Endovascular stent placement for angioplasty-induced venous rupture related to the treatment of hemodialysis grafts.

PURPOSE: To assess the use of endovascular stents for treating rupture after percutaneous transluminal angioplasty (PTA) in the maintenance of hemodialysis grafts. MATERIALS AND METHODS: From February 1, 1994, to August 1, 1997, 683 hemodialysis-related angioplasty procedures were performed on 277 patients to treat thrombosed or poorly functioning polytetrafluoroethylene (PTFE) hemodialysis bridge grafts. In each of these procedures, angioplasty of the venous anastomosis or the outflow vein was performed. This study is a retrospective review to analyze uncovered endovascular stents placed to treat ruptures after PTA. RESULTS: Fourteen ruptures were treated with use of an uncovered metal stent. Stent placement was technically successful in 11 of 14 patients, with clinical success in 11 of 14 cases. The primary patencies at 30, 60, 90, and 120 days were calculated by means of Kaplan-Meier life-table analysis; these were 63%, 54%, 46%, and 46%, respectively. The secondary patencies at 60, 120, and 180 days were 85%, 75%, and 75%, respectively. No complications were attributable to stent placement. The results are comparable to those of stents placed for reasons other than rupture, and support the efficacy of their use for this indication. CONCLUSION: Endovascular stent placement is a safe and effective means of salvaging angioplasty-induced rupture that occurs during the treatment of hemodialysis grafts.

Patency of Wallstents placed across the venous anastomosis of hemodialysis grafts after percutaneous recanalization.

PURPOSE: To determine the patency of Wallstents placed across the venous anastomosis of prosthetic bridge grafts after percutaneous graft recanalization. MATERIALS AND METHODS: Wallstents were placed across 26 lesions at the venous anastomosis of polytetrafluoroethylene (PTFE) grafts in 25 patients (11 men, 14 women; age range, 29-83 years; mean age, 65.4 years) after pulse-spray pharmacomechanical thrombolysis. Indications for stent deployment included acute angioplasty failure, rapid restenosis, and vessel perforation. RESULTS: The initial success rate was 100%. The mean primary graft patency rates (+/- standard error) at 3 and 6 months were 34% +/- 9 and 27% +/- 9, respectively. Secondary patency rates were 77% +/- 8 at 3 months, 72% +/- 9 at 6 months, and 50% +/- 10 at 12 months. Eight of the 26 grafts continued to be used for hemodialysis at the end of follow-up. CONCLUSION: After angioplasty failure or vessel perforation, Wallstent placement at the venous anastomosis of recanalized PTFE grafts can salvage hemodialysis access function. The results of this study indicate that the 1-year secondary patency rate of these grafts is 50%, which approaches the reported rates of patency after balloon dilation as part of percutaneous graft recanalization.

Blood lead levels in children aged 24 to 36 months in Vancouver.

OBJECTIVES: To determine the blood lead levels in children and to identify risk factors for elevated levels. DESIGN: Cross-sectional study. SETTING: Vancouver. PARTICIPANTS: Random sample of children aged 24 to 36 months, born and still resident in Vancouver. The sample was stratified proportionally by the median annual family income in the census tract where each family resided. OUTCOME MEASURES: Blood lead levels and risk factors for elevated blood lead levels, determined from a questionnaire administered to parents. RESULTS: Of the children in the sample, 42% (178/422) were ineligible or could not be located. Of the remaining children, 73% (177/244) participated and adequate blood specimens were obtained from 172. The mean blood lead level was 0.29 mumol/L (standard deviation 0.13 mumol/L). (A blood lead level of 1 mumol/L is equivalent to 20.7 micrograms/dL.) The lowest level was 0.06 mumol/L, and the highest was 0.85 mumol/L. Of children with adequate samples, 8.1% (14/172) had blood lead levels of 0.48 mumol/L or higher, and 0.6% (1/172) had a level higher than 0.72 mumol/L. The logarithms of the levels were normally distributed, with a geometric mean (GM) of 0.26 mumol/L (geometric standard deviation 1.56). Of approximately 70 possible predictors of blood lead levels analysed, those that showed a statistically significant association (p < 0.05) with increased blood lead levels were soldering performed in the home as part of an electronics hobby (GM blood lead level 0.34 mumol/L, 95% confidence interval [CI] 0.27 to 0.39 mumol/L), aboriginal heritage (GM blood lead level 0.33 mumol/L, 95% CI 0.28 to 0.39 mumol/L), dwelling built before 1921 (GM blood lead level 0.32 mumol/L, 95% CI 0.28 to 0.37 mumol/L), age of water service connection to dwelling (predicted blood lead level 0.00087 mumol/L [95% CI 0.00005 to 0.00169 mumol/L] higher per year since service connection) and decreased stature (predicted blood lead level 0.018 mumol/L [95% CI 0.0353 to 0.0015 mumol/L] higher for every standard deviation below the age-specific mean height). CONCLUSIONS: This study found much lower blood lead levels in children than those found in previous Canadian studies. The authors believe that this result is not an artefact due to differences in population sampling or methods of collection of blood specimens. The study showed no clear risk factors for elevated blood lead levels: although a few factors had a statistically significant association with increased blood lead levels, the differences in levels were small and unimportant.

