Prevalence and Prognostic Significance of Malnutrition in Patients with Type B Aortic Dissection Undergoing Endovascular Repair.

Background: Malnutrition is a poor prognostic factor in a wide range of diseases. Nevertheless, there is a lack of data investigating the association between malnutrition and outcomes of patients with type B aortic dissection (TBAD) undergoing thoracic endovascular aortic repair (TEVAR). Therefore, the aim of the present study was to report the prevalence and clinical impact of malnutrition assessed by the controlling nutritional status (CONUT) score in TBAD patients undergoing TEVAR. Methods: The retrospective study indicated that a total of 881 patients diagnosed with TBAD and treated with TEVAR from January 2010 to December 2017 were categorized into subgroups based on their CONUT score (low ≤ 5 vs. high > 5). To assess the correlation between malnutrition and early and follow-up outcomes of TBAD patients, logistic and Cox regression analysis were utilized, incorporating inverse probability weighting. Results: Malnutrition was present in 20.3% of patients according to the CONUT score. Multivariate logistic regression analysis revealed that pre-operative CONUT score modeled as a continuous variable was an independent risk factor for prolonged intensive care unit stay (odds ratio [OR], 1.09; 95% confidence interval [CI], 1.02-1.17; p = 0.015), 30-day death (OR, 1.43; 95% CI, 1.19-1.72; p < 0.001), delirium (OR, 1.11; 95% CI, 1.01-1.23; p = 0.035) and acute kidney injury (OR, 1.09; 95% CI, 1.01-1.16; p = 0.027). During a median follow-up of 70.8 (46.1-90.8) months, 102 (11.8%) patients died (high CONUT group: 21.8% vs. low CONUT group: 9.0%; p < 0.001). Multivariable Cox proportional-hazards models showed that malnutrition was an independent predictor for follow-up mortality (hazard ratio, 1.68; 95% CI, 1.11-2.53; p = 0.014). Results remained consistent across various sensitivity analyses. Conclusions: Malnutrition assessed by the CONUT score could profoundly affect the early and follow-up prognosis in patients undergoing TEVAR. Routine pre-intervention nutritional evaluation might provide valuable prognostic information.

Predictors for thoracic aortic growth in patients with type B aortic dissection after thoracic endovascular aortic repair.

OBJECTIVE: To identify independent predictors of thoracic aortic growth in patients with type B aortic dissection (TBAD) undergoing thoracic endovascular aortic repair (TEVAR). METHODS: A retrospective analysis of the patients undergoing TEVAR for TBAD or intramural hematoma (IMH) from April 2014 to April 2023 was performed. The baseline morphological data of TBAD was established through computed tomography angiography (CTA) before discharge. Patients were divided into two groups based on aortic growth: growth and no growth. Aortic growth defined as an increase ≥5 mm in thoracic maximal aortic diameter during any serial follow-up CTA measurement. Logistic regression following propensity score matching (PSM) was used to identify independent predictors for aortic growth. Receiver operating characteristic curve and cutoff value of independent predictors were calculated. Linear regression was used to establish a correlation between anatomical variables and follow-up aortic diameter. RESULTS: A total of 145 patients with TBAD (n = 122) or IMH (n = 23) undergoing TEVAR were included, with a male of 83.4% and a mean age of 56 ± 14.1 years. Patients in growth group and no growth group was 26 (17.9%) and 119 (80.1%), respectively. After using PSM method, matched regression analysis showed residual maximal tear diameter (OR = 0.889, 95% CI 0.830-0.952, p = 0.001) and follow-up aortic diameter (OR = 0.977, 95% CI 0.965-0.989, p < 0.001) were independent predictors for aortic growth. The cutoff value was 8.55 mm for residual tear diameter and 40.65 mm for follow-up maximal aortic diameter. The residual maximal tear diameter showed a linear correlation with follow-up aortic diameter (DW = 1.74, R2 = 6.2%, p = 0.033). CONCLUSIONS: This study suggested that residual maximal tear diameter >8.55 mm and follow-up aortic diameter >40.65 mm could predict aortic growth in patients with TBAD undergoing TEVAR.

Navigating clinical appropriateness: A review of management strategies for type B aortic dissection.

