Influence and Critique of the INSTEAD Trial (TEVAR Versus Medical Treatment for Uncomplicated Type B Aortic Dissection)

Aortic Outcome After Implementation of a Treatment Strategy for Type B Aortic Dissection Involving the Aortic Arch

OBJECTIVE

To evaluate outcomes achieved after implementing a treatment strategy for non-A non-B (NANB) (B 1-2 D according to the latest consensus document of the Society of Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS) acute aortic dissection (AAD).

METHODS

This retrospective observational study adhered to the STROBE checklist. All cases of NANB AAD (B 1-2 D) treated at our Institution between January 2016 and December 2022 were reviewed. Morbidity, mortality, aortic-related reintervention, and remodelling were analysed.

RESULTS

Among 519 cases of acute aortic syndrome, n=22 (4.2%) patients presented with NANB AAD (B 1-2 D) (n=16,72.7% men, mean age 61.5 years+/14.7). Eleven cases were managed with best medical treatment (BMT) alone. Among them, one patient (9.1%) died suddenly two days after diagnosis for aortic rupture. Frozen elephant trunk procedure (FET) was required in the remaining 11 patients: 7(31.8%) needed emergent operation for risks of impending aortic rupture/retrograde AD extension and 4(26.7%) underwent delayed surgery within a month from initial presentation. Overall, in-hospital mortality was 9.1% with both FET and BMT. At a median follow-up of 40 months (range 2 days-200 months) no other deaths occurred. A statistically significant differences in the rate of FL thrombosis (100% vs 55.5%, p=.033) and a significant positive aortic remodelling in zone 3 (p<.001) and 4 (p=0.038) were reported in operated versus medically managed patients.

CONCLUSION

The best treatment for NANB is not established. We advocate for medical stabilisation with an operative approach that favours open surgery in the acute post dissection period, promotes aortic remodelling and carries acceptable risk in centres where FET is performed routinely.

Uncomplicated Type B Aortic Dissection: Challenges in Diagnosis and Categorisation

BACKGROUND

Acute type B aortic dissection (TBAD) is a rare disease that is likely under-diagnosed in the UK. As a progressive, dynamic clinical entity, many patients initially diagnosed with uncomplicated TBAD deteriorate, developing end-organ malperfusion and aortic rupture (complicated TBAD). An evaluation of the binary approach to the diagnosis and categorisation of TBAD is needed.

METHODS

A narrative review of the risk factors predisposing patients to progression from unTBAD to coTBAD was undertaken.

RESULTS

Key high-risk features predispose the development of complicated TBAD, such as maximal aortic diameter > 40 mm and partial false lumen thrombosis.

CONCLUSION

An appreciation of the factors that predispose to complicated TBAD would aid clinical decision-making surrounding TBAD.

Successful surgical repair of traumatic aortic dissection utilizing the Najuta stent graft in a patient with pre-existing situs inversus and anomalous neck vessels

We report the case of a 39-year-old man who underwent surgical repair for traumatic Stanford type B acute aortic dissection. He was involved in a traffic accident, resulting in multiple rib fractures and a sternum fracture. On investigation, he was also found to have anatomical anomalies, namely, situs inversus and abnormality in the aortic arch and neck vessels. Thoracic endovascular aortic repair was performed as it is a less invasive procedure, thus recommended in such cases. A fenestrated thoracic endovascular aortic repair using the Najuta stent graft was found to be effective in this case where the anomalous anatomy was pre-existing.

Retrospective analysis of factors associated with aortic remodeling in patients with Stanford type B aortic dissection after thoracic endovascular aortic repair

Objective

Acute aortic dissection is a life-threatening condition. Thoracic endovascular aortic repair (TEVAR), together with optimized medical treatment, is currently the first line treatment for acute Stanford type B aortic dissection. TEVAR can close the entry tear and reduce mortality. Aortic remodeling after TEVAR can directly affect the patient’s long-term prognosis. The factors that influence aortic remodeling have, however, received insufficient clinical attention and remain unclear. It is very important to identify these factors.

Methods

A total of 100 patients were continuously enrolled from 2011 to 2018 in 2 centers. Relevant data, including time from hospital admission to surgery, medicine use and aortic computed tomography angiography images obtained before and 6 months after surgery were collected. Patients were divided into favorable and adverse aortic remodeling groups, according to the degree of aortic remodeling. Analysis of variance and the chi-square test were performed using SPSS software to compare differences between groups and to determine the factors that influence postoperative aortic remodeling.

