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OBJECTIVE: Clinical guidelines provide recommendations on the minimal blood vessel diameters required for arteriovenous fistula creation but the evidence for these recommendations is limited. We compared vascular access outcomes of fistulas created in agreement with the ESVS Clinical Practice Guidelines (i.e. arteries and veins >2 mm for forearm fistulas and >3 mm for upper arm fistulas) with fistulas created outside these recommendations. METHODS: The multicenter Shunt Simulation Study cohort contains 211 hemodialysis patients who received a first radiocephalic, brachiocephalic, or brachiobasilic fistula before publication of the ESVS Clinical Practice Guidelines. All patients had preoperative duplex ultrasound measurements according to a standardized protocol. Outcomes included duplex ultrasound findings at 6 weeks after surgery, vascular access function, and intervention rates until 1 year after surgery. RESULTS: In 55% of patients, fistulas were created in agreement with the ESVS Clinical Practice Guidelines recommendations on minimal blood vessel diameters. Concordance with the guideline recommendations was more frequent for forearm fistulas than for upper arm fistulas (65% vs 46%, p = 0.01). In the entire cohort, agreement with the guideline recommendations was not associated with an increased proportion of functional vascular accesses (70% vs 66% for fistulas created within and outside guideline recommendations, respectively; p = 0.61) or with decreased access-related intervention rates (1.45 vs 1.68 per patient-year, p = 0.20). In forearm fistulas, however, only 52% of arteriovenous fistulas created outside these recommendations developed into a timely functional vascular access. CONCLUSIONS: Whereas upper arm arteriovenous fistulas with preoperative blood vessel diameters <3 mm had similar vascular access function as fistulas created with larger blood vessels, forearm arteriovenous fistulas with preoperative blood vessel diameters <2 mm had poor clinical outcomes. These results support that clinical decision-making should be guided by an individual approach.

RESUMEN

OBJECTIVE: Although observational cohort studies report that interventions to achieve functionality are clinically successful in 85% of patients, the proportion of newly created autologous arteriovenous fistulas that result in functional vascular access typically is only 70 - 80%. To address this discrepancy, the selection and outcomes of interventions to achieve functionality in a multicentre prospective cohort study were analysed. METHODS: The Shunt Simulation Study enrolled 222 patients who needed a first arteriovenous fistula in nine dialysis units in The Netherlands from 2015 to 2018 and followed these patients until one year after access creation. In this observational study, the technical and clinical success rates of interventions to achieve functionality based on lesion and intervention characteristics were analysed and the clinical outcomes of arteriovenous fistulas with assisted and unassisted functionality were compared. RESULTS: For patients who were on dialysis treatment at the end of the study, unassisted fistula functionality was 54% and overall fistula functionality was 78%. Thirty-four per cent of arteriovenous fistulas required an intervention to achieve functionality, 68% of which eventually became functional. Seventy-five per cent of these interventions were percutaneous balloon angioplasties of vascular access stenoses. Patients with clinically successful interventions to achieve functionality had larger pre-operative vein diameters (2.8 ± 1.0 mm vs. 2.3 ± 0.6 mm, p = .036) and less often presented with thrombosed fistulas than patients with unsuccessful interventions (7% vs. 43%, p = .006). Arteriovenous fistulas with assisted functionality had similar secondary patency as fistulas with unassisted functionality (100% and 98% at six months, p = .44), although they required more interventions to maintain function (2.6 vs. 1.7 per year; rate ratio 1.52, 95% CI 1.04 - 2.18, p = .032). CONCLUSION: Interventions to achieve functionality were needed in about a third of newly created arteriovenous fistulas. Most thrombosed fistulas were abandoned, and when selected for thrombectomy rarely reached clinical success. On the other hand, interventions to achieve functionality of patent fistulas had high clinical success rates and therefore can be done repeatedly until the fistula has become functional.

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Perylene bisimides (PBIs) have received great attention in their applicability to optoelectronics. Especially, symmetry-breaking charge separation (SB-CS) in PBIs has been investigated to mimic the efficient light capturing and charge generation in natural light-harvesting systems. However, unlike ultrafast CS dynamics in donor-acceptor heterojunction materials, ultrafast SB-CS in a stacked homodimer has still been challenging due to excimer formation in the absence of rigidifying surroundings such as a special pair in the natural systems. Herein, we present the detailed mechanism of ultrafast photoinduced SB-CS occurring in a 1,7-bis(N-pyrrolidinyl) PBI dimer within a cyclophane. Through narrow-band and broad-band transient absorption spectroscopy, we demonstrate that ultrafast SB-CS in the dimer is enabled by the combination of (1) vibrationally coherent charge-transfer resonance-enhanced excimer formation and (2) breakdown of adiabaticity (formation of SB-CS diabats) in the excimer state via structural and solvent fluctuation. Quantum chemical calculations also underpin that the participation of strong electron-donating substituents in overall vibrational modes plays a crucial role in triggering the ultrafast SB-CS. Therefore, our work provides an alternative route to facilitate ultrafast SB-CS in PBIs and thereby establishes a novel strategy for the design of optoelectronic materials.

