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OBJECTIVES: The aim of this study was to present a multicentre experience of technical results and mid-term follow-up using a custom-made iliac fenestrated device (Terumo Aortic, Inchinnan, Renfrewshire, UK) for the treatment of iliac aneurysms and endoleaks. METHODS: A multicentre retrospective evaluation of 22 patients (3-12 per institution) with either an iliac artery aneurysm or endoleak treated with an iliac fenestrated device was performed. Data were gathered from 3 departments of vascular and endovascular surgery at 3 European institutions. RESULTS: Ten of the included patients (45.5%) were treated for an endoleak and 12 had aorto-iliac aneurysms (54.5%). Two patients underwent bilateral fenestrated device implantation for a total of 24 devices included in this analysis. Primary technical success was 91.7% (22 of 24 implanted devices). One of the 24 internal iliac arteries could not be cannulated and was covered (primary assisted technical success rate 95.8%) and 1 patient required a relining of the stent graft due to a mid-grade stenosis opposite the internal iliac artery fenestration. Survival at the last available follow-up (mean 15.2 ± 12.0 months, range 0.5-36.6 months) was 90.9%. CONCLUSIONS: The present investigation adds to a growing body of literature on custom-made endografts and their usefulness in achieving endovascular repair without compromising blood flow via important arterial branch vessels, such as the internal iliac artery. It presents encouraging technical and mid-term follow-up data from consecutive patients treated for iliac aneurysms or endoleaks using this custom-made device. The technique may help avoid adverse sequelae associated to a coil-and-cover approach when iliac branch devices are not feasible.
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Aneurisma de la Aorta Abdominal , Implantación de Prótesis Vascular , Procedimientos Endovasculares , Aneurisma Ilíaco , Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Aneurisma de la Aorta Abdominal/cirugía , Prótesis Vascular , Humanos , Aneurisma Ilíaco/diagnóstico por imagen , Aneurisma Ilíaco/cirugía , Diseño de Prótesis , Estudios Retrospectivos , Stents , Resultado del TratamientoRESUMEN
BACKGROUND: Surgical site infections (SSIs) of the groin remain a crucial problem in vascular surgery, prompting great interest in preventative techniques, such as closed incision negative pressure therapy (ciNPT). This prospective randomised study aimed to assess the potential benefits of ciNPT application after groin incisions for vascular surgery. METHOD: The study included 204 patients who underwent vascular surgery for peripheral artery disease (PAD) at two sites between July 2015 and May 2017. These patients received post-operative treatment with ciNPT (intervention group) or standard wound dressings (control group). After exclusion, 188 patients were assessed for SSIs using the Szilagyi classification. RESULTS: The mean patient age was 66.6 ± 9.4 years (range 43-85 years), and 70% were male (n = 132). Regarding PAD stage, 52% were stage IIB, 28% stage III, and 19% stage IV. Among the patients, 45% (n = 85) had had a previous groin incision. Bacterial swabs were performed in each case of suspected SSI (22.8% [43/188]), while 76.7% (33/188) were negative, there were 5% [5/98] positive swabs in the intervention group and 5.5% [5/90] in the control group). Antibiotics were given to 13.2% of the intervention group, and 31.1% of the control group (p = .004). The control group experienced more frequent SSIs (33.3%; 30/90) than the intervention group (13.2%; 13/98; p = .0015; absolute risk difference -20.1 per 100; 95% CI -31.9 to 8.2). This difference was based on an increased rate of Szilagyi I SSI in the control group (24.6% vs. 8.1%, p = .0012). CONCLUSION: The results confirmed a reduced superficial SSI rate after vascular surgical groin incision using ciNPT compared with standard wound dressings.
