Rectal Volume Tolerability and Anal Pressures in Patients With Fecal Incontinence Treated With Sacral Nerve Stimulation

Purpose Sacral nerve stimulation has proven to be a promising treatment for fecal incontinence when conventional treatment modalities have failed. There have been several hypotheses concerning the mode of action of sacral nerve stimulation, but the mechanism is still unclear. This study was designed to evaluate the results of rectal volume tolerability, rectal pressure-volume curves, and anal pressures before and six months after permanent sacral nerve stimulation and to investigate the mode of action of sacral nerve stimulation. Methods Twenty-nine patients with incontinence (male/female ratio = 6/23; median age, 58 (range, 29–79) years) underwent implantation of a permanent sacral electrode and neurostimulator after a positive percutaneous nerve evaluation test. Wexner incontinence score, rectal distention with thresholds for “first sensation,” “desire to defecate,” and “maximal tolerable volume,” rectal pressure-volume curves, anal resting pressure, and maximum squeeze pressure were evaluated at baseline and at six months follow-up. Results Median Wexner incontinence score decreased from 16 (range, 6–20) to 4 (range, 0–12; P < 0. 0001). Median “first sensation” increased from 43 (range, 16–230) ml to 62 (range, 4–186) ml (P = 0.1), median “desire to defecate” from 70 (range, 30–443) ml to 98 (range, 30–327) ml (P = 0.011), and median “maximal tolerable volume” from 130 (range, 68–667) ml to 166 (range, 74–578) ml (P = 0.031). Rectal pressure-volume curves showed a significant increase in rectal capacity (P < 0.0001). The anal resting pressure increased significantly from 31 (range, 0–109) cm H₂O to 38 (range, 0–111) cm H₂O (P = 0.045). No significant increase in maximum squeeze pressure was observed. Conclusions For patients with fecal incontinence successfully treated with sacral nerve stimulation, there was a significant increase in rectal volume tolerability and rectal capacity. A significant increase in anal resting pressure, but not in maximum squeeze pressure, was found. We suggest that sacral nerve stimulation causes neuromodulation at spinal level. Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, Philadelphia, Pennsylvania, April 30 to May 5, 2005.     

Anorectal pressure gradient and rectal compliance in fecal incontinence

To study whether anorectal pressure gradients discriminated better than standard anal manometry between patients with fecal incontinence and subjects with normal anal function, anorectal pressure gradients were measured during rectal compliance measurements in 36 patients with fecal incontinence and in 22 control subjects. Anal and rectal pressures were measured simultaneously during the rectal compliance measurements. With standard anal manometry, 75% of patients with fecal incontinence had maximal resting pressure within the normal range, and 39% had maximum squeeze pressure within the normal range. Anorectal pressure gradients did not discriminate better between fecal incontinence and normal anal function, since, depending on the parameters used, 61%–100% of the incontinent patients had anorectal pressure gradients within the normal range. Patients with fecal incontinence had lower rectal volumes than controls at constant defecation urge (median 138 ml and 181 ml, P<0.05) and at maximal tolerable volume (median 185 ml and 217 ml, P<0.05). We conclude that measurements of anorectal pressure gradients offer no advantage over standard anal manometry when comparing patients with fecal incontinence to controls. Patients with fecal incontinence have a lower rectal volume tolerability than control subjects with normal anal function. Accepted: 5 June 1998     