RESUMEN

OBJECTIVE: An arteriovenous fistula (AVF) needs to mature before it becomes suitable to cannulate for haemodialysis treatment. Maturation importantly depends on the post-operative flow increase. Unfortunately, 20-40% of AVFs fail to mature (FTM). A patient specific computational model that predicts immediate post-operative flow was developed, and it was hypothesised that providing information from this model for planning of fistula creation might reduce FTM rates. METHODS: A multicentre, randomised controlled trial in nine Dutch hospitals was conducted in which patients with renal failure who were referred for AVF creation, were recruited. Patients were randomly assigned (1:1) to the control or computer simulation group. Both groups underwent a work up, with physical and duplex ultrasonography (DUS) examination. In the simulation group the data from the DUS examination were used for model simulations, and based on the immediate post-operative flow prediction, the ideal AVF configuration was recommended. The primary endpoint was AVF maturation defined as an AVF flow ≥500 mL/min and a vein inner diameter of ≥4 mm six weeks post-operatively. The secondary endpoint was model performance (i.e. comparisons between measured and predicted flows, and (multivariable) regression analysis for maturation probability with accompanying area under the receiver operator characteristic curve [AUC]). RESULTS: A total of 236 patients were randomly assigned (116 in the control and 120 in the simulation group), of whom 205 (100 and 105 respectively) were analysed for the primary endpoint. There was no difference in FTM rates between the groups (29% and 32% respectively). Immediate post-operative flow prediction had an OR of 1.15 (1.06-1.26; p < .001) per 100 mL/min for maturation, and the accompanying AUC was 0.67 (0.59-0.75). CONCLUSION: Providing pre-operative patient specific flow simulations during surgical planning does not result in improved maturation rates. Further study is needed to improve the predictive power of these simulations in order to render the computational model an adjunct to surgical planning.

Asunto(s)

Fístula Arteriovenosa/cirugía , Diálisis Renal/métodos , Remodelación Vascular , Anciano , Circulación Sanguínea , Femenino , Humanos , Masculino , Persona de Mediana Edad

RESUMEN

Excimer, a configurational mixing between Frenkel exciton and charge-transfer resonance states, is typically regarded as a trap state that hinders desired energy or charge-transfer processes in artificial molecular assemblies. However, in recent days, the excimer has received much attention as a functional intermediate in the excited-state dynamics such as singlet fission or charge-separation processes. In this work, we show that the relative contribution to charge-transfer resonance of the excimer state in a bay-substituted perylene bisimide dimer cyclophane can be modulated by dielectric properties of the solvents employed. Solvent-dependent time-resolved fluorescence and absorption measurements reveal that an enhancement of charge-transfer resonance in the excimer state is reflected by incomplete symmetry-breaking charge-separation processes from the structurally relaxed excimer state by means of dipolar solvation processes in the high dielectric environment.

RESUMEN

The optical properties of a series of three cyclophanes comprising either identical or different perylene bisimide (PBI) chromophores were studied by UV/Vis absorption spectroscopy and their distinctive spectral features were analyzed. All the investigated cyclophanes show significantly different absorption features with respect to the corresponding constituent PBI monomers indicating strong coupling interactions between the PBI units within the cyclophanes. DFT calculations suggest a π-stacked arrangement of the PBI units at close van der Waals distance in the cyclophanes with rotational displacement. Simulations of the absorption spectra based on time-dependent quantum mechanics properly reproduced the experimental spectra, revealing exciton-vibrational coupling between the chromophores both in homo- and heterodimer stacks. The PBI cyclophane comprising two different PBI chromophores represents the first example of a PBI heterodimer stack for which the exciton coupling has been investigated. The quantum dynamics analysis reveals that exciton coupling in heteroaggregates is indeed of similar strength as for homoaggregates.