Results

The proportion of single-stent implantations was higher in the favorable remodeling group than in the adverse remodeling group (79.5% vs. 53.8% in distal end of stent-graft level and 81.3% vs. 56.4% in diaphragm level, respectively, p < 0.05). The earlier the TEVAR procedure was performed, the better the aortic remodeling (3.4 days vs. 4.8 days in distal stent graft levels, and 3.6 days vs. 4.9 days in diaphragm level, respectively, p < 0.05), the presence of residual distal entry tears in the abdominal aorta also improved aortic remodeling after TEVAR (85.7% vs. 55.1% in the celiac trunk level, and 92.0% vs. 48.9% in the right renal artery level, respectively, p < 0.05).

Conclusion

Single stent-graft implantation and early surgery were associated with favorable aortic remodeling. Distal entry tears were also conducive to aortic remodeling after surgery for aortic dissection.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01571-2.

TEVAR Stent to the False Lumen of a Chronic Type B Aortic Dissection With Aneurysmal Dilatation, When no Other Options Are Left

We report a case of a 72 years-old male referred to us with a 2-year history of an enlarging aortic aneurysm secondary to a chronic Type B aortic dissection and a complete occlusion of the true lumen in the thoracic and abdominal aorta except at the level of visceral arteries origins. Several attempts to recanalize the true lumen was not successful. Because of the patient's high risk for an open repair and the normal size of his thoracic aorta proximal to the celiac artery, we deployed the TEVAR stent to the false lumen to prevent aneurysmal enlargement and rupture. The operation was successful, and the patient recovered without complications and with complete exclusion of the aneurysm on two years follow up.

Certain aortic geometries and hemodynamics are associated with FID development and impact the evolution of uncomplicated type B intramural hematoma during the acute phase

OBJECTIVES

It is difficult to predict the evolution of uncomplicated type B intramural hematoma (IMHB) with a focal intimal disruption (FID) in the acute phase. The aims of this study were to investigate the predictors of FIDs and summarize the risk factors for the evolution of uncomplicated IMHB in the acute phase.

METHODS

Eighty-six patients with uncomplicated IMHB were included and were divided according to the development of an FID during the acute phase: the FID group (n = 32) and the no-FID group (n = 54). Geometric measurements and computed fluid dynamic calculations were based on a computed tomography scan performed on admission. Multivariate logistic regression analysis was used to estimate the predictors of FID development.

RESULTS

Thirty-two (37%) patients developed an FID. Patients with an FID had higher C-reactive protein levels (18.6 ± 2.3 vs 8.1 ± 0.2 mg/dL, P < 0.001) and white blood cell counts (10.3 ± 2.1 vs 7.5 ± 1.7 10⁹ /L, P < 0.001). The no-FID group had lower occurrences of disease progression (15% vs 64%, P < 0.001) and aorta-related mortality (6% vs 25%, P = 0.016). Multivariate logistic regression analysis indicated a significant risk for the occurrence of an FID with a larger maximum aortic diameter (OR, 1.35; 95% CI, 1.05-1.73, P = 0.020), thicker hematoma (OR, 2.20; 95% CI, 1.40-3.48, P = 0.001), and higher oscillatory shear index (per 0.01 unit, OR, 1.74; 95% CI, 1.21-2.49, P = 0.003). The aorta-related mortality during the acute phase was 25% (n = 8).

CONCLUSIONS

Certain aortic conditions, including ta larger aortic diameter, thicker hematoma and higher oscillatory shear stress, are associated with the FID development and result in worse clinical outcomes.

Thoracic endovascular repair (TEVAR) versus open surgery for blunt traumatic thoracic aortic injury

BACKGROUND

Blunt traumatic thoracic aortic injury (BTAI) is a life-threatening surgical emergency associated with mortality up to 8000 per year, most commonly caused by rapid acceleration/deceleration injury sustained through motor vehicle accident and/or blunt thoracic trauma. BTAI has high pre-hospital mortality following the primary injury, with only 10% to 15% of patients surviving long enough to reach the hospital. Open surgical repair had remained the standard treatment option for BTAI since successfully introduced in 1959. However, with technological advances, thoracic endovascular repair (TEVAR) offers an alternative treatment option for BTAI. TEVAR is a less invasive surgical approach for management of these already critical patients; many reports have described favourable early outcomes.Thoracic endovascular repair may appear to be superior to open repair for treatment of BTAI. However, its long-term results and efficacy remain unknown. No randomised controlled trials (RCTs) have provided evidence to support the superiority of the endovascular approach versus open repair in the treatment of BTAI. This review aims to address this matter. This is an update of a review first published in 2015.