Sacral nerve stimulation for treatment of fecal incontinence

PURPOSE: Many patients with fecal incontinence demonstrate a functional deficit of the internal anal sphincter or the external sphincter muscles without any apparent structural defects. Few patients are amenable to repair or substitution of the sphincter. However, sacral nerve stimulation appears to offer a valid treatment option for fecal incontinence. The objectives of this study were: to evaluate the efficacy of temporary stimulation of the sacral nerve roots (percutaneous nerve evaluation) in patients with functional fecal incontinence; to determine the mechanisms of possible improvement; and to evaluate if temporary stimulation could be reproduced and maintained by implanting a permanent neurostimulation system. METHODS: Twenty-three patients with fecal incontinence, 18 females and 5 males, median age of 54.9 years (range 28–71), underwent a percutaneous nerve evaluation test. Eleven patients (47.8 percent) also had urinary disorders: urge incontinence (4), stress incontinence (3), and retention (4). Associated disorders included perineal and rectal pain (1), spastic paraparesis (1), and syringomyelia (1). All patients underwent a preliminary evaluation using stationary anal manovolumetry, pudendal nerve terminal motor latency measurements, and anal ultrasound. A percutaneous electrode for the stimulation of the sacral nerve roots was positioned at the level of the third sacral foramen (S3) in 20 patients and S2 in 2 patients (1 patient missing). Stimulation parameters used were: pulse width 210µsec, frequency 25 Hz, and average amplitude of 2.8 V (range 1–6). The electrode was left in place for a minimum of 7 days. Five patients were successively implanted with a permanent sacral electrode with a stimulation frequency of 16 to 18 Hz and amplitude of 1.1–4.9 V. RESULTS: Seventeen of the 19 patients (89.4 percent) who completed the minimum percutaneous nerve evaluation period of 7 days (median 10.7 (range 7–30)), had a reduction of liquid or solid stool incontinence by more than 50 percent, and fourteen (73.6 percent) were completely continent for stool. The most important changes revealed by manovolumetry were an increase in resting pressure (P<0.001) and voluntary contraction (P=0.041), reduction of initial pressure for first sensation (P=0.049) and urge to defecate (P=0.002), and a reduction of the rectal volume for urge sensation (P=0.006). The percutaneous nerve evaluation results were reproduced at a median follow-up of 19.2 months (range 5 to 37) in the 5 patients who received a permanent implant. CONCLUSIONS: Temporary stimulation of the sacral roots (percutaneous nerve evaluation) can be of help in those patients with fecal incontinence, and the results are reproduced with permanent implantation. The positive effect on continence seems to be derived from not only the direct efferent stimulation on the pelvic floor and the striated sphincter muscle, but also from modulating afferent stimulation of the autonomous neural system, inhibition of the rectal detrusor, activation of the internal anal sphincter, and modulation of sacral reflexes that regulate rectal sensitivity and motility.     

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<3 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.     

Unilateral Pudendal Neuropathy is Common in Patients with Fecal Incontinence

Purpose Pudendal neuropathy and fecal incontinence frequently coexist; however, the contribution of neuropathy is unknown. The pudendal nerve innervates the external anal sphincter muscle, anal canal skin, and coordinates reflex pathways. Lateral dominance or a dominantly innervating nerve and its subsequent damage may have major implications in the etiology and treatment of fecal incontinence. This study was designed to establish the prevalence of pudendal neuropathy, in particular a unilateral one, and to examine the impact on anorectal function. Methods A total of 923 patients (745 females; mean age, 52 (range, 17–92) years) with fecal incontinence were studied using endoanal ultrasonography, anorectal manometry, rectal sensation, and pudendal nerve terminal motor latencies. Results A total of 520 patients (56 percent) demonstrated a pudendal neuropathy, which was unilateral in 38 percent (351 patients; 169 right-sided, 182 left-sided). Neuropathy, whether it was bilateral (bilateral vs. normal; 56 (range, 7–154) cm H₂O) vs. 67 (range, 5–215) cm H₂O; P < 0.01) or unilateral (unilateral vs. normal; 61 (range, 0–271) cm H₂O vs. 67 (range, 5–215) cm H₂O; P = 0.04) was associated with reduced anal resting tone. This also was seen with respect to squeeze increments (bilateral vs. normal; 34 (range, 0–207) cm H₂O vs. 52 (range, 0–378) cm H₂O; P < 0.001, unilateral vs. normal; 41 (range, 0–214) cm H₂O vs. 52 (range, 0–378) cm H₂O; P < 0.01). In those with intact sphincters, unilateral neuropathy was associated with reduced squeeze increments (unilateral vs. normal; 60 (range, 10–286) cm H₂O vs. 69 (range, 7–323) cm H₂O; P = 0.01) but no significant reduction in resting pressures. There was no association between pudendal neuropathy and abnormal rectal sensitivity. Conclusions Unilateral pudendal neuropathy is a common abnormality in individuals with fecal incontinence and is significantly associated with both attenuated resting pressures and squeeze increments. Although there are limitations in the interpretation of pudendal nerve terminal motor latencies, this study demonstrates that further exploration of the concept of lateral dominance is needed. Supported by a grant from Dunhill Medical Trust/Royal College of Surgeons. Poster presentation at the meeting of The American Society of Colon and Rectal Surgeons, Seattle, Washington, June 3 to 7, 2006. Reprints are not available.     

