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1.
Clin Nucl Med ; 47(7): 618-624, 2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35605055

RESUMO

BACKGROUND: Point of injection scatter (SPI) confounds breast cancer sentinel lymph node detection. Round flat lead shields (FLSs) incompletely reduce SPI, requiring repositioning. We designed lead shields that reduce SPI and acquisition time. METHODS: Two concave lead shields, a semioval lead shield (OLS) and a semispherical lead alloy shield (SLS), were created with a SICNOVA JCR 1000 3D printer to cover the point of injection (patent no. ES1219895U). Twenty breast cancer patients had anterior and anterior oblique imaging, 5 minutes and 2 hours after a single 111 MBq nanocolloid in 0.2 mL intratumoral or periareolar injection. Each acquisition was 2 minutes. Absolute and normalized background corrected scatter counts (CSCs) and scatter reduction percentage (%SR) related to the FLS were calculated. Repositionings were recorded. Differences between means of %SR (t test) and between means of CSC (analysis of variance) with Holm multiple comparison tests were determined. RESULTS: Mean %SR was 91.8% with OLS and 92% using SLS in early images (P = 0.91) and 87.2%SR in OLS and 88.5% in late images (P = 0.66). There were significant differences between CSC using FLS and OLS (P < 0.001) and between FLS and SLS (P < 0.001), but not between OLS and SLS (P = 0.17) in early images, with the same results observed in delayed studies (P < 0.001 in relation to FLS and P = 0.1 between both curved lead shields). Repositioning was required 14/20 times with FLS, 4/20 times with OLS, and 2/20 times with SLS. CONCLUSIONS: We designed 2 concave lead shields that significantly reduce the SPI and repositioning with sentinel lymph node lymphoscintigraphy.


Assuntos
Neoplasias da Mama , Neoplasias da Mama/patologia , Feminino , Humanos , Linfonodos/patologia , Metástase Linfática/patologia , Cintilografia , Compostos Radiofarmacêuticos , Biópsia de Linfonodo Sentinela/métodos
3.
Clin Nucl Med ; 46(2): 171-172, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33208617

RESUMO

ABSTRACT: A 60-year-old woman with primary hyperparathyroidism with previous nonconclusive imaging studies was referred for 18F-fluorocholine (18F-FCH) PET/CT as part of the preoperative diagnostic imaging workup to localize the adenoma before minimally invasive surgery. 18F-FCH PET/CT with dual time point was performed, acquiring immediately and 60 minutes after 18F-FCH administration. The early images demonstrated possible hyperfunctioning parathyroid tissue in the mediastinum, located in the right upper paratracheal space (region 2R), with an incidental iatrogenic subclavian venous air bubble embolism presenting as high uptake in the early images that disappeared in the late images. No symptomatology was reported during the examination.


Assuntos
Colina/análogos & derivados , Embolia Aérea/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Veias/diagnóstico por imagem , Feminino , Humanos , Pessoa de Meia-Idade
4.
Eur J Nucl Med Mol Imaging ; 48(3): 786-793, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32936372

RESUMO

PURPOSE: Spain has been one of the most affected countries by the COVID-19 pandemic, being among the countries with worse numbers, including the death rate. However, most patients are asymptomatic, although they are very contagious. The objective of this study was to investigate the incidence in oncological patients infected with SARS-CoV-2 that are asymptomatic for COVID-19 and at home and that undergo PET/CT for oncologic indications, nonrelated to COVID-19, finding in the PET/CT lung alterations that are suggestive of SARS-CoV-2 infection. METHODS: During the period of maximum incidence of the global pandemic in one of the most affected regions of Spain, there were 145 patients that met inclusion and exclusion criteria and were included in the study. Imaging findings previously described such as ground-glass opacities with low [18F]-FDG uptake were considered images suspicious for SARS-CoV-2 infection. Patients with these findings were referred to RT-PCR testing and close follow-up to confirm the presence or absence of COVID-19. RESULTS: Suspicious lung imaging findings were present in 7 of 145 patients (4.8%). Five of these 7 patients were confirmed as presenting SARS-CoV-2 infection, this is, COVID-19. In the remaining two, it was not possible to confirm the presence of COVID-19 with RT-PCR, although in one of them, PET/CT allowed an early diagnosis of a lung infection related to a bacterial pneumonic infection that was promptly and adequately treated with antibiotics. CONCLUSION: These results confirm that the prevalence of SARS-CoV-2 infection is higher than suspected and that there are asymptomatic patients that are attending imaging departments to be explored for their baseline oncologic processes. In these patients, PET/CT allows an early diagnosis of COVID-19.


