Electrophysiologic assessments in pudendal and sacral motor nerves after ileal J-pouch-anal anastomosis for patients with ulcerative colitis and adenomatosis coli

A systematic review of sacral nerve stimulation for faecal incontinence following ileal pouch anal anastomosis

Faecal incontinence is a common complication of ileal pouch anal anastomosis (IPAA) and seems to worsen with time. The aim of this paper is to review the evidence of the use of sacral nerve stimulation (SNS) for patients with faecal incontinence after IPAA. A literature search was performed on PubMed and Cochrane databases for all relevant articles. All studies, which reported the outcome of SNS in patients with faecal incontinence after IPAA, were reviewed. Three papers were identified, including a case report, cohort study and retrospective study. The total number of patients was 12. The follow-up duration included 3 months, 6 months and 24 months. After peripheral nerve evaluation, definitive implantation was performed in 10 (83.3%) patients. All three studies reported positive outcomes, with CCF scores and incontinence episodes improving significantly. Preliminary results suggest good outcome after permanent SNS implant. Studies with larger sample sizes, well-defined patient characteristics and standardized outcome measures are required to fully investigate the effect of SNS in IPAA patients.

Evaluation of vector manometry for characterization of functional outcome after restorative proctocolectomy

AIM

The impact of 3-dimensional vector manometry (VM) for characterization of the functional outcome of restorative proctocolectomy (RP) was studied in 61 patients at a median of 86 months after RP for ulcerative colitis.

METHODS

A 14-day continence diary was utilized to quantify continence, urgency, and the frequency of defecation. The clinical outcome data were correlated to the physiology parameters of VM and volumetry.

RESULTS

VM parameters at rest correlated with postoperative continence but not substantially with stool frequency and urgency. High radial asymmetry was significantly correlated with the degree of incontinence (r=0.333, p=0.013). Resting pressures demonstrated a better correlation with the degree of incontinence when documented for the high-pressure zone (HPZ; portion of the sphincter with at least 50% of the maximum pressure; r=0.301, p=0.025) and when performed in the continuous pull-through technique. Stool frequency and urgency were better characterized by volumetry parameters like threshold volumes and pouch compliance. The specificity and sensitivity of the vector volume at rest of the HPZ for the prediction of incontinence was 63.6% and 59.1%, respectively. The corresponding values were 67% and 68%, respectively, for radial asymmetry at rest. Stool frequency and urgency were better characterized by volumetry parameters like threshold volumes and pouch compliance.

CONCLUSION

A strong anal sphincter at rest and a consistent radial distribution of the sphincter pressure are the most reliable indicators of continence after RP obtained by VM, but their clinical usefulness is limited.

Assessments of anal canal sensitivity in patients with soiling 5 years or more after colectomy, mucosal proctectomy, and ileal J pouch-anal anastomosis for ulcerative colitis

INTRODUCTION

To clarify the significance of anal canal sensitivity contribution to soiling in patients after ileal J pouch-anal anastomosis (IPAA) for ulcerative colitis (UC), we studied the sensory function of the anal canal.

METHODS

Forty patients with UC who had undergone IPAA with ileostomy closure at least 60 to 132 months (mean 103.6 months) previously, and who had no preoperative or postoperative complications were recruited. They were divided into two groups: group A [n = 26; patients without soiling (16 males, 10 females; ages 15-49 years, mean 36.6 years)] and group B [n = 14; patients with soiling (10 men, 4 women; ages 24-56 years, mean 40.9 years)] compared with group C [n = 28; control subjects (18 men, 10 women; aged 19-49 years, mean 38.5 years)]. Patients with soiling were also divided into three groups (B1, rare soiling; B2, occasional soiling; B3, frequent soiling). The anal canal sensitivity threshold was measured using an anal canal electrosensitivity test (ACEST). The measurement point of anal canal was divided into three parts: lower part [1 cm below the dentate line (DL), middle part (just on the DL), and upper part (1 cm above the DL]. A small electric current from a constant-current generator was passed between the electrodes until the patient felt a sensation often described as tingling or pulsing. The threshold of sensitivity was assessed in the upper, middle, and lower parts of the anal canal.

RESULTS

In patients of group C, recording at the middle part of the anal canal showed the best results. The anal canal sensitivity threshold of group B was significantly higher than those of groups A and C at the upper and middle parts (P < 0.0001, respectively). There were no significant differences at the lower part among groups. The anal canal sensitivity threshold of subgroup B3 was significantly higher than those of groups B1 or B2 at both the upper part (P = 0.0002, P = 0.0038, respectively) and middle part (P = 0.0001, P = 0.0480, respectively). There were no significant differences at the lower part among groups.

CONCLUSIONS

The ACEST shows significantly lower sensitivity in the proximal and middle anal canal in IPAA patients with soiling.

Pudendal Nerve Terminal Motor Latency in Patients With or Without Soiling 5 Years or more after Low Anterior Resection for Lower Rectal Cancer

BACKGROUND

To clarify the neurological function with respect to external anal sphincter (EAS) muscles in patients with or without soiling after low anterior resection (LAR) for lower rectal cancer, we examined the terminal motor latency in the pudendal motor nerves (PNTML).