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Ingle/irrigación sanguínea , Terapia de Presión Negativa para Heridas , Enfermedad Arterial Periférica/cirugía , Infección de la Herida Quirúrgica/prevención & control , Procedimientos Quirúrgicos Vasculares , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/uso terapéutico , Femenino , Alemania , Humanos , Masculino , Persona de Mediana Edad , Terapia de Presión Negativa para Heridas/efectos adversos , Enfermedad Arterial Periférica/diagnóstico , Estudios Prospectivos , Infección de la Herida Quirúrgica/diagnóstico , Infección de la Herida Quirúrgica/microbiología , Factores de Tiempo , Resultado del Tratamiento , Procedimientos Quirúrgicos Vasculares/efectos adversosRESUMEN
Arteriovenous fistula (AVF) is the common vascular access type for a hemodialysis patient. Its failure is due to neointimal hyperplasia. Vitamin K antagonists are given to lower thrombosis tendency, but have side effects that enhance arterial calcifications. Here, we investigated the effects of vitamin K antagonists and vitamin K2 (K2) treatment on neointimal hyperplasia development and calcification in rats and in arterialized human veins. AVF was generated in female rats while chronic kidney disease (CKD) was induced using an adenine-enriched diet. Arterialization, CKD, and vitamin K antagonists all significantly enhanced venous neointimal hyperplasia. K2 treatment, additional to vitamin K antagonists, significantly reduced neointimal hyperplasia in arterialized veins in healthy rats but not in rats with CKD. Arterialization, CKD, and vitamin K antagonism all significantly increased, whereas K2 supplementation attenuated calcification in healthy rats and rats with CKD. K2 significantly enhanced matrix Gla protein carboxylation in control rats and rats with CKD. Arterialized human vein samples contained inactive matrix Gla protein at calcification and neointimal hyperplasia sites, indicating local vitamin K deficiency. Thus, vitamin K antagonists have detrimental effects on AVF remodeling, whereas K2 reduced neointimal hyperplasia and calcification indicating vasoprotective effects. Hence, K2 administration may be useful to prevent neointimal hyperplasia and calcification in arterialized veins
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Anticoagulantes/farmacología , Derivación Arteriovenosa Quirúrgica/efectos adversos , Vena Femoral/efectos de los fármacos , Neointima , Insuficiencia Renal Crónica/tratamiento farmacológico , Calcificación Vascular/prevención & control , Remodelación Vascular/efectos de los fármacos , Vitamina K 2/farmacología , Vitamina K/antagonistas & inhibidores , Anciano , Anciano de 80 o más Años , Animales , Modelos Animales de Enfermedad , Femenino , Vena Femoral/metabolismo , Vena Femoral/patología , Vena Femoral/cirugía , Humanos , Hiperplasia , Masculino , Persona de Mediana Edad , Ratas Sprague-Dawley , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/metabolismo , Insuficiencia Renal Crónica/patología , Calcificación Vascular/etiología , Calcificación Vascular/metabolismo , Calcificación Vascular/patología , Vitamina K/metabolismoRESUMEN
PURPOSE: This study was designed to evaluate CO2 computed tomography angiography (CO2-CTA) of the iliac and lower limb arteries in patients with contraindications for iodinated contrast agent (ICA). METHODS: Five patients with contraindications for ICA were examined using CO2-fluoroscopic enhanced angiography (CO2-FLA) and CO2-CTA using a high-pitch examination protocol. Objective (vessel diameter) and subjective (visual score) image quality parameters were evaluated. Pathological findings in both modalities were compared. RESULTS: CO2-CTA was feasible in all patients without adverse side effects, except for CO2 injection-associated pain. Objective vessel analysis revealed no significant difference in diameters as determined by CO2-CTA and CO2-FLA (0.44 ± 0.4 and 0.46 ± 0.41 mm, p = 0.93). CO2-CTA had on average a higher image-quality score (2.6 ± 1.0 vs. 2.3 ± 1.0, p = 0.009). While for pelvic and upper leg CO2-CTA advantageous (3.1 ± 0.74 vs. 2.7 ± 0.9, p = 0.0014) at good quality scores, for calf vessels no significant improvement was visible (1.9 ± 1.0 vs. 1.7 ± 0.9, p = 0.49) and scores were poorer. CONCLUSIONS: CO2-CTA with high-pitch CT was feasible in a limited number of patients. Image-quality scores were on average higher for CO2-CTA than for CO2-FLA, while limited imaging quality in the vessels below the knee needs further work on the CT protocol. An added value of cross-sectional imaging was apparent but needs further quantification.
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Angiografía de Substracción Digital/métodos , Dióxido de Carbono , Enfermedades Vasculares Periféricas/diagnóstico por imagen , Interpretación de Imagen Radiográfica Asistida por Computador , Tomografía Computarizada por Rayos X/métodos , Anciano , Anciano de 80 o más Años , Contraindicaciones , Medios de Contraste , Femenino , Humanos , Arteria Ilíaca/diagnóstico por imagen , Radioisótopos de Yodo , Extremidad Inferior/irrigación sanguínea , Extremidad Inferior/diagnóstico por imagen , Masculino , Enfermedades Vasculares Periféricas/fisiopatología , Proyectos Piloto , Muestreo , Sensibilidad y EspecificidadRESUMEN
Neointimal hyperplasia is one the primary causes of stenosis in arterialized veins that are of great importance in arterial coronary bypass surgery, in peripheral arterial bypass surgery as well as in arteriovenous fistulas.(1-5) The experimental procedure of vein graft interposition in the common carotid artery by using the cuff-technique has been applied in several research projects to examine the aetiology of neointimal hyperplasia and therapeutic options to address it. (6-8) The cuff prevents vessel anastomotic remodeling and induces turbulence within the graft and thereby the development of neointimal hyperplasia. Using the superior caval vein graft is an established small-animal model for venous arterialization experiment.(9-11) This current protocol refers to an established jugular vein graft interposition technique first described by Zou et al., (9) as well as others.(12-14) Nevertheless, these cited small animal protocols are complicated. To simplify the procedure and to minimize the number of experimental animals needed, a detailed operation protocol by video training is presented. This video should help the novice surgeon to learn both the cuff-technique and the vein graft interposition. Hereby, the right external jugular vein was grafted in cuff-technique in the common carotid artery of 21 female Sprague Dawley rats categorized in three equal groups that were sacrificed on day 21, 42 and 84, respectively. Notably, no donor animals were needed, because auto-transplantations were performed. The survival rate was 100 % at the time point of sacrifice. In addition, the graft patency rate was 60 % for the first 10 operated animals and 82 % for the remaining 11 animals. The blood flow at the time of sacrifice was 8±3 ml/min. In conclusion, this surgical protocol considerably simplifies, optimizes and standardizes this complicated procedure. It gives novice surgeons easy, step-by-step instruction, explaining possible pitfalls, thereby helping them to gain expertise fast and avoid useless sacrifice of experimental animals.
