Percutaneous Tibial Nerve Stimulation - an Alternative Treatment Option for Chronic Therapy Resistant Anal Fissure
Condition: Chronic Anal Fissure
MeSH terms: Fissure in Ano
Study type: Interventional

Summary: 
      At a tertiary referral centre, 10 patients (4 male and 6 female; mean age 49.8 years) were
      given neuromodulation via the posterior tibial nerve to the sacral nerve for 30 min on 10
      consecutive days. All patients had failed conventional medical treatment. The visual analogue
      scale (VAS), St. Marks score, Wexner's constipation score, Brief Pain Inventory (BPI - SF),
      bleeding and mucosal healing were evaluated before treatment, at termination, after 3 months
      and then yearly during three years.
    

Detailed description: 
      Between October 2013 and January 2014, 10 patients diagnosed with chronic anal fissure at the
      Pelvic Floor Centre - University Hospital of Malmo, Sweden were treated with percutaneous
      tibial nerve stimulation. Ethical clearance to use the results in a scientific setting was
      obtained from the ethics committee of the University of Lund, Sweden (Dnr 2016/998).
      Pre-treatment evaluation included detailed medical history and anorectal examination. All
      patients presented with pain and/or bleeding and the presence of a chronic anal fissure was
      confirmed by clinical examination.

      Patients were included in the study if they were older than 18 years and had symptoms of
      chronic anal fissure for at least 6 months. All patients must have been on high fiber diet
      and stool softeners and in addition failed all conservative pharmacological treatment with
      topical application of anaesthetic creams, muscle relaxants (nitroglycerin or diltiazem)
      and/or botulinum toxin injection. We excluded patients with pregnancy, pacemaker device, low
      molecular heparin or warfarin treatment, neurological disease, inflammatory bowel disease and
      radiation proctitis. The Visual Analog Scale (VAS), St. Marks Incontinence Score, Wexner´s
      Constipation Score, Brief Pain Inventory - Short form (BPI-SF), symptom relief, bleeding and
      mucosal fissure healing were evaluated before and after treatment. VAS and BPI-SF were used
      to measure subjective pain characteristics and symptoms of patients at baseline, after two
      weeks (end of treatment), three months and then after one, two and three years. St. Marks
      Score and Wexner´s Constipation Score were evaluated in the same way though only up to one
      year after completion of treatment. The patients were given percutaneous tibial nerve
      stimulation after obtaining informed consent. The procedure was performed by two experienced
      pelvic floor therapists. Patients retained their high fiber diet and stool softeners during
      the procedure. Percutaneous tibial nerve stimulation was performed by using the Urgent PC
      Neuromodulation System ® (Uroplasty, Holland) on an outpatient basis. A stimulator provides
      electrical current with a fixed pulse frequency of 20Hz, pulse width 200 µ seconds and
      current setting between 0.5 and 9 mA (amplitude). A surface electrode was placed at the
      medial arch of the midfoot and a needle electrode was inserted through the skin posterior to
      the medial malleolus and advanced towards the posterior tibial nerve. Stimulation was
      gradually increased until a tingling sensation was perceived in the foot, or a motor flexor
      response was observed at the big toe. All patients received the treatment for 30 minutes 5
      days a week, during 2 consecutive weeks. The clinical state of the fissure was evaluated
      before and after the last treatment session as well at three months and one year (though at
      the 3 month follow up one patient declined clinical examination since he felt completely
      symptom free). The fissure wound was characterized as not healed, partially healed when the
      healing process was visible but not totally complete and healed when no sign of the fissure
      was visible. At two and three years all patients were contacted by phone, and those who had
      symptoms where chronic anal fissure could not be ruled out underwent a clinical examination.

      Statistical analyses:

      The clinical outcome i.e. none healed, partially or totally healed fissure was analysed in
      relation to VAS, mean of St. Marks Incontinence Score and sum of Wexners's Constipation
      Score. These questions were chosen due to their clinical importance and high response rate.
      All analyses were calculated with descriptive statistics due to the few amount of patients.
      All analyses were performed with SPSS 22.
    

Intervention name(s): Percutaneous tibial nerve stimulation
Intervention type(s): Procedure
Intervention description(s): A 20Hz electrical current is given via an electrode inserted through the skin over the posterior tibial nerve above the medial malleolus of the foot and the nerve is stimulated until a motor reflex of the big toe is acheived. Treatment is then continued for 30 minutes at this level. The treatment is then repeated for a total of 10 sessions within a 2 week period.
Intervention model: Single Group Assignment
Intervention model description: Only patients with chronic anal fissures treated
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Key Words: Anal Fissure, tibial nerve stimulation