Criteria for endovascular intervention in type B aortic dissection

Systematic review of the effect of cerebrospinal fluid drainage on outcomes after endovascular type B aortic dissection repair

OBJECTIVE

The aim of the present systematic review was to determine whether prophylactic use of cerebrospinal fluid drainage (CSFD) contributes to a lower rate of spinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR) for type B aortic dissection (TBAD).

METHODS

PubMed, Embase, Web of Science and Cochrane Library databases were systematically searched to identify all relevant studies reported before May 7, 2023. A systematic review was conducted in accordance with PRISMA guidelines (PROSPERO registration no. CRD42023441392). The primary outcome was permanent SCI. Secondary outcomes were temporary SCI and 30-day/in-hospital mortality. The data were presented as the pooled event rates (ERs) and 95% confidence intervals (CIs).

RESULTS

A total of 1008 studies were screened, of which 34 studies with 2749 patients were included in the present analysis. The mean Downs and Black quality assessment score was 8.71 (range, 5-12). The pooled rate of permanent SCI with prophylactic CSFD was identical to that without prophylactic CSFD (2.0%; 95% CI, 1.0-3.0; P = 0.445). No statistically significant difference was found between the rates of permanent SCI with routine vs. selective prophylactic CSFD (P = 0.596). The pooled rate of temporary SCI was 1.0% (95% CI, 0.00-1.0%). The pooled rate for 30-day or in-hospital mortality was not significantly different (P = 0.525) in patients with prophylactic CSFD (4.0, 95% CI 2.0-6.0) or without prophylactic CSFD (5.0, 95% CI 2.0-7.0).

CONCLUSIONS

The systematic review has shown that prophylactic CSFD was not associated with a lower rate of permanent SCI and 30-day or in-hospital mortality after TEVAR for TBAD.

Aortic Arch Debranching and Thoracic Endovascular Aortic Repair (TEVAR) for Type B Aortic Dissection

BACKGROUND

Since its introduction, thoracic endovascular aortic repair (TEVAR) has revolutionized the treatment of type B aortic dissections (TBADs). However, the proximal aspect of the aortic pathology treated may infringe on the origin of the left subclavian artery or even more proximally. Hence, to ensure durable outcomes, the origin of these vessels needs to be covered, but an extra-anatomical bypass is required to perfuse vital branches, known as aortic arch debranching. This series aims to describe and delineate the disparities of aortic arch debranching during TEVAR for TBAD.

METHODS

A retrospective review and analysis of a multicenter international database was conducted to identify patients with TBAD treated with TEVAR between 2005 and 2021. Data analyzed included patient demographics, disease characteristics, operative characteristics, and postoperative outcomes with follow-up on mortality and reintervention. All statistical analyses were carried out using IBM SPSS 26. Patient survival was calculated using a Kaplan-Meier survival analysis, and a P value of less than 0.05 was considered statistically significant.

RESULTS

A total of 58 patients were included in the analysis, of which 27 (46.6%) presented with complicated disease and 31 were uncomplicated, of which 10 (17.2%) were classed as high risk and 21 (36.2%) low risk. Zone 2 was the most common proximal landing zone for the stent graft. Left subclavian artery bypass was performed selectively (26%), with 1 stroke occurring, likely due to embolic reasons. A further 6 underwent more proximal aortic debranching before TEVAR (10%) and was a significant risk factor for mortality and the number of stents deployed. The overall rates of reintervention and mortality were 17.2% (n = 10) and 29.3% (n = 17).

CONCLUSIONS

Aortic arch debranching and TEVAR for TBAD is associated with significant mortality. Future developments to treat aortic arch pathology could incorporate branched graft devices, eliminating the need for debranching, improving stroke rates, and reducing future reinterventions.

Endovascular aortic arch repair: A comparison of outcomes and current trends

OBJECTIVE

Application of thoracic endovascular aortic repair (TEVAR) to the aortic arch has been met with the development of purpose-made endoprostheses for on-label use in the aortic arch. An appraisal of the clinical efficacy of each major device is therefore useful towards informing clinical decision making for patients eligible for endovascular arch repair (EAR) rather than open surgical reconstruction.