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Arteria Carótida Común/cirugía , Venas Yugulares/trasplante , Microcirugia/métodos , Animales , Femenino , Ratas , Ratas Sprague-DawleyRESUMEN
INTRODUCTION: As yet, murine aortic grafts have merely been monitored histopathologically. The aim of our study was to examine how these grafts can be monitored in vivo and non-invasively by using high-resolution ultrasound microimaging to evaluate function and morphology. A further aim was to prove if this in vivo monitoring can be correlated to immunohistological data that indicates graft integrity. METHODS: Murine infrarenal aortic isografts were orthotopically transplanted into 14 female mice (C57BL/6-Background) whereas a group of sham-operated animals (n = 10) served as controls. To assess the graft morphology and hemodynamics, we examined the mice over a post-operative period of 8 weeks with a sophisticated ultrasound system (Vevo 770, Visual Sonics). RESULTS: The non-invasive graft monitoring was feasible in all transplanted mice. We could demonstrate a regular post-transplant graft function and morphology, such as anterior/posterior wall displacement and wall thickness. Mild alterations of anterior wall motion dynamics could only be observed at the site of distal graft anastomosis (8 weeks after grafting (transplant vs. sham mice: 0.02 mm ± 0.01 vs. 0.03 mm ± 0.01, p<0.05). However, the integrity of the entire graft wall could be confirmed by histopathological evaluation of the grafts. CONCLUSIONS: With regard to graft patency, function and morphology, high resolution ultrasound microimaging has proven to be a valuable tool for longitudinal, non-invasive, in vivo graft monitoring in this murine aortic transplantation model. Consequently, this experimental animal model provides an excellent basis for molecular and pharmacological studies using genetically engineered mice.
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Aorta/diagnóstico por imagen , Aorta/trasplante , Ecocardiografía/métodos , Aumento de la Imagen/métodos , Almacenamiento y Recuperación de la Información/métodos , Cirugía Asistida por Computador/métodos , Animales , Femenino , Ratones , Ratones Endogámicos C57BL , Monitoreo Intraoperatorio/métodos , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
We address the coherence of the dynamics of spin-currents with components transverse to an external magnetic field for the spin-1/2 Heisenberg chain. We study current autocorrelations at finite temperatures and the real-time dynamics of currents at zero temperature. Besides a coherent Larmor oscillation, we find an additional collective oscillation at higher frequencies, emerging as a coherent many-magnon effect at low temperatures. Using numerical and analytical methods, we analyze the oscillation frequency and decay time of this coherent current-mode versus temperature and magnetic field.
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PURPOSE: To evaluate a cardiovascular magnetic resonance imaging (MRI) technique which allows the longitudinal analysis of cardiovascular remodeling in a rodent femoral arteriovenous fistula (AVF) model by means of a clinical scanner. MATERIALS AND METHODS: Eight rats underwent femoral AVF surgery and four rats served as controls. Vascular and cardiac morphology as well as cardiac function was assessed from Week 3 to 12 using contrast-enhanced, time-resolved magnetic resonance angiography (MRA) and cardiac MRI (cine gradient-echo sequence) at 3 T in one imaging session. RESULTS: Arteriovenous surgery resulted in progressive venous dilation and a subsequent cardiac adaptation. This procedure led to downstream vasodilation of the iliac vein and inferior vena cava of 179% and 188%, respectively (3 weeks). To accommodate the increased returning blood volume, cardiac output (CO) increased significantly (P=.014; 6 weeks). This was caused by increased end-diastolic volume (EDV), stroke volume (SV) and heart rate (HR) consistent with an increased volume load. A continuous increase in heart weight peaked at 12 weeks. This increase combined with a distinct end-diastolic left ventricular dilation implied eccentric hypertrophy. CONCLUSION: Small rodent MRI is feasible and clearly depicts fistula maturation and cardiac alterations. This technique proved to be a valuable tool for longitudinal in vivo monitoring in this model, which strongly resembles clinical findings in hemodialysis patients.
