RESUMEN
Ion beam processes related to focused ion beam milling, surface patterning, and secondary ion mass spectrometry require precision and control. Quality and cleanliness of the sample are also crucial factors. Furthermore, several domains of nanotechnology and industry use nanoscaled samples that need to be controlled to an extreme level of precision. To reduce the irradiation-induced damage and to limit the interactions of the ions with the sample, low-energy ion beams are used because of their low implantation depths. Yet, low-energy ion beams come with a variety of challenges. When such low energies are used, the residual gas molecules in the instrument chamber can adsorb on the sample surface and impact the ion beam processes. In this paper we pursue an investigation on the effects of the most common contaminant, water, sputtered by ultralow-energy ion beams, ranging from 50 to 500 eV and covering the full range of incidence angles, using molecular dynamics simulations with the ReaxFF potential. We show that the expected sputtering yield trends are maintained down to the lowest sputtering yields. A region of interest with low damage is obtained for incidence angles around 60° to 75°. We also demonstrate that higher energies induce a larger removal of the water contaminant and, at the same time, induce an increased amorphization, which leads to a trade-off between sample cleanliness and damage.
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Focused ion beams (FIB) are a common tool in nanotechnology for surface analysis, sample preparation for electron microscopy and atom probe tomography, surface patterning, nanolithography, nanomachining, and nanoprinting. For many of these applications, a precise control of ion-beam-induced processes is essential. The effect of contaminations on these processes has not been thoroughly explored but can often be substantial, especially for ultralow impact energies in the sub-keV range. In this paper we investigate by molecular dynamics (MD) simulations how one of the most commonly found residual contaminations in vacuum chambers (i.e., water adsorbed on a silicon surface) influences sputtering by 100 eV argon ions. The incidence angle was changed from normal incidence to close to grazing incidence. For the simulation conditions used in this work, the adsorption of water favours the formation of defects in silicon by mixing hydrogen and oxygen atoms into the substrate. The sputtering yield of silicon is not significantly changed by the contamination, but the fraction of hydrogen and oxygen atoms that is sputtered largely depends on the incidence angle. This fraction is the largest for incidence angles between 70 and 80° defined with respect to the sample surface. Overall, it changes from 25% to 65%.
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This study was specifically focused on para-professional healthcare workers (PHCWs) who handle cytotoxic drugs and contaminated wastes at the Public Teaching Hospitals of Marseille (AP-HM), France. It first aimed at evaluating the knowledge and professional practice of the PHCWs who belong to a personnel category among the less informed and protected in hospitals. In a second time, this study also proposed to raise awareness, educate and train the staff on protective measures to minimise the exposure of the PHCWs to the potential toxicity of anticancer chemotherapy agents (or metabolites) when cleaning and handling both cytotoxic drugs and wastes. Among the 11 oncology units evaluated, 82% completed an assessment survey, 63% of which were PHCWs. Out of nine oncology units assessed, 89% reported limited knowledge of the general risk and of the safe handling of cytotoxic drugs, 89% reported using vinyl gloves which are the less protective ones. Forty-four per cent of the units used wet sweeping techniques for cleaning the floors, and 11% of the units did not have specific procedures for cleaning the equipments used for collecting contaminated excreta. Protective outer apparel was not always worn and chemotherapy wastes were not managed consistently between all units. Standardized procedures and guidelines to prevent occupational exposure were not used by PHCWs. More education and training are needed to improve safety.
