Infrarenal Aortic Treatment With AFX2 Endograft: Results From a Multicentric, International, Non-Randomized, Prospective Registry-the AFX2-LIVE Study.

INTRODUCTION: To confirm real-world clinical practice results reported with anatomically fixed bifurcated endograft, a physician-initiated study was designed-AFX2-LIVE registry. MATERIALS AND METHODS: From November 2019 to August 2021, investigators enrolled all consecutive patients treated with AFX2 (Endologix Inc., Irvine, CA, USA) endograft. Patients with abdominal aortic aneurysms (AAAs), penetrating aortic ulcers (PAU), and isolated infrarenal aortic dissections were included. Clinical and anatomical data, including baseline, intraoperative, and in-hospital details, as well as follow-up data, were collected in an anonymized prospectively compiled database. The primary endpoint of this study was to evaluate the technical and clinical success of endovascular aortic repair (EVAR) using AFX2 endograft. RESULTS: A total of 535 patients were enrolled from 43 Italian and Spanish centers and analyzed according to the protocol. Four hundred eighty-nine patients were male (91.4%), with a mean age of 75±8.92 years (range 52-94). Four hundred sixty-six patients (87.1%) were treated for AAA, 49 (9.3%) for PAU, and 20 (3.6%) for isolated abdominal aortic dissection. A proximal extension was needed in 48% of the cases. Assisted technical success was achieved in all but one patient (99.8%). At 30 days follow-up, no AAA-related deaths were recorded, and nine patients (1.6%) required reintervention. At a mean follow-up period of 15.22±13.65 (range 1-53) months, data were available for 479 patients (89.5%). Clinical success was achieved in 98.2% (95% confidence interval [CI]: 96.4-99.1) at 3 months, 93.9% (95% CI: 90.1-96.1) at 1 year, and 74.1% (95% CI: 62.8-82.4) at 4 years follow-up. The estimated freedom from all-cause mortality was 97.7%, 93.4%, 81.6%, 77.5%, and 70.9%, and freedom from AAA-related mortality was 100%, 99.6%, 99.6%, 99.6%, and 97.3% at 3, 12, 24, 36, and 48 months, respectively. Twenty reinterventions (3.7%) were required in 19 patients, of which 3 late open conversions (0.6%) were performed, and 2 AAA-related deaths were observed. CONCLUSION: This study demonstrated excellent clinical and technical success rates of EVAR with anatomically fixed endografts, providing valuable insights into real-world clinical outcomes. CLINICAL IMPACT: The AFX2-LIVE study could have a significant impact by providing robust evidence supporting the effectiveness and safety of EVAR using bifurcated endografts with anatomical fixation in real-world clinical practice, ultimately leading to improved outcomes and enhanced patient care in the management of abdominal aortic pathologies.

Variability in the Treatment of High-Risk Type B Aortic Dissection at a Single Center.

Although there are established high-risk features in acute type B aortic dissection (TBAD), its management is variable. This study characterizes complicated, uncomplicated, and high-risk TBAD in addition to their management and outcomes to gain insight into the actual significance of these high-risk features and the reality of real-world practice in managing TBAD. A retrospective review of 62 patients was conducted. Patient demographics, management, and outcomes were characterized and evaluated with Pearson's χ2 test, Fisher's exact test, or analysis of variance. Of the 32 high-risk TBADs, 66% (n = 21) received endovascular repair, 31% (n = 10) were medically managed, and 3% (n = 1) received hybrid (open and endovascular) repair. Refractory hypertension and pain (52%, n = 11) were the most common high-risk features in patients with high-risk TBAD who received endovascular repair. A maximum aortic diameter of >40 mm (67%, n = 6) was the most common high-risk feature in patients who received medical management. The most prevalent high-risk feature for all treatment groups in the high-risk TBADs was an aortic diameter of >40 mm (n = 16; 50%). Adverse postoperative outcomes were highest in the high-risk and complicated groups with endoleak as the most common adverse outcome (high-risk 12.9%, complicated 13.6%). Of the 62 patients, 47% (n = 26) had follow-up since their admission with an average follow-up time of 69 ± 166 days. The significance of high-risk features in the management of high-risk TBAD remains unclear. This single-center experience with managing acute TBAD reveals the reality of inadequate follow-up that may be specific to this disease process. This highlights a need to direct more efforts to assess long-term outcomes after treatment.

