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.

Haemodynamic effects of non-Newtonian fluid blood on the abdominal aorta before and after double tear rupture.

OBJECTIVES: Intimal tears caused by aortic dissection can weaken the arterial wall and lead to aortic aneurysms. However, the effect of different tear states on the blood flow behaviour remains complex. This study uses a novel approach that combines numerical haemodynamic simulation with in vitro experiments to elucidate the effect of arterial dissection rupture on the complex blood flow state within the abdominal aneurysm and the endogenous causes of end-organ malperfusion. MATERIALS AND METHODS: Based on the CT imaging data and clinical physiological parameters, the overall arterial models including aortic dissection and aneurysm with single tear and double tear were established, and the turbulence behaviours and haemodynamic characteristics of arterial dissection and aneurysm under different blood pressures were simulated by using non-Newtonian flow fluids with the pulsatile blood flow rate of the clinical patients as a cycle, and the results of the numerical simulation were verified by in vitro simulation experiments. RESULTS: Hemodynamic simulations revealed that the aneurysm and single-tear false lumen generated a maximum pressure of 320.591 mmHg, 267 % over the 120 mmHg criterion. The pressure differential generates reflux, leading to a WSS of 2247.9 Pa at the TL inlet and blood flow velocities of up to 6.41 m/s inducing extend of the inlet. DTD Medium FL instantaneous WP above 120 mmHg Standard 151 % Additionally, there was 82.5 % higher flow in the right iliac aorta than in the left iliac aorta, which triggered malperfusion. Thrombus was accumulated distal to the tear and turbulence. These results are consistent with the findings of the in vitro experiments. CONCLUSIONS: This study reveals the haemodynamic mechanisms by which aortic dissection induces aortic aneurysms to produce different risk states. This will contribute to in vitro simulation studies as a new fulcrum in the process of moving from numerical simulation to clinical trials.

Acute Aortic Dissection Presenting as Rectal Tenesmus.

BACKGROUND Acute aortic dissection (AAD) is a life-threatening medical emergency that requires a high index of clinical suspicion to be diagnosed promptly. The variability in the clinical presentation of AAD has historically made it difficult to identify in the acute setting. There remains significant inter-physician variability in the use of imaging. The median time to diagnosis in the Emergency Department is over 4 h and AAD has a mortality rate of 68% when diagnosis is delayed by over 48 h after onset of symptoms. CASE REPORT We discuss a case of a 69-year-old woman presenting with gastrointestinal symptoms in the Emergency Department who ultimately was found to have AAD. The patient had delayed presentation by 12 h due to misattribution of her rectal tenesmus to irritable bowel syndrome. However, after a thorough history and physical exam, the Emergency Medicine physician appropriately risk-stratified the patient and correctly diagnosed her with a Stanford Type A aortic dissection using a computed tomography study of the chest, abdomen, and pelvis with intravenous contrast. CONCLUSIONS AAD is an uncommon disease often requiring emergency intervention. We summarize the research and scoring systems and discuss the physical exam findings, comorbidities, imaging modalities, and risk stratification tools. Although imperfect, the Aortic Dissection Detection Risk Score with the addition of a D-dimer test is currently the best-validated tool and should be an important part of clinical decision making prior to performing computed tomography imaging.

Bifurcation dissecting aneurysm: tips and tricks to differentiate from saccular aneurysm.

Bifurcations are a common site for saccular aneurysms, but rarely can be a site for dissecting aneurysms. Identification of these aneurysms is extremely important because the management plan depends on it. We describe a rare case of a ruptured dissecting aneurysm at the right ICA bifurcation in a pre-teen child which posed a diagnostic dilemma but ultimately was successfully managed with flow diversion.

Intraoperative Aortic Dissection in a Case of Aneurysmal Dilatation of the Ascending Aorta Posted for Surgery.

ABSTRACT: Intraoperative aortic dissection is a life-threatening emergency. The prognosis of patients with aortic dissection has markedly improved in recent years due to prompt diagnosis and the institution of effective medical and surgical therapy. Transesophageal echocardiography (TEE) is helpful in the evaluation of this life-threatening disorder.

An efficient procedure for the blood flow computer simulation of patient-specific aortic dissections.