Assuntos
Infecções Assintomáticas , COVID-19 , Fluordesoxiglucose F18/administração & dosagem , Neoplasias/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Feminino , Humanos , Masculino , Neoplasias/epidemiologia , Pandemias , SARS-CoV-2 , Espanha/epidemiologia
5.
Cardiovasc Intervent Radiol ; 39(2): 161-9, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26563245

RESUMO

Rationale of prostatic artery embolization (PAE) in the treatment of symptomatic benign prostatic hyperplasia is conventionally believed to include two parts: shrinkage of the enlarged prostate gland as a result of PAE-induced ischemic infarction and potential effects to relax the increased prostatic smooth muscle tone by reducing the number and density of α1-adrenergic receptor in the prostate stroma. This review describes new insights into the likely mechanisms behind PAE, such as ischemia-induced apoptosis, apoptosis enhanced by blockage of androgens circulation to the embolized prostate, secondary denervation following PAE, and potential effect of nitric oxide pathway immediately after embolization. Studies on therapeutic mechanisms in PAE may shed light on potentially new treatment strategies and development of novel techniques.


Assuntos
Embolização Terapêutica/métodos , Próstata/irrigação sanguínea , Hiperplasia Prostática/terapia , Humanos , Masculino , Próstata/patologia , Hiperplasia Prostática/patologia , Resultado do Tratamento
6.
Cardiovasc Intervent Radiol ; 39(1): 1-7, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26581418

RESUMO

Pathological features of benign prostatic hyperplasia (BPH) dictate various responses to prostatic artery embolization (PAE). Typically, BPH originates in the transition zone and periurethral region, where should be considered the primary target area in PAE procedures. Given that histological heterogeneity of components in hyperplasia nodules, epithelial or stromal, identifying the more responsive nodules to PAE will have clinical implications. Since some lower urinary tract symptoms (LUTS) in patients with BPH are usually related to bladder outlet obstruction-induced changes in bladder function rather than to outflow obstruction directly, proper selection of candidate patients prior to PAE is of great clinical importance. BPH is a typical chronic progressive condition, suggesting PAE could aim not only to relieve LUTS but also to delay or prevent the clinical progression. Awareness of the pathological background of BPH is essential for interventional radiologists to improve clinical outcomes and develop new treatment strategies in clinical practice of PAE.


Assuntos
Embolização Terapêutica , Hiperplasia Prostática/patologia , Hiperplasia Prostática/terapia , Humanos , Masculino , Próstata/patologia , Resultado do Tratamento
7.
Dig Endosc ; 25(1): 39-46, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23286255

RESUMO

AIM: The aim of the present study was to assess the safety and efficacy of CO(2) during double-balloon enteroscopy (DBE) in an experimental animal model study. In this study, insufflation with room air and with CO(2) was compared. METHODS: Twenty healthy swines were used. The animals were randomly allocated to two groups. The room air-DBE group was insufflated with room air, whereas the CO(2)-DBE group was insufflated with CO(2). Endoscopy duration was 90 min. The following parameters were measured during the study (basal, 30 min, 60 min, 90 min): invasive hemodynamic parameters, ventilatory parameters, arterial blood gases, exploration depth, as well as biochemical tests. Residual gas was evaluated at the end of DBE, at 180 min and 24 h after DBE. RESULTS: During the endoscopic exploration none of the animals showed hemodynamic, ventilatory or arterial blood gas alterations in the normal reference range for the swine species. The CO(2) group showed statistically significant differences over the room air group with lower post-procedure residual gas and greater depth of the small bowel explored. CONCLUSION: The use of CO(2) for insufflation during DBE was safe and no complications associated with CO(2) were observed. In addition, the use of CO(2) offers benefits over the use of room air for insufflation during DBE.


