13 research outputs found
Treatment of Inguinal Lymph Node Metastases in Patients with Rectal Adenocarcinoma
Background
Inguinal lymph node metastases (ILNM) from rectal adenocarcinoma are rare and staged as systemic disease. This study aimed to provide insight into the treatment and prognosis of ILNM from rectal adenocarcinoma.
Methods
All patients with a diagnosis of synchronous or metachronous ILNM from rectal adenocarcinoma between January 2005 and March 2017 were retrospectively reviewed.
Result
Advancements in the Endovascular Management of Thoracic Aortic Pathologies
Over recent years, an improved consensus has been established regarding diagnosis and management of type B aortic dissection (TBAD). Primary conservative medical treatment with antihypertensive agents in combination with close surveillance seems to be justified in TBAD, until complications such as aneurysmal expansion, rupture, or progression of the initial dissection occur. Several clinical and radiological predictors of aortic growth in uncomplicated TBAD patients have been identified and can be used to select patients at high-risk for aortic enlargement and rupture during follow-up. Those patients might benefit from closer surveillance or early endovascular intervention.
Over recent decades, the management of thoracic aortic pathologies has evolved to include endovascular approaches next to conventional open aortic repair. Currently, thoracic endovascular aortic repair (TEVAR) is the preferred approach for patients presenting with complicated TBAD and other thoracic aortic pathologies. Advances in medical care have increased the number of patients surviving the acute phase of TBAD, forming a larger cohort presenting with chronic TBAD. A comparative analysis of open and endovascular approaches for chronic TBAD was performed. Large maximum aortic diameter (OR 1.1, p=0.001) and visceral aorta intervention (OR 3.5, p=0.026) independently predicted adverse early outcomes. Important predictors of late mortality included peripheral vascular disease (HR 2.5, p=0.021) and baseline creatinine (HR 1.7, p<0.001), but not treatment strategy (p=0.225). Conventional open aortic repair was associated with higher treatment efficacy, and TEVAR was an independent predictor of treatment failure (p=0.046), which warrants modification of current device design or endovascular approach before broad application of TEVAR for chronic TBAD.
To study patients treated with TEVAR in depth, computational fluid dynamics (CFD) can give important information about aortic hemodynamics, and helps to understand patient-specific changes in aortic geometry after TEVAR. Based on the analysis of pulsatile aortic changes, defined as aortic radial expansion and elongation during the cardiac cycle, increased changes after TEVAR along the different aortic segments were observed. Overall, dynamic imaging modalities help improve the evaluation of pulsatile aortic changes, specifically pre-TEVAR for stent graft sizing, and post-TEVAR to detect potential complications during follow-up. A patient-specific approach should be adopted in which stent graft design is focused on individual anatomy and morphologic changes. The expanding bioengineer-medical collaboration and increasing experience with dynamic aortic evaluation is therefore encouraging.
Additionally, endovascular aortic repair is continuously evolving. When TEVAR candidates have unfavorable iliac artery anatomy (small, tortuous, or calcified vessels), traditionally retroperitoneal iliac artery conduits have been considered as most appropriate route for stent graft delivery. More recently, the endoconduit approach has been introduced as alternative and can be performed using a standard femoral approach, avoiding the complications associated with a retroperitoneal approach.
