RESUMEN
BACKGROUND AIMS: Immunotherapy with allodepleted donor T cells improves immunity after T cell-depleted hematopoietic stem cell transplantation. We developed a methodology for selective depletion of alloreactive T cells after activation with host antigen-presenting cells by targeting T cells up-regulating CD25 and CD71. Combined depletion of these cells yields a pool of allodepleted donor T cells with antiviral properties with minimal capacity to cause graft-versus-host disease. METHODS: Mature dendritic cells were irradiated and used to stimulate donor peripheral blood mononuclear cells for 4 days. The co-culture was stained with anti-CD71-biotin followed by CliniMACS CD25 and Anti-Biotin Reagents (Miltenyi Biotec GmbH; Bergisch Gladbach, Germany) before depletion on the CliniMACS Plus (Miltenyi Biotec GmbH). Residual alloreactivity was tested by flow cytometry, a secondary mixed lymphocyte reaction and limiting dilution analysis, and specific anti-viral immunity with pentamer staining. The large-scale protocol was tested under current good manufacturing practice conditions in five donor-recipient pairs of human leukocyte antigen-matched volunteer donors. RESULTS: We developed a closed-system methodology using cell differentiation bags for cell culture and the COBE2991 Cell Processor (CaridianBCT, Lakewood, CO, USA). We also validated an anti-CD71-biotin generated for ex vivo clinical use. In five large-scale runs, the depleted fraction demonstrated excellent viability (99.9%), minimal residual expression of CD3/CD25 and CD3/CD71 (<0.2%) and passed tests for Mycoplasma, endotoxin, bacterial and fungal sterility. In secondary mixed lymphocyte reaction assays, the median response to host after allodepletion was 0%, whereas responses to third-party peripheral blood mononuclear cells were preserved (median, 105%; range 37%-350%). Limiting dilution analysis assays also demonstrated a reduction in response to host (median, -1.11 log) with preservation of third-party responses, and testing with human leukocyte antigen-restricted pentamers showed that populations of Epstein-Barr virus-specific and cytomegalovirus-specific CD8(+) T cells were retained after depletion. CONCLUSIONS: We optimized a protocol for the combined immunomagnetic depletion of alloreactive CD25/CD71 T cells under current good manufacturing practice conditions and tested the efficacy in five donor-recipient pairs.
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Antígenos CD/metabolismo , Técnicas de Cultivo de Célula/métodos , Células Dendríticas/inmunología , Subunidad alfa del Receptor de Interleucina-2/metabolismo , Depleción Linfocítica , Receptores de Transferrina/metabolismo , Linfocitos T/citología , Linfocitos T/metabolismo , Células Cultivadas , Técnicas de Cocultivo , Citometría de Flujo , Enfermedad Injerto contra Huésped/inmunología , Trasplante de Células Madre Hematopoyéticas , Humanos , Leucocitos Mononucleares/inmunologíaRESUMEN
PURPOSE: To describe a technique for transapical wire-assisted endograft deployment under rapid ventricular pacing for a type B dissection involving the proximal left subclavian artery and extending to the aortic bifurcation. CASE REPORT: A 58-year-old man presented with a symptomatic thoracic aneurysm as a complication of a chronic type B dissection, with a short proximal neck in zone 1. After arch vessel debranching, the patient underwent endoluminal repair with deployment of a closed web, tapered Valiant thoracic endograft over a through-and-through wire from the left groin to the apex of the left ventricle, using rapid ventricular pacing to reduce cardiac output. The remaining dissected aorta was covered with a second Valiant endograft down to the distal third of the descending thoracic aorta and bare Z stents down to the aortic bifurcation to re-expand the true lumen. A freeflow Valiant endograft was deployed as a proximal extension to treat a proximal type I endoleak. The recovery was complicated by retrograde type A aortic dissection, considered secondary to the bare stent. The complication was repaired surgically; postoperative computed tomography after recovery was unremarkable. CONCLUSION: Transapical wire-assisted deployment with rapid ventricular pacing is feasible and may provide improved stability for stenting within the aortic arch. The use of a stent-graft with a proximal bare stent is associated with a higher risk of retrograde extension of the dissection and warrants lifelong imaging follow-up.
