Neurostimulation for neurogenic bowel dysfunction.

Background. Loss of normal bowel function caused by nerve injury, neurological disease or congenital defects of the nervous system is termed neurogenic bowel dysfunction (NBD). It usually includes combinations of fecal incontinence, constipation, abdominal pain and bloating. When standard treatment of NBD fails surgical procedures are often needed. Neurostimulation has also been investigated, but no consensus exists about efficacy or clinical use. Methods. A systematic literature search of NBD treated by sacral anterior root stimulation (SARS), sacral nerve stimulation (SNS), peripheral nerve stimulation, magnetic stimulation, and nerve re-routing was made in Pubmed, Embase, Scopus, and the Cochrane Library. Results. SARS improves bowel function in some patients with complete spinal cord injury (SCI). Nerve re-routing is claimed to facilitate defecation through mechanical stimulation of dermatomes in patients with complete or incomplete SCI or myelomeningocele. SNS can reduce NBD in selected patients with a variety of incomplete neurological lesions. Peripheral stimulation using electrical stimulation or magnetic stimulation may represent non-invasive alternatives. Conclusion. Numerous methods of neurostimulation to treat NBD have been investigated in pilot studies or retrospective studies. Therefore, larger controlled trials with well-defined inclusion criteria and endpoints are recommended before widespread clinical use of neurostimulation against NBD.

Turning off sacral nerve stimulation does not affect gastric and small intestinal motility in patients treated for faecal incontinence.

AIM: Sacral nerve stimulation (SNS) reduces symptoms in up to 80% of patients with faecal incontinence (FI). Its effects are not limited to the distal colon and the pelvic floor. Accordingly, spinal or supraspinal neuromodulation have been suggested as part of the mode of action. The effect of SNS on gastric and small-intestinal motility was studied. METHOD: Using the magnet tracking system, MTS-1, a small magnetic pill was tracked twice through the upper gastrointestinal tract of eight patients with FI successfully treated with SNS. Following a randomized double-blind crossover design, the stimulator was either left active or was turned off for 1 week before investigations with MTS-1. RESULTS: The median (range) frequency of gastric con-tractions was 3.05 (2.83-3.40) per min during SNS and 3.04 (2.79?-3.76) per min without (P=NS). The median (range) frequency of contractions in the small intestine during the first 2h after pyloric passage was 10.005 (9.68-10.70) per min during SNS and 10.09 (9.79-10.29) per min without SNS (P=NS). The median (range) velocity of the magnetic pill during the first 2h in the small intestine was 1.6 (1.2-2.8) cm/min during SNS and 1.7 (0.8-3.7) cm/min without SNS (P=NS). Small-intestinal propagation mainly occurred during very fast movements (>15cm/min), accounting for 51% (42-60%) of the distance 3% (2-4%) of the time during SNS and for 53% (18-73%) of the distance 3% (1-8%) of the time without SNS (P=NS). CONCLUSION: Turning off SNS for 1week did not affect gastric or small-intestinal motility patterns.

Acute effect of electrical stimulation of the dorsal genital nerve on rectal capacity in patients with spinal cord injury.

BACKGROUND: Constipation and fecal incontinence are considerable problems for most individuals with spinal cord injury (SCI). Neurogenic bowel symptoms are caused by several factors including abnormal rectal wall properties. Stimulation of the dorsal genital nerve (DGN) can inhibit bladder contractions and because of common innervation inhibitory effects are anticipated in the rectum too. Therefore, DNG could have a future role in the treatment of neurogenic fecal incontinence. AIM: To study the effect of acute DGN stimulation on the rectal cross sectional area (CSA) in SCI patients. METHODS: Seven patients with complete supraconal SCI (median age 50 years) were included. Stimulation was applied via plaster-electrodes using an amplitude of twice the genito-anal reflex threshold (pulse width: 200 µs; pulse rate: 20 Hz). A pressure controlled phasic (10, 20 and 30 cmH(2)O) rectal distension protocol was repeated four times with subjects randomized to stimulation during 1st and 3rd distension series or 2nd and 4th distension series. The rectal CSA and pressure were measured using impedance planimetry and manometry. RESULTS: All patients completed the investigation. Median stimulation amplitude was 51 mA (range 30-64). CSA was smaller during stimulation and differences reached statistical significance at distension pressures of 20 cmH(2)O (average decrease 9%; P = 0.02) and 30 cmH(2)O (average decrease 4%; P = 0.03) above resting rectal pressure. Accordingly, rectal pressure-CSA relation was significantly reduced during stimulation at 20 (P=0.03) and 30 cmH(2)O distension (P=0.02). CONCLUSION: DGN Stimulation in patients with supraconal SCI results in an acute decrease of rectal CSA and the rectal pressure-CSA relation.

Gastric and small intestinal dysfunction in spinal cord injury patients.