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Antineoplásicos/efectos adversos , Citotoxinas/efectos adversos , Eliminación de Residuos Sanitarios/normas , Exposición Profesional/prevención & control , Personal de Hospital , Adulto , Descontaminación/normas , Educación Profesional/normas , Contaminación de Equipos/prevención & control , Femenino , Francia , Guantes Protectores , Conocimientos, Actitudes y Práctica en Salud , Hospitales Públicos , Hospitales de Enseñanza , Humanos , Masculino , Persona de Mediana Edad , Personal de Hospital/educación , Ropa de Protección/estadística & datos numéricos , Adulto JovenRESUMEN
Turnbull and Cutait described abdominoperineal pull-through followed by delayed coloanal anastomosis (DCA) in 1961. DCA could reduce anastomotic leaks, pelvic morbidity and use of stomas. Strong evidence about its clinical benefits is still lacking. This systematic review examined the clinical outcomes of DCA for the treatment of malignant or benign colorectal conditions. A systematic search of electronic medical databases was conducted. Two independent reviewers selected studies, extracted data and assessed risk of bias. The primary outcome was pelvic morbidity (anastomotic leak, pelvic abscess or sepsis, use of stoma). Fecal continence and survival data were also analyzed. From 1,251 citations, we included seven observational studies including 1,124 patients. All included studies were considered at high risk of bias. Two studies comparing DCA with immediate anastomosis reported a significant decrease in anastomotic leak, and pelvic abscess or sepsis. Low rates of pelvic morbidity were reported in the other five studies: anastomotic leak 0-7 %, pelvic abscess 0-11.8 % and pelvic sepsis 6.8-10 %. Rates of permanent stoma after DCA were low in six studies (1-6 %), with one study reporting an incidence of 25 %. Fecal continence was reported as satisfying in all studies. No differences were observed in a comparative setting. Survival data were reported in four studies. Clinical heterogeneity and methodological issues precluded meta-analysis. Based on retrospective evidence, DCA offers a low rate of anastomotic leak, pelvic morbidity and use of stoma, with reasonable fecal continence. Results are encouraging, but prospective studies are needed for comparison with standard of care.
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Canal Anal/cirugía , Colon/cirugía , Enfermedades del Colon/cirugía , Enfermedades del Recto/cirugía , Anastomosis Quirúrgica/métodos , Humanos , Complicaciones Posoperatorias , Análisis de SupervivenciaRESUMEN
Several studies have been published in which holistic approaches were used to characterise the proteome and transcriptome of human platelets. The key intent being that a deeper understanding of the normal and aberrant physiological functions of platelets can only be achieved if most biomolecular building blocks are mapped. Here we present the application of recently developed novel technologies that overcome some of the shortcomings of gel-based proteomics. Central in our approach is the so-called combined fractional diagonal chromatography (COFRADIC)-technology in which sets of representative peptides are sorted in a diagonal RP chromatographic system through a specific modification of their side chain. In this study we combined three different COFRADIC sorting techniques to analyse the proteome of human platelets. Methionyl, cysteinyl and amino terminal peptides were isolated and analysed by MS/MS. Merging the peptide identifications obtained after database searching resulted in a core set of 641 platelet proteins, which comprises the largest set identified today. In comparison to previously published platelet proteomes, we identified 404 novel platelet proteins containing a high number of hydrophobic membrane proteins and hypothetical proteins. Furthermore we discuss the observed characteristics and potential benefits of each of the different COFRADIC technologies for proteome analysis and highlight important issues that need to be considered when searching sequence databases using data obtained in peptide-centric, non-gel proteomics studies.
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Plaquetas/metabolismo , Biología Computacional/métodos , Proteómica/métodos , Animales , Cromatografía/métodos , Bases de Datos de Proteínas , Humanos , Espectrometría de Masas , Mapeo Peptídico , Péptidos/química , Isoformas de Proteínas , Proteoma , ARN Mensajero/metabolismo , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
BACKGROUND: This purpose of this study was to examine whether survival is affected when laparoscopic resections for colorectal cancer are converted to open surgery. METHODS: A prospective database of 377 consecutive laparoscopic resections for colorectal cancer performed between November 1991 and June 2002 was reviewed. The TNM classification for colorectal cancer and the Kaplan-Meier method were used to determine survival curves for each group. RESULTS: Conversion to an open procedure was required in 46 cases (12.8%). Converted and laparoscopic groups were similar in age, sex, comorbidities, and location and size of tumor. The converted group had a significantly higher weight (75 kg vs 69 kg, p = 0.013) and conversion score (2.18 vs. 1.87, p = 0.005). Patients with stage IV disease were significantly more likely to be converted than those with stage I-III disease (23.0% vs 11.2%, p = 0.04). There was no difference in the conversion rate between patients with stage I (14%), II (8%), or III (13%) colorectal cancers. Median follow-up was 30.5 months for stage I-III and 10.8 months for stage IV cancers. There were 190 patients followed at least 2 years and 73 patients followed at least 5 years. Survival curves demonstrate significantly lower 2-year survival after converted procedures as compared to laparoscopic (75.7% vs 87.2%, p = 0.02), with a trend toward lower 5-year survival (61.9% vs 69.7%, p = 0.077). CONCLUSIONS: Survival rates at 2 and 5 years are lower for patients in the converted group compared to patients with LR. This finding could have serious impact on the treatment of patients with colorectal cancer. Further confirmation is required.