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Aneurisma de la Aorta Torácica/cirugía , Disección Aórtica/cirugía , Implantación de Prótesis Vascular , Procedimientos Endovasculares , Disección Aórtica/diagnóstico por imagen , Disección Aórtica/fisiopatología , Aneurisma de la Aorta Torácica/diagnóstico por imagen , Aneurisma de la Aorta Torácica/fisiopatología , Aortografía/métodos , Prótesis Vascular , Implantación de Prótesis Vascular/efectos adversos , Implantación de Prótesis Vascular/instrumentación , Gasto Cardíaco , Estimulación Cardíaca Artificial , Procedimientos Endovasculares/efectos adversos , Procedimientos Endovasculares/instrumentación , Humanos , Masculino , Persona de Mediana Edad , Diseño de Prótesis , Stents , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
INTRODUCTION: Prosthetic arteriovenous grafts (AVGs) in the lower extremity represent a useful alternative for hemodialysis vascular access when all upper limb access sites have been used or in some patients when freedom of both hands is necessary during dialysis. Reported complications include an increased risk of infection and limb ischemia. This study evaluated our experience with the patency outcomes and complication rates of polytetrafluoroethylene (PTFE) AVGs placed in the thigh. METHODS: A retrospective outcomes analysis was performed of all femoral AVGs inserted between January 1992 and July 2007. Data were obtained by review of medical records for patient demographics, comorbidities, and AVG-related outcomes. Patency, complication rates, and risk factors for infection were determined. RESULTS: A total of 153 prosthetic AVGs were placed in 127 patients (63 men). Mean patient age was 52.7 ± 16.3 years. Median follow-up was 25 months (range, 1-169 months). The most common underlying renal disease was glomerulonephritis in 27 (21%). Hypertension and coronary artery disease were common comorbidities, respectively, in 49 (39%) and 23 patients (18%). The primary and secondary AVG patency rates at 12 months were 53.9% and 75.3%, respectively, and 2- and 5-year patency rates were, respectively, 39.6% and 19.3% (primary) and 63.8% and 50.6% (secondary). The mean AVG survival for all cases was 31.6 months (range, 0-149 months). Surgical thrombectomy was required in 82 (54%), and 22 AVGs (14%) required surgical revision for stenosis. Infection occurred in 41 AVGs (27%), and limb ischemia occurred in 2 (1.3%). Statistical analysis did not reveal a significant risk factor for infection. CONCLUSIONS: Femoral AVGs are a suitable alternative to upper limb vascular access, with acceptable primary and secondary patency rates. Infection occurred in approximately one-quarter of cases, whereas steal was uncommon.
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Derivación Arteriovenosa Quirúrgica , Prótesis Vascular , Infecciones Relacionadas con Prótesis/etiología , Diálisis Renal , Grado de Desobstrucción Vascular , Derivación Arteriovenosa Quirúrgica/efectos adversos , Prótesis Vascular/efectos adversos , Femenino , Arteria Femoral , Vena Femoral , Humanos , Estimación de Kaplan-Meier , Extremidad Inferior , Masculino , Persona de Mediana Edad , Politetrafluoroetileno , Factores de Riesgo , Trombosis/etiologíaRESUMEN
The development of an ideal small-diameter conduit for use in vascular bypass surgery has yet to be achieved. The ongoing innovation in biomaterial design generates novel conduits that require preclinical assessment in vivo, and a number of animal models have been used for this purpose. This article examines the rationale behind animal models used in the assessment of small-diameter vascular conduits encompassing the commonly used species: baboons, sheep, pigs, dogs, rabbits, and rodents. Studies on the comparative hematology for these species relative to humans are summarized, and the hydrodynamic values for common implant locations are also compared. The large- and small-animal models are then explored, highlighting the characteristics of each that determine their relative utility in the assessment of vascular conduits. Where possible, the performance of expanded polytetrafluoroethylene is given in each animal and in each location to allow direct comparisons between species. New challenges in animal modeling are outlined for the assessment of tissue-engineered graft designs. Finally, recommendations are given for the selection of animal models for the assessment of future vascular conduits.
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Materiales Biocompatibles , Implantación de Prótesis Vascular/instrumentación , Prótesis Vascular , Ensayo de Materiales/métodos , Modelos Animales , Animales , Perros , Hemodinámica , Hemostasis , Humanos , Ratones , Papio , Diseño de Prótesis , Conejos , Ratas , Reproducibilidad de los Resultados , Ovinos , Especificidad de la Especie , PorcinosRESUMEN
Common bile duct stenosis owing to extrahepatic portal varices is termed "portal hypertensive biliopathy" (PHB) and is a rare occurrence. We report a case of PHB owing to portal vein thrombosis with cavernous transformation successfully managed by mesocaval shunt and endoscopic retrograde cholangiopancreatography (ERCP) biliary stent placement. A 44-year-old male, who presented with hematemesis, melena, jaundice, and abdominal pain, underwent gastroscopy, which revealed bleeding gastric varices. Computed tomography with arterial and venous imaging demonstrated portal vein thrombosis with cavernous transformation and extensive extrahepatic varices within the porta hepatis causing common bile duct obstruction from extrinsic compression. Biliary decompression was achieved with ERCP, and a small common bile duct stone was retrieved. A mesocaval shunt with a 16 mm Dacron graft successfully treated the portal hypertension. PHB is rare. We report a case successfully treated by mesocaval shunt and ERCP.