RESUMEN

We have elucidated excimer-mediated intramolecular electron transfer in cofacially stacked PBIs tethered by two phenylene-butadiynylene loops. The electron transfer between energetically equivalent PBIs is revealed by the simultaneous observation of the PBI radical anion and cation bands in the transient absorption spectra. The fluorescence decay time of the excimer states is in good agreement with the rise time of PBI radical bands in transient absorption spectra suggesting that the electron transfer dynamics proceed via the excimer state. We can conclude that the excimer state effectuates the efficient charge transfer in the cofacially stacked PBI dimer.

RESUMEN

Complications of renal artery aneurysms (RAAs) can be life threatening and include the spontaneous rupture which may lead to severe retroperitoneal hemorrhage, loss of the kidney, or death. As the incidence and diagnosis of RAAs is expected to rise, it is becoming increasingly important to enhance our awareness and knowledge of this rare clinical entity. Here, we present the case of a hilar right RAA and the surgical approach for primary repair during the postpartum period. Additionally, we discuss current pathophysiologic mechanisms, associated symptoms as well as current treatment modalities for RAAs.

RESUMEN

OBJECTIVE: Interruption of the hypogastric artery by ligation, embolization, or coverage frequently results in ischemic complications. The aim of this study was to compare the rate and risk factors for the development of ischemic complications after interruption of the hypogastric artery in obstetrics and gynecology (OBG), vascular surgery, oncology, and trauma patients. METHODS: MEDLINE, Ovid, and Scopus were searched for articles containing data of patients who underwent interruption of the hypogastric artery. Based on the indication, details of the procedure, and complications developed, data were categorized and a systematic review was done to evaluate any significant differences. RESULTS: A total of 394 patients (median age, 48.5 years) from 124 papers were included in the study; 31% of the study population was male and 69% was female. Indication for interruption was OBG related in 53.3%, vascular surgery related in 25.1%, oncology related in 17.5%, and trauma related in 4.1% of patients. Overall ischemic complication rate was 22.6%, comprising buttock claudication in 12.2%, buttock necrosis in 4.8%, erectile dysfunction in 2.7%, spinal cord ischemia in 4.0%, colonic ischemia in 2.5%, and bladder necrosis in 0.8%. Complications were fewer in patients younger than the median age of 48.5 years (12.8%) compared with those older than the median age (36.3%; P < .01), women compared with men (13.1% vs 41.7%; P < .01), OBG patients compared with vascular surgery patients (9.5% vs 37.4%; P < .01), patients after ligation compared with embolization (9.4% vs 31.0%; P < .01), and proximal interruption compared with distal interruption (19.6% vs 51.4%; P < .01). No significant difference in complications was seen after bilateral interruption compared with unilateral interruption (20.6% vs 27.1%; P > .05). Similarly, no significant difference in complication rate was seen with the type of embolization material used. Among OBG patients, ligations resulted in fewer complications compared with embolization (4.1% vs 16.7%; P < .01). Among vascular surgery patients, bilateral embolization resulted in a higher rate of complications compared with bilateral ligation (83.3% vs 30.5%; P < .01). Among oncology patients, fewer complications were seen after proximal interruption compared with distal interruption (25.5% vs 75%; P = .01). No significant differences in outcome were seen with regard to gender, laterality, and material used for embolization when patients were compared within each specialty. CONCLUSIONS: Interruption of the hypogastric artery is relatively safe in young and OBG patients compared with vascular surgery and oncology patients. Ligation of the hypogastric arteries is preferred to embolization, and proximal embolization should be preferred to distal embolization to decrease the risk of ischemic complications. Randomized controlled trials with larger sample size are needed to definitively elucidate clear risk factors for development of complications after hypogastric artery interruption.

Asunto(s)

Implantación de Prótesis Vascular , Embolización Terapéutica , Arteria Ilíaca/cirugía , Pelvis/irrigación sanguínea , Adolescente , Adulto , Factores de Edad , Anciano , Implantación de Prótesis Vascular/efectos adversos , Distribución de Chi-Cuadrado , Embolización Terapéutica/efectos adversos , Femenino , Humanos , Arteria Ilíaca/fisiopatología , Isquemia/etiología , Isquemia/fisiopatología , Ligadura , Modelos Logísticos , Masculino , Persona de Mediana Edad , Oportunidad Relativa , Flujo Sanguíneo Regional , Medición de Riesgo , Factores de Riesgo , Resultado del Tratamiento , Adulto Joven