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Colectomía/métodos , Neoplasias Colorrectales/cirugía , Laparoscopía , Anciano , Neoplasias Colorrectales/patología , Femenino , Humanos , Complicaciones Intraoperatorias , Escisión del Ganglio Linfático , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Evaluación de Procesos y Resultados en Atención de Salud , Análisis de SupervivenciaRESUMEN
BACKGROUND: HIV lipodystrophy syndrome, characterized by a significant excess of visceral adiposity and a reduced subcutaneous fat mass in association with insulin resistance and dyslipidemia, still affects the majority of antiretroviral-treated HIV-infected patients. The therapeutic management of this syndrome has not yet been well established. Benfluorex is known to decrease insulin resistance with no side effects on lactate levels in HIV-negative patients. METHOD: We conducted an open-label study of benfluorex (150 mg, 2-3 times a day) that was prescribed for 60 HIV-infected patients who were diagnosed with glucose metabolism abnormalities by oral glucose tolerance test (OGTT); 47 of these patients had visceral fat accumulation measured by computed tomography (VAT). Median follow-up was 12 months (interquartile range [IQR] = 6-12 months). The great majority of patients (90%) were treated with at least triple therapy (in 70% the therapy included at least one PI), with a nonsignificant change over the study period. RESULTS: Added to antiretroviral therapy, benfluorex improved OGTT in 47/60 cases, including total normalization in 34/60 without lactate concentration modification. A trend toward a decrease in VAT distribution was observed (p =.06). No significant difference was observed in subcutaneous fat distribution, although an increase in subcutaneous thigh adipose tissue was observed in 17/47 (36.2%) cases and 6 patients (12.7%) presented both subcutaneous fat increase and VAT decrease.
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Fenfluramina/análogos & derivados , Fenfluramina/uso terapéutico , Síndrome de Lipodistrofia Asociada a VIH/tratamiento farmacológico , Hipolipemiantes/uso terapéutico , Resistencia a la Insulina , Tejido Adiposo/efectos de los fármacos , Adulto , Fármacos Anti-VIH/administración & dosificación , Esquema de Medicación , Femenino , Fenfluramina/administración & dosificación , Prueba de Tolerancia a la Glucosa , Síndrome de Lipodistrofia Asociada a VIH/complicaciones , Humanos , Hipolipemiantes/administración & dosificación , Masculino , Persona de Mediana Edad , Resultado del TratamientoRESUMEN
We report upon a novel procedure to specifically isolate cysteine-containing peptides from a complex peptide mixture. Cysteines are converted to hydrophobic residues by mixed disulfide formation with Ellman's reagent. Proteins are subsequently digested with trypsin and the generated peptide mixture is a first time fractionated by reverse-phase high-performance liquid chromatography. Cysteinyl-peptides are isolated out of each primary fraction by a reduction step followed by a secondary peptide separation on the same column, performed under identical conditions as for the primary separation. The reducing agent removes the covalently attached group from the cysteine side chain, making cysteine-peptides more hydrophilic and, thereby, such peptides can be specifically collected during the secondary separation and are finally used to identify their precursor proteins using automated liquid chromatography tandem mass spectrometry. We show that this procedure efficiently isolates cysteine-peptides, making the sample mixture less complex for further analysis. This method was applied for the analysis of the proteomes of human platelets and enriched human plasma. In both proteomes, a significant number of low abundance proteins were identified next to extremely abundant ones. A dynamic range for protein identification spanning 4-5 orders of magnitude is demonstrated.
