Endovascular Management of Thoracic Dissections

Clinical Characteristics and Risk Factors of Noninfectious Fever after Thoracic Endovascular Aortic Repair of Acute Type B Aortic Dissection

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) is gradually becoming a first-line treatment of complicated acute type B aortic dissection (ATBAD). Interestingly, according to years of experience in the treatment of ATBAD, we found that patients with ATBAD often had unexplained noninfectious fever after TEVAR. This study aims to explore its clinical characteristics and independent risk factors.

METHODS

From January 2016 to September 2021, 211 consecutive patients treated electively by TEVAR for ATBAD were included. The entry tears in all patients originated in the distal to the left subclavian artery (LSA). All patients were diagnosed with ATBAD for the first time. The definition of fever in this study was that the body temperature of patients after TEVAR exceeds 38°C.

RESULTS

A total of 211 patients (53.62 ± 11.34 years, 81% men) were included in the analysis. To compare patients who did and did not have post-TEVAR fever, they were respectively classified as the fever group and the nonfever group. Fever was diagnosed in 115 (55%) patients. Preoperatively, statistical differences were recorded in age (P = 0.023) and red blood cell (P = 0.037). Age <60 years [odds ratio (OR) 2.194, 95% confidence interval (CI) 1.147-4.196, P = 0.018] and duration of the operation >3 hr (OR 3.586, 95% CI 1.133-11.350, P = 0.03) were positively associated with fever. In the comparison of preoperative and postoperative experimental data, the changes in white blood cell (P = 0.046) and platelet (P = 0.007) of the 2 groups were significantly different. Hospital stay (P = 0.009) and postoperative hospital stay (P < 0.001) in the fever group were significantly prolonged. There was no difference in survival in the mid- and long-term follow-up between the 2 groups.

CONCLUSIONS

Noninfectious fever occurs in more than half of the patients after TEVAR (115/211, 54.5%). Patients in the fever group are younger. Age <60 years and duration of the operation >3 hr are independent risk factors for noninfectious fever in patients with ATBAD after TEVAR fever. Noninfectious fever after TEVAR may lead to prolonged hospital stay. However, it did not affect mid- and long-term prognosis.

Thoracic endovascular aortic repair of highly tapered type B aortic dissection with proximal tapered stent grafts and distal restrictive stent grafts

OBJECTIVES

This study evaluated aortic remodeling in highly tapered type B aortic dissection (TBAD) patients who underwent thoracic endovascular aortic repair (TEVAR) with a proximal tapered stent graft plus a distal restrictive stent graft to maximize thoracic coverage while avoiding distal excessive oversizing.

METHODS

Thirty-four patients presenting with highly tapered TABD were randomized to restricted TEVAR (r-TEVAR) and standard TEVAR groups. Highly tapered TBAD was defined as the maximal diameter of the true lumen at proximal and distal thoracic aorta landing zone tapers greater than 8 mm or taper ratio greater than 20%. Patients in the r-TEVAR group underwent proximal tapered stent grafts plus distal restrictive stent grafts to match the taper ratio of the descending thoracic aorta (DTA) and extend the length of stent coverage. Patients in the standard TEVAR group underwent proximal tapered stent grafts implantation without distal restrictive stent grafts. Aortic remodeling was estimated by computed tomography angiography (CTA) during the follow-up.

RESULTS

In total, 16 patients underwent r-TEVAR, and 18 patients underwent standard TEVAR. The taper ratio of the stent graft matched the DTA in the r-TEVAR group (24.7±3.4% vs. 27.3±4.2%, P=0.068) but did not match that in the standard TEVAR group (13.5±3.3% vs. 30.5±9.6%, P<0.001). The length of stent graft coverage in the r-TEVAR group was longer than that in the standard TEVAR group (220.4±21.1 mm vs. 175.3±17.8 mm, P<0.001). Compared with the standard TEVAR group, the r-TEVAR group had better complete remodeling of the DTA at 6 months (40% vs. 5.6%, P=0.03), 12 months (60% vs. 16.7%, P=0.027) and 24 months (78.6% vs. 41.2%, P=0.036) after the operation. There was no difference in the cumulative survival rate between the r-TEVAR and standard TEVAR groups (P=0.166).

