Uncomplicated Type B Aortic Dissection: Challenges in Diagnosis and Categorization.

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.

Population risk profile analysis of acute uncomplicated type B aortic dissection patients undergoing thoracic endovascular aortic repair.

BACKGROUND: Uncomplicated type B aortic dissection (unTBAD) comprises the estimated majority of type B aortic dissection (TBAD), presenting without any of the complications associated with complicated TBAD (coTBAD). Although first-line treatment for coTBAD is thoracic endovascular aortic repair (TEVAR), and despite the fact that TEVAR has proven its safety and effectiveness in the treatment of unTBAD, unTBAD is still being predominantly managed conservatively with medical therapy, with a small proportion of patients being offered TEVAR. AIMS: The main scope of this review is to highlight the evidence in the literature of the demographic characteristics and associated co-morbidities of unTBAD patients undergoing TEVAR in order to produce a risk stratification system to achieve favourable outcomes. METHODS: A comprehensive literature search was conducted using multiple electronic databases including PubMed, Ovid, Scopus, and EMBASE. RESULTS: Multiple demographic characteristics and associated co-morbidities of unTBAD patients affecting TEVAR outcomes were identified, assessed, and investigated, including age, gender, race, genetics, medical conditions, such as hypertension and diabetes, and lifestyle factors such as smoking. Most factors were associated with increased risks of mortality and morbidity, while others, such as race, were identified as being protective against those when it comes to TEVAR. CONCLUSION: Despite the favourable results yielded by TEVAR in unTBAD, there remains a grey area concerning its management. Thus, it is important to incorporate the demographics and co-morbidities of unTBAD patients' when into clinical judgement when assessing indications for TEVAR intervention to ensure optimum results can be achieved.

Fate and Consequences of the False Lumen After Thoracic Endovascular Aortic Repair 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.

Endovascular solutions for abdominal aortic aneurysms: A comparative review of clinical outcomes with custom-made endografts.

BACKGROUND: The introduction of endovascular aortic repair has revolutionised the treatment of abdominal aortic aneurysms, replacing open surgical repair for the majority of elective cases due to its optimal morbidity and mortality. Several endovascular aortic repair stent grafts exist commercially, one of which is the Fenestrated Anaconda™ by Terumo Aortic which benefits from a very innovative design, unique custom-made approach and highly favourable results. AIMS: The main scope of this narrative review is to provide a comprehensive overview of endovascular aortic repair clinical outcomes using the Fenestrated Anaconda™ stent-graft and comparing these with its market competitor, Zenith. This review will also examine the evidence in the literature on the Anaconda™'s custom-made approach. METHODS: A comprehensive literature was conducted on several search engines including PubMed, Google Scholar, Ovid, Scopus and Embase to collate the evidence in the literature on clinical outcomes achieved with the Fenestrated Anaconda™ and Zenith including, but not limited to, survival, technical success, target vessel patency, endoleak, reintervention and aneurysm sac regression. RESULTS: The Fenestrated Anaconda™ is associated with excellent results, including highly favourable survival, technical and clinical success and target vessel patency rates, very low need for reintervention or conversion, and minimal incidence of complications such as endoleak and endograft migration. The Fenestrated Anaconda™ also drives significant sac regression and aortic remodelling. In addition, its unique custom-made approach enables it to treat highly complex aortic anatomy as well as to 'rescue' failed competitor grafts. CONCLUSION: The Fenestrated Anaconda™ has proven that it is a very safe, highly applicable and extremely effective device used for complex aortic and/or iliac pathology based on its novel design and outstanding track record of clinical outcomes.

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.

Correlative effect between sac regression and patient longevity following endovascular solution for abdominal aortic aneurysms: an international analysis.