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Colestasis Extrahepática/etiología , Hipertensión Portal/complicaciones , Vena Porta , Stents , Várices/complicaciones , Adulto , Implantación de Prótesis Vascular , Colangiopancreatografia Retrógrada Endoscópica , Colestasis Extrahepática/diagnóstico por imagen , Colestasis Extrahepática/cirugía , Conducto Colédoco/diagnóstico por imagen , Conducto Colédoco/cirugía , Humanos , Hipertensión Portal/diagnóstico por imagen , Hipertensión Portal/cirugía , Masculino , Vena Porta/diagnóstico por imagen , Prohibitinas , Tomografía Computarizada por Rayos X , Várices/diagnóstico por imagen , Várices/cirugíaRESUMEN
BACKGROUND: Surgical therapy for the thoracic aorta carries a high morbidity and mortality. Endovascular therapy for aneurysms and its adaptation to the thoracic aorta over the past 10 years is an exciting advance. This is a retrospective review of endovascular grafting of the thoracic aorta during the past decade at Royal Prince Alfred Hospital and the outcomes achieved over this period. METHODS: A retrospective review of all patients at our institution who underwent endovascular grafting of the thoracic aorta between March 1995 and March 2005 was carried out. Data were analysed using Stata version 8.0 (Stata corporation, College Station, TX, USA). RESULTS: Sixty-five patients underwent endovascular stent grafting of the thoracic aorta. The indications were degenerative aneurysm (31), Stanford type B dissection (23) both acute (12) and chronic (11), traumatic transection (9) and penetrating ulcer (2). There were no conversions to open repair. Twenty-two patients required additional procedures, six of which were unplanned. The median age was 65 (range 18-85), 68% of patients were men. The median procedure time was 115 min (range 55-240 min). Mean hospital stay was 9.8+/-7.3 days and high dependency/intensive care unit stay 1.5+/-3.2 days. Thirty-day mortality was 0 in 41 for elective cases (one patient (2.5%) died 37 days post-procedure) and 12% (3 of 25) for emergency cases. Complications occurred in 20 of 41 (49%) elective cases and 14 of 24 (58%) emergency cases within the first 30 days. The most frequent major complications were neurological including paraplegia (transient 2 of 65, permanent (2 of 65)) and stroke (4 of 65). Other complications included endoleak (12 of 65), acute renal failure (1 of 65), and brachial artery false aneurysm (1 of 65). The mean length of follow up was 22.5 months (range, 1-97 months). Six patients required further endovascular procedures for persistent endoleak or ongoing perfusion of chronic dissection. Late deaths (>30 days) related to the endovascular treatment occurred in two patients (3%). CONCLUSION: Endovascular grafting of the thoracic aorta is an evolution in the treatment of thoracic aortic pathology. The results of elective endovascular grafts were acceptable. Emergency procedures had a higher incidence of complications and death. Improvement in graft technology, design and deployment are required.
