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1.
Chirurgie (Heidelb) ; 95(5): 359-366, 2024 May.
Artigo em Alemão | MEDLINE | ID: mdl-38329518

RESUMO

Open revascularization for mesenteric ischemia has retained a significant value despite the increasing importance and use of endovascular techniques. Surgical procedures such as retrograde embolectomy, thromboendarterectomy and visceral bypass are indispensable components of the therapeutic armamentarium, particularly in cases of multisegmental vascular involvement, failure of previous endovascular treatment and concomitant presence of peritonitis, shock or multiorgan failure. In this context, preoperative multiphase computed tomography (CT) angiography is essential for the planning and outcome of visceral revascularization. This article summarizes the indications, technique, and results of the most important open surgical procedures.


Assuntos
Procedimentos Endovasculares , Isquemia Mesentérica , Humanos , Isquemia Mesentérica/diagnóstico por imagem , Isquemia Mesentérica/cirurgia , Resultado do Tratamento , Procedimentos Endovasculares/métodos , Embolectomia , Artérias
2.
Chirurgie (Heidelb) ; 94(8): 714-718, 2023 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-37115224

RESUMO

BACKGROUND: The long-term application of tunneled central venous catheters leads to the development of firm adhesions between the wall of the vein and the catheter, which makes removal of the catheter difficult or impossible. The treatment options in such cases include abandonment of catheter parts or an open surgical approach up to sternotomy. At present, procedural alternatives are available, which include endovascular techniques such as the use of laser energy and endoluminal dilatation. METHODS: This article describes the successful application of endoluminal dilatation for removal of ingrown central venous catheters in three patients, which had impacted in the superior vena cava and brachiocephalic vein. A 5 Fr (Cordis, Santa Clara, CA, USA) sheath was inserted into one lumen through the severed end of the double lumen catheter. Subsequently, a balloon catheter was inserted into the other lumen to prevent retrograde bleeding or air embolism. Under fluoroscopy a guidewire (0.018, Terumo Medical Corporation, Somerset, New Jersey, USA) was introduced via the sheath to beyond the tip of the hemodialysis catheter into the right atrium. Finally, an angioplasty balloon was inserted (4â€¯× 80 mm) via the guidewire and the complete catheter was sequentially inflated with a pressure of 4 atm. It was then possible to pull out the catheter with no difficulty. RESULTS: This technique resulted in the removal of the central venous catheters in all three patients, without any relevant complications or resistance. CONCLUSION: By dissolving adhesions between the catheter and the vein wall, endoluminal balloon dilatation constitutes a reliable and safe technique for the extraction of impacted central venous hemodialysis catheters and may thus help to avoid further invasive surgical procedures.


Assuntos
Cateterismo Venoso Central , Cateteres Venosos Centrais , Humanos , Cateteres Venosos Centrais/efeitos adversos , Cateterismo Venoso Central/efeitos adversos , Cateteres de Demora/efeitos adversos , Veia Cava Superior , Dilatação , Resultado do Tratamento , Remoção de Dispositivo/métodos
3.
Zentralbl Chir ; 142(1): 46-53, 2017 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-27672739

RESUMO

Introduction: Practical clinical expertise is a crucial part of medical professionalism. Several studies have shown that medical students are poorly trained in practical skills during their undergraduate training. Even the students rated their own expertise in practical skills as poor. The amendments to the German Regulating Licenses in Practical Medicine are intended to strengthen practical clinical training. The aim of the present study is to use focus groups to analyse practical clinical training with respect to organisation, difficulties and problems from the learners' perspective. Methods: The present qualitative study uses the focus group approach. Each focus group was composed of a maximum of 6 students per group with the same level of training. Using a standardised interview manual, a total of 31 students and four first-year residents participated in the study. Data interpretation was performed using structured qualitative content analysis. Results: The present work demonstrates that students of all levels of training greatly value their training in practical clinical expertise, especially in clinical skills. Due to the lack of defined learning objectives for practical skills, students training in clinical internships and medical registrar positions are highly dependent on the motivation and interest of the individual clinical teacher and the learner himself. Students struggle to estimate their actual level of expertise due to the lack of defined learning objectives. This is exacerbated by the fact that students rarely receive feedback about their expertise. Students complain that many teachers do not know the level of training required of their students. Conclusion: The definition of basic and specific learning objectives and the communication of this between learners and teachers is an essential part of practical clinical training.


