR) 3.9; P = 0.005 in TAR/HR 3.1; P = 0.002 in d-TEVAR] as an independent positive predictor of overall mortality in both groups.

CONCLUSIONS

Midterm outcomes after TAR and d-TEVAR were satisfactory and propensity score matching-based evaluation revealed no significant differences in outcomes, implying that d-TEVAR is an acceptable first-choice procedure for aortic arch aneurysm in patients older than 75 years.

FEATURES OF DEBRANCHING TECHNIQUE FOR AORTIC DISSECTIONS AND ANEURYSMS IN THORATIC AND THORACO-ABDOMINAL AORTAS

This article describes a hybrid surgical technique for high-risk patients with thoraco-abdominal aortic dissections and aneurysms. The technical aspects of the first stage of surgical treatment - visceral and brachiocephalic debranching are described in detail. 17 surgical interventions for chronic dissection and aneurysm in the thoracic and thoracoabdominal aortas were performed at the Vishnevsky National Medical Research Center of Surgery of Ministry of Health of the Russian Federation in the period from 2014 to 2019. In two cases, we observed postoperative pancreatitis after surgical treatment of the abdominal aorta branches, which we managed using conservative therapy. After open surgery, all patients were discharged in a satisfactory condition. The selected technique made it possible to prepare patients for the following stage of treatment - endografting of the aorta - without developing serious complications.

Open aortic arch surgery: the gold standard method

Aortic arch pathologies are complex and treating them requires close team collaboration and technical skills to provide safe outcomes with low morbidity and mortality rates. Such challenges are facing both aortic and vascular surgeons. Open aortic arch repair has been the standard method of practice in all cases of aortic arch pathologies for the last four decades since the very first successful published case series by Griepp et al. during 1975. However, since then, repair of multi-segmented thoracic aortic pathologies has been explored through endovascular techniques; this is with or without open repair as a one-stage procedure especially in high-risk and elderly patients. Although the role of endovascular techniques in thoracoabdominal aorta is well established, its utilization as solo technique in aortic arch pathologies remains debatable. In this review, we highlight current evidences behind using open, endovascular, and hybrid procedures in aortic arch surgery.

The current role of echocardiography in acute aortic syndrome

Acute aortic syndrome (AAS) comprises a range of interrelated conditions caused by disruption of the medial layer of the aortic wall, including aortic dissection, intramural haematoma and penetrating aortic ulcer. Since mortality from AAS is high, a prompt and accurate diagnosis using imaging techniques is paramount. Both transthoracic (TTE) and transoesophageal echocardiography (TEE) are useful in the diagnosis of AAS. TTE should be the first imaging technique to evaluate patients with thoracic pain in the emergency room. Should AAS be suspected, contrast administration is recommended when images are not definitive. TEE allows high-quality images in thoracic aorta. The main drawback of this technique is that it is semi-invasive and the presence of a blind area that limits visualisation of the distal ascending aorta near. TEE identifies the location and size of the entry tear, secondary communications, true lumen compression and the dynamic flow pattern of false lumen. Although computed tomography (CT) is the most used imaging technique in the diagnosis of AAS, echocardiography offers complementary information relevant for its management. The best imaging strategy for appropriately diagnosing and assessing AAS is to combine CT, mainly ECG-gated contrast-enhanced CT, and TTE. Currently, TEE tends to be carried out in the operating theatre immediately before surgical or endovascular therapy and in monitoring their results. The aims of this review are to establish the current role of echocardiography in the diagnosis and management of AAS based on its advantages and limitations.