Results of neurophysiologic evaluation in fecal incontinence

PURPOSE: Several methods of neurophysiologic assessment exist in the investigation of patients with fecal incontinence. However, the clinical significance of the information gained is uncertain. The aim of this prospective study was to evaluate the results of pudendal nerve terminal motor latency and fiber density in relation to clinical variables and manometric measurements. METHODS: Seventy-two patients with fecal incontinence (63 women; mean age, 62; range, 24–81 years) responded to a bowel questionnaire and underwent anorectal manovolumetry, anal ultrasonography, defecography, and electromyography, including pudendal nerve terminal motor latency and fiber density. RESULTS: Pudendal neuropathy (pudendal nerve terminal motor latency >2.5 ms) was found in 46 percent and increased fiber density (>1.7) in 82 percent. Pudendal neuropathy and increased fiber density were most common in patients with rectal prolapse or intra-anal intussusception. No difference was seen concerning anal resting and incremental pressures, rectal compliance, rectal sensibility or severity of incontinence in patients with unilateral, bilateral, or marked (>4 ms) pudendal neuropathyvs. patients with normal pudendal nerve terminal motor latency. In contrast, patients with increased fiber density had lower incremental pressures (P<0.05) and stated decreased rectal sensibility (P<0.05) compared with those with normal fiber density. These differences were most pronounced in patients with neurogenic or idiopathic incontinence. CONCLUSIONS: Pudendal neuropathy and increased fiber density are common in patients with fecal incontinence. Fiber density but not pudendal nerve terminal motor latency was correlated with clinical and manometric variables. The severity of nerve injury correlated with anal motor and sensory function in patients with neurogenic or idiopathic incontinence. The routine use of pudendal nerve terminal motor latency in the assessment of patients with fecal incontinence can be questioned.Read at The American Society of Colon and Rectal Surgeons' 100th Anniversary and Tripartite Meeting, Washington, D.C., May 1 to 6, 1999.     

Preoperative Anal Manometry Predicts Continence After Perineal Proctectomy for Rectal Prolapse

Purpose This study examines whether preoperative anal manometry and pudendal nerve terminal motor latency predict functional outcome after perineal proctectomy for rectal prolapse. Methods All adult patients treated by perineal proctectomy for rectal prolapse from 1995 to 2004 were identified (N = 106). Forty-five patients underwent anal manometry and pudendal nerve terminal motor latency testing before proctectomy and they form the basis for this study. Results Perineal proctectomy with levatoroplasty (anterior 88.9 percent; posterior 75.6 percent) was performed in all patients, with a mean resection length of 10.4 cm. Four patients (8.9 percent) developed recurrent prolapse during a 44-month mean follow-up. Preoperative resting and maximal squeeze pressures were 34.2 ± 18.3 and 60.4 ± 30.5 mmHg, respectively. Pudendal nerve terminal motor latency testing was prolonged or undetectable in 55.6 percent of patients. Grade 2 or 3 fecal incontinence was reported by 77.8 percent of patients before surgery, and one-third had obstructed defecation. The overall prevalence of incontinence (77.8 vs. 35.6 percent, P < 0.0001) and constipation (33.3 vs. 6.7 percent, P = 0.003) decreased significantly after proctectomy. Patients with preoperative squeeze pressures >60 mmHg (n = 19) had improved postoperative fecal continence relative to those with lower pressures (incontinence rate, 10 vs. 54 percent; P = 0.004), despite having similar degrees of preoperative incontinence. Abnormalities of pudendal nerve function and mean resting pressures were not predictive of postoperative incontinence. Conclusions Perineal proctectomy provides relief from rectal prolapse, with good intermediate term results. Preoperative anal manometry can predict fecal continence rates after proctectomy, because patients with maximal squeeze pressures >60 mmHg have significantly improved outcomes. Supported exclusively using institutional funding. Presented at the meeting of The American Society of Colon and Rectal Surgeons, Philadelphia, Pennsylvania, April 30 to May 5, 2005.     

Rectal Hypersensitivity Worsens Stool Frequency, Urgency, and Lifestyle in Patients With Urge Fecal Incontinence

PURPOSE Rectal sensory mechanisms are important in the maintenance of fecal continence. Approximately 50 percent of patients with urge incontinence have lowered rectal sensory threshold volumes (rectal hypersensitivity) on balloon distention. Rectal hypersensitivity may underlie the heightened perception of rectal filling; however, its impact on fecal urgency and incontinence is unknown. This study was designed to investigate the impact of rectal hypersensitivity in patients with urge fecal incontinence.METHODS Prospective and retrospective audit review of all patients (n = 258) with an intact native rectum referred to a tertiary colorectal surgical center for physiologic investigation of urge fecal incontinence during a 7.5-year period. Patients with urge fecal incontinence who had undergone pelvic radiotherapy (n = 9) or rectal prolapse (n = 6) were excluded.RESULTS A total of 108 of 243 patients (44 percent) were found to have rectal hypersensitivity. The incidence of anal sphincter dysfunction was equal (90 percent) among those with or without rectal hypersensitivity. Patients with urge fecal incontinence and rectal hypersensitivity had increased stool frequency (P < 0.0001), reported greater use of pads (P = 0.003), and lifestyle restrictions (P = 0.0007) compared with those with normal rectal sensation, but had similar frequencies of incontinent episodes.CONCLUSIONS Urge fecal incontinence relates primarily to external anal sphincter dysfunction, but in patients with urge fecal incontinence, rectal hypersensitivity exacerbates fecal urgency, and this should be considered in the management and surgical decision in patients who present with fecal incontinence.Christopher L. H. Chan, F.R.C.S., is supported by a MRC Clinical Training Fellowship.     

