The effects of high field strength MRI on electrodes and pulse generator in dynamic graciloplasty.
OBJECTIVE
Dynamic graciloplasty is a treatment for intractable faecal incontinence. A gracilis muscle is transposed around the anus and stimulated with an implanted pulse generator (IPG). This in vitro study was designed to determine the safety of MRI in patients with implanted electrodes and pulse generators for dynamic graciloplasty.


METHODS
Temperatures were measured with fiberoptic probes around the devices in a cadaver model. Current was measured with an oscilloscope connected to electrodes and IPG. Movement and IPG parameter setting were observed before, during and after testing.


RESULTS
Minor temperature increase under 1 degrees C were observed around the electrodes. Amplitudes measured were within the range of -1 and +1 Volt. No movement or changing of IPG parameters was noted.


CONCLUSIONS
Changes noted are well within physiological ranges. Dynamic graciloplasty is not a contraindication for high field strength MRI.
Department of Surgery, University Hospital Maastricht, the Netherlands. m.rongen@ah.unimaas.nl
M-J G M
MJ
Rongen
R G H
RG
Beets-Tan
W H
WH
Backes
C G M I
CG
Baeten
D002102:Cadaver; D004599:Electric Stimulation Therapy / Q000295:instrumentation*; D004567:Electrodes, Implanted; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005240:Feasibility Studies; D005242:Fecal Incontinence / Q000601:surgery; D006358:Hot Temperature / Q000009:adverse effects; D006801:Humans; D008279:Magnetic Resonance Imaging; D018482:Muscle, Skeletal / Q000601:surgery; D013514:Surgical Procedures, Operative / Q000379:methods*