OBJECTIVES

To determine whether use of thoracic endovascular repair (TEVAR) for treatment of blunt traumatic thoracic aortic injury (BTAI) is associated with reduced mortality and morbidity when compared with conventional open surgery.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and AMED databases and World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registers to 20 August 2018.

SELECTION CRITERIA

We considered all published and unpublished randomised controlled trials (RCTs) comparing TEVAR and open surgery for BTAI.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed all RCTs identified by the Cochrane Vascular Information Specialist.

MAIN RESULTS

We found no RCTs that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

We found no RCTs conducted to determine whether use of TEVAR for the treatment of BTAI is associated with reduced mortality and morbidity when compared to conventional open repair. Hence, we are unable to provide any evidence to guide the treatment option for this life-threatening condition. To perform a randomised controlled trial to clarify the optimal management of BTAI would be highly challenging due to the natural history of the condition. Despite the lack of RCT evidence, clinicians are moving forward with endovascular treatment of BTAI on the basis of meta-analyses of cohort studies and large clinical series.

Aortic remodeling in Type B aortic dissection after thoracic endovascular aortic repair with an aortic extender cuff implantation

Objective

This study investigated the safety and efficiency of thoracic endovascular aortic repair (TEVAR) plus an aortic extender cuff placement in treating Stanford Type B aortic dissections (TBADs).

Methods

Clinical data on 157 patients with TBADs who underwent TEVAR in two tertiary medical centers from February 2013 to March 2018 were analyzed retrospectively. An estimated mismatch rate >120% was the indication for placement of an aortic extender cuff. Results in the perioperative and follow-up periods (≥3 months) were analyzed, especially those of aortic remodeling.

Results

In total, 106 patients (67.5%) underwent standard TEVAR, and 51 (32.5%) received TEVAR plus an aortic extender cuff placement. The primary technical success rate was 96.8% (152/157). Perioperative adverse events included endoleak (2%, 3/157), spinal cord ischemia (SCI) (1.3%, 2/157), and transient renal failure (0.6%, 1/157), with no between-group differences. The median follow-up was 15 months (range 3–71 months). Ten cases of late stent complications were observed, including three endoleak, one upper limb ischemia, one stent distortion, and five stent graft-induced distal re-dissection (SIDR). Patients with a cuff had less distal re-dissection and fewer second interventions, but the differences lacked significance. In the last follow-up, the TEVAR+Cuff group were found to have better true lumen recovery and false lumen shrinkage, and increased complete false lumen thrombosis in the thoracic and abdominal segments; however, no statistical difference was evident in comparison with the TEVAR group (P>0.05).

Conclusion

TEVAR plus an aortic extender cuff implantation improves remodeling of the dissected thoracic aorta, thus reducing the potential of SIDR. Furthermore, the covered stent with a length of 250 mm does not increase the rate of SCI or paraplegia. However, these results should be confirmed in a larger series of patients with longer follow-up.

Early and midterm outcomes of endovascular treatment for chronic aneurysmal aortic dissection: a retrospective study

BACKGROUND

The aim of this study was to evaluate endovascular treatment for enlarged Stanford type B chronic aneurysmal aortic dissection (CAAD). The conventional treatment for CAAD is open repair; however, the operative mortality is high in extensive prosthetic graft replacements.

METHODS

A retrospective single-center study was conducted on 74 consecutive patients who underwent endovascular treatment for CAAD in the past 8.5 years. In the partial exclusion (PE) group, entry sites in close proximity to the maximum diameter of CAAD were closed using a stent graft and reentry sites were left without closure. In the complete exclusion (CE) group, we attempted to close all entry and reentry sites.

RESULTS

A total of 43 patients (PE group) and 31 patients (CE group) were included with mean ages of 59 and 63 years, respectively. Operative mortalities of 2.3% and 0% were observed in the PE and CE groups, respectively. Complete tear closure was successful in 17 of 31 patients (54.8%) in the CE group. In the PE group, complete thrombosis of the false lumen was achieved in only one case (2.3%). Freedom rates from reentry closure were 90.2%, 86.9%, and 78.2% at 1, 3, and 5 years, respectively. The diameter of the true lumen/aorta changed from 16.9/62.9 mm to 30.2/53.6 mm and from 13.7/55.1 mm to 25.8/51.0 mm in the aortic arch and descending thoracic aorta, respectively. The freedom rates from secondary intervention in successful and unsuccessful CE cases were 92.9% and 69.1%, respectively, at 1 year and 92.9% and 53.7%, respectively, at 3 years.