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Derivación Arteriovenosa Quirúrgica , Ventrículos Cardíacos/anatomía & histología , Imagen por Resonancia Magnética/métodos , Remodelación Ventricular/fisiología , Animales , Femenino , Pronóstico , Ratas , Ratas Sprague-Dawley , Resultado del TratamientoRESUMEN
PURPOSE: The aim of this study was to evaluate cardiovascular remodeling after arteriovenous fistula (AVF) surgery and to characterize the effect of chronic kidney disease (CKD) in a rodent femoral AVF model. METHODS: Sixteen rats (8 healthy; 8 CKD) underwent femoral AVF surgery; 4 animals served as controls. AVF and cardiac morphology as well as function were assessed during the fistula maturation process (until day 84 after surgery) using magnetic resonance imaging and histopathological analyses. RESULTS: Histopathological analysis revealed that a glomerular and interstitial nephropathy caused CKD. In healthy and CKD animals, AVF surgery resulted in progressive downstream vein dilation and a subsequent cardiac adaptation. This vein dilation during maturation was less in CKD rats during the early postoperative course (day 21: p=0.0475) and similar thereafter until day 84. The dilation was accompanied by an aggravation of neointimal hyperplasia (NIH) and calcification in AVFs of CKD rats. The chronic volume overload resulted in both groups in a significantly increased end-diastolic volume (healthy rats: p=0.0087; CKD rats: p=0.0333). Simultaneously, cardiac output increased 195% in healthy and 244% in uremic rats, which was caused by both a significantly increased stroke volume and heart rate. The left ventricular mass rose in AVF animals and was increased at the end of the study period, indicating a distinct cardiac hypertrophy. CONCLUSION: Our rat model showed typical cardiovascular features of the AVF maturation process, which strongly resemble clinical findings in patients. Uremia caused inferior dilation in the early phase after surgery and an exacerbation of NIH. This model should help to identify the cellular and molecular mechanisms that contribute to AVF failure.
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Derivación Arteriovenosa Quirúrgica/efectos adversos , Cardiomegalia/etiología , Arteria Femoral/cirugía , Vena Femoral/cirugía , Hemodinámica , Enfermedades Renales/terapia , Uremia/terapia , Calcificación Vascular/etiología , Adenina , Animales , Biomarcadores/sangre , Gasto Cardíaco , Cardiomegalia/sangre , Cardiomegalia/patología , Cardiomegalia/fisiopatología , Enfermedad Crónica , Dilatación Patológica , Modelos Animales de Enfermedad , Femenino , Arteria Femoral/patología , Vena Femoral/patología , Frecuencia Cardíaca , Hiperplasia , Enfermedades Renales/sangre , Enfermedades Renales/etiología , Enfermedades Renales/fisiopatología , Imagen por Resonancia Magnética , Nefrectomía , Ratas , Ratas Sprague-Dawley , Factores de Tiempo , Uremia/sangre , Uremia/etiología , Uremia/fisiopatología , Calcificación Vascular/patología , Calcificación Vascular/fisiopatologíaRESUMEN
Neointimal hyperplasia (NIH) and impaired dilatation are important contributors to arteriovenous fistula (AVF) failure. It is unclear whether chronic kidney disease (CKD) itself causes adverse remodeling in arterialized veins. Here we determined if CKD specifically triggers adverse effects on vascular remodeling and assessed whether these changes affect the function of AVFs. For this purpose, we used rats on a normal diet or on an adenine-rich diet to induce CKD and created a fistula between the right femoral artery and vein. Fistula maturation was followed noninvasively by high-resolution ultrasound (US), and groups of rats were killed on 42 and 84 days after surgery for histological and immunohistochemical analyses of the AVFs and contralateral femoral vessels. In vivo US and ex vivo morphometric analyses confirmed a significant increase in NIH in the AVFs of both groups with CKD compared to those receiving a normal diet. Furthermore, we found using histological evaluation of the fistula veins in the rats with CKD that the media shrank and their calcification increased significantly. Afferent artery dilatation was significantly impaired in CKD and the downstream fistula vein had delayed dilation after surgery. These changes were accompanied by significantly increased peak systolic velocity at the site of the anastomosis, implying stenosis. Thus, CKD triggers adverse effects on vascular remodeling in AVFs, all of which contribute to anatomical and/or functional stenosis.