Assuntos
Enteroscopia de Duplo Balão , Insuflação/métodos , Análise de Variância , Animais , Dióxido de Carbono , Feminino , Hemodinâmica , Modelos Animais , Suínos
8.
Neurol Res ; 34(7): 721-4, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22889672

RESUMO

OBJECTIVES: Huntington's disease (HD) is a neurodegenerative disorder for which there is no effective treatment. Oxidative stress and inflammation are known to be involved in HD, but the precise relationship between the two remains unclear. The aim of this study was to analyze oxidative stress and inflammation biomarkers in blood of patients with HD with a view to identifying potential links between them. METHODS: Blood samples were collected from 13 patients with HD and from 10 age- and sex-matched controls, and the following were measured: C-reactive proteins, myeloperoxidase (MPO)/white blood cell (WBC) ratio, interleukin-6 (IL-6), thioredoxin reductase-1 (TrRd-1), thioredoxin-1 (Trx-1), total nitrites (NOx), nitric oxide synthase (NOS) and nitrotyrosine. RESULTS: Results showed that HD is associated to a reduction of TrRd-1 and Trx-1 levels in plasma and erythrocytes, and with an increase in the MPO/WBC ratio. A positive correlation was observed between global oxidative stress (GOS) and MPO/WBC. No changes were found in NOS and Nox levels with respect to controls. CONCLUSION: Oxidative damage may be linked to the inflammatory response in HD, via a peripheral immune response.


Assuntos
Doença de Huntington/sangue , Doença de Huntington/patologia , Mediadores da Inflamação/sangue , Estresse Oxidativo/fisiologia , Adulto , Biomarcadores/sangue , Feminino , Humanos , Doença de Huntington/fisiopatologia , Inflamação/sangue , Inflamação/diagnóstico , Inflamação/patologia , Inflamação/fisiopatologia , Masculino , Pessoa de Meia-Idade
9.
J Invasive Cardiol ; 24(5): 210-4, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22562914

RESUMO

BACKGROUND: A minimally invasive pericardial access and chronic catheterization may enhance the therapeutic effects of intrapericardial drug delivery. We aimed to evaluate the technical feasibility of percutaneous intrapericardial implantation of a drug port system for chronic local drug delivery. METHODS AND RESULTS: Under fluoroscopic guidance, a percutaneous subxiphoid access to the pericardial space was obtained with fine needle and micropuncture set in 6 Göttingen minipigs. A 6.4 Fr silicone tube and its drug port were implanted into the pericardial space and a subcutaneous pocket. One animal was euthanized immediately after procedure for acute macroscopic study. The other 5 animals were followed monthly for 2 months and then euthanized for chronic macroscopic study. Technical success was obtained in all animals. The mean procedure duration was 55.3 ± 9.6 minutes and the mean radiation exposure time was 7.9 ± 1.9 minutes. Acute macroscopic study showed no pericardial laceration at the entry site and no gross injury to the nearby epicardium. Follow-ups demonstrated that the pericardial space was intact and silicone catheters kept patent in all cases. No migration of the catheter tip out of the pericardial space or leakage of contrast was observed. All the catheters were easily removed at the end of study. Infection of the subcutaneous tunnel as a major complication was found in 1 pig. Small scattered adhesions of the pericardial space were observed in 2 pigs at chronic macroscopic study. CONCLUSIONS: Percutaneous intrapericardial catheterization for chronic local drug delivery is technically feasible and of potential for clinical trial.


Assuntos
Bombas de Infusão Implantáveis , Animais , Cateteres de Demora , Estudos de Viabilidade , Pericárdio , Suínos , Porco Miniatura
10.
AJR Am J Roentgenol ; 197(2): 495-501, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21785100

RESUMO

OBJECTIVE: The purpose of this study was to prospectively evaluate pathologic responses to transarterial prostatic embolization and its technical safety in a canine model. MATERIALS AND METHODS: Ten adult male beagle dogs were surgically castrated and given hormonal therapy for 4 months to induce prostatic hyperplasia. After three months of hormonal therapy, the dogs were randomly assigned to a transarterial prostatic embolization group (n = 7) or a control group (n = 3). Dogs in the transarterial prostatic embolization group were subjected to embolization with microspheres 300-500 µm in diameter. Four months after the study was begun, all dogs were sacrificed for pathologic study. Transrectal ultrasound and MRI were performed to evaluate pathologic responses. The data on prostate size acquired with transrectal ultrasound were processed for statistical analysis by paired Student t test. RESULTS: The canine prostatic hyperplasia model was successfully established in 10 dogs. The increase in mean prostate size being as great as 572% after 3 months of hormonal therapy. An intraprostatic cavity was detected 1 month after transarterial prostatic embolization in all seven dogs. Four dogs had significant shrinkage of the prostate, and the other three had an increase in prostate size. Imaging examinations and necropsy revealed a huge cavity occupying almost the entire prostate in the three dogs with increased prostate size. No complications associated with transarterial prostatic embolization were encountered. CONCLUSION: Transarterial prostatic embolization is a safe procedure that can induce prostatic infarction and ablate the prostate. The findings suggest the procedure has potential clinical applications in the care of patients with benign prostatic hyperplasia.