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Plaquetas/química , Proteínas Sanguíneas/análisis , Péptidos/análisis , Proteoma , Cromatografía Líquida de Alta Presión/métodos , Cisteína/química , Ácido Ditionitrobenzoico/química , Humanos , Espectrometría de Masas/métodos , Análisis de Secuencia de Proteína/métodos , Tripsina/químicaRESUMEN
BACKGROUND: Laparoscopic colorectal surgery has clear advantages over open surgery; however, the effectiveness of the approach depends on the conversion rate. The objective of this work was to prospectively validate a model that would predict conversion in laparoscopic colorectal surgery. METHODS: A simple clinical model for predicting conversion in laparoscopic colorectal surgery was previously developed based on a multivariable logistic regression analysis of 367 procedures. This model was applied prospectively to a follow-up group of 248 procedures by the same team, including 54 procedures performed by one new fellowship-trained surgeon. RESULTS: Patients in the follow-up group were more likely to have cancer (56% vs 44%, p = 0.007) and were more obese (median, 71.0 vs 66.0 kg; p < 0.001). The rate of conversion in the follow-up group was unchanged (8.9% vs 9.0%, p > 0.05). Despite expected trends toward increasing risk of conversion with weight level (<60 kg, 6.8%; 60-<90 kg, 9.0%; >90 kg, 12.1%; p > 0.05) and malignancy (10.1% vs 7.3%, p > 0.05), the model did not distinguish well between groups at risk for conversion. Contrary to the model, however, the fellowship-trained surgeon had a conversion rate that was not higher than that of the other, more experienced surgeons (7.3% vs 9.3%, p > 0.05) even though he was less experienced, and operating on patients who were more obese (median, 75.0 vs 70 kg; p = 0.02) and more likely to have cancer (59% vs 55%, p > 0.05). Recalculated conversion scores that excluded the inexperience point for the fellowship-trained surgeon showed a good fit for the model. Considering the original and follow-up experience together (615 cases), the model clearly stratifies patients into low (0 points), medium (1-2 points), and high risk (3-4 points) for conversion, with respective rates of 2.9%, 8.1%, and 20% ( p = 0.001). CONCLUSION: This model appears to be a valid predictor of conversion to open surgery. Fellowship training may provide sufficient experience so that learning curve issues are redundant in early practice. This model now requires validation by other centers.
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Enfermedades del Colon/cirugía , Becas , Cirugía General/educación , Laparoscopía/estadística & datos numéricos , Enfermedades del Recto/cirugía , Peso Corporal , Neoplasias Colorrectales/epidemiología , Neoplasias Colorrectales/cirugía , Femenino , Estudios de Seguimiento , Humanos , Aprendizaje , Modelos Logísticos , Masculino , Modelos Teóricos , Obesidad/complicaciones , Estudios Prospectivos , Resultado del TratamientoRESUMEN
Current non-gel techniques for analyzing proteomes rely heavily on mass spectrometric analysis of enzymatically digested protein mixtures. Prior to analysis, a highly complex peptide mixture is either separated on a multidimensional chromatographic system or it is first reduced in complexity by isolating sets of representative peptides. Recently, we developed a peptide isolation procedure based on diagonal electrophoresis and diagonal chromatography. We call it combined fractional diagonal chromatography (COFRADIC). In previous experiments, we used COFRADIC to identify more than 800 Escherichia coli proteins by tandem mass spectrometric (MS/MS) analysis of isolated methionine-containing peptides. Here, we describe a diagonal method to isolate N-terminal peptides. This reduces the complexity of the peptide sample, because each protein has one N terminus and is thus represented by only one peptide. In this new procedure, free amino groups in proteins are first blocked by acetylation and then digested with trypsin. After reverse-phase (RP) chromatographic fractionation of the generated peptide mixture, internal peptides are blocked using 2,4,6-trinitrobenzenesulfonic acid (TNBS); they display a strong hydrophobic shift and therefore segregate from the unaltered N-terminal peptides during a second identical separation step. N-terminal peptides can thereby be specifically collected for further liquid chromatography (LC)-MS/MS analysis. Omitting the acetylation step results in the isolation of non-lysine-containing N-terminal peptides from in vivo blocked proteins.
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Plaquetas/química , Espectrometría de Masas/métodos , Péptidos/química , Proteoma/química , Plaquetas/metabolismo , Membrana Celular/metabolismo , Citosol/química , Humanos , Péptidos/análisis , Péptidos/metabolismo , Proteoma/análisis , Proteoma/metabolismoRESUMEN
A novel gel-free proteomic technology was used to identify more than 800 proteins from 50 million Escherichia coli K12 cells in a single analysis. A peptide mixture is first obtained from a total unfractionated cell lysate, and only the methionine-containing peptides are isolated and identified by mass spectrometry and database searching. The sorting procedure is based on the concept of diagonal chromatography but adapted for highly complex mixtures. Statistical analysis predicts that we have identified more than 40% of the expressed proteome, including soluble and membrane-bound proteins. Next to highly abundant proteins, we also detected low copy number components such as the E. coli lactose operon repressor, illustrating the high dynamic range. The method is about 100 times more sensitive than two-dimensional gel-based methods and is fully automated. The strongest point, however, is the flexibility in the peptide sorting chemistry, which may target the technique toward quantitative proteomics of virtually every class of peptides containing modifiable amino acids, such as phosphopeptides, amino-terminal peptides, etc., adding a new dimension to future proteome research.