CONCLUSION

Endovascular treatment for CAAD had favorable early and midterm outcomes.

Short term outcome of thoracic endovascular aortic repair in patients with thoracic aortic diseases

AIM AND BACKGROUND

Open surgical repair for thoracic aortic diseases is associated with a high perioperative mortality and morbidity. Most of type B aortic dissections are uncomplicated and are medically treated which carries a high mortality rate. Thoracic endovascular aortic repair is the first-line therapy for isolated aneurysms of the descending aorta and complicated type B aortic dissection. The aim of this study is to test the safety of early thoracic endovascular aortic repair in patients with uncomplicated type B aortic dissection and patients with thoracic aortic aneurysms.

METHODS

A total of 30 patients (24 men and 6 females; mean age 59 ± 8 years) with uncomplicated type B aortic dissection and descending thoracic aortic aneurysm who underwent endovascular aortic repair in National Heart Institute and Cairo University hospitals were followed up. Clinical follow-up data was done at one, three and twelve months thereafter. Clinical follow-up events included death, neurological deficits, symptoms of chronic mal-perfusion syndrome and secondary intervention. Multi-slice computed tomography was performed at three and six months after intervention.

RESULTS

Of the 30 patients, 24 patients had aortic dissection, and 6 patients had an aortic aneurysm. 7 patients underwent hybrid technique and the rest underwent the basic endovascular technique in whom success rate was 100%. Two patients developed type I endoleak, however both improved after short term follow up. The total mortality rate was 10% throughout the follow-up. Both death and endoleak occurred in subacute and chronic cases, while using TEVAR in acute AD and aneurysm showed no side effects. Early thoracic endovascular aortic repair showed better results and less complications.

CONCLUSION

Along with medical treatment, early thoracic endovascular aortic repair in uncomplicated type B aortic dissections and thoracic aortic aneurysms is associated with better outcome.

Type B aortic dissection: new perspectives

Background

Stanford type B aortic dissection is one of the aortic catastrophes with a high mortality and morbidity that needs immediate or delayed treatment, either surgically or endovascularly. This comprehensive review article addresses the current status of open, endovascular and hybrid treatment options for type B aortic dissections with the focus on new therapeutic perspectives.

Methods

Evaluation of currently available evidence based on randomized and registry data and personal experience.

Results

All type B dissections require prompt medical treatment to prevent aortic rupture. Acute complicated dissections are nowadays treated by endografting to reroute blood flow into the true lumen and promote false lumen thrombosis and future aortic remodeling. In acute uncomplicated situations the position of endografting is less clear and should be further delineated; however, on the long run also in these situations endografting might be protective for future aortic catastrophes in certain patient categories. In the chronic dissection with aneurysm formation of the descending thoracic and/or thoracoabdominal aorta, especially in connective tissue disorders, open surgery offers nowadays the best immediate results with long durability. Thoracic endografting plays only a minor role in these circumstances but branched and fenestrated endografting are very promising techniques. Hybrid techniques can offer the solution for high risk patients that are not suitable for open surgery.

Conclusions

Emergent thoracic endografting is the golden standard for all complicated type B dissections while uncomplicated patients with high-risk features might benefit from endovascular repair. Open surgery is limited for chronic post dissection aneurysms. Aortic surveillance is of paramount importance in all situations.

The IRAD and beyond: what have we unravelled so far?

Acute aortic dissection is a life-threatening condition associated with high morbidity and mortality rates and a long history of challenges to both diagnose and manage this condition successfully. The International Registry of Acute Aortic Dissection (IRAD) was established in 1996 as a global database to understand this old disease better and improve care for dissection. IRAD initially targeted various areas including etiological factors of dissection, modes of presentation, clinical features, physical findings, imaging, management, and outcomes, and is currently branching out in more specific fields such as endovascular intervention, genetic profiling, and functional imaging. Although presenting symptoms and physical findings have not changed significantly over two decades, the widespread use of computed tomography is standard and has improved the diagnostic pathway. Moreover, more patients are managed with appropriate procedures, such as surgery in type A, and endovascular therapy in subsets of type B aortic dissection. With these ongoing improvements in swift diagnostic work-up and therapeutic care, fewer patients are not getting appropriate treatment and more patients survive once they reach hospital.