Assuntos
Embolização Terapêutica/métodos , Hiperplasia Prostática/terapia , Angiografia , Animais , Modelos Animais de Doenças , Cães , Imageamento por Ressonância Magnética , Masculino , Microesferas , Estudos Prospectivos , Hiperplasia Prostática/diagnóstico por imagem , Hiperplasia Prostática/patologia , Distribuição Aleatória , Segurança , Ultrassonografia
11.
Front Neurosci ; 5: 84, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21779233

RESUMO

UNLABELLED: Most work on visual prostheses has centered on developing retinal or cortical devices. However, when retinal implants are not feasible, neuroprostheses could be implanted in the lateral geniculate nucleus (LGN) of the thalamus, the intermediate relay station of visual information from the retina to the visual cortex (V1). The objective of the present study was to determine the types of artificial stimuli that when delivered to the visual thalamus can generate reliable responses of the cortical neurons similar to those obtained when the eye perceives a visual image. Visual stimuli {S(i)} were presented to one eye of an experimental animal and both, the thalamic {RTh(i)} and cortical responses {RV1(i)} to such stimuli were recorded. Electrical patterns {RTh(i)*} resembling {RTh(i)} were then injected into the visual thalamus to obtain cortical responses {RV1(i)*} similar to {RV1(i)}. Visually- and electrically generated V1 responses were compared. RESULTS: During the course of this work we: (i) characterized the response of V1 neurons to visual stimuli according to response magnitude, duration, spiking rate, and the distribution of interspike intervals; (ii) experimentally tested the dependence of V1 responses on stimulation parameters such as intensity, frequency, duration, etc., and determined the ranges of these parameters generating the desired cortical activity; (iii) identified similarities between responses of V1 useful to compare the naturally and artificially generated neuronal activity of V1; and (iv) by modifying the stimulation parameters, we generated artificial V1 responses similar to those elicited by visual stimuli. Generation of predictable and consistent phosphenes by means of artificial stimulation of the LGN is important for the feasibility of visual prostheses. Here we proved that electrical stimuli to the LGN can generate V1 neural responses that resemble those elicited by natural visual stimuli.

12.
J Urol ; 185(5): 1939-45, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21421242

RESUMO

PURPOSE: We assessed the therapeutic value of a new treatment option for ureteral strictures that may avoid urothelial hyperplasia, which is the main cause of metallic stent failure. MATERIALS AND METHODS: We used 24 pigs in this study. An experimental model of ureteral stricture was induced in all animals. Obstruction was confirmed by ultrasound and retrograde ureteropyelogram 6 weeks after model creation. The pigs were then randomly allocated to 2 experimental groups. Therapy involved placement of a 6 × 30 mm metallic ureteral covered stent in the ureteral stricture in group 1 and subsequent endoureterotomy at the ureteral segments adjacent to the 2 ends of the stent in group 2. A double pigtail stent was then deployed for 3 weeks. Completion studies 6 months after therapy included retrograde ureteropyelogram, endoluminal ultrasound and ureteroscopy to assess urothelial hyperplasia formation. RESULTS: At the end of the study evidence of urothelial hyperplasia was seen in 50% of the pigs in group 1 and in 29% in group 2. Four and 2 cases of cranial stent migration in groups 1 and 2, respectively, were seen at 6 months. Hyperplasia and renal involvement were statistically significantly different between the groups with more damage in group 1 than in group 2. CONCLUSIONS: Hyperplasia was markedly reduced when ureteral peristalsis was inhibited by endoureterotomy at the area of interaction between the stent and the ureter.