CONCLUSIONS

r-TEVAR with overlapping proximal tapered stent grafts and distal restrictive stent grafts can match the taper of highly tapered TABD, extend the length of stent graft coverage, and lead to better remodeling of the DTA than standard TEVAR.

Biomechanical Analysis of Cadaveric Thoracic Aorta Zones: The Isthmus is the Weakest Region

BACKGROUND

The thoracic aorta is a site of multiple pathological processes, such as aneurysms and dissections. When considering the development of endovascular devices, this vessel has been extensively manipulated because of aortic diseases, as well as to serve as a route for procedures involving the head and neck vessels. Therefore, the aim of the present study was to obtain biomechanical experimental information about the strength and deformability of this vessel.

MATERIALS AND METHODS

Thirty-one thoracic aorta specimens were harvested during the autopsy procedure. They were carefully dissected and transversally sectioned according to Criado's aortic arch map landing zones (0 to 4). The supra-aortic trunks were removed, and the aortic rings were opened in their convexity, which resulted in flat tissue segments. Four millimeter-wide strips were prepared from each zone after which they were attached to a clip system connected to the INSTRON SPEC 2200 device, which was responsible for pulling the fragment up to its rupture during the uniaxial tension test. The INSPEC software was used to coordinate the test, and data management was conducted via the SERIES IX software. The biomechanical variables that were measured included failure stress, failure tension, and failure strain.

RESULTS

When comparing the five segments from all 31 aortas, three different strength levels were observed. Zones 0 and 1 exhibited the highest failure stress and failure tension values, followed by Zones 2 and 4. Zone 3 (aortic isthmus) was the weakest segment that was tested when compared to the stress and tension of Zones 0 and 1 (P < 0.001), the stress and tension of Zone 2 (P = 0.005 and P = 0.002, respectively) and the stress and tension of Zone 4 (P = 0.023 and P = 0.006, respectively). Among donors > 65 years-old, women presented significantly weaker descending aortas than men in regards to stress (P = 0.049) and tension (P = 0.014). Among male donors, the elderly donors presented significantly stiffer aortic walls and weaker ascending (P = 0.029 for stress) and descending (P = 0.004 for stress; P = 0.031 for tension) aortas than younger men.

CONCLUSIONS

Uniaxial tensile strength tests revealed that the thoracic aorta is a very heterogeneous vessel. Isthmus frailty may add to the understanding of the pathophysiology of some aortic diseases that commonly compromise this region. The lower strength that was verifiedin some aortic segments from elderly donors may contribute to the genesis of some thoracic aorta diseases among that group of donors. These data can contribute to the development of new endovascular devices that are specifically designed for this vessel.

Influence of thoracic endovascular aortic repair on true lumen helical morphology for Stanford type B dissections

OBJECTIVE

Thoracic endovascular aortic repair (TEVAR) can change the morphology of the flow lumen in aortic dissections, which may affect aortic hemodynamics and function. This study characterizes how the helical morphology of the true lumen in type B aortic dissections is altered by TEVAR.

METHODS

Patients with type B aortic dissection who underwent computed tomography angiography before and after TEVAR were retrospectively reviewed. Images were used to construct three-dimensional stereolithographic surface models of the true lumen and whole aorta using custom software. Stereolithographic models were segmented and co-registered to determine helical morphology of the true lumen with respect to the whole aorta. The true lumen region covered by the endograft was defined based on fiducial markers before and after TEVAR. The helical angle, average helical twist, peak helical twist, and cross-sectional eccentricity, area, and circumference were quantified in this region for pre- and post-TEVAR geometries.

RESULTS

Sixteen patients (61.3 ± 8.0 years; 12.5% female) were treated successfully for type B dissection (5 acute and 11 chronic) with TEVAR and scans before and after TEVAR were retrospectively obtained (follow-up interval 52 ± 91 days). From before to after TEVAR, the true lumen helical angle (-70.0 ± 71.1 to -64.9 ± 75.4°; P = .782), average helical twist (-4.1 ± 4.0 to -3.7 ± 3.8°/cm; P = .674), and peak helical twist (-13.2 ± 15.2 to -15.4 ± 14.2°/cm; P = .629) did not change. However, the true lumen helical radius (1.4 ± 0.5 to 1.0 ± 0.6 cm; P < .05) and eccentricity (0.9 ± 0.1 to 0.7 ± 0.1; P < .05) decreased, and the cross-sectional area (3.0 ± 1.1 to 5.0 ± 2.0 cm²; P < .05) and circumference (7.1 ± 1.0 to 8.0 ± 1.4 cm; P < .05) increased significantly from before to after TEVAR. The distinct bimodal distribution of chiral and achiral native dissections disappeared after TEVAR, and subgroup analyses showed that the true lumen circumference of acute dissections increased with TEVAR, although it did not for chronic dissections.