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Derivación Arteriovenosa Quirúrgica , Calcinosis/etiología , Calcinosis/fisiopatología , Arteria Femoral/fisiopatología , Vena Femoral/fisiopatología , Enfermedades Renales/complicaciones , Adenina/efectos adversos , Animales , Presión Sanguínea/fisiología , Enfermedad Crónica , Constricción Patológica , Modelos Animales de Enfermedad , Femenino , Arteria Femoral/diagnóstico por imagen , Arteria Femoral/cirugía , Vena Femoral/diagnóstico por imagen , Vena Femoral/cirugía , Enfermedades Renales/inducido químicamente , Ratas , Ratas Sprague-Dawley , Flujo Sanguíneo Regional/fisiología , UltrasonografíaRESUMEN
PURPOSE: To test the feasibility of carbon dioxide (CO(2))-enhanced computed tomography (CT)-guided placement of infrarenal abdominal aortic stent-grafts in an animal model. METHODS: Appearance of a stent-graft mounted on its deployment system and the feasibility of CT fluoroscopy-guided placement were analyzed in an in vitro setting. Five domestic pigs weighing 70 to 80 kg underwent CO(2)-enhanced 64-slice CT arteriography (CTA). After surgical exposure of the right iliac artery, an 18-mm stent-graft was advanced into the abdominal aorta. Infrarenal position of the graft was monitored using CT fluoroscopy with CO(2) administered intermittently in a flow-regulated manner using a computer-controlled injection system. After the final position of the stent-graft was determined, the graft was deployed under CT fluoroscopy guidance. Graft position was confirmed by contrast enhanced 64-slice CTA and conventional catheter angiography. To quantitatively assess the position of the stent-graft, the distance between the proximal stent struts and the radiopaque marker was determined using an electronic caliper. RESULTS: CT-guided placement of infrarenal aortic stent-grafts was feasible in all animals without complications. CO(2)-enhanced CTA allowed for the identification of the renal arteries in all animals. CT fluoroscopy permitted the continuous online monitoring of stent deployment. In all animals, the grafts were placed without impairment of renal artery flow or stent-graft dislocation. The mean distance between the stent-graft and origin of the more caudal renal artery was 0.9+/-0.3 mm. CONCLUSION: CO(2)-enhanced CT fluoroscopy permits the precise placement of infrarenal aortic stent-grafts in an animal model.
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Aorta Abdominal/diagnóstico por imagen , Aorta Abdominal/cirugía , Aortografía/métodos , Implantación de Prótesis Vascular , Dióxido de Carbono , Medios de Contraste , Radiografía Intervencional/métodos , Tomografía Computarizada por Rayos X , Animales , Prótesis Vascular , Implantación de Prótesis Vascular/instrumentación , Estudios de Factibilidad , Modelos Animales , Valor Predictivo de las Pruebas , Stents , Sus scrofaRESUMEN
Accelerated intimal and medial calcification and sclerosis accompany the increased cardiovascular mortality of dialysis patients, but the pathomechanisms initiating microcalcifications of the media are largely unknown. In this study, we systematically investigated the ultrastructural properties of medial calcifications from patients with uremia. We collected iliac artery segments from 30 dialysis patients before kidney transplantation and studied them by radiography, microcomputed tomography, light microscopy, and transmission electron microscopy including electron energy loss spectrometry, energy dispersive spectroscopy, and electron diffraction. In addition, we performed synchrotron x-ray analyses and immunogold labeling to detect inhibitors of calcification. Von Kossa staining revealed calcification of 53% of the arteries. The diameter of these microcalcifications ranged from 20 to 500 nm, with a core-shell structure consisting of up to three layers (subshells). Many of the calcifications consisted of 2- to 10-nm nanocrystals and showed a hydroxyapatite and whitlockite crystalline structure and mineral phase. Immunogold labeling of calcification foci revealed the calcification inhibitors fetuin-A, osteopontin, and matrix gla protein. These observations suggest that uremic microcalcifications originate from nanocrystals, are chemically diverse, and intimately associate with proteinaceous inhibitors of calcification. Furthermore, considering the core-shell structure of the calcifications, apoptotic bodies or matrix vesicles may serve as a calcification nidus.
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Calcinosis/etiología , Calcinosis/patología , Fallo Renal Crónico/complicaciones , Túnica Media/ultraestructura , Uremia/complicaciones , Enfermedades Vasculares/etiología , Enfermedades Vasculares/patología , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVE: To test the diagnostic relevance of fast Gadobenate dimeglumine (Gd-BOPTA) enhanced, time-resolved, three-dimensional magnetic resonance angiography (t3D MRA) of distal calf and pedal vasculature in critical limb ischemia in a prospective comparison with conventional selective digital subtraction angiography (DSA) and high-resolution duplex ultrasound (US) scan. METHODS: From April 2007 to June 2008, 34 feet of 29 consecutive patients suffering from limb-threatening ischemia underwent diagnostic US scan, DSA, and t3D MRA before treatment. The investigations took place within 3 days. A t3D MRA was performed using a 3 Tesla whole-body magnetic resonance (MR) system with an eight-element phased-array coil. Image quality and diagnostic findings were subjectively analyzed by two radiologists and one vascular surgeon. Each distal calf and foot was divided into six arterial segments for DSA and t3D MRA, and four segments were investigated by US scan. Patency or occlusion was studied with all the techniques, whereby DSA and t3D MRA were additionally evaluated in patients having greater or less than 50% stenosis. Finally, images were visually assessed by the three observers by applying a six-point grading scale. The acquired data was statistically analyzed using McNemar's test and Wilcoxon's matched-pairs signed-rank sum test. The P values of less than an alpha level of .05 were considered to be statistically significant. RESULTS: We achieved MRA images of diagnostic quality in all patients. Significantly more patent pedal arteries were identified by applying t3D MRA than DSA (P < .001) and US scan (P < .02). For estimating the degree of stenosis, no technique proved to be superior (P > .28). Overall image quality was rated best for t3D MRA. Additionally, potential bypass target vessels could be clearly discriminated from pedal veins due to the temporal resolution. CONCLUSION: In our prospective study, t3D MRA has been proven to be superior to DSA and US scan in pedal vasculature imaging in critical limb ischemia. This is a valuable, noninvasive method for detecting potential pedal bypass target arteries.