Recognition and initial management of acute aortic dissection.

Acute aortic dissection is a cardiovascular emergency that should be recognised on presentation in the Emergency Department (ED) because clinical outcome is time-dependent. In suspected cases of acute aortic dissection, immediate imaging with chest computed tomography scan followed by transthoracic echocardiography (TTE) is essential to confirm diagnosis. Immediate medical management is aimed at controlling the heart rate (60-80 beats/min), systolic blood pressure (100-120 mmHg) and pain. Patients with Type A acute aortic dissection should immediately be referred to the cardiothoracic surgeons for emergency aortic surgery while those with Type B acute aortic dissection should be referred to the vascular surgeons for surgical/endovascular interventions if indicated.

Dissection flap fenestration can reduce re-apposition force of the false lumen in type-B aortic dissection: a computational and bench study.

Thoracic endovascular aortic repair (TEVAR) has been widely adopted as a standard for treating complicated acute and high-risk uncomplicated Stanford Type-B aortic dissections. The treatment redirects the blood flow towards the true lumen by covering the proximal dissection tear which promotes sealing of the false lumen. Despite advances in TEVAR, over 30% of Type-B dissection patients require additional interventions. This is primarily due to the presence of a persistent patent false lumen post-TEVAR that could potentially enlarge over time. We propose a novel technique, called slit fenestration pattern creation, which reduces the forces for re-apposition of the dissection flap (i.e., increase the compliance of the flap). We compute the optimal slit fenestration design using a virtual design of experiment (DOE) and demonstrate its effectiveness in reducing the re-apposition forces through computational simulations and benchtop experiments using porcine aortas. The findings suggest this potential therapy can drastically reduce the radial loading required to re-appose a dissected flap against the aortic wall to ensure reconstitution of the aortic wall (remodeling).

Radiographic complicated and uncomplicated descending aortic dissections: aortic morphological differences by CT angiography and risk factor analysis.

AIMS: To identify radiographic differences between patients with uncomplicated and complicated descending aortic dissections. METHODS AND RESULTS: Between April 2009 and July 2021, 209 patients with acute descending aortic dissections were analysed as complicated (malperfusion, rupture, diameter progress, and diameter ≥ 55 mm) or uncomplicated. Detailed CTA measurements (slice thickness ≤ 3 mm) were taken in multiplanar reconstruction. A composite endpoint (early aortic failure) was defined as reoperation, diameter progression, and early mortality. Seventy-seven patients were female (36.8%) [complicated n = 27 (36.5%); uncomplicated n = 50 (37.0%) P = 1.00]. Seventy-four (35%) patients were categorized as morphologically complicated, and 135 (65%) as uncomplicated. In patients with complicated dissections, the dissection extended more frequently to the aortic bifurcation (P = 0.044), the coeliac trunk (P = 0.003), the superior mesenteric artery (P = 0.007), and both iliac arteries (P < 0.001) originated less frequently from the true lumen. The length of the most proximal communication (entry) in type B aortic dissection was longer, 14.0 mm [12.0 mm; 27.0 mm] vs. 6.0 mm [4,0 mm; 13.0 mm] in complicated cases (P = 0.005). Identified risk factors for adverse aortic events were connective tissue disease [HR 8.0 (1.9-33.7 95% CI HR)], length of the aortic arch [HR 4.7 (1.5-15.1 95% CI HR)], a false lumen diameter > 19.38 mm [HR 3.389 (1.1-10.2 95% CI HR)], and origin of the inferior mesenteric artery from the false lumen [HR 4.2 (1.0-5.5 95% CI HR)]. CONCLUSION: We identified significant morphological differences and predictors for adverse events in patients presenting complicated and uncomplicated descending dissections. Our morphological findings will help guide future aortic therapies, taking a tailored patient approach.

Multilayer Stent for Emergency Treatment of Acute Type B Aortic Dissection: A Case Report.

