Endovascular stent-graft treatment of aortic dissection: determinants of post-interventional outcome

Fever Management after TEVAR in Patients with Aortic Dissection

BACKGROUND

Post-implantation syndrome (PIS) is characterised as a noninfectious continuous fever and a concomitant rise in inflammatory markers shortly after thoracic endovascular aortic repair (TEVAR). This current study aims to analyse the risk factors of PIS, postoperative major adverse cardiac events (MACE), and overall survival as well as the correlation between new-onset mural thrombus and the risk of developing PIS after TEVAR in patients with type B aortic dissection (TBAD). Patients were included who had a B dissection, both acute and chronic forms. In the acute form, both acutely complicated and uncomplicated patients were included in the study. A main point of our investigation is the postoperative fever management of PIS patients.

METHODS

A total of 90 patients with type B dissection underwent TEVAR in the University Hospital of Muenster between 2016 and 2020. The occurrence of PIS was defined as the presence of fever (> 38°C lasting longer than 24 hours in hospital) and leucocytosis (white blood cell count > 12000/µL). Patients with other possible reasons for fever and/or leucocytosis, such as a urinary tract infection (UTI), pneumonia, or sepsis, were excluded beforehand. Besides demographic and operation-related data, inflammatory markers and therapeutic measures were evaluated before and 5 days postoperatively. Computed tomography scans were examined to calculate the volume of preexistent and new-onset mural thrombus after TEVAR.

RESULTS

Of 90 patients, 40 patients were excluded because of recent infection or bypass surgery. Of the 50 patients included in the study, 10 patients developed post-implantation syndrome. Younger patients significantly more often developed PIS after TEVAR (52.2 ± 11.6 vs. 61.5 ± 13.6, p = 0.045). New-onset thrombus after TEVAR was significantly higher in PIS patients (61 cm³ vs. 12 cm³, p < 0.001) and PIS patients often received more medical examinations (investigation of X-ray, U status, and blood cultures). There was no significant difference in overall survival for 40 months and in the incidence of MACE.

CONCLUSIONS

PIS may be related to an increased rate of new-onset thrombus. A more robust conclusion is not justified according to our study. There is no difference in overall survival.

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.

Prognostic Value of the Systemic Immune Inflammation Index after Thoracic Endovascular Aortic Repair in Patients with Type B Aortic Dissection

The study aimed at investigating the association between postoperative inflammatory scores and aorta-related adverse events (AAEs) after thoracic endovascular aortic repair (TEVAR) for patients with type B aortic dissection (TBAD). This single-centre, retrospective cohort included all patients who underwent TEVAR for TBAD between November 2016 and November 2020 at a university hospital. The risk factors for AAEs were analyzed by Cox proportional hazards model regression. Prediction accuracy was assessed using the area under the receiver operating characteristic curves. This study included 186 patients with a mean age of 58.5 years and a median follow-up period of 26 months. A total of 68 patients developed AAEs. Age and postoperative systemic immune inflammation index (SII) (>2893) were associated with post-TEVAR AAEs (hazard ratio (HR) 1.03, p = 0.003; HR 1.88, p = 0.043, respectively). Increased postoperative SII and age are independent risk factors for AAE post-TEVAR in patients with TBAD.

A New Era of Diagnosis and Therapy in Acute Aortic Syndromes: The Mainz-Essen Experience (Part II)-Management and Outcomes

Over the years, the cardiovascular department of Johannes Gutenberg University in Mainz-West-German Heart Centre in Essen (Germany) designed and implemented the hybrid operating room (2003) along with advanced endovascular and surgical procedures, including the frozen elephant trunk technique. For the study purpose, the Mainz-Essen experience on acute aortic syndromes was summarized by considering original articles from single-center or multicenter studies performed at West German Heart Centre, Essen, Germany, or at the cardiovascular department of Johannes Gutenberg University, Mainz, Germany. We present the 35-year-long Mainz-Essen research, education, and patient management journey in creating an integrated multidisciplinary "Aortic Center" in the heart of Europe.

