Objective: A new combination intracorporeal lithotripter
(CQS-01) has been developed that incorporates the beneficial
effects of pneumatic lithotripsy and ultrasound lithotripsy.
An in vitro study was performed to assess the efficiency of
stone fragmentation and clearance of this new intracorporeal
ultrasound lithotripter compared with currently available
ultrasound units (EMS-III/IV).
Methods: Twenty phantom stones made of dental gypsum
were randomly divided into four groups, CQS-01 ultrasound
lithotripter (70% power and 70% duty factor), EMS-III
ultrasound lithotripter (70% power and 70% duty factor),
EMS-IV ultrasound lithotripter (type A, 70% power and 70%
duty factor) and EMS-IV ultrasound lithotripter (type B,
70% power and 100% duty factor) were used to fragment and
remove phantom stones. The mean stone breakdown times
and fragment removal times and stone fragment sizes for the
standard ultrasound devices were compared to determine the
completeness and efficiency of stone fragmentation and removal.
Results: The average time for stone breakdown was 7.4±1.7 s,
9.4±1.5 s, 82.2±12.6 s and 51.4±18.7 s, respectively, there was
no significance between CQS-01 and EMS-III (P>0.05), but
there was significance between CQS-01, EMS-III and EMS-IV (A
and B); The average time for stone clearance using the ultrasound
devices was 387.8±60.9 s, 411.6±51.5 s, 568±119.1 s and
383.6±75.6 s, respectively. The ultrasound units of CQS-I, EMSIII
and EMS-IV(B) was efficient as same as (P>0.05), but there
was significance between EMS-IV(A) and EMS-IV(B) (P<0.05). In addition, the average size of the largest fragments removed
was the same (<3 mm).
Conclusions: The ultrasound capabilities in a newly developed
lithotrite (CQS-01) exhibited the same ability to fragment
and clear phantom stones compared with standard ultrasound
devices alone. These preliminary studies suggest that this
combination pneumatic/ultrasound lithotripter may be an ideal
device for the expeditious removal of large-volume renal or
bladder calculi. Additional studies are warranted to better assess
the capabilities of this new device in treating humanstones of
various compositions and its safety, as well as the optimal power
and frequency settings.