Assuntos
Atitude do Pessoal de Saúde , Cirurgia Geral/educação , Preceptoria , Estudantes de Medicina/psicologia , Ensino , Adulto , Competência Clínica/normas , Currículo/normas , Feminino , Grupos Focais , Humanos , Masculino , Pessoa de Meia-Idade , Assistentes Médicos/educação , Assistentes Médicos/psicologia , Assistentes Médicos/normas , Preceptoria/normas , Pesquisa Qualitativa
5.
Chirurg ; 84(10): 869-74, 2013 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-24018916

RESUMO

BACKGROUND: For competency-oriented teaching in surgery a comprehensive medical educational training and professionalization of clinical teachers is essential. The Surgical Working Group for Teaching has therefore set itself the task of developing an appropriate training concept. METHOD: In the first step the core group took stock of the most relevant educational barriers in the clinical environment. Taking into account these findings a trimodular course was devised that addressed both previous knowledge and different clinical functions of the faculty as well as modern concepts of competency-based academic teaching. RESULTS: The A course is designed for medical teaching of novices with a focus on collation of the medical history, clinical examination and teaching of practical skills. The B course is devised for experienced clinicians and should qualify them for competency-based teaching in complex educational scenarios, such as the operating room or ward rounds, while the C course is directed to a group of persons entrusted with the organization and administration of clinical teaching.


Assuntos
Educação Baseada em Competências/organização & administração , Currículo , Cirurgia Geral/educação , Modelos Educacionais , Sociedades Médicas , Competência Clínica , Educação Baseada em Competências/métodos , Docentes de Medicina , Alemanha , Humanos
7.
Chirurg ; 84(4): 277-85, 2013 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-23494054

RESUMO

Competency-based medical education is a prerequisite to prepare students for the medical profession. A mandatory professional qualification framework is a milestone towards this aim. The National Competency-based Catalogue of Learning Objectives for Undergraduate Medical Education (NKLM) of the German Medical Faculty Association (MFT) and the German Medical Association will constitute a basis for a core curriculum of undergraduate medical training. The Surgical Working Group on Medical Education (CAL) of the German Association of Surgeons (DGCH) aims at formulating a competency-based catalogue of learning objectives for surgical undergraduate training to bridge the gap between the NKLM and the learning objectives of individual medical faculties. This is intended to enhance the prominence and visibility of the surgical discipline in the context of medical education. On the basis of different faculty catalogues of learning objectives, the catalogue of learning objectives of the German Association of Orthopedics and Orthopedic Surgery and the Swiss Catalogue of Learning Objectives representatives of all German Surgical Associations cooperated towards a structured selection process of learning objectives and the definition of levels and areas of competencies. After completion the catalogue of learning objectives will be available online on the webpage of the DGCH.


Assuntos
Competência Clínica/normas , Educação Baseada em Competências/normas , Educação de Graduação em Medicina/normas , Cirurgia Geral/educação , Catálogos como Assunto , Currículo/normas , Docentes de Medicina , Alemanha , Humanos , Ortopedia/educação , Sociedades Médicas
8.
Eur J Vasc Endovasc Surg ; 38(4): 456-62, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19564122

RESUMO

OBJECTIVES: This study aims to evaluate the feasibility of external polyester scaffolding in infrainguinal bypass grafting when available vein material is suboptimal due to varicosity or dilatation. Primary objectives were short-term primary patency, assisted primary patency and secondary patency. Secondary objectives were to assess the rate of graft stenoses, infections and other adverse effects related to the use of external scaffolding. MATERIALS AND METHODS: A total of 50 consecutive patients were included in this prospective, multicentre, feasibility study from six centres. The indication for infrainguinal bypass was critical limb ischaemia (64%), severe claudication (34%) or popliteal aneurysm (2%). Indications for the use of the external scaffolding were varicosity of the vein graft, ectatic vein graft or the use of spliced vein grafts with segments of widely differing diameters. Duplex scanning of the graft was done perioperatively and at follow-up visits at 1, 3, 6 and 12 months after operation. RESULTS: Primary patency, assisted primary patency and secondary patency at 6 months were 82.3% (+/-SE 6.2%), 88.6% (+/-SE 4.8%) and 92.1% (+/-SE 4.4%), respectively. Six graft stenoses were detected in duplex surveillance. There were no infections related to polyester mesh. CONCLUSIONS: External scaffolding of infrainguinal vein grafts may be a promising innovation. Early results from this multicentre study show that polyester mesh is safe and feasible adjunct to peripheral revascularization enabling the use of otherwise non-optimal vein grafts with acceptable short-term patency.