PURPOSE: We report the case of an acute type B dissection with high-risk features treated with multilayer stent. CASE REPORT: A 50-year-old female patient presented to the emergency department with an acute type B aortic dissection. Conservative medical treatment did control blood pressure but did not alleviate her dissection symptoms. She was treated endovascularly with multilayer stents extensively covering the whole dissected area. HThe aortic arch side branches, visceral arteries and renal arteries remained patent after treatment. The recovery was uneventful, and she was discharged the day after the intervention. At 6- and 12-month follow-up, the patient remained asymptomatic, the true lumen volume increased and all side branches remained patent. CONCLUSION: We present a case of the use of a multilayer stent for acute type B aortic dissection. This technique allows to treat the whole dissection with low risk of paraplegia or side branch occlusion. Long-term results of ongoing clinical studies should confirm the place of the multilayer stent as a treatment option for type B aortic dissection.

Male-Female Differences in Acute Type B Aortic Dissection.

BACKGROUND: Acute type B aortic dissection is a cardiovascular emergency with considerable mortality and morbidity risk. Male-female differences have been observed in cardiovascular disease; however, literature on type B aortic dissection is scarce. METHODS AND RESULTS: A retrospective cohort study was conducted including all consecutive patients with acute type B aortic dissection between 2007 and 2017 in 4 tertiary hospitals using patient files and questionnaires for late morbidity. In total, 384 patients were included with a follow-up of 6.1 (range, 0.02-14.8) years, of which 41% (n=156) were female. Women presented at an older age than men (67 [interquartile range (IQR), 57-73] versus 62 [IQR, 52-71]; P=0.015). Prior abdominal aortic aneurysm (6% versus 15%; P=0.009), distally extending dissections (71 versus 85%; P=0.001), and clinical malperfusion (18% versus 32%; P=0.002) were less frequently observed in women. Absolute maximal descending aortic diameters were smaller in women (36 [IQR: 33-40] mm versus 39 [IQR, 36-43] mm; P<0.001), while indexed for body surface area diameters were larger in women (20 [IQR, 18-23] mm/m2 versus 19 [IQR, 17-21] mm/m2). No male-female differences were found in treatment choice; however, indications for invasive treatment were different (P<0.001). Early mortality rate was 9.6% in women and 11.8% in men (P=0.60). The 5-year survival was 83% (95% CI, 77-89) for women and 84% (95% CI, 79-89) for men (P=0.90). No male-female differences were observed in late (re)interventions. CONCLUSIONS: No male-female differences were found in management, early or late death, and morbidity in patients presenting with acute type B aortic dissection, despite distinct clinical profiles at presentation. More details on the impact of age and type of intervention are warranted in future studies.

Standing the test of time: total aortic remodeling 13 years after TEVAR for acute type B aortic dissection.

Long-term outcome after thoracic endovascular aortic repair (TEVAR) of acute type B aortic dissection (aTBAD) is still underreported in current literature. This case report shows persistence of aortic remodeling without secondary complication or need of reintervention 13 years after TEVAR. A 45-year-old woman was referred to the emergency room with aTBAD. Due to early diameter progression in combination with therapy-refractory pain and uncontrolled hypertension, TEVAR was performed. Hereafter, the patient showed complete remodeling of the descending thoracic aorta without persistent false lumen perfusion in this segment and with stable true and false lumen diameter in the untreated abdominal segment for a 13-year period. No aortic-related reintervention was needed. With contemporary devices and adapted therapy, TEVAR seems able to treat complex thoracic disease. Long-term follow-up (FU) is mandatory to monitor the efficacy and durability of endovascular treatment in aortic disease.

A rare case of an acute type B aortic dissection contained infrarenal rupture of the false lumen after prior endovascular abdominal aneurysm repair.

New-onset acute type B aortic dissection after prior endovascular aneurysm repair is extremely rare. Extension of an aortic dissection can cause destabilization of the previously implanted stent graft, thrombosis of the stent graft, and rupture of the aneurysmal sac, with high mortality without therapy. This report describes the case of a 66-year-old patient complaining of sudden abdominal pain radiating to both flanks. Computed tomography angiography of the aorta revealed acute type B aortic dissection with infrarenal rupture of the false lumen after endovascular abdominal aneurysm repair 5 years prior. The patient underwent infrarenal open surgical conversion with suprarenal aortic clamping and implantation of a bifurcated Dacron graft. Postoperatively, no serious complications resulted from the treatment, except for fascial dehiscence. In such cases, the patients can be treated in an emergency situation with open repair, despite the high risk of complications and mortality.