INTRODUCTION: Since the introduction of endovascular aortic repair (EVAR) it has become the mainstay treatment for abdominal aortic aneurysms. Several EVAR devices exist commercially, yet, the Terumo Aortic Fenestrated Anaconda™ endograft has demonstrated outstanding results. Evidence in the literature suggests that sac regression could be linked to patient survival and longevity. The main scope of this study is to evaluate sac regression and survival achieved using the Fenestrated Anaconda™ endograft and to discuss relevant literature. MATERIALS AND METHODS: The current study represents a nine-year cross-sectional international analysis of custom-made Fenestrated Anaconda™ device. For the statistical analysis, SPSS 28 for Windows and R were utilised. Pearson chi-square analysis was used to assess differences in cumulative distribution frequencies between select variables. Statistical significance for all two-tailed tests was set at p < 0.05. RESULTS: A total of 5,058 patients received the Fenestrated Anaconda™ in this study, either due to unsuitable/complex anatomy for competitor devices (n = 3,891) or based on surgeon preference (n = 1,167). A sac regression of 0-30% was observed in 4,772 (94.3%) over the first four years post-EVAR. Here, 99.6% of patients receiving the Fenestrated Anaconda™ due to unsuitable/complex anatomy for competitor devices and 76.8% based on surgeon preference had 0-30% sac regression. During years 5-9 of follow-up, all patients had 20-45% sac regression. Patient survival during the first six years post-EVAR was 100% but dropped to 77.1% in years 7-9. Survival differed between categorical patient subsets based on the indication. DISCUSSION: The Fenestrated Anaconda™ has been proven to be a highly effective EVAR endograft. Evidence in the literature clearly demonstrates that sac regression is an accurate prognostic factor for patient survival and longevity.

Thoraflex Hybrid vs. AMDS: To replace the arch or to stent it in type A aortic dissection?

BACKGROUND: Acute type A aortic dissection (ATAAD) is a life-threatening medical emergency that requires urgent surgical intervention. The mainstay surgical approach to treating ATAAD with aortic arch involvement is total arch replacement (TAR). The frozen elephant trunk (FET) procedure involves TAR with hybrid endovascular stenting of the DTA in a single step using a hybrid prosthesis (HP). The prime example of a FET HP is Thoraflex Hybrid Prosthesis (THP). Another treatment option is the novel Ascyrus Medical Dissection Stent (AMDS) that is deployed as a non-covered stent along with the aortic arch as an adjunct to prior hemi-arch replacement. AIMS: This comparative review highlights the clinical applications and outcomes of THP and AMDS in the treatment of ATAAD and discusses the main differences between both approaches. METHODS: A comprehensive literature search was conducted using multiple electronic databases including PubMed, Google Scholar, Ovid, Scopus and Embase. RESULTS: TAR with FET can be considered the superior approach to managing ATAAD with arch involvement relative to AMDS with hemi-arch replacement due to more optimal clinical outcomes. Upon comprehensively searching the literature, early mortality was substantially lower with FET ranging from 0-11% compared to 12.5-18.7% using AMDS, with more favourable long-term survival. The incidence of kidney injury and new stroke post-FET ranged from 3-20% and 5-16%, and 11-37.5% and 0-18.8% following AMDS implantation. However, evidence supporting the use of AMDS is extremely limited. Meanwhile, TAR with FET is a well-established and well-described procedure for ATAAD repair. CONCLUSION: Despite the novel nature of AMDS, its clinical safety and effectiveness are yet to be proven. In conclusion, THP remains the best evidenced-based approach to treat ATAAD in this era.

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.

Dynamic and Static Vessel Malperfusion as a Consequence of Acute Type B Aortic Dissection.