Aortic dissection is a catastrophic, life-threatening event. Its management depends on the anatomic location of the intimal tear (type A v B) and the clinical presentation in type B aortic dissection. In this article, the current evidence supporting clinical practice, gaps in knowledge, and the need for more rigorous research and higher-quality studies are reviewed.

Long-term volumetric evaluation of stent-assisted balloon-induced intimal disruption and relamination of aortic dissection (STABILISE) in acute type B aortic dissection.

OBJECTIVE: To quantify the volumetric aortic remodeling of patients with acute type B aortic dissection (ATBAD) treated with the stent-assisted balloon-induced intimal disruption and relamination (STABILISE) technique. METHODS: All patients with ATBAD operated with the STABILISE technique between 2014 and 2017 with pre-operative (PreOp), post-operative (PostOp) and >12 months (follow-up) computed tomography scans were included in this study. True lumen and total aortic volume were accurately assessed in the thoracic and abdominal portions with a semi-automatic 3D tool. Associations with long-term adverse events were estimated. RESULTS: Seventeen patients were measured at PreOp, PostOp and a mean follow-up of 19±8 months. The false lumen to total volume ratio decreased on average from 63% to 18% after STABILISE (p<0.001) and remained around 12% at follow-up. These remodeling was more pronounced in the thoracic aorta (7%) than in the abdominal aorta (28%). The trend in aortic size growth was stronger for volumes than for maximum areas or diameters (p<0.001, p<0.05 and p<0.05, respectively). Adverse events were identified in 4 patients during a long-term follow-up of 76±18 months. The only aortic size variable assessed preoperatively that was associated with undesirable events was the total volume of the abdominal aorta (p<0.05). CONCLUSIONS: A volumetric analysis of dissected aortic size after the STABILISE procedure allowed accurate quantification of mid-term aortic remodeling and helped to identify the abdominal aortic volume as a preoperative variable associated with undesirable long-term events.

Central nervous injury risk factors after endovascular repair of a thoracic aortic aneurysm with type B aortic dissection.

BACKGROUND: Aortic dissection is the deadliest disease of the cardiovascular system. Type B aortic dissection accounts for 30%-60% of aortic dissections and is mainly treated by endovascular repair of thoracic endovascular aneurysm repair (TEVAR). However, patients are prone to various complications after surgery, with central nervous system injury being the most common, which seriously affects their prognosis and increases the risk of disability and death. Therefore, exploring the risk factors of central nervous system injury after TEVAR can provide a basis for its prevention and control. AIM: To investigate the risk factors for central nervous system injury after the repair of a thoracic endovascular aneurysm with type B aortic dissection. METHODS: We enrolled 306 patients with type B aortic dissection who underwent TEVAR at our hospital between December 2019 and October 2022. The patients were categorized into injury (n = 159) and non-injury (n = 147) groups based on central nervous system injury following surgery. The risk factors for central nervous system injury after TEVAR for type B aortic dissection were screened by comparing the two groups. Multivariate logistic regression analysis was performed. RESULTS: The Association between age, history of hypertension, blood pH value, surgery, mechanical ventilation, intensive care unit stay, postoperative recovery times on the first day after surgery, and arterial partial pressure of oxygen on the first day after surgery differed substantially (P < 0.05). Multivariate logistic regression analysis indicated that age, surgery time, history of hypertension, duration of mechanical ventilation, and intensive care unit stay were independent risk factors for central nervous system injury after TEVAR of type B aortic dissection (P < 0.05). CONCLUSION: For high-risk patients with central nervous system injury after TEVAR of type B aortic dissection, early intervention measures should be implemented to lower the risk of neurological discomfort following surgery in high-risk patients with central nervous system injury after TEVAR for type B aortic dissection.

Unraveling Phenotypic Heterogeneity in Stanford Type B Aortic Dissection Patients through Machine Learning Clustering Analysis of Cardiovascular CT Imaging.

