Portal de Periódicos da CAPES

Poster 5: The Pudendal Nerve Mediates the Reflex Contraction Caused by Anal Canal Catheter Movement

2005; Lippincott Williams & Wilkins; Volume: 11; Issue: Supplement 1 Linguagem: Inglês

10.1097/01.spv.0000178860.90237.39

1542-5991

Noelani M. Guaderrama, J Liu, Charles W. Nager, Dolores H. Pretorius, G. Sheean, Ravinder K. Mittal,

Anorectal Disease Treatments and Outcomes

OBJECTIVE: Movement of a catheter in the anal canal induces reflex contraction of the anal sphincter. We studied the effects of catheter movement in the anal canal on the electromyography (EMG) activity of the external anal sphincter (EAS) and puborectalis muscle (PRM) before and after pudendal nerve block (PNB). METHODS: Eleven nulliparous women were studied using side-hole manometry and simultaneous EMG. Station pullthrough (SPT) and rapid pullthrough (RPT) techniques were used to measure anal canal pressures.Recordings were made at rest and during a voluntary squeeze. The EMG of the EAS and PRM were recorded in arbitrary units (au) using bipolar needle electrodes placed in the respective muscles. PNB was performed transvaginally with 10 cc of 1% lidocaine on each side. Manometry was repeated after PNB. RESULTS: Before PNB, peak resting anal canal pressure is significantly higher during RPT as compared with the SPT technique. EMG recordings revealed a reflex contraction of the EAS and PRM during RPT at rest. After PNB, there is no difference in the peak anal canal pressure between SPT and RPT techniques. There was no reflexive increase in EMG activity of the EAS or PRM muscles during resting RPT. Squeeze-related EMG activity of the EAS and PRM and anal canal pressures are also reduced significantly by the PNB. CONCLUSIONS: Movement of a catheter in the anal canal induces a pudendal nerve-mediated reflex contraction of the EAS and PRM.FIGURE 1