BACKGROUND: Acute type B aortic dissection (TBAD) is relatively uncommon with an estimated incidence of up to 8 cases per 100,000 individuals annually. It can be classified based on presenting clinical and radiological features into complicated and uncomplicated. Following the initial tear, the direction and extent of the dissection flap is unpredictable, possibly propagating proximally or distally. One consequence of a dissection flap is the occurrence of organ malperfusion by occlusion of the origin of the branch vessel. The 2 types of malperfusion in TBAD are static and dynamic, with the latter being the more common mechanism. Thoracic endovascular aortic repair (TEVAR) has demonstrated its high safety and efficacy when used for TBAD and subsequent malperfusion. AIMS: This original study specifically examines patients diagnosed with acute TBAD and treated with TEVAR at a single vascular unit, focusing on those presenting with organ malperfusion. METHODS: Over 16 years, 28 TBAD patients were admitted to a single center and treated using TEVAR. After clinical examination, all patients underwent computed tomography of the thorax and abdomen/pelvis to confirm the diagnosis and classify the extent of the dissection proximally and distally. Once diagnosed, patients were transferred to the high dependency unit and started on blood pressure medication. Subsequent computed tomography scans were performed to classify patients, after which TEVAR was performed. RESULTS: Twenty five patients underwent TEVAR for TBAD, of which 8 (32%) had symptoms of organ malperfusion. The majority of cases presented with hypertension (89%), describing a sudden onset of upper/midthoracic pain. The origin of the left subclavian artery was occluded in 14 (56%) patients with 9 (64%) needing an extra-anatomical bypass. There was only a single mortality due to a posterior circulation stroke 2 days after TEVAR. Median (range) length of coverage of thoracic aorta by the stent-graft was 33 (15-35) cm. The true lumen (TL) perfused the celiac artery in 6/8 malperfusion patients, superior mesenteric artery in 7/8, right renal artery in 6/8, and, conversely, left renal artery in only 2/8. CONCLUSIONS: Complicated TBADs behave in an unpredictable manner as it seems the propagating intimal flap invariably maintains vital organ perfusion via the TL. Maintenance of abdominal vessels perfusion from the TL following TEVAR is vital to ensuring optimal results.

A narrative review of the surgical management of Paget-Schroetter syndrome: case series and long-term follow-up.

Background and Objective: Paget-Schroetter syndrome (PSS) is an uncommon disorder which causes thrombosis of the subclavian vein (SV). This is due to compression of the SV by the surrounding anatomical structures. The optimal management of PSS remains subject to debate, with endovascular intervention and open surgical decompression being favoured current options. This review article evaluates both approaches to the management of PSS, while also presenting a case series with long-term follow-up of patients that underwent open surgical intervention for PSS. Methods: The clinical outcomes of PSS patients undergoing different 4 surgical approaches to perform surgical decompression are included. A literature review, across publications from PubMed, Embase, and Web of Science, was conducted with specific criteria to facilitate evaluation of both open surgical and endovascular approaches to the management of PSS. Key Content and Findings: Evaluation of data from the included case series and available literature suggests that endovascular thrombolytic devices offer better clinical results, however, SV decompression is still required for successful resolution. Conclusions: An approach to PSS encompassing endovascular intervention followed by surgical anatomical decompression may provide optimal outcomes as both intrinsic lesions and extrinsic compression of the SV is treated. However, further prospective investigation into this field is warranted.

Correlation of coagulopathy and frozen elephant trunk use in aortic arch surgery: A systematic review and meta-analysis.

BACKGROUND: The advent of frozen elephant trunk (FET) for reconstruction of elective and nonelective aortic arch surgery has augmented the treatment of complex aortic pathologies in a single-stage operation. To date, no studies have been focused on the prevalence and predictors of coagulopathy potentiated by FET procedure. METHODS: In a systematic review, we searched databases up to June 2020 to find studies reporting coagulopathy complications after FET procedure. A proportional meta-analysis was carried out using STATA software (StataCorp). RESULTS: A total of 46 studies consisting of 6313 patients were eligible. The pooled estimation of reoperation for postoperative bleeding was 7% (95% confidence interval [CI:] 5-8; I2 = 84.73%; reported by 39 studies including 4796 patients). The mean volume of transfused packed blood cells and fresh frozen plasma was 1677 ml (95% CI: 1066.4-2287.6) and 1016.5 ml (95% CI: 450.7-1582.3). The subgroup by the stent type showed a decrease in the heterogeneity (I2 = 0.01%, I2 = 53.95%, I2 = 0.01%, and I2 = 54.41% for Thoraflex® Hybrid, E-vita®, Frozenix®, and Cronus®, respectively). The subgroup by the chronicity of operation resulted in less heterogeneity among patients undergoing elective compared with nonelective operation (I2 = 29.22% vs. I2 = 80.56% in nonelective). Meta-regression analysis showed that age and male gender significantly impacted on the reoperation for postoperative bleeding. CONCLUSIONS: The FET procedure for arch replacement is associated with coagulopathy complications and the transfusion of blood products. Male, age, and selective choice of FET use were found to be the heterogeneity sources of reoperation for postoperative bleeding.