Rectal compliance in the assessment of patients with fecal incontinence

Rectal compliance (dV/dP) was studied in 31 patients with fecal incontinence, 8 patients with constipation, and 16 control subjects. Patients with fecal incontinence experienced a constant defecation urge at a lower rectal volume and also had a lower maximal tolerable volume and a lower rectal compliance than control subjects (median 126 vs. 155 ml, 170 vs. 220 ml, and 9 vs. 15 ml/mm Hg, respectively;tP <0.05). Constipated patients had a higher constant defecation urge volume and maximal tolerable volume than controls (median, 266 ml and 300 ml;P <0.05). There was no differences in the parameters between patients with idiopathic fecal incontinence and patients with incontinence of traumatic origin, indicating that a poorly compliant rectum in patients with fecal incontinence may be secondary to anal incontinence due to the lack of normal reservoir function.Reprints will not be available.     

Rehabilitation of Fecal Incontinence After Sphincter-Saving Surgery for Rectal Cancer: Encouraging Results

Purpose  Some patients, having undergone sphincter-saving operations for rectal cancer, may suffer from fecal incontinence. This study was designed to evaluate the results of rehabilitative treatment in patients with fecal incontinence after sphincter-saving operations and to identify the negative factors that influence therapeutic success. Methods  Between January 2000 and June 2007, 88 incontinent patients (54 women; age range, 47–73 years; 69 had received a low anterior rectal resection; 19 a straight coloanal anastomosis) were included in the study. After a preliminary clinical evaluation, including the Wexner Incontinence Scale score, anorectal manometry was performed. All 88 patients underwent rehabilitative treatment according to the “multimodal rehabilitative program” for fecal incontinence. At the end of program, all 88 patients were reassessed by means of a clinical evaluation and anorectal manometry; their results were compared with the clinical and manometric data from ten healthy control subjects. Postrehabilitative Wexner Incontinence Scale scores were used for an arbitrary schedule of patients divided into three classes: Class I, good (score ≤3); Class II, fair (score >3 to ≤6); Class III, poor (score >6). Results  After rehabilitation, there was a significant improvement in the overall mean Wexner Incontinence Scale score (P < 0.03) for both surgical operation types (low anterior rectal resection: P < 0.05; coloanal anastomosis: P < 0.02). Only 21 patients (23.8 percent) were symptom-free, and 37 (42 percent) were considered Class III. A significant postrehabilitative direct correlation was found between: 1) Wexner Incontinence Scale score and degree of genital relaxation (rρ _s 0.78; P < 0.001); 2) Wexner Incontinence Scale score and irradiation (rρ _s 0.72; P < 0.01); and 3) Wexner Incontinence Scale score and pelvic (rρ _s 0.65; P < 0.01) or anal surgery (rρ _s 0.68; P < 0.01). No significant differences were found between prerehabilitative and postrehabilitative anal pressures in low anterior rectal resection and coloanal anastomosis patients. Conclusions  After rehabilitation, some patients become symptom-free, many patients show an improvement in the Wexner Incontinence Scale score, and others exhibit the highest grades of fecal incontinence. Genital relaxation, radiotherapy, and previous pelvic, and/or anal surgery are impeding factors to rehabilitative success.     

Evidence of electromechanical dissociation of the internal anal sphincter in idiopathic fecal incontinence

PURPOSE: This study was designed to evaluate the relationship between internal sphincter electromyographic frequency and ambulatory anal pressures in order to clarify the pathophysiology of internal anal sphincter dysfunction in fecal incontinence. METHODS: Seventytwo patients of median age 55 years (range, 24–75; 63 females) with neurogenic fecal incontinence and 33 normal subjects of median age 48.5 years (range, 25–74; 21 females) underwent fine-wire anal sphincter electromyography and anal manometry. RESULTS: The median internal anal sphincter electromyographic frequency was incontinent 0.25 Hz (0.2–0.34) and the control was 0.44 Hz (0.36–0.55;P<0.03). Ambulatory resting pressures were incontinent median 54 cm of H ₂ O (34–68 cm of H ₂ O) and control 94 cm of H ₂ O (72–102;P<0.01). Internal sphincter electromyographic frequency correlated with anal resting pressures in both groups (P<0.002). Internal sphincter electromyographic silence not attributable to electrode movement or the rectoanal inhibitory reflex, lasting 0.5 to 4 minutes occurred in all but two of the incontinent patients. The anal pressure during this period did not significantly change (P>0.1). No recruitment of the external sphincter or puborectalis was noted during these episodes. Such electromechanical dissociation was not seen in the control group. The frequency of transient internal sphincter relaxation was 4 (ranges 2–6) per hour in controls and 8 (ranges, 6–12) per hour in incontinent patients (P<0.01). Rectal pressures did not exceed midanal pressures in any of the controls but did in all of the incontinent patients on at least one occasion per hour in the incontinent group. CONCLUSION: Internal anal sphincter activity exhibits electromechanical dissociation and relaxes abnormally in incontinent patients.Supported by a separate equipment grant from the Scottish Hospital Endowment Research Trust.Read at the meeting of The American Society of Colon and Rectal Surgeons, San Francisco, California, June 7 to 12, 1992.     