Dexmedetomidine reduces acute kidney injury after endovascular aortic repair of Stanford type B aortic dissection: A randomized, double-blind, placebo-controlled pilot study

STUDY OBJECTIVE

To determine the effect of dexmedetomidine on acute kidney injury (AKI) following endovascular aortic repair (EVAR) for Stanford type B aortic dissection (TBAD).

DESIGN

Randomized, double-blind, placebo-controlled, pilot study.

SETTING

University Hospital.

PATIENTS

102 TBAD patients undergoing EVAR procedures were enrolled. Patients with dissection involving aortic arch or renal artery were excluded.

INTERVENTIONS

Patients were randomly assigned, in a 1:1 ratio, to a dexmedetomidine group (intravenous dexmedetomidine 0.4 μg/kg/h immediately after anesthesia induction and 0.1 μg/kg/h after extubation, which was maintained until 24 h) or a normal saline control group.

MEASUREMENTS

The primary outcome was the incidence of AKI within the first two days after surgery, based on the Acute Kidney Injury Network (AKIN) criteria. The secondary outcomes included serum cystatin C and estimated glomerular filtration rate on postoperative days 1, 2, and 7, and in-hospital need for renal replacement therapy (RRT). Long-term outcomes included RRT and all-cause mortality.

MAIN RESULTS

Ninety-eight patients completed the study (dexmedetomidine, n = 48; control, n = 50). AKIN stage 1 AKI occurred in 3/48 (6.3%) patients receiving dexmedetomidine, compared with 11/50 (22%) patients receiving normal saline (odds ratio = 0.24, 95% CI: 0.07 to 0.89, P = 0.041). This difference remained significant after adjusting for baseline covariates (adjusted odds ratio = 0.21, 95% CI: 0.05 to 0.84; P = 0.028). Dexmedetomidine led to a lower serum cystatin C on postoperative day 1 (median [IQR] mg/L: 1.31 [1.02-1.72] vs. 1.58 [1.28-1.96]). There were no between-group differences in other secondary or long-term outcomes. During the follow-up (median = 28.4 months), 1 patient in the dexmedetomidine group and 3 patients in the control group required RRT.

CONCLUSIONS

Dexmedetomidine reduced the incidence of AKI in TBAD patients after EVAR procedures. The long-term benefits of dexmedetomidine in this patient population warrant further investigation.

TRIAL REGISTRATION

ChiCTR-IPR-15006372.

Thoracic endovascular aortic repair to treat uncomplicated Stanford type B aortic dissection: The surgeon's dilemma to preventing future complications

Uncomplicated type B aortic dissections have traditionally been managed non-operatively with aggressive blood pressure control. However, the best medical treatment is associated with a considerable risk of disease progression to complicated dissection or aneurysmal degeneration of the affected aortic segment. Thoracic endovascular aortic repair could prevent long-term complications but, because the dissected aorta is vulnerable, it is a high-risk procedure performed in asymptomatic patient. Therefore, endovascular treatment is not a solution for all patients and it should be performed only in the subgroup prone to developing progression of the disease and future complications. A number of studies have suggested several prognostic factors of early or late adverse events such as the patency of the false lumen in the follow-up, an initial aortic diameter ≥4 cm with a patent false lumen, an initial false lumen diameter ≥22 mm in the proximal descending aorta, visceral involvement and recurrent or refractory pain or hypertension. Partial false lumen thrombosis and a proximal entry tear size >10 mm have also been suggested to be associated with an increased rate of aortic growth. We need randomised trials focused on these prognostic factors to reach level 1, class A recommendation for the optimal timing of intervention. Meanwhile, we have to discuss with the patient the pro and cons of this prophylactic, low-invasive but high-risk treatment to personalise medical care and provide the optimal risk-to-benefit ratio.