CONCLUSIONS

The unchanged helical angle and average and peak helical twists as a result of TEVAR suggest that the angular positions of the true lumen are constrained and that the endografts were helically conformable in the angular direction. The decrease of helical radius indicated a straightening of the corkscrew shape of the true lumen, and in combination with more circular and expanded lumen cross-sections, TEVAR produced luminal morphology that theoretically allows for lower flow resistance through the endografted portion. The impact of TEVAR on dissection flow lumen morphology and the interaction between endografts and aortic tissue can provide insight for improving device design, implantation technique, and long-term clinical outcomes.

A Parametric Analysis of Endovascular Stent Geometry Manipulation On Radial Force Performance

Stents were manufactured to investigate the impact of altering stent design characteristics (leg length, bend angle, bend radius, wire diameter) on radial force generation. Results from this design parameter study showed that leg length, bend angle and wire diameter have a statistically significant impact on radial force generation, while lesser changes in bend radius did not (1.00mm vs. the original 0.794mm [1/32in]). However a larger variation of this parameter (1.588mm [1/16in]) was statistically significant. Results gathered for all parameters were used in the creation of a prototypal software. Using input values of patient specific arterial diameter and compliance, as well as stent design characteristic dimensions, this program has been developed to predict stent radial force at varying levels of expansion.

Management of acute type B aortic dissection with malperfusion via endovascular fenestration/stenting

OBJECTIVE

The study objective was to evaluate the management of malperfusion in acute type B aortic dissection with endovascular fenestration/stenting.

METHODS

From 1996 to 2018, 182 patients with an acute type B aortic dissection underwent fenestration/stenting for suspected malperfusion based on imaging, clinical manifestations, and laboratory findings. Data were obtained from medical record review and the National Death Index database.

RESULTS

The median age of patients was 55 years. Signs of malperfusion included abdominal pain (61%), lower-extremity weakness (27%), nonpalpable lower-extremity pulses (24%), and abnormal lactate, creatinine, liver enzymes, and creatine kinase levels. Confirmed hemodynamically significant malperfusion affected the spinal cord (2.7%), celiac (24%), superior mesenteric (40%), renal (51%), and iliofemoral (43%) arterial distributions. Of the 182 patients, 99 (54%) underwent aortic fenestration/stenting, 108 (59%) had 1 or multi-branch vessel fenestration/stenting, 5 (2.7%) had concomitant thoracic endovascular aortic repair, 17 (9.3%) had additional thrombolysis or thromboembolectomy, and 48 (26%) received no intervention. After fenestration/stenting, 24 patients (13%) required additional procedures for necrotic bowel or limb and 9 patients (4.9%) had subsequent aortic repair (thoracic endovascular aortic repair, open repair) before discharge. The new-onset paraplegia was 0%. The in-hospital mortality was 7.7% over 20+ years and 0% in the last 8 years. The 5- and 10-year survivals were 72% and 49%, respectively. The significant risk factors for late mortality were age and acute paralysis (hazard ratio, 3.5; both P < .0001). Given death as a competing factor, the 5- and 10-year cumulative incidence of reintervention was 21% and 31% for distal aortic pathology, respectively.

CONCLUSIONS

Patients with acute type B aortic dissection with malperfusion can be managed with endovascular fenestration/stenting with excellent short- and long-term outcomes. This approach is particularly helpful to patients with static malperfusion of aortic branch vessels.

Consistency of Proximal-to-Distal Tapering of Descending Thoracic Aortic Diameter: Quantification Using a Novel Computer Tomography-based Assessment

BACKGROUND

Successful endovascular repair of thoracic aorta for type B aortic dissection requires correct stent-graft sizing, particularly of distal landing zone which is mainly based on operator experience. The present study aimed to quantitatively define proximal-to-distal tapering of descending thoracic aortic diameter and its consistency.