Aortic arch aneurysms and dissection-open repair is the gold standard

The aortic arch repair is one of the most complex surgeries and carries a high risk of complications as well as mortality. Since 1975, when the arch repair was first done by Randall B. Griepp using hypothermic circulatory arrest, many new technologies were introduced. But even with the use of antegrade and retrograde perfusion techniques and improvement of surgical techniques and grafts, the rate of mortality, cerebral, spinal, and visceral damage was much higher as compared to any other cardiac surgeries. With further developments aimed at less invasive approaches, thoracic endovascular aortic repair (TEVAR) along with de-branching of supra-aortic vessels or the frozen elephant trunk was introduced. Here, in this article, we review the myriad of approaches to the aortic arch and have come to a conclusion that while traditional open surgery is considered as the gold standard for treatment of extensive aortic arch pathologies, one school of thought suggests hybrid techniques such as the frozen elephant trunk and aortic arch vessel de-branching as more appropriate procedures for high-risk patients, where co-morbidities may contraindicate cardiopulmonary bypass and longer operative times required for traditional repair. No randomized trials are present to compare between open and hybrid or endovascular procedure in normal or high-risk patients. The meta-analysis of most of the studies defines open surgery as the gold standard for arch pathology because the hybrid procedures did not provide any proven survival benefits or decrease in stroke rate and spinal ischemia when compared to open surgery in early, mid, or long-term results.

Preoperative Measurements and Planning Sheet for an Endograft With 3 Inner Branches to Repair Aortic Arch Pathologies

Purpose: To present a methodology for aortic arch anatomy measurement to plan and size an arch endograft with 3 inner branches. Technique: The arch endograft is custom manufactured with 3 inner side branches. Computed tomography angiography should be used to measure the clock position, the distances between the supra-aortic vessels, and the length and diameter of the proximal and distal landing zones. On the planning sheet, the vertical axis on the grid represents the spiral stabilizing wire at the 12 o’clock position; the horizontal baseline at 0 mm represents the idealized proximal margin of the innominate artery (IA). The first inner branch for the IA would be at 12:30 clock position and −20 mm from the horizontal baseline, while the second inner branch would be at the 11:30 clock position and at 0 mm. The third inner branch would vary among the different potential positions. Conclusion: Preoperative measurements of aortic arch anatomy can be made using a standard methodology to plan the size and position of inner branches. Future studies will show the potential applicability of a standard 3-inner-branch arch endograft using the planning sheet.

Hybrid and frozen elephant trunk for total arch replacement in DeBakey type I dissection

OBJECTIVE

The study objective was to determine whether hybrid aortic repair yields superior outcomes compared with the conventional surgical approach for DeBakey type I aortic dissection.

METHODS

A retrospective analysis of patients with DeBakey type I dissection admitted to Fuwai Hospital between January 2010 and December 2016 showed that 815 patients (86.9%) underwent open total arch replacement with frozen elephant trunk (frozen elephant trunk group) and 122 (13.1%) underwent hybrid aortic arch repair without deep hypothermic circulatory arrest (hybrid group). We selected 109 pairs of patients for propensity score matching. Outcomes included early postoperative death, a composite of complications, dissected aorta remodeling, long-term survival, and freedom from reoperation.

RESULTS

Early mortality and complication rates were lower in the hybrid group, but the difference was not statistically significant (9.2% vs 17.4%, P = .073; 15.6% vs 25.7%, P = .066). The rates of postoperative renal insufficiency was significantly lower in the hybrid group than in the frozen elephant trunk group (22.9% vs 38.5%, P = .013); liver insufficiency and paraplegia were significantly lower in the hybrid group than in the frozen elephant trunk group (20.2% vs 33.9%, P = .022; 0% vs 6.4%, P = .014). After matched, the 1-year, 3-year, and 5-year survivals were 87.6%, 86.3%, and 82.2%, respectively, in the hybrid group and 80.7%, 76.5%, and 74.6% (P = .071), respectively, in the frozen elephant trunk group.

CONCLUSIONS

Hybrid aortic arch repair is a viable alternative treatment for patients with DeBakey type I aortic dissection, which improves outcomes and promotes remodeling of the dissected thoracic aorta.

Outcomes of Chimney Technique for Preservation of the Left Subclavian Artery in Type B Aortic Dissection

OBJECTIVE

To report outcomes of the chimney technique for preservation of the left subclavian artery (LSA) in patients with type B aortic dissection (TBAD).

METHODS

A retrospective analysis was performed of a prospectively maintained database from August 2012 to October 2017. Primary endpoints were 30 day and overall mortality. Secondary endpoints were technical success, type Ia endoleak, chimney stent occlusion, aortic rupture, stroke, spinal cord ischaemia, and re-intervention rate.