Currently, TEVAR is also used to treat rare thoracic aortic pathologies, such as aberrant subclavian arteries with associated Kommerell diverticulum. The evolution towards endovascular and hybrid approaches to treat this aortic anomaly did not appear to affect late outcomes, suggesting that choice of treatment should be based on patient-specific anatomy and associated comorbidities
Update in the management of aortic dissection
Opinion statement: Recent improvements in diagnosis, peri-operative management, surgical techniques and postoperative care have resulted in decreased mortality and morbidity in acute aortic dissections (AAD). The classic treatment algorithm indicates that type A patients require direct surgical intervention and type B patients should be treated medically, in absence of complications. Initial medical treatment is adopted in all AAD patients, as it reduces propagation of the dissection and aortic rupture. In type A aortic dissection (TAAD) several techniques have contributed to major changes in the surgical approach, such as cerebral protection using moderate circulatory arrest, selective cerebral perfusion, and aortic valve sparing with root replacement. In TAAD with involvement of the descending aorta, thoracic endovascular aortic repair (TEVAR) can be performed as a part of a complex hybrid procedure, in which surgical ascending/arch repair is combined with the placement of a stent graft in the descending aorta. Future developments in stent graft technologies might broaden the usefulness of TEVAR for the total endovascular repair of TAAD. In complicated type B aortic dissection (TBAD), the use of TEVAR has become the therapy of first choice. By covering the proximal entry tear, the stent graft reduces the pressurization of the false lumen, treating malperfusion and inducing favorable aortic remodeling. In uncomplicated TBAD, TEVAR has been used to prevent long term complications, such as aortic aneurysm, but this concept is not yet routinely recommended. Regardless of their initial treatment, all AAD patients should be administered with strict antihypertensive management combined with imaging surveillance and careful periodic clinical follow-up
A compliant aortic model for in vitro simulations : design and manufacturing process
We design and manufacture a silicone model of the human aorta, able to mimic both the geometrical and the mechanical properties of physiological individuals, with a specific focus on reproducing the compliance. In fact, while the models available in the literature exhibit an unrealistic compliant behavior, though they are detailed from the geometrical viewpoint, here the goal is to provide an accurate compliant tool for in vitro testing the devices that interface with the vascular system. A parametric design of the aortic model is obtained based on the available literature data, and the model is manufactured with a specific silicone mixture using rapid prototyping and molding techniques. The manufactured prototype has been tested by means of computed tomography scans for evaluating the matching of the mechanical properties with the desired ones. Results show a high degree of adherence between the imposed and the measured compliance values for each main aortic section. Thus, our work proves the feasibility of the approach, and the possibility to manufacture compliant models that reproduce the mechanical behavior of the aorta for in vitro studies
Importance of dynamic aortic evaluation in planning TEVAR
Dynamic aortic evaluation in planning thoracic endovascular aortic repair (TEVAR) is important to provide optimal stent graft sizing. Static imaging protocols do not consider normal aortic dynamics and may lead to stent graft to aorta mismatch, causing stent graft related complications, such as type I endoleak and stent graft migration. Dynamic imaging can assist in accurate stent graft selection and sizing preoperatively, and evaluate stent graft performance during follow-up. To create new imaging technologies, integration of knowledge between diverse scientific fields is essential (i.e., engineering, informatics and medicine). Different dynamic imaging modalities, such as electrocardiographic-gated computed tomography angiography (ECG-gated CTA) and four-dimensional phase-contrast MRI (4D PC-MRI), are progressively investigated and implemented into clinical practice as important instruments in preoperative planning for TEVAR. In time, further application of dynamic imaging tools for preoperative screening and follow-up after TEVAR might lead to better outcomes for patients. The advances in dynamic imaging for evaluation of the thoracic aorta using new imaging modalities and their future perspectives are addressed in this manuscript
Impact of Thoracic Endovascular Aortic Repair on Pulsatile Circumferential and Longitudinal Strain in Patients With Aneurysm