METHODS

The novel parameter HDP (Hundred times Distance accounts for Percentage)-measured as distance from the distal end of the left subclavian artery to each level along the aortic central line/length from the distal end of the left subclavian artery to the proximal end of the celiac artery along the aortic central line × 100-was calculated per 1% unit of descending thoracic aorta based on 3-mensio software-derived measurements from 281 consecutive individuals who had undergone enhanced chest computer tomography scanning. Association between HDP and maximal diameter of descending thoracic aorta was assessed by using the generalized additive mixed model with smoothing function and threshold saturation effect analyses with generalized estimating equations. Nonadjusted and adjusted models were performed to illuminate its consistency.

RESULTS

Three inflection levels (HDPs of 15.01, 36.63, and 77.74) were identified which allowed to divide the descending thoracic aorta into 4 segments. The taper was consistent before and after adjusting for age, sex, height, body mass index, hypertension, smoking habits, hyperlipidemia, and diabetes. Although 1% unit of descending thoracic aorta decreases, the maximal diameter reduces to 0.007 mm (-0.025, 0.010; P = 0.414) in the segment with HDP <15.01, to 0.151 mm (-0.158, -0.145; P < 0.001) in the segment with 15.01 ≤ HDP < 36.63, to 0.038 mm (-0.040, -0.036; P < 0.001) in the segment with 36.63 < HDP ≤ 77.74; and to 0.026 mm (-0.049, -0.002; P = 0.035) in the segment with HDP > 77.74, respectively.

CONCLUSIONS

The maximal diameter of descending thoracic aorta decreases gradually and consistently among individuals free of aortic diseases.

Endovascular management of ruptured abdominal aortic aneurysms and acute aortic dissections

The management of vascular emergencies is dependent on rapid identification and confirmation of the diagnosis with concurrent patient stabilization prior to immediate transfer to the operating suite. A variety of technological advances in diagnostic imaging as well as the advent of minimally invasive endovascular interventions have shifted the contemporary treatment algorithms of such pathologies. This review provides a comprehensive discussion on the current state and future trends in the management of ruptured abdominal aortic aneurysms as well as acute aortic dissections.

Management of Type B Aortic Dissections: Treatment of Acute Dissections and Acute Complications from Chronic Dissections

Aortic dissection is one of the most catastrophic vascular challenges faced by interventionalists, often misdiagnosed and frequently associated with devastating consequences. Stanford type B aortic dissections affects the descending thoracic aorta without any involvement of the ascending aorta. Dissections associated with refractory pain, rapid aneurysm formation, malperfusion syndromes, rupture, or impending rupture are categorized as complicated and distinct from initially uncomplicated type B dissections without the aforementioned complications. Traditionally, uncomplicated type B dissection is managed medically whereas complicated type B dissection requires intervention to limit mortality. Over the last two decades, thoracic endovascular aortic repair (TEVAR) has emerged as an alternative to open surgical repair for treatment of complicated type B dissection. Various societal guidelines now unanimously propose TEVAR as the treatment of choice for management of complicated disease based on its relatively low morbidity and mortality compared to open surgical outcomes. As the consensually acknowledged standard of care for management of patients with complicated lesions, TEVAR is currently being considered for select patients with initially uncomplicated dissection to mitigate the risks of mid and late-term disease progression and aortic-related mortality. This article describes the decision-making treatment algorithm for management of type B aortic dissection. It also provides a comprehensive review of the indications and procedural recommendations for performing TEVAR based on current evidence in the literature. Additionally, the article guides the readers through step-by-step practical considerations, from choosing the optimal graft to insuring its ideal deployment in type B dissection, as well as providing advice on how to handle a variety of procedure-related complications.

Reverse extra-anatomic aortic arch debranching procedure allowing thoracic endovascular aortic repair of a chronic ascending aortic aneurysm

A 79-year-old woman was admitted with a large chronic dissecting ascending aortic aneurysm starting 5 mm distal to the ostia of the left coronary artery and ending immediately proximal to the innominate artery. A reverse extra-anatomic aortic arch debranching procedure was performed. During the same operative time, through a transapical approach, a thoracic stent graft was deployed with the proximal landing zone just distal to the coronary ostia and the distal landing zone excluding the origin of the left common carotid artery. The postoperative course was uneventful. Computed tomography at 12 months documented patent extra-anatomic aortic arch debranching and no evidence of endoleak.

