Comparison of Sacral Nerve Modulation and Pudendal Nerve Stimulation in Treatment of Fecal Incontinence

• Wexner Score (Jorge 1993) [ Time Frame: 7, 14 days, 3, 6 & 12 months ] [ Designated as safety issue: No ]
• Incidence of surgical complications (adverse events) graded according to Dindo (2004) [ Time Frame: 30 days ] [ Designated as safety issue: Yes ]
• Quality of Life (FIQL (Rockwood 2000)) [ Time Frame: 14 days, 3, 6 & 12 months ] [ Designated as safety issue: No ]

• Wexner Score (Jorge 1993) [ Time Frame: 7, 14 days, 3, 6 & 12 months ] [ Designated as safety issue: No ]
• Incidence of surgical complications (adverse events) graded according to Dindo (2004) [ Time Frame: 30 days ] [ Designated as safety issue: Yes ]
• Quality of Life (SF36v2, FIQL (Rockwood 2000)) [ Time Frame: 14 days, 3, 6 & 12 months ] [ Designated as safety issue: No ]

Sacral nerve modulation (SNM) is an established treatment for refractory lower urinary tract and bowel dysfunction (Spinelli 2008). Pudendal nerve stimulation (PNS) has been proposed for patients failing SNM treatment of urinary dysfunction (Spinelli 2005). In this study SNM and PNS are compared for the treatment of fecal incontinence. In a test phase, both treatments will be applied for one week each in a randomized and blinded order (cross-over design). After the test phase the more successful treatment will be determined and applied permanently. If both treatments are equally sufficient, PNS will be chosen for permanent stimulation, since preliminary data indicate that PNS has a lower power consumption than SNM. Lower power consumption results in a longer lifetime of the stimulator, thus requiring less replacement surgeries.

Primary Surgery:

• Implantation of two electrodes, one placed next to the sacral nerve, one close to the pudendal nerve. Electrode wires are passed through the skin just above the gluteal region and are marked S and P. One of the sub-investigators (not involved in the follow-up) replaces the S and P marks by 1 and 2 marks in absence of the operating surgeon. Assignment of 1 and 2 is carried out in a predefined randomized fashion (computerized block randomization).

Test phase:

• Electrode labeled 1 is connected to a stimulator and the nerve is stimulated for one week, then the other electrode is stimulated for a week.
• Based on bowel habit diary, Wexner score (Jorge 1993) and subjective experience of the patient, the more successful treatment is chosen. If both electrodes were equally successful, the pudendal nerve electrode will be chosen for permanent stimulation.

Secondary surgery:

• After unblinding, the less effective electrode is removed and the remaining electrode is connected to an implanted stimulator (permanent phase). In case both treatments were unsuccessful, both electrodes are removed.

• Procedure: Sacral nerve modulation
  For one week the sacral nerve is continuously stimulated by an external pulse generator. Strength of stimulation can be adjusted by the patient.
  Other Names:

  • SNM
  • Sacral nerve stimulation
  • SNS
• Procedure: Pudendal nerve stimulation
  For one week the pudendal nerve is continuously stimulated by an external pulse generator. Strength of stimulation can be adjusted by the patient.
  Other Name: PNS

• Experimental: Sacral nerve modulation first
  Sacral nerve modulation is applied before the pudendal nerve stimulation. There is no "wash-out" period (pause) between the two treatments.
  Interventions:

  • Procedure: Sacral nerve modulation
  • Procedure: Pudendal nerve stimulation
• Experimental: Pudendal nerve stimulation first
  Pudendal nerve stimulation is applied before the sacral nerve modulation. There is no "wash-out" period (pause) between the two treatments.
  Interventions:

  • Procedure: Sacral nerve modulation
  • Procedure: Pudendal nerve stimulation

• Spinelli M, Sievert KD. Latest technologic and surgical developments in using InterStim Therapy for sacral neuromodulation: impact on treatment success and safety. Eur Urol. 2008 Dec;54(6):1287-96. Epub 2008 Feb 8. Review.
• Spinelli M, Malaguti S, Giardiello G, Lazzeri M, Tarantola J, Van Den Hombergh U. A new minimally invasive procedure for pudendal nerve stimulation to treat neurogenic bladder: description of the method and preliminary data. Neurourol Urodyn. 2005;24(4):305-9.
• Jorge JM, Wexner SD. Etiology and management of fecal incontinence. Dis Colon Rectum. 1993 Jan;36(1):77-97. Review.
• Rockwood TH, Church JM, Fleshman JW, Kane RL, Mavrantonis C, Thorson AG, Wexner SD, Bliss D, Lowry AC. Fecal Incontinence Quality of Life Scale: quality of life instrument for patients with fecal incontinence. Dis Colon Rectum. 2000 Jan;43(1):9-16; discussion 16-7.
• Dindo D, Demartines N, Clavien PA. Classification of surgical complications: a new proposal with evaluation in a cohort of 6336 patients and results of a survey. Ann Surg. 2004 Aug;240(2):205-13.

Inclusion Criteria:

• fecal incontinence nonresponsive to conservative treatment

Exclusion Criteria:

• sacral or perineal infection
• sphincter defect larger than 60° (sonography)
• pregnancy