Assuntos
Extremidade Inferior/irrigação sanguínea , Doenças Vasculares Periféricas/cirurgia , Poliésteres , Telas Cirúrgicas , Procedimentos Cirúrgicos Vasculares/instrumentação , Veias/transplante , Adulto , Idoso , Idoso de 80 Anos ou mais , Aneurisma/cirurgia , Desenho de Equipamento , Estudos de Viabilidade , Feminino , Oclusão de Enxerto Vascular/etiologia , Oclusão de Enxerto Vascular/cirurgia , Humanos , Claudicação Intermitente/etiologia , Claudicação Intermitente/cirurgia , Isquemia/etiologia , Isquemia/cirurgia , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Doenças Vasculares Periféricas/complicações , Doenças Vasculares Periféricas/diagnóstico , Doenças Vasculares Periféricas/fisiopatologia , Flebografia , Projetos Piloto , Artéria Poplítea/cirurgia , Estudos Prospectivos , Reoperação , Infecção da Ferida Cirúrgica/etiologia , Infecção da Ferida Cirúrgica/cirurgia , Fatores de Tempo , Resultado do Tratamento , Ultrassonografia Doppler Dupla , Grau de Desobstrução Vascular , Procedimentos Cirúrgicos Vasculares/efeitos adversos , Veias/patologia
9.
Hamostaseologie ; 24(3): 151-6, 2004 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-15314698

RESUMO

A screening program for infrarenal abdominal aortic aneurysm (AAA) has limited cost-effectiveness. Yet, screening of the subpopulation of smoking men aged 60-75 years, or men and smoking women with a family history of vascular diseases or other cardio-vascular co-morbidity is cost-effective and has been demonstrated. It is suited to halve the increasing mortality of AAA. Elective repair of AAA is justified at diameters larger than 5.5 cm for men, but uncertain for women. However, aortic diameters between 4.5 and 5 cm in women probably necessitate an invasive approach. Surveillance of patients who still not meet these criteria should not only include the absolute diameter of the aneurysm, but direct individuals with aneurysms at an annual expansion rate of more than 0.5 cm to elective repair.


Assuntos
Aneurisma da Aorta Abdominal/epidemiologia , Animais , Aneurisma da Aorta Abdominal/diagnóstico , Aneurisma da Aorta Abdominal/mortalidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Caracteres Sexuais , Fumar
10.
Eur J Vasc Endovasc Surg ; 24(2): 166-75, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12389241

RESUMO

OBJECTIVE: Accelerated re-endothelialisation may inhibit the development of restenosis. Basic Fibroblast Growth Factor (bFGF) plays a key role for early proliferative activity in the artery following injury. Therefore, this study was devised to examine the effect of photodynamic therapy (PDT) on post-injury re-endothelialisation in vivo, and bFGF-mRNA expression in endothelial cells (EC) in vitro. MATERIALS AND METHODS: Rat carotid arteries were balloon-injured prior to PDT. Arteries were analysed after 1, 3, 5, 14 and 30 days. Morphometric measurements were undertaken following injection of 0.5% Evans Blue which stains non-endothelialised surfaces only. To identify EC, immunohistochemistry (CD-31) was performed. Proliferation was assessed by fluorescence cell counting. PCR quantification of bFGF-mRNA expression and proliferation were assessed in bovine aortic EC which were plated on isolated, PDT-treated EC-derived extracellular matrix at (12), 24, 48 (72 h). RESULTS: Three days following PDT, arteries displayed significantly increased endothelial lining (p = 0.02), which was more pronounced at 5 (p = 0.03) and 14 days (p = 0.02). At 30 days no relevant differences between PDT and control were noted. EC proliferation on PDT-treated matrix was significantly increased at 24, 48, and 72 h (p = 0.0004), whereas bFGF-mRNA expression was significantly increased at 24 h only (p = 0.007). CONCLUSION: Post-injury PDT appears to accelerate re-endothelialisation. Expression of bFGF-mRNA, however, although increased shortly after PDT, may not be responsible for a constant stimulation of EC proliferation.