Dissecção aórtica de tipo B de Stanford: relato de caso e revisão de literatura

O complexo tratamento de dissecção da aorta ainda apresenta controvérsias devido à gravidade do caso e à necessidade de individualização da terapêutica. A gravidade relaciona-se ao difícil diagnóstico pelas queixas inespecíficas e pelas graves complicações inerentes à evolução da doença (ruptura aórtica, síndrome de má perfusão, dissecção retrógrada, dor ou hipertensão refratária). Este relato apresenta um homem de 61 anos, tabagista e hipertenso mal controlado, que evoluiu para dissecção aórtica de tipo B de Stanford. Foi abordado através de técnica endovascular com uso de endoprótese com stent para tratamento do caso após falha do tratamento medicamentoso. O tratamento endovascular mostrou-se uma ferramenta eficaz para o tratamento definitivo, com boa taxa de sobrevida ao final do primeiro ano após o procedimento.

Spot Stenting of Supra-aortic Branch Vessels for Residual Type A Dissection

The purpose of this report was to describe the exclusion of the false lumen in a residual type A aortic dissection (TAAD) by the deployment of 2 covered stents: one in the right common carotid artery (RCCA) and one in the left subclavian artery (LSA). A 77-year-old female, already treated with ascending aorta replacement for acute TAAD, was referred to our center for a 97-mm post-dissection arch aneurysm. A computed tomography angiography (CTA) showed false lumen patency by reperfusion from secondary tears located at the level of RCCA and LSA. No primary aortic tear was noted. Under local anesthesia and by transfemoral percutaneous approach, the tears at the level of RCCA and LSA were covered by a 9-mm Viabahn stent graft (Gore, Flagstaff, AZ), and a 10-mm V-12 stent graft (Maquet, Rastatt, Germany), respectively. The false lumen was finally occluded by the deployment of a 6-mm vascular plug at the level of LSA re-entry tear, by left transbrachial puncture. The procedure was completed uneventfully. Twelve-month CTA showed exclusion of the false lumen, patency of all supra aortic trunks, and initial shrinkage of the aneurysm. Spot stenting of secondary re-entry tears, already described for visceral branches, seems to be safe and effective also for supra-aortic trunks in selected patients.

CT of suspected thoracic acute aortic injury in the emergency department: is routine abdominopelvic imaging worth the additional collective radiation dose?

This study aimed to determine the incidence of non-traumatic acute aortic injury (AAI) extending from the chest into the abdomen or pelvis in emergency department (ED) patients with acute aortic syndrome (AAS), to estimate the effective dose of the abdominopelvic portion of these CT exams, and to compare the number needed to screen (NNS) with the collective population radiation dose of imaging those stations. All patients (n = 238) presenting to the ED with AAS between March 2014 and June 2015 who were imaged per CT AAI protocol (noncontrast and contrast-enhanced CT angiography of the chest, abdomen, and pelvis) were retrospectively identified in this IRB-approved HIPAA-compliant study. The Stanford classification for positive cases of AAI was further subclassified based on chest, abdominal, or pelvic involvement. The dose length product (DLP) of each exam was used to estimate the dose of the abdominal and pelvic stations and the collective effective dose for the population. There were five cases of aortic dissection (AD) and two of intramural hematoma (IMH), with an AAI incidence of 2.9/100. Three cases of AAI were confined to the chest. Two cases of AAI were confined to the chest and abdomen, and two cases involved the chest, abdomen, and pelvis. There was only one case of AAI involving the ascending aorta that extended into the abdomen or pelvis. The number needed to screen to identify (a) AAI extending from the chest into the abdomen or pelvis was 59.5 and (b) Stanford A AAI extending into the abdomen or pelvis was 238. The estimated mean effective dose for the abdominopelvic stations were unenhanced abdomen 2.3 mSv, unenhanced pelvis 3.3 mSv, abdominal CTA 2.5 mSv, and pelvic CTA 3.6 mSv. The collective effective doses to the abdomen and pelvis with unenhanced CT and CTA in 59.5 patients and 238 patients were 761.6 and 3046.4 mSv, respectively. While the estimated mean effective dose for imaging of the abdominopelvic stations are low, the collective effective dose should also be considered. It may be beneficial to modify or omit routine unenhanced CT and/or CTA of the abdomen/pelvis in this patient population in the absence of abdominal symptoms, and image the abdomen and pelvis in positive thoracic cases only.