METHODS

A literature review of publications outlining clinical experience with the RELAY™ Branched and Zenith™ devices was undertaken, and the results therefrom analysed to evaluate the clinical efficacies of each device.

RESULTS

Early- and long-term mortality rates associated with EAR appear favourable, especially compared against open surgical repair. EAR is also associated with good neurological outcomes and target vessel patency rates. However, EAR continues to be associated with substantial reintervention rates.

CONCLUSIONS

At the present stage, EAR represents a promising alternative option to open surgical reconstruction in patients that meet its eligibility criteria. Though there remains a substantial learning curve associated with EAR, its favourable outcome profile is likely to increase its applicability in the future.

Changing Management of Type B Aortic Dissections

The purpose of this manuscript is to review recent trends in the management of acute type B aortic dissection. Due to its efficacy and low morbidity, thoracic endografting has rapidly been adopted as the treatment of choice for most patients with malperfusion or rupture as a consequence of acute aortic dissection. This technology is increasingly applied to patients without rupture or malperfusion, so-called "uncomplicated" dissections, to reduce the incidence of late aneurysmal degeneration in the ungrafted segments of the thoracoabdominal aorta. A variety of techniques have been proposed, including intentional rupture of the dissection membrane to obliterate the false lumen as well as the candy-plug technique to eliminate retrograde flow in the false lumen.

Ethnic & Sex Disparities in Type B Aortic Dissection Patients Undergoing Thoracic Endovascular Aortic Repair: An International Perspective

BACKGROUND

There has been a revolution in the management of type B aortic dissection (TBAD) over the last 2 decades due to the increasing development of endovascular techniques, with the prime example being thoracic endovascular aortic repair (TEVAR). However, many controversies concerning the use of TEVAR in TBAD exist. For instance, there is little available evidence suggesting any differences in demographics, disease characteristics, intervention technicalities, and clinical outcomes between males and females as well as different ethnicities when undergoing TEVAR for TBAD, both in the short and long term. Also, there is no risk prediction model/tool available. The objective of this international study is to describe and delineate the disparities between male and female patients of different ethnicities in terms of demographics, disease and interventional characteristics, and clinical outcomes.

METHODS

Over 17 years a total of 58 TBAD patients were admitted to 2 tertiary vascular centres and treated using TEVAR. Mortality, postoperative complications and reintervention data were recorded for the first 30 days after the procedure as well as during follow-up. Follow-up for all patients lasted until the study endpoint or until a patient's death. Data were analysed retrospectively using IBM SPSS statistical package 26 for Windows.

RESULTS

The mean age was similar between the 2 groups, with the majority of patients in both being Caucasian. More than half of the males had complicated TBAD, while the majority of females were classed as having uncomplicated disease. The most commonly utilized proximal and distal landing zone for the TEVAR stent graft was zone 2 and zone 4, respectively. The mean proximal stent diameter was significantly larger in males compared to females (P = 0.004). The difference in mean distal diameter between the 2 groups was insignificant (P = 0.721). The mean total stent coverage of the thoracic aorta was 251.3 mm in male patients compared to 291.2 mm in females (P = 0.203). A total of 32 patients underwent adjunctive procedures. Seven (17%) of the males had one or more postoperative complications compared to 2 (12%) females. Nine (22%) males underwent a reintervention procedure post TEVAR compared to only 1 (6%) female (P = 0.136). Overall, males had a mortality rate of 24% (n = 10) compared to 41% of females (n = 7) (P = 0.201). Estimated survival of males and females post TEVAR was 80.4 ± 9.6 months and 69.7 ± 14.4 months (P = 0.428). For the total population, the number of stent grafts was inversely correlated with mortality.