Aortic remodelling after thoracic endovascular aortic repair for acute and subacute type B aortic dissection

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) in the current era has gained widespread acceptance as the modality of choice for the treatment of complicated aortic dissection (AD). However, reports on clinical results of TEVAR treatment of AD patients are mainly comparisons and analyses of results between patients in the acute and chronic phases, few reports have described the postoperative aortic remodelling of patients with subacute AD after TEVAR. The aim of this study was to investigate aortic remodelling after TEVAR in acute and subacute Stanford type B AD patients.

METHODS

The clinical data of 38 Stanford type B AD patients who received TEVAR treatment in our hospital between July 2012 and December 2017 were retrospectively analysed. The maximum diameters of the aorta, the mean diameters of the true lumens (TLs) and the false lumens (FLs) of the aorta in the dissection range before and after TEVAR treatment were measured. All diameters between different groups or in the same group before and after therapy were compared using nonparametric tests. Count data were examined using the χ² test.

RESULTS

The 38 patients were 31.0-82.0 years old with a mean age of 57.0±11.0 years, including 31 men and 7 women, with 22 patients in the acute phase and 16 patients in the subacute phase. Among the 38 patients included in this study, 7 (18.4%) patients had endoleaks after treatment. No perioperative deaths occurred. Analyses of computed tomography angiography measurement results showed that the baseline maximum diameters of the aorta, TLs and FLs before TEVAR between the acute and subacute groups were not significantly different (P=0.193, P=0.301 and P=0.067, respectively). After TEVAR treatment, the maximum diameters of the aorta and the diameters of the FLs were different between the two groups (P=0.005 and P=0.012), but the diameters of the TLs were not (P=0.069). The diameters of the TLs increased, and those of FLs decreased significantly in the acute and subacute groups after TEVAR (P<0.001, P<0.001, P<0.001 and P=0.007, respectively); the maximum diameters of the aorta decreased significantly in the acute group (P<0.001), but they did not change obviously in the subacute group (P=0.121).

CONCLUSIONS

TEVAR offers satisfactory results for the treatment of type B AD. Acute AD may be associated with better aortic remodelling compared to subacute AD after TEVAR.

Impact of Preoperative Anemia and Postoperative Hemoglobin Drop on the Incidence of Acute Kidney Injury and In-Hospital Mortality in Patients With Type B Acute Aortic Syndromes Undergoing Thoracic Endovascular Aortic Repair

BACKGROUND

The impact of preoperative anemia and postoperative hemoglobin (Hb) drop on the incidence of acute kidney injury (AKI) after thoracic endovascular aortic repair (TEVAR) for type B acute aortic syndromes (AAS) as well as their prognostic value is unknown.

METHODS

This retrospective study included 144 patients with type B AAS undergoing TEVAR at our center. Preoperative anemia was classified as no/mild (Hb ≥ 12.0 g/dL in men; ≥11.3 g/dL in women), moderate (Hb 10.80-11.99 g/dL in men; 10.23-11.29 g/dL in women), and severe (<10.80 g/dL in men; <10.23 g/dL in women). Postoperative Hb drop was classified as mild (<2 g/dL), moderate (2-4 g/dL), and severe (>4 g/dL). End points of the study were postoperative AKI and in-hospital mortality.

RESULTS

Postoperative AKI was higher in the severe and moderate anemia groups than the no/mild anemia group (63.2%, 52.0%, and 31.0%, respectively, P = .01). In-hospital mortality and AKI were higher in patients with severe postoperative Hb drop (40.9% and 86.4%) than patients with moderate (6.9% and 36.2%) and mild (4.7% and 25.0%) postoperative Hb drop (both P < .001). Postoperative Hb drop (odds ratio [OR]:1.67, P = .036), postoperative Hb levels (OR: 0.57, P = .025), and mesenteric ischemia (OR: 4.65, P = .044) were identified as independent predictors of in-hospital mortality. Preoperative Hb (OR: 0.26, P = .001), postoperative Hb drop (OR: 4.34, P < .001), contrast medium (OR: 1.82, P = .004), and diabetes mellitus (OR: 3.79, P = .001) were independent predictors of AKI. At follow-up, anemia and postoperative Hb drop were not associated with increased mortality.