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Proteínas de Escherichia coli/análisis , Metionina/análisis , Péptidos/química , Proteoma/análisis , Algoritmos , Cromatografía/métodos , Escherichia coli/química , Proteínas de Escherichia coli/aislamiento & purificación , Péptidos/aislamiento & purificaciónRESUMEN
BACKGROUND: Laparoscopic resection for rectal cancer is controversial. Actuarial survival and local recurrence rates have not been determined. METHODS: A prospective database containing 80 consecutive unselected laparoscopic resections of rectal cancers performed between November 1991 and 1999 was reviewed. Local recurrence was defined as any detectable local disease at follow-up assessment occurring either alone or in conjunction with generalized recurrence. The tumor node metastases (TNM) classification for colorectal cancers and the Kaplan-Meier method were used to determine staging and survival curves. The mesorectal excision technique was used during surgery. RESULTS: The median follow-up period was 31 months for patients with stages I, II, and III cancer, and 15.5 months for patients with stage IV cancer. The overall 5-year survival rate was 65.1% for all cancer stages and 72.1% for stages I, II, and III cancer. No trocar-site recurrence was observed. The overall local recurrence rate was 3.75% (3/80) for all cancer stages, and 4.3% (3/70) for stages I, II, and III cancer. CONCLUSIONS: The survival and local recurrence rates for patients with rectal cancer treated by laparoscopic mesorectal excision do not differ negatively from those in the literature for open mesorectal excision. Further validation is needed.
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Adenocarcinoma/mortalidad , Adenocarcinoma/cirugía , Recurrencia Local de Neoplasia , Neoplasias del Recto/mortalidad , Neoplasias del Recto/cirugía , Adenocarcinoma/patología , Anciano , Anciano de 80 o más Años , Femenino , Estudios de Seguimiento , Humanos , Laparoscopía , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Prospectivos , Neoplasias del Recto/patología , Tasa de Supervivencia , Resultado del TratamientoRESUMEN
STUDY AIM: To evaluate the influence of a pylorus-preserving on the morbidity and prognosis of patient with pancreaticoduodenectomy for adenocarcinoma of pancreas. PATIENTS AND METHODS: Between 1985 and 1999, 183 patients were operated on for pancreatic adenocarcinoma. Among them, 63 patients (40 men, mean age 63 years, range 41-77 years) had curative resection and were included in this retrospective study. They were classified according to the type of resection. In the group I, the procedure included a pylorus-preserving pancreaticoduodenectomy (n = 35). In the group II, the procedure included polar inferior gastrectomy (n = 28). The prognosis was compared. Parameters for comparison were rate of local recurrence, rate of metastatic evolution and duration of survival. RESULTS: The operative length and mortality rate (group I: 0%, group II: 3%), general (p = 0.37) and specific morbidity (p = 0.30), frequency of delayed gastric emptying were similar in the 2 groups (group I: 20%, group II: 35%, p = 0.88). The duration of naso-gastic aspiration was shorter in the group I (6 days vs 8, p = 0.01). The prognosis was the same in the 2 groups (metastasis: group I: 39%, group II: 56%, p = 0.12, local recurrence: group I: 58%, group II: 43%, p = 0.09, mean survival: group I: 18 months, group II: 19 months, p = 0.77). CONCLUSION: These results suggest that pylorus preserving pancreatoduodenectomy could be performed for patients with adenocarcinoma of the head of the pancreas and does not compromise survival.
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Adenocarcinoma/cirugía , Recurrencia Local de Neoplasia , Neoplasias Pancreáticas/cirugía , Pancreaticoduodenectomía/métodos , Complicaciones Posoperatorias , Píloro/cirugía , Adenocarcinoma/patología , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Morbilidad , Metástasis de la Neoplasia , Neoplasias Pancreáticas/patología , Pronóstico , Estudios Retrospectivos , Análisis de SupervivenciaRESUMEN
BACKGROUND: Ventilator-associated pneumonia (VAP) has been implicitly accused of increasing mortality. However, it is not certain that pneumonia is responsible for death or whether fatal outcome is caused by other risk factors for death that exist before the onset of pneumonia. The aim of this study was to evaluate the attributable mortality caused by VAP by performing a matched-paired, case-control study between patients who died and patients who were discharged from the intensive care unit after more than 48 h of mechanical ventilation. METHODS: During the study period, 135 consecutive deaths were included in the case group. Case-control matching criteria were as follows: (1) diagnosis on admission that corresponded to 1 of 11 predefined diagnostic groups; (2) age difference within 10 yr; (3) sex; (4) admission within 1 yr; (5) APACHE II score within 7 points; (6) ventilation of control patients for at least as long as the cases. Precise clinical, radiologic, and microbiologic definitions were used to identify VAP. RESULTS: Analysis was performed on 108 pairs that were matched with 91% of success. There were 39 patients (36.1%) who developed VAP in each group. Multivariate analysis showed that renal failure, bone marrow failure, and treatment with corticosteroids but not VAP were independent risk factors for death. There was no difference observed between cases and controls concerning the clinical and microbiologic diagnostic criteria for pneumonia. CONCLUSION: Ventilator-associated pneumonia does not appear to be an independent risk factor for death.