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Aneurisma de la Aorta Torácica/cirugía , Implantación de Prótesis Vascular/métodos , Aneurisma de la Aorta Torácica/diagnóstico por imagen , Aortografía , Medios de Contraste , Femenino , Fluoroscopía , Humanos , Yohexol/análogos & derivados , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Estudios Retrospectivos , Stents , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
OBJECTIVE: The potentially devastating complication of total or near total thoracic endoprosthesis collapse has been described with the TAG device (W. L. Gore & Associates, Flagstaff, Ariz). This rare complication has resulted in a warning to clinicians and speculation about the etiology of this problem. This report evaluates potential causative anatomic factors that may increase the probability of endoprosthesis collapse in patients undergoing endovascular thoracic aneurysm repair (TEVAR). METHODS: Preoperative and postoperative computed tomography scans were collected worldwide representing six patients who had experienced radiologically confirmed TAG endoprosthesis collapse. These were compared with a matched cohort of five patients with a TAG endoprosthesis in the same anatomic position in which no collapse occurred. Anatomic variables of aortic arch angulation, apposition, intraluminal lip length, proximal aortic diameter, distal aortic diameter, intragraft aortic diameter, percentage of oversizing, and angle of the proximal endograft to the aortic arch were compared between groups. Differences between groups were determined using the Student t test, with P < .05 considered significant. RESULTS: The two groups (collapse vs no collapse) were evenly matched demographically, and all underwent endoluminal treatment with the TAG device, with no differences in gender, graft position in the aorta, operative indication, or age (P = NS). Distal sealing zone aortic diameter +/- standard deviation of 18.9 +/- 1.7 mm vs 22.7 +/- 2.7 mm and minimum aortic diameter within the endograft of 18.6 +/- 1.7 mm vs 22.4 +/- 3.1 mm predicted collapse (P < .05). Proximal aortic diameter, apposition, intraluminal lip length, aortic arch angle, and angle of proximal endograft to aortic arch did not predict collapse (P = NS). CONCLUSION: Thoracic endograft collapse is an exceedingly rare event. In this series, endoprosthesis collapse occurred in patients who were treated outside the manufacturer's instructions for use for minimum required aortic diameter. Although distal aortic diameter and minimum intragraft aortic diameter predicted collapse, other variables may also influence this complication but were not significant owing to potential type II statistical errors. In the future, caution should be exercised when contemplating TEVAR in patients with small (<23 mm) aortic diameters.
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Aneurisma de la Aorta Torácica/cirugía , Disección Aórtica/cirugía , Rotura de la Aorta/cirugía , Implantación de Prótesis Vascular/instrumentación , Falla de Prótesis , Disección Aórtica/diagnóstico por imagen , Aorta Torácica/diagnóstico por imagen , Aorta Torácica/cirugía , Aneurisma de la Aorta Torácica/diagnóstico por imagen , Rotura de la Aorta/diagnóstico por imagen , Aortografía , Estudios de Casos y Controles , Cineangiografía , Estudios de Cohortes , Adhesión a Directriz , Humanos , Selección de Paciente , Guías de Práctica Clínica como Asunto , Valor Predictivo de las Pruebas , Diseño de Prótesis , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
BACKGROUND: Bypass for extra-cranial arterial disease is infrequently carried out. We reviewed our experience to determine the outcome of carotid artery grafting using either an autogenous vein or polytetrafluoroethylene (PTFE). METHODS: Details of patients were recorded prospectively as part of a vascular surgical registry. Patients identified from the registry as having carotid artery bypass procedures were classified according to the type of conduit used. Comparison was made between patients with autogenous vein and PTFE grafts. RESULTS: Between 1978 and 2002, 24 patients (13 men and 11 women) mean age 60.0 +/- 13.4 years (range, 20-81 years) underwent 28 bypass procedures (three were bilateral and one was a reoperation). Symptomatic carotid disease was the clinical indication in 20 of 28 procedures (71.4%). Pathological indications included advanced atherosclerosis of the carotid arteries (15), past radiotherapy (4), failed stenting (3), resection of carotid body tumour (2), trauma (1), reoperation on a failed graft (1), carotid aneurysm (1) and iatrogenic carotid occlusion (1). An autogenous vein was used in 16, PTFE in 11 and autogenous artery in 1 of the patients. Using the Kaplan-Meier method, the overall patient cumulative 5-year survival was 84% and cumulative 5-year stroke-free survival was 93%. The combined perioperative stroke and mortality rate was 7.1%. Two patients had transient ischaemic attacks (7.1%), one had cranial nerve palsies (3.6%) and one required reoperation for bleeding (3.6%). Five-year cumulative graft primary patency using the Kaplan-Meier method was 74% for PTFE grafts and 92% for autogenous vein grafts (P = 0.37). CONCLUSION: Carotid artery bypass is a safe and a useful treatment option for complex extra-cranial arterial disease. Either PTFE or autogenous veins may be used as conduits.