CONCLUSION

Preoperative Hb and postoperative Hb drop were significant risk factors for AKI. Postoperative Hb drop and Hb levels predicted in-hospital mortality.

The new indication of TEVAR for uncomplicated type B aortic dissection

The classical therapeutic indication for type B aortic dissection is based on either medication or open surgery; medication therapy is recommended for relatively stable uncomplicated type B aortic dissection. With improvements in endovascular repair and the potential risk of disease progression, it is now necessary to evaluate the requirement for revision of the therapeutic choice of uncomplicated type B aortic dissection based on morphological features and time window. Data from 252 patients diagnosed as uncomplicated type B aortic dissection from 1992 to 2015 were analyzed retrospectively. Among these cases, 117 patients received medication therapy and 135 patients underwent endovascular repair. The 60-month survival rate in the endovascular group was higher than that in the medication group (92.3% vs 67.6%). According to the morphological evaluation, visceral artery involvement and false/true lumen ratios over 0.7 were strong risk factors for medical treatment alone. Increased surgical time and blood loss were found in patients treated in the chronic phase, compared with those who underwent endovascular repair within 14 days of the onset of symptoms. With improvements in aortic remodeling techniques, endovascular repair has been shown to improve long-term survival rates of patients with uncomplicated aortic dissection. Considering the potential risk of death, we recommend that patients with visceral artery involvement and a false/true lumen ratio over 0.7 should receive endovascular repair aggressively. Furthermore, delayed endovascular repair in the chronic phase does not improve the long-term outcome of uncomplicated type B aortic dissection.

Type B Aortic Dissection: A Review of Prognostic Factors and Meta-analysis of Treatment Options

According to international guidelines, stable patients with uncomplicated Type B aortic dissection (TBAD) should receive optimal medical treatment. Despite adequate antihypertensive therapy, the long-term prognosis of these patients is characterized by a significant aortic aneurysm formation in 25-30% within four years, and survival rates from 50 to 80% at five years and 30 to 60% at 10 years. In a prospective randomized trial, preemptive thoracic endovascular aortic repair (TEVAR) in patients with chronic uncomplicated TBAD was associated with an excess early mortality (due to periprocedural hazards), but the procedure showed its benefit in prevention of aortic-specific mortality at five years of follow-up. However, preemptive TEVAR may not be the treatment of choice in all patients with uncomplicated TBAD because of the inherent periprocedural complications like stroke, paraparesis, and death, as well as stent graft-induced complications (i.e., retrograde dissection or endoleaks). Thus, the TEVAR-related deaths and complications (especially paraplegia and stroke) raise concerns that moderate the better survival with TEVAR at five years. By timely identification of those patients prone for developing complications, early intervention, preferably in the subacute or early chronic phase, may improve the overall long-term outcome for these patients. Therefore, early detectable and reliable prognostic factors for adverse events are essential to stratify patients who can be treated medically and those who will benefit from rigorous follow-up and, in the long-term, from timely, or even prophylactic, TEVAR. Several studies have identified prognostic factors in TBAD such as aortic diameter, partial false lumen thrombosis, false lumen thickness, and location of the primary entry tear. Combining these clinical and radiological predictors may be essential to implement a patient-specific approach designed to intervene only in those patients who are at high risk of developing complications to improve the long-term outcomes of patients with uncomplicated Type B aortic dissection.