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Neumonía Bacteriana/etiología , Ventiladores Mecánicos/efectos adversos , Adulto , Anciano , Antibacterianos/uso terapéutico , Estudios de Casos y Controles , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Análisis Multivariante , Neumonía Bacteriana/tratamiento farmacológico , Neumonía Bacteriana/mortalidad , Factores de RiesgoRESUMEN
BACKGROUND: We set out to determine the rate and pattern of septic complications of the surgical wound, abdominal cavity, and urinary and respiratory tracts following laparoscopic colorectal resection. METHODS: A longitudinal database of 500 consecutive cases of colorectal resections was reviewed. RESULTS: The total wound infection rate was 7.2% (36/500) and included infections of the abdominal wall wounds (32/500, 6.4%) and the perineal wounds (4/50, 8%). The anastomotic leak rate in 418 patients who underwent resection with primary anastomosis was 3.3% (14/418). Intraabdominal abscesses were diagnosed in 1% (5/500) of patients. Urinary tract infections were rare (3/500, 0.6%), as was postoperative pneumonia (6/500, 1%). CONCLUSIONS: This study confirms the low rate of postoperative pneumonia observed with all other minimally invasive procedures. Intraabdominal abscesses, urinary tract infections, and postoperative pneumonia occur considerably less frequently than in reported historical controls for open surgery. The rates of abdominal wound infection and anastomotic leak in laparoscopic colorectal resection appear to be equivalent to traditional surgery, whereas the rate of perineal wound sepsis is lower. Comparative studies are needed to determine the differential costs of the septic episodes associated with the two approaches.
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Neoplasias Colorrectales/cirugía , Laparoscopía/efectos adversos , Sepsis/epidemiología , Infección de la Herida Quirúrgica/epidemiología , Absceso/epidemiología , Absceso/etiología , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Niño , Neoplasias Colorrectales/mortalidad , Femenino , Humanos , Incidencia , Laparoscopía/métodos , Masculino , Persona de Mediana Edad , Neumonía/epidemiología , Neumonía/etiología , Probabilidad , Pronóstico , Sistema de Registros , Medición de Riesgo , Factores de Riesgo , Sepsis/etiología , Distribución por Sexo , Estadísticas no Paramétricas , Infección de la Herida Quirúrgica/etiología , Tasa de Supervivencia , Infecciones Urinarias/epidemiología , Infecciones Urinarias/etiologíaRESUMEN
PURPOSE: The purpose of this review was to define the learning curve for laparoscopic colorectal resections. METHODS: A prospectively accumulated, computerized database of all laparoscopic colorectal resections performed by three surgeons between April 1991 and March 1999 was reviewed. RESULTS: A total of 461 consecutive resections were evenly distributed among three surgeons (141, 155, and 165). Median operating time was 180 minutes for Cases 1 to 30 in each surgeon's experience and declined to a steady state (150-167.5 minutes) for Cases 31 and higher. Subsequently, Cases 1 to 30 were considered "early experience," whereas Cases 31 and higher were combined as "late experience" for statistical analysis. There were no significant differences between patients undergoing resections in the early experience and those undergoing resections in the late experience with respect to age, weight, or proportion of patients with malignancy, diverticulitis, or inflammatory bowel disease. There were greater proportions of males (42 vs. 54 percent, P = 0.046) and rectal resections performed (14 vs. 32 percent, P = 0.002) in the late experience. Trends toward declining rates of intraoperative complications (9 vs. 7 percent, P = 0.70) and conversion to open surgery (13.5 vs. 9.7 percent, P = 0.39) were observed with experience. Median operating time (180 vs. 160 minutes, P < 0.001) and overall length of postoperative hospital stay (6.5 vs. 5 days, P < 0.001) declined significantly with experience. There was no difference in the rate of postoperative complications between early and late experience (30 vs. 32 percent, P = 0.827). CONCLUSIONS: The learning curve for performing colorectal resections was approximately 30 procedures in this study, based on a decline in operating time, intraoperative complications, and conversion rate. Learning was also extended to clinical care because it was appreciated that patients could be discharged to their homes more quickly.