RESUMEN

OBJECTIVE: The Stenting with Angioplasty and Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial compared carotid endarterectomy (CEA) to carotid artery stenting (CAS) among high-risk patients using a model of risk that has not been validated by previous publications. The objective of our study was to determine the accuracy of this high-risk model and to determine the true risk factors that result in patients being at high risk for CEA. METHODS: Prospectively collected data for 3098 CEAs between 2003 and 2011 at 20 Vascular Surgery Group of New England (VSGNE) centers were used. SAPPHIRE general inclusion criteria and primary outcomes were assessed. Factors that were associated with the primary outcome by analysis of variance (P < .10) and not linearly dependent, as determined by a Pearson correlation analysis, were further assessed for an independent association by multivariate logistic regression. A risk index model was developed for these significant predictors to accurately define high-risk CEA. RESULTS: The average patient age was 69.9 ± 9.5 years, 60% were male, and 45.7% were asymptomatic. The 1-year composite outcome event rate, defined as postoperative myocardial infarction and stroke or death, was 14.2%. Multivariate analysis (P < .05) found the following independently significant risk factors: age in years (95% confidence interval [CI], 1.0-1.1; P < .001), preadmission living in a nursing home (95% CI, 1.2-6.6; P = .020), congestive heart failure (95% CI, 1.4-2.8; P < .001), diabetes mellitus (DM; 95% CI, 1.1-1.3; P < .001), chronic obstructive pulmonary disease (95% CI, 1.2-1.5; P < .001), any previous cerebrovascular disease (95% CI, 1.1-1.9; P = .003), and contralateral internal carotid artery stenosis (95% CI, 1.0-1.2; P = .001). Three of the SAPPHIRE high-risk criteria-abnormal stress test, recurrent stenosis after CEA, and previous radiotherapy to the neck-were not independently associated with an adverse outcome. Independently significant risk factors not included in the SAPPHIRE criteria are inclusion of ages <80 years, preadmission living in a nursing home, DM, contralateral carotid stenosis, and any previous cerebrovascular accident. The risk index predictors are age in years (40-49: 0 points; 50-59: 2 points; 60-69: 4 points; 70-79: 6 points; 80-89: 8 points), living in a nursing home (4 points), any cardiovascular disease (2 points), congestive heart failure (5 points), chronic obstructive pulmonary disease (3 points), DM (2 points), degree of contralateral stenosis (<50%: 0 points; 50%-69%: 1 point; 70%-near occlusion: 2 points; occlusion: 3 points). High-risk CEA is defined as >13 points, representing adverse outcome rate of 22.5%. CONCLUSIONS: SAPPHIRE and other previously reported high-risk CAS inclusion criteria do not include all of the factors found to be independently associated with outcomes. Further studies are required to determine whether CAS is inferior to CEA in high-risk patients using a validated model of risk. In addition, this preoperative assessment includes novel criteria that can be used to stratify risks.

Asunto(s)

Endarterectomía Carotidea/efectos adversos , Factores de Edad , Anciano , Estenosis Carotídea , Trastornos Cerebrovasculares/complicaciones , Complicaciones de la Diabetes , Femenino , Insuficiencia Cardíaca/complicaciones , Humanos , Modelos Logísticos , Masculino , Infarto del Miocardio/etiología , New England , Casas de Salud , Complicaciones Posoperatorias , Periodo Preoperatorio , Estudios Prospectivos , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Factores de Riesgo , Accidente Cerebrovascular/etiología , Resultado del Tratamiento

RESUMEN

Purpose : To assess the comparative effectiveness of thoracic endovascular aortic repair (TEVAR) vs. open surgical repair (OSR) of complicated acute type B aortic dissections (cABAD) using decision analysis. Methods : A decision analysis comparing TEVAR and OSR for cABAD included variables extracted from the best-available evidence. Main outcomes were quality-adjusted life years (QALYs), presented with the 95% credibility intervals (CI), and number of reinterventions over the remaining lifetime. Different clinical scenarios, including age, gender, and risk profile were analyzed. Parameter uncertainty was analyzed using probabilistic sensitivity analysis. Results : In the reference case, a cohort of 55-year-old men, TEVAR was preferred over OSR: 7.07 QALYs (95% CI 6.77 to 7.38) vs. 6.34 QALYs (95% CI 6.04 to 6.66) for OSR. The difference of 0.73 QALYs (95% CI 0.29 to 1.17) is equal to 8.5 months in perfect health. TEVAR was more effective in all analyzed cases and age groups. Perioperative mortality was the most important variable affecting the difference between OSR and TEVAR, followed by the relative risk and percentage of aortic-related complications. Total expected reinterventions were 0.43/patient (TEVAR) and 0.35/patient (OSR). Conclusion : The results of this decision model for the treatment of cABAD suggest that TEVAR is preferred over OSR. Although a higher number of reinterventions is expected, the total effectiveness of TEVAR is higher for all age groups. OSR should be reserved for patients whose aortic anatomy is unsuitable for endovascular repair.