Indication of endovascular treatment of type B aortic dissection--literature review

Aortic dissection is a cardiovascular event of high mortality if not early diagnosed and properly treated. In Stanford type A aortic dissection, there is the involvement of the ascending aorta, whereas in type B the ascending aorta is not affected. The treatment of type A aortic dissection is mainly surgical. The hospital mortality of type B aortic dissection surgical treatment is approximately 20%, while medical therapy is 10%. However, half the patients who are discharged from hospital after medical treatment, progress to aortic complications in the following years, and the mortality in three to five years may reach 25-50%. In addition, the surgical treatment of aortic complications after medical treatment, has also a significant mortality. This way, the endovascular treatment comes up as an interesting alternative of a less invasive treatment for this disease. They presented a mortality rate lower than 10% with more than 80% success rate of occlusion and thrombosis of the false lumen. The INSTEAD TRIAL, which randomized patients with uncomplicated type B aortic dissection for optimal medical therapy and endovascular treatment in addition to optimal medical therapy, showed that after three years of follow up, patients who underwent endovascular treatment had lower mortality and aorta-related complications. Therefore, there is a current tendency to recommend the endovascular treatment as a standard for the treatment of type B aortic dissection

Geometric and flow features of type B aortic dissection: initial findings and comparison of medically treated and stented cases

Uncomplicated acute type B aortic dissections are usually treated medically, but they can become acutely complicated by rapid expansion, rupture and malperfusion syndromes and in the longer term by chronic dilatation and aortic aneurysm formation. The objective of this study is to use computational fluid dynamics reconstructions of type B aortic dissections to compare geometric and haemodynamic factors between the cases selected for medical treatment and the cases selected for thoracic endovascular aortic repair (TEVAR), and to examine whether any of these factors are associated with the outcome of the medically treated group. This study includes eight type B dissection cases, with four in each group. Aortic flow analyses were carried out based on patient-specific anatomy at initial presentation before treatment. Comparisons between the two groups show that the false lumen to true lumen volume ratio is considerably higher in patients selected for TEVAR. Results from the four medically treated cases indicate that the size of the primary entry tear is the key determinant of the false lumen flow rate, which may influence the long-term outcome of medically treated patients. Potential relations between flow related parameters based on initial anatomy and subsequent anatomical changes in the medically treatment group were examined. Our initial findings based on the limited cases are that high relative residence time is a strong predictor of subsequent false lumen thrombosis, whereas pressure difference between the true and false lumen as well as the location of the largest pressure difference may be associated with the likelihood of subsequent aortic expansion.

Predicting flow in aortic dissection: comparison of computational model with PC-MRI velocity measurements

Aortic dissection is a life-threatening process in which the weakened wall develops a tear, causing separation of wall layers. The dissected layers separate the original true aortic lumen and a newly created false lumen. If untreated, the condition can be fatal. Flow rate in the false lumen is a key feature for false lumen patency, which has been regarded as one of the most important predictors of adverse early and later outcomes. Detailed flow analysis in the dissected aorta may assist vascular surgeons in making treatment decisions, but computational models to simulate flow in aortic dissections often involve several assumptions. The purpose of this study is to assess the computational models adopted in previous studies by comparison with in vivo velocity data obtained by means of phase-contrast magnetic resonance imaging (PC-MRI). Aortic dissection geometry was reconstructed from computed tomography (CT) images, while PC-MRI velocity data were used to define inflow conditions and to provide distal velocity components for comparison with the simulation results. The computational fluid dynamics (CFD) simulation incorporated a laminar-turbulent transition model, which is necessary for adequate flow simulation in aortic conditions. Velocity contours from PC-MRI and CFD in the two lumens at the distal plane were compared at four representative time points in the pulse cycle. The computational model successfully captured the complex regions of flow reversal and recirculation qualitatively, although quantitative differences exist. With a rigid wall assumption and exclusion of arch branches, the CFD model over-predicted the false lumen flow rate by 25% at peak systole. Nevertheless, an overall good agreement was achieved, confirming the physiological relevance and validity of the computational model for type B aortic dissection with a relatively stiff dissection flap.

Survival after endovascular therapy in patients with type B aortic dissection: a report from the International Registry of Acute Aortic Dissection (IRAD)

OBJECTIVES

This study sought to evaluate long-term survival in type B aortic dissection patients treated with thoracic endovascular aortic repair (TEVAR) therapy.