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Angiografía de Substracción Digital , Arteriopatías Oclusivas/patología , Pie/irrigación sanguínea , Imagenología Tridimensional , Isquemia/patología , Angiografía por Resonancia Magnética/métodos , Ultrasonografía Doppler Dúplex , Anciano , Anciano de 80 o más Años , Arteriopatías Oclusivas/complicaciones , Arteriopatías Oclusivas/diagnóstico por imagen , Arterias/patología , Constricción Patológica , Medios de Contraste , Enfermedad Crítica , Femenino , Humanos , Aumento de la Imagen , Interpretación de Imagen Asistida por Computador , Isquemia/diagnóstico por imagen , Isquemia/etiología , Masculino , Meglumina/análogos & derivados , Persona de Mediana Edad , Compuestos Organometálicos , Valor Predictivo de las Pruebas , Estudios Prospectivos , Índice de Severidad de la Enfermedad , Factores de Tiempo , Grado de Desobstrucción VascularRESUMEN
OBJECTIVE: We assessed the surgical and neurological outcome of patients undergoing simultaneous repair of aortic arch and descending thoracic aortic aneurysms (DTAA) or thoracoabdominal aortic aneurysms (TAAA) via left thoracotomy or thoracolaparotomy. METHODS: During a 6-year period, we performed 32 procedures in 23 male and 9 female patients with DTAA or TAAA with concomitant aortic arch aneurysms. The mean age of the patients was 50.9 years (range, 18-75 years). Twenty-two patients suffered from DTAA, 4 had type-I TAAA, and 6 had type-II TAAA. The entire aortic arch was involved in 12 patients and the distal hemi-arch in 20 patients. The mean diameter of the aneurysms was 6 cm (range, 4.9-7.6 cm). All patients were operated on according to the protocol with cerebrospinal fluid drainage, distal aortic and selective organ perfusion, as well as antegrade brain perfusion. Neuromonitoring was performed by means of motor evoked potentials (MEPs), transcranial Doppler (TCD), and electroencephalography (EEG). RESULTS: All patients survived the surgical procedure and 30-day mortality did not occur. At the end of the procedure, all patients had adequate MEPs, TCD, and EEG. One patient died 47 days after operation due to gastrointestinal bleeding and therapy-resistant coagulopathy. Major postoperative complications like paraplegia or paraparesis, renal failure, and myocardial infarction were not encountered. One patient had a stroke but neurological deficits were irrelevant. Mean preoperative creatinine level was 125 mmol/L, which peaked to a mean maximal level of 130 and returned to 92 mmol/L at discharge. Other complications included bleeding requiring surgical intervention (n = 4), arrhythmia (n = 1), pneumonia (n = 5), and respiratory distress syndrome (n = 2). At a median follow-up of 38 months, all but 1 patient was alive and free of re-intervention. CONCLUSION: Single-stage repair of aortic arch and concomitant thoracic and thoracoabdominal aortic aneurysms via left-sided thoracotomy or thoraco-laparotomy yields excellent short- and midterm outcomes. Monitoring of cerebral and spinal cord function contributes to improved neurologic outcome.