Radio-frequency energy delivery to the anal canal for the treatment of fecal incontinence

PURPOSE: In this prospective study we investigated the feasibility, safety, and efficacy of radio-frequency energy delivery deep to the mucosa of the anal canal for the treatment of fecal incontinence. METHODS: We studied ten patients with fecal incontinence of varying causes. All patients underwent anoscopy, anorectal manometry, endorectal ultrasound, and pudendal nerve terminal motor latency testing at baseline and six months. The Cleveland Clinic Florida scale for fecal incontinence (Wexner, 0–20), fecal incontinence-related quality of life score, and Short Form 36 were administered at baseline, 1, 2, 3, 6, and 12 months. Using conscious sedation and local anesthesia, we delivered temperature-controlled radio-frequency energy via an anoscopic device with multiple needle electrodes to create thermal lesions deep to the mucosa of the anal canal. RESULTS: Ten females (age, 55.9 ± 9.2 years; range, 44–74) were enrolled and treated. Median discomfort by visual analog scale (0–10) was 3.8 during and 0.9 two hours after the procedure. Bleeding occurred in four patients (14–21 days after procedure), spontaneous resolution (n = 3) and anoscopic suture ligation (n = 1). At 12 months, the median Wexner score improved from 13.5 to 5 (P < 0.001), with 80 percent of patients considered responders. All parameters in the fecal incontinence-related quality of life were improved (lifestyle (from 2.3 to 3.4), coping (from 1.4 to 2.7), depression (from 2.2 to 3.5), and embarrassment (from 1.3 to 2.8); P < 0.05 for all parameters). Protective pad use was eliminated in five of the seven baseline users. At six months, there was a significant reduction in both initial and maximum tolerable rectal distention volumes. Anoscopy was normal at six months. CONCLUSION: Radio-frequency energy delivery to the anal canal for treatment of fecal incontinence is a new modality that, in this study group, safely improved Wexner and fecal incontinence-related quality of life scores, eliminated protective pad use in most patients, and improved patient quality of life.     

Paradoxical high anal resting pressures in men with idiopathic fecal seepage

PURPOSE: Fecal incontinence has been a matter of concern for many years, but seepage is poorly understood, especially in men. METHODS: We compared the results of anorectal physiologic tests in a group of 16 male patients who complained of fecal soiling but had no previous history of anorectal surgery or disease and had normal clinical examinations with findings of 16 normal male controls. Physical examination and proctosigmoidoscopy were normal in each patient. RESULTS: Maximum anal resting pressure (median interquartile range) was 136 (120–145) cm H₂O in the “seepage” group and 104 (83–112) cm H₂O in controls (P<0.01). Inflation volumes at which patients and controls experienced rectal sensation were 45 (35–80) and 90 (75–100) ml of air, respectively (P<0.01). Maximum tolerated volumess in the rectum were 130 (85–180) ml of air in the seepage group and 190 (140–240) ml of air in controls (P<0.01). Median length of the anal sphincter was 3.75 (3.5–4) cm in patients and 3 (3–3.5) cm in controls (P<0.01). Maximum squeeze pressures, sensation in the anal canal, and sphincter relaxation in response to rectal distention were similar in the two groups. CONCLUSION: Male patients with “idiopathic” fecal seepage have a long anal sphincter with abnormally high resting tone.     