The development and implementation of a revised municipal bylaw to control environmental tobacco smoke.

A bylaw to regulate the contamination of the environment by tobacco smoke was introduced in the Capital Regional District, Victoria, British Columbia as of January 1st, 1991. This smoking control bylaw rigorously limits smoking in all public premises and restricts size, ventilation and location of designated smoking areas. As of January 1st, 1992 all workplaces in this area have become completely smoke-free. This paper describes the process of developing and implementing a municipal smoking control bylaw. Publicity is essential to raise awareness of the issue and to provide information. Engendering of political and public support and the adoption of an appropriate time line for introduction of the bylaw are also important components of the process. Legislation to control tobacco use has been shown to be an effective component of a comprehensive tobacco reduction strategy. Public health officials are urged to consider the implementation of similar policies to combat the health risks posed by environmental tobacco smoke.

Botulism from chopped garlic: delayed recognition of a major outbreak.

Diagnosis of botulism in two teenaged sisters in Montreal led to the identification of 36 previously unrecognized cases of type B botulism in persons who had eaten at a restaurant in Vancouver, British Columbia, during the preceding 6 weeks. A case-control study implicated a new vehicle for botulism, commercial chopped garlic in soybean oil (P less than 10(-4)). Relatively mild and slowly progressive illness, dispersion of patients over at least eight provinces and states in three countries, and a previously unsuspected vehicle had contributed to prolonged misdiagnoses, including myasthenia gravis (six patients), psychiatric disorders (four), stroke (three), and others. Ethnic background influenced severity of illness: 60% of Chinese patients but only 4% of others needed mechanical ventilation (P less than 10(-3]. Trypsinization of serum was needed to show toxemia in one patient. Electromyography results with high-frequency repetitive stimulation corroborated the diagnosis of botulism up to 2 months after onset. Although botulism is a life-threatening disease, misdiagnosis may be common and large outbreaks can escape recognition completely.

Inner-city survey for tuberculosis: evaluation of diagnostic methods.

A total of 1,271 persons living in a socially and economically depressed, inner-city area of Vancouver, British Columbia, voluntarily attended a tuberculosis case-finding campaign. Chest x-ray, on-the-spot specimen of sputum, and tuberculin skin test were offered at the time of the first attendance. All 3 diagnostic methods were found to be well accepted, with 93% of the participants having an x-ray, over 95% producing a sputum specimen, and almost 95% having a tuberculin test (a quarter of these did not, however, report for reading of the test). Eight cases of bacteriologically confirmed pulmonary tuberculosis were found: 6 suspected on x-ray (the remaining 2 films were abnormal but not diagnostic of tuberculosis), and 6 being positive on smear and/or culture of the initial on-the-spot sputum specimen. Examination of a second specimen of sputum diagnosed all of the 8 active cases identified by the survey. These results suggest that, in this particular setting, a chest radiogram taken by a transportable chest x-ray apparatus or examination of 2 sputum specimens might be equally successful at detecting all cases of active pulmonary tuberculosis within the time required for sputum culture. Examination of the sputum smear immediately identifies all the more infectious cases of pulmonary tuberculosis. The prevalence rate of 629 per 100,000 among those presenting themselves to this campaign illustrates the high-yield which might be achieved by active case-finding projects in known high-incidence segments of a generally low-incidence population.