Assuntos
Stents , Obstrução Ureteral/prevenção & controle , Análise de Variância , Animais , Modelos Animais de Doenças , Feminino , Fluoroscopia , Hiperplasia/diagnóstico por imagem , Hiperplasia/prevenção & controle , Metais , Distribuição Aleatória , Estatísticas não Paramétricas , Sus scrofa , Ultrassonografia , Obstrução Ureteral/diagnóstico por imagem , Ureteroscopia
13.
Urol Int ; 85(3): 314-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20389053

RESUMO

OBJECTIVES: The aim of this experimental study was to assess the possibility of decreasing the size of the ureteral stents used after an endopyelotomy. To this end, an experimental study was performed which compared a ureteral double-J wire stent versus a standard 7F ureteral stent after endopyelotomy. METHODS: Twenty healthy female pigs were randomly divided into 2 groups: group I (double pigtail ureteral stent 7F) and group II (lumenless ureteral double-J wire stent, Zebrastent™, 0.035 inches in diameter). Percutaneous, endoluminal ultrasonographic and fluoroscopic studies were analyzed during the 3 different phases of the study. The first phase included premodel documentation of normal urinary tracts and laparoscopic ureteropelvic junction (UPJ) obstruction induction. During the second phase, 6 weeks later, diagnosis and endopyelotomy were carried out. Sixteen weeks after the obstruction treatment, follow-up imaging studies and postmortem evaluations of all animals were performed. RESULTS: After the sonographic and fluoroscopic assessments, we determined the success rate for each group: 80% for group I and 90% for group II. No significant statistical differences were evident in the evolution of the diameter of the UPJ between groups. Better healing of the UPJ and a lower level of retroperitoneal repercussions were seen in group II. CONCLUSIONS: The ureteral double-J wire stent (Zebrastent) has been shown to be highly effective after endopyelotomy. This means that it is possible to reduce the size of ureteral stents after endopyelotomy with the advantages that this entails. Double-J ureteral stents probably act as a scaffold rather than a mold.


Assuntos
Laparoscopia/métodos , Stents , Ureter/cirurgia , Procedimentos Cirúrgicos Urológicos/instrumentação , Procedimentos Cirúrgicos Urológicos/métodos , Urologia/métodos , Animais , Modelos Animais de Doenças , Feminino , Fluoroscopia/métodos , Pelve Renal/patologia , Suínos , Resultado do Tratamento , Ultrassonografia/métodos , Sistema Urinário/patologia , Urografia/métodos
14.
Urology ; 73(3): 649-52; discussion 652-4, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19100601

RESUMO

OBJECTIVES: To present, in an experimental study, an assessment of innovative digital fluoroscopy systems with three-dimensional (3D) reconstruction for use in endourologic applications. METHODS: The experiment was performed in a pig model. We used 5 pigs. An obstructive uropathy model was created in the right kidney to dilate the urinary tract for group 1. Group 2 consisted of the nondilated left kidney. After selecting the tract on the 3D image, the lower caliceal group was punctured in the 2 kidneys under fluoroscopic control, to assess the efficiency of the 3D reconstruction when selecting the renal calix to be punctured. RESULTS: The 3D reconstruction system allowed us to obtain reconstruct the pelvis in three dimensions, isolated as the pelvis and renal parenchyma, as well as the adjacent bony relationships. In this study, the success rate was 100% for locating the selected renal calix. CONCLUSIONS: With this 3D reconstruction system, we were able to obtain a series of images that allowed for the study of the volume of the kidney, perfectly determining its renal calix distribution in the operating room. This enabled us to determine the precise delineation of the target calix. We, therefore, consider this new urologic application of fluoroscopy very useful in surgical planning for antegrade access of the upper urinary tract.


Assuntos
Fluoroscopia/métodos , Imageamento Tridimensional , Nefrostomia Percutânea/métodos , Animais , Feminino , Modelos Animais , Suínos
15.
Radiology ; 246(3): 783-9, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18223124

RESUMO

PURPOSE: To prospectively evaluate the technical feasibility and safety of transcatheter arterial embolization (TAE) of the prostate in healthy pigs. MATERIALS AND METHODS: The study was approved by the institutional ethics committee for animal research. Sixteen large white male pigs were randomly assigned to the embolization group (n = 8) or control group (n = 8). Selective angiography was performed in all animals after general anesthesia was induced. In the embolization group, microspheres 500-700 microm in diameter were used to occlude the prostatic branches. Three months later, the animals' sexual function while breeding with female pigs was subjectively evaluated by using a three-point scale. At necropsy, the prostates were removed for size measurement and histopathologic examination. Paired Student t and Wilcoxon rank sum tests were used for statistical analysis. RESULTS: TAE was technically successful in all animals, without associated complications. The mean prostate volume after embolization was significantly (P < .001) reduced compared with the mean prostate volume for the group control. No significant difference (P = .328) in sexual function was noted between the two groups. Histologic examination revealed that the microspheres had occluded the arterioles of the prostate, with disappearance of the nearby partially normal gland structure and atrophy of the residual gland tissue. CONCLUSION: TAE of the prostate can induce shrinkage of the prostate without compromising the sexual desire and erectile function of animals. This finding suggests that TAE has potential as an alternative treatment for symptomatic benign prostatic hyperplasia in humans.