Rectal compliance as a routine measurement

PURPOSE: The clinical impact of rectal compliance and sensitivity measurement is not clear. The aim of this study was to measure the rectal compliance in different patient groups compared with controls and to establish the clinical effect of rectal compliance. METHODS: Anorectal function tests were performed in 974 consecutive patients (284 men). Normal values were obtained from 24 controls. Rectal compliance measurement was performed by filling a latex rectal balloon with water at a rate of 60 ml per minute. Volume and intraballoon pressure were measured. Volume and pressure at three sensitivity thresholds were recorded for analysis: first sensation, urge, and maximal toleration. At maximal toleration, the rectal compliance (volume/pressure) was calculated. Proctoscopy, anal manometry, anal mucosal sensitivity, and anal endosonography were also performed as part of our anorectal function tests. RESULTS: No effect of age or gender was observed in either controls or patients. Patients with fecal incontinence had a higher volume at first sensation and a higher pressure at maximal toleration (P=0.03), the presence of a sphincter defect or low or normal anal pressures made no difference. Patients with constipation had a larger volume at first sensation and urge (P<0.0001 andP<0.01). Patients with a rectocele had a larger volume at first sensation (P=0.004). Patients with rectal prolapse did not differ from controls; after rectopexy, rectal compliance decreased (P<0.0003). Patients with inflammatory bowel disease had a lower rectal compliance, most pronounced in active proctitis (P=0.003). Patients with ileoanal pouches also had a lower compliance (P<0.0001). In the 17 patients where a maximal toleration volume<60 ml was found, 11 had complaints of fecal incontinence, and 6 had a stoma. In 31 patients a maximal toleration volume between 60 and 100 ml was found; 12 patients had complaints of fecal incontinence, and 6 had a stoma. Proctitis or pouchitis was the main cause for a small compliance. All 29 patients who had a maximal toleration volume>500 ml had complaints of constipation. No correlation between rectal and anal mucosal sensitivity was found. CONCLUSION: Rectal compliance measurement with a latex balloon is easily feasible. In this series of 974 patients, some patient groups showed an abnormal rectal visceral sensitivity and compliance, but there was an overlap with controls. Rectal compliance measurement gave a good clinical impression about the contribution of the rectum to the anorectal problem. Patients with proctitis and pouchitis had the smallest rectal compliance. A maximal toleration volume<60 ml always led to fecal incontinence, and stomas should be considered for such patients. A maximal toleration volume>500 ml was only seen in constipated patients, and therapy should be given to prevent further damage to the pelvic floor. Values close to or within the normal range rule out the rectum as an important factor in the anorectal problem of the patient.Drs. Sloots and Poen were supported by a grant from Janssen-Cilag. Presented at the meeting of the Dutch Society of Gastroenterology, Veldhoven, the Netherlands, October 7 to 8, 1999.     

Circadian rhythm of rectal motor complexes

PURPOSE: Prolonged rectal pressure recordings have revealed that the rectum exhibits typical bursts of regular pressure waves, also called rectal motor complexes. Although there is consensus regarding the characteristics of rectal motor complexes, their function is poorly understood. Furthermore, data regarding the circadian rhythm of these complexes are either lacking or conflicting. Therefore, we conducted a study to investigate the circadian rhythm of rectal motor complexes in fully ambulant subjects. Because a meal is a powerful and physiologic stimulus to elicit colonic pressure activity, we also studied the effect of a meal on these rectal motor complexes. METHODS: Prolonged ambulant anorectal pressure recordings were performed in 12 healthy volunteers (male:female ratio, 6:6; median age, 27 (range, 22–53) years). A total of 139 rectal motor complexes were observed in >300 hours of recording. RESULTS: All subjects exhibited rectal motor complexes during the daytime, whereas in five subjects, no rectal motor complexes were observed during sleep. The number of rectal motor complexes was significantly lower during sleep (diurnalvs. nocturnal, 8vs. 1 per subject,P<0.0001). Furthermore, the duration and peak amplitude of these nocturnal rectal motor complexes were significantly reduced. On the ambulant recordings, the subjects marked a total of 20 meals. During the first 2 hours after these meals, rectal motor complexes were noted in 65 percent of the cases. The postprandial frequency of rectal motor complexes was significantly higher than the overall frequency (2/hourvs. 0.4/hour,P=0.004). CONCLUSIONS: These findings suggest that sleep results in a reduction of rectal motor activity, whereas a meal provides a stimulus for increased rectal motor activity in fully ambulant subjects.     

Sacral Nerve Stimulation for Fecal Incontinence Related to Obstetric Anal Sphincter Damage

Purpose Sphincter repair is the standard treatment for fecal incontinence secondary to obstetric external anal sphincter damage; however, the results of this treatment deteriorate over time. Sacral nerve stimulation has become an established therapy for fecal incontinence in patients with intact sphincter muscles. This study investigated its efficacy as a treatment for patients with obstetric-related incontinence. Methods Fecally incontinent patients with external sphincter defects who would normally have undergone overlapping sphincter repair as a primary or repeat procedure were included. Eight consecutive women (median age, 46 (range, 35–67) years) completed temporary screening; all eventually had permanent implantation. Results Six of eight patients had improved continence at median follow-up of 26.5 (range, 6–40) months. Fecal incontinent episodes improved from 5.5 (range, 4.5–18) to 1.5 (range, 0–5.5) episodes per week (P = 0.0078). Urgency improved in five patients, with ability to defer defecation improving from a median of <1 (range, 0–5) minute to 1 to 5 (range, 1 to >15) minutes (P = 0.031, all 8 patients). There was no change in anal manometry or rectal sensation. There was significant improvement in lifestyle, coping/behavior, depression/self-perception, and embarrassment as measured by the American Society of Colon and Rectal Surgery fecal incontinence quality of life score. Conclusions Sacral nerve stimulation is potentially a safe and effective minimally invasive treatment for fecal incontinence in patients with de novo external anal sphincter defects or defects after unsuccessful previous external anal sphincter repair, although numbers remain small. Dr. Michael Kamm is a consultant to and received research support from Medtronic, however, study design, performance, analysis, and reporting have been conducted without the influence of Medtronic.     