BACKGROUND

Historical data have supported medical therapy in type B acute aortic dissection (TBAAD) patients. Recent advances in TEVAR appear to improve in-hospital mortality.

METHODS

We examined 1,129 consecutive patients with TBAAD enrolled in IRAD (International Registry of Acute Aortic Dissection) between 1995 and 2012 who received medical (n = 853, 75.6%) or TEVAR (n = 276, 24.4%) therapy.

RESULTS

Clinical history was similar between groups. TEVAR patients were more likely to present with a pulse deficit (28.3% vs. 13.4%, p < 0.001) and lower extremity ischemia (16.8% vs. 3.6%, p < 0.001), and to characterize their pain as the "worst pain ever" (27.5% vs. 15.7%, p < 0.001). TEVAR patients were also most likely to present with complicated acute aortic dissection, defined as shock, periaortic hematoma, signs of malperfusion, stroke, spinal cord ischemia, mesenteric ischemia, and/or renal failure (61.7% vs. 37.2%). In-hospital mortality was similar in patients managed with endovascular repair (10.9% vs. 8.7%, p = 0.273) compared with medically managed patients. One-year mortality was also similar in both groups (8.1% endovascular vs. 9.8% medical, p = 0.604). Among adverse events during follow-up, aortic growth/new aneurysm was most common, occurring in 73.3% of patients with medical therapy and in 62.7% of patients after TEVAR, based on 5-year Kaplan-Meier estimates. Kaplan-Meier survival estimates showed that patients undergoing TEVAR had a lower death rate (15.5% vs. 29.0%, p = 0.018) at 5 years.

CONCLUSIONS

Results from IRAD show that TEVAR is associated with lower mortality over a 5-year period than medical therapy for TBAAD. Further randomized trials with long-term follow-up are needed.

Hybrid approach in an acute type B aortic dissection in a female patient after having a renal transplant

This study describes our experiences with a 44-year-old woman who developed acute type B aortic dissection and elected emergency surgery 3 years after a renal transplant. This led to acute ischemia in the right lower extremity. The first stage of surgery was to implant an extra-anatomic (pretracheal) bypass with a GORE-TEX prosthesis from the brachiocephalic trunk to the left common carotid artery. The second stage was implanting a stent graft into the aortic arch that covered the left common carotid artery and the left subclavian artery. The third stage was to insert a stent graft that involved the entire thoracic aorta and proximal segment of the abdominal aorta to the celiac trunk, with the right axillary and left femoral approach. The fourth stage was an extra-anatomic (suprapubic) bypass with the GORE-TEX prosthesis from the left femoral artery to the right femoral artery. Surgery resulted in normal blood supply to the organs and restored renal function.

Interdisciplinary team approach for complicated type B aortic dissection with concomitant hematothorax by endovascular stent grafting and left side mini thoracotomy: a case report

Due to high mortality rates in surgical treatment, total endovascular stent grafting has become a promising therapeutic option in patients with acute aortic dissection type B. In our case, a 76- year- old patient with acute ruptured aortic dissection type B and hematothorax achieved concomitant total endovascular stent grafting and left side mini thoracotomy. With moderate neurologic impairment he was discharged from hospital after 20 days.

This case shows that early mortality of live threatening acute aortic dissection type B with hemorrhagic pleural effusion may be reduced by total endovascular stent grafting and concomitant mini thoracotomy.

Recent advances in the diagnosis of acute aortic syndromes

INTRODUCTION

Acute aortic syndrome (AAS) is an acute lesion of the aortic wall involving the aortic media. In patients presenting with AAS, establishing a timely diagnosis is of paramount importance as mortality from AAS increases by 1 - 2% per hour. Acute aortic syndrome comprises a variety of pathologically distinct life-threatening conditions such as aortic dissection, intramural hematoma (IMH) of the aorta, penetrating aortic ulcer (PAU), traumatic transection and symptomatic aortic aneurysm.