Risk of Type B Dissection in Marfan Syndrome: The Cornell Aortic Aneurysm Registry.

BACKGROUND: With preventive aortic grafting decreasing the incidence of type A dissections in Marfan syndrome (MFS), most dissections are now type B, for which risk factors remain largely uncertain. OBJECTIVES: We explored the determinants of type B dissection risk in a large, single-center MFS registry. METHODS: Demographic and anthropometric features, cardiovascular disease, and surgical history were compared in patients with MFS with and without type B dissection. RESULTS: Of 336 patients with MFS, 47 (14%) experienced a type B dissection (vs type A in 9%). Patients with type B dissection were more likely to have undergone elective aortic root replacement (ARR) (79 vs 46%; P < 0.001). Of the patients, 55% had type B dissection a mean of 13.3 years after ARR, whereas 45% experienced type B dissection before or in the absence of ARR; 41 patients (87%) were aware of their MFS diagnosis before type B dissection. Among those with predissection imaging, the descending aorta was normal or minimally dilated (<4.0 cm) in 88%. In multivariable analyses, patients with type B dissection were more likely to have undergone ARR and independent mitral valve surgery, to have had a type II dissection, and to have lived longer. CONCLUSIONS: In our contemporary cohort, type B dissections are more common than type A dissections and occur at traditional nonsurgical thresholds. The associations of type B dissection with ARR, independent mitral valve surgery, and type II dissection suggest a more severe phenotype in the setting of prolonged life expectancy.

Establishing and Validating a Morphological Prediction Model Based on CTA to Evaluate the Incidence of Type-B Dissection.

Background: Many patients with Type B aortic dissection (TBAD) may not show noticeable symptoms until they become intervention and help prevent critically ill, which can result in fatal outcomes. Thus, it is crucial to screen people at high risk of TBAD and initiate the necessary preventive and therapeutic measures before irreversible harm occurs. By developing a prediction model for aortic arch morphology, it is possible to accurately identify those at high risk and take prompt action to prevent the adverse consequences of TBAD. This approach can facilitate timely the development of serious illnesses. Method: The predictive model was established in a primary population consisting of 173 patients diagnosed with acute Stanford TBAD, with data collected from January 2017 and December 2018, as well as 534 patients with healthy aortas, with data collected from April 2018 and December 2018. Explicitly, the data were randomly separated into the derivation set and validation set in a 7:3 ratio. Geometric and anatomical features were extracted from a three-dimensional multiplanar reconstruction of the aortic arch. The LASSO regression model was utilized to minimize the data dimension and choose relevant features. Multivariable logistic regression analysis and backward stepwise selection were employed for predictive model generation, combining demographic and clinical features as well as geometric and anatomical features. The predictive model's performance was evaluated by examining its calibration, discrimination, and clinical benefit. Finally, we also conducted internal verification. Results: After applying LASSO logistic regression and backward stepwise selection, 12 features were entered into the prediction model. Age, aortic arch angle, total thoracic aorta distance, ascending aorta tortuosity, aortic arch tortuosity, distal descending aorta tortuosity, and type III arch were protective factors, while male sex, hypertension, aortic arch height, and aortic arch distance were risk factors. The model exhibited satisfactory discrimination (AUC, 0.917 [95% CI, 0.890-0.945]) and good calibration in the derivation set. Applying the predictive model to the validation set also provided satisfactory discrimination (AUC, 0.909 [95% CI, 0.864-0.953]) and good calibration. The TBAD nomogram for clinical use was established. Conclusions: This study demonstrates that a multivariable logistic regression model can be used to predict TBAD patients.

"Big Data" Analyses Underlie Clinical Discoveries at the Aortic Institute.