Long-Term Anorectal Dysfunction After Postoperative Radiotherapy for Rectal Cancer

PURPOSE Adjuvant radiotherapy in the treatment of rectal cancer has been shown to increase long-term morbidity causing severe anorectal dysfunction with physiologic changes whose interaction remains poorly understood. This study examines long-term anorectal morbidity from adjuvant postoperative radiotherapy.METHODS In a prospective study, patients with Dukes B or C rectal carcinoma were randomized to postoperative radiotherapy or no adjuvant treatment after anterior resection. The long-term effect of radiotherapy on anorectal function in a subset of surviving patients was assessed from a questionnaire on subjective symptoms and from physiology laboratory evaluation and flexible sigmoidoscopy.RESULTS Twelve of 15 patients (80 percent) treated with radiotherapy had increased bowel frequency compared with 3 of the 13 patients (23 percent) who did not have radiation therapy (P = 0.003). The former group had loose or liquid stool more often (60 vs. 23 percent, P = 0.05), had fecal incontinence more often (60 vs. 8 percent, P = 0.004), and wore pad more often (47 vs. 0 percent, P = 0.004). They also experienced fecal urgency and were unable to differentiate stool from gas more often. Endoscopy revealed a pale and atrophied mucosa and telangiectasias in the irradiated patients. Anorectal physiology showed a reduced rectal capacity (146 vs. 215 ml, P = 0.03) and maximum squeeze pressure (59 vs. 93 cm H₂O, P = 0.003) in the radiotherapy group. Impedance planimetry demonstrated a reduced rectal distensibility in these patients (P < 0.0001).CONCLUSIONS Adjuvant postoperative radiotherapy after anterior resection causes severe long-term anorectal dysfunction, which is mainly the result of a weakened, less sensitive anal sphincter and an undistensible rectum with reduced capacity.     

Double-blind crossover study of sacral nerve stimulation for fecal incontinence

PURPOSE: Patients with fecal incontinence not amenable to simple repair may have to undergo major reconstructive surgery or resort to a stoma. Sacral nerve stimulation is an alternative approach that may diminish incontinence by altering sphincter and rectal motor function. This study is the first double-blind trial examining the effectiveness of this therapy. METHODS: Two patients with passive fecal incontinence who had been implanted for nine months with a permanent sacral nerve stimulator and electrode were studied using fecal incontinence diaries, anorectal physiological tests, and quality-of-life assessments (SF-36 health survey). The trial period consisted of two two-week periods, with the stimulator turned on for two weeks and off for two weeks. The main investigator and the patients were blinded to the status of the stimulator. RESULTS: There was a dramatic difference between the number and severity of episodes of incontinence when the stimulator was turned onvs. turned off (Patient 1, 20vs. 2 episodes; Patient 2, 4vs. 0 episodes; offvs. on). There was an increase in squeeze pressure (Patient 1, 70vs. 100 cm H₂O; Patient 2, 60vs. 90 cm H₂O; offvs. on), with moderate increases in resting pressure and rectal threshold and urge volumes. Quality-of-life measurements showed a marked improvement prestimulationvs. nine months after permanent stimulation. CONCLUSIONS: There is a marked, unequivocal improvement in symptoms of fecal incontinence with sacral nerve stimulation shown in this double-blind crossover trial. Sacral nerve stimulation improves the quality of life in selected patients with fecal incontinence.A grant and all the equipment used in this study were supplied by Medtronic INTERSTIM, Maastricht, the Netherlands.     

Comparative analysis of late functional outcome following preoperative radiation therapy or chemoradiotherapy and surgery or surgery alone in rectal cancer

Purpose

This study evaluates the anorectal and genitourinary function of patients treated by preoperative short-term radiotherapy (RT) or chemoradiotherapy (CRT) followed by surgery and surgery alone for rectal cancer.

Methods

For this study, a total of 613 patients, who were identified from a prospective rectal cancer database, underwent anterior resection of the rectum between October 2001 and December 2007. Standardized questionnaires were used to determine fecal incontinence, urinary, and sexual function. Relevant clinical variables were evaluated using univariate and multivariate analyses. Independent predictors of functional outcome were identified by a binary logistic regression analysis.