CONCLUSIONS

Despite the favourable clinical outcomes achieved by TEVAR in TBAD, there remains a grey area concerning its management. Thus, it is important to perform risk stratification of individual patients using their demographics and comorbidities, particularly scrutinizing patient sex and ethnic origin, when considering intervention for TBAD to achieve optimum results.

Cost analysis of thoracic endovascular aortic repair in type B aortic dissection: How much does quality cost?

BACKGROUND

Aortic dissection (AD) is a life-threatening medical emergency that affects an estimated 3-4 people per 100,000 annually, with 40% of cases classified as type B AD (TBAD). TBAD can be further classified as being complicated (co-TBAD) or uncomplicated (un-TBAD) based on the presence or absence of certain features such as malperfusion and rupture. TBAD can be managed conservatively with optimal medical therapy (OMT), or invasively with open surgical repair (OSR) or thoracic endovascular aortic repair (TEVAR), depending on several factors such as type of TBAD and its clinical acuity. The cost-effectiveness, or cost-benefit profile, of these strategies must be given equal consideration. However, TBAD studies featuring cost analyses are limited within the literature. This narrative review aims to address the gap in the literature on cost-effectiveness of TBAD treatments by providing an overview of cost analyses comparing OMT with TEVAR in un-TBAD and TEVAR with OSR in co-TBAD. Another aim is to provide a market analysis of the commercially available TEVAR devices.

METHODS

A comprehensive literature search was performed using several search engines including PubMed, Ovid, Google Scholar, Scopus, and Embase to identify and extract relevant studies.

RESULTS

Several TEVAR devices are available commercially on the global market costing $12,000-19,495. Nevertheless, the Terumo Aortic RELAY® stent graft seems to be the most cost-effective, yielding highly favourable clinical outcomes. Despite the higher initial cost of TEVAR, evidence in the literature strongly suggest that it is superior to OMT for un-TBAD on the long-term. In addition, TEVAR is well established in the literature as being gold-standard repair technique for co-TBAD, replacing OSR by offering a more optimal cost-benefit profile through lower costs and improved results.

CONCLUSIONS

The introduction of TEVAR has revolutionized the field of aortovascular surgery by offering a highly efficacious and long-term cost-effective treatment for TBAD.

Fate and Consequences of the False Lumen after TEVAR in Type B Aortic Dissection

BACKGROUND

Type B aortic dissection (TBAD) occurs due to an entry tear in the intimal layer of the aorta distal to the origin of the left subclavian artery where blood enters the newly formed false lumen (FL) and extends distally or proximally to form a dissection over an indeterminate length of the aorta which, over time, may eventually rupture. Thoracic endovascular aortic repair (TEVAR) aims to seal off the entry tear proximally with the stent-graft, occluding the origin of the dissection and excluding the FL. Nevertheless, in some cases, the perfusion to the FL is maintained, hindering the aortic remodelling process and increasing the risk of aneurysmal degeneration and rupture, particularly in the abdominal aorta where evidence suggest that remodelling is slower. This review examines the long-term effects of a patent or partially thrombosed FL on clinical outcomes following TEVAR in TBAD, also highlighting the pathological processes behind negative aortic remodelling. Another aim of this review is to provide an overview and appraisal of the currently available techniques for managing a patent or partially thrombosed FL to prevent long-term morbidity occurring.

METHODS

A comprehensive literature search was performed using several search engines including PubMed, Ovid, Google Scholar, Scopus, and Embase to identify and extract relevant studies.

RESULTS

Evidence in the literature show that a partially thrombosed FL is more dangerous than a patent FL due to the occlusion of the distal re-entry tears, impeding outflow and increasing mean arterial and diastolic pressures, whereas the latter is decompressed via distal re-entry sites. FL thrombosis and satisfactory remodelling is sometimes achieved in as few as 40% of patients after TEVAR due to the maintained perfusion of the FL either at the level of the thoracic or abdominal aorta. However, although the thoracic aorta is predominantly covered by the TEVAR stent-graft, poorer remodelling and more dilation is seen in the abdominal aorta. Several techniques are available to embolize the FL, including the Provisional Extension to Induce Complete Attachment, Stent Assisted Balloon Induced Intimal Disruption and Relamination in Aortic Dissection Repair, candy-plug, and Knickerbocker techniques.