This issue of the Yale Journal of Biology and Medicine (YJBM) focuses on Big Data and precision analytics in medical research. At the Aortic Institute at Yale New Haven Hospital, the vast majority of our investigations have emanated from our large, prospective clinical database of patients with thoracic aortic aneurysm (TAA), supplemented by ultra-large genetic sequencing files. Among the fundamental clinical and scientific discoveries enabled by application of advanced statistical and artificial intelligence techniques on these clinical and genetic databases are the following: From analysis of Traditional "Big Data" (Large data sets). 1. Ascending aortic aneurysms should be resected at 5 cm to prevent dissection and rupture. 2. Indexing aortic size to height improves aortic risk prognostication. 3. Aortic root dilatation is more malignant than mid-ascending aortic dilatation. 4. Ascending aortic aneurysm patients with bicuspid aortic valves do not carry the poorer prognosis previously postulated. 5. The descending and thoracoabdominal aorta are capable of rupture without dissection. 6. Female patients with TAA do more poorly than male patients. 7. Ascending aortic length is even better than aortic diameter at predicting dissection. 8. A "silver lining" of TAA disease is the profound, lifelong protection from atherosclerosis. From Modern "Big Data" Machine Learning/Artificial Intelligence analysis: 1. Machine learning models for TAA: outperforming traditional anatomic criteria. 2. Genetic testing for TAA and dissection and discovery of novel causative genes. 3. Phenotypic genetic characterization by Artificial Intelligence. 4. Panel of RNAs "detects" TAA. Such findings, based on (a) long-standing application of advanced conventional statistical analysis to large clinical data sets, and (b) recent application of advanced machine learning/artificial intelligence to large genetic data sets at the Yale Aortic Institute have advanced the diagnosis and medical and surgical treatment of TAA.

Bare Stent Fracture After TEVAR With the Modified Restrictive Bare Stent (RBS) Technique in Type B Aortic Dissections.

PURPOSE: The aim was to assess the mid-term aortic remodeling and bare-metal stent (BMS) integrity of the restricted bare stent (RBS) technique reconstruction in aortic dissections. MATERIALS AND METHODS: This retrospective cohort study included prospectively collected patients treated with the modified RBS technique between 2017 and 2020. The preoperative, postoperative, and last follow-up computed tomographic (CT) scans were analyzed in the centerline at the mid-descending, celiac trunk (CeT), and the mid-abdominal levels for false lumen (FL) patency, aortic diameter, and true lumen (TL) diameter changes. Bare-metal stent integrity was assessed in the 3-dimensional multiplanar reformats. RESULTS: The median follow-up of the cohort (n=17) was 26 (11, 45) months. The procedure was mainly performed with the Relay NBS endograft (15/17; 88%) + E-XL BMS (17/17; 100%). Postoperative mortality, paraplegia, stroke, renovisceral vessel loss, and type I and III endoleaks were not observed. BMS fractured in 6 patients (6/17; 36%), damaged the dissection flap in 4/17 (24%), and led to the reperfusion of the FL and re-interventions with TEVAR (4/17; 24%). Two patients without FL reperfusion showed stable CT follow-ups 13 and 17 months after the fracture diagnosis. The TL expansion was seen at all landmarks and peaked in the thoracic aorta (+10; 6, 15; p<0.001). The FL thrombosis after modified RBS was only relevant in the thoracic aorta (p<0.001) and at CeT (p=0.003). The aortic diameter was stable in the thoracic aorta and increased at distal landmarks (CeT [+5; 1, 10; p=0.001]; mid-abdominal [+3; 1, 5; p=0.004]). CONCLUSION: The modified RBS technique could not stop aortic growth below the diaphragm and prevent new membrane rupture due to the fractures of the BMS and consecutive flap damage with the reperfusion of the FL. CLINICAL IMPACT: The treatment of complicated type B aortic dissections with TEVAR has become a standard. Particularly, patients with true lumen collapse and malperfusion may benefit from a more aggressive treatment strategy including proximal TEVAR and distal bare-metal stent implantation to re-open the true lumen and to prevent distal stent-induced new entry. However, this study reports the challenges of this approach with a high rate of bare-metal stent fractures during the follow-up. The fractures that occurred at the site of vertical nitinol bridges led to the dissection membrane ruptures and the reperfusion of the false lumen with consecutive dilatation. A close follow-up is mandatory to detect this complication and to treat the patients with TEVAR extension.

Outcome of Stanford type B dissection in patients with Marfan syndrome.

