陳偉權  張志宏  陳建旭  劉文欽  楊儀華

天主教聖功醫院 泌尿外科

Wei-Chuan Chen, Chih-Hung Chang, Jian Shiu Chen, Wen-Chin Liou,

 Yi-Hua Yang

Division of Urology Department of Surgery St. Joseph Hospital, Kaohsiung;

 

Purpose: Because trapped air pockets in the interface coupling of extracorporeal shock wave lithotripsy (ESWL) plays a key role, this study used semi-liquid gel and solid conducting pad as interface of ESWL to compare the difference of air pockets content when they were used during ESWL.

Materials and Methods: Materials and Methods: A Dornier compact delta-2 RC lithotriptor was used in this experiment. Since this model was equipped with a built-in photographic system within the shock wave head, the air pockets content of the interface between the head and the patient body could be observed. The coupling gel was made of four different conducting materials, the first being a semi-liquid gel and the second a water-borne solid bio-gel pad with a diameter of 150 mm and a thickness 3 mm circular conductive gasket, the third for the sticky polymer solid chemical gel pad, diameter 150 mm thickness of 3 mm circular conductive gasket. The fourth is a composite glue pad of solid chemical gel pad with onlay of solid biogel pad, a circular conductive gel pad with a diameter of 150 mm and a thickness of 6 mm. Experiments divided into four gasket groups. The first group: the use of traditional semi-liquid as a conductive medium, the second group: the use of water-borne solid bio-gelpad, the third group: the use of sticky polymer solid-state chemical gelpad, the fourth group: the use of solid-state bio-adhesive chemical gelpad onlayed by release of water-born bio-gelpad, each group of experiments were repeated three times. In addition to comparing the trapped air pockets content between the patient body and the different coupling materials in each group, comparison of the air pockets content after the shock wave head slid on the body surface was also performed

Results：The highest close-fitting and the highest adhesion were obtained by using the water-release solid bio-gel (group 2) and the stacked gelpad (group 4), which was covered with the adhesive solid polymer gelpad, in which group air pockets content is almost invisible. Followed by the use of sticky polymer solid chemical gelpad (the third group). Air pockets was the most using traditional semi-liquid gel(the first group). Besieds, the addition of liquid gel sprayed on the surface of gel pad did not further decreased the air pockets. The fixation effect was best in stacked gelpad (group 4), but did not change even after the body sliding

Conclusions: The results of this experiment show that the air pockets content of the interface gasket was significantly less than that of the traditional commercial gel by using the water-releasing solid bio-adhesive and the polymer solid-state chemical stacked gasket, besides the favorable shock wave transmission and increasing stone disintegration rate. The new stacked gasket can be inferred to replace the traditional commercially available gel, providing future clinical use.