Telemetric monitoring of bladder function in female Göttingen minipigs.

Abstract

To generate real-time radio-telemetric urodynamic reference data of maximum detrusor pressure (Pdetmax ), maximum flow rate (Qmax) and estimated grade of infravesical obstruction, as well as duration of detrusor contraction (DOC), in female Göttingen minipigs and to describe translational aspects of the use of Göttingen minipigs for urological research. A telemetric transmitter was implanted into five female Göttingen minipigs, and 24h measurements in metabolic cages were taken. Through operator-based analysis, synchronized real-time radio-telemetric cystometric data with flowmetric data and video sequences were used to determine voiding detrusor contractions (VCs) and non-voiding detrusor contractions (NVCs). Furthermore, data from telemetric natural-filling cystometry from free-moving and restricted maintenance conditions were compared for potential differences. The median (range) Pdetmax of VCs was 120.6 (21.0-370.0) cmH2 O and, therefore, significantly different from that of NVCs (64.60 [20.4-280.6 cmH2 O] cm H2 O). Intraindividual comparison of minipig data revealed great differences in voiding contractions. The effects of limited movement on VCs were analysed and showed significantly higher Pdetmax and lower DOC than in free-moving conditions. The presented data can be used for the development of telecystometric implanted minipig models, to investigate changes of detrusor function such as under- or overactivity, and might serve as model for bladder changes occurring with iatrogenic bladder outlet obstruction (BOO) or different therapeutic options for overactive bladder. Radio-telemetric real-time natural filling and voiding cystometries are feasible, reproducible in non-anaesthetized minipigs with free or limited movement and can give new insights into circadian behaviour and physiological and pathological bladder function.