Intensive Care Management of Thoracic Aortic Surgical Patients, Including Thoracic and Infradiaphragmatic Endovascular Repair (EVAR/TEVAR)

The patient with thoracic aortic disease can present for open or endovascular repair. Thoracic endovascular aortic repair (TEVAR) has emerged as a minimally invasive option for a multitude of aortic pathology, including dissections, aneurysms, traumatic injuries, and ulcers. Postoperative management of these patients depends on the extent of procedure, whether it was open or endovascular, and, finally, on the preoperative comorbidities present. While procedural success has catapulted TEVAR to popularity, midterm results have been mixed. Additionally, periprocedural complications such as paraplegia and renal failure remain a significant morbidity in these patients.

[Pre- and postoperative imaging of type B aortic dissection]

Type B aortic dissections are serious diseases with a 60 to 80 % 5-year survival rate. Although typically managed with a medical treatment, surgery may be necessary in the acute/subacute or the chronic phase if significant complications are encountered. For these patients, CT angiography is the first-line imaging modality, used for indicating and preparing the surgical procedure as well as for follow-up. Physicians in charge of these patients should be familiar with the key reading points. Visceral malperfusion is the most common acute complication, while aneurysmal dilatation of the false lumen is the most common chronic complication, with surgical management generally indicated when the axial diameter of the aorta exceeds 55mm. Endovascular treatment tends to replace open surgery: it requires precise measurements and identification of the entry tear (contribution of 4D-MRA).

Thoracic endovascular repair (TEVAR) versus open surgery for blunt traumatic thoracic aortic injury

BACKGROUND

Blunt traumatic thoracic aortic injury (BTAI) is a life-threatening surgical emergency associated with mortality up to 8000 per year, most commonly caused by rapid acceleration/deceleration injury sustained through motor vehicle accident and/or blunt thoracic trauma. BTAI has high pre-hospital mortality following the primary injury, with only 10% to 15% of patients surviving long enough to reach the hospital. Open surgical repair had remained the standard treatment option for BTAI since successfully introduced in 1959. However, with technological advances, thoracic endovascular repair (TEVAR) offers an alternative treatment option for BTAI. TEVAR is a less invasive surgical approach for management of these already critical patients; many reports have described favourable early outcomes.Thoracic endovascular repair may appear to be superior to open repair for treatment of BTAI. However, its long-term results and efficacy remain unknown. No randomised controlled trials (RCTs) have provided evidence to support the superiority of the endovascular approach versus open repair in the treatment of BTAI. This review aims to address this matter.

OBJECTIVES

To determine whether use of TEVAR for treatment of BTAI is associated with reduced mortality and morbidity when compared with conventional open surgery.

SEARCH METHODS

The Cochrane Vascular Trials Search Co-ordinator searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2015, Issue 7) and clinical trials databases for details of ongoing and unpublished studies.

SELECTION CRITERIA

We considered all published and unpublished randomised controlled trials (RCTs) comparing TEVAR and open surgery for BTAI.

DATA COLLECTION AND ANALYSIS

Two review authors independently reviewed all RCTs identified by the Trials Search Co-ordinator.

MAIN RESULTS

We found no RCTs that met the inclusion criteria for this review.

AUTHORS' CONCLUSIONS

We found no RCTs conducted to determine whether use of TEVAR for the treatment of BTAI is associated with reduced mortality and morbidity when compared to conventional open repair. Hence, we are unable to provide any evidence to guide the treatment option for this life-threatening condition. To perform a randomised controlled trial to clarify the optimal management of BTAI would be highly challenging due to the natural history of the condition. Despite the lack of RCT evidence, clinicians are moving forward with endovascular treatment of BTAI on the basis of meta-analyses and large clinical series.

Management of acute aortic dissection

A new appraisal of the management of acute aortic dissection is timely because of recent developments in diagnostic strategies (including biomarkers and imaging), endograft design, and surgical treatment, which have led to a better understanding of the epidemiology, risk factors, and molecular nature of aortic dissection. Although open surgery is the main treatment for proximal aortic repair, use of endovascular management is now established for complicated distal dissection and distal arch repair, and has recently been discussed as a pre-emptive measure to avoid late complications by inducing aortic remodelling.