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Prótesis Vascular , Arterias Carótidas/cirugía , Enfermedades de las Arterias Carótidas/cirugía , Politetrafluoroetileno , Venas/trasplante , Adulto , Anciano , Anciano de 80 o más Años , Arterias Carótidas/fisiología , Enfermedades de las Arterias Carótidas/mortalidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Reoperación , Stents , Tasa de Supervivencia , Trasplante AutólogoRESUMEN
Type II endoleaks after endovascular repair of abdominal aortic aneurysm (EVAR) are a result of retrograde flow from arterial branches (e.g., lumbar and inferior mesenteric) refilling the aneurysm sac, which has been excluded by the stent graft. Controversy continues with regard to the clinical significance and treatment of type II endoleaks. To develop recommendations for management, we analyzed outcome data from 10 EVAR trials completed over the last 5 years involving a total of 2,617 cases. The incidence of type II endoleak at discharge or 30 days was 6-17%, at 6 months 4.5-8%, and at 1 year 1-5%. Successful resolution of endoleak following secondary interventions was observed in 11-100% of cases. There were 10 conversions to open repair and no ruptures related to type II endoleak. In patients observed for 12 months with computed tomography and/or ultrasound, approximately one-half of type II endoleaks disappeared spontaneously. In the absence of a type I endoleak, our analysis of the current literature suggests that intervention for type II endoleak should be undertaken for abdominal aortic aneurysm sac enlargement occurring after 6 months, persistence for >12 months without abdominal aortic aneurysm sac enlargement, or an aneurysm sac pressure >20% of systolic blood pressure; translumbar aneurysm sac thrombosis and intra-arterial feeding vessel occlusion appear to be prudent management options.
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Aneurisma de la Aorta Abdominal/cirugía , Implantación de Prótesis Vascular , Embolización Terapéutica , Complicaciones Posoperatorias/terapia , Adulto , Anciano , Anciano de 80 o más Años , Aneurisma de la Aorta Abdominal/patología , Ensayos Clínicos como Asunto , Estudios de Seguimiento , Humanos , Persona de Mediana Edad , StentsRESUMEN
BACKGROUND: Diastolic counterpulsation has been used to provide circulatory augmentation for chronic heart failure or for short-term cardiac support. Recently an extra-aortic balloon (EAB) counterpulsation device has been proposed. AIM: To compare the circulatory effects of counterpulsation using the EAB or an intra-aortic balloon (IAB) in the acute pig model. METHODS: In six anaesthetized great white pigs (paced at 100 bpm), ECG, arterial and central venous pressures, flow in the coronary circulation and descending thoracic aorta were measured. Baseline data was collected, then with the EAB or an IAB fitted using 1:1 and 1:2 counterpulsation modes. Baseline data was compared to EAB and IAB data in 1:1 mode. Assisted beat data compared to unassisted beat data was also analysed in 1:2 mode. RESULTS: Both devices augmented peak diastolic arterial pressure, and decreased afterload. EAB counterpulsation increased diastolic coronary flow in both the 1:1 mode by 69% (p < 0.05) and in the 1:2 mode by 63% (assisted versus unassisted beat, p < 0.05). The IAB significantly increased diastolic coronary flow only in the 1:2 mode by 28% (p < 0.01). Both devices augmented total coronary flow and some augmentation of aortic flow was observed. CONCLUSION: The circulatory effect of the EAB and IAB counterpulsation were comparable. This suggests the EAB could be used as a non-blood contacting heart assist device in patients suffering moderate-severe heart failure.
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Velocidad del Flujo Sanguíneo/fisiología , Vasos Coronarios/fisiopatología , Insuficiencia Cardíaca/terapia , Contrapulsador Intraaórtico/instrumentación , Animales , Vasos Coronarios/diagnóstico por imagen , Modelos Animales de Enfermedad , Diseño de Equipo , Insuficiencia Cardíaca/fisiopatología , Porcinos , Ultrasonografía DopplerAsunto(s)
Aneurisma de la Aorta Torácica/cirugía , Implantación de Prótesis Vascular/efectos adversos , Prótesis Vascular/efectos adversos , Hipertensión/etiología , Adolescente , Adulto , Anciano , Antihipertensivos/uso terapéutico , Aneurisma de la Aorta Torácica/diagnóstico por imagen , Aortografía , Implantación de Prótesis Vascular/métodos , Estudios de Seguimiento , Humanos , Hipertensión/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico , Medición de Riesgo , Muestreo , Traumatismos Torácicos/diagnóstico , Traumatismos Torácicos/cirugía , Tomografía Computarizada por Rayos X , Resultado del TratamientoRESUMEN
PURPOSE: To report thoracic aortic stent-graft repair in a patient with abnormal aortic arch anatomy. CASE REPORT: An anomalous right subclavian artery was covered with a stent-graft in a 38-year-old woman being treated for a false aneurysm after coarctation repair. The right arm became relatively ischemic, but was viable and managed conservatively. CONCLUSIONS: Aneurysms close to left or aberrant right subclavian arteries can be safely and effectively treated by endoluminal repair without the need for revascularization procedures; ischemic symptoms that develop are often mild and transient.