Assuntos
Embolização Terapêutica/métodos , Hiperplasia Prostática/terapia , Angiografia , Animais , Cateterismo/métodos , Modelos Animais de Doenças , Estudos de Viabilidade , Masculino , Estudos Prospectivos , Distribuição Aleatória , Comportamento Sexual Animal , Estatísticas não Paramétricas , Suínos
16.
Neuromodulation ; 10(1): 52-8, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22151812

RESUMO

Objectives. This study was designed to assess vagus nerve stimulation effects on the food intake pattern in swine and determine the electrical stimulus direction. Material and Methods. Fifteen Large White pigs were randomly divided into three groups, groups A-C. All animals underwent implantation of a vagus nerve stimulator at the gastro-esophogeal junction. In group A, the stimulation was switched off, whereas stimulation was switched on in groups B and C. Food intake and body weight were registered in groups A and B, but not in group C, which was used to measure direction of stimulation in the vagus and effect on heart rate and blood pressure. Variables measured in group C included the bispectral index, blood pressure, and heart rate. A Student's t-test and one-way analysis of variance were used to detect differences between groups. All animals were sacrificed to identify effects of implantation and stimulation on the vagus nerve. Results. With respect to food intake, there was no difference between groups A and B; however, body weight did register a continuous increase. During stimulation, in group C arterial pressures decreased significantly, whereas the heart rate and bispectral index increased. Conclusion. The stimulation protocol applied in this study was insufficient to cause changes in the feeding behavior of swine; however, it did increase central nervous system activity.

17.
Radiology ; 238(2): 719-24, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16371586

RESUMO

This study was performed with approval from the ethics committee for animal research of the local government. The purpose of the study was to evaluate the technical feasibility of a technique for subxiphoid access to the normal pericardial space with a micropuncture set in 10 large white pigs. With fluoroscopic guidance, a fine needle was inserted through a subxiphoid approach into the anterior mediastinal space to puncture the pericardium, and a micropuncture set was placed in the pericardial space successfully in all animals without complications. Necropsy at 24 hours did not reveal hemomediastinum, hemopericardium, or laceration of the pericardium. Results of the experiments in animals indicated that the technique was feasible and safe.


Assuntos
Pericárdio , Punções/métodos , Animais , Estudos de Viabilidade , Feminino , Masculino , Suínos , Processo Xifoide
18.
Cardiovasc Intervent Radiol ; 28(6): 773-8, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-16059765

RESUMO

The aim of the study was to determine the optimal stent size and stenting duration following retrograde endoureterotomy of experimental ureteral strictures. Twenty healthy Large White female pigs were randomly divided into four groups, depending on stent size (7F vs 14F) and stenting duration (3 weeks vs 6 weeks). Three additional pigs were used as the control group. The internal ureteral diameter was measured 2 cm below the lower pole of the right kidney. Histopathological changes of the urinary tract, ultrasonographic and fluoroscopic studies, urine culture, and serum urea and creatine levels were analyzed during the different phases of the study. The study was divided into three phases. Phase I included premodel documentation of the normal urinary tract and laparoscopic ureteral stricture creation. During the second phase 1 month later, the diagnosis and endourologic treatment of strictures were performed. Phase III began 4 weeks after stent removal; follow-up imaging studies and postmortem evaluation of all animals were performed. Ureteral strictures developed in all animals 4 weeks after model creation. Results from ureteral diameter measurements and pathological studies revealed no statistically significant intergroup differences. However, prevalence of urinary infection proved to be directly related to stent size (14F) and permanence (6 weeks). The chi square results suggest a statistically significant relationship between the urinary tract infection and recurrent strictures (alpha = 0.046). We recommend the use of 7F stents for a period of 3 weeks or less, as these are more easily positioned and result in the reduction of secondary side effects (lower infection rate, less intramural ureteral lesions). A significant relationship between urinary tract infection and stricture recurrence was found in this experimental study.


