Monga Manoj, Hendlin Kari, Skenazy Jason, Ramani Anup
Department of Urologic Surgery, University of Minnesota Medical School and the VAHCS Minneapolis, Minneapolis, Minnesota 55455, USA.
Urology. 2004 Nov;64(5):892-4. doi: 10.1016/j.urology.2004.06.026.
To compare irrigant flow characteristics through standard working channels (3.6F to 4.5F) and a dual-diameter working channel. Irrigant flow is critical for adequate visualization during endoscopic procedures.
Working channels were created out of 80 cm of light wall polytetrafluoroethylene (PTFE) tubing (inner diameter 3.6F, 4.0F, and 4.5F) with a male Luer connector attached to one end by epoxy resin. The dual-diameter working channel was created with a 70-cm segment of PTFE (4.5F inner diameter, 0.059 in.) and a 10-cm segment of PTFE (3.6F inner diameter, 0.047 in.) with a male Luer connector attached to the free end of the 4.5F tubing. Stone basket shafts (100 cm in length, outer diameter 1.9F, 2.4F, and 3.0F) were created out of unmodified polyimide tubing with a 0.018-in.-diameter nitinol mandrel epoxy core for stability. Irrigant flow was measured at 100 mm Hg pressure for 1 minute with an empty channel and with stone basket shafts in the channel.
The flow rates were significantly greater with the dual-diameter working channel than with the standard flexible ureteroscope (3.6F) working channel using an empty channel (79.2 versus 44.1 mL/min, P = 0.0001), 1.9F basket (35.9 versus 10.0 mL/min, P = 0.003), 2.4F basket (20.7 versus 4.3 mL/min, P = 0.002), and 3.0F basket (6.0 versus 0.7 mL/min, P = 0.0002) sheath.
A dual-diameter working channel may optimize irrigant flow characteristics for flexible ureteroscopes while maintaining a small distal tip diameter.
比较冲洗液通过标准工作通道（3.6F至4.5F）和双直径工作通道的流动特性。冲洗液流动对于内镜手术期间的充分可视化至关重要。
用80厘米的薄壁聚四氟乙烯（PTFE）管（内径3.6F、4.0F和4.5F）制作工作通道，一端通过环氧树脂连接一个公鲁尔接头。双直径工作通道由一段70厘米的PTFE（内径4.5F，0.059英寸）和一段10厘米的PTFE（内径3.6F，0.047英寸）制成，公鲁尔接头连接到4.5F管的自由端。用未改性的聚酰亚胺管制作结石篮轴（长度100厘米，外径1.9F、2.4F和3.0F），内部有一个直径0.018英寸的镍钛诺芯棒环氧树脂芯以保持稳定性。在通道为空和通道中有结石篮轴的情况下，在100毫米汞柱压力下测量冲洗液流动1分钟。
使用空通道时，双直径工作通道的流速显著高于标准软性输尿管镜（3.6F）工作通道（79.2对44.1毫升/分钟，P = 0.0001）；使用1.9F篮时（35.9对10.0毫升/分钟，P = 0.003）；使用2.4F篮时（20.7对4.3毫升/分钟，P = 0.002）；使用3.0F篮时（6.0对0.7毫升/分钟，P = 0.0002）。
双直径工作通道可优化软性输尿管镜的冲洗液流动特性，同时保持较小的远端尖端直径。