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Aneurisma de la Aorta Torácica/cirugía , Brazo/irrigación sanguínea , Implantación de Prótesis Vascular/efectos adversos , Isquemia/etiología , Isquemia/terapia , Stents/efectos adversos , Adulto , Aorta Torácica/anomalías , Aorta Torácica/cirugía , Aneurisma de la Aorta Torácica/diagnóstico por imagen , Aortografía , Oclusión con Balón/métodos , Implantación de Prótesis Vascular/métodos , Femenino , Estudios de Seguimiento , Humanos , Isquemia/diagnóstico por imagen , Medición de Riesgo , Arteria Subclavia/anomalías , Arteria Subclavia/diagnóstico por imagen , Arteria Subclavia/cirugía , Resultado del TratamientoRESUMEN
OBJECTIVE: The purpose of this single-center study was to compare findings at presentation and surgical outcome in patients in whom abdominal aortic aneurysms (AAAs) ruptured after endovascular repair and patients in whom AAAs ruptured before any treatment, over a defined period. METHODS: From May 1992 to September 2003, 1043 patients underwent elective repair of intact infrarenal AAAs. Endovascular repair was performed in 609 patients, and open repair in 434 patients. Eighteen of 609 patients (3%) who underwent endovascular AAA repair required treatment because of rupture of the aneurysm after a mean of 29 months (group 1). During the same 11-year period, another 91 patients without previous treatment required urgent repair of a ruptured AAA (group 2). Rupture was diagnosed at contrast material-enhanced computed tomography or by presence of extramural extravasation of blood at open repair. Except for a higher incidence of women in group 2, patients in both groups were similar with regard to demographics and clinical characteristics but differed in findings at presentation. Eight patients in group 1 had a known endoleak before AAA rupture, whereas contrast-enhanced computed tomography, performed in 15 patients at presentation, demonstrated an endoleak in all. Hypotension (systolic blood pressure <100 mm Hg) was noted at presentation in 4 of 18 patients (22%) in group 1 and 76 of 91 patients (84%) in group 2. All patients underwent open repair via a transperitoneal approach, except for 4 patients in group 1 and 3 patients in group 2 who underwent endovascular repair of ruptured AAAs. RESULTS: The proportion of patients with hypotension at presentation in group 1 (4 of 18) was significantly less than in group 2 (76 of 91; P < .01). The difference in perioperative (30 day) mortality rate in group 1 (3 of 18; 16.6%) compared with group 2 (49 of 91; 53.8%) was also significant (P < .01). The outcome in group 1 was therefore superior to that in group 2. CONCLUSIONS: This study confirms that endovascular AAA repair complicated by endoleak does not prevent rupture. The data suggest, however, that rupture, when it occurs in these circumstances, may not be accompanied by such major hemodynamic changes and high mortality as rupture of an untreated AAA. Further long-term follow-up and analysis in a larger group of patients are required to confirm the apparent intermediate level of protection afforded by failed endovascular repair, which does not prevent rupture but enhances survival after operation to treat rupture, possibly by ameliorating the hemodynamic changes associated with the rupture process.
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Aneurisma Roto/mortalidad , Aneurisma Roto/cirugía , Aneurisma de la Aorta Abdominal/mortalidad , Aneurisma de la Aorta Abdominal/cirugía , Implantación de Prótesis Vascular/métodos , Factores de Edad , Anciano , Anciano de 80 o más Años , Aneurisma Roto/diagnóstico por imagen , Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Aortografía , Australia , Implantación de Prótesis Vascular/efectos adversos , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Mínimamente Invasivos/efectos adversos , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Probabilidad , Estudios Retrospectivos , Medición de Riesgo , Índice de Severidad de la Enfermedad , Factores Sexuales , Estadísticas no Paramétricas , Análisis de Supervivencia , Factores de Tiempo , Resultado del Tratamiento , Procedimientos Quirúrgicos Vasculares/efectos adversos , Procedimientos Quirúrgicos Vasculares/métodosRESUMEN
BACKGROUND: Equipoise is defined medically as a state of genuine uncertainty about the relative benefits of alternative treatment options. This study investigated individual and collective equipoise among vascular surgeons for controversial clinical questions to assess the feasibility of conducting randomized controlled trials. METHODS: Vascular surgeons throughout Australia and New Zealand received a survey by mail. RESULTS: Vascular surgeons (n=146, 77% response fraction) were able to quantify the strength of their treatment preferences and did so differentially between clinical scenarios using a simple scale. Almost one quarter (24%; 95% CI, 18%-32%) were completely undecided about whether carotid endarterectomy or carotid stenting was preferable to treat carotid stenosis in high-risk patients, indicating individual equipoise. In contrast, the vast majority of respondents (89%; 95% CI, 82%-93%) favored carotid endarterectomy over carotid stenting for average-risk patients, suggesting lack of community equipoise for this patient group. Similarly, there was lack of community equipoise for treatments for abdominal aortic aneurysm in high-risk patients with 88% (95% CI, 81%-92%) favoring a minimally invasive approach. Older respondents were consistently less willing to take part in randomized trials, with strength of treatment preference also independently predicting willingness to participate in 4 of 6 trials. CONCLUSIONS: Individual and community equipoise can be measured in a representative sample of surgeons as part of the feasibility assessment for future randomized controlled trials.