RESULTS

A total of 159 patients (mean age 54 ± 11 years; 141 men) with TBAD were treated using the chimney technique for LSA revascularisation. Acute, subacute, and chronic TBAD accounted for 64%, 28%, and 8% of cases, respectively. One hundred and six cases (67%) were complicated TBAD. One hundred and fifty-six patients (98%) were treated electively, while three (2%) were treated urgently because of intestinal or lower extremity ischaemia. The 30 day mortality and morbidity rates were 2% (3/159) and 4% (7/159), respectively. The technical success rate was 81% (129/159) and immediate type Ia endoleak occurred in 30 (19%) patients. Three major strokes, two spinal cord ischaemia and one aortic rupture, occurred early on. During a mean follow up of 23 ± 16 months (range 1-65 months), three more patients died: from aortic rupture, cerebral haemorrhage, and rectal cancer, respectively. Chimney stent occlusions were observed in four patients and all these chimney stents were self expanding. During follow up, two major strokes, one late type Ia endoleak and one re-intervention, occurred. According to the Kaplan-Meier curve, the estimated one and three year survival rates were 98.1 ± 1.1% and 94.4 ± 2.4%, respectively.

CONCLUSION

Short and mid-term outcomes in the present study demonstrate that the chimney technique is safe and feasible for preservation of the LSA in patients with TBAD, but the durability of chimney stent needs to be evaluated carefully and immediate type Ia endoleak is a concern.

Hybrid aortic arch repair: 10-year experience from India

Purpose

Hybrid aortic arch replacement (HAAR) is emerging as a safe treatment alternative for aortic arch pathologies. HAAR is divided into three groups. We have assessed our outcome for all three types of HAAR.

Method

From January 2007 to December 2016, we have performed 119 endovascular aortic repair (EVAR) of the aorta of which 56 were hybrid aortic arch repair. The hybrid repair entailed aortic arch vessel debranching and concomitant/delayed antegrade ± retrograde EVAR stent grafting of the arch. For group I and II hybrid patients, we debranch the supra-aortic arch vessels without the aid of circulatory arrest. EVAR was performed on the following day. In group III, hybrid antegrade EVAR of the thoracic aorta and arch reconstruction was performed in single stage.

Results

Of the 56 patients, 16 were in group I, 32 in group II, and 8 in group III. Mean age was 59.9 ± 9.4 years with 78.57% (n = 44) being males. Aortic dissection was the primary pathology in 31 (55.36%) patients followed by aneurysm in 24 (42.86%) patients. Marfans syndrome was present in 28.57% (n = 16) patients. Redosternotomy was performed in 10.71% patients (n = 6). Incidence of stroke was 5.38% (n = 3) and there was no patients with renal dysfunction requiring hemodialysis. There were two retrograde aortic dissections and two endoleaks, both in group I patients. Thirty days in-hospital mortality was 5.38% (2 in group I and 1 in group II).

Conclusion

Hybrid aortic arch replacement can be performed with good postoperative outcome. Type II hybrid is better than type I hybrid in our experience. As experience increases, the outcome continues to improve.

Comparison of open surgical versus hybrid endovascular repair for descending thoracic aortic aneurysms with distal arch involvement

Background

Our aim was to compare the efficacies of conventional open thoracotomy and hybrid endovascular technique in patients with descending thoracic aortic aneurysms involving the distal arch.

Methods

Between January 2005 and December 2015, 125 consecutive patients with descending aneurysms involving distal arch underwent open repair via thoracotomy (n=79) or zone 1/2 hybrid endovascular repair (n=46). Surgeries entailing total arch replacement by elephant trunk technique (with sternotomy) and Zone 0 hybrid arch repairs were excluded. Early and late outcomes were compared using propensity scores and inverse-probability-of-treatment weighting (IPTW).

Results

In-hospital mortality rates for open repair (10.1%) and hybrid repair (6.5%) did not differ significantly (P=0.49). Major adverse outcomes included stroke (11.4% vs. 8.7%), paraplegia (2.5% vs. 0.0%) and lung complications (19.0% vs. 6.5%). Once adjusted by IPTW, hospital mortality risk for conventional open repair (OR =4.396; P=0.086) tended to be higher, and there was significant risk of lung complications (OR =4.372; P=0.025). However, both techniques were similar in terms of 30-day mortality (OR =2.745; P=0.257), stroke (OR =2.134; P=0.217), paraplegia (OR =3.639; P=0.407), and midterm survival (OR =1.05; P=0.90). Freedom from reintervention at 10 years was significantly better for open repair (85.2%±7.1%) compared with the hybrid approach (46.3%±11.0%; OR =0.13; P<0.01).