Endovascular repair of acute uncomplicated aortic type B dissection promotes aortic remodelling: 1 year results of the ADSORB trial

OBJECTIVES

Uncomplicated acute type B aortic dissection (AD) treated conservatively has a 10% 30-day mortality and up to 25% need intervention within 4 years. In complicated AD, stent grafts have been encouraging. The aim of the present prospective randomised trial was to compare best medical treatment (BMT) with BMT and Gore TAG stent graft in patients with uncomplicated AD. The primary endpoint was a combination of incomplete/no false lumen thrombosis, aortic dilatation, or aortic rupture at 1 year.

METHODS

The AD history had to be less than 14 days, and exclusion criteria were rupture, impending rupture, malperfusion. Of the 61 patients randomised, 80% were DeBakey type IIIB.

RESULTS

Thirty-one patients were randomised to the BMT group and 30 to the BMT+TAG group. Mean age was 63 years for both groups. The left subclavian artery was completely covered in 47% and in part in 17% of the cases. During the first 30 days, no deaths occurred in either group, but there were three crossovers from the BMT to the BMT+TAG group, all due to progression of disease within 1 week. There were two withdrawals from the BMT+TAG group. At the 1-year follow up there had been another two failures in the BMT group: one malperfusion and one aneurysm formation (p = .056 for all). One death occurred in the BMT+TAG group. For the overall endpoint BMT+TAG was significantly different from BMT only (p < .001). Incomplete false lumen thrombosis, was found in 13 (43%) of the TAG+BMT group and 30 (97%) of the BMT group (p < .001). The false lumen reduced in size in the BMT+TAG group (p < .001) whereas in the BMT group it increased. The true lumen increased in the BMT+TAG (p < .001) whereas in the BMT group it remained unchanged. The overall transverse diameter was the same at the beginning and after 1 year in the BMT group (42.1 mm), but in the BMT+TAG it decreased (38.8 mm; p = .062).

CONCLUSIONS

Uncomplicated AD can be safely treated with the Gore TAG device. Remodelling with thrombosis of the false lumen and reduction of its diameter is induced by the stent graft, but long term results are needed.

Stent graft therapy for false lumen aneurysmal degeneration in established type B aortic dissection (FADED) results in differential volumetric remodeling of the thoracic versus abdominal aortic segments

BACKGROUND

Despite optimal medical therapy of type B aortic dissections, false lumen aneurysmal degeneration of these established dissections (FADED) occur over long term (>6 months). The efficacy of thoracic stent grafts (thoracic endovascular aortic repair [TEVAR]) in promoting aortic remodeling when placed at late time points remains controversial and was the focus of this investigation.

METHODS

Utilizing tomographic scans, the volume of 6 distinct aortic compartments were calculated including the stented true lumen and stented false lumen (STL and SFL), below-stent true and false lumens (BSTL and BSFL), and the infrarenal aorta true and false lumens (IRA TL and IRA FL) when applicable. Cross-sectional areas were calculated at 1-cm intervals, collated, and volumetric ratios were derived from preoperative values.

RESULTS

From 2004 to 2011, 21 patients met inclusion criteria. Complete false lumen (FL) thrombosis was achieved in 85.7% of SFL and 26.3% of BSFL. Volumetric analysis demonstrated that 71% of patients had increased STL volume and 71% had decreased SFL. In the below-stent region, 75% of patients had increased true lumen (TL) with 59% concurrently decreased FL volume. The IRA TL volume increased in 85% of patients and the IRA FL also expanded in 75% of this cohort. At the latest time point, overall growth was noted in the infrarenal aortic segment.

CONCLUSIONS

Utilization of TEVAR in patients suffering from FADED can promote TL expansion with concurrent FL regression; however, progressive dilation in the total infrarenal aorta volume may occur and warrants close surveillance.

