Cyber medicine enables remote neuromonitoring during aortic surgery

This study assessed the feasibility and effectiveness of remote neuromonitoring as an adjunct to spinal cord protection during surgical repair of descending thoracic aortic aneurysms and thoracoabdominal aortic aneurysms.

Severe structural damage of the seemingly non-diseased infrarenal aortic aneurysm neck

OBJECTIVE: The success of open and endovascular repair of abdominal aortic aneurysms (AAA) is hampered by postoperative dilatation of the anatomical neck of the AAA, which is used for graft attachment. The purpose of this study was to determine whether the macroscopically non-diseased infrarenal aortic neck of AAA is histologically and biochemically altered at the time of operative repair. METHODS: We harvested full-thickness aortic wall samples as longitudinal stripes spanning from AAA neck to aneurysmal sac in 22 consecutive patients undergoing open surgical AAA repair. Control tissue was obtained from five organ donors and five deceased subjects undergoing autopsy without evidence of aneurysmal disease. We assessed aortic media thickness, number of intact elastic lamellar units, media destruction, and neovascularization grade and performed immunohistochemistry for matrix metalloproteinase (MMP)-9 and phosphorylated c-Jun N-terminal kinase (p-JNK). MMP-9 and p-JNK protein expressions were quantified using Western Blots. RESULTS: The median thickness of the aortic media was 1150 mum in control tissue (range, 1000-1300), 510 mum in aortic necks (250-900), and 200 mum in aortic sacs (50-500, P from nonparametric test for trend <.001). The number of intact elastic lamellar units was 33 in controls (range, 33-55), 12 in aortic necks (0-31) and three in aortic sacs (0-10, P < .001). The expression of MMP-9 and p-JNK as assessed by Western Blots (P = .007 and .061, respectively) and zymography (P for trend <.001) were up regulated in both the AAA neck and sac compared with controls. Except for p-JNK expression, differences between tissues were similar after the adjustment for age, gender, and type of sampling. CONCLUSION: The seemingly non-diseased infrarenal AAA neck in patients with AAA undergoing surgical repair shows histological signs of destruction and upregulation of potential drug targets.

Technical advances improved outcome in patients undergoing surgery of the ascending aorta and/or aortic arch: ten years experience

BACKGROUND: Several technical advances in thoracic aortic surgery, such as the use of antegrade cerebral perfusion, avoidance of cross-clamping and the application of glue, have beneficially influenced postoperative outcome. The aim of the present study was to analyse the impact of these developments on outcome of patients undergoing surgery of the thoracic aorta. METHODS AND RESULTS: Between January 1996 and December 2005, 835 patients (37.6%) out of 2215 aortic patients underwent surgery on the thoracic ascending aorta or the aortic arch at our institution. All in-hospital data were assessed. Two hundred and forty-one patients (28.8%) suffered from acute type A dissection (AADA). Overall aortic caseload increased from 41 patients in 1996 to 141 in 2005 (+339%). The increase was more pronounced for thoracic aortic aneurysms (TAA) (+367.9%), than for acute type A aortic dissections (+276.9%). Especially in TAA, combined procedures increased and the amount of patients with impaired left ventricular function (EF <50%) raised up from 14% in 1996 to 24% in 2005. Average age remained stable. Logistic regression curve revealed a significant decrease in mortality (AADA) and in the overall incidence of neurological deficits. CONCLUSIONS: Technical advances in the field of thoracic aortic surgery lead to a decrease of mortality and morbidity, especially in the incidence of adverse neurological events, in a large collective of patients. Long-term outcome and quality of life are better, since antegrade cerebral perfusion has been introduced.

Arterial access through the right subclavian artery in surgery of the aortic arch improves neurologic outcome and mid-term quality of life

BACKGROUND: We have shown that selective antegrade cerebral perfusion improves mid-term quality of life in patients undergoing surgical repair for acute type A aortic dissection and aortic aneurysms. The aim of the study was to assess the impact of continuous cerebral perfusion through the right subclavian artery on immediate outcome and quality of life. METHODS: Perioperative data of 567 consecutive patients who underwent surgery of the aortic arch using deep hypothermic circulatory arrest have been analyzed. Patients were divided into three groups, according to the management of cerebral protection. Three hundred eighty-seven patients (68.3%) had deep hypothermic circulatory arrest with pharmacologic protection with pentothal only, 91 (16.0%) had selective antegrade cerebral perfusion and pentothal, and 89 (15.7%) had continuous cerebral perfusion through the right subclavian artery and pentothal. All in-hospital data were assessed, and quality of life was analyzed prospectively 2.4 +/- 1.2 years after surgery with the Short Form-36 Health Survey Questionnaire. RESULTS: Major perioperative cerebrovascular injuries were observed in 1.1% of the patients with continuous cerebral perfusion through the right subclavian artery, compared with 9.8% with selective antegrade cerebral perfusion (p < 0.001) and 6.5% in the group with no antegrade cerebral perfusion (p = 0.007). Average quality of life after an arrest time between 30 and 50 minutes with continuous cerebral perfusion through the right subclavian artery was significantly better than selective antegrade cerebral perfusion (90.2 +/- 12.1 versus 74.4 +/- 40.7; p = 0.015). CONCLUSIONS: Continuous cerebral perfusion through the right subclavian artery improves considerably perioperative brain protection during deep hypothermic circulatory arrest. Irreversible perioperative neurologic complications can be significantly reduced and duration of deep hypothermic circulatory arrest can be extended up to 50 minutes without impairment in quality of life.

