Air Pockets Trapped During Routine Coupling In Dry Head Lithotripsy Can Significantly Decrease The Delivery Of Shock Wave Energy
Like fine espresso, successful lithotripsy is dependent upon the machine, the water, the generating substance (be it bean or beam), and the "barista".
In this very important study the authors show that variations in coupling efficiency between the shock head and the patient can greatly decrease the propagation of effective shock waves. While the initial contact between patient and shock head is important, the repositioning of the patient during treatment can have the most damaging impact on shock wave lithotripsy's effectiveness.As little as 2% coverage of the shock head by air pockets resulted in a drop in stone fragmentation of 20-40%. This could well explain why the second and third generation, bathless lithotriptors failed to equal, let alone exceed, the original data obtained with the Dornier HM-3 bath dependent technology.It is of interest that rather than developing a lithotriptor that is more user friendly, the current machines require more skill and attention to detail in order to achieve the desired result.Bottom line: if you must reposition the patient during a procedure, you should go through the entire coupling procedure as though you were beginning the procedure anew.(Source: Journal of Urology : February 2007.)