Twenty years of single center experience in ESWL 1987-2007: an evaluation of 3079 patients

Since 1987 we have consecutively operated five different Dornier lithotriptors in the management of lithiasis at all levels of the urinary tract. At the time of usage of each machine we periodically evaluated the treatment results in order to eventually adapt treatment strategies to improve results. None of these evaluations comprised the totality of patients treated on a certain machine during the entire period it was in use. This overview retrospectively compares the results over the entire period in order to gauge the impact of the different machines and SW-sources on clinical results.

A total of 3079 patients, treated from september 1987 till september 2006 with two electrohydraulic machines, HM4 (1987-1988) and MPL9000 (1988-1994), and three electromagnetic machines, Compact (1991-1999), DoLi U/50 (1996-1999) and DoLi S (1999-2006) were thus evaluated. Parameters reviewed were stone location and size, retreatment rate, auxiliary procedures, stone free rate and Effectiveness Quotient (EQ).

There is no significant difference in stone size or stone free rate (p=0.4715) for the different groups. There is a significant difference for auxiliary procedure rate and retreatment rate for the different machines. The DoLiS with EMSE 220F-XXP scores significantly better than any of the other systems for auxiliary procedure rate pre-ESWL (p<0.05) and total auxiliary procedure rate (p<0.05), and retreatment rate (p=0.0024). There is a gradual increase in EQ with the consecutive machines.

Although stone free rates (85%-88.8%) remained constant, Effectiveness Quotients improved. This is largely due to reduced auxiliary procedure rates and reduced retreatment rates. The first effect is a consequence of improvement in treatment strategies and experience, the latter no doubt also of improvement in SW-sources.