BACKGROUND: Aortic dissection remains a life-threatening condition necessitating accurate diagnosis and timely intervention. This study aimed to unravel phenotypic heterogeneity in Stanford type B aortic dissection (TBAD) patients through machine learning clustering analysis of cardiovascular CT imaging. METHODS: Electronic medical records were collected to extract demographic and clinical features of TBAD patients. Exclusion criteria ensured homogeneity and clinical relevance of the TBAD cohort. Controls were selected based on age, comorbidity status, and imaging availability. Aortic morphological parameters were extracted from CT angiography (CTA) and subjected to k-means clustering analysis to identify distinct phenotypes. RESULTS: Clustering analysis revealed three phenotypes of TBAD patients with significant correlations to population characteristics and dissection rates. This pioneering study utilized CT-based three-dimensional reconstruction to classify high-risk individuals, demonstrating the potential of machine learning in enhancing diagnostic accuracy and personalized treatment strategies. Recent advancements in machine learning have garnered attention in cardiovascular imaging, particularly in aortic dissection research. These studies leverage various imaging modalities to extract valuable features and information from cardiovascular images, paving the way for more personalized interventions. CONCLUSIONS: This study provides insights into the phenotypic heterogeneity of TBAD patients using machine learning clustering analysis of cardiovascular CT imaging. The identified phenotypes exhibit correlations with population characteristics and dissection rates, highlighting the potential of machine learning in risk stratification and personalized management of aortic dissection. Further research in this field holds promise for improving diagnostic accuracy and treatment outcomes in aortic dissection patients.

Two-Stage Surgery Using FROZENIX Partial ET for Frozen Elephant Trunk Technique and Open Descending Aortic Replacement in a Patient With Recurrent Type B Aortic Dissection and Microscopic Polyangiitis: A Case Report.

The frozen elephant trunk (FET) technique, initially developed as a one-stage procedure to treat extensive thoracic aortic aneurysms, has since been adapted to address acute and chronic aortic dissections by closing entry tears and expanding the true lumen. It has become widely adopted due to its effectiveness in managing aortic diseases. We present the case of a 39-year-old female with microscopic polyangiitis (MPA) who developed recurrent type B aortic dissection accompanied by rapid expansion. The patient, a compromised host with multiple comorbidities such as glomerulonephritis, chronic renal failure, alveolar hemorrhage, and acute pancreatitis, required urgent surgical intervention. Given the complexity of her condition and the high risks associated with direct surgery, a staged approach was selected. The first stage involved using a novel FET prosthesis, the FROZENIX Partial ET (FPET), inserted via median sternotomy, followed by a left thoracotomy for non-deep hypothermic circulatory arrest (non-DHCA) descending aortic replacement. The surgery led to favorable outcomes without any major complications or sequelae. FPET offers distinct advantages in this complex scenario. Its design features a 2 cm stent-free distal section, which reduces the risk of distal stent graft-induced new entries (dSINEs) and simplifies anastomosis during the second stage of surgery. For patients with severe comorbidities and anatomical challenges that make the thoracic endovascular aortic repair (TEVAR) unsuitable, a staged open surgical approach is a viable alternative, mitigating the risks linked to DHCA. This case underscores the utility of a staged surgical approach using FPET in managing complicated chronic type B aortic dissection in patients with significant comorbidities. The FPET prosthesis facilitates effective lesion control while minimizing the risk of dSINEs and streamlining subsequent surgical procedures, presenting a promising strategy for similar complex cases.

Development and Validation of a User Friendly Morphology Grading System (PATENT) Predicting Aortic Remodelling After Thoracic Endovascular Aortic Repair in High Risk Uncomplicated Type B Aortic Dissection.

OBJECTIVE: This study aimed to create a morphology grading system, solely based on 2D images from computed tomography angiography, to predict negative aortic remodelling (NAR) for patients with high risk uncomplicated type B aortic dissection (TBAD) after thoracic endovascular aortic repair (TEVAR). METHODS: This single centre retrospective cohort study extracted and analysed consecutive patients diagnosed with high risk uncomplicated TBAD. Negative aortic remodelling was defined as an increase in the false lumen or total aortic diameter, or decrease in the true lumen diameter. The multivariable Cox regression model identified risk factors and a prediction model was created for two year freedom from NAR. A three category grading system, in which patients were classified into low, medium, and high risk groups, was further developed and internally validated. RESULTS: Of 351 patients included, 99 (28%) developed NAR. The median age was 52 years (interquartile range 45, 62 years) and 56 (16%) were female. The rate of two year freedom from NAR was 71% (95% CI 65 - 77%). After the multivariable Cox regression analysis, Patent false lumen, Aberrant right subclavian artery, Taper ratio, abdominal circumferential Extent, coeliac artery or reNal artery involved, and four channel dissection (Three false lumens) remained independent predictors and were included in the PATENT grading system. The risk score was statistically significantly associated with NAR (HR 1.21; 95% CI 1.14 - 1.29; p < .001). The medium and high risk groups demonstrated a higher rate of NAR (medium risk, HR 2.82; 95% CI 1.57 - 5.01; p = .001; high risk, HR 4.39; 95% CI 2.58 - 7.48; p < .001). The grading system was characterised by robust discrimination with Harrell's C index of 0.68 (95% CI 0.63 - 0.75). CONCLUSION: The PATENT grading system was characterised by good discrimination and calibration, which may serve as a clinician friendly tool to aid risk stratification for TBAD patients after TEVAR.