BACKGROUND: Many patients with spinal cord injury (SCI) suffer from constipation, abdominal pain, nausea, or bloating, and colonic transit times are prolonged in most. Gastric and small intestinal dysfunction could contribute to symptoms but remain to be described in detail. Also, it is obscure whether the level of SCI affects gastric and small intestinal function. AIM: To study orocecal transit time and gastric emptying (GE) in patients with SCI. METHODS: Nineteen patients with SCI (7 ♀, median age 54 years) and 15 healthy volunteers (9 ♀, median age 32 years) were included. All were referred because of neurogenic bowel problems. Eleven patients had low SCI (located at conus medullaris or cauda equina) affecting only the parasympathetic nerves to the left colon and eight had high SCI (above Th6) affecting parasympathetic and sympathetic innervation. Subjects ingested a small magnetic pill that subsequently was tracked by the Motility Tracking System - MTS-1 (Motilis, Lausanne, Switzerland). RESULTS: Orocecal transit time was longer than normal both in individuals with high lesions (P < 0.01) and in individuals with low lesions (P < 0.01). Individuals with high lesions had slower GE than those with conal/cauda equina lesions (P < 0.05). Basic contractile frequencies of the stomach and small intestine were unaffected by SCI. CONCLUSION: Surprisingly, upper gastrointestinal transit is prolonged in subjects with SCI suffering from bowel problems, not only in subjects with cervical or high thoracic lesions but also in subjects with conal/cauda equina lesions. We speculate that this is secondary to colonic dysfunction and constipation.

Electrical stimulation of the dorsal clitoral nerve reduces incontinence episodes in idiopathic faecal incontinent patients: a pilot study.

AIM: Faecal incontinence (FI) has a significant impact on quality of life. This study investigates whether stimulation of the dorsal genital nerve (DGN) improves FI symptoms. METHOD: Ten female patients suffering from idiopathic FI (median age 60 years) were included in the study. Stimulation was applied twice daily for 3 weeks at the maximal tolerable stimulation amplitude (pulse width, 200 µs; pulse rate, 20 Hz). Patients kept a 3-week bowel diary prior to stimulation, during stimulation and after the final stimulation. FI severity scores, FI Severity Visual-Analogue Score (VAS), FI Quality of Life Score (FIQL), sphincter function and rectal volume tolerance were assessed at baseline, immediately after stimulation and 3 weeks after stimulation. RESULTS: Nine patients completed the study. The Wexner score (P=0.027) and the St Mark's score (P=0.035) improved after stimulation in seven and six of the patients and improvement was maintained 3 weeks after stimulation (P=0.048 and P=0.049, respectively). The number of incontinent episodes was reduced in seven out of nine patients (P=0.025). Improvement was maintained for 3 weeks after stimulation (P=0.017). Subjective assessments of FI severity using the VAS score and the FIQl score did not improve during stimulation. Sphincter function and rectal volume tolerability were unaffected. CONCLUSION: DGN stimulation reduced the number of FI episodes in most patients suffering from idiopathic FI. Sphincter function and rectal volume tolerability were not affected. DGN stimulation may represent a new treatment for idiopathic FI.

Faecal incontinence in patients with systemic sclerosis: is an impaired internal anal sphincter the only cause?

OBJECTIVES: Faecal incontinence affects 40% of patients with systemic sclerosis (SSc). Several factors, including impaired anal sphincter function, reduced rectoanal sensation, abnormal rectoanal wall properties, and fast gastrointestinal transit, can cause faecal incontinence. Internal anal sphincter function is reduced in some patients with SSc, but other factors causing faecal incontinence remain to be studied in detail. Our aim was to compare tests of colorectal and anal physiology in patients with SSc suffering from faecal incontinence to those of SSc patients without faecal incontinence and healthy controls. METHODS: Twenty SSc patients [18 women, mean age 58 (range 38-79) years] with bowel dysfunction were examined using rectoanal physiology tests, impedance planimetry, radiographic assessment of gastrointestinal transit time, and the Wexner incontinence score questionnaire. The results from SSc patients with faecal incontinence (n = 8) were compared to those from patients without faecal incontinence (n = 12) and healthy subjects [rectoanal physiology tests: 24 women, mean age 72 (range 65-83) years; impedance planimetry: 20 women, mean age 51 (range 40-80) years]. RESULTS: Anal resting pressure, which reflects internal anal sphincter function, was significantly reduced in SSc patients with faecal incontinence but not in those without. There were no significant differences in external anal sphincter function, rectoanal sensibility, rectal wall properties, or gastrointestinal transit time. CONCLUSION: The main cause of faecal incontinence in SSc is poor function of the internal anal sphincter smooth muscle.

The acute effect of dorsal genital nerve stimulation on rectal wall properties in patients with idiopathic faecal incontinence.