Conclusions

Hybrid arch repair conferred a significantly lower incidence of pulmonary complications, without benefitting perioperative mortality and stroke. However, open repair proved more reliable, showing greater durability. Long-term investigations are needed to confirm the viability and safety of hybrid repair as an alternative treatment in this setting.

Frozen elephant trunk and arch endografts for chronic thoracoabdominal aortic dissections

Chronic aortic dissecting aneurysms (TAAD) presenting after acute Stanford type A or B dissection includes both arch and/or thoracoabdominal aortic aneurysms (TAAA). Approximately 60% of patients who survive surgical treatment of acute type A aortic dissections will require another aortic procedure. Similarly, more than 70% of patients with chronic type B aortic dissections will experience false lumen dilation at 5-year follow-up, often requiring intervention. Open or hybrid aortic repairs of complex TAAD involving the arch and the TAAA are very demanding procedures for both patients and clinicians. Open surgery remains the first line therapy in fit patients. Recent development of branched arch devices has offered an alternative option for high-risk patients. Technical challenges associated with the endovascular management of these complex aneurysms include proximal sealing zone often located in the aortic arch or the ascending aorta, narrow true lumen working space, and aortic branch perfusion by either the true or false lumen, or both. Recent studies have reported encouraging results with endovascular treatment of these complex dissecting aneurysms, especially following open ascending aortic repair. The aim of this review was to describe the available strategies for arch repair in the setting of a chronic TAAD and to determine the subset of patients that can benefit from of a totally endovascular approach.

Endovascular Treatment of Various Aortic Pathologies: Review of the Latest Data and Technologies

The technologies and innovations applicable to endovascular treatment for complex aortic pathologies have progressed rapidly over the last two decades. Although the initial outcomes of an endovascular aortic repair have been excellent, as long-term data became available, complications including endoleaks, endograft migration, and endograft infection have become apparent and are of concern. Previously, the indication for endovascular therapy was restricted to descending thoracic aortic aneurysms and abdominal aortic aneurysms. However, its indication has expanded along with the improvement of techniques and devices, and currently, it has become possible to treat pararenal aortic aneurysms and Crawford type 4 thoracoabdominal aortic aneurysm (TAAA) using the off-the-shelf devices. Additionally, custom-made devices allow for the treatment of arch or more extensive TAAAs. Endovascular treatment is applied not only to aneurysms but also to acute/chronic dissections. However, long-term outcomes are still unclear. This article provides an overview of available devices and the results of endovascular treatment for various aortic pathologies.

Long-term survival and related outcomes for hybrid versus traditional arch repair-a meta-analysis

Background

Surgical interventions for aortic aneurysm and dissection remain associated with high risk of mortality and morbidity. Advances in operative techniques have led to a variety of options for the cardiac surgeon, including endovascular and hybrid approaches. Debate remains over which of these techniques provide optimal outcomes for the patient. The present systematic review and meta-analysis aims to evaluate long term patient survival and identify short-term outcomes for conventional (open) aortic arch repair and hybrid aortic arch repair (HAR).

Methods

An electronic literature search was conducted according to predefined inclusion criteria for hybrid and conventional aortic arch repair surgery. Digitized survival data was extracted from identified studies' Kaplan-Meier curves and used to re-create individual patient data for aggregated survival analysis. Post-operative morbidity and mortality were analyzed using random-effects model meta-analysis.

Results

Nine studies were included, containing 841 hybrid arch repair and 1,182 conventional arch repair patients. Pooled Kaplan-Meier analysis of all patients demonstrated higher survival in hybrid arch repair patients than conventional arch repair patients, however, this was noted to be sensitive to results from a particular study. Overall results showed for the hybrid repair cohort, survival at 1, 2, 3, 5 and 7 years was 87%, 85%, 83%, 78% and 75%, respectively. Survival in the conventional repair cohort at 1, 2, 3, 5 and 7 years was 84%, 82%, 80%, 75% and 71%, respectively. Statistically significant findings from meta-analysis showed hybrid arch repair was associated with lower risk of re-operation for bleeding, while conventional arch repair was associated with reduced risk of spinal cord injury.