Multilayer Flow Modulator Stent for Aortic Pathology: A Meta-Analysis and Additional Data from a Single-Centre Retrospective Cohort.

Background: Thoracoabdominal aneurysms and aortic dissections are a challenge for vascular surgeons. Open surgery, fenestrated or branched endograft, and the chimney technique are not possible in some patients, because of comorbidities or anatomical restrictions. However, the multilayer flow modulator (MFM) can be implanted in some of these patients. In this systematic review, we will describe the experience with the multilayer stent. To augment the limited number of studies available, we will include a cohort of patients from our hospital. Methods: We retrieved data on all consecutive patients treated using the MFM between May 2013 and August 2020. This included patients with type B dissections and thoracoabdominal or thoracic aneurysms who were unfit for open surgery. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We included all the studies that used the MFM in the aortic segment. Single-arm meta-analyses were performed using OpenMeta (Brown University, Providence, RI, USA). Results: A total of 37 patients were treated in our hospital during the study period. The technical success was 97.3% and the 30-day mortality was 5.4%. In 40.5% of the included patients, the instructions for use were not followed. Off-label implantation was associated with a higher aneurysm-related mortality. A total of 12 studies were included in the meta-analysis and the technical success was 97.8%. In 68.5%, the aneurysm sack or false lumen remained perfused, 97% of all the covered side branches remained patent. After a follow-up period of 1 year, five patients in the meta-analysis presented with a ruptured aneurysm. Conclusions: The overall quality of evidence is poor because long-term results are lacking, patients are frequently lost during follow-up and all the studies were non-comparative. Our retrospective study suggests a relatively low incidence of perioperative complications, although there was a high incidence of persistent perfusion in the aneurysm sac (102 of 149 patients). The risk of rupture at the 1-year follow-up was 2.1%.

Risk prediction and prognostic analysis of post-implantation syndrome after thoracic endovascular aortic repair.

This study aimed to establish a predictive model for the risk of post-thoracic endovascular aortic repair (TEVAR) post-implantation syndrome (PIS) in type B aortic dissection (TBAD) patients, assisting clinical physicians in early risk stratification and decision management for high-risk PIS patients. This study retrospectively analyzed the clinical data of 547 consecutive TBAD patients who underwent TEVAR treatment at our hospital. Feature variables were selected through LASSO regression and logistic regression analysis to construct a nomogram predictive model, and the model's performance was evaluated. The optimal cutoff value for the PIS risk nomogram score was calculated through receiver operating characteristic (ROC) curve analysis, further dividing patients into high-risk group (HRG) and low-risk group (LRG), and comparing the short to midterm postoperative outcomes between the two groups. In the end, a total of 158 cases (28.9%) experienced PIS. Through LASSO regression analysis and multivariable logistic regression analysis, variables including age, emergency surgery, operative time, contrast medium volume, and number of main prosthesis stents were selected to construct the nomogram predictive model. The model achieved an area under the curve (AUC) of 0.86 in the training set and 0.82 in the test set. Results from calibration curve, decision curve analysis (DCA) and clinical impact curve (CIC) demonstrated that the predictive model exhibited good performance and clinical utility. Furthermore, after comparing the postoperative outcomes of HRG and LRG patients, we found that the incidence of postoperative PIS significantly increased in HRG patients. The duration of ICU stay and mechanical assistance time was prolonged, and the incidence of postoperative type II entry flow and acute kidney injury (AKI) was higher. The risk of aortic-related adverse events (ARAEs) and major adverse events (MAEs) at the first and twelfth months of follow-up also significantly increased. However, there was no significant difference in the mortality rate during hospitalization. This study established a nomogram model for predicting the risk of PIS in patients with TBAD undergoing TEVAR. It serves as a practical tool to assist clinicians in early risk stratification and decision-making management for patients.

