Sacral magnetic stimulation in paradoxical puborectalis syndrome

Our earlier studies have demonstrated that sacral magnetic stimulation (MS) in the canine model, in healthy volunteers and in constipated subjects brought about a rise in rectal pressure and a decline in rectal neck (anal canal) pressure as well as rectal evacuation. Based on these results, we studied the effect of sacral MS on defecation in patients with paradoxical puborectalis syndrome (PPS).

Eleven subjects (8 women, 3 men; age 36-53 years) with PPS were enrolled in the study. The magnetic coil was placed on the back with its center located between L4 and L5. Stimulation parameters were set at 70% of maximum intensity, 40 Hz frequency and 2 s burst length with 2 s off. During MS, the rectal neck and gastric (intra-abdominal) pressures were measured. The procedure was performed in the empty and the full rectum using the balloon expulsion test in the latter.

MS of the empty and balloon-filled rectum brought about a rise in the rectal pressure (p < 0.001), decline in rectal neck pressure (p < 0. 001) and no significant change in intragastric pressure (p > 0.05). The balloon was expelled by all patients.

Sacral MS succeeded in expelling the water-filled rectal balloon. The method is simple, easy, noninvasive, nonradiologic and can be performed on an outpatient basis in the treatment of PPS.