Assuntos
Reestenose Coronária/prevenção & controle , Reestenose Coronária/fisiopatologia , Endotélio Vascular/lesões , Endotélio Vascular/efeitos da radiação , Fator 2 de Crescimento de Fibroblastos/farmacologia , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/efeitos da radiação , Fotoquimioterapia , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/efeitos da radiação , Cicatrização/efeitos dos fármacos , Cicatrização/efeitos da radiação , Animais , Artérias Carótidas/efeitos dos fármacos , Artérias Carótidas/fisiopatologia , Artérias Carótidas/efeitos da radiação , Lesões das Artérias Carótidas/fisiopatologia , Lesões das Artérias Carótidas/terapia , Reestenose Coronária/genética , Modelos Animais de Doenças , Endotélio Vascular/fisiopatologia , Fator 2 de Crescimento de Fibroblastos/genética , Expressão Gênica/genética , Técnicas In Vitro , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , Cicatrização/fisiologia
11.
J Vasc Surg ; 31(6): 1168-77, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10842154

RESUMO

PURPOSE: Photodynamic therapy (PDT), the light activation of photosensitizers to produce free radicals, is known to inhibit experimental intimal hyperplasia (IH). However, its clinical application has been limited by the lack of a suitable approach and a clinically appropriate photosensitizer. The aim of this study was to determine the effectiveness of a clinical approach for PDT, while testing its ability to favorably modulate the vascular wound healing response. METHODS: Rat carotid arteries were balloon-injured (BI), and for PDT, the arteries were irradiated with thermoneutral laser light (lambda = 660 nm, 100 J/cm(2)) after the photosensitizer methylene blue (MB) was delivered locally. Control rats included BI alone and MB after BI alone. Arteries were analyzed after 2 weeks with morphometric evaluation (n = 6) and in situ hybridization for versican and procollagen type I gene expression (digitized image pixel analyses, n = 3). RESULTS: No IH developed in PDT-treated arteries (0 +/- 0 mm(2); compared with BI, 0.192 +/- 0.006 mm(2); P <.0001). The diameters remained unchanged (PDT, 0.95 +/- 0.04 mm; BI, 0.94 +/- 0.05 mm; uninjured artery, 0.91 +/- 0.06 mm). Arterial injury resulted in an increase of versican and procollagen type I messenger RNA (mRNA) in the adventitia and neointima. In the repopulating cells of the adventitia after PDT, there was a significant decrease in versican mRNA (% of positive pixels per high-power field: PDT, 1.13% +/- 0.39%; BI, 2.93% +/- 0.61%; P <.02), but not in procollagen type I mRNA. CONCLUSION: The decrease of versican mRNA expression of repopulating cells after PDT reflects favorable healing on a molecular level. Site-specific delivery of MB, a clinically appropriate photosensitizer, followed by PDT represents a suitable method to promote favorable healing after balloon intervention and further supports its role for inhibiting postinterventional restenosis.


Assuntos
Artérias Carótidas/efeitos dos fármacos , Cateterismo/efeitos adversos , Azul de Metileno/uso terapêutico , Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Análise de Variância , Animais , Artérias Carótidas/patologia , Proteoglicanas de Sulfatos de Condroitina/genética , Tecido Elástico/efeitos dos fármacos , Tecido Elástico/patologia , Regulação da Expressão Gênica , Hiperplasia , Processamento de Imagem Assistida por Computador , Hibridização In Situ , Lasers , Lectinas/genética , Lectinas Tipo C , Masculino , Pró-Colágeno/genética , Proteoglicanas/genética , RNA Mensageiro/genética , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Túnica Íntima/efeitos dos fármacos , Túnica Íntima/patologia , Versicanas , Cicatrização
12.
Photochem Photobiol ; 70(4): 663-8, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10546562

RESUMO

With conflicting results in the literature on the ability of photodynamic therapy (PDT) to inhibit intimal hyperplasia (IH), the present study systematically investigated the effects of drug and light dosimetry on the biologic responses in the artery wall. The rat common carotid artery was balloon-injured and pressurized with benzoporphyrin-derivative monoacid ring (BPD). Then, PDT was performed with an external laser at different fluences and the biologic responses of the artery wall were histologically examined at 24 h and at 2 weeks. Photodynamic therapy effects on injured arteries can be classified into four stages: low-dose PDT using 0.5 microgram/mL BPD at 50 J/cm2 (stage I) resulted in incomplete cell eradication and significant IH at 2 weeks. Irradiation with 100 J/cm2 at the same BPD concentration (stage II) completely eradicated the cells in the artery wall at 24 h but still led to IH at 2 weeks. However, 25 micrograms/mL BPD at 100 J/cm2 (stage III) resulted in total cell eradication at 24 h and inhibition of IH at 2 weeks. In contrast, high-dose PDT with 25 micrograms/mL BPD and 200 J/cm2 (stage IV) led to thrombus development and vascular occlusion at 24 h. These data, demonstrating the different stages of PDT effects on injured arteries, emphasize the critical importance of appropriate PDT dosimetry for the effective inhibition of IH.