Asunto(s)

Aneurisma de la Aorta Torácica/cirugía , Disección Aórtica/cirugía , Procedimientos Endovasculares , Procedimientos Quirúrgicos Vasculares , Enfermedad Aguda , Disección Aórtica/diagnóstico , Disección Aórtica/mortalidad , Aneurisma de la Aorta Torácica/diagnóstico , Aneurisma de la Aorta Torácica/mortalidad , Investigación sobre la Eficacia Comparativa , Simulación por Computador , Técnicas de Apoyo para la Decisión , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/mortalidad , Medicina Basada en la Evidencia , Humanos , Masculino , Cadenas de Markov , Persona de Mediana Edad , Selección de Paciente , Complicaciones Posoperatorias/mortalidad , Complicaciones Posoperatorias/cirugía , Años de Vida Ajustados por Calidad de Vida , Reoperación , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Procedimientos Quirúrgicos Vasculares/efectos adversos , Procedimientos Quirúrgicos Vasculares/mortalidad

RESUMEN

OBJECTIVE: Open revascularization (OR) has been the treatment of choice for chronic mesenteric ischemia (CMI) for many years, but endovascular revascularization (EV) has been increasingly used with good short-term results. In this study, we evaluated the comparative effectiveness and cost-effectiveness of EV and OR in patients with CMI refractory to conservative management. METHODS: A Markov-state transition model was developed using TreeAge Pro 2012 (TreeAge Inc, Williamstown, Mass) to simulate a hypothetical cohort of 10,000 65-year-old female patients with CMI requiring treatment with either OR or EV. Data for the model, including perioperative and long-term overall mortality risks, disease-specific mortality risks, complications, and reintervention and patency rates, were retrieved from original studies and systematic reviews about CMI. Costs were analyzed with the 2013 Medicare database. Outcomes evaluated were quality-adjusted life-years (QALYs), costs from the health care perspective, and the incremental cost-effectiveness ratio. Extensive sensitivity analyses were performed and different clinical scenarios evaluated. Probabilistic sensitivity analysis was performed to assess robustness of the model. RESULTS: For a reference-case 65-year-old female patient with CMI and an average risk for operation, EV is preferred with 10.03 QALYs (95% credibility interval [CI], 9.76-10.29) vs 9.59 after OR (95% CI, 9.29-9.87). The difference is comparable to 5 months in perfect health: 0.44 QALY (95% CI, 0.13-0.76). For 65-year-old men, this was 8.71 QALYs (95% CI, 8.48-8.94) for EV vs 8.42 (95% CI, 8.14-8.63) for OR. Sensitivity analysis showed that for younger patients, EV results in a higher increase in QALYs compared with older patients. Total expected reinterventions per patient are 1.70 for EV vs 0.30 for OR. Total expected health care costs for the reference-case patient were $39,942 (95% CI, $28,509-$53,380) for OR and $38.217 (95% CI, $29,329-$48,309) for EV. For men, this was $39,375 (95% CI, $28,092-$52,853) for OR and $35,903 (95% CI, $27,685-$45,597) for EV. For patients younger than 60 years, EV is a more expensive treatment strategy compared with OR, but with an incremental cost-effectiveness ratio for EV of less than $60,000/QALY. For patients 60 years and older, EV dominated OR as preferential treatment because effectiveness was higher than for OR and costs were lower. CONCLUSIONS: The results of this decision analysis model suggest that EV is favored over OR for patients with CMI in all age groups. Although EV is associated with more expected reinterventions, EV appears to be cost-effective for all age groups.

Asunto(s)

Técnicas de Apoyo para la Decisión , Procedimientos Endovasculares , Isquemia/cirugía , Enfermedades Vasculares/cirugía , Procedimientos Quirúrgicos Vasculares , Factores de Edad , Anciano , Anciano de 80 o más Años , Investigación sobre la Eficacia Comparativa , Simulación por Computador , Análisis Costo-Beneficio , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/economía , Procedimientos Endovasculares/mortalidad , Femenino , Costos de la Atención en Salud , Humanos , Isquemia/diagnóstico , Isquemia/economía , Isquemia/mortalidad , Isquemia/fisiopatología , Masculino , Cadenas de Markov , Isquemia Mesentérica , Persona de Mediana Edad , Selección de Paciente , Valor Predictivo de las Pruebas , Calidad de Vida , Años de Vida Ajustados por Calidad de Vida , Reoperación , Medición de Riesgo , Factores de Riesgo , Factores Sexuales , Factores de Tiempo , Resultado del Tratamiento , Enfermedades Vasculares/diagnóstico , Enfermedades Vasculares/economía , Enfermedades Vasculares/mortalidad , Enfermedades Vasculares/fisiopatología , Grado de Desobstrucción Vascular , Procedimientos Quirúrgicos Vasculares/efectos adversos , Procedimientos Quirúrgicos Vasculares/economía , Procedimientos Quirúrgicos Vasculares/mortalidad