Conclusions

Pooled Kaplan-Meier analysis of all studies showed long-term survival outcomes for hybrid and conventional aortic arch repair patients are heterogeneous and sensitive to the results of particular studies. Superior results from particular centres and the low number of comparative studies mean that more data is required to make definitive findings with regards to the long-term survival outcomes of either procedure. Hybrid arch repair was associated with lower risk of re-operation for bleeding, while conventional arch repair was associated with lower risk of spinal cord injury. Surgeons should consider their own center's experience and patient suitability when deciding between hybrid or conventional aortic repair techniques.

Open repair techniques in the aortic arch are still superior

Conventional arch replacement can be carried out in a great majority of patients. Hybrid procedures are often as invasive and technically difficult as conventional ones. Moreover, their immediate results are, in many reported experiences, not better and their long-term results less favourable than the ones observed with conventional methods. So, yes, the open conventional arch replacement is still "the gold standard".

Effects of chronic statin use on 30-day major adverse cardiac and cerebrovascular events after thoracic endovascular aortic repair

BACKGROUND

Cardiac and cerebrovascular complications are major causes of adverse outcomes following thoracic endovascular aortic repair (TEVAR). The benefits of statins have been established, but little is known about their impact on patients undergoing TEVAR. We investigated whether chronic statin use protected against early postoperative major adverse cardiac and cerebrovascular events (MACCEs) after TEVAR.

METHODS

We retrospectively reviewed 211 patients who underwent TEVAR between February 2013 and March 2017 classified into two groups, those with acute aortic syndrome (AAS, N.=79) and those without (non-AAS, N.=132). Patients were subdivided according to preoperative statin therapy for ≥3 months or not. The primary endpoint was 30-day MACCE, defined as myocardial infarction, stroke, arrhythmia, cardiovascular death, or cerebrovascular death. Acute kidney injury (AKI) occurrence within 48 hours was also evaluated. Multivariate logistic regression analysis was performed to identify independent risk factors for MACCEs and AKI.

RESULTS

Incidence of MACCEs (1% vs. 11%, P=0.019) was significantly lower in the statin group than in the no-statin group in non-AAS patients. Multivariate logistic regression analysis revealed statin use (odds ratio 0.85, 95% confidence interval 0.01-0.95, P=0.046) as an independent predictor for MACCE in non-AAS patients. The AKI incidence was significantly higher in the statin group than in the no-statin group in AAS patients (44% vs. 15%, P=0.018).

CONCLUSIONS

In patients undergoing TEVAR, chronic statin use was associated with reduced 30-day MACCEs in non-AAS patients, but not in AAS patients. It might rather be associated with increased risk of AKI in AAS patients.

Conservative management versus endovascular or open surgery in the spectrum of type B aortic dissection

Background

Type B aortic dissection is a life-threatening acute aortic condition often with acute ischemic signs or symptoms. With initial management focusing on alleviating malperfusion and pain, and avoiding propagation of dissection or rupture both systolic blood and pulse pressure should be reduced initially by an aggressive medical approach. In the setting of persistent signs of complications endovascular strategies have replaced open surgery and led to a fourfold increase in early survival and better long-term outcomes.

Methods

An electronic health database search was performed on articles published between January 2006 and July 2017. Publications were included in this review if (I) the index aortic pathology was type B aortic (distal) dissection; (II) when medical management, open surgical replacement or thoracic endovascular aortic repair were among those options; (III) when at least one of all basic outcome criteria such as survival, spinal cord ischemia and cerebrovascular accident was reported; (IV) when ≥15 serial patients were included. A total of 62 studies were eligible and analysed.