CONCLUSIONS

The management of TBAD is invariably TEVAR to seal off the proximal entry tear while extending the repair distally to completely exclude the FL. A risk of aortic wall dilatation distal to TEVAR stent-graft remains; hence, regular monitoring and accurate imaging are essential. At present, a patent FL can be treated using a range of different endovascular techniques.

The misnomer of uncomplicated type B aortic dissection

BACKGROUND

Acute type B aortic dissection (TBAD) is a rare condition that can be divided into complicated (CoTBAD) and uncomplicated (UnCoTBAD) based on certain presenting clinical and radiological features, with UnCoTBAD constituting the majority of TBAD cases. The classification of TBAD directly affects the treatment pathway taken, however, there remains confusion as to exactly what differentiates complicated from uncomplicated TBAD.

AIMS

The scope of this review is to delineate the literature defining the intervention parameters for UnCoTBAD.

METHODS

A comprehensive literature search was conducted using multiple electronic databases including PubMed, Scopus, and EMBASE to collate and summarize all research evidence on intervention parameters and protocols for UnCoTBAD.

RESULTS

A TBAD without evidence of malperfusion or rupture might be classified as uncomplicated but there remains a subgroup who might exhibit high-risk features. Two clinical features representative of "high risk" are refractory pain and persistent hypertension. First-line treatment for CoTBAD is TEVAR, and whilst this has also proven its safety and effectiveness in UnCoTBAD, it is still being managed conservatively. However, TBAD is a dynamic pathology and a significant proportion of UnCoTBADs can progress to become complicated, thus necessitating more complex intervention. While the "high-risk" UnCoTBAD do benefit the most from TEVAR, yet, the defining parameters are still debatable as this benefit can be extended to a wider UnCoTBAD population.

CONCLUSION

Uncomplicated TBAD remains a misnomer as it is frequently representative of a complex ongoing disease process requiring very close monitoring in a critical care setting. A clear diagnostic pathway may improve decision making following a diagnosis of UnCoTBAD. Choice of treatment still predominantly depends on when an equilibrium might be reached where the risks of TEVAR outweigh the natural history of the dissection in both the short- and long-term.

RELAYTM Branched–International Results of Vessel Patency and Reintervention

Background

Surgical intervention remains the mainstay treatment for aortic arch aneurysm and dissection, but the high mortality and morbidity rates have led to a need for the development of minimally invasive alternatives to arch reconstruction. RELAY™ Branched (Terumo Aortic, Inchinnan, UK) represents a viable option for complex endovascular aortic arch repair. We present multi-center data from Europe documenting the efficacy of the endograft in terms of its target vessel patency and reintervention rates.

Methods

Prospective data collected between January 2019 and January 2022 associated with patients treated with RELAY™ single-, double-, and triple-branched endoprostheses from centers across Europe was retrospectively analyzed with descriptive and distributive analysis. Follow up data from 30 days and 6-, 12-, and 24 months postoperatively was included. Patient follow up was evaluated in terms of target vessel patency and reintervention rates.

Results

Technical success was achieved in 147 (99.3%) cases. Over 24 months period, target vessel patency was maintained in 80.2% (n = 118) of patients. Target vessel cannulation was achieved in 146 (99.3%) cases. Over the 24-month follow-up period, 30 reintervention procedures were required, of which 29 (97%) took place within the South Europe region which accounted for 19.6% (n = 29) of total cases. Zero reinterventions were required in patients that were treated with single- or triple-branched endoprostheses.

Discussion

The data presented herein demonstrates that RELAY™ Branched is a technically efficacious device for endovascular aortic arch repair and is associated with favorable target vessel patency and reintervention rates. Key design features of the endoprosthesis and good perioperative management can contribute greatly to mitigating reintervention and loss of vessel patency following endovascular aortic arch repair.