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Procedimientos Quirúrgicos del Sistema Digestivo , Laparoscopía , Competencia Clínica , Colon/cirugía , Neoplasias Colorrectales/cirugía , Procedimientos Quirúrgicos del Sistema Digestivo/estadística & datos numéricos , Femenino , Humanos , Complicaciones Intraoperatorias/epidemiología , Laparoscopía/estadística & datos numéricos , Aprendizaje , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Estudios Prospectivos , Recto/cirugía , Factores de TiempoRESUMEN
OBJECTIVE: To compare the effectiveness and safety of low-dose unfractionated heparin and a low-molecular-weight heparin as prophylaxis against venous thromboembolism after colorectal surgery. METHODS: In a multicenter, double-blind trial, patients undergoing resection of part or all of the colon or rectum were randomized to receive, by subcutaneous injection, either calcium heparin 5,000 units every 8 hours or enoxaparin 40 mg once daily (plus two additional saline injections). Deep vein thrombosis was assessed by routine bilateral contrast venography performed between postoperative day 5 and 9, or earlier if clinically suspected. RESULTS: Nine hundred thirty-six randomized patients completed the protocol and had an adequate outcome assessment. The venous thromboembolism rates were the same in both groups. There were no deaths from pulmonary embolism or bleeding complications. Although the proportion of all bleeding events in the enoxaparin group was significantly greater than in the low-dose heparin group, the rates of major bleeding and reoperation for bleeding were not significantly different. CONCLUSIONS: Both heparin 5,000 units subcutaneously every 8 hours and enoxaparin 40 mg subcutaneously once daily provide highly effective and safe prophylaxis for patients undergoing colorectal surgery. However, given the current differences in cost, prophylaxis with low-dose heparin remains the preferred method at present.
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Anticoagulantes/uso terapéutico , Colectomía/métodos , Enoxaparina/uso terapéutico , Heparina/uso terapéutico , Recto/cirugía , Pérdida de Sangre Quirúrgica , Canadá/epidemiología , Método Doble Ciego , Femenino , Humanos , Inyecciones Subcutáneas , Complicaciones Intraoperatorias/epidemiología , Complicaciones Intraoperatorias/prevención & control , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/prevención & control , Hemorragia Posoperatoria/epidemiología , Estudios Prospectivos , Trombocitopenia/epidemiología , Trombocitopenia/etiología , Tromboembolia/epidemiología , Tromboembolia/prevención & control , Trombosis de la Vena/epidemiología , Trombosis de la Vena/prevención & controlRESUMEN
BACKGROUND AND PURPOSE: The aim of this study was to assess tolerance and efficacy of gamma knife radiosurgery on vestibular schwannomas for patients affected with neurofibromatosis type 2. METHODS: Between July 1992 and December 1997, a gamma knife procedure was performed on 35 vestibular schwannomas affecting 27 patients (12 females and 15 males, mean age=27 years-old, range: 14-65). Fifteen of the patients were included in the Wishart subtype (severe form) and 12 patients in the Gardner subtype (mild form). This group of 27 patients represented 8,2% of the total group of vestibular schwannomas radiosurgically treated by our team. The mean tumor volume was 4,000 mm(3) (range: 400-14,400 mm(3)) and staging according to Koos classification was 9 stage 2 tumors (extension in the cerebellopontine angle), 19 stage 3 tumors (in contact with the brain stem or cerebellum) and 7 stage 4 tumors (compression of axial structures). The delivered mean marginal dose (50% isodose) was 13 Gy (range: 10-18 Gy). After the treatment, the mean clinical and radiological follow-up was 32 months (range: 6-70). RESULTS: Twenty six (74%) of the treated tumors were controlled by the treatment (15 stabilizations and 11 regressions of the tumor volume) at last follow-up. One microsurgical removal was required in a growing stage 4 tumor and in 2 cases of growing stage 3 tumors. Three post-radiosurgical facial nerve deficits (9%) were observed, 2 of them were transient. According to the Gardner and Robertson classification, classes I (good) and II (serviceable) hearing were preserved at last follow-up in 57% of the patients having the same hearing level prior to the gamma knife. CONCLUSIONS: Our experience confirms that tolerance of gamma knife radiosurgery compares favorably with microsurgery of bilateral vestibular schwannomas. This treatment should be restricted to small and medium growing tumors. Treatment strategy of neurofibromatosis type 2 patients should be planned by multidisciplinary experienced teams disposing of the whole armamentarium. A longer follow-up study is required to confirm the current results regarding the tumor control rate.
