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Energy Source Used (energy + source_used)
Selected AbstractsSurgical Ablation of Atrial Fibrillation: The Columbia Presbyterian ExperienceJOURNAL OF CARDIAC SURGERY, Issue 5 2006Veli K. Topkara M.D. However, it is not widely applied due to its complexity, increased operative times, and the risk of bleeding. Various energy sources have been introduced to simplify the traditional "cut and sew" approach. Methods: This study involves patients undergoing surgical atrial fibrillation ablation (SAFA) at a single institution from 1999 to 2005. Type of concomitant procedures, preoperative clinical characteristics, and chronicity of AF were evaluated in overall patient population. Parameters including surgical approach, lesion pattern, and energy source used were collected intraoperatively. Clinical outcomes examined were postoperative rhythm success, stroke, early mortality, and long-term survival. Results: Three hundred thirty-nine patients were identified. Three hundred twenty-eight (96.8%) patients had associated cardiac disease and underwent concomitant procedures; 75.8% of patients had persistent AF. Energy sources used were microwave (49.8%), radiofrequency (42.2%), and laser (8.0%). In 41.9% of cases a pulmonary vein encircling lesion was the only lesion created. Combination lesion sets were performed in the remaining cases. Rhythm success rates at 3, 6, 12, and 24 months were 74.1%, 68.2%, 74.5%, and 71.1%, respectively. Patients who underwent surgical removal of left atrial appendage by means of stapling or simple excision had no early postoperative stroke. Early mortality was 4.9%. Postoperative survival rates at 1, 3, and 5 years were 89.6%, 83.1%, and 78.0%. Conclusions: Surgical ablation of atrial fibrillation is a safe and effective procedure in restoring sinus rhythm with excellent postoperative survival rates. Further advancements in the field will eventually result in minimally invasive procedures with higher success rates. [source] Greenhouse Gas Profile of a Plastic Material Derived from a Genetically Modified PlantJOURNAL OF INDUSTRIAL ECOLOGY, Issue 3 2000Devdatt Kurdikar Abstract: This article reports an assessment of the global warming potential associated with the life cycle of a biopolymer (poly(hydroxyalkanoate) or PHA) produced in genetically engineered corn developed by Monsanto. The grain corn is harvested in a conventional manner, and the polymer is extracted from the corn stover (i.e., residues such as stalks, leaves and cobs), which would be otherwise left on the field. While corn farming was assessed based on current practice, four different hypothetical PHA production scenarios were tested for the extraction process. Each scenario differed in the energy source used for polymer extraction and compounding, and the results were compared to polyethylene (PE). The first scenario involved burning of the residual biomass (primarily cellulose) remaining after the polymer was extracted from the stover. In the three other scenarios, the use of conventional energy sources of coal, oil, and natural gas were investigated. This study indicates that an integrated system, wherein biomass energy from corn stover provides energy for polymer processing, would result in a better greenhouse gas profile for PHA than for PE. However, plant-based PHA production using fossil fuel sources provides no greenhouse gas advantage over PE, in fact scoring worse than PE. These results are based on a "cradle-to-pellet" modeling as the PHA end-of-life was not quantitatively studied due to complex issues surrounding the actual fate of postconsumer PHA. [source] IS THERE STILL A ROLE FOR THE CLASSICAL COX-MAZE III?ANZ JOURNAL OF SURGERY, Issue 5 2006Cheng-Hon Yap Background: The incidence of surgery for atrial fibrillation (AF) is rising, paralleled by an increase in the types of lesion sets and energy sources used. These alternate energy sources have simplified the surgery at the expense of increased cost of consumables. The classical Cox-Maze III is the gold standard therapy with a proven efficacy in curing AF. Our complete experience with this procedure is presented. Methods: All 28 patients undergoing the classical Cox-Maze III procedure at our institution underwent preoperative assessment and were followed prospectively. Results: Twenty-eight patients underwent the Cox-Maze III procedure between January 2001 and May 2003. Their mean age was 65 years (range, 44,80 years). Twenty-five patients had concomitant cardiac procedures. Mean duration of AF was 8.3 years. Permanent AF was present in 82%. Mean follow-up time was 15 ± 8 months (range, 4,30 months). There were no perioperative or late deaths, or thromboembolic events. Sixty-one per cent had early (<3 months) atrial arrhythmia. Freedom from AF at most recent clinical follow up was 93%. Freedom from late atrial arrhythmia was 82%. Freedom from late AF or atrial flutter by pacemaker interrogation or Holter assessment was 77%. Anti-arrhythmic medication use was reduced. New York Heart Association class improved from an average of 2.8 preoperatively to 1.3 postoperatively. Conclusion: The result of the present study shows the safety and efficacy of the classical Cox-Maze III procedure. With the advantage of proven long-term efficacy, demonstrable safety and avoidance of costly technology, the Cox-Maze III should not be discounted as a treatment option in patients because of its perceived complexity. [source] | ||||||||||