RESUMEN

OBJECTIVE: The optimal treatment for patients with uncomplicated chronic Stanford type B aortic dissections (chTBADs) is still matter of debate. The purpose of this study was to design a decision tool to guide the surgeon in determining the preferred treatment option. METHODS: A Markov decision-analysis model compared chTBAD patients treated with initial open surgical repair (OSR), thoracic endovascular aortic repair (TEVAR), and optimal medical therapy (OMT), followed during follow-up by OSR (OMT-OSR) or TEVAR (OMT-TEVAR), if indicated. Procedural risks, aortic growth and rupture rates, outcomes, and quality of life values were derived from the best available evidence in the literature. A chTBAD treatment strategy decision tool was developed, including the four key variables of age, sex, surgical risk, and maximum initial aortic diameter. Primary outcome was quality-adjusted life-years (QALYs). RESULTS: For the reference patient cohort, 55-year-old men with chTBAD with a maximum aortic diameter of 5.0 cm, medium risk for surgery, and a threshold for surgery of 6.0 cm during follow-up, OSR yielded higher QALYs, with 10.06 QALYs (95% credibility interval [CI], 9.52-10.56 QALYs) vs 9.92 QALYs (95% CI, 9.23-10.58 QALYs) after TEVAR and 9.64 QALYs (95% CI, 9.38-9.88 QALYs) and 9.40 QALYs (95% CI, 9.11-9.69 QALYs) for OMT-OSR and OMT-TEVAR. The difference between OSR and OMT-OSR was 0.42 QALYs (95% CI, 0.01-0.81 QALYs) and between TEVAR and OMT-TEVAR was 0.52 QALYs (95% CI, 0.04-0.68 QALYs). This showed that intervention is preferred over OMT. A change of the four variables resulted in a change of preferred treatment. In general, OSR was the preferred treatment in younger patients with a larger aortic diameter and in low-risk patients. TEVAR was preferred in elderly patients with large aortic diameter and if the aortic diameter threshold for repair decreased. OMT was the optimal therapy in high-risk patients, elderly patients, or in patients with small aortic diameters. CONCLUSIONS: This decision-analysis model shows that there is no "one-size-fits-all" treatment for uncomplicated chTBADs. For the reference patient cohort, intervention is preferred over OMT. Age is the most important deciding factor, followed by initial aortic diameter. Immediate OSR is the preferred treatment option in younger patients with a large initial aortic diameter and in low-risk patients. Immediate TEVAR is preferred in elderly patients with a large initial aortic diameter and in patients with a lower threshold for OSR. OMT should be considered in high-risk patients, in patients with small initial aortic diameters, and in patients aged >80 years, unless their initial aortic diameter is >5.5 cm. However, the differences in some patient groups are clinically insignificant, allowing a major role for patient preferences and hospital-specific considerations. This clinical decision model may guide chTBAD treatment.

Asunto(s)

Aneurisma de la Aorta Torácica/terapia , Disección Aórtica/terapia , Técnicas de Apoyo para la Decisión , Años de Vida Ajustados por Calidad de Vida , Factores de Edad , Anciano , Disección Aórtica/patología , Disección Aórtica/cirugía , Angioplastia/efectos adversos , Aorta Torácica/patología , Aneurisma de la Aorta Torácica/patología , Aneurisma de la Aorta Torácica/cirugía , Simulación por Computador , Femenino , Humanos , Masculino , Cadenas de Markov , Persona de Mediana Edad , Medición de Riesgo , Factores de Riesgo , Factores Sexuales , Injerto Vascular/efectos adversos

RESUMEN

We report the use of Aptus HeliFX EndoAnchors for endovascular treatment of a proximal type I endoleak after previous endovascular aneurysm repair (EVAR) of a ruptured abdominal aortic aneurysm. An 81-year-old man had been treated with EVAR after a ruptured 12 × 11 cm abdominal aortic aneurysm. Standard computed tomographic angiography follow-up demonstrated a proximal type I endoleak. Because of the highly angulated neck and close position of the endograft to the renal arteries, placement of a proximal extension cuff was prohibited; therefore, the endoleak was treated with an alternative approach using the Aptus HeliFX EndoAnchors. Nine EndoAnchors were successfully placed circumferentially on the proximal site of the endograft. This successfully treated the endoleak by excluding the aneurysm sac from the circulation. Computed tomographic angiography follow-up after 3 months showed no residual type I endoleak. This case shows that placement of EndoAnchors can serve as a viable treatment option for proximal type I endoleaks after failed EVAR.