Results

Our manuscript has summarized data collected over 12 years on management specific outcomes in the setting of distal aortic dissection and provides an up-to-date interpretation of the published evidence. For complicated cases, treated acutely, the 30-day or in-hospital mortality was 7.3% when managed by endovascular means, whereas the pooled rate for 30-day or in-hospital mortality was 19.0% when subjected to open repair. For acute uncomplicated type B dissection usually treated with blood pressure lowering medications, the pooled 30-day or in-hospital mortality rate was 2.4%. Survival rates at 5 years averaged at 60% (40% mortality). Freedom from any aortic event ranged from 34.0% to 83.9%, underlining an inherent risk of progression and late complications. For chronic complicated type B dissection, the rates of stroke, paraplegia and operative mortality following endovascular repair ranged from 5% to 13%, 2% to 13% and 2 to 13%, respectively, while 5-year survival rates after open repair ranged from 60% to 90%. In chronic uncomplicated type B dissection almost 90% of patients survive initial hospitalization and were subjected to medical management with a 5-year survival of 50-80%. However, up to 20-55% of medically treated patients develop aneurysmal degeneration after 5 years with an unknown risk of rupture.

Conclusions

Currently, the less invasive strategy of endovascular repair (as compared to open surgery) provides improved 30-day or in-hospital survival in the setting of complicated acute type B aortic dissection and may seek broad application. Open surgical aortic reconstruction should be left to experienced aortic centres if endovascular management is not an option.

Hybrid and total endovascular repair of the aortic arch

Background

Recent advances in endovascular technology have enabled minimally invasive repair of the aortic arch, with specifically designed stent-grafts. This article reviews hybrid and total endovascular repair in the management of aortic arch pathology.

Methods

Studies relating to aortic arch management were identified using MEDLINE and Embase, focusing on endovascular repair.

Results

Hybrid arch repair is associated with an early mortality rate of some 12 per cent, and carries significant risk of stroke (up to 15 per cent), paraplegia (up to 6 per cent), retrograde dissection (up to 6·5 per cent) and proximal endoleak (6 per cent). Despite patients being of overall higher perioperative risk, hybrid repair has morbidity and early mortality rates comparable to those of open arch replacement. However, rates of freedom from aortic rupture or reintervention are significantly lower in the longer term, owing to the incidence of endoleak. Total endovascular arch repair may be achieved by the use of parallel stents or in situ fenestration in the emergency setting, or use of custom-made devices (scalloped, fenestrated or branched stent-grafts) in the elective setting. Reports of these relatively novel technologies suggest acceptable short-term outcomes, but long-term data are still awaited.

Conclusion

Repair of aortic arch pathology presents a formidable challenge for endovascular technology. Open aortic arch repair remains the standard in younger, fitter patients, but endovascular technology and experience continue to evolve with encouraging early outcomes and expanding indications.

Complications and Perioperative Management of Patients Undergoing Thoracic Endovascular Aortic Repair

Endovascular treatments have become increasingly common for patients with a variety of thoracic aortic pathologies. Although considered less invasive than traditional open surgical approaches, they are nonetheless complex procedures. Patients undergo manipulation of an often calcified aorta near the origin of the carotid and subclavian vessels and have stents placed in a curved vessel adjacent to a perpetually beating heart. These stents can obstruct blood flow to the spinal cord, induce an inflammatory response, and in rare cases erode into the adjacent trachea or esophagus. Renal complications range from contrast-induced nephropathy to hypotension and ischemia to dissection. Emboli can lead to strokes and mesenteric ischemia. These patients have complex medical histories, and skilled perioperative management is critical to achieving the best clinical outcomes. Here, we review the medical management of the most common complications in these patients including stroke, spinal cord ischemia, renal injury, retrograde dissections, aortoesophageal and aortobronchial fistulas, postimplantation syndrome, mesenteric ischemia, and endograft failure.

Minimally Invasive Techniques for Total Aortic Arch Reconstruction

The cumulative experience with endovascular aortic repair in the descending thoracic and infrarenal aorta has led to increased interest in endovascular aortic arch reconstruction. Open total arch replacement is a robust operation that can be performed with excellent results. However, it requires cardiopulmonary bypass and circulatory arrest and, therefore, may not be tolerated by all patients. Minimally invasive techniques have been considered as an alternative and include hybrid arch debranching, parallel stent graft deployment in the chimney and snorkel configurations, and complete endovascular branched reconstruction with multi-branched devices. This review discusses the evolving use of endovascular techniques in the management of aortic arch pathology and considers their relevance in an era of safe and durable open aortic arch reconstruction.

