Life-threatening Aortic Disease Research Articles

Automatic Segmentation of Type A Aortic Dissection on Computed Tomography Images Using Deep Learning Approach.

Type A aortic dissection (TAAD) is a life-threatening aortic disease. The tear involves the ascending aorta and progresses into the separation of the layers of the aortic wall and the occurrence of a false lumen. Accurate segmentation of TAAD could provide assistance for disease assessment and guidance for clinical treatment. This study applied nnU-Net, a state-of-the-art biomedical segmentation network architecture, to segment contrast-enhanced CT images and quantify the morphological features for TAAD. CT datasets were acquired from 24 patients with TAAD. Manual segmentation and annotation of the CT images was used as the ground-truth. Two-dimensional (2D) nnU-Net and three-dimensional (3D) nnU-Net architectures with Dice- and cross entropy-based loss functions were utilized to segment the true lumen (TL), false lumen (FL), and intimal flap on the images. Four-fold cross validation was performed to evaluate the performance of the two nnU-Net architectures. Six metrics, including accuracy, precision, recall, Intersection of Union, Dice similarity coefficient (DSC), and Hausdorff distance, were calculated to evaluate the performance of the 2D and 3D nnU-Net algorithms in TAAD datasets. Aortic morphological features from both 2D and 3D nnU-Net algorithms were quantified based on the segmented results and compared. Overall, 3D nnU-Net architectures had better performance in TAAD CT datasets, with TL and FL segmentation accuracy up to 99.9%. The DSCs of TLs and FLs based on the 3D nnU-Net were 88.42% and 87.10%. For the aortic TL and FL diameters, the FL area calculated from the segmentation results of the 3D nnU-Net architecture had smaller relative errors (3.89-6.80%), compared to the 2D nnU-Net architecture (relative errors: 4.35-9.48%). The nnU-Net architectures may serve as a basis for automatic segmentation and quantification of TAAD, which could aid in rapid diagnosis, surgical planning, and subsequent biomechanical simulation of the aorta.

Targeting the smooth muscle cell KEAP1-Nrf2-STING axis with pterostilbene attenuates abdominal aortic aneurysm

BackgroundAbdominal aortic aneurysm (AAA) is a life-threatening aortic disease, and to date, there are currently no effective pharmacological treatments to address this condition. Activation of cytosolic DNA sensing adaptor stimulator of interferon genes (STING) signaling is a crucial mechanism in AAA formation. PurposeThis study investigated pterostilbene (Pt), a naturally occurring polyphenol and resveratrol analogue, as a STING inhibitor for preventing AAA. MethodsWe evaluated the effect of Pt on AAA formation in angiotensin II (AngII)-infused apolipoprotein E-deficient (ApoE−/−) mice. We used histological analysis, MMP activity measurement, western blot, and immunohistochemistry to detect AAA formation and development. We applied RNA sequencing, molecular docking, cellular thermal shift assay (CETSA) and functional studies to dissect the molecular mechanism of Pt-regulating KEAP1-Nrf2-STING signaling. We conditionally knocked down Nrf2 in vascular smooth muscle cells (VSMCs) in vivo to investigate its role in Pt-mediated protective effects on AAA. ResultsPt effectively blocked the formation of AAA in AngII-infused ApoE−/− mice. Whole transcriptome sequencing analysis revealed that nuclear factor erythroid 2-related factor 2 (Nrf2) and STING pathway in VSMCs were linked to the anti-AAA effects of pterostilbene. Mechanistically, Pt upregulated Nrf2 target genes (e.g., HO-1 and NQO1) through activation of the KEAP1/Nrf2 signaling, which restricted the immunostimulatory axis of mtDNA-STING-TBK1-NF-κB, thereby alleviating VSMC inflammation and preserving the VSMC contractile phenotype. Subsequently, molecular docking and CETSA revealed a binding mode between Pt and KEAP1/Nrf2. Intriguingly, the inhibitory effect of Pt on STING signaling and the protective role of Pt in AAA were largely abrogated by VSMC-specific Nrf2 knockdown in mice. ConclusionCollectively, naturally derived Pt shows promising efficacy for the treatment of AAA by targeting the KEAP1-Nrf2-STING axis in VSMCs.

Elongation of the proximal descending thoracic aorta and associated hemodynamics increase the risk of acute type B aortic dissection.