Management and outcomes of aortic dissection type B in late pregnancy: A retrospective case series.

OBJECTIVE: Pregnancy complicated with type B aortic dissection is a rare but devastating condition. Guidelines for managing this condition are lacking. We present our observation and experiences in managing five pregnant women with complicated type B aortic dissection in the second or third trimesters, aiming to gain insights that can aid in proposing an appropriate management strategy. DESIGN: A retrospective study. SETTING: Zhongnan Hospital of Wuhan University. POPULATION: Pregnant women with complicated type B aortic dissection. METHODS: Clinical data of five pregnant women with complicated type B aortic dissection admitted to Zhongnan Hospital of Wuhan University from January 2022 to June 2023 were collected. The clinical characteristics, treatment strategies, and corresponding maternal and infant outcomes were retrospectively analysed. MAIN OUTCOME MEASURES: Survival of mothers and foetuses. RESULTS: All five study participants were diagnosed with complicated type B aortic dissection by computed tomography angiography (CTA). The range of gestational weeks at admission was 27 weeks + 3 days to 36 weeks + 6 days. The first patient, planning a caesarean section (C-section) followed by thoracic endovascular aortic repair (TEVAR), died of aortic dissection rupture during C-section. Her neonate was successfully rescued. In contrast, the remaining four patients who underwent TEVAR first survived. Among them, three patients underwent single-stage aortic repair and delivery, while one patient received C-section 31 days after TEVAR. Three preterm live births were recorded among these surviving mothers. Neonatal death occurred in one case with a gestational age of 29 weeks + 5 days, who had foetal distress before surgery. During the follow-up period of up to 3 months, no maternal or infant death occurred. No device-related or systemic complications were observed in the surviving mothers after discharge. Routine physical examinations of the four live births showed no abnormalities. CONCLUSIONS: For pregnant women with thoracic back pain and high suspicion of aortic dissection, CTA should be conducted promptly to prevent missed or delayed diagnosis. Maternal survival should be prioritised over foetal outcome once diagnosed. TEVAR was demonstrated to be safe and feasible for such patients. For women with complicated type B aortic dissection in late pregnancy, TEVAR followed by C-section may be a promising treatment strategy.

Comparison of chimney technique and single-branched stent graft in a cohort of patients with type B aortic dissections: a retrospective cohort study.

Background: Single-branched stent grafts and the chimney technique are widely used in the treatment of type B aortic dissection (TBAD). The main objective of this study was to compare the outcomes of single-branched stent grafts and the chimney technique in the treatment of TBAD. Methods: From January 2019 to December 2021, the retrospective cohort study contained a cohort of 91 patients with TBAD undergoing thoracic endovascular aortic repair (TEVAR) using single-branched stent grafts and the chimney technique. Group A included 55 patients treated with single-branched covered stents, and Group B included 36 patients treated with the chimney technique. We compared the effects of the procedures on peri-/post-operative outcomes between the two groups. The primary endpoint is clinical death, and the secondary endpoints include the patency of branch stents, the incidence of cerebral infarction, false lumen thrombosis, and the proportion of paraplegia. Results: For the baseline data, the two groups of patients show no differences in terms of age, gender, and associated symptoms. All procedures were successfully performed in both groups. The median follow-up period was 17.6 months (range, 10-34 months). During TEVAR, 5 (9.1%) type I endoleaks occurred in group A, and 11 (30.6%) occurred in group B (P<0.05). During follow-up, there were 2 cases (3.6%) of paraplegia and 1 case (1.8%) of cerebral infarction in Group A, while Group B had 1 case (2.8%) of paraplegia. Three patients in group B reported retrograde type A aortic dissection (RTAD), and 1 of them died (2.8%); however, there were no RTAD cases in group A. Complete thrombosis of the false lumen in the thoracic aorta was observed in 45.5% (25/55) of patients in group A and in 41.7% (15/36) in group B (P=0.72). No significant difference in the thrombosis-volume ratio in the whole false lumen was found during follow-up between group A (81.0%±2.9%) and group B (81.8%±2.6%; P=0.23). Conclusions: Branched stent grafts can be used in cases with insufficient proximal landing zones and reduce the occurrence of type 1 endoleak compared to the chimney technique. This may help to prevent RTAD. Further research, including more cases and longer follow-up periods, is needed to substantiate these results.

