PURPOSE: To compare the clinical efficacy and treatment costs of plastic versus metal biliary stents. MATERIALS AND METHODS: In a randomized trial, 101 patients with malignant common bile duct obstruction underwent transhepatic stent implantation and were followed up until death. Patients were stratified into risk and nonrisk groups. Forty-nine patients received 12-F plastic stents, and 52 received expandable metal stents. Plastic endoprostheses were placed in a two-step procedure; metal stent, in a single procedure. Kaplan-Meier analyses were used to compare patient survival and stent patency rates. RESULTS: The 30-day mortality rate was significantly lower for metal stents (five of 52 [10%]) than plastic stents (12 of 49 [24%]; P = .05). The obstruction rate was 19% (10 of 52; median patency, 272 days) for metal stents and 27% for plastic stents (13 of 49; median patency, 96 days; P < .01). Median time until death or obstruction was longer for metal stents (122 vs 81 days; P < .01). Placement of metal stents was associated with shorter hospital stay (10 vs 21 days; P < .01) and lower cost ($7,542 vs $12,129; P < .01). CONCLUSION: Use of self-expanding metal stents appears to show substantial benefits for patients and to be cost-effective.
PURPOSE: To analyze the influence of computed tomographic (CT) window settings on bronchial wall thickness and to define appropriate window settings for its evaluation. MATERIALS AND METHODS: Three inflation-fixed lungs were scanned with a section thickness of 1.5 mm by using a high-spatial-frequency algorithm. Wall thickness in 10 bronchial specimens was measured with planimetry. Window centers were altered in a range of -200 to -900 HU and window widths in a range of 400-1,500 HU. Relative and absolute differences between CT and planimetric values were calculated. CT and planimetric measures were correlated. Inter- and intraobserver variabilities were determined. RESULTS: Window widths less than 1,000 HU resulted in a substantial overestimation of bronchial wall thickness, whereas widths greater than 1,400 HU resulted in an underestimation of bronchial wall thickness. There was no interaction between "width" and "center" regarding their influence on bronchial walls (F = 0.23; P = .99). Correlation between CT and planimetry was statistically significant (r = .85; P = .0001). Differences between the two observers were not statistically significant; results of the measurements of the two observers correlated well (r = .97; P = .001). CONCLUSION: Bronchial wall thickness on thin-section CT scans should be evaluated with window centers between -250 and -700 HU and with window widths greater than 1,000 HU. Other than window settings, notably window widths less than 1,000 HU, can lead to substantial artificial thickening of bronchial walls.