Purpose: To quantify both pulsatile longitudinal and circumferential aortic strains before and after thoracic endovascular aortic repair (TEVAR), potentially clarifying TEVAR-related complications. Methods: This retrospective study assessed the impact of TEVAR on pulsatile aortic strains through custom developed software and cardiac-gated computed tomography imaging of 8 thoracic aneurysm patients (mean age 71.0 +/- 8.2 years; 6 men) performed before TEVAR and during follow-up (median 0.1 months, interquartile range 0.1-5.8). Lengths of the ascending aorta, the aortic arch, and the descending aorta were measured. Diameters and areas were computed at the sinotubular junction, brachiocephalic trunk, left subclavian artery, and the celiac trunk. Pulsatile longitudinal and circumferential strains were quantified as systolic increments of length and circumference divided by the corresponding diastolic values. Results: Average pulsatile longitudinal strain ranged from 1.4% to 7.1%, was highest in the arch (p< 0.001), and increased after TEVAR by 77% in the arch (7.1%+/- 2.5% vs 12.5%+/- 5.1%, p=0.04) and by 69% in the ascending aorta (5.6 +/- 2.3% vs 9.4 +/- 4.4%, p=0.06). Average pulsatile circumferential strain ranged from 3.6% to 5.0% before TEVAR and did not differ significantly throughout the thoracic aorta; there was a nonsignificant increase after TEVAR at the unstented sinotubular junction (5.0%+/- 1.4% vs 6.3%+/- 1.0%, p=0.18), with a significant increase at the celiac trunk (3.6%+/- 1.8% vs 6.2%+/- 1.8%, p=0.02). Pulsatile circumferential strains within stented segments were deemed unreliable due to image artifacts. Conclusion: TEVAR was associated with an increase of pulsatile longitudinal strains (in the arch) and circumferential strains (at the celiac trunk) in unstented aortic segments. These observations suggest increased pulsatile wall stress after TEVAR in segments adjacent to the device, which may contribute to the understanding of stent-graft-related complications such as retrograde dissection, aneurysm formation, and rupture
Predictors of aortic growth in uncomplicated type B aortic dissection
Background Patients with uncomplicated acute type B aortic dissection (ABAD) generally can be treated with conservative medical management. However, these patients may develop aortic enlargement during follow-up, with the risk for rupture, which necessitates intervention. Several predictors have been studied in recent years to identify ABAD patients at high risk for aortic enlargement who may benefit from early surgical or endovascular intervention. This study systematically reviewed and summarized the current available literature on prognostic variables related to aortic enlargement during follow-up in uncomplicated ABAD patients. Methods Studies were included if they reported predictors of aortic growth in uncomplicated ABAD patients. Studies about type A aortic dissection, aortic aneurysm, intramural hematoma, or ABAD that required acute intervention were excluded. Results A total of 18 full-text articles were selected. The following predictors of aortic growth in ABAD patients were identified: age <60 years, white race, Marfan syndrome, high fibrinogen-fibrin degradation product level ( 6520 \u3bcg/mL) at admission, aortic diameter 6540 mm on initial imaging, proximal descending thoracic aorta false lumen (FL) diameter 6522 mm, elliptic formation of the true lumen, patent FL, partially thrombosed FL, saccular formation of the FL, presence of one entry tear, large entry tear ( 6510 mm) located in the proximal part of the dissection, FL located at the inner aortic curvature, fusiform dilated proximal descending aorta, and areas with ulcer-like projections. Tight heart rate control (<60 beats/min), use of calcium-channel blockers, thrombosed FL, two or more entry tears, FL located at the outer aortic curvature, and circular configuration of the true lumen were associated with negative or limited aortic growth. Conclusions Several predictors might be used to identify those ABAD patients at high risk for aortic growth. Although conservative management remains indicated in uncomplicated ABAD, these patients might benefit from closer follow-up or early endovascular intervention
Predicting aortic enlargement in type B aortic dissection
Patients with uncomplicated acute type B aortic dissection (ABAD) can generally be treated with conservative medical management. However, these patients may develop aortic enlargement during follow-up, with the risk of rupture. Several predictors have been studied in recent years to identify ABAD patients at high risk of aortic enlargement, who may benefit from early surgical or endovascular intervention. This study reviewed and summarized the current available literature on prognostic variables related to aortic enlargement during follow-up in uncomplicated ABAD patients. It revealed multiple factors affecting aortic expansion including demographic, clinical, pharmacologic and radiologic variables. Such predictors may be used to identify those ABAD patients at higher risk for aortic enlargement who may benefit from closer radiologic surveillance or early endovascular intervention. This approach deserves even more consideration because a significant number of patients develop aneurysmal degeneration along the dissected segments during follow-up, and may lose the opportunity for endovascular treatment if not identified at an early stage
Biomarkers in TAA—The Holy Grail
Thoracic aortic aneurysm (TAA) is a silent disease, often discovered at a time point that dramatic complications, as rupture and dissection, occur. For the detection of asymptomatic TAA and prevention of such complications, it is essential to have an adequate screening tool. Until now, routine laboratory blood tests have played only a minor role in the screening, diagnosis, tracking and prediction of the natural history of TAAs. However, the knowledge about biomarkers is rapidly expanding in the cardiovascular field, and there are several potential biomarkers that might be implemented into TAA clinical practice in the near future. The most important and promising markers for TAA will be discussed in this overview