In this work we present a novel methodology for the numerical simulation of patient-specific aortic dissections. Our proposal, which targets the seamless virtual prototyping of customized scenarios, combines an innovative two-step segmentation procedure with a CutFEM technique capable of dealing with thin-walled bodies such as the intimal flap. First, we generate the fluid mesh from the outer aortic wall disregarding the intimal flap, similarly to what would be done in a healthy aorta. Second, we create a surface mesh from the approximate midline of the intimal flap. This approach allows us to decouple the segmentation of the fluid volume from that of the intimal flap, thereby bypassing the need to create a volumetric mesh around a thin-walled body, an operation widely known to be complex and error-prone. Once the two meshes are obtained, the original configuration of the dissection into true and false lumen is recovered by embedding the surface mesh into the volumetric one and calculating a level set function that implicitly represents the intimal flap in terms of the volumetric mesh entities. We then leverage the capabilities of unfitted mesh methods, specifically relying on a CutFEM technique tailored for thin-walled bodies, to impose the wall boundary conditions over the embedded intimal flap. We tested the method by simulating the flow in four patient-specific aortic dissections, all involving intricate geometrical patterns. In all cases, the preprocess is greatly simplified with no impact on the computational times. Additionally, the obtained results are consistent with clinical evidence and previous research.

A 12-year Retrospective Cohort Study of Point-of-care Ultrasound and Aortic Dissection Risk Score in Type A Aortic Dissection.

BACKGROUND: Aortic dissection (AD) is a vascular emergency with time-dependent mortality. Point-of-care ultrasound (POCUS) and AD risk score (ADRS) have been proposed as diagnostic tools to risk stratify patients and reduce time to diagnosis. STUDY OBJECTIVE: We evaluate POCUS findings and ADRS in a retrospective cohort of patients with known type A AD. The objective of this study is to describe the prevalence of POCUS findings and ADRS in this population. METHODS: This is a retrospective cohort study of patients with acute type A AD as confirmed on computed tomography scan over a 12-year period from 2008 to 2020, with a subgroup analysis of patients who received POCUS in the emergency department. ADRS was calculated and POCUS findings were reviewed. Descriptive statistics were used to describe the distribution of POCUS findings. RESULTS: Ninety-one patients met inclusion criteria. POCUS was performed in 41 but only 35 had images of adequate quality for inclusion. Of the POCUS images available, 30/35 (86%) patients had a POCUS finding consistent with dissection and 5/35 (14%) had no findings on POCUS. Twelve percent (11/91) of patients had ADRS = 0. Two patients with ADRS = 0 received POCUS, and one patient had no findings on POCUS. CONCLUSION: Although POCUS provides rapid information in the diagnosis of type A AD, 14% of patients with images available for review had no findings on POCUS. Of the whole cohort, 12% had an ADRS = 0. Further studies are needed to identify an optimal diagnostic pathway for this catastrophic disease.

[An unusual... dissection]. / Una insolita... dissezione.

Pulmonary artery dissection is a rare and fatal disease. Diagnosis is mainly made during autopsy because most patients die suddenly due to pulmonary artery dissection in the pericardium resulting in pericardial tamponade. The optimum management is not clearly defined because of the paucity of cases in the literature. We describe the case of an 81-year-old man, affected by rheumatoid arthritis and with history of aortic valve replacement surgery, who attended an emergency department for non-specific symptoms, started complaining of chest pain rapidly deteriorated into cardiac shock. Computed tomography scan, performed on suspicion of an acute aortic pathology and/or a pulmonary embolism, allowed the identification of pulmonary artery dissection associated with aorto-pulmonary fistula. Despite early diagnosis in the emergency department, the outcome was unfortunately fatal.

Acute aortic dissection during scuba diving.

A 60-year-old man with hypertension and dyslipidemia complained of chest pain upon ascending from a maximum depth of 27 meters while diving. After reaching the shore, his chest pain persisted, and he called an ambulance. When a physician checked him on the doctor's helicopter, his electrocardiogram (ECG) was normal, and there were no bubbles in his inferior vena cava or heart on a portable ultrasound examination. The physician still suspected that he had acute coronary syndrome instead of decompression illness; therefore, he was transported to our hospital. After arrival at the hospital, standard cardiac echography showed a flap in the ascending aorta. Immediate enhanced computed tomography revealed Stanford type A aortic dissection. The patient obtained a survival outcome after emergency surgery. To our knowledge, this is the first reported case of aortic dissection potentially associated with scuba diving. It highlights the importance of considering aortic dissection in patients with sudden-onset chest pain during physical activity. In addition, this serves as a reminder that symptoms during scuba diving are not always related to decompression. This report also suggests the usefulness of on-site ultrasound for the differential diagnosis of decompression sickness from endogenous diseases that induce chest pain. Further clinical studies of this management approach are warranted.