Acute type B aortic dissection (ATBAD) is a life-threatening aortic disease. However, little information is available on predicting and understanding of ATBAD. The study sought to explore the underlying mechanism of ATBAD by analyzing the morphological and hemodynamic characteristics related to aortic length. The length and tortuosity of the segment and the whole aorta in the ATBAD group (n= 163) and control group (n= 120) were measured. A fixed anatomic landmark from the distal of left subclavian artery (LSA) to the superior border of sixth thoracic vertebra was proposed as the proximal descending thoracic aorta (PDTA), and the dimensionless parameter, length ratio, was introduced to eliminate the individual differences. The significant morphological parameters were filtrated and the associations between parameters were investigated using statistical approaches. Furthermore, how aortic morphology influenced ATBAD was explored based on idealized aortic models and hemodynamic-related metrics. The PDTA length was significantly increased in the ATBAD group compared with the control group and had a strong positive correlation with the whole aortic length (r= 0.89). The length ratio (LR2) and tortuosity (T2) of PDTA in the ATBAD group were significantly increased (0.15 ± 0.02 vs 0.12 ± 0.02 and 1.73 ± 0.48 vs 1.50 ± 0.36; P< 0.001), and LR2 was positive correlation with T2 (r= 0.73). In receiver-operating curve analysis, the area under the curve was 0.835 for LR2 and 0.641 for T2. Low and oscillatory shear (LOS) was positive correlation with LR2, and the elevated LOS occurred in the distal of LSA. Elongation of PDTA is associated with ATBAD, and the length ratio is a novel predictor. Elongated PDTA induced more aggressive hemodynamic forces, and high LOS regions may correspond to the entry tear location. The synergy of the morphological variation and aggressive hemodynamics creates contributory conditions for ATBAD.

Regulation of matrix reloading by tumor endothelial marker 1 protects against abdominal aortic aneurysm.

Tumor endothelial marker 1 (TEM1), an activated mesenchymal cell marker, is implicated in tissue remodeling and repair. Herein, we investigated the role and therapeutic implications of TEM1 in abdominal aortic aneurysm (AAA), a potentially life-threatening aortic disease characterized by vascular inflammation and matrix turnover. Characterization of human AAA revealed increased TEM1 expression derived mainly from medial vascular smooth muscle cells (VSMCs) and adventitial fibroblasts. Bioinformatics analysis demonstrated the association between TEM1-expressing VSMCs and fibroblasts and collagen gene expression. Consistently, collagen content and TEM1 expressed by VSMCs and fibroblasts were increased during CaCl2-induced AAA formation in mice. TEM1 silencing in VSMCs and fibroblasts inhibited transforming growth factor-β1-induced phenotypic change, SMAD2 phosphorylation, and COL1A1 gene expression. Also, Tem1 deficiency reduced collagen synthesis and exacerbated CaCl2-induced AAA formation in mice without disturbing elastin destruction and inflammatory responses. In contrast, rTEM1 promoted phenotypic change and COL1A1 gene expression through SMAD2 phosphorylation in VSMCs and fibroblasts. Treatment with rTEM1 enhanced collagen synthesis, attenuated elastin fragmentation, and inhibited CaCl2-induced and angiotensin II-infused AAA formation. In summary, TEM1 in resident stromal cells regulates collagen synthesis to counteract aortic wall failure during AAA formation. Matrix integrity restored by rTEM1 treatment may hold therapeutic potential against AAA.

Causal Role for Neutrophil Elastase in Thoracic Aortic Dissection in Mice.

Thoracic aortic dissection (TAD) is a life-threatening aortic disease without effective medical treatment. Increasing evidence has suggested a role for NE (neutrophil elastase) in vascular diseases. In this study, we aimed at investigating a causal role for NE in TAD and exploring the molecular mechanisms involved. β-aminopropionitrile monofumarate was administrated in mice to induce TAD. NE deficiency mice, pharmacological inhibitor GW311616A, and adeno-associated virus-2-mediated in vivo gene transfer were applied to explore a causal role for NE and associated target gene in TAD formation. Multiple functional assays and biochemical analyses were conducted to unravel the underlying cellular and molecular mechanisms of NE in TAD. NE aortic gene expression and plasma activity was significantly increased during β-aminopropionitrile monofumarate-induced TAD and in patients with acute TAD. NE deficiency prevents β-aminopropionitrile monofumarate-induced TAD onset/development, and GW311616A administration ameliorated TAD formation/progression. Decreased levels of neutrophil extracellular traps, inflammatory cells, and MMP (matrix metalloproteinase)-2/9 were observed in NE-deficient mice. TBL1x (F-box-like/WD repeat-containing protein TBL1x) has been identified as a novel substrate and functional downstream target of NE in TAD. Loss-of-function studies revealed that NE mediated inflammatory cell transendothelial migration by modulating TBL1x-LTA4H (leukotriene A4 hydrolase) signaling and that NE regulated smooth muscle cell phenotype modulation under TAD pathological condition by regulating TBL1x-MECP2 (methyl CpG-binding protein 2) signal axis. Further mechanistic studies showed that TBL1x inhibition decreased the binding of TBL1x and HDAC3 (histone deacetylase 3) to MECP2 and LTA4H gene promoters, respectively. Finally, adeno-associated virus-2-mediated Tbl1x gene knockdown in aortic smooth muscle cells confirmed a regulatory role for TBL1x in NE-mediated TAD formation. We unravel a critical role of NE and its target TBL1x in regulating inflammatory cell migration and smooth muscle cell phenotype modulation in the context of TAD. Our findings suggest that the NE-TBL1x signal axis represents a valuable therapeutic for treating high-risk TAD patients.