[Abdominal aortic aneurysm]

Abdominal aortic aneurysms (AAA) confer a substantial healthcare burden in the Western world. Surgical or endovascular therapy is indicated in patients with a maximum diameter exceeding 5.5 cm. Patients with smaller AAA must undergo a specific ultrasound surveillance program aimed at avoiding exposure to an increased risk of rupture once their AAA exceeds the threshold for active treatment. Based on improved understanding of the pathophysiology of AAA, recent years provided initial insight into potential medical treatment options. The presence of AAA is currently regarded a coronary artery disease risk equivalent. ACE inhibitors, statins and JNK-inhibitors were shown to have the potential to slow down progression. Since cigarette smoking is the main risk factor for both the development and progression of AAA, smoking cessation remains a key goal. Further prospective studies will assess the clinical efficacy of various promising drug treatment approaches aimed at slowing disease progression of small AAA and after endovascular therapy.

State-of-the-art aortic imaging: Part II - applications in transcatheter aortic valve replacement and endovascular aortic aneurysm repair.

Transcatheter aortic valve replacement (TAVR) as well as thoracic and abdominal endovascular aortic repair (TEVAR and EVAR) rely on accurate pre- and postprocedural imaging. This review article discusses the application of imaging, including preprocedural assessment and measurements as well as postprocedural imaging of complications. Furthermore, the exciting perspective of computational fluid dynamics (CFD) based on cross-sectional imaging is presented. TAVR is a minimally invasive alternative for treatment of aortic valve stenosis in patients with high age and multiple comorbidities who cannot undergo traditional open surgical repair. Given the lack of direct visualization during the procedure, pre- and peri-procedural imaging forms an essential part of the intervention. Computed tomography angiography (CTA) is the imaging modality of choice for preprocedural planning. Routine postprocedural follow-up is performed by echocardiography to confirm treatment success and detect complications. EVAR and TEVAR are minimally invasive alternatives to open surgical repair of aortic pathologies. CTA constitutes the preferred imaging modality for both preoperative planning and postoperative follow-up including detection of endoleaks. Magnetic resonance imaging is an excellent alternative to CT for postoperative follow-up, and is especially beneficial for younger patients given the lack of radiation. Ultrasound is applied in screening and postoperative follow-up of abdominal aortic aneurysms, but cross-sectional imaging is required once abnormalities are detected. Contrast-enhanced ultrasound may be as sensitive as CTA in detecting endoleaks.

Dissecting abdominal aortic aneurysm in Ang II-infused mice: suprarenal branch ruptures and apparent luminal dilatation.

AIMS In this work, we provide novel insight into the morphology of dissecting abdominal aortic aneurysms in angiotensin II-infused mice. We demonstrate why they exhibit a large variation in shape and, unlike their human counterparts, are located suprarenally rather than infrarenally. METHODS AND RESULTS We combined synchrotron-based, ultra-high resolution ex vivo imaging (phase contrast X-Ray tomographic microscopy) with in vivo imaging (high-frequency ultrasound and contrast-enhanced micro-CT) and image-guided histology. In all mice, we observed a tear in the tunica media of the abdominal aorta near the ostium of the celiac artery. Independently we found that, unlike the gradual luminal expansion typical for human aneurysms, the outer diameter increase of angiotensin II-induced dissecting aneurysms in mice was related to one or several intramural haematomas. These were caused by ruptures of the tunica media near the ostium of small suprarenal side branches, which had never been detected by the established small animal imaging techniques. The tear near the celiac artery led to apparent luminal dilatation, while the intramural haematoma led to a dissection of the tunica adventitia on the left suprarenal side of the aorta. The number of ruptured branches was higher in those aneurysms that extended into the thoracic aorta, which explained the observed variability in aneurysm shape. CONCLUSION Our results are the first to describe apparent luminal dilatation, suprarenal branch ruptures, and intramural haematoma formation in dissecting abdominal aortic aneurysms in mice. Moreover, we validate and demonstrate the vast potential of phase contrast X-ray tomographic microscopy in cardiovascular small animal applications.