Results

The data of 263 (43 %) patients were available for analysis. On multivariate analysis, neoadjuvant RT (P?<?0.01) and low anterior resection (LAR) (P?=?0.049) were associated with fecal incontinence. In univariate analysis, fecal incontinence was linked to preoperative neoadjuvant treatment (RT and/or CRT vs. LAR) (P?<?0.01). The hazard ratio for developing fecal incontinence was 3.3 (1.6–6.8) for patients who received RT. One hundred twenty-five patients (51.2 %) experienced urinary incontinence following surgery, the majority of whom were female (P?<?0.01). On univariate analysis, male sexual function was associated with age (P?<?0.01), ASA class (P?=?0.01) and LAR (P?=?0.01).

Conclusion

Multimodal therapy of low rectal cancer increases the incidence of fecal incontinence and negatively affects sexual function. The potential benefits of RT or CRT need to be balanced against the risk of increased bowel dysfunction when determining the appropriate treatment for individual patients with rectal cancer.     

Short-term sacral nerve stimulation for functional anorectal and urinary disturbances: results in 40 patients: evaluation of a new option for anorectal functional disorders

PURPOSE: There are several options in the treatment of fecal incontinence; it is often difficult to choose the most appropriate, adequate treatment. The consolidated experience gained in the urologic field suggests that sacral nerve stimulation may be a further option in the choice of treatment. The aim of our study was to evaluate the preliminary results of the peripheral nerve evaluation test obtained in a multicenter collaborative study on patients with defecatory and urinary disturbances. METHODS: Forty patients (9 males; mean age, 50.2; range, 26–79 years) underwent the peripheral nerve evaluation test, 28 (70 percent) for fecal incontinence and 12 (30 percent) for chronic constipation. Fourteen (35 percent) patients also had urinary incontinence; six had urge incontinence, two had stress incontinence, and six had retention incontinence. Associated diseases were scleroderma (2 patients), spinal injuries (4 patients), and syringomyelia (1 patient). All the patients underwent preliminary investigations with anorectal manometry, pudendal nerve terminal motor latency testing, anal ultrasound, defecography, and if required, urodynamic tests. The electrode for sacral nerve stimulation was positioned percutaneously under local anesthesia in the S2 (4), S3 (34), or S4 (1) foramen unilaterally (1 patient not accounted for because of no response to acute test), based on the best motor and subjective responses of paresthesia of the pelvic floor. Stimulation parameters were average amplitude, 2.8 (range, 1–6) V and average frequency, 15 to 25 Hz. RESULTS: The mean duration of the tests was 9.9 (range, 7–30) days; tests lasting fewer than seven days were not evaluated. There were four early displacements of the electrode. In 22 of the 25 evaluable patients with fecal incontinence, there was an improvement of symptoms (88 percent), and 11 (44 percent) were completely continent to liquid or solid stools, whereas in 7 symptoms were unchanged. Mean number of episodes of liquid or solid stool incontinence per week was 8.1 (range, 4–18) in the prestimulation period and 1.7 (range, 0–12) during the peripheral nerve evaluation test. (P=0.001; Wilcoxon's signed-rank test). The most important manometric findings were: increase of maximum rest pressure (39.4 ± 7.3vs. 54.3 ± 8.5 mmHg;P=0.014, Wilcoxon's test) and maximum squeeze pressure (84.7 ± 8.8vs. 99.5 ± 1.1 mmHg;P=0.047), reduction of initial threshold (63.6 ± 5.2vs. 42.4 ± 4.7 ml;P=0.041) and urge sensation (123.8 ± 0.6vs. 78.3 ± 8.9 ml;P=0.05). An improvement was also found in patients with constipation, with reduction in difficulty emptying the rectum, with prestimulation at 7 (range, 2–21) episodes per week and end of peripheral nerve evaluation test at 2.1 (range, 0–6) episodes per week, (P<0.01) and in the number of unsuccessful visits to the toilet, which dropped from 29.2 (7–24) to 6.7 (0–28) per week (P=0.01). The most important manometric findings in constipated patients were an increase in amplitude of maximum squeeze pressure during sacral nerve stimulation (prestimulation, 63 ± 0 mm Hg; end of peripheral nerve evaluation test, 78 ± 1 mm Hg;P=0.009) and a reduction in rectal volume for urge threshold (prestimulation, 189 ± 52 ml; end of peripheral nerve evaluation test, 139 ± 45 ml;P= 0.004). CONCLUSIONS: In functional bowel disorders short-term sacral nerve stimulation seems to be a useful diagnostic tool to assess patients for a minor invasive therapy alternative to conventional surgical procedure.Read at the meeting of The American Society of Colon and Rectal Surgeons, Boston, Massachusetts, June 24 to 29, 2000.