Abstract 532: Deficiency of CCN3 in Smooth Muscle Cells Perturbs Vascular Homeostasis and Exacerbates Thoracic Aortic Dissection

Introduction: Thoracic aortic dissection (TAD) is a life-threatening aortic disease with a high mortality rate in the event of rupture. Key mechanisms underlying the development of TAD include extracellular matrix (ECM) degradation and vascular smooth muscle cell (SMC) reprograming. Cellular communication network factor 3 (CCN3), a matricellular protein highly expressed in SMC, exerts a myriad of context-dependent biological functions. However, its role in SMC homeostasis and in the development of TAD remains largely undefined. Methods: A single-cell sequencing (Sc-seq) dataset (GSE213740) from human aortic dissection patients was analyzed to determine the association between CCN3 expression and TAD. In newly weaned male CCN3-floxed mice harboring Myh11-driven inducible Cre, 4 consecutive tamoxifen injections induced CCN3 deletion in SMCs. Mice without Cre expression were subjected to the same procedures and were used as controls. After 1 week of washout, 4-week-old mice were given 0.5% BAPN (β-aminopropionitrile monofumarate) in their drinking water to induce TAD. Histologic and protein measurements were performed on TAD tissues from control and CCN3-SMC-KO mice. Sc-seq analysis was performed to recapitulate cell heterogeneities and transcriptome profile changes. The regulatory role of SMC-derived CCN3 in TGFβ signaling was evaluated by western blot and colocalization analyses. Results: Analysis of the human Sc-seq dataset revealed downregulation of CCN3 in aortas from patients with TAD. CCN3-positive SMCs have elevated ECM and elastin gene expression in comparison to CCN3-null SMCs. In vivo, concordant with increased mortality in CCN3-SMC-KO animals, SMC-specific deletion of CCN3 promotes BAPN-induced elastin fibers fragmentation and degradation. In vitro, SMC deficiency of CCN3 diminished TGFβ-induced elastogenesis. CCN3 binds to the TGFβ receptor on SMCs and augments TGFβ receptor phosphorylation, thereby activating Smads, upregulating SMC elastogenesis, and as a consequence, alleviates elastin fiber fragmentation and TAD development. Conclusion: CCN3 is a key determinate of SMC reprogramming and sustains vascular homeostasis. Our findings suggest a novel target for the prevention and treatment of TAD.

Targeted Inhibition of Matrix Metalloproteinase-8 Prevents Aortic Dissection in a Murine Model.

Aortic dissection (AD) is a lethal aortic pathology without effective medical treatments since the underlying pathological mechanisms responsible for AD remain elusive. Matrix metalloproteinase-8 (MMP8) has been previously identified as a key player in atherosclerosis and arterial remodeling. However, the functional role of MMP8 in AD remains largely unknown. Here, we report that an increased level of MMP8 was observed in 3-aminopropionitrile fumarate (BAPN)-induced murine AD. AD incidence and aortic elastin fragmentation were markedly reduced in MMP8-knockout mice. Importantly, pharmacologic inhibition of MMP8 significantly reduced the AD incidence and aortic elastin fragmentation. We observed less inflammatory cell accumulation, a lower level of aortic inflammation, and decreased smooth muscle cell (SMC) apoptosis in MMP8-knockout mice. In line with our previous observation that MMP8 cleaves Ang I to generate Ang II, BAPN-treated MMP8-knockout mice had increased levels of Ang I, but decreased levels of Ang II and lower blood pressure. Additionally, we observed a decreased expression level of vascular cell adhesion molecule-1 (VCAM1) and a reduced level of reactive oxygen species (ROS) in MMP8-knockout aortas. Mechanistically, our data show that the Ang II/VCAM1 signal axis is responsible for MMP8-mediated inflammatory cell invasion and transendothelial migration, while MMP8-mediated SMC inflammation and apoptosis are attributed to Ang II/ROS signaling. Finally, we observed higher levels of aortic and serum MMP8 in patients with AD. We therefore provide new insights into the molecular mechanisms underlying AD and identify MMP8 as a potential therapeutic target for this life-threatening aortic disease.