Total aortic repair: the new paradigm in the treatment of acute type A aortic dissection

The surgical management of acute type A aortic dissection (ATAAD) is in a period of rapid evolution. Understanding the complex physiology and anatomy of both acute and chronic dissection has been enhanced by the ready availability of state of the art imaging techniques. Technical advances in the intraoperative monitoring of organ perfusion, together with adjuncts to limit organ injury and increasing sophistication in open and endovascular surgery have led to a major reduction in both perioperative morbidity and mortality. In many centers, there has been a transition in mindset and surgical approach away from a purely central aortic operation focusing on the ascending aorta and a 'live to fight another day' philosophy. The current more global perspective recognizes the importance of aortic valve function, malperfusion, false lumen (FL) patency and the potential for future complex aneurysm development. The time is now right to transition into the next phase of sophistication in the management of ATAAD with the aim of achieving not only a safe acute operation, but to either entirely prevent chronic complications or to greatly simplify their management by the creation of an anatomical situation that facilitates future endovascular intervention in place of complex re-do surgery. We present our view on the evolution of surgery for ATAAD leading to our current technique of Branch First Arch replacement and Total Aortic Repair, which not only provides a safe immediate operation, but also offers the hope of a simplified future management if not a total cure for the pathology.

Thoracic endovascular aortic repair for complicated chronic type B aortic dissection in a patient on hemodialysis with recurrent ischemic colitis

We present a successful case of thoracic endovascular aortic repair (TEVAR) for chronic Stanford type B aortic dissection (B-AD) with recurrent ischemic colitis. The patient was a 56-year-old woman with abdominal pain as the main complaint who had two operations previously: the total arch replacement 8 years ago and the Bentall 7 years ago for acute Stanford type A aortic dissection. Her abdominal pain worsened as her blood pressure became low during her hemodialysis treatment. An enhanced computed tomography scan was performed on the patient and showed chronic B-AD that occurred from the distal anastomotic part of the total arch graft to the bilateral common iliac arteries. The celiac artery and superior mesenteric artery (SMA) arose from the true lumen, and these were compressed by the expanded false lumen. Her complicated chronic B-AD was treated with the Zenith Dissection Endovascular System, and its procedure was performed as her proximal entry tear was covered by a proximal tapered Zenith TX2 stent graft, supplemented by a noncovered aortic stent extending across both renal arteries, the SMA, and the celiac artery. Seven days after this operation, enhanced computed tomography showed that the patient's true lumen was expanded and her blood flow to the true lumen and SMA was improved. On the other hand, her false lumen tended to be thrombosed. Consequently, she was discharged 10 days after the operation without any postoperative complications as she had no abdominal complaints even though she underwent hemodialysis three times per week after the operation. We believe that TEVAR supplemented by a noncovered aortic stent is an effective treatment, even for highly chronic B-AD in dialysis patients.

Endovascular repair of Stanford B aortic dissection using two stent grafts with different sizes

OBJECTIVE

The objective of this study was to introduce a novel strategy for thoracic endovascular aortic repair of Stanford B aortic dissection using two-stent graft implantation (TSI), in which the proximal stent and distal stent with different sizes are sequentially deployed, and to summarize our experience with this technique.

METHODS

A retrospective study was conducted of 72 consecutive patients (61 men; mean age, 55 ± 7 years; range, 41-67 years) with Stanford type B aortic dissection who underwent TSI treatment between January 2012 and May 2013. Among all patients, 43 (59.7%) involved the infrarenal aorta and 29 (40.3%) involved the whole thoracic and abdominal aorta; mean aortic involvement length was 226 ± 13 mm (range, 182-312 mm). Eight cases were for acute dissection (within 2 weeks from onset of symptoms), 11 cases were for chronic dissection (>3 months after initial dissection), and 53 cases were for subacute dissection (between 2 weeks and 3 months). Twenty-two cases (30.6%) were uncomplicated type and 50 cases (69.4%) were complicated type. Follow-up was performed postoperatively at 1 month, 6 months, and yearly thereafter. Technique success, aorta morphology, and procedure-related complications were evaluated.