Assuntos
Lesões das Artérias Carótidas/tratamento farmacológico , Fotoquimioterapia/métodos , Animais , Lesões das Artérias Carótidas/metabolismo , Lesões das Artérias Carótidas/patologia , Fator 2 de Crescimento de Fibroblastos/metabolismo , Hiperplasia , Masculino , Fármacos Fotossensibilizantes/administração & dosagem , Porfirinas/administração & dosagem , Ratos , Ratos Sprague-Dawley
13.
Hepatology ; 27(3): 755-64, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9500704

RESUMO

We determined the functional role of nitric oxide (NO) and endothelins (ET), two potent vasoactive mediator systems in the liver, for the pathogenesis of sinusoidal perfusion failure and lethal hepatocyte injury after low-flow ischemia/reperfusion in the isolated perfused rat liver. NO synthase blockade with Nomega-nitro-L-arginine methyl ester (L-NAME) (10[-3] mol/L) before reperfusion prevented increased N02-/NO3- the final products of NO oxidation, which could be observed in the vehicle group. Epifluorescence microscopy revealed that the decrease in functional sinusoid density during reperfusion was much more profound compared with vehicle. This was associated with a lower surface PO2, a substantially higher number of nonviable hepatocytes, as assessed by in situ propidium iodide staining, and enhanced enzyme release into the perfusate compared with vehicle. In contrast, reperfusion in the presence of the endothelinA+B receptor antagonist bosentan (2 x 10(-4) mol/L) restored functional sinusoid density and surface PO2 to baseline values, resulted in a small reduction in the number of propidium iodide-positive hepatocytes, and caused similar increases in enzyme release as compared with vehicle. This indicates that hepatic generation of NO attenuates sinusoidal perfusion failure and improves liver tissue oxygenation, thus limiting hepatocyte injury during early reperfusion after hepatic low-flow ischemia. In contrast, endothelins counteract the microcirculatory effects of NO, i.e., mediate the no-reflow in hepatic sinusoids; however, the restoration of functional sinusoid density with bosentan resulted only in a small reduction in tissue damage, suggesting that additional components, which are independent of microcirculatory failure, contribute to hepatic reperfusion injury under these conditions.


Assuntos
Endotelinas/fisiologia , Fígado/irrigação sanguínea , Óxido Nítrico/fisiologia , Traumatismo por Reperfusão/etiologia , Animais , Bosentana , Corpos Cetônicos/metabolismo , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Ratos , Ratos Sprague-Dawley , Sulfonamidas/farmacologia
14.
Lasers Surg Med ; 23(5): 263-73, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9888322

RESUMO

BACKGROUND: Photodynamic therapy (PDT), the light activation of photosensitizer dyes for the production of free radicals, effectively inhibits experimental intimal hyperplasia with systemic administration of the photosensitizer. The local application of the photosensitizer directly into a vascular lesion to avoid systemic side effects and tightly control dose administration has theoretical appeal. The aim of this study was to quantify serum and arterial tissue uptake after site-specific photosensitizer delivery and, following PDT, determine its effectiveness at inhibiting intimal hyperplasia. STUDY DESIGN/MATERIALS AND METHODS: The rat common carotid artery was balloon-injured, pressurized at 400 mm Hg for 2 minutes with the photosensitizer dye benzoporphyrin-derivative (BPD), and irradiated with 690 nm laser light at a fluence of 100 J/cm2. Control animals were pressurized with saline only, or received no additional treatment than balloon-injury. RESULTS: Pressurization with BPD resulted in complete penetration of the intima and media and was associated with relatively high tissue, but almost no detectable serum BPD concentrations. No skin photosensitization or other systemic side effects were observed with photosensitizer administration. After 9 days, PDT-treated arteries displayed a significantly lower number of smooth muscle cells in the arterial wall than balloon-injured (P < 0.001) or saline-pressurized arteries (P < 0.0002), and no intimal hyperplasia. At 21 days, IH after PDT was significantly reduced as compared with balloon-injured (P < 0.0004), or saline-pressurized arteries (P < 0.003) with no arterial dilatation. CONCLUSIONS: Site-specific delivery of liposomal BPD followed by PDT represents a safe method to treat arteries, and may be effectively used in vivo to inhibit the development of intimal hyperplasia.