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Médicos , Ensayos Clínicos Controlados Aleatorios como Asunto/normas , Procedimientos Quirúrgicos Vasculares/métodos , Adulto , Anciano , Australia , Estudios de Factibilidad , Femenino , Geografía , Humanos , Masculino , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Encuestas y CuestionariosRESUMEN
BACKGROUND: The paper is based on a case study, which was part of a Department of Health commissioned research study covering 10 National Health Service (NHS) trusts in England that had adopted a range of approaches to the employment terms and conditions of nurses, midwives, and other non-medical staff, as the precursor to evaluating Agenda for Change, the modernized pay system for the NHS. AIM: The aim of this paper is to discuss a case study of the effects of changing nurses' pay progression. METHODS: Fieldwork took place in 2000, and included interviews with managers, union representatives and other staff, and analysis of internal documents. FINDINGS: Findings discussed include the constraints on managers when devising a new pay system, the time and detailed work needed and the challenges of assessing their effects (particularly in relation to patient care). Although the latter are difficult to assess, staff involved in the scheme reported benefits from the closer focus on competences which resulted from the scheme. CONCLUSIONS: The effects of changes to pay schemes are difficult to assess, and the evaluation of the proposed national scheme (Agenda for Change) will be challenging.
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Reforma de la Atención de Salud/economía , Servicio de Enfermería en Hospital/economía , Personal de Enfermería/economía , Salarios y Beneficios , Reforma de la Atención de Salud/organización & administración , Humanos , Admisión y Programación de Personal , Desarrollo de Programa , Medicina Estatal/economía , Reino UnidoRESUMEN
OBJECTIVE: Endoluminal repair of abdominal aortic aneurysm (AAA) is predicated on stability of the proximal neck of the aneurysm. Reports on morphologic changes in the proximal neck after endoluminal repair of AAA have thus far been limited in duration to 3 years or less. The aim of this study was to document changes in diameter of the proximal neck of AAA in a group of patients who had undergone endoluminal repair between 5 and 9 years previously. METHODS: Between May 1992 and December 1996, 61 patients with AAA were treated with endoluminal repair by the senior author. The following patients were excluded from the study group: those requiring primary conversion to open repair at the original operation (n = 8), those with false aneurysm (n = 1), and those with dissection in the proximal neck (n = 1). Fifty-one patients (48 men and three women) with a mean age of 71 years remained in the study group. The endoprostheses used were modified Parodi (n = 4), Endovascular Technologies (n = 14), White-Yu (n = 10), Stentor/Vanguard (n = 21), and Bard 1996 prototype (n = 2). Morphologic changes in the proximal aortic neck were studied with contrast computed tomographic scan with the methodology recommended by the Ad Hoc Committee for Standardized Reporting Practices for Endovascular AAA Repair (revised version). The maximum transverse diameter of the proximal neck was measured 1 cm below the most inferior renal artery. A Kaplan-Meier analysis was performed showing the proportion of patients at risk with a demonstrated enlargement of the neck at each interval of time compared with the predischarge computed tomographic scan. A longitudinal study of morphologic changes in the proximal aortic neck was also undertaken in 28 patients with successful endoluminal repair who survived 5 years. RESULTS: The Kaplan-Meier curve showed a probability of no dilatation of the proximal neck of 0.943 at 7 years after endoluminal AAA repair. Of 28 patients with 5 years of follow-up after discharge, only two had increases in the diameter of the proximal neck greater than 2 mm. The endograft in both patients had undergone migration before any proximal neck dilation. A paired t test showed that the overall average increase of 0.4 mm (standard error, 0.3 mm) in these 28 patients was not statistically significant (P =.23). CONCLUSION: A high probability (0.943 at 7 years) exists of no enlargement of the proximal neck of AAA after endoluminal repair. We hypothesize that endografts positioned correctly immediately below the renal arteries protect the proximal neck from dilatation in a manner that does not occur after open repair of AAA.
