Development of Destruction System for Renal, Ureteral and Biliary Calculi using Pin-hammer Microexplosion

爆炸过程中有两种作用：冲击波能量产生的动态作用和爆炸产生的气体能量产生的静态作用。研制了一种以动力作用为主的体外循环导管。应用该导管行微爆碎石术131例，成功率100%。微爆碎石术是目前膀胱结石最好的治疗方法。但爆炸导管因产生有害气体，不能用于治疗输尿管、肾、胆管结石。为了解决这一问题，我们新开发了两种类型的碎石机：针击式碎石机和胶囊碎石机。这些碎石机的引爆威力被激发出来。因此，针锤碎石机是合适的。三毫克三硝基间苯二酚用于炸药。炸药、点火系统和销钉锤装在一个直径2.6毫米、长31毫米的不锈钢圆柱形药室内。通过爆破，直径1.3 mm的针锤被产生的气体以120m/s的初始速度从药室推出，并被控制在距离药室尖端5 mm处不溢出。输尿管和胆管结石抗压强度均在65 kg/cm2以下，属于低强度组。用该碎石机对直径13 mm以内的结石进行碎石。输尿管的抗张强度与胆囊壁和胆管的抗拉强度相当。这些材料适用于微爆炸。预期的输尿管针锤损伤在3天内痊愈。应用钉锤微爆碎石术治疗输尿管、肾结石48例，成功率65%。在未来，我们将努力提高成功率，消灭胆管结石。

There are two kinds of action in explosion; dynamic action due to the energy of shock wave and static action due to the energy of gas generated in detonation. An exploseve catheter mainly using dynamic action was developed. Up to date microexplosion cystolithotripsy using this catheter was performed in 131 cases with a success rate of 100 %. At present microexplosion lithotripsy is the best method for bladder calculi removal. However, the explosive catheter could not be applied to the destruction of ureteral, renal and biliary calculi, because of harmful gas generation. For the settlement of that reason, we newly developed two types of lithotriptor; a pin-hammer and capsule type. A detonation power of these lithotriptors was exanimed. As the result, a pin-hammer lithotriptor was suitable. Three mg trinitroresorcinate is used for explosive. The explosives, an ignition system and a pin-hammer are loaded inside a stainless steel cylindrical chamber 2.6 mm in diameter and 31 mm length. By blasting, the pin-hammer, with a diameter of 1.3 mm, is pushed out from the chamber at a initial velocity of 120 m/sec by generated gas and is controlled not to overrun at a distance of 5 mm from the tip of the chamber. The compressive strength of ureteral and biliary calculi was below 65 kg/cm^2 and belonged to the low strength group. These calculi within 13 mm in diameter were destructed using this lithotriptor. The tensile strength of ureter was alomost equal to gall bladder and bile duct. These materials were suitable in microexplosion. Expected ureteral injury by the pin-hammer was cured within 3days. The application of pin-hammer microexplosion was in 48 patients with ureteral and renal calculi, with a success rate of 65 %. In future we will make efforts to improve a success rate and to destruct biliary calculi.