Assuntos
Artérias Carótidas/efeitos dos fármacos , Artérias Carótidas/patologia , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/administração & dosagem , Porfirinas/administração & dosagem , Túnica Íntima/efeitos dos fármacos , Túnica Íntima/patologia , Animais , Artérias Carótidas/metabolismo , Avaliação Pré-Clínica de Medicamentos , Hiperplasia/tratamento farmacológico , Hiperplasia/metabolismo , Hiperplasia/patologia , Imuno-Histoquímica , Injeções Intralesionais/métodos , Terapia a Laser , Masculino , Fármacos Fotossensibilizantes/farmacocinética , Porfirinas/farmacocinética , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Túnica Íntima/metabolismo , Verteporfina
15.
Zentralbl Chir ; 123(12): 1334-9, 1998.
Artigo em Alemão | MEDLINE | ID: mdl-10063541

RESUMO

During the last 4 years (11/93-11/97) 330 patients with acute bowel obstruction were treated and analysed retrospectively. 80% of the obstructions (n = 265) were in the small bowel and 20% (n = 65) in the large bowel localized. Adhesions were the main cause in 65.7% (n = 174) of all small bowel obstructions, and one third (35.1%, n = 61) of these patients were treated conservatively. In the large bowel, however, 37% were caused by obstructing colon carcinoma mainly localized in the rectosigmoid region. Mechanical bowel obstruction remains to be one of the most common emergencies in general surgery. A successful treatment is based on a rapid and correct diagnosis followed by an immediate surgical intervention if indicated. There are no reliable clinical, laboratory or radiological signs of bowel strangulation available. Preoperative diagnostic examinations should confirm bowel obstruction, determine its localization and origin and exclude other pathologies. Furthermore, it should help in selecting a patient subgroup with small bowel obstruction due to adhesions, which might be treated conservatively. Preoperative diagnostic procedures include case history, clinical examination, basic laboratory tests and a plain abdominal x-ray. In patients with suspected small bowel obstruction due to adhesions without any signs of strangulation a contrast medium follow-through study may be indicated. If the contrast medium fails to pass into the colon within 5 hours, a surgical exploration is recommended. In large bowel obstruction a contrast medium enema, a computed tomography or a colonoscopy are valuable diagnostic tools.


Assuntos
Obstrução Intestinal/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Diagnóstico Diferencial , Feminino , Humanos , Obstrução Intestinal/etiologia , Obstrução Intestinal/cirurgia , Intestino Grosso/cirurgia , Intestino Delgado/cirurgia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
16.
J Vasc Surg ; 26(2): 294-301, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9279318

RESUMO

PURPOSE: Photodynamic therapy (PDT), the light activation of photosensitizer dyes for the production of oxygen and other free radical moieties without the generation of heat, has been shown to inhibit the development of experimentally induced intimal hyperplasia. The host response to PDT, a form of vascular injury that results in complete vascular wall cell eradication, is devoid of inflammation and proliferation and promotes favorable vascular wall healing. These effects do not result in intimal hyperplasia and are suggestive of PDT-induced changes in the extracellular matrix (ECM). As a model to better understand the biologic consequences of PDT on the vascular wall matrix proteins, the effect of PDT was studied on the powerful matrix-resident mitogen basic fibroblast factor (bFGF) in vitro. METHODS: PDT (5 to 200 J/cm2, 100 mW/cm2, 675 nm) was used with the photosensitizer chloroaluminum sulfonated phthalocyanine (5 micrograms/ml) to inactivate bFGF in vitro while 100 J/cm2 of irradiation was administered 24 hours after 5 mg/ml of the photosensitizer was used in vivo. PDT was used on bFGF in solution and on endothelial cell-derived ECM. Enzyme-linked immunosorbent assay was used to quantitate bFGF in solution after PDT treatment or after extraction from the ECM by collagenase and heparin. Functional activity of matrix-associated bFGF was assessed by smooth muscle cell mitogenesis by 3H-thymidine incorporation. To demonstrate the in vivo relevance of these observations, immunohistochemical analysis of PDT-treated rat carotid arteries was undertaken. RESULTS: PDT eliminated detectable levels of bFGF in solution. PDT of ECM significantly reduced matrix-bound bFGF (1.0 +/- 0.6 vs 27.5 +/- 1.3 pg/ml; p < 0.0001). This reduction in bFGF after PDT of the ECM was associated with a decrease in vascular smooth muscle cell mitogenesis (52.4% +/- 4.6%; p < 0.0001) when plated on PDT-treated matrix compared with nontreated matrix. Quantitative replenishment of exogenous bFGF to PDT-treated matrix restored proliferation to baseline levels. PDT of rat carotid arteries demonstrated a loss of bFGF staining compared with control nontreated arteries. CONCLUSIONS: PDT inactivation of matrix-resident bFGF and possibly other bioactive molecules can provide a mechanism by which PDT suppresses smooth muscle cell proliferation in the vessel wall. This free radical-mediated alteration of matrix may contribute to favorable vascular healing when PDT is used for the inhibition of injury-induced intimal hyperplasia.


