DDW: Sacral Nerve Stimulation Relieves Refractory Constipation

WASHINGTON, May 20 -- Sacral nerve stimulation may be an effective alternative to surgery for patients whose idiopathic constipation doesn't respond to laxatives or biofeedback, researchers reported here.

In patients with refractory constipation who tried sacral nerve stimulation, the frequency of bowel movements nearly doubled while abdominal pain was halved and episodes of straining were reduced, reported Thomas C. Dudding, M.D., of St. Mark's Hospital in London, at Digestive Disease Week here.

Surgical procedures such as colectomy have high failure rates and can cause substantial morbidity, including persistent abdominal pain in about two-thirds of cases, according to several recent studies, Dr. Dudding said.

Sacral nerve stimulation, which is approved by the FDA for urinary incontinence, involves surgically placing a lead wire with a small electrode tip near the sacral nerve in the lower spine. This nerve controls voiding function. A nerve-stimulator device, similar to a pacemaker, sends small, continuous electrical impulses to the sacral nerve, Dr. Dudding said.

A prospective, multicenter study he reported included 65 patients (58 female) who had failed treatment with laxatives and biofeedback. Patient served as their own controls. They ranged in age from 17 to 79 (median age, 40).

After 21 days of sacral nerve stimulation treatment with a temporary device worn on the belt, 43 of the patients (66%) had a 50% or greater improvement in symptoms, the study found.

These patients were given long-term sacral nerve stimulation therapy with a permanent device implanted under the skin. After a median follow-up of 12 months, key results from this patient group included the following:

• Frequency of bowel movements increased from an average of 3.4 to 6.1 times per week (P<0.001).
• Days on which a bowel movement occurred increased from an average of 2.4 to 4.4 per week (P<0.001).
• The average time spent on the toilet decreased from 17.6 to 9.3 minutes per episode (P<0.001).
• Episodes of straining decreased from 4.4 to 2.9 per week (P=0.114)
• Abdominal pain decreased from 4.4 to 2.0 days per week (P<.001).

Patients also improved as measured by the Cleveland Clinic constipation score (CCCS), which ranges from 0 (no constipation) to 30 (severe constipation). The mean CCCS score fell from 18 at baseline to 10.2 at follow-up (P<0.001).

In addition, symptoms improved as measured by a visual analog score (VAS), which ranged from 0 (severe symptoms) to 100 (no symptoms). The mean VAS score improved from 18 at baseline to 66 at follow-up (P<0.001).

And according to the short form-36 quality-of-life questionnaire, patients significantly improved in the areas of physical functioning, general health, vitality, social functioning, and mental health (data and P values not given).

One limitation of the study is that the short-form 36 is not a disease-specific quality of life assessment, Dr. Dudding noted.

Finally, in the 30 patients found to have slow colonic transit times at baseline, colonic transit times normalized for about half, the study found.

"Sacral nerve stimulation is effective in the treatment of idiopathic constipation resistant to conservative treatment," the authors concluded. "Improvement occurs in bowel frequency, associated symptoms, quality of life, and objectively measured colonic transit."