AREAS COVERED

The aim of this article was to review recent progress in the diagnosis and therapeutic management of these syndromes. In the past few years, imaging techniques have increased our understanding of the natural history of these disease entities. Patients presenting with AAS require immediate diagnosis in order to rapidly initiate adequate therapeutic measures. Diagnostic imaging modalities that can be used for diagnosing this condition are transthoracic and transesophageal echocardiography (TTE and TEE, respectively), computed tomography angiography (CTA), magnetic resonance imaging and angiography in combination with intravascular ultrasound (IVUS).

EXPERT OPINION

Patients presenting with AAS require immediate diagnosis for rapid initiation of adequate therapeutic measures. The best method to correctly diagnose acute aortic dissection and its complications is complementary use of CTA, TEE and angiography in combination with IVUS to improve visualization of aortic syndromes and to guide aortic stent graft implantation.

Risk factors for 1-year mortality after thoracic endovascular aortic repair

OBJECTIVE

Thoracic endovascular aortic repair, although physiologically well tolerated, may fail to confer significant survival benefit in some high-risk patients. In an effort to identify patients most likely to benefit from intervention, the present study sought to determine the risk factors for 1-year mortality after thoracic endovascular aortic repair.

METHODS

A retrospective review was performed on prospectively collected data from all patients undergoing thoracic endovascular aortic repair from 2002 to 2010 at a single institution. Univariate analysis and multivariate Cox proportional hazards regression analysis were used to identify risk factors associated with mortality within 1 year after thoracic endovascular aortic repair.

RESULTS

During the study period, 282 patients underwent at least 1 thoracic endovascular aortic repair; index procedures included descending aortic repair (n = 189), hybrid arch repair (n = 55), and hybrid thoracoabdominal repair (n = 38). The 30-day/in-hospital mortality was 7.4% (n = 21) and the overall 1-year mortality was 19% (n = 54). Cardiopulmonary pathologies were the most common cause of nonperioperative 1-year mortality (22%, n = 12). Multivariate modeling demonstrated 3 variables independently associated with 1-year mortality: age older than 75 years (hazard ratio, 2.26; P = .005), aortic diameter greater than 6.5 cm (hazard ratio, 2.20; P = .007), and American Society of Anesthesiologists class 4 (hazard ratio, 1.85; P = .049). A baseline creatinine greater than 1.5 mg/dL (hazard ratio, 1.79; P = .05) and congestive heart failure (hazard ratio, 1.87; P = .08) were also retained in the final model. These 5 variables explained a large proportion of the risk of 1-year mortality (C statistic = 0.74).

CONCLUSIONS

Age older than 75 years, aortic diameter greater than 6.5 cm, and American Society of Anesthesiologists class 4 are independently associated with 1-year mortality after thoracic endovascular aortic repair. These clinical characteristics may help risk-stratify patients undergoing thoracic endovascular aortic repair and identify those unlikely to derive a long-term survival benefit from the procedure.

A systematic review of mid-term outcomes of thoracic endovascular repair (TEVAR) of chronic type B aortic dissection

OBJECTIVE AND DESIGN

The role of Thoracic Endovascular Repair (TEVAR) in chronic type B aortic dissection remains controversial and its mid-term success as an alternative to open repair or best medical therapy remains unknown. The aim of the present study was to provide a systematic review of mid-term outcomes of TEVAR for chronic type B aortic dissection.

MATERIALS AND METHODS

Medline, trial registries, conference proceedings and article reference lists from 1950 to January 2011 were searched to identify case series reporting mid-term outcomes of TEVAR in chronic type B dissection. Data were extracted for review.