AIM: Faecal continence depends on several factors, including rectal wall properties. Stimulation of the dorsal genital nerve (DGN) can suppress bladder contraction and similar effects are anticipated for the rectum. In this study, the acute effect of DGN stimulation on the rectal cross-sectional area is investigated. METHOD: Ten female patients (median age 60 years) with idiopathic faecal incontinence were included in the study. Stimulation was applied via plaster electrodes with the maximum tolerable amplitude (pulse width was 200 µs at a pulse rate of 20 Hz). Three series of pressure-controlled phasic (10, 20 and 30 cm H(2) O) and stepwise (5-30 cm H(2) O in steps of 5 cm H(2) O) rectal distensions were conducted (unstimulated, stimulated, unstimulated), and the rectal cross-sectional area (CSA) was measured with impedance planimetry. RESULTS: All patients completed the investigation. The median stimulation amplitude was 21 (8.5-27) mA. Comparing stimulated with unstimulated phasic distension, there was no significant difference in the median rectal CSA. Comparing stimulated with unstimulated stepwise distension, there was no significant difference in the median rectal CSA. Neither the rectal pressure-CSA relationship (CSA/P(R) ) nor the rectal wall tension changed during stimulation. CONCLUSION: No acute effect on rectal CSA during pressure-controlled distension was demonstrated during DGN stimulation.

Rectal motility in patients with idiopathic fecal incontinence: a study with impedance planimetry.

INTRODUCTION: Most patients with fecal incontinence have poor anal sphincter function. In patients with idiopathic fecal incontinence no structural abnormality can be identified. The aim of the present study was to compare rectal motility patterns in patients with idiopathic fecal incontinence and in healthy controls. METHODS: Rectal impedance planimetry provides simultaneous measurement of rectal pressure, anal pressure, and rectal cross-sectional area at 5 levels. This allows highly detailed description of rectoanal motility. In 12 female patients with idiopathic fecal incontinence (mean age, 64.5) and 12 healthy controls (mean age, 47; 12 females) rectal phasic activity and tone were studied at a distension pressure 10 cm H2O above basic rectal pressure for one hour during fast and one hour after the meal. RESULTS: The median rectal cross-sectional area during fast was 3178 mm2 (range, 1905-4095) in patients with fecal incontinence and 2907 mm2 (range, 1832-4195) in the control group (P = .42). The postprandial decrease in rectal cross-sectional area was significantly more pronounced in patients (median postprandial reduction 462 mm2 (range, 3124 reduction to 7 increase)) than in the control group (median postprandial change 33 mm2 (range, 844 reduction to 974 increase)) (P = .007). The number of anal sampling reflexes during fast was reduced in patients (P = .03) and rectal wall tension during anal sampling reflexes also tended to be lower (P = .07). No differences in other phasic rectal motility patterns were found. CONCLUSION: Idiopathic fecal incontinence is associated with enhanced postprandial increase in rectal tone and a reduced frequency of anal sampling reflexes.

Rectal motility after sacral nerve stimulation for faecal incontinence.

Sacral nerve stimulation (SNS) is effective against faecal incontinence, but the mode of action is obscure. The aim of this study was to describe the effects of SNS on fasting and postprandial rectal motility. Sixteen patients, 14 women age 33-73 (mean 58), with faecal incontinence of various aetiologies were examined. Before and during SNS, rectal cross-sectional area (CSA) and ano-rectal pressures were determined with impedance planimetry and manometry for 1 h during fast and 1 h postprandially. Neither in the fasting state nor postprandially did SNS affect the number of single rectal contractions, total time with cyclic rectal contractions, the number of aborally and orally propagating contractions, the number of anal sampling reflexes or rectal wall tension during contractions. Postprandial changes in rectal tone were significantly reduced during SNS (P < 0.02). Before SNS, median rectal CSA was 2999 mm(2) (range: 1481-3822) during fast and 2697 mm(2) (range: 1227-3310) postprandially (P < 0.01). During SNS, median rectal CSA was 2990 mm(2) (1823-3678) during fast and 2547 mm(2) (1831-3468) postprandially (P = 0.22). SNS for faecal incontinence does not affect phasic rectal motility but it impairs postprandial changes in rectal tone.

Long-term results of antegrade colonic enema in adult patients: assessment of functional results.

PURPOSE: This retrospective study reviewed long-term results in a large group of adult patients treated with antegrade colonic enema and antegrade colonic enema combined with a colostomy. METHODS: Retrospective chart review identified 80 patients (64 females, mean age 51) surgically treated between 1993 and 2007 for fecal incontinence or constipation. Surgical treatments included 69 appendicostomies, 13 tapered ileum, 3 cecal tube, and 25 appendicostomy/neoappendicostomy combined with a colostomy. A 44-item questionnaire was mailed considering bowel regimen, complications, bowel function, social function, and quality of life. RESULTS: Sixty-nine patients were available for follow-up (mean follow-up, 75 months). Thirty patients (38 percent) had surgical complications. Forty-three patients (62 percent) were still performing antegrade continence enema and 8 patients (12 percent) no longer needed it. Accordingly, treatment was successful in 51 patients (74 percent). Twenty-seven patients (63 percent) had side effects. Evaluation of bowel function, social function, and quality of life all showed significant improvement. Antegrade continence enema was successful in patients with neurologic disabilities (67 percent), anorectal injury (53 percent), idiopathic fecal incontinence (50 percent), and idiopathic fecal constipation (42 percent). Antegrade continence enema was successful in patients with constipation, incontinence, and mixed symptoms. Results did not differ between appendicostomy, neoappendicostomy, and the combined appendicostomy/neoappendicostomy and colostomy. CONCLUSION: Long-term results were favorable in most patients treated with antegrade continence enema for fecal incontinence or constipation.