Assuntos
Matriz Extracelular/metabolismo , Fator 2 de Crescimento de Fibroblastos/fisiologia , Músculo Liso Vascular/fisiologia , Fotoquimioterapia , Animais , Anticorpos Monoclonais , Aorta/citologia , Bovinos , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Fator 2 de Crescimento de Fibroblastos/metabolismo , Ratos , Ratos Sprague-Dawley
17.
Cardiovasc Res ; 35(2): 334-40, 1997 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9349396

RESUMO

OBJECTIVE: Procedurally related vascular injury results in a smooth muscle cell (SMC) proliferative response which is in part initiated by SMC release of mitogens, including basic fibroblast growth factor (bFGF). This injury-induced proliferative response is believed to be a key event in intimal hyperplasia development. Photodynamic therapy (PDT), a novel approach found to be effective in inhibiting experimental intimal hyperplasia, produces cytotoxic free radicals resulting in localized SMC eradication. However, this form of SMC injury does not induce an inflammatory or proliferative response in the vessel wall. This study investigated whether PDT-generated free radicals could inactivate cell-associated bFGF normally released with cell injury. METHODS: PDT of bovine SMC was performed in vitro with the photosensitizer CASPc (5 micrograms/ml) and 675 nm laser light using three different fluences: 10, 50, and 100 J/cm2. After PDT, SMC viability was determined with the tetrazolium salt (MTT) assay and cell-associated bFGF was quantitated by ELISA. A SMC mitogenesis assay was utilized to detect cell-associated bFGF activity released with SMC injury. RESULTS: In a dose-dependent manner, PDT-generated free radicals reduced cell-associated bFGF levels. After PDT with 100 J/cm2, cell-associated bFGF content was reduced by 88% (P < 0.0002). Of special interest was the finding that PDT with 10 J/cm2 significantly (P < 0.0002) reduced cell viability to around 50%, without affecting cellular bFGF levels. Consequently, a higher PDT dose (100 J/cm2) was needed to significantly (P < 0.001) inhibit the SMC mitogenic response associated with SMC injury. CONCLUSION: These results provide a mechanism to explain how, unlike mechanical or other forms of SMC injury, optimal doses of PDT can locally eradicate medial vascular SMC without resulting in a bFGF-induced initiation of cell proliferation.


Assuntos
Fator 2 de Crescimento de Fibroblastos/metabolismo , Músculo Liso Vascular/efeitos da radiação , Fotoquimioterapia , Animais , Bovinos , Divisão Celular/efeitos da radiação , Células Cultivadas , Radicais Livres , Músculo Liso Vascular/citologia
18.
Ann Thorac Surg ; 63(5): 1461-3, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9146346

RESUMO

Primary malignant melanoma of the esophagus is an extremely rare tumor. In the absence of prospectively sampled data in the literature, the following case report and review of the literature indicate that surgical resection of the primary tumor and solitary metastases provides the longest survival times and, to date, is the treatment of choice.


Assuntos
Neoplasias Esofágicas/cirurgia , Melanoma/cirurgia , Idoso , Neoplasias Esofágicas/diagnóstico por imagem , Neoplasias Esofágicas/patologia , Humanos , Masculino , Melanoma/diagnóstico por imagem , Melanoma/patologia , Tomografia Computadorizada por Raios X
19.
Lab Invest ; 76(2): 257-66, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9042162