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Aorta Torácica/cirugía , Aneurisma de la Aorta Torácica/cirugía , Disección Aórtica/cirugía , Isquemia Encefálica/prevención & control , Isquemia de la Médula Espinal/prevención & control , Procedimientos Quirúrgicos Vasculares/efectos adversos , Adolescente , Adulto , Anciano , Disección Aórtica/mortalidad , Disección Aórtica/patología , Aneurisma de la Aorta Torácica/mortalidad , Aneurisma de la Aorta Torácica/patología , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/etiología , Electroencefalografía , Potenciales Evocados Motores , Femenino , Humanos , Laparotomía/efectos adversos , Masculino , Persona de Mediana Edad , Monitoreo Intraoperatorio/métodos , Perfusión , Estudios Prospectivos , Isquemia de la Médula Espinal/diagnóstico , Isquemia de la Médula Espinal/etiología , Toracotomía/efectos adversos , Factores de Tiempo , Resultado del Tratamiento , Ultrasonografía Doppler Transcraneal , Procedimientos Quirúrgicos Vasculares/mortalidad , Adulto JovenRESUMEN
BACKGROUND: Neointimal hyperplasia is considered to be the major cause of arteriovenous fistula (AVF) failure, resulting in vein wall thickening, stenosis and, ultimately, occlusion. Ultrasound (US) has been shown to be effective for detecting these morphological changes in patients. The aim of this study was to develop an experimental AVF model in the rat that shows typical features of fistula maturation and allows longitudinal monitoring of fistula veins by high-resolution ultrasound. METHODS: AVFs were created by a handsewn end-to-side anastomosis between the femoral vein and the femoral artery in 15 rats. A group of sham-operated animals (n = 3) served as controls. Time-related functional and morphological AVF characteristics were assessed up to 12 weeks using ultrasound (15-MHz transducer) and were correlated to histopathological changes. RESULTS: All rats survived surgery, and the patency rate was 93%. US showed a 2-fold increase in the fistula vein diameter and mean flow velocity as well as a 4-fold increase in the intima-media thickness without significant luminal loss. The afferent femoral artery exhibited no change in intima-media thickness and only minimal adaptive increases in diameter and flow velocity. Histological evaluation confirmed these observations. CONCLUSIONS: Our AVF model in the rat demonstrates maturation effects in fistula veins similar to typical clinical findings in haemodialysis patients. Noninvasive ultrasound proved to be a valuable tool for longitudinal in vivo monitoring of the fistulas in this rodent model.
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Derivación Arteriovenosa Quirúrgica , Vena Femoral/diagnóstico por imagen , Vena Femoral/cirugía , Animales , Derivación Arteriovenosa Quirúrgica/métodos , Femenino , Modelos Animales , Ratas , Ratas Sprague-Dawley , UltrasonografíaRESUMEN
PURPOSE: To test the feasibility of carbon dioxide (CO(2))-enhanced computed tomographic (CT)-arteriography in an animal model. MATERIALS AND METHODS: Five domestic swine underwent digital subtraction angiography (DSA), conventional CT angiography with iodinated contrast material, and CO(2)-enhanced CT arteriography. For each CO(2)-enhanced DSA image series, 100 mL of pressurized CO(2) was injected at 1.3 bar. CT imaging was performed according to a standardized scan protocol (2 x 32 x 0.6 mm; 120 kV, 210 mAs(eff), 330 msec gantry rotation time). Iodinated contrast material was administered intravenously according to a biphasic injection protocol. For CO(2)-enhanced CT arteriography, CO(2) was administered intraarterially via a catheter placed in the juxtarenal aorta. An injection pressure of 0.65 bar (volume flow rate, 7.5 mL/sec) was applied. Images were assessed visually by two observers on a four-point grading scale. Absolute intraarterial attenuation values were measured. RESULTS: Image quality was rated to be the best for standard DSA. CO(2)-enhanced DSA was rated slightly superior to CO(2)-enhanced CT arteriography. No examination was considered to be nondiagnostic. The average multislice spiral CT (MSCT) scan duration was 7.9 sec +/- 0.6. The average amount of gas required for CO(2)-enhanced CT arteriography was 104 mL +/- 4, compared with 400 mL for CO(2)-enhanced DSA. Absolute attenuation values were significantly higher with CO(2)-enhanced CT arteriography (aorta, -928 HU +/- 39) than with standard CT angiography (490 HU +/- 40; P < .0001). CONCLUSIONS: CO(2)-enhanced CT arteriography is feasible. In a porcine model, this technique is capable of depicting the aortoperipheral vessels down to the lower limb. These results warrant further studies of the diagnostic value of CO(2)-enhanced MSCT arteriography for the detection of arterial pathologic processes.