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.

Multiple aortic root pseudoaneurysms with dissecting aneurysm of the interventricular septum diagnosed by multimodal imaging.

Aortic root pseudoaneurysm is a devastating complication post aortic valve replacement with a high mortality rate. And dissecting aneurysm into the interventricular septum is a rare variant of aortic root pseudoaneurysm, which is scarcely reported. Multimodal imaging is of great value in its diagnosis and differential diagnosis.

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.

Natural history and long-term outcomes of medically managed Type B intramural hematoma.

OBJECTIVE: Type B intramural hematoma (IMH) is often managed medically, yet may progress to dissection, aneurysmal dilation, or rupture. The aim of this study was to report the natural history of medically managed Type B IMH, and factors associated with progression. METHODS: We reviewed patients with medically managed Type B IMH between January 1995 to December 2022 at a single center. Any patients with immediate surgical or endovascular intervention were excluded. Demographic profiles, comorbidities, imaging, and follow-up details were reviewed. Patients were divided into two groups: Group 1 had isolated IMH, and Group 2 had IMH along with aneurysm or dissection at the time of presentation. On follow-up, progression was defined as degeneration to aneurysm/dissection or increase in the thickness of IMH in Group 1. In Group 2, progression was an increase in the size of aneurysm or development of new dissection. RESULTS: Of 104 patients with Type B IMH during the study period, 92 were medically managed. The median age was 77 years, and 45 (48.9%) were females. Comorbidities included hypertension (83.7%), hypercholesterolemia (44.6%), and active smoking (47.8%). Mean Society for Vascular Surger comorbidity score was 6.3. Mean IMH thickness and aortic diameter at presentation were 8.9 mm and 38.3 mm, respectively. Median follow-up was 55 months. Overall survival at 1 year and 5 years was 85.8% and 61.9%, respectively. During follow-up, 19 patients (20.7%) required intervention, more common in Group 2 (Group 1, 8/66; 12.3% vs Group 2, 11/26; 42.3%; P = .001). This resulted in higher freedom from intervention in Group 1 at 1 year (93.5% vs 62.7%) and 5 years (87.5% vs 51.1%; P < .001). Indication for intervention was dissection (n = 4), aneurysm (n = 12), and progression of IMH (n = 3). In Group 1, progression was seen in 25 (37.9%), three (4.5%) remained stable, 29 (43.9%) had complete resolution of IMH, and nine patients were lost to follow-up. In Group 2, 11 patients (42.3%) had progression, seven (26.9%) remained stable, and eight were lost to follow-up. IMH thickness at presentation >7.2 mm is associated with both increased odds of progression (odds ratio, 3.3; 95% confidence interval, 1.2-11.1; P = .03) and intervention (odds ratio, 5.5; 95% confidence interval, 1.3-36.9; P = .03) during the follow-up. CONCLUSIONS: Although many patients with Type B IMH managed medically stabilize or regress, progression or need for intervention can occur in up to 40% of cases. This is associated with the presence of aneurysm, dissection, and IMH thickness. Long-term follow-up is mandatory as late interventions occur, particularly for higher risk patients.

Postdissection aortic aneurysm sac enlargement after fenestrated and branched endovascular aortic aneurysm repair.