RESULTS

Technical success was achieved in 100%; 72 pairs of stent grafts (144 thoracic stent grafts) and 10 left subclavian artery chimney stents were used. The mean aortic length coverage by the stent grafts was 197.6 ± 20.3 mm, and mean taper diameter span was 7.5 ± 1.8 mm. All patients were followed up from 6 to 16 months (mean, 10 ± 4 months); 95.8% (69 of 72) had a thrombosed false lumen in the aortic coverage, and the true lumen expanded on average 57% ± 11% (23%-100%). No significant changes were found in aortic diameters of the proximal and distal ends of the two stent grafts and the angles between centerlines of the distal end of the stent and the aorta during follow-up. Procedure-related complications included transient paraplegia (coverage of the left subclavian artery without revascularization and extensive coverage of aorta >220 mm) due to acute spinal cord ischemia (n = 1) and malapposition of the distal stent (primary tear closed, true lumen expansion led to oversize rate insufficient in distal stent diameter; n = 1). No death or malperfusion complications were observed during the perioperative period and follow-up.

CONCLUSIONS

Short-term outcomes showed TSI to be a flexible and effective approach to accurately repair Stanford B aortic dissection that could potentially address the limitations of currently available stent grafts. Further prospective clinical studies are warranted to evaluate its long-term efficacy.

Endovascular management of rupture in acute type B aortic dissections

OBJECTIVE

Reports of thoracic endovascular aortic repair (TEVAR) for complicated acute type B aortic dissection (ABAD) bring together a large range of clinical presentations. With a 30 day mortality of 50% when managed with open surgery, rupture is the most devastating complication of ABAD. This study investigated the outcome of TEVAR for ABAD complicated by rupture (r-ABAD) to assess the results of this particularly critical subgroup.

METHODS

A review of consecutive TEVAR for r-ABAD in two tertiary referral centers was performed using a prospectively maintained database.

RESULTS

Between 2000 and 2013, 24 patients (mean age 71 years; 14 males) underwent TEVAR for r-ABAD. Sixteen (67%) were in shock (Systolic blood pressure <80 mmHg) before surgery. Seven patients had coverage of the left subclavian artery, of whom four had partial arch debranching procedures via cervical access concomitant with TEVAR. Median length of aortic coverage was 150 mm, median proximal oversizing was 13.3% (range 6.2-33.3%). Technical success was achieved in 100%. There were four in hospital deaths (16%). Two patients (8%) had paraplegia, but neither stroke nor renal insufficiency requiring dialysis occurred. During a mean follow up of 28 months, there was one aortic dissection related death and eight patients (40% of the surviving patients) required re-intervention. All re-interventions were managed endovascularly. At last follow up CT scan, eight patients (40%) had complete remodeling of the aortic wall.

CONCLUSION

With 16% in hospital mortality and 8% early major complications, this study confirms the feasibility of TEVAR for r-ABAD with a lower peri-operative morbidity and mortality rate compared with open surgery. Given the high rate of re-intervention, close follow up is required in surviving patients.

The role of multidetector-row CT in the diagnosis, classification and management of acute aortic syndrome

The term "acute aortic syndrome" (AAS) encompasses several non-traumatic life-threatening pathologies of the thoracic aorta presenting in patients with a similar clinical profile. These include aortic dissection, intramural haematoma and penetrating atherosclerotic ulcers. These different pathological entities can be indistinguishable on clinical grounds alone and may be confused with other causes of chest pain, including myocardial infarction. Multidetector-row CT (MDCT) is the current modality of choice for imaging AAS with a sensitivity and specificity approaching 100%. Early diagnosis and accurate radiological classification is associated with improved clinical outcomes in AAS. We review the characteristic radiological features of the different pathologies that encompass AAS and highlight the vital role of MDCT in determining the management of these life-threatening conditions.