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Neurofibromatosis 2/cirugía , Radiocirugia , Adolescente , Adulto , Anciano , Sordera/etiología , Enfermedades del Nervio Facial/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Radiocirugia/efectos adversos , Estudios RetrospectivosRESUMEN
PURPOSE: This was a multicenter, randomized, controlled trial to compare the effectiveness of topical nitroglycerin with internal sphincterotomy in the treatment of chronic anal fissure. METHODS: Patients with symptomatic chronic anal fissures were randomly assigned to 0.25 percent nitroglycerin tid or internal sphincterotomy. Both groups received stool softeners and fiber supplements and were assessed at six weeks and six months. RESULTS: Ninety patients were accrued, but 8 were excluded from the analysis because they refused internal sphincterotomy after randomization (6), the fissure healed before surgery (1), or a fissure was not observed at surgery (1). There were 38 patients in the internal sphincterotomy group (22 males; mean age, 40.3 years) and 44 patients in the nitroglycerin group (15 males; mean age, 38.7 years). At six weeks 34 patients (89.5 percent) in the internal sphincterotomy group compared with 13 patients (29.5 percent) in the nitroglycerin group had complete healing of the fissure (P = 5x10(-8)). Five of the 13 patients in the nitroglycerin group relapsed, whereas none in the internal sphincterotomy group did. At six months fissures in 35 (92.1 percent) patients in the internal sphincterotomy group compared with 12 (27.2 percent) patients in the nitroglycerin group had healed (P = 3x10(-9)). One (2.6 percent) patient in the internal sphincterotomy group required further surgery for a superficial fistula compared with 20 (45.4 percent) patients in the nitroglycerin group who required an internal sphincterotomy (P = 9x10(-6)). Eleven (28.9 percent) patients in the internal sphincterotomy group developed side effects compared with 37 (84 percent) patients in the nitroglycerin group (P<0.0001). Nine (20.5 percent) patients discontinued the nitroglycerin because of headaches (8) or a severe syncopal attack (1). CONCLUSIONS: Internal sphincterotomy is superior to topical nitroglycerin 0.25 percent in the treatment of chronic anal fissure, with a high rate of healing, few side effects, and low risk of early incontinence. Thus, internal sphincterotomy remains the treatment of choice for chronic anal fissure.
Asunto(s)
Canal Anal/cirugía , Fisura Anal/tratamiento farmacológico , Fisura Anal/cirugía , Nitroglicerina/uso terapéutico , Vasodilatadores/uso terapéutico , Administración Tópica , Adulto , Anciano , Femenino , Fisura Anal/patología , Humanos , Masculino , Persona de Mediana Edad , Nitroglicerina/administración & dosificación , Resultado del Tratamiento , Vasodilatadores/administración & dosificaciónRESUMEN
The real cost of medical consumption was compared with the proportion of medication consumption of (the) GHM n(o) 681 (homogeneous group of patients, chemotherapy for cancer in day care) in the French case mix system (PMSI). For those patients in our thoracic oncology unit (Sainte-Marguerite Hospital, Marseille, France), the real medication cost was calculated from prices paid by the hospital, then compared to the expected expenditures for the medication consumption of the GHM 681, i.e. 678 French francs (24.1% of the 225 ISA points (synthetic activity index)). Over a period of 2 months in 1998, 87 patients (mean age 63 +/- 11) had 194 chemotherapy sessions in day care, with multi-drug therapy in 38 cases. Vinorelbine or gemcitabine represented 81% of the single drug chemotherapy. In 84% of the single drug and 76% of the multi-drug chemotherapy, the real cost of medication consumption was above the allocated budget. The mean cost for single drug chemotherapy was 1722 FF and 2920 FF for multi-drug chemotherapy. The budget allocated by the PMSI shows a deficit in the most cases. To avoid a restriction in the use of some drugs, it appears that the French system of budget evaluation needs to be improved.