Treatment of anismus in intractable constipation with botulinum A toxin

Botulinum Toxin for the Treatment of Genital Pain Syndromes

Our purpose was to test the effect of botulinum toxin injections on hypertonic pelvic floor muscles of patients suffering from genital pain syndromes. We report two cases of women complaining of a genital pain syndrome resistant to pharmacological therapies and rehabilitation exercises associated with a documented involuntary tonic contraction of the levator ani muscle as a defense reaction triggered by vulvar pain. We performed botulinum toxin injections into the levator ani with the intent to relieve pelvic muscular spasms. Within a few days after the injections both the patients reported a complete resolution of the painful symptomatology, lasting for several months. Our experience suggests that botulinum injections are indicated in patients with genital pain syndrome with documented pelvic muscle hyperactivity, whose symptoms arise not only from genital inflammation and lesions, but also, and sometimes chiefly, from levator ani myalgia.

Treatment with botulinum neurotoxin of gastrointestinal smooth muscles and sphincters spasms

Local injections of botulinum neurotoxin are now considered an efficacious treatment for neurological and non-neurological conditions. One of the most recent achievements in the field is the observation that botulinum neurotoxin provides benefit in diseases of the gastrointestinal tract. Botulinum neurotoxin inhibits contraction of gastrointestinal smooth muscles and sphincters; it has also been shown that the neurotoxin blocks cholinergic nerve endings in the autonomic nervous system, but it does not block nonadrenergic responses mediated by nitric oxide. This aspect has further promoted the interest to use botulinum neurotoxin as a treatment for overactive smooth muscles, such as the anal sphincters to treat anal fissure and outlet-type constipation, or the lower esophageal sphincter to treat esophageal achalasia. Knowledge of the anatomical and functional organization of innervation of the gastrointestinal tract is a prerequisite to understanding many features of botulinum neurotoxin action on the gut and the effects of injections placed into specific sphincters. This review presents current data on the use of botulinum neurotoxin to treat diseases of the gastrointestinal tract and summarizes recent knowledge on the pathogenesis of disorders of the gut due to a dysfunction of the enteric nervous system.

Pilot study of botulinum toxin type A in the treatment of chronic pelvic pain associated with spasm of the levator ani muscles

OBJECTIVE

To investigate whether botulinum toxin type A (BOTOX) injected into the levator ani muscles of women with objective pelvic floor muscle spasm decreases pain symptoms and improves quality of life.

DESIGN

A prospective cohort study.

SETTING

Outpatient clinic in a tertiary referral centre, Sydney, Australia.

SAMPLE

Twelve women, aged 18-55 years, with objective pelvic floor muscle hypertonicity and a minimum 2-year history of chronic pelvic pain were recruited.

METHODS

All women completed visual analog scale pain assessments; questionnaires relating to bladder and bowel symptoms and quality of life; and specific examinations. Forty units of BOTOX at three different dilutions were given bilaterally into the puborectalis and pubococcygeus muscles under conscious sedation.

RESULTS

Median visual analog scale scores were significantly improved for dyspareunia (80 vs 28; P=0.01) and dysmenorrhea (67 vs 28; P=0.03), with non-significant reductions in non-menstrual pelvic pain (64 vs 37) and dyschesia (47 vs 29). Pelvic floor muscles manometry showed a 37% reduction in resting pressure at week 4 and a 25% reduction was maintained at week 12 (P <0.0001). Quality of life scores (EQ-5D and SF-12) were improved from baseline at week 12, but did not reach statistical significance. Sexual activity scores were markedly improved, with a significant reduction in discomfort (4.8 vs 2.2; P=0.02) and improvement in habit (0.2 vs 1.9; P=0.03). These results were not influenced by dilution.

CONCLUSION

There is evidence from the present pilot study suggesting that women with pelvic floor muscles hypertonicity and pelvic pain may respond to BOTOX injections into the pelvic floor muscles. Further research into this novel treatment of chronic pelvic pain is strongly recommended.

Constipation caused by functional outlet obstruction

Functional constipation is a very common problem in Western societies. Functional outlet obstruction, part of the spectrum of functional constipation, is suspected when patients present with select symptoms. Diagnosis is commonly made with anorectal manometry, electromyography, and rectal evacuation tests. Abnormal test patterns include poor relaxation and contraction of the anal sphincter in response to attempted defecation and difficult rectal evacuation. Several treatment approaches have been tested in these patients. Biofeedback training is considered the most specific therapeutic modality, and it is particularly attractive because of its safety. This review provides an assessment of the diagnostic tests for functional outlet obstruction and summarizes current options for therapy.

Internal anal sphincter achalasia in children: clinical characteristics and treatment with Clostridium botulinum toxin

OBJECTIVES

To describe the clinical characteristics of children with internal anal sphincter (IAS) achalasia and to evaluate the benefit of intrasphincteric injection of Clostridium botulinum toxin.

METHODS

Retrospective review of the medical records of 20 patients (8 male, mean 5.8 +/- 4.2 years) with severe chronic constipation and IAS achalasia. Each patient received four-quadrant, intrasphincteric injections of botulinum toxin at a dose of 15-25U per quadrant. Patients were reassessed 4 weeks-18 months after injection. We compared the clinical characteristics of these patients to 20 consecutive children (14 male, mean age 8.1 + 4.6 y) with functional constipation (control group).

