Objective To evaluate the efficiency of percutaneous balloon angioplasty of coarctation ot the aorta in children and discuss its risk factors that can lead to poor long-term results. Mehods From September 1987 to Augu...Objective To evaluate the efficiency of percutaneous balloon angioplasty of coarctation ot the aorta in children and discuss its risk factors that can lead to poor long-term results. Mehods From September 1987 to August 1999, 24 patients underwent 27 balloon angioplasty procedures for native or recurrent coarctation of the aorta at our institution. There were 19 patients with discrete (membranous) coarctation, 4 patients with long-segment and aortic arch hypoplasia, and 1 patient with postoperative recurrence. The balloon diameter was chosen not to exceed the diameter of the aorta proximal to the stenotic site ( 11.06 + 2.80 mm vs 11.78 + 3.18 mm), with the chosen diameter two to four times that of the stenotic segment (2.57 + 0.68 times). The patients have been followed up for half to twelve years (mean 6.2 + 2.8 years). Satisfactory result was defined as a reduction in the pressure gradient across the site of coarctation to ≤20 mm Hg.Results The systolic pressure gradient across the coarctation site decreased from 48.17 + 14.68 mm Hg to 14.96 + 13.12 mm Hg ( P ＜ 0.01 ) and the diameter of the coarctation site increased from 4.66 + 2.43 mm to 8.80 + 3.32 mm ( P ＜ 0.01 ). Immediate satisfactory results were obtained in 19 patients (79％). Of the 5 patients with unsatisfactory results, 4 had aortic arch hypoplasia and 1 had membranous coarctation. Of the 19 patients with satisfactory results, 18 patients had membranous coarctation and 1 patient had recurrent postoperative coarctation. No aneurysm and other complications had occurred in any patients at the follow-ups.Conclusion Percutaneous balloon angioplasty is an effective treatment altemative to surgery in most patients with recurrent postoperative or native membranous coarctation of the aorta. It should not be recommended for the coarctation of aortic arch hypoplasia.展开更多
A single-/dual-wavelength switchable and tunable erbium-doped fiber laser(EDFL) with super-narrow linewidth has been proposed and experimentally demonstrated at room temperature. The fiber laser is based on a compound...A single-/dual-wavelength switchable and tunable erbium-doped fiber laser(EDFL) with super-narrow linewidth has been proposed and experimentally demonstrated at room temperature. The fiber laser is based on a compound cavity simply composed of a ring main cavity and a two-ring subring cavity(TR-SC). Regardless of single- or dual-wavelength operation, the EDFL could always work well in single-longitudinal-mode(SLM) state at every oscillating wavelength. In dual-wavelength operation, the spacing could be tuned from 0 nm to 4.83 nm. In single-wavelength operation, the EDFL could lase at a fixed wavelength of 1 543.65 nm or another wavelength with a tunable range of 4.83 nm. The super-narrow linewidths of 550 Hz and 600 Hz for two wavelengths are obtained. The proposed EDFL has potential applications in microwave/terahertz-wave generation and high-precision distributed fiber optical sensing.展开更多
文摘Objective To evaluate the efficiency of percutaneous balloon angioplasty of coarctation ot the aorta in children and discuss its risk factors that can lead to poor long-term results. Mehods From September 1987 to August 1999, 24 patients underwent 27 balloon angioplasty procedures for native or recurrent coarctation of the aorta at our institution. There were 19 patients with discrete (membranous) coarctation, 4 patients with long-segment and aortic arch hypoplasia, and 1 patient with postoperative recurrence. The balloon diameter was chosen not to exceed the diameter of the aorta proximal to the stenotic site ( 11.06 + 2.80 mm vs 11.78 + 3.18 mm), with the chosen diameter two to four times that of the stenotic segment (2.57 + 0.68 times). The patients have been followed up for half to twelve years (mean 6.2 + 2.8 years). Satisfactory result was defined as a reduction in the pressure gradient across the site of coarctation to ≤20 mm Hg.Results The systolic pressure gradient across the coarctation site decreased from 48.17 + 14.68 mm Hg to 14.96 + 13.12 mm Hg ( P ＜ 0.01 ) and the diameter of the coarctation site increased from 4.66 + 2.43 mm to 8.80 + 3.32 mm ( P ＜ 0.01 ). Immediate satisfactory results were obtained in 19 patients (79％). Of the 5 patients with unsatisfactory results, 4 had aortic arch hypoplasia and 1 had membranous coarctation. Of the 19 patients with satisfactory results, 18 patients had membranous coarctation and 1 patient had recurrent postoperative coarctation. No aneurysm and other complications had occurred in any patients at the follow-ups.Conclusion Percutaneous balloon angioplasty is an effective treatment altemative to surgery in most patients with recurrent postoperative or native membranous coarctation of the aorta. It should not be recommended for the coarctation of aortic arch hypoplasia.
基金supported by the Youth Foundation of Hebei Educational Committee(No.QN2015235)the Technology Foundation for Selected Overseas Chinese Scholar of Ministry of Human Resources and Social Security of China(No.CG2015003006)the Special Funding of Comprehensive Capability Enhancement Program from Hebei University
文摘A single-/dual-wavelength switchable and tunable erbium-doped fiber laser(EDFL) with super-narrow linewidth has been proposed and experimentally demonstrated at room temperature. The fiber laser is based on a compound cavity simply composed of a ring main cavity and a two-ring subring cavity(TR-SC). Regardless of single- or dual-wavelength operation, the EDFL could always work well in single-longitudinal-mode(SLM) state at every oscillating wavelength. In dual-wavelength operation, the spacing could be tuned from 0 nm to 4.83 nm. In single-wavelength operation, the EDFL could lase at a fixed wavelength of 1 543.65 nm or another wavelength with a tunable range of 4.83 nm. The super-narrow linewidths of 550 Hz and 600 Hz for two wavelengths are obtained. The proposed EDFL has potential applications in microwave/terahertz-wave generation and high-precision distributed fiber optical sensing.