OBJECTIVES: Aneurysm sac changes after fenestrated-branched endovascular aneurysm repair (FBEVAR) for postdissection thoracoabdominal aortic aneurysms (PD-TAAs) are poorly understood. Partial thrombosis of the false lumen and endoleaks may impair sac regression. To characterize sac changes after FBEVAR for PD-TAAs, this study examined midterm results and predictors for sac enlargement. METHODS: FBEVARs performed for PD-TAAs in 10 physician-sponsored investigational device exemption studies from 2008 to 2023 were analyzed. The maximum aortic aneurysm diameter was compared between the 30-day computed tomography angiogram and follow-up imaging studies. Aneurysm sac enlargement was defined as an increase in diameter of ≥5 mm. Kaplan-Meier curves and Cox regression were used to evaluate sac enlargement and midterm FBEVAR outcomes. RESULTS: Among 3296 FBEVARs, 290 patients (72.4% male; median age, 68.4 years) were treated for PD-TAAs. Most aneurysms treated were extent II (72%) and III (12%). Mean aneurysm diameter was 66.5 ± 11.2 mm. Mortality at 30 days was 1.4%. At a mean follow-up of 2.9 ± 1.9 years, at least one follow-up imaging study revealed sac enlargement in 43 patients (15%), sac regression in 115 patients (40%), and neither enlargement nor regression in 137 (47%); 5 (2%) demonstrated both expansion and regression during follow-up. Freedom from aneurysm sac enlargement was 93%, 82%, and 80% at 1, 3, and 5 years, respectively. Overall, endoleaks were detected in 27 patients (63%) with sac enlargement and 143 patients (58%) without enlargement (P = .54). Sac enlargement was significantly more frequent among older patients (mean age at the index procedure, 70.2 ± 8.9 years vs 66.5 ± 11 years; P = .04) and those with type II endoleaks at 1 year (74% vs 52%; P = .031). Cox regression revealed age >70 years at baseline (hazard ratio [HR], 2.146; 95% confidence interval [CI], 1.167-3.944; P = .010) and presence of type II endoleak at 1 year (HR, 2.25; 95% CI, 1.07-4.79; P = .032) were independent predictors of sac enlargement. Patient survival was 92%, 81%, and 68% at 1, 3, and 5 years, respectively. Cumulative target vessel instability was 7%, and aneurysm-related mortality was 2% at 5 years. At least 42% of patients required secondary interventions. Sac enlargement did not affect patient survival. CONCLUSIONS: Aneurysm sac enlargement occurs in 15% of patients after FBEVAR for PD-TAAs. Elderly patients (>70 years at baseline) and those with type II endoleaks at 1 year may need closer monitoring and secondary interventions to prevent sac enlargement. Despite sac enlargement in some patients, aneurysm-related mortality at 5 years remains low and overall survival was not associated with sac enlargement.

A single-center experience of type B aortic intramural hematoma.

OBJECTIVE: The outcomes of the best medical treatment (BMT) and intervention treatment (INT) in a single-center experience were reported in type B intramural hematoma (IMH). METHODS: From February 2015 to February 2021, a total of 195 consecutive patients with type B IMH were enrolled in the study. The primary end point was mortality, and the secondary end points included clinical and imaging outcomes. The clinical outcomes were aortic-related death, retrograde type A aortic dissection, stent graft-induced new entry tear, endoleak, and reintervention. The imaging outcome was evaluated through the latest follow-up computed tomography angiography, which included aortic rupture, aortic dissection, aortic aneurysm, rapid growth of aortic diameter, newly developed or enlarged penetrating aortic ulcer or ulcer-like projection (ULP) and increased aortic wall thickness. Kaplan-Meier curves were used to assess the association between different treatments. RESULTS: Among the enrolled patients, 115 received BMT, and 80 received INT. There was no significant difference in early (1.7% vs 2.5%; P = 1.00) and midterm all-cause death (8.3% vs 5.2%; P = .42) between the BMT and INT groups. However, patients who underwent INT were at risk of procedure-related complications such as stent graft-induced new entry tear and endoleaks. The INT group was associated with a profound decrease in the risk of ULP, including newly developed ULP (4.3% vs 26.9%; P < .05), ULP enlargement (6.4% vs 31.3%; P < .05), and a lower proportion of high-risk ULP (10.9% vs 45.6%; P < .05). Although there was no significant difference in the incidence of IMH regression between the two groups, the maximum diameter of the descending aorta in patients receiving INT was larger compared with those treated with BMT. CONCLUSIONS: Based on our limited experience, patients with type B IMH treated with BMT or INT shared similar midterm clinical outcome. Patients who underwent INT may have a decreased risk of ULPs, but a higher risk of procedure-related events and patients on BMT should be closely monitored for ULP progression.