Aortic mineralization triggers the risk of acute type B aortic dissection.

BACKGROUND AND AIMS: The role of aortic mineralization in the pathogenesis of acute type B aortic dissection (TBAD) is unclear. Whether thoracic aortic calcification (TAC) and circulating alkaline phosphatase (ALP) activity are associated with acute TBAD risk remains elusive. METHODS: Observational and Mendelian randomization (MR) studies were conducted sequentially. Using propensity score matching (1:1) by age and sex, patients with acute TBAD (n = 125) were compared with control patients (n = 125). Qualitative (score) and quantitative (volume) analyses of the TAC burden on different thoracic aortic segments were conducted using non-enhanced computed tomography. Univariate and multivariate analyses were used to identify significant independent risk factors for TBAD and TAC burden, respectively. MR was finally used to determine the causal relationship between elevated ALP activity and TBAD risk. RESULTS: The qualitative and quantitative analyses revealed that TAC burden was significantly higher in the TBAD group, except for in the ascending aortic segment (both p < 0.05). Preoperative circulating ALP was significantly elevated in the TBAD group (p < 0.001). The elevated TAC burden score on the descending thoracic aortic segment (odds ratio [OR] 3.31, 95% confidence interval [CI] 1.31-8.37) and increased ALP activity (OR 1.03, 95% CI 1.01-1.06) was independently associated with TBAD risk. Interestingly, ALP was significantly positively associated with TAC burden, and MR analyses confirmed that ALP genetically predicted TBAD risk. CONCLUSIONS: Elevated ALP may trigger TBAD risk via the increased volume of TAC. Aortic mineralization may not protect the aorta itself.

Acute Coronary Syndrome and Acute Abdomen Suspected for Type B Aortic Dissection in an Elderly Woman.

Being an uncommon and challenging disorder, acute aortic dissection (AAD) can have fatal outcomes in the event of missed diagnosis or treatment delay. AAD could easily be misdiagnosed, as symptoms usually mimic other common clinical syndromes showing up in Accident and Emergency (A&E), including acute coronary syndrome (ACS), pericarditis, pulmonary embolism, acute abdomen, musculoskeletal pain, as well as presenting as heart failure, stroke, syncope, and absent peripheral pulses. We present a case of a 77-year-old female who presented to the medical decision unit with acute-onset chest, back, and abdominal pain that occurred on standing for six hours She was thought initially to have acute coronary syndrome based on electrocardiography (ECG) changes, troponin, a normal chest X-ray, and no blood pressure discrepancies in upper extremities. Due to worsening abdominal pain and a previous history of a perforated diverticulum, contrast computed tomography (CT) of the abdomen was arranged and this showed acute type B aortic dissection. By the time the CT was performed, the patient had been in hospital for 16 hours, almost 22 hours from the onset of pain.

Clinical outcomes and aortic remodeling after Castor single-branched stent-graft implantation for type B aortic dissections involving left subclavian artery.