Identification and in silico analyses of novel TGFBR1 and TGFBR2 mutations in Marfan syndrome-related disorders

Very recently, heterozygous mutations in the genes encoding transforming growth factor beta receptors I (TGFBR1) and II (TGFBR2) have been reported in Loeys-Dietz aortic aneurysm syndrome (LDS). In addition, dominant TGFBR2 mutations have been identified in Marfan syndrome type 2 (MFS2) and familial thoracic aortic aneurysms and dissections (TAAD). In the past, mutations of these genes were associated with atherosclerosis and several human cancers. Here, we report a total of nine novel and one known heterozygous sequence variants in the TGFBR1 and TGFBR2 genes in nine of 70 unrelated individuals with MFS-like phenotypes who previously tested negative for mutations in the gene encoding the extracellular matrix protein fibrillin-1 (FBN1). To assess the pathogenic impact of these sequence variants, in silico analyses were performed by the PolyPhen, SIFT, and Fold-X algorithms and by means of a 3D homology model of the TGFBR2 kinase domain. Our results showed that in all but one of the patients the pathogenic effect of at least one sequence variant is highly probable (c.722C > T, c.799A > C, and c.1460G > A in TGFBR1 and c.773T > G, c.1106G > T, c.1159G > A, c.1181G > A, and c.1561T > C in TGFBR2). These deleterious alleles occurred de novo or segregated with the disease in the families, indicating a causative association between the sequence variants and clinical phenotypes. Since TGFBR2 mutations found in patients with MFS-related disorders cannot be distinguished from heterozygous TGFBR2 mutations reported in tumor samples, we emphasize the importance of segregation analysis in affected families. In order to be able to find the mutation that is indeed responsible for a MFS-related phenotype, we also propose that genetic testing for sequence alterations in TGFBR1 and TGFBR2 should be complemented by mutation screening of the FBN1 gene.

The frozen elephant trunk: an interesting hybrid endovascular-surgical technique to treat complex pathologies of the thoracic aorta

The treatment of complex aortic pathologies involving the ascending aorta, the aortic arch, and the descending aorta remains a challenging issue in aortic surgery. The frozen elephant trunk procedure effectively combines surgical and interventional technologies in the treatment of extensive aortic aneurysms and dissections. We present two patients with complex aortic lesions involving all three segments of the thoracic aorta. The device used in our series is the new E-vita open hybrid prosthesis consisting of a proximal woven polyester tube and a distal self-expandable nitinol stent graft, which can be delivered antegrade into the descending aorta.

Three-dimensional imaging core laboratory of the endovascular aneurysm repair trials: validation of methodology

OBJECTIVE: The aim of this study was to establish and validate a three-dimensional imaging protocol for the assessment of Computed Tomography (CT) scans of abdominal aortic aneurysms in UK EVAR trials patients. Quality control and repeatability of anatomical measurements is important for the validity of any core laboratory. METHODS: Three different observers performed anatomical measurements on 50 preoperative CT scans of aortic aneurysms using the Vitrea 2 three-dimensional post-imaging software in a core laboratory setting. We assessed the accuracy of intra and inter observer repeatability of measurements, the time required for collection of measurements, 3 different levels of automation and 3 different automated criteria for measurement of neck length. RESULTS: None of the automated neck length measurements demonstrated sufficient accuracy and it was necessary to perform checking of the important automated landmarks. Good intra and limited inter observer agreement were achieved with three-dimensional assessment. Complete assessment of the aneurysm and iliacs took an average (SD) of 17.2 (4.1) minutes. CONCLUSIONS: Aortic aneurysm anatomy can be assessed reliably and quickly using three-dimensional assessment but for scans of limited quality, manual checking of important landmarks remains necessary. Using a set protocol, agreement between observers is satisfactory but not as good as within observers.

Intrapulmonale Ruptur eines Aortenaneurysmas

Aneurysmen der thorakalen Aorta führen in der Regel über eine intraperikardiale (Herzbeuteltamponade) oder intrapleurale Ruptur (inneres Verbluten) zum Tod. Außerordentlich selten sind intrapulmonale Rupturen von thorakalen Aortenaneurysmen, die über eine Hämoptyse symptomatisch werden und über eine Blutaspiration letal verlaufen können. Berichtet wird über den Fall eines 40-jährigen Mannes, bei dem nach thorakalen Schmerzen an den Vortagen plötzlich eine Hämoptyse auftrat. Während der diagnostischen Abklärung der Blutungsquelle verstarb er unvorhergesehen. Todesursache war die primäre intrapulmonale, final intrapleurale Ruptur eines thorakalen Aortenaneurysmas an der Stelle einer operativ korrigierten Aortenisthmusstenose.

Long-term results of thoracic endovascular aortic repair in atherosclerotic aneurysms involving the descending aorta

This study evaluated long-term results of thoracic endovascular aortic repair for atherosclerotic aneurysms involving descending aorta.

Midterm results of thoracic endovascular aortic repair in patients with aneurysms involving the descending aorta originating from chronic type B dissections

Midterm results of TEVAR (thoracic endovascular aortic repair) in patients with aneurysms involving the descending aorta originating from chronic type B dissections are not known.

[Ascending aortic and pulmonary trunk aneurysms]

A case of two non-atherosclerotic aneurysms localised in the ascending aorta and in the pulmonary trunk is presented. Histopathologically, a severe granulomatous inflammation affecting the whole aneurysms wall was documented. To the best of our knowledge it is the second ever documented case of simultaneous occurrence of aneurysms in the aorta and the pulmonary artery.