Case report and review of the literatureTotal Endovascular Repair of Acute Ascending Aortic Rupture

Thoracic aortic endografting has been successfully implemented to treat aneurysmal disease of the distal aortic arch and descending thoracic aorta. Although there are reports of ascending aortic endovascular interventions, the total endovascular repair of a ruptured ascending aorta secondary to a Type A dissection has not been described. We report the case of a 77-year-old patient who presented with a ruptured ascending aortic aneurysm secondary to degeneration of a Stanford type A aortic dissection. His surgical history was significant for orthotropic heart transplant 19 years prior. The dissection, aneurysm, and rupture occurred in the native aorta distal to the ascending aortic suture line. At presentation, he was hemodynamically unstable with a right hemothorax. We placed 3 Medtronic Talent Thoracic Stent Graft devices (Medtronic Inc, Minneapolis, MN) across the suture line in the ascending aorta, excluding the rupture. The patient survived and has been followed to 25 months.

A young patient with massive haematemesis

Aortoesophageal fistula (AEF) is a rare and life-threatening cause of gastrointestinal haemorrhage which requires emergency surgical intervention. We report a case of aortoesophageal fistula due to previous endovascular stent grafting to the ascending thoracic aorta after previous traumatic injury. The patient presented with catastrophic haematemesis which was managed by repeated deployment of endovascular stent graft and aortic bypass surgery; however, the patient ultimately died due to massive haemoptysis.

Endovascular management of acute aortic syndromes

The term "acute aortic syndrome" (AAS) refers to a spectrum of life-threatening thoracic aortic pathologies including intramural hematoma, penetrating atherosclerotic ulcer, and aortic dissection. Clinically, patients often present with characteristic aortic pain. AAS often leads to aortic rupture. Therefore, recognition of this condition, its prompt diagnosis, and timely treatment is crucial to obtain clinical success and improved overall survival. The management of AAS, however, remains a therapeutic challenge. Endovascular strategies have gained wide acceptance and now represent a minimally invasive alternative to traditional open surgery. Several studies have shown endovascular repair of varying thoracic aortic pathologies to be technically feasible with fewer complications than open surgery. In this review, the authors discuss AAS pathology and its management, with particular attention to the current role of endovascular aortic repair and its treatment.

[Treatment of thoracic aortic disease using endovascular stent-grafts: from therapeutic indications to possible complications]

Thoracic endovascular aortic repair (TEVAR) is a minimally invasive technique which is increasingly used in different thoracic aortic pathologies such as aortic aneurysm, complicated type B aortic dissection, aortic trauma, intramural hematoma and penetrating aortic ulcer. In this paper we discuss the main indications for endovascular stent-grafts in the treatment of thoracic aortic disease, based on three cases in which this procedure was used for three different conditions: degenerative aneurysm, complicated type B dissection and post-traumatic injury. These case reports add to the evidence that TEVAR is a safe and feasible therapeutic alternative in selected patients with thoracic aortic disease, improving aortic remodeling, with relatively low morbidity and mortality. The main complications and difficulties related to the procedure are also discussed.

Management of acute aortic syndromes

Acute aortic syndrome (AAS) is a modern term to describe interrelated emergency aortic conditions with similar clinical characteristics and challenges. These conditions include aortic dissection, intramural haematoma (IMH), and penetrating atherosclerotic ulcer (PAU and aortic rupture); trauma to the aorta with intimal laceration may also be considered. The common denominator of AAS is disruption of the media layer of the aorta with bleeding within IMH, along the aortic media resulting in separation of the layers of the aorta (dissection), or transmurally through the wall in the case of ruptured PAU or trauma. Population-based studies suggest that the incidence of acute dissection ranges from 2 to 3.5 cases per 100 000 person-years; hypertension and a variety of genetic disorders with altered connective tissues are the most prevalent risk conditions. Patients with AAS often present in a similar fashion, regardless of the underlying condition of dissection, IMH, PAU, or contained aortic rupture. Pain is the most commonly presenting symptom of acute aortic dissection and should prompt immediate attention including diagnostic imaging modalities (such as multislice computed tomography, transoesophageal ultrasound, or magnetic resonance imaging). Prognosis is clearly related to undelayed diagnosis and appropriate surgical repair in the case of proximal involvement of the aorta; affection of distal segments of the aorta may call for individualized therapeutic approaches favouring endovascular in the presence of malperfusion or imminent rupture, or medical management.