OBJECTIVES: The aim of this study was to determine the outcome of Stanford type B aortic dissection in patients with Marfan syndrome (MFS) and to evaluate aortic diameters at time of dissection as well as the impact of previous aortic root replacement. METHODS: Analysis of all patients with MFS fulfilling Ghent criteria seen at this institution since 1995 until 2022. RESULTS: Thirty-six (19%) out of 188 patients with MFS suffered from Stanford type B aortic dissection during the study period. The Mean aortic diameter at the time of dissection was 39.0 mm [95% confidence interval (CI): 35.6-42.3]. The mean pre-dissection diameter (available in 25% of patients) was 32.1 mm (95% CI: 28.0-36.3) and the mean expansion was 19% (95% CI: 11.9-26.2). There was no correlation between age and diameter at the time of dissection (<20, 21-30, 31-40, 41-50, 51-60, <61 years; P = 0.78). Freedom from intervention after dissection was 53%, 44% and 33% at 1, 5 and 10 years. Aortic growth rate in those patients that had to undergo intervention within the 1st year after dissection was 10.2 mm/year (95% CI: 4.4-15.9) compared to 5.8 mm/year (95% CI: 3.3-8.3, P = 0.109) in those thereafter. The mean time between dissection and intervention was 1.8 years (95% CI: 0.6-3.0). While type B dissection seems more frequent after previous elective aortic repair (58% vs 42%), there was no difference between valve-sparing root replacement (VSRR) compared to Bentall procedures [Hazard ratio (HR) for VSRR 0.78, 95% CI: 0.31-2.0, P-value = 0.61]. The mean age of the entire population at the end of follow-up was 42 years (95% CI: 39.2-44.7). The mean follow-up time was 9 years (95% CI: 7.8-10.4). CONCLUSIONS: Stanford type B dissection in patients with MFS occurs far below accepted thresholds for intervention. Risk for type B dissection is present throughout lifetime and two-thirds of patients need an intervention after dissection. There is no difference in freedom from type B dissection between a Bentall procedure and a VSRR.

Contemporary outcomes of open repair of acute complicated type B aortic dissection.

OBJECTIVE: Open repair of acute complicated type B aortic dissection (ACTBAD), required when endovascular repair is not possible, is historically considered high-risk. We analyze our experience with this high-risk cohort compared with the standard cohort. METHODS: We identified consecutive patients undergoing descending thoracic or thoracoabdominal aortic aneurysm (TAAA) repair from 1997 to 2021. Patients with ACTBAD were compared with those having surgery for other reasons. Logistic regression was used to identify associations with major adverse events (MAEs). Five-year survival and competing risk of reintervention were calculated. RESULTS: Of 926 patients, 75 (8.1%) had ACTBAD. Indications included rupture (25/75), malperfusion (11/75), rapid expansion (26/75), recurrent pain (12/75), large aneurysm (5/75), and uncontrolled hypertension (1/75). The incidence of MAEs was similar (13.3% [10/75] vs 13.7% [117/851], P = .99). Operative mortality was 5.3% (4/75) vs 4.8% (41/851) (P = .99). Complications included tracheostomy (8%, 6/75), spinal cord ischemia (4%, 3/75), and new dialysis (2.7%, 2/75). Renal impairment, urgent/emergent operation, forced expiratory volume in 1 second ≤50%, and malperfusion were associated with MAEs, but not ACTBAD (odds ratio: 0.48, 95% confidence interval [CI]: [0.20-1.16], P = .1). At 5 and 10 years, there was no difference in survival (65.8% [95% CI: 54.6-79.2] vs 71.3% [95% CI: 67.9-74.9], P = .42, and 47.3% [95% CI: 34.5-64.7] vs 53.7% [95% CI: 49.3-58.4], P = .29, respectively) or 10-year reintervention (12.5% [95% CI: 4.3-25.3] vs 7.1% [95% CI: 4.7-10.1], P = .17, respectively). CONCLUSIONS: In an experienced center, open repair of ACTBAD can be performed with low rates of operative mortality and morbidity. Outcomes similar to elective repair are achievable even in high-risk patients with ACTBAD. In patients unsuitable for endovascular repair, transfer to a high-volume center experienced in open repair should be considered.

A Single-Center Experience With Total Percutaneous Implantation of a Low-Profile Thoracic Aortic Stent-Graft.