Acute renal failure after acute type A aortic dissection repair. Insidious postoperative complication with poor short- and long-term prognosis.

Acute type A aortic dissection (ATAAD) is a life-threatening aortic disease. Many systems and organs are affected by malperfusion which presents preoperatively and postoperatively. Postoperative acute renal failure after ATAAD constitutes a severe and insidious complication. Acute renal damage is observed in many patients with ATAAD preoperatively and it burdens the renal function postoperatively. Renal replacement therapy represents an additional risk factor for short-, mid-, and long-term outcomes after ATAAD repair. Brown et al.'s present study highlight the clinical significance of this complication. Also, they remind us of the importance of optimizing perioperative renal protective strategies in patients undergoing ATAAD repair.

A death due to acute aortic dissection

Acute aortic syndrome (AAS) is a term used to describe a collection of life-threatening aortic disease conditions that have similar presentations, but differ in their demographic, pathological, clinical and other characteristics. The exact number of deaths due to AAS is unknown. However studies suggest that the majority of deaths in AAS are due to acute aortic dissection. A 51-year-old male developed sudden onset chest pain while he was taking a bath in the evening. It was a sharp, tearing type chest pain, which was radiating to the left side of his neck. On admission to hospital his low blood pressure was found to be low. He suffered cardiac arrest a few minutes later and died without regaining consciousness. Post-mortem examination revealed a massive haemopericardium (600 ml). Aortic dissection was identified extending from the aortic root to the lower part of the descending abdominal aorta. The thickest point of the dissection was 1.5 cm. There was an intimal tear inferiorly. The dissection extended through the aortic arch to the descending aorta ending 1 cm above the renal artery branching point. Sections of the aorta showed cystic medial degeneration with prominent pools of mucin. Mild atheroma was seen in some sections. The presence of aortic dissection was confirmed. The cause of death was given as haemopericardium due to ruptured aortic dissection. Acute aortic dissection may mimic other cardiovascular conditions, especially ischemic cardiac events. Therefore, the clinical suspicion and a comprehensive history-taking are the key for an early diagnosis. Careful dissection of the aorta and its branches is essential when making a post-mortem diagnosis of aortic dissection. Proper histopathology examination of the aorta assisted immensely in confirming the diagnosis.

Stent grafts implantation in patients with life-threatening aortic conditions – first experience in Kyrgyz Republic

Objective: Aortic diseases remain an acute and debatable problem. Among all the aortic pathologies, the most dangerous are dynamic aneurysmal expansion, traumatic dissections and / or aneurysms, pure aortic intima dissections. Contemporary and less invasive treatment method is the stent graft implantation into aorta. This report describes the first experience of thoracic endovascular aortic repair (TEVAR) and endovascular aneurysm repair (EVAR) in the Kyrgyz Republic in consecutive patients with life-threatening aortic conditions. Methods: Nine patients, who underwent TEVAR and EVAR, were presented after all clinical examinations, echocardiography and computed tomography angiography with various life-threatening aortic diseases. Among the pathologies there were 2 (22.2%) dissections only, traumatic aneurysm 1 (11.1%), aneurysm without dissection 1 (11.1%), aneurysm with intimal dissection 5 (55.6%). Seven patients with dissection had type B (The Stanford classification). Results: TEVAR was performed in eight cases EVAR just in one. All patients reached the 6-month endpoint. None of the following, such as aneurysm expansion, aneurysm thrombosis or a functioning of false lumen at the sites of the stent graft implantation have been recorded. In addition, no further progression of the false lumen below the implantation zones was visualized. Mean diameter of stent grafts was 31.4 ± 4.8 mm and 188.9 ± 34.6 mm in length. Conclusion: This modest observation showed the effectiveness of stent grafts implantation procedures in various aortic life-threatening conditions, such as aneurysm and / or aortic intima dissection.