MATERIALS AND METHODS

Thirty-eight patients after LAR for lower rectal cancer were studied electrophysiologically and compared with 30 healthy volunteers as controls (19 men and 11 women, aged 44 to 76 years of age, with a mean age of 65.5 years). Patients after LAR were divided into two groups [18 patients with soiling (12 men and 6 women, aged 51 to 77 years with a mean age of 64.8 years), 20 patients without soiling (13 men and 7 women, aged 47 to 75 years with a mean age of 62.1 years)]. The mean follow-up time from LAR was 67.2 months (range 60-84 months). Bilateral (left-sided and right-sided) PNTML tests were performed on all patients in order to measure the latency of the response in the bilateral EAS muscle following digitally directed transrectal pudendal nerve stimulation.

RESULTS

The distance from the anal verge to the level of anastomosis in patients with soiling (mean, 2.2 cm) was significantly shorter than that in patients without soiling (mean, 4.1 cm) (P < 0.05). Conduction delay of the bilateral PNTML in patients with soiling was longer than that in patients without soiling and normal subjects, significantly (P < 0.01, respectively). There was no significant difference between the right-sided and left-sided PNTML.

CONCLUSIONS

These findings support the hypothesis that soiling after LAR may be partially caused by damage to the bilateral pudendal motor nerves.

Neurophysiological testing in anorectal disorders

The neurophysiological techniques currently available to evaluate anorectal disorders include concentric needle electromyography (EMG) of the external anal sphincter, anal nerve terminal motor latency (TML) measurement in response to transrectal electrical stimulation or sacral magnetic stimulation, motor evoked potentials (MEPs) of the anal sphincter to transcranial magnetic cortical stimulation, cortical recording of somatosensory evoked potentials (SEPs) to anal nerve stimulation, quantification of electrical or thermal sensory thresholds (QSTs) within the anal canal, sacral anal reflex (SAR) latency measurement in response to pudendal nerve or perianal stimulation, and perianal recording of sympathetic skin responses (SSRs). In most cases, a comprehensive approach using several tests is helpful for diagnosis: needle EMG signs of sphincter denervation or prolonged TML give evidence for anal motor nerve lesion; SEP/QST or SSR abnormalities can suggest sensory or autonomic neuropathy; and in the absence of peripheral nerve disorder, MEPs, SEPs, SSRs, and SARs can assist in demonstrating and localizing spinal or supraspinal disease. Such techniques are complementary to other methods of investigation, such as pelvic floor imaging and anorectal manometry, to establish the diagnosis and guide therapeutic management of neurogenic anorectal disorders.

Intrarectal ground electrode improves the reliability of motor evoked potentials recorded in the anal sphincter

Motor evoked potentials (MEPs) can be recorded in the external anal sphincter in response to magnetic stimulation of the cerebral cortex or sacral roots. However, the magnitude of the stimulus artifact may alter the reliability of anal MEP recording. An intrarectal ground electrode substantially reduces stimulus artifact and technical failure, improving MEP latency determination to sacral root stimulation in particular.

Gastric emptying function after ileal J pouch-anal anastomosis for ulcerative colitis

BACKGROUND

Little is known of the effects on gastric function after ileal J pouch-anal anastomosis (IPAA) for ulcerative colitis. This study aimed to determine whether patients with postoperative high stool frequency after IPAA exhibit impaired gastric function.

METHODS

Gastric emptying time (GET) for a solid diet (rice gruel) with the use of a radioisotope method and for a liquid diet (orange juice) with the use of an acetaminophen method were assessed in 36 patients with ulcerative colitis more than 30 months after closure of protective ileostomy. Patients were divided into 2 groups: 18 patients with stool frequency less than 6 per day (group A) and 18 patients with stool frequency more than 7 per day (group B). GET for solid and liquid diets in groups A and B were compared with those in 18 healthy volunteers (group C). We correlated the time of peak blood concentration of acetaminophen (TPBCA) and both individual stool frequency per day and the length of distal ileum removed.

RESULTS

GET for the solid diet in groups A and B was not altered by IPAA compared with group C. GET for the liquid diet in groups A and B was slower than in group C (P<.0001). GETs for the liquid diet at 60 minutes or more in group A were slower than in group B (P<.0001); TPBCA was longer in group A than in groups B or C (P<.01). There were inverse correlations between TPBCA and individual stool frequency per day and between TPBCA and length of distal ileum removed (P<.001).

CONCLUSIONS

Rapid transit from the stomach of the liquid diet in group B compared with group A may influence high stool frequency after IPAA. Our results suggested that, to obtain an adequate stool frequency after IPAA, the length of distal ileum removal should be less than 15 cm.

Relationship between gastrointestinal transit time and daily stool frequency in patients after Ileal J pouch-anal anastomosis for ulcerative colitis

BACKGROUND

To investigate how the gastrointestinal transit function changes after ileal J pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) and to study whether gastrointestinal transit time (GTT) has an influence on daily stool frequency, we investigated the relationship between GTT and stool frequency per day.