Background: The left subclavian artery (LSA) can be intentionally covered by a stent graft to acquire adequate landing zones for a proximal entry tear near the LSA during thoracic endovascular aortic repair (TEVAR). The Castor single-branched stent graft is designed to treat type B aortic dissection (TBAD) to retain the LSA during TEVAR. This study investigates clinical outcomes, aortic remodeling, and abdominal aortic perfusion patterns after TEVAR with the novel Castor device. Methods: From November 2020 to June 2023, 29 patients with TBAD involving the LSA were treated with the Castor single-branched stent graft. In-hospital clinical outcome and aortic computed tomography angiography (CTA) data were analyzed. CTA was performed preoperatively and at follow-up to observe stent morphology; branch patency; endoleak; change in true lumen (TL), false lumen (FL), and transaortic diameters; and abdominal aortic branch perfusion pattern. Results: The technical success rate was 96.6%. One failure was that the branch section did not completely enter the LSA and the main body migrated distally. No in-hospital mortality, paraplegia, or stroke occurred. During follow-up, one type Ib endoleak, four distal new entry tears, and one recurrent type A dissection arose from a new entry tear at the ascending aorta, no stent migration was observed, and the branch patency rate was 100%. At the thoracic aorta, TL diameters significantly increased, FL diameters markedly decreased, and FL was partially or completely thrombosed in most patients at follow-up. At the abdominal aorta, we observed 33.3% of TL growth and 66.7% of TL stabilization or shrinkage. The initial TL ratio at iliac bifurcation negatively predicted abdominal TL growth after TEVAR with a cutoff of 21.0%. Of the 102 abdominal aortic branches, 94.1% of the branches showed no change in perfusion pattern, 3.9% of the branches had an increased TL perfusion, and 2.0% of the branches had an increased FL contribution. Conclusion: The Castor unibody single-branched stent graft offers an efficient endovascular treatment for TBAD involving the LSA. TEVAR with the Castor device effectively induced thoracic FL thrombosis and thoracic TL enlargement and resulted in abdominal TL growth when the initial TL ratio at iliac bifurcation is less than 21.0%. Abdominal aortic branch perfusion patterns remain relatively stable after TEVAR with the Castor stent graft.

What is the Optimal Proximal Landing Zone of the Stent Graft in Treatment of Aortic Type B Dissection?

PURPOSE: Retrograde type A aortic dissection (RTAD) represents a serious complication of endovascular treatment for type B aortic dissection (TBAD). To avoid RTAD, it is recommended to land the proximal end of the stent graft in a non-dissected aortic segment. In this study, we investigated whether landing in the dissection area increased the number of events at the proximal site. METHODS: We conducted a retrospective review of endovascular treatments for TBAD at a single institution between 2009 and 2022. Patients were divided into two groups: group A, with a proximal landing zone entirely within the dissected area, and group B, with the proximal extent of the seal zone in the non-dissected area. We evaluated the occurrence of proximal events, including RTAD, and examined long-term outcomes to assess the validity of landing in the dissection area. RESULTS: The study included eighty-nine patients who underwent endovascular treatment for TBAD. New intimal tears in the proximal landing site occurred in 3 cases (3.4%), with 1 case (2%) in group A and 2 cases (5.1%) in group B, showing no significant difference. Among the three cases, one (1.1%) in group B with zone 2 landing resulted in RTAD. At 60 months, the overall survival was 85%, and freedom from aorta-related mortality was 88%, with no significant difference between the groups. CONCLUSION: Even if the proximal landing is in a dissected area, a treatment strategy performed in zone 3 without proximal landing in zone 2, seeking a non-dissected area, can still provide sufficient therapeutic effects. Level of Evidence 3 Retrospective single-center cohort analysis.

Volumetric analysis of acute uncomplicated type B aortic dissection using an automated deep learning aortic zone segmentation model.

BACKGROUND: Machine learning techniques have shown excellent performance in three-dimensional medical image analysis, but have not been applied to acute uncomplicated type B aortic dissection (auTBAD) using Society for Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS)-defined aortic zones. The purpose of this study was to establish a trained, automatic machine learning aortic zone segmentation model to facilitate performance of an aortic zone volumetric comparison between patients with auTBAD based on the rate of aortic growth. METHODS: Patients with auTBAD and serial imaging were identified. For each patient, imaging characteristics from two computed tomography (CT) scans were analyzed: (1) the baseline CT angiography (CTA) at the index admission and (2) either the most recent surveillance CTA or the most recent CTA before an aortic intervention. Patients were stratified into two comparative groups based on aortic growth: rapid growth (diameter increase of ≥5 mm/year) and no or slow growth (diameter increase of <5 mm/year). Deidentified images were imported into an open source software package for medical image analysis and images were annotated based on SVS/STS criteria for aortic zones. Our model was trained using four-fold cross-validation. The segmentation output was used to calculate aortic zone volumes from each imaging study. RESULTS: Of 59 patients identified for inclusion, rapid growth was observed in 33 patients (56%) and no or slow growth was observed in 26 patients (44%). There were no differences in baseline demographics, comorbidities, admission mean arterial pressure, number of discharge antihypertensives, or high-risk imaging characteristics between groups (P > .05 for all). Median duration between baseline and interval CT was 1.07 years (interquartile range [IQR], 0.38-2.57). Postdischarge aortic intervention was performed in 13 patients (22%) at a mean of 1.5 ± 1.2 years, with no difference between the groups (P > .05). Among all patients, the largest relative percent increases in zone volumes over time were found in zone 4 (13.9%; IQR, -6.82 to 35.1) and zone 5 (13.4%; IQR, -7.78 to 37.9). There were no differences in baseline zone volumes between groups (P > .05 for all). The average Dice coefficient, a performance measure of the model output, was 0.73. Performance was best in zone 5 (0.84) and zone 9 (0.91). CONCLUSIONS: We describe an automatic deep learning segmentation model incorporating SVS-defined aortic zones. The open source, trained model demonstrates concordance to the manually segmented aortas with the strongest performance in zones 5 and 9, providing a framework for further clinical applications. In our limited sample, there were no differences in baseline aortic zone volumes between patients with rapid growth and patients with no or slow growth.