Objective analysis of midterm outcomes of conventional and hybrid aortic arch repair by propensity-score matching

OBJECTIVE

The aim of this study is to evaluate the objective outcomes of conventional total aortic arch repair (CTAR) and hybrid arch repair by using propensity-score matching to reduce selection bias.

METHODS

Between January 2006 and April 2016, 470 consecutive patients underwent isolated aortic arch repair (excluding hemiarch or partial arch reconstruction, and cases with concomitant cardiac surgeries) at a single cardiovascular institute. We categorized 337 total aortic arch repair with antegrade cerebral perfusion under circulatory arrest as the CTAR group and 58 hybrid aortic arch repair (HAR) with thoracic endovascular aortic repair as the HAR group. Seventy-five patients with scheduled and staged thoracic endovascular aortic repair after total aortic arch repair with elephant trunk were excluded. Then, we compared early and midterm outcomes between the propensity-matched group (43 CTAR vs HAR pairs).

RESULTS

There were no significant differences in 30-day and operative deaths between the CTAR and HAR groups (4.7% [2/43] vs 7.0% [3/43]; P = .4142 and 11.6% [5/43] vs 16.3% [7/43]; P = .5637). Although there were no significant differences in the incidences of other major complications, permanent stroke was observed more frequently in the HAR group (0% [0/43] vs 11.6% [5/43]; P = .0064) compared with the CTAR group. Matching analysis, however, revealed an equivalent 5-year survival rate between the CTAR and HAR groups (80.5% vs 59.9%; P = .1300).

CONCLUSIONS

Matching analysis revealed a significantly greater incidence of stroke in the HAR group but equivalent midterm outcomes in the hybrid group compared with the CTAR group.

Hybrid Procedure with Debranching from the Descending Aorta for Aortic Arch Aneurysm after Previous Open Repair

Aortic arch aneurysms can be treated with hybrid procedures by endovascular exclusion and prior debranching of supra-aortic arteries. We report on a case of symptomatic arch aneurysm following previous supracoronary ascending aorta and hemiarch replacement with a very short proximal landing zone. A successful reconstruction was performed by retrograde revascularization of supra-aortic vessels from the descending aorta and subsequent endovascular repair deploying a proximal stent graft directly above the sinotubular junction with good results in the 4-year follow-up. Retrograde supra-aortic debranching may constitute a suitable approach for hybrid endovascular repair of aneurysms of the aortic arch and the ascending aorta in selected cases.

Short- and Long-term Results of Hybrid Arch and Proximal Descending Thoracic Aortic Repair

Purpose: To evaluate the short- and long-term outcomes of hybrid repair of the arch and proximal descending aorta in a single tertiary center for aortic disease. Methods: A retrospective analysis was performed of 55 patients (median age 67 years; 36 men) who underwent hybrid repair of thoracic aortic pathology with involvement of the arch between January 2005 and May 2015 at a single tertiary center. The pathologies included 40 (73%) with aneurysmal disease, 10 (18%) acute type B aortic dissections, 2 with acute aortic syndrome, an acute type A dissection, and left and aberrant right subclavian artery aneurysms. Seven (13%) procedures were performed as an emergency. Demographics and procedure characteristics were collected for analysis of survival and reinterventions. Results: Complete aortic debranching was performed in 14 (25%) to facilitate endograft placement in zone 0; debranching was partial in 20 (36%) patients for zone 1 deployments and 21 (38%) for zone 2. Primary technical success was achieved in 51 (93%) cases. One patient died in-hospital from aneurysm rupture following aortic debranching prior to stent-graft repair. In another, the stent-graft procedure proved infeasible and was abandoned. The other 2 technical failures were due to type Ia endoleaks. Five (9%) patients died in-hospital (4 of 48 elective and 1 of 7 emergency cases); 2 of these patients died within 30 days (4%). Eight (14%) patients had a stroke, 6 of 48 elective and 2 of the 7 emergency patients. Spinal cord ischemia was reported in 3 (6%) patients. Mean follow-up was 74.6 months. Overall cumulative survival was 70% at 1 year, 68% at 2 years, and 57% at 5 years. Reintervention to the proximal landing zone for type Ia endoleak was required in 6% of cases. The overall rate of aortic reintervention was 18% at 1 year, 21% at 2 years, and 36% at 5 years. Overall extra-anatomic graft patency was 99%. Conclusion: Hybrid repair of the aortic arch and proximal descending thoracic aorta is technically feasible, with acceptable short-term mortality. There is a low rate of proximal landing zone reintervention when hybrid techniques are used to create an adequate proximal landing zone. Extra-anatomic bypass grafts have good long-term patency. Ongoing disease progression means that further distal aortic interventions are often necessary in patients with extensive disease.

