PURPOSE: Some patients fitted with an AMS800®-type artificial urinary sphincter report urinary leaks in the sitting position, which mechanism remains unclear.
This experimental study tries to explain these residual leaks by characterizing fluid transfers and pressure variations within the device during cuff compression.
MATERIALS AND METHODS: Two complete sets of AMS800® devices were tested on an original test bench. First, a qualitative study, using methylene blue dye, was performed to assess fluid transfer within the device during manual cuff compression. Then, after estimating the pressures exerted on the perineal floor in the sitting position, pressure variations within the different AMS800® components were measured in real time, using the pressure sensors of an urodynamic workstation.
RESULTS: When the AMS800® cuff is compressed between two fingers, we can observe a reflux of the blue dye into the balloon through the pump resistor. After compressing the cuff during 5, 10, 15 and 20 seconds at a pressure of 150 cmH2O, the minimal pressure measurements in the cuff were of 37, 25, 14 and 12 cmH2O respectively. Furthermore, the time required for cuff re-pressurization was 68, 87, 101 and 117 seconds.
CONCLUSIONS: Urinary leaks reported in sitting position by patients fitted with an AMS800® device may be explained by compression of the urethral cuff between the pelvic floor and the chair, which causes emptying of the cuff into the balloon. Patients could be reassured that there is no implant dysfunction and adopt simple lifestyle strategies to circumvent these leaks.
Written by:
Beaugerie A, Phé V, Munbauhal G, Chartier-Kastler E, Mozer P. Are you the author?
Department of Urology, Pitié-Salpétrière academic hospital, Pierre et Marie Curie University (Paris VI), Paris, France; Institut des Systèmes Intelligents et de Robotique (ISIR), équipe AGATHE, Pierre et Marie Curie University (Paris VI), Paris, France.
Reference: J Urol. 2014 Mar 3. pii: S0022-5347(14)02826-2.
doi: 10.1016/j.juro.2014.02.2567
PubMed Abstract
PMID: 24603107
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