RESULTS

17 studies of 567 patients were reviewed. The technical success rate was 89.9% (range 77.6-100). Mid-term mortality was 9.2% (46/499) and survival ranged from 59.1 to 100% in studies with a median follow-up of 24 months. 8.1% of patients (25/309) developed endoleak, predominantly type I. Re-intervention rates ranged from 0 to 60% in studies with a median follow-up of 31 months. 7.8% of patients (26/332) developed aneurysms of the distal aorta or continued false lumen perfusion with aneurysmal dilatation. Rare complications included delayed retrograde type A dissection (0.67%), aorto-oesophageal fistula (0.22%) and neurological complications (paraplegia 2/447, 0.45%; stroke 7/475, 1.5%).

CONCLUSION

The absolute benefit of TEVAR over alternative treatments for chronic B-AD remains uncertain. The lack of natural history data for medically treated cases, significant heterogeneity in case selection and absence of consensus reporting standards for intervention are significant obstructions to interpreting the mid-term data. High-quality data from registries and clinical trials are required to address these challenges.

Management of acute complicated and uncomplicated type B dissection of the aorta: focus on endovascular stent grafting

Endovascular repair of aortic dissection is the subject of multiple studies. This article aims to review the current literature on Type B complicated and uncomplicated dissection, including indications for medical therapy, open surgical therapy, and endovascular therapy. The review suggests a benefit for thoracic endovascular aortic repair in complicated dissection and medical therapy for uncomplicated dissection. Upcoming trials may shed more light on this issue.

How to manage the left subclavian artery during endovascular stenting for thoracic aortic dissection? An assessment of the evidence

BACKGROUND

Despite the publication of recent guidelines for management of the left subclavian artery (LSA) during endovascular stenting procedures of the thoracic aorta, specific management for those presenting with dissection remains unclear. This systematic review attempts to address this issue.

METHODS

Systematic assessment of the published data on thoracic aorta dissection was performed identifying 46 studies, which incorporated 1,275 patients. Primary outcomes included the prevalence of left arm ischemia, stroke, spinal cord ischemia, endoleak, stent migration, and mortality. Outcomes were compared between patients with and without LSA coverage and revascularization incorporating factors such as the number of stents used, length of aorta covered, urgency of intervention, and type of dissection (acute or chronic). Statistical pooling techniques, χ(2) tests, and Fisher's exact testing were used for group comparisons.

RESULTS

As compared with other outcomes, LSA coverage without revascularization in the presence of aortic dissection is much more likely to be complicated by left arm ischemia (prevalence increased from 0.0% to 4.0% [p = 0.021]), stroke (prevalence increased from 1.4% to 9.0% [p = 0.009]), and endoleak (prevalence increased from 4.0% to 29.3% [p = 0.001]). However, revascularization was not shown to reverse these effects. Longer aortic coverage (≥ 150 mm) was associated with an increased prevalence of spinal cord ischemia (from 1.3% to 12.5% [p = 0.011]) and mortality (from 1.3% to 15.6% [p = 0.003]).

CONCLUSION

In patients undergoing endovascular stenting for thoracic aortic dissection, in cases where LSA coverage is necessary, revascularization should be considered before the procedure to avoid complications such as left arm ischemia, stroke, and endoleak, and where feasible, an appropriate preoperative assessment should be carried out.

Current strategy of endovascular aortic repair for thoracic aortic aneurysms

Thoracic aortic aneurysms are extremely burdensome to treat owing to their surgical complexity. In particular, major postoperative complications lower significantly patients' quality of life. Surgical treatment has recently shifted to thoracic endovascular aortic repair (TEVAR) to respect the patients' needs and improve postoperative quality of life. This procedure is radical and innovated for thoracic aortic pathology, but the devices and the delivery systems are immature because only a little over a decade and a half has passed since starting to use them. Ready-made stent-grafts were originally indicated only for degenerated aortic aneurysms, but aortic dissection and traumatic aortic transection will become the next targets for TEVAR. This review addresses the history and changes in TEVAR as well as the current TEVAR strategy. Finally, we describe a new trial of TEVAR for aortic dissections, traumatic aortic transections, and aortic arch aneurysms.