Assuntos
Constrição Patológica/cirurgia , Stents , Ureter/cirurgia , Doenças Ureterais/cirurgia , Ureteroscopia , Animais , Constrição Patológica/complicações , Constrição Patológica/diagnóstico , Modelos Animais de Doenças , Feminino , Seguimentos , Recidiva , Stents/efeitos adversos , Suínos , Fatores de Tempo , Resultado do Tratamento , Ultrassonografia , Ureter/diagnóstico por imagem , Ureteroscopia/efeitos adversos , Ureteroscopia/métodos , Infecções Urinárias/etiologia
19.
J Vasc Interv Radiol ; 16(4): 521-9, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15802452

RESUMO

PURPOSE: To determine if the deployment of metallic ureteral stents in benign ureteral stricture is more effective than endoureterotomy. MATERIALS AND METHODS: Twenty pigs were randomly divided in two groups to be treated with endoureterotomy or metallic stents. The internal ureteral diameter 2 cm distal to the ureteropelvic junction, histopathologic changes, ultrasonographic and fluoroscopic studies, urine culture, and serum urea and creatinine levels were analyzed during the phases of the study. The study was divided into three phases. The first included premodel documentation of normal urinary tract and laparoscopic ureteral stricture induction. In the second phase 1 month later, diagnosis and endoureteral treatment were carried out. Twelve weeks after stricture treatment, follow-up imaging studies and postmortem evaluation of all animals were performed. RESULTS: The success rates were 80% for endoureterotomy and 70% for metallic stent implantation. In all animals in the latter group, a ureteral hyperplasic reaction took place that affected the zone of stent implantation. One difference between the groups was the presence of urinary infection in 30% of animals in the endoureterotomy group and in no animals treated with metallic stents. Statistically significant differences in ureteral diameter between the first and second study phases were found within both groups (P < .0001), but not between groups (P = .021). Results from pathologic analysis revealed statistically significant differences between groups (P = .0029). CONCLUSIONS: The interaction among the distal end of the metallic stent, the urothelium, and peristalsis might be the origin of the failure of these devices. Although the deployment of metallic stents is attractive compared with other endourologic techniques like endoureterotomy in cases of benign strictures, certain problems must be resolved to prevent hyperplasia. Until then, this technique will not be a fully reliable therapeutic option for ureteral disorders.


Assuntos
Cateterismo , Stents , Ureter/patologia , Doenças Ureterais/terapia , Animais , Bacteriúria/microbiologia , Cateterismo/efeitos adversos , Constrição Patológica/patologia , Constrição Patológica/terapia , Creatinina/sangue , Modelos Animais de Doenças , Feminino , Fibrose , Hiperplasia , Distribuição Aleatória , Membrana Serosa/patologia , Stents/efeitos adversos , Suínos , Fatores de Tempo , Resultado do Tratamento , Ureia/sangue , Doenças Ureterais/patologia , Infecções Urinárias/etiologia , Urotélio/patologia
20.
Res Vet Sci ; 76(1): 69-75, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14659732

RESUMO

The objective of this study is to evaluate the dilation of the ureter using endoureterotomy and an expanding-sheath double pigtail ureteral stent in the treatment of experimentally induced ureteral strictures in the porcine animal model. This is a new treatment in the ureteral strictures resolution in Veterinary Urology, although it is not a common affection, it usually appears as a consequence of ureteritis and in the iatrogenic female genital surgery. The experimental study is design in three phases: induction of experimental stricture, diagnosis and treatment of the stricture and follow-up. We have used 10 healthy Large White female pigs. The internal ureteral diameter was measured prior to laparoscopic ligature stricture induction using retrograde ureteropyelography (RUPG). Experimental stricture was diagnosed 4 weeks after intervention, using RUPG and ultrasound, and treated by endoureterotomy and subsequent placement of a double pigtail ureteral stent, which was removed 6 weeks later. The study finished 4 weeks later with measurement of ureteral diameters using RPUG and ultrasound evaluation. Except in one case, all ureters displayed permanent dilation of the strictured area for 10 weeks after treatment (6 weeks with ureteral stent and 4 more weeks without stent). Finally, this technique proved to be effective in cases of short-length and short-living ureteral strictures, and represents a viable alternative to conventional surgery in animals.


Assuntos
Stents , Ureter/cirurgia , Obstrução Ureteral/cirurgia , Animais , Modelos Animais de Doenças , Desenho de Prótese , Suínos
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