TEVAR for type B aortic dissection in Japan

TEVAR is a new strategy for treating both acute and chronic type B aortic dissection. The JSC guidelines classify TEVAR as a Class I recommendation for cases of complicated acute type B dissection and a Class IIa recommendation for cases of chronic type B aortic dissection. While TEVAR has been primarily applied to treat complicated acute type B aortic dissection in Europe and the USA, the procedure remains an off-label treatment strategy for aortic dissection in Japan. The current state of TEVAR for type B aortic dissection in Japan from 2001 to 2011 is estimated in the annual reports of the Japanese Association for Thoracic Surgery. The number of acute type B aortic dissection patients treated with transluminal stent grafting increased rapidly after 2008, from 10 cases in 2001 to 76 cases in 2010. Meanwhile, the number acute type B aortic dissection patients treated with any type of surgery has increased gradually, from 100 cases in 2001 to 194 cases in 2009. The number of chronic type B aortic dissection patients treated with transluminal stent grafting increased abruptly in 2010, reaching 346 cases, which accounted for one-third of all surgical procedures for chronic type B aortic dissection. Furthermore, the number of open surgeries for chronic type B aortic dissection has also increased gradually, from 401 cases in 2001 to 947 cases in 2011. At present, open surgery, TEVAR and hybrid procedures are available to treat patients with type B aortic dissection. The use of a multidisciplinary team approach is mandatory when selecting the appropriate surgical strategy.

Debate: Whether level I evidence comparing thoracic endovascular repair and medical management is necessary for uncomplicated type B aortic dissections

Type B aortic dissections continue to be one of the most challenging clinical scenarios confronting vascular surgeons. In the era of open surgery, the therapeutic options were limited to medical management of hypertension and large open thoracoabdominal operations. In the current endovascular era, the operative strategies have become less invasive but the questions regarding therapeutic approaches have become more numerous and complex. In patients with acute uncomplicated type B aortic dissections, we are still unsure as to which patients are best treated with medical therapy alone or with the addition of early endovascular repair. Data from single centers and registries have provided some guidance; however, questions remain. Perhaps level 1 evidence from well-designed randomized controlled trials will answer all of our questions. This is the topic of the current debate.

Current evidence for thoracic aorta type B dissection management

Aortic dissection is a devastating cardiovascular condition and represents the most common aortic emergency. Outcome is determined by the type and extent of dissection and the presence of associated complications requiring early diagnosis and treatment. Aortic dissection is defined as acute within 14 days from onset and chronic after that time period. The natural course of type B dissection is determined by 2 elements, early and chronic complications. An uncomplicated acute type B dissection is less frequently lethal but it is not totally benign. Some peculiar issues must be taken into account, such as the high probability of complications development in a dissected aorta and the poor long-term prognosis on medical treatment alone. Then, it would be helpful to identify which patients with uncomplicated type B dissection will have a poorest aortic prognosis over time in order to apply an early intervention.

Treatment of acute type-B aortic dissection: thoracic endovascular aortic repair or medical management alone?

OBJECTIVES

This study sought to evaluate the early and long-term effect of thoracic endovascular aortic repair (TEVAR) on type-B acute aortic dissection (AAD).

BACKGROUND

Uncomplicated type-B AAD is generally treated with medical management; complicated dissections require surgery or TEVAR. Studies have demonstrated that long-term outcomes with medical management are suboptimal. Therefore, we sought to determine the long-term effect of TEVAR compared with medical management alone on type-B AAD.

METHODS

From January 2004 to May 2008, 193 consecutive patients in 2 hospitals were treated and retrospectively placed into 1 of 2 groups: 1) the TEVAR group-type-B AAD treated with TEVAR and antihypertensive medications (n = 152); and the 2) medicine group-uncomplicated type-B AAD treated medically alone (n = 41). All TEVAR procedures were performed in the acute phase.

RESULTS

There were no significant differences in demographics, comorbidity profiles, or early events between groups. The cumulative freedom from all late adverse events at 1, 3, and 5 years was 97%, 89%, and 67% in the TEVAR group and 97%, 63%, and 34% in the medicine group. Log-rank tests showed that medically treated patients had more late adverse events than TEVAR-treated patients did (p = 0.003). The 5-year cumulative survival rate from all-cause death was not significantly different between the 2 groups.

CONCLUSIONS

Patients with type-B AAD treated with TEVAR experienced fewer late adverse events than those treated with medical management, but there was no significant difference among the groups in 5-year mortality rates. Further studies of longer-term survival rates are needed to determine whether TEVAR could be an effective treatment for type-B AAD.

Endovascular Versus Medical Therapy for Uncomplicated Type B Aortic Dissection

Background:

Uncomplicated type B dissections have been traditionally managed with antihypertensive therapy. In the endovascular era, this dictum has been revisited. This review pooled the available studies to compare the outcomes of best medical therapy (BMT) to thoracic endovascular aortic repair (TEVAR) for uncomplicated type B dissections.

Methods:

A literature search was performed to identify studies on uncomplicated type B dissections managed with BMT with and without TEVAR. The primary outcome measures were mortality rates at 30 days and at 2 years following intervention.