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Angiografía de Substracción Digital , Angiografía/métodos , Dióxido de Carbono/administración & dosificación , Medios de Contraste , Tomografía Computarizada Espiral , Animales , Aortografía , Estudios de Factibilidad , Arteria Femoral/diagnóstico por imagen , Arteria Ilíaca/diagnóstico por imagen , Infusiones Intraarteriales , Inyecciones Intravenosas , Yohexol/administración & dosificación , Yohexol/análogos & derivados , Extremidad Inferior/irrigación sanguínea , Modelos Animales , Reproducibilidad de los Resultados , Sus scrofaRESUMEN
OBJECTIVE: The number of thoracic aortic endovascular procedures is increasing rapidly, and the clinical outcome largely depends on the underlying aortic pathology. When primary stent grafting is unsuccessful, secondary endovascular solutions are most often feasible. However, in recurrent endovascular failure without further minimally invasive options, conservative treatments or conversion to open surgery are the only remaining therapeutic strategies. METHODS: In our experience, 106 patients received thoracic aortic endovascular treatment. Five of these patients and three from other centers underwent conversion to open repair because of 4 type Ia endoleaks (3 thoracic aortic aneurysms, 1 traumatic rupture), 2 retrograde type A dissections, 1 type Ib endoleak with contained rupture, and 1 secondary false aneurysm rupture due to stent graft migration. The latter four were surgical emergencies; the other four were urgent or elective procedures. Three patients underwent supracoronary arch replacement through sternotomy. One patient had arch and proximal descending aortic replacement, three had hemiarch and descending aortic replacement, and one had descending aortic replacement through left thoracotomy. Five stent grafts were totally removed, and three endografts were left in situ. All conversions were performed according to a protocol including total extracorporeal circulation (n = 7) or left heart bypass (n = 1), cerebrospinal fluid drainage and monitoring motor-evoked potentials, transcranial Doppler, and electroencephalography. RESULTS: All patients survived the surgical procedure. Six patients had an uneventful postoperative course, whereas necrotic cholecystitis developed in one patient who required cholecystectomy and prolonged intensive care stay. One polytrauma patient died from secondary rupture due to prosthesis infection 24 days after stent graft explantation. No stroke, paraplegia, renal failure, or other major complication occurred. With a mean follow-up of 14 months (range, 4-71 months), seven patients are alive without any sign of recurrent aortic problems. CONCLUSION: Failure of thoracic endovascular aortic repair comprises a new aortic pathology. Secondary endovascular treatment is feasible in most patients; however, some patients will require open surgery to repair failures of thoracic endovascular aortic treatment. These procedures constitute a large surgical trauma and require an extensive protocol, including extracorporeal circulation, neuromonitoring, and adjunctive modalities to provide organ protection. We recommend that these procedures be performed in centers with experience and the infrastructure to offer these protective measures.
Asunto(s)
Aneurisma Falso/cirugía , Aneurisma de la Aorta Torácica/cirugía , Disección Aórtica/cirugía , Rotura de la Aorta/cirugía , Implantación de Prótesis Vascular/métodos , Adulto , Disección Aórtica/diagnóstico por imagen , Aneurisma Falso/diagnóstico por imagen , Aneurisma de la Aorta Torácica/diagnóstico por imagen , Rotura de la Aorta/diagnóstico por imagen , Aortografía/métodos , Prótesis Vascular , Implantación de Prótesis Vascular/efectos adversos , Implantación de Prótesis Vascular/instrumentación , Constricción , Remoción de Dispositivos , Circulación Extracorporea , Femenino , Estudios de Seguimiento , Alemania , Paro Cardíaco Inducido , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Mínimamente Invasivos , Países Bajos , Diseño de Prótesis , Falla de Prótesis , Reoperación , Stents , Esternón/cirugía , Toracotomía , Factores de Tiempo , Tomografía Computarizada por Rayos X , Insuficiencia del TratamientoRESUMEN
OBJECTIVE: The objective of our study was to prove the feasibility and clinical relevance of fast contrast-enhanced time-resolved 3D MR angiography (MRA) with submillimeter spatial resolution at a high magnetic field strength. SUBJECTS AND METHODS: Twenty-one patients (five women, 16 men; mean age +/- SD, 65 +/- 14 years) were examined on a 3-T whole-body MR system with an 8-element phasedarray coil for preoperative evaluation of the pedal arterial system and assessment of the visualized vessels to serve as a graft touch-down site in pedal bypass surgery. Time-resolved 3D MRA of the foot was performed after automatic injection of 0.2 mmol/kg of gadobenate dimeglumine using a sagittal gradient-echo T1-weighted sequence (TR/TE, 4.2/1.6; flip angle, 30 degrees ; field of view, 290 mm; matrix, 352; 120 slices; slice thickness, 0.8 mm) with a spatial resolution of 0.8 x 0.8 x 1.6 mm reconstructed to 0.6 x 0.6 x 0.8 mm and a temporal resolution of 3.9 seconds using keyhole and sensitivity-encoding (SENSE) technology (SENSE factors: 4 in anteroposterior direction and 2 in right-left direction). Dynamic subtractions and rotating maximum intensity projections were calculated. The original image data sets were transferred to a dedicated workstation for objective signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) analysis of the arteries. Subjective image analysis regarding image quality and diagnostic findings was performed by two radiologists in consensus. RESULTS: In all patients, images of diagnostic quality were obtained. Despite the known limitations regarding signal intensity measurements in images acquired with the use of parallel imaging technique, SNR and CNR proved to be excellent, with mean +/- SD values of 294 +/- 158 and 248 +/- 144, respectively. Although most of the patients had diabetic foot syndrome with arteriovenous shunting, the arteries and the potential vessel for bypassing could be clearly separated from the veins in each case due to the temporal information given by our study. The ability to reliably discriminate arteries from veins is of high clinical relevance in planning pedal bypass surgery. CONCLUSION: Fast contrast-enhanced time-resolved 3D MRA of the foot at 3 T is feasible and of high clinical value for the preoperative evaluation of the arterial supply of the foot.