Eisner, B. H., Pengune, W. & Stoller, M. L. Use of an antiretropulsion device to prevent stone retropulsion significantly increases the efficiency of pneumatic lithotripsy: an in vitro study. BJU Int. 104, 858-861

Department of Urology, University of California-San Francisco, San Francisco, CA 94143, USA.
BJU International (Impact Factor: 3.53). 03/2009; 104(6):858-61. DOI: 10.1111/j.1464-410X.2009.08540.x
Source: PubMed


To compare the efficiency of pneumatic lithotripsy with and without the Accordion antiretropulsion device (PercSys, Palo Alto, CA, USA).
The study comprised two in vitro experiments: in experiment 1, 10 trials were conducted using stone phantoms (6 x 6 x 10 mm), placed in a horizontal acrylic tube submerged in normal saline. Pneumatic lithotripsy was applied using a Swiss LithoClast (Boston Scientific Corporation, Natick, MA, USA). Each phantom was hit with repeated single firings of the LithoClast until it had travelled 20 cm (control group). The same experiment was then repeated with the Accordion antiretropulsion device positioned proximal to a new stone phantom. In experiment 2, stone phantoms (5 x 5 x 5 mm) were placed in a model ureter made of silicone and submerged in normal saline. Pneumatic lithotripsy was applied continuously on 10 stones for 20 s (200 strikes) without the Accordion device (control group) and on 10 stones with the Accordion device in place (experimental group). The distance of retropulsion was recorded. All stone phantoms were weighed before and after pneumatic lithotripsy.
In both experiments the Accordion group had a significantly greater percentage weight loss than the control group (experiment 1; 11% vs 3%; experiment 2, 53% vs 16%, both P < 0.001).
The Accordion device significantly increased the fragmentation efficiency in both in vitro models. Preventing retropulsion and increasing fragmentation efficiency has the potential to increase the success rate, decrease secondary procedures for migrated stones, and shorten operative times.

1 Follower
10 Reads
  • [Show abstract] [Hide abstract]
    ABSTRACT: Ureteroscopy is the first-line treatment for urinary stone disease at many institutions. Techniques and indications continue to evolve. This Review covers the most current trends, controversies, and issues in ureteroscopic stone management. We present a summary of the most recent evidence regarding ureteroscopic treatment of ureteral and renal stones, current standard indications, adjunct devices and instruments used during ureteroscopy, and future directions.
    No preview · Article · Dec 2009 · Nature Reviews Urology
  • [Show abstract] [Hide abstract]
    ABSTRACT: Ureteroscopic laser lithotripsy is a commonly used technique to treat ureteral calculi.The type of energy source used is one of the main influences of retrograd calculi propulsion. Using a momentum pendulum under-water set-up the induced momentum and the initial velocity were investigated. Pulsed laser light from three different clinically available laser systems, including a Ho:YAG laser, a frequency-doubled double-pulse (second harmonic generation, SHG) Nd:YAG laser and a flash-lamp pumped dye (FLPD) laser, were transmitted via flexible fibres of different core diameter to the front of the pendulum sinker. Single pulses at variable pulse energy, according to the clinical laser parameter settings, were applied to the target sinker, thus causing a repulsion-induced deflection which was documented by video recording. The maximum deflection was determined. Solving the differential equation of a pendulum gives the initial velocity, the laser-induced momentum and the efficiency of momentum transfer. The induced deflection as well as the starting velocity of the two short-duration pulsed laser systems (SHG Nd:YAG, FLPD) were similar (s max = 2–3.6 cm and v 0 = 150–200 mm/s, respectively), whereas both values were lower using the Ho:YAG laser with a long pulse duration (s max = 0.9-–1.6 cm and v 0 = 60–105 mm/s, respectively). The momentum I induced by the Ho:YAG laser was only 50% and its transfer efficacy η Repuls was reduced to less than 5% of the values of the two short-pulsed laser systems. This investigation clearly showed the variable parts and amounts of repulsion using different pulsed lasers in an objective and reproducible manner. The momentum transfer efficiency could be determined without any physical friction problems. Further investigations are needed to compare stone fragmentation techniques with respect to laser repulsion and its clinical impact.
    No preview · Article · Oct 2011 · Lasers in Medical Science
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Endoscopic lithotripsy is often prolonged secondary to the retrograde migration of calculous fragments. Various balloons, baskets, and other devices have been used to prevent this migration. Our purpose is to analyze the effect of the Accordion(®) on stone migration and overall efficiency during lithotripsy. We prospectively evaluated 21 patients with a total of 23 distal ureteral stones. Patients underwent lithotripsy using an endoscopic impact lithotriptor. The Accordion was randomly used in 11 of these 21 patients. Data were collected regarding stone migration, stone size, stone ablation, ureteral clearing, and lengths of time for various stages of each procedure. Patients who were treated with the Accordion device experienced significantly less retrograde migration during fragmentation (P=0.0064). When stone volume was taken into account (but not on a per stone basis), ablation and ureteral clearing were also expedited, and fewer lithotripter "hits" and basket "sweeps" were needed. The Accordion device is effective in preventing the migration of stone fragments during endoscopic ureteral lithotripsy. Our data suggest that this device may also increase efficiency of the fragmentation and clearance of ureteral calculi.
    Full-text · Article · Dec 2011 · Journal of endourology / Endourological Society
Show more