Results:

A total of 6 studies included 123 patients who underwent TEVAR/BMT, and 566 patients who had BMT alone. The mortality rates at 30 days (6.5% TEVAR/BMT vs 4.8% BMT, P = .21) and at 2 years (9.7% vs 11.9%, P = .32) were similar. Renal failure was greater in TEVAR/BMT (15.4% vs 2.1%, P < .01). Rates of surgical reintervention/intervention were similar (17.6% vs 20.1%, P = .31).

Conclusion:

The TEVAR with BMT does not provide survival benefit compared to BMT alone, 2 years following uncomplicated type B aortic dissection.

Progress in management of malperfusion syndrome from type B dissections

OBJECTIVE

Malperfusion syndrome is a known predictor of poor outcomes in acute type B dissection. We describe our experience with revascularization in the acute setting.

METHODS

Patients undergoing intervention for ischemia complicated acute type B dissection between November 1999 and March 2011 were reviewed. Details of presenting condition, surgical intervention, and postoperative course were collected. Descriptive and inferential statistical analyses included survival and freedom from reintervention using Cox proportional hazards models.

RESULTS

A total of 61 patients were identified with malperfusion in at least one territory, including spinal cord 7/61 (12%), mesenteric 37/61 (61%), renal 45/61 (73%), and lower extremity 38/61 (62%). Thoracic stent grafts were placed in all patients, and 41% of patients required adjunctive branch vessel stenting. After intervention, resolution of the ischemia was reported in 57/61 (93%) of patients. The 30-day/in-hospital mortality was 21.3%. The 6-month, 1-year, and 5-year survival was 75% (95% CI, 65%-87%), 71% (95% CI, 61%-84%), and 56% (95% CI, 43%-74%), respectively. The 6-month, 1-year, and 5-year freedom from reintervention was 84% (95% CI, 75%-95%), 76% (95% CI, 65%-90%), and 42% (95% CI, 24%-76%), respectively. Territory of ischemia was not independently associated with mortality, but placement of a stent graft proximal to the subclavian artery was associated with poor outcome hazard ratio 2.91 (95% CI, 1.09-8.11; P = .034).

CONCLUSIONS

Malperfusion in any territory at the time of presentation in patients with type B dissections can be treated with endovascular intervention with acceptable outcomes. Opposed to branch vessel intervention alone, increased aortic intervention with regard to proximal coverage may signify more serious disease is associated with worse outcome.

Endovascular versus conventional medical treatment for uncomplicated chronic type B aortic dissection

BACKGROUND

Aortic dissection is a potentially life-threatening condition that occurs when a tear forms in the inner lining of the aorta. It has traditionally been treated by blood pressure control (medical treatment) or open surgery, both with high mortality rates. More recently stent-graft repair has been suggested as an alternative.

OBJECTIVES

To identify the best management for uncomplicated (without rupture of the organs or malperfusion of the extremities) subacute or chronic type B aortic dissection.

SEARCH METHODS

The Cochrane Peripheral Vascular Diseases Group Trials Search Co-ordinator searched their Specialised Register (last searched May 2012) and CENTRAL (2012, Issue 4). Clinical trials databases were searched for ongoing or unpublished studies.

SELECTION CRITERIA

All randomised controlled trials designed to compare the outcome of uncomplicated (without rupture of the organs or malperfusion of the extremities) chronic (occurring more than two weeks previously) type B aortic dissection when treated by stenting adjunctive to best medical treatment versus best medical treatment alone were included.

DATA COLLECTION AND ANALYSIS

Data on all cause and aorta-related mortality at two years was collected and analysed. In addition, secondary outcome measures were analysed, including morbidity, complications (additional endovascular or open surgery for rupture, expansion or malperfusion) and quality of life.

MAIN RESULTS

A single trial was identified that fulfilled the inclusion criteria (INSTEAD trial). The two-year all cause survival was not statistically significantly different between study groups (95.6% ± 2.5% in the optimised medical therapy (OMT) group and 88.9% ± 3.7% in the thoracic endovascular aneurysm repair (TEVAR) + OMT group; log rank test P = 0.15).

AUTHORS' CONCLUSIONS

Overall, the data at two years were insufficient to make any practice recommendations. However, the data on the anatomic remodeling of dissected aortas observed after TEVAR + OMT is encouraging and future studies should follow up cases for at least five years to see if early endovascular interventions, even in stable initially uncomplicated type B patients, are of long-term benefit.