METHODS

Forty patients with UC who had undergone restorative proctocolectomy, with ileostomy closure at least 48 to 120 months (mean 96.3) previously, and who had no preoperative and postoperative complications were recruited. They were divided into two groups on the basis of their stool frequency: 26 patients had a stool frequency of less than 6 times per day (group A: 16 men, 10 women; aged 15 to 59 years old, average 36.6) and 14 patients had a stool frequency of 7 or more times per day (group B: 10 men, 4 women; 24 to 56 years old, average 40.9). The GTTs using a radiopaque marker were studied. Interviews concerning the defecation states were performed at the examination.

RESULTS

High nocturnal stool frequency was significantly noted more in group B than in group A (P <0.001). All cases in group A and 12 cases in group B could discriminate flatus from feces, and there were significant differences between groups A and B (P <0.05). Feeling of stool remaining was significantly noted more in group B than in group A (P <0.01). Stool consistency in group A was harder than that in group B (P <0.001). Patients with soiling were significantly noted more in group B compared with those in group A (P <0.001). Incontinence was detected in only 2 cases in group B. Group A showed a better defecation state than group B. In the GTT study, the GTT was almost the same in groups A and B. The small bowel transit, pouch transit, and whole gut transit times in group B were faster than those of group A (P <0.001). Removal length of the terminal ileum in patients after IPAA: patients in group B (13.8 +/- 3.9 cm) had significantly more ileum removed compared with patients in group A (6.3 +/- 2.4 cm; P <0.001). Regression lines in the relationship between removal length of the terminal ileum and individual stool frequency showed there was a correlation between removal length of the terminal ileum and individual stool frequency per day in direct proportion (r = 0.79, P <0.001). A resection of more ileum, up to 15 cm, plays a role in increased stool frequency.

CONCLUSIONS

The present results suggested that rapid transit of both the small bowel and pouch may lead to a high stool frequency of 7 or more times per day with a poor defecation state after IPAA. It was also pointed out in this study that an important point is a resection of more ileum, up to 15 cm, plays a role in increased stool frequency.

Latency of compound muscle action potentials of the anal sphincter after magnetic sacral stimulation

The aim of this study was to present the failure rate and normal values for motor latency of the anal sphincter after magnetic sacral stimulation (LMSS) using a modified recording technique. A bipolar sponge electrode was placed in the anal canal for recording. A ground electrode was placed in the rectum to reduce stimulus artifact. Magnetic stimulation was induced through a twin coil energized by a Maglite-r25 generator. Two groups were examined: 14 healthy volunteers and 14 patients with a spinal cord injury (SCI) above the conus. Nine of 56 studies (16%) failed. There were no significant differences in latency between right- and left-sided stimulation or between the healthy group and the SCI patients. As described, LMSS measurements are minimally invasive and have a low failure rate. They may be used to test the integrity of the distal motor pathway in patients with bladder or bowel dysfunction who may benefit from continuous electrical sacral root stimulation.

Evaluation of the sacroanal motor pathway by magnetic and electric stimulation in patients with fecal incontinence

PURPOSE

The aim of this controlled study was to examine whether it was feasible to use magnetic stimulation as a new diagnostic tool to evaluate the motor function of the sacral roots and the pudendal nerves in patients with fecal incontinence.

PATIENTS AND METHODS

Nineteen consecutive patients (17 females) with a median age of 67 (range, 36-78) years referred for fecal incontinence and 14 healthy volunteers (six females) with a median age of 42 (range, 23-69) years were examined. Latency times of the motor response of the external anal sphincter were measured after electric transrectal stimulation of the pudendal nerve and magnetic stimulation of the sacral roots.

RESULTS

The success rates of pudendal nerve terminal motor latency and sacral root terminal motor latency measurements were 100 and 85 percent, respectively, in the control group and 94 and 81 percent, respectively, in the fecal incontinence group. Median left pudendal nerve terminal motor latency was 1.88 (range, 1.4-2.9) milliseconds in the control group and 2.3 (range, 1.8-4) milliseconds in the fecal incontinence group (P < 0.006). Median right pudendal nerve terminal motor latency was 1.7 (range, 1.3-3.4) milliseconds in the control group and 2.5 (range, 1.7-6) milliseconds in the fecal incontinence group (P < 0.003). Median left sacral root terminal motor latency was 3.3 (range, 2.1-6) milliseconds in the control group and 3.7 (range, 2.8-4.8) milliseconds in the fecal incontinence group (P < 0.03). Median right sacral root terminal motor latency was 3 (range, 2.6-5.8) milliseconds in the control group and 3.9 (range, 2.5-7.2) milliseconds in the fecal incontinence group (P = 0.15).

CONCLUSIONS

Combined pudendal nerve terminal motor latency and sacral root terminal motor latency measurements may allow us to study both proximal and distal pudendal nerve motor function in patients with fecal incontinence. Values of sacral root terminal motor latency have to be interpreted cautiously because of the uncertainty about the exact site of magnetic stimulation and the limited magnetic field strength.