膨張破砕剤による尿路結石破砕の基礎的研究

Abstract

尿路結石症の非観血的治療法において, 大きな結石を砕石し摘出するために, 膨張破砕剤による尿路結石破砕の基礎的研究を施行した.1)膨張破砕剤の発生する膨張圧による推定結石破砕時間は, 20, 30, 40 mmの結石で7.5, 9, 11分であり, 十分臨床応用可能であると思われた.2) 55×54×33 mmのヒト膀胱結石は24分で2分割された.3)種々の大きさのモデル結石を使用したモデル結石破砕実験において, 穿孔すべて至適孔長は結石の直径が20 mm以下の場合は直径の2分の1程度の短い穿孔でよく, 結石の直径が30 mm以上の場合は直径の4分の3以上の長い穿孔が必要であると思われた.4)使用後の膨張破砕剤用カテーテルには破損がなく, アルカリ性溶媒の漏出も認められなかった.5) 500 ml/hr以上の速度で生理食塩水を灌流しながら手術を施行すれば, 膨張破砕剤用カテーテルが破損したとしても膀胱粘膜および腎盂粘膜にまったく影響は認められなかった

The application of expansive splitter for industrial use to lithotripsy was studied. A natural rubber latex catheter 350 mm in length, 3.5 mm in diameter and 0.1 mm in thickness was newly developed for prevention from alkalization by expansive splitter. Expansive pressure generated by expansive splitter was measured to calculate the fragmentation time of urinary stones. Urinary stones 20, 30 or 40 mm in diameter were expected to be fragmented in 7.5, 9 and 11 minutes. Human bladder stone 55 x 54 x 33 mm in size was divided into two parts in 24 minutes using expansive splitter. The fragmentation test of model calculi was performed to decide the boring length necessary for the fragmentation of urinary stones. The necessary boring length was a half of the stone diameter in stones smaller than 20 mm in diameter and was 3/4 of it in stones larger than 30 mm in diameter. A tolerance test of the catheter was performed. When the used catheters for splitting were immersed in water, no change was observed in pH, in spite of the elevation of pH from 6.6 to 12.3 when the splitter itself was immersed in water. No leakage of water from the catheter was observed in this tolerance test. Histological change on the epithelium of the bladder and the renal pelvis by expansive splitter was examined. The mucosa of the dog; bladder and the pig renal pelvis, to which expansive splitter was made contact, showed no histological change after 30, 45 or 60 minutes after the contact. In conclusion, expansive splitter enclosed in the natural rubber latex catheter can be employed for clinical use to fragment urinary calculi in endourological procedures.