Interventions in Acute or Subacute Phase for Type B Aortic Dissection.

The treatment strategy for acute and subacute Stanford type B aortic dissection has changed significantly since the advent of thoracic endovascular aortic repair (TEVAR). Indication for invasive treatment: In addition to the conventional complicated cases (rupture or malperfusion case), the indication for invasive treatment now includes cases with refractory hypertension, persistent or recurrent pain, large aortic diameter, and other conditions that are considered to have a poor prognosis with conservative treatment. Treatment methods: TEVAR is the first choice for acute, subacute, and early chronic-stage treatment, and when this is not possible, other techniques (fenestration and graft replacement) are chosen. Treatment timing: The timing of invasive treatment should be emergent in life-threatening conditions (for rupture or malperfusion case) and immediate in symptomatic cases, while in other cases, preemptive TEVAR is considered appropriate on a scheduled timing within 6 months of onset. (This is a translation of Jpn J Vasc Surg 2023; 32: 157-163.).

Preemptive treatment in the acute and early subacute phase of uncomplicated type B aortic dissections with poor prognosis factors.

Objective: Due to its favorable outcome regarding late morbidity and mortality, thoracic endovascular repair (TEVAR) is becoming more popular for uncomplicated type B aortic dissection (TBAD). This study aimed to compare preemptive endovascular treatment and optimal medical treatment (OMT) and OMT alone in patients presenting uncomplicated TBAD with predictors of aortic progression. Design: Retrospective multicenter study. Methods: We analyzed patients with uncomplicated TBAD and risk factors of progression in two French academic centers. Aortic events [defined as aortic-related (re)intervention or aortic-related death after initial hospitalization], postoperative complications, non-aortic events, and radiologic aortic progression and remodeling were recorded and analyzed. Analysis was performed on an intention-to-treat basis. Results: Between 2011 and 2021, preemptive endovascular procedures at the acute and early subacute phase (<30 days) were performed on 24 patients (group 1) and OMT alone on 26 patients (group 2). With a mean follow-up of 38.08 ± 24.53 months, aortic events occurred in 20.83% of patients from group 1 and 61.54% of patients from group 2 (p < .001). No patient presented aortic-related death during follow-up. There were no differences in postoperative events (p = 1.00) and non-aortic events (p = 1.00). OMT patients had significantly more aneurysmal progression of the thoracic aorta (p < .001) and maximal aortic diameter (p < .001). Aortic remodeling was found in 91.67% of patients in group 1 and 42.31% of patients in group 2 (p < .001). A subgroup analysis of patients in group 1 showed that patients treated with preemptive TEVAR and STABILISE had reduced maximum aortic diameters at the 1-year (p = .010) and last follow-up (p = .030) compared to those in patients treated with preemptive TEVAR alone. Conclusion: Preemptive treatment of uncomplicated TBAD with risk factors of progression reduces the risk of long-term aortic events. Over 60% of medically treated patients will require intervention during follow-up, with no benefit in terms of postoperative events. Even after surgical treatment, patients in the OMT group had significantly more aneurysmal progression, along with poorer aortic remodeling.