Diagnosis and management of Stanford B aortic dissection

Type B aortic dissection is a life-threatening aortic disease. With the development of clinical classification and diagnostic method, the mortality of type B aortic dissection has been greatly decreased. In respect of treatment, endovascular repair due to minimally invasive advantages become the first choice for the treatment of complicated type B aortic dissection. For non- complicated type B aortic dissection, endovascular repair also gradually replace drug treatment, and showed good efficacy. Open surgery is only available for patients who are not suitable for endovascular repair or repair failure or patients with connective tissue disease. Key words: Drug Therapy; Surgical procedures, operative; Diagnosis; Type B aortic dissection; Endovascular Procedures

Acute aortic syndrome.

Acute aortic syndrome (AAS) is a term used to describe a constellation of life-threatening aortic diseases that have similar presentation, but appear to have distinct demographic, clinical, pathological and survival characteristics. Many believe that the three major entities that comprise AAS: aortic dissection (AD), intramural hematoma (IMH) and penetrating aortic ulcer (PAU), make up a spectrum of aortic disease in which one entity may evolve into or coexist with another. Much of the confusion in accurately classifying an AAS is that they present with similar symptoms: typically acute onset of severe chest or back pain, and may have similar radiographic features, since the disease entities all involve injury or disruption of the medial layer of the aortic wall. The accurate diagnosis of an AAS is often made at operation. This manuscript will attempt to clarify the similarities and differences between AD, IMH and PAU of the ascending aorta and describe the challenges in distinguishing them from one another.

Update in the management of type B aortic dissection.

Stanford type B aortic dissection (TBAD) is a life-threatening aortic disease. The initial management goal is to prevent aortic rupture, propagation of the dissection, and symptoms by reducing the heart rate and blood pressure. Uncomplicated TBAD patients require prompt medical management to prevent aortic dilatation or rupture during subsequent follow-up. Complicated TBAD patients require immediate invasive management to prevent death or injury caused by rupture or malperfusion. Recent developments in diagnosis and management have reduced mortality related to TBAD considerably. In particular, the introduction of thoracic stent-grafts has shifted the management from surgical to endovascular repair, contributing to a fourfold increase in early survival in complicated TBAD. Furthermore, endovascular repair is now considered in some uncomplicated TBAD patients in addition to optimal medical therapy. For more challenging aortic dissection patients with involvement of the aortic arch, hybrid approaches, combining open and endovascular repair, have had promising results. Regardless of the chosen management strategy, strict antihypertensive control should be administered to all TBAD patients in addition to close imaging surveillance. Future developments in stent-graft design, medical therapy, surgical and hybrid techniques, imaging, and genetic screening may improve the outcomes of TBAD patients even further. We present a comprehensive review of the recommended management strategy based on current evidence in the literature.

Aortic Aneurysm: Etiopathogenesis and Clinicopathologic Correlations.

Aortic aneurysm (AA) is one of the life-threatening aortic diseases, leading to aortic rupture of any cause including atherosclerotic and non-atherosclerotic diseases. AA is diagnosed in a variable proportion of patients with dilated aorta by imaging modality. The etiopathogenesis of AA remains unclear in many aortic diseases. Furthermore, although it may be difficult to explain all phenotypes of patients even if genetic mutation could be identified in some proteins such as smooth muscle cell α-actin (ACTA2), myosin heavy chain 11 (MYH11) or SMAD3, individualized consideration of these factors in each patient is essential on the basis of clinicopathological characteristics.

Aortic Intramural Hematoma and Its Complications

> It has long been an axiom of mine that the little things are infinitely the most important.1 > > Sherlock Holmes to Dr Watson > > —Arthur Conan Doyle, > > The Adventures of Sherlock Holmes: A Case of Identity. Case Presentation: A 70-year-old woman with hypertension presents for evaluation of a single episode of nonexertional chest pain of moderate intensity, atypical for myocardial infarction. Clinical signs of acute aortic dissection and cardiac tamponade are absent. A 12-lead ECG and blood test for troponin are negative for acute myocardial infarction. M-mode transthoracic echocardiogram of the aortic root shows dense echoes anteriorly and posteriorly at the level of the aortic valve and a large pericardial effusion (Figure 1A). After discussing a diagnosis of acute aortic syndrome, she asks, “What other tests will I need to confirm the diagnosis? Will I undergo surgery?” Figure 1. A and B , M-mode echocardiogram at the level of the aortic valve. Dense echoes along right and noncoronary sinuses caused by periaortic hematoma from a perforated aortic ulcer (white arrows, A ) compared with a normal echo ( B ). C , Cardiac computed tomography angiography orthogonal view equivalent to transthoracic echocardiographic parasternal long-axis view. This view is optimized to visualize (white arrow) perforated ulcer in the ascending aorta, hemorrhagic pericardial effusion with blood collection along right and noncoronary aortic sinuses correlating with M mode echo at the level of the aortic valve. AV indicates aortic valve; LA, left atrium; LV, left ventricle; PA, pulmonary artery; and RV, right ventricle. Intramural hematoma (IMH) is a life-threatening aortic disease included within acute aortic syndrome, together with aortic dissection and penetrating aortic ulcer (PAU).2,3 IMH is a contained aortic wall hematoma with bleeding within the media but without initial intimal flap formation (Figure 2).3 Its natural history is variable; it may be reabsorbed …