Comparison of Total Arch and Partial Arch Transposition During Hybrid Endovascular Repair for Aortic Arch Disease

OBJECTIVE

Total arch transposition (TAT) during hybrid endovascular repair for aortic arch disease is believed to allow a better landing zone, but also to be associated with higher peri-operative mortality than partial arch transposition (PAT). Information on this issue is limited.

METHOD

This study was a retrospective analysis. All 53 consecutive patients with aortic arch disease (41 males, mean age 65.0 years) who underwent hybrid endovascular repair with TAT (zone 0, n=20) or PAT (zone 1 or 2, n=33) from 2008 to 2014 were analyzed retrospectively. The peri-operative and late outcomes of these two groups were compared.

RESULTS

Baseline characteristics, including EuroSCORE II results, were similar in the two groups. After procedures, peri-operative mortalities and stroke rates were similar in the two groups (5.0% vs. 9.1%, p=1.000, and 10.0% vs. 6.1%, p=.627). Interestingly, all four strokes occurred in patients with a type III aortic arch irrespective of transposition type. Primary success rates (80.0% vs. 69.7%, p=.527) and type I endoleak incidences (20.0% vs. 27.3%, p=.744) were not significantly different. During follow up (mean duration 36.9 months), overall survival (89.7% vs. 87.4% at 1 year and 89.7% vs. 79.3% at 3 years; p=.375) and re-intervention free survival rates (78.6% vs. 92.0% at 1 year; 72.0% vs. 62.2% at 3 years, p=.872) were similar in the two groups.

CONCLUSION

Morbidity and mortality were high within the first year of hybrid endovascular therapy for aortic arch disease, implying that candidates for hybrid procedures need to be selected carefully. Hybrid endovascular repair with TAT was found to have peri-operative mortality, stroke, and long-term survival rates comparable with PAT, so hybrid endovascular repair may be considered, irrespective of type of arch reconstruction, when clinically indicated.

Multivariate Analysis of Risk Factors of Cerebral Infarction in 439 Patients Undergoing Thoracic Endovascular Aneurysm Repair

The aim of the study is to identify the potential risk factors of cerebral infarction associated with thoracic endovascular aneurysm repair (TEVAR). TEVAR was developed as a less invasive surgical alternative to conventional open repair for thoracic aortic aneurysm treatment. However, outcomes following TEVAR of aortic and distal arch aneurysms remain suboptimal. Cerebral infarction is a major concern during the perioperative period. We included 439 patients who underwent TEVAR of aortic aneurysms at a high-volume teaching hospital between July 2006 and June 2013. Univariate and multivariate logistic regression analyses were performed to identify perioperative cerebral infarction risk factors. Four patients (0.9%) died within 30 days of TEVAR; 17 (3.9%) developed cerebral infarction. In univariate analysis, history of ischemic heart disease and cerebral infarction and concomitant cerebrovascular disease were significantly associated with cerebral infarction. "Shaggy aorta" presence, left subclavian artery coverage, carotid artery debranching, and pull-through wire use were identified as independent risk factors of cerebral infarction. In multivariate analysis, history of ischemic heart disease (odds ratio [OR] 6.49, P = 0.046) and cerebral infarction (OR 43.74, P = 0.031), "shaggy aorta" (OR 30.32, P < 0.001), pull-through wire use during surgery (OR 7.196, P = 0.014), and intraoperative blood loss ≥800 mL (OR 24.31, P = 0.017) were found to be independent risk factors of cerebral infarction. This study identified patient- and procedure-related risk factors of cerebral infarction following TEVAR. These results indicate that patient outcomes could be improved through the identification and management of procedure-related risk factors.