Asunto(s)

Aneurisma de la Aorta Abdominal/cirugía , Rotura de la Aorta/cirugía , Implantación de Prótesis Vascular/efectos adversos , Endofuga/cirugía , Procedimientos Endovasculares/efectos adversos , Grapado Quirúrgico/instrumentación , Suturas , Anciano de 80 o más Años , Aneurisma de la Aorta Abdominal/diagnóstico , Rotura de la Aorta/diagnóstico , Aortografía/métodos , Prótesis Vascular , Implantación de Prótesis Vascular/instrumentación , Endofuga/diagnóstico , Endofuga/etiología , Procedimientos Endovasculares/instrumentación , Humanos , Masculino , Reoperación , Stents , Tomografía Computarizada por Rayos X , Resultado del Tratamiento

RESUMEN

PURPOSE OF REVIEW: Ruptured descending thoracic aortic aneurysm (rDTAA) is a life-threatening disease. In the last decade, thoracic endovascular aortic repair (TEVAR) has evolved as a viable option and is now considered the preferred treatment for rDTAAs. New opportunities as well as new challenges are faced by both the surgeon and the anesthesiologist. This review describes the impact of current developments and new modalities for the surgical and anesthetic management of rDTAAs. RECENT FINDINGS: A collaborative approach between the anesthesiologist and surgeon during critical moments such as induction, moment of aortic occlusion and placement of the aortic stent-graft is mandatory. Important issues to consider on preoperative imaging evaluation are correct sizing of the aortic stent-graft and localization of the artery of Adamkiewicz. Emergency TEVAR should preferentially be started under local anesthesia and could be switched to general anesthesia after stent placement. Patients should be kept in permissive hypotension preoperatively and during the intervention before stent-graft deployment and relative hypertension after deployment. The use of a proactive spinal cord protection protocol could decrease the risk of spinal cord ischemia and/or paraplegia and consists of permissive hypertension after stent deployment, cerebrospinal fluid drainage to maintain adequate spinal cord perfusion, relative hypothermia and possibly use of mannitol. SUMMARY: In order to improve outcomes of TEVAR for rDTAA, a close communication between the anesthesiologist and the surgeon and a thorough understanding of the events during the procedure is mandatory. The use of a proactive spinal cord protection protocol may decrease the rates of devastating spinal cord ischemia.

Asunto(s)

Anestesia , Anestésicos , Aorta Torácica/cirugía , Aneurisma de la Aorta Torácica/cirugía , Procedimientos Endovasculares/métodos , Aneurisma Roto/cirugía , Aneurisma de la Aorta Torácica/diagnóstico , Delirio/prevención & control , Humanos , Monitoreo Intraoperatorio , Cuidados Posoperatorios , Complicaciones Posoperatorias/psicología , Complicaciones Posoperatorias/terapia , Cuidados Preoperatorios , Stents

RESUMEN

OBJECTIVE: Repair is indicated of asymptomatic popliteal artery aneurysms (aPAAs) that are >2 cm. Endovascular PAA repair with covered stents (stenting) is increasingly used. It is, however, unclear when an endovascular approach is preferred to traditional open repair with great saphenous vein bypass (GSVB). The goal of this study was to assess the treatment options for aPAAs using decision analysis. METHODS: A Markov model was developed and a hypothetic cohort of patients with aPAAs was analyzed. GSVB, stenting, and nonoperative management with optimal medical treatment (OMT) were compared. Operative mortality, patency rates, quality-of-life values, and costs were determined by comprehensive review of the best available evidence. The main outcome was quality-adjusted life-years (QALYs). Secondary outcomes were cost-effectiveness and number of reinterventions. RESULTS: For a 65-year-old male patient with a 2.0-cm aPAA and without significant comorbidities, probabilistic sensitivity analysis shows that intervention is preferred over OMT (5.77 QALYs, 95% credibility interval [CI], 5.43-6.11; OMT). GSVB treatment for this patient results in slightly higher QALYs than stent placement, with a predicted 8.43 QALYs (GSVB: 95% CI, 8.21-8.64) vs 8.07 QALYs (stenting: 95% CI, 7.84-8.29), a difference of 0.36 QALYs (95% CI, 0.14-0.58). Furthermore, costs are higher for stenting ($40,464; 95% CI, $34,814-$46,242) vs GSVB ($21,618; 95% CI, $15,932-$28,070), and more reinterventions are required after stenting (1.03 per patient) vs GSVB (0.52 per patient), making GSVB the preferred strategy for all outcomes considered. Stenting is preferred in patients who are at high risk for open repair (>6% 30-day mortality) or if the 5-year primary patency rates of stenting increase to 80%. For very old patients (>95 years) and patients with a very short life expectancy (<1.5 years), OMT yields higher QALYs. CONCLUSIONS: GSVB is the preferred treatment in 65-year-old patients with aPAAs for all outcomes considered. However, patients at high risk for open repair or without suitable vein should be considered as candidates for endovascular repair. Very elderly patients and patients with a short life expectancy are best treated with OMT. Further improvement of endovascular techniques that increase patency rates of endovascular stents could make this the preferred therapy for more patients in the future.