PURPOSE: To evaluate the safety and effectiveness of total percutaneous implantation of the Zenith Alpha Thoracic (ZTA) endograft in the treatment of diseases of the descending thoracic aorta. MATERIALS AND METHODS: A retrospective cohort study of 56 consecutive patients undergoing total percutaneous ZTA implantation between 2018 and 2020 was performed in a single center. Patients' demographics, clinical characteristics, anatomical parameters, operative details, device features, and postoperative outcomes were assessed. The primary endpoint was ongoing clinical success. A Cox regression model was used to determine the predictive factors of worse postoperative outcomes. RESULTS: Eighty-three ZTA endografts were implanted in 35 men and 21 women with a mean age of 69±11 years for the treatment of 26 degenerative aneurysms, 15 type B dissections, and 8 penetrating ulcers, among others. Primary technical success was 100%, with a 30-day ongoing clinical success rate of 94.6%. The 1-year ongoing clinical success rate was 91.1% (51 patients), and freedoms from all-cause mortality, type 1 and 3 endoleaks, and any unplanned reintervention were, respectively, 95.3%, 91.4%, and 88.2% at 1 year. During follow-up, there was one case of surgical conversion for an aorto-esophageal fistula. On the contrary, neither aneurysmal rupture nor significant aneurysmal expansion was recorded. Repair of ruptured thoracic aorta and a high ratio of sheath outer diameter to external iliac artery diameter were found to be independently associated with worse outcomes, with adjusted odds ratios of 4.4 [1.5-15.3] and 4.9 [1.1-23.9], respectively. CONCLUSION: The outcomes of total percutaneous implantation of ZTA endograft show excellent primary technical success and favorable midterm ongoing clinical success. Factors associated with worse outcomes include the repair of ruptured aorta and a high sheath to access vessel ratio.

A machine learning approach for predicting complications in descending and thoracoabdominal aortic aneurysms.

OBJECTIVE: To use machine learning to predict rupture, dissection, and all-cause mortality for patients with descending and thoracoabdominal aortic aneurysms in an effort to improve on diameter-based surgical intervention criteria. METHODS: Retrospective data from 1083 patients with descending aortic diameters 3.0 cm or greater were collected, with a mean follow-up time of 3.52 years and an average descending diameter of 4.13 cm. Six machine learning classifiers were trained using 44 variables to predict the occurrence of dissection, rupture, or all-cause mortality within 1, 2, or 5 years of initial patient encounter for a total of 54 (6 × 3 × 3) separate classifiers. Classifier performance was measured using area under the receiver operator curve. RESULTS: Machine learning models achieved area under the receiver operator curves of 0.842 to 0.872 when predicting type B dissection, 0.847 to 0.856 when predicting type B dissection or rupture, and 0.820 to 0.845 when predicting type B dissection, rupture, or all-cause mortality. All models consistently outperformed descending aortic diameter across all end points (area under the receiver operator curve = 0.713-0.733). Feature importance inspection showed that other features beyond aortic diameter, such as a history of myocardial infarction, hypertension, and patient sex, play an important role in improving risk prediction. CONCLUSIONS: This study provides surgeons with a more accurate, machine learning-based, risk-stratification metric to predict complications for patients with descending aortic aneurysms.

A retrospective study of thoracic endovascular aortic repair timing in patients with uncomplicated type B dissection who have a smoking history.

Objective: To determine the optimal timing of thoracic endovascular aortic repair (TEVAR) for patients with uncomplicated type B dissections who have a smoking history. Methods: Data from 308 consecutive patients with uncomplicated type B dissections, who have a smoking history and onset-to-TEVAR time within 90 days, were analyzed. The patients were divided into two groups: Acute and subacute phases. Univariate and multivariate regression analyses were performed. Smooth curve fitting and threshold analysis were performed to characterize the relationship between the onset-to-TEVAR time and follow-up deaths. Results: There were no significant differences between the two groups. Smooth curve fitting and threshold effect analysis showed that if early TEVAR was performed within 9.4 days from onset, there was better long-term survival and there was no significant difference after 9.4 days. Conclusion: By studying the relationship between onset-to-TEVAR time and all-cause mortality, we found that early TEVAR may have a lower all-cause mortality rate during follow-up in uncomplicated type B dissection patients who have a smoking history and within 90 days from onset.