RESUMO

Photodynamic therapy (PDT), the production of cytotoxic free-radical moieties by light activation of photosensitizer dyes, is a novel approach to inhibit experimental intimal hyperplasia. Local eradication of vascular cells with this method in vivo is followed by expedient reendothelialization, and PDT of extracellular matrix (ECM) in vitro stimulates endothelial cell (EC) growth. This in vitro study explored one possible mechanism underlying these findings by investigating the effects of PDT on matrix-associated transforming growth factor-beta (TGF-beta), a potent inhibitor of EC growth. The ECM deposited by EC on tissue culture plates contained 85.4 +/- 10.2 pg/10 cm2 of TGF-beta, as measured by an ELISA. In contrast, after PDT of ECM, levels of TGF-beta could be barely be detected (0.2 +/- 0.5 pg/10 cm2). The functional consequence of this observation was demonstrated by the finding that PD1 of plates coated with a fibronectin-TGF-beta complex stimulated EC mitogenesis (102.3% +/- 19.3%, p < 0.0005) compared with the untreated control (44.1% +/- 13.5%). The inhibitory effect of ECM-associated TGF-beta on EC was further delineated by blocking its activity with a specific antibody. Whereas the antibody did not affect EC mitogenesis or PDT-treated matrix or matrix-free plates (101% +/- 8.8%, 105.6% +/- 9.8%), EC mitogenesis growing on ECM was significantly enhanced (125.9%, 17.5%, p < 0.05). Finally, SDS-PAGE analysis of PDT-treated TGF-beta in solution demonstrated that the PDT-mediated loss of TGF-beta activity was not associated with changes in its molecular weight. These data demonstrate that increased EC proliferation on PDT-treated matrix is, at least in part, mediated by inactivation of TGF-beta. PDT-removal of this EC growth inhibitor in the intima provides a mechanism by which PDT of the vascular wall could potentiate endothelial regrowth, a factor which may promote proper healing and result in the inhibition of intimal hyperplasia.


Assuntos
Matriz Extracelular/efeitos dos fármacos , Fotoquimioterapia , Fator de Crescimento Transformador beta/antagonistas & inibidores , Animais , Bovinos , Divisão Celular , Células Cultivadas , Meios de Cultivo Condicionados/química , Endotélio/citologia , Endotélio/efeitos dos fármacos , Endotélio/crescimento & desenvolvimento , Ensaio de Imunoadsorção Enzimática , Matriz Extracelular/metabolismo , Indóis/farmacologia , Compostos Organometálicos/farmacologia , Radiossensibilizantes/farmacologia , Fator de Crescimento Transformador beta/análise
20.
Thorac Cardiovasc Surg ; 44(6): 304-7, 1996 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9021908

RESUMO

Inhalative cigarette smoking is a major risk factor for atherosclerotic disease as well as primary carcinoma of the lung. On that account, this study was performed to determine the prevalence of primary lung cancer on admission in patients scheduled for vascular surgery. All patients presenting to our department for an intervention are screened for lung diseases. If this pretherapeutic examination suggests the existence of a lung tumor further diagnostic procedures are performed. Making use of a prospective computer-assisted patient-documentation system, we analysed incidental findings of lung cancer in those patients admitted for elective surgery. Between Jan. 1st 1990 and October 31st 1994, we electively treated 2214 patients with the diagnosis of vascular stenosis (n = 1711/77.3%) or atherosclerotic aneurysms (n = 503/22.7%) in our department. In 16 of these patients (m:f = 13:3; age 50-72 [mean: 61.1] years) a carcinoma of the lung was detected during preoperative diagnostic procedures, a prevalence of 0.72%. All these patients were smokers, with a daily inhalative nicotine consumption averaging 25 cigarettes per day for a mean of 35 years. 8 patients underwent a surgical (n = 6) or other invasive (n = 2) vascular interventions. In 8 patients no vascular intervention was performed because of the revealed lung carcinoma. The prevalence of lung cancer in a population of vascular patients in the present study is in accord with data of older investigations of high-risk groups. Only 2 out of 16 lung cancers were detected at a prognostically favourable stage. Smokers with symptoms of vascular disease should be carefully examined for signs of lung cancer.


Assuntos
Arteriosclerose/epidemiologia , Arteriosclerose/cirurgia , Neoplasias Pulmonares/epidemiologia , Idoso , Arteriosclerose/etiologia , Procedimentos Cirúrgicos Eletivos , Feminino , Humanos , Neoplasias Pulmonares/etiologia , Neoplasias Pulmonares/prevenção & controle , Masculino , Programas de Rastreamento , Sistemas Computadorizados de Registros Médicos , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Fumar/efeitos adversos , Fumar/epidemiologia
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