Asunto(s)

Aneurisma/cirugía , Técnicas de Apoyo para la Decisión , Procedimientos Endovasculares , Arteria Poplítea/cirugía , Vena Safena/trasplante , Anciano , Anciano de 80 o más Años , Aneurisma/diagnóstico , Aneurisma/economía , Aneurisma/mortalidad , Aneurisma/fisiopatología , Animales , Enfermedades Asintomáticas , Fármacos Cardiovasculares/uso terapéutico , Gatos , Simulación por Computador , Análisis Costo-Beneficio , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/economía , Procedimientos Endovasculares/instrumentación , Procedimientos Endovasculares/mortalidad , Costos de Hospital , Humanos , Masculino , Cadenas de Markov , Método de Montecarlo , Selección de Paciente , Arteria Poplítea/fisiopatología , Calidad de Vida , Años de Vida Ajustados por Calidad de Vida , Factores de Riesgo , Stents , Resultado del Tratamiento , Grado de Desobstrucción Vascular

RESUMEN

Single-molecule defocused wide-field imaging (DWFI) has been demonstrated to be useful to determine molecular structure parameters, such as the orientations of transition dipole moments and the angular relationships between chromophores in multichromophoric molecular systems. For a series of acetylene-linked perylene bisimide (PBI) macrocycles with different ring size comprising three to six PBI dyes, we reconstructed the molecular structure of the multichromophoric system using DWFI method. Furthermore, we revealed that the structural heterogeneities and distortions depend on the ring size. Our findings illustrate the use of DWFI to gain deeper insight into the structure-property relationships of artificial light-harvesting molecular systems.

Asunto(s)

Aorta Torácica/cirugía , Aneurisma de la Aorta Torácica/cirugía , Disección Aórtica/cirugía , Rotura de la Aorta/cirugía , Implantación de Prótesis Vascular/métodos , Procedimientos Endovasculares/métodos , Arteria Subclavia/cirugía , Femenino , Humanos , Masculino

Asunto(s)

Aneurisma de la Aorta Abdominal/cirugía , Rotura de la Aorta/cirugía , Implantación de Prótesis Vascular , Endofuga/cirugía , Procedimientos Endovasculares , Femenino , Humanos , Masculino

RESUMEN

Properties of a series of acetylene-linked perylene bisimide (PBI) macrocycles with different ring size composed of three to six PBI dyes were investigated by atomic force microscopy (AFM) and single-molecule fluorescence spectroscopy in a condensed phase. It was demonstrated that the structures of PBI cyclic arrays (CNs, N = 3, 4, 5, and 6) become distorted with increasing the ring size through molecular dynamics (MD) simulations (PM6-DH2 method) and AFM height images of CNs on highly ordered pyrolytic graphite (HOPG) surface. The MD simulations showed that only C5 and C6 rings are highly flexible molecules whose planarization goes along with a significant energetic penalty. Accordingly, both molecules did not show ordered adlayers on a HOPG surface. In contrast, C3 and C4 are far more rigid molecules leading to well-ordered hexagonal (C3) and rectangular (C4) 2D lattices. At the single-molecule level, we showed that the fluorescence properties of single CNs are affected by the structural changes. The fluorescence lifetimes of CNs became shorter and their distributions became broader due to the structural distortions with increasing the ring size. Furthermore, the CNs of smaller ring size exhibit a higher photostability and an efficient excitation energy transfer (EET) due to the more well-defined and planar structures compared to the larger CNs. Consequently, these observations provide evidence that not only PBI macrocycles are promising candidates for artificial light-harvesting systems, but also the photophysical properties of CNs are strongly related to the structural rigidity of CNs.