Development of a new sialendoscopic sialolithectomy system using a shape-memory alloy

本研究的目的是开发一种适合于形状记忆合金实际使用的新型非手术内窥镜胆囊切除术系统，并将其应用于临床。我们与日本acment株式会社合作开发了一款使用镍钛诺的篮子钳，镍钛诺是一种镍钛超弹性形状记忆合金。它有三根直径0.16毫米的镍钛诺线，记住了足够的形状来捕捉帆石。但篮式钳外径0.78mm，直径太大，无法插入咽镜工作通道。因此，我们应该改进筐式钳，使其外径比现在的更小、更小。我们还开发了两种精细的涎内窥镜，可以通过舌下管的开口进入下颌下管。一种是外径1.1毫米的唾液内窥镜（POLYDLAGNOST GmbH，德国），有6000像素的光纤，它有一个插入篮子钳的工作通道和一个灌溉通道。同时，我们开发了一种外径小于0.4mm的超细篮式鼻内窥镜专用钳，可插入工作通道。另一种是外径1.2 mm的鼻内窥镜（日本FiberTech Co., Ltd.），使用1600像素的光纤和0.75内径的工作通道，其中可插入1.9F的篮筐钳（美国波士顿科学公司）。使用这些新开发的唾液内窥镜系统，我们成功地切除了两名患者的颌下腺唾液石。然而，我们的系统存在问题；我们的系统不能去除直径大于唾液管直径的唾液石。我们认为我们需要开发一种鼻内镜碎石系统，以确保去除各种大小的风石。

The purpose of this study was to develop a new non-surgical endoscopic sailolithectomy system suitable for practical use with a shape-memory alloy and to apply it to the clinical use.We developed a basket forceps with the collaboration of ACTMENT Co. Ltd. (Japan) using nitinol, which is a superelastic shape-memory alloy of nickel and titanium. It has three nitinol wires of 0.16mm diameter memorized an adequate shape to catch the sailolith. However, the outer-diameter of basket forceps is 0.78mm, and the diameter is too large to insert the working channel of the sialendoscopy. Therefore, we should improve the basket forceps to reduce the outer diameter smaller and smaller than the present one in the future.We also developed two types of fine sialendoscope, which could be introduced to the submandibular duct through the opening of sublingual caruncula. One is a sialendoscope of 1.1-mm outer-diameter (POLYDLAGNOST GmbH, Germany) with 6000-pixels optic fibers, and it has a working channel to insert a basket forceps and an irrigation channel. At the same time, we developed an ultrafine basket forceps specialized in the sialendoscope with less than 0.4mm outer-diameter, which can be inserted into the working channel. The other is a sialendoscope of 1.2-mm outer-diameter (FiberTech Co., Ltd., Japan) with 1600-pixels optic fibers and a working channel of 0.75 inner-diameter, in which a 1.9F basket forceps (Boston Scientific Corporation, USA) can be inserted.Using these newly developed sialendoscopy systems, we successfully removed sialoliths of the submandibular gland of two patients. However, our systems have the problem ; our systems do not enable to remove the sialolith with the larger diameter rather than the diameter of the salivary duct. We consider that we need to develop a sialendoscopic lithotripsy system to ensure the removal of various size of sailolith.