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Aneurisma de la Aorta Abdominal/patología , Aneurisma de la Aorta Abdominal/terapia , Anciano , Prótesis Vascular , Dilatación Patológica , Femenino , Estudios de Seguimiento , Humanos , Tablas de Vida , Estudios Longitudinales , MasculinoRESUMEN
The two-electrode voltage-clamp technique was used to evaluate the effect of protein kinase C (PKC) activation on ion current flow in Xenopus laevis oocytes injected with cRNA coding for the human vanilloid receptor (VR1). In the presence of 30 nM phorbol-12,13-dibutyrate (PDBu), current evoked by an effective concentration (EC(30)) of capsaicin (CAP) was potentiated by 638+/-117% (n=8). PDBu exhibited an EC(50) of about 17+/-3 nM for this effect (n=8). Potentiation was not observed when VR1 expressing oocytes were exposed to both 30 nM PDBu and 1 microM staurosporine. In the presence of 300 nM PDBu, the EC(50) for CAP shifted from 899+/-78 to 139+/-2 1 nM (n=11 and 5, respectively). In the presence of 30 nM PDBu, the maximal current amplitude evoked by application of CAP increased by 86+/-21% (n=10), in a staurosporine sensitive manner. Application of 1 microM PDBu alone elicited a capsazepine sensitive current within 3 min of exposure. This effect was observed in the absence of previous exposure of the oocyte to CAP and was abolished in the presence of 1 microM staurosporine. No current was elicited during a 10 min application of 300 nM PDBu, the longest interval assessed. Prior to 30 nM PDBu exposure, no current was evoked at temperature ramps from room temperature (22-23 degrees C) up to 37 degrees C at pH 6.8, 7.0, or 7.4. Following PDBu treatment, VR1 mediated current was evoked at 26 degrees C at pH 7.0. Likewise, following 30 nM PDBu treatment, current was evoked by application of pH 6.8 alone and a further increase in current amplitude was evoked by heat at 24 degrees C in a staurosporine sensitive manner. These data provide direct evidence that PKC activation can increase VR1 current evoked by candidate physiological activators, pH and heat. This observation provides an empirical foundation for explaining some types of inflammatory pain in terms of PKC activation, small decreases in tissue pH levels, and small increases in skin temperature, all of which can accompany inflammatory conditions.
Asunto(s)
Capsaicina/farmacología , Hidrógeno/metabolismo , Proteína Quinasa C/metabolismo , Receptores de Droga/efectos de los fármacos , Temperatura , Animales , Electrofisiología , Activación Enzimática/fisiología , Femenino , Humanos , Concentración de Iones de Hidrógeno , Oocitos , Receptores de Droga/fisiología , Xenopus laevisRESUMEN
OBJECTIVE: Endoleaks and endotension are critically important complications of some endovascular aortic aneurysm repairs (EVARs). For the resolution of controversial issues and the determination of areas of uncertainty relating to these complications, a conference of 27 interested leaders was held on November 20, 2000. METHODS: These 27 participants (21 vascular surgeons, five interventional radiologists, one cardiologist) had previously answered 40 key questions on endoleaks and endotension. At the conference, these 40 questions and participant answers were discussed and in some cases modified to determine points of agreement (consensus), near consensus (prevailing opinion), or disagreement. RESULTS: Conference discussion added two modified questions for a total of 42 key questions for the participants. Interestingly, consensus was reached on the answers to 24 of 42 or 57% of the questions, and near consensus was reached on 14 of 42 or 33% of the questions. Only with the answers to four of 42 or 10% of the questions was there persistent controversy or disagreement. CONCLUSION: The current endoleak classification system with some important modifications is adequate. Types I and II endoleak occur after 0 to 10% and 10% to 25% of EVARs, respectively. Many (30% to 100%) type II endoleaks will seal and have no detrimental effect, which never or rarely occurs with type I endoleaks. Not all endoleaks can be visualized with any technique, and increased pressure (endotension) can be transmitted through clot. Aneurysm pulsatility after EVAR correlates poorly with endoleaks and endotension. An enlarging aneurysm after EVAR mandates surgical or interventional treatment. These and other conclusions will help to resolve controversy and aid in the management of these vexing complications and should also point the way to future research in this field.