Notch γ-Secretase Inhibitor Dibenzazepine Attenuates Angiotensin II-Induced Abdominal Aortic Aneurysm in ApoE Knockout Mice by Multiple Mechanisms

Abdominal aortic aneurysm (AAA) is a life-threatening aortic disease in the elderly. Activation of Notch1 pathway plays a critical role in the development of AAA, but the underlying mechanisms remain poorly understood. In the present study, we explored the mechanisms by which Notch1 activation regulates angiotensin II (Ang II)-induced AAA formation and evaluated the therapeutic potential of a new Notch γ-secretase inhibitor, dibenzazepine (DBZ), for the treatment of AAA. Apolipoprotein E knockout (Apo E−/−) mice infused for 4 weeks with Ang II (1000 ng/kg/min, IP) using osmotic mini-pumps were received an intraperitoneal injection of either vehicle or 1 mg/kg/d DBZ. Notch1 signaling was activated in AAA tissue from both Ang II-infused Apo E−/− mice and human undergoing AAA repair in vivo, with increased expression of Notch intracellular domain (NICD) and its target gene Hes1, and this effect was effectively blocked by DBZ. Moreover, infusion of Ang II markedly increased the incidence and severity of AAA in Apo E−/− mice. In contrast, inhibition of Notch activation by DBZ prevented AAA formation in vivo. Furthermore, DBZ markedly prevented Ang II-stimulated accumulation of macrophages and CD4+ T cells, and ERK-mediated angiogenesis, simultaneously reversed Th2 response, in vivo. In conclusion, these findings provide new insight into the multiple mechanisms of Notch signaling involved in AAA formation and suggest that γ-secretase inhibitor DBZ might be a novel therapeutic drug for treating AAAS.

Dissecting Aneurysm in A Patient with Autosomal Dominant Polycystic Kidney Disease

Autosomal dominant polycystic kidney disease (ADPKD) is primarily associated with renal failure, but it also causes systemic diseases, including cysts of other systemic organs and cerebral or visceral aneurysm. To make matters worse, life-threatening aortic diseases are associated with ADPKD in some cases. However, only a few reports of ADPKD-associated with thoracic aortic dissection have been published. Herein, we present a case of dissecting aneurysm in a patient with hypertension and ADPKD. He had been followed up for type B aortic dissection for six years. Preoperative creatinine level ranged from 2.1 to 2.4 mg/dl. We performed replacement of the thoracic aorta with prosthetic graft successfully, and postoperatively, dialysis was not required.It is very important for us to recognize the relationship between ADPKD and thoracic aortic dissection, which can cause high mortality and morbidity rates.

Aortic disease associated with pregnancy

Our experience with the management of two patients with life-threatening aortic disease during pregnancy is presented with a review of the literature. One of our patients had intimal disruption caused by trauma; the other had probable Ehlers-Danlos type IV syndrome, causing an acute dissection of the descending thoracic aorta and eventually requiring replacement of the aorta from the left subclavian artery to common iliac arteries. The challenge of treating both the pregnant woman and the fetus was managed successfully by an emergent cesarean section followed by Dacron graft replacement of the descending thoracic aorta. The literature reviewed disclosed that aneurysm expansion producing symptoms and dissection is most common during the third trimester and during labor and delivery in patients with or without Marfan's syndrome. Half of the aortic dissections in women less than 40 years of age occur in association with pregnancy. The available evidence indicates that patients with known valvular or aortic disease should have surgical repairs during the first or second trimester and thereafter have delivery by cesarean section. However, patients with acute aortic problems near term appear to be better managed by cesarean section followed promptly by treatment of the aortic disease.