RESULTS

The children with IAS achalasia had earlier onset of symptoms, less fecal soiling, and less withholding behavior than the control children. Response to botulinum injection was rated excellent by the parents in 60% and by the physician in 35% of children. There was wide individual variability in the frequency of defecation after therapy. Duration of response ranged from 1 week to 18 months.

CONCLUSIONS

Children with IAS achalasia have clinical characteristics differentiating them from children with functional constipation. Intra-anal injection of botulinum toxin is a safe and effective short-term treatment for these children.

[Digestive tract and botulinum toxin]

INTRODUCTION

the aim of this work was to check literature to assess botulinum toxin injection efficacy in gastrointestinal motor disorders with special emphasis on controlled clinical trials.

METHODS

literature was carried out with the Medline data bank.

RESULTS

seventy three articles in French and in English including a recent general review were retained. Comparative clinical trials only concerned achalasia and anal fissure. The other gastrointestinal motor disorders only gave rise to open non-controlled trials assessed on clinical end points.

DISCUSSION

this review of literature helps to determine usefulness and safety of Botulinum toxin injection in the treatment of esophageal achalasia and anal fissure. The main limitation is its brief duration of action. Studies concerning the others spastic motor disorders are based on unknown physiopathology and controlled trials are required to assess its efficacy.

CONCLUSION

botulinum toxin is increasingly used for gastrointestinal motor disorders with worthwhile results. Its efficacy has been yet established for only two disorders : it has a valuable palliative role in achalasia and may be curative for anal fissure.

Efficacy of reconstituted and stored botulinum toxin type A: an electrophysiologic and visual study in the auricular muscle of the rabbit

Once botulinum toxin type A is reconstituted, the manufacturer recommends that it be used in approximately 4 hours. As a result, a significant amount of this costly drug is often discarded because it is not completely used in the recommended period. The purpose of the present study was to compare fresh versus stored reconstituted botulinum toxin type A for (1) initial potency, (2) duration of action, and (3) bacterial colonization. Using a rabbit model, 20 New Zealand White rabbits were divided into four groups (I to IV). All rabbits had an injection of 2.5 U of reconstituted botulinum toxin into the right anterior auricular muscle. The first group was injected with botulinum toxin type A that was freshly reconstituted and served as the control. The second, third, and fourth groups were injected with botulinum toxin type A that had been reconstituted and stored for 2, 6, and 12 weeks, respectively, in a conventional freezer. Each rabbit had daily visual evaluation of the ear, with the position of auricle being graded from I to III. In addition, each rabbit had a nerve conduction study performed on the right anterior auricular muscle before injection and every 2 weeks after injection. Amplitude was chosen as the principal variable in the data analysis because it is the best predictor of physiologic changes at the muscle motor unit level. The endpoint of the study was defined as the time at which the nerve conduction studies and the visual inspections returned to baseline, preinjection levels. Botulinum toxin type A was also cultured before injection into each group.Overall, the nerve conduction data revealed a trend with a faster recovery (return to baseline) with the stored botulinum toxin. Groups IV and III returned to baseline first, followed by groups II and I. However, there was no significant difference among the groups at 2 and 4 weeks after injection, indicating that initial potency was unchanged. The differences between the groups became significant (p < 0.05) at 6 weeks and onward, suggesting that the duration was affected. Group I (fresh botulinum toxin) and group II (toxin stored for 2 weeks) had comparable outcomes and were not significantly different at any time period. Under visual inspection, the mean recovery time for each group was as follows: group IV, 5.4 weeks; group III, 7.0 weeks; group II, 6.75 weeks; and group I, 7.80 weeks. The results showed significance (p < 0.05) beginning after 3 weeks among some groups. Again, there was an overall quicker trend to return to baseline with the longer storage of the botulinum toxin (groups III and IV). These results support the authors' conduction study data, which suggest that the initial potency is not affected but the duration of action is. Again, groups I and II had comparable results. Microbiology cultures showed no growth of either aerobic or anaerobic bacteria at 7 days. In conclusion, using the rabbit model, it seems that reconstituted and stored botulinum toxin type A has the same initial potency but the duration of action is affected sometime after 2 weeks of storage. No bacterial contamination was associated with storing unpreserved reconstituted botulinum toxin type A for up to 12 weeks.

Constipation: evaluation and treatment

Constipation is a common clinical problem that comprises a constellation of symptoms that include excessive straining, hard stools, feeling of incomplete evacuation, use of digital maneuvers, or infrequent defecation. Although many conditions, such as metabolic problems, fiber deficiency, anorectal problems, and drugs, can cause constipation, when excluded functional constipation consists of two subtypes: slow-transit constipation and dyssynergic defecation. Some patients with irritable bowel syndrome may exhibit features of both types of constipation. The Rome criteria for functional constipation together with modifications proposed here for dyssynergic defecation may serve as useful guidelines for making a diagnosis. Recent advances in technology, together with a better understanding of the underlying mechanisms, have led to real progress in the diagnosis of this condition. Management options are limited, however, and evidence to support these treatments is only modest. The treatment is primarily medical; surgical options should be reserved for refractory disease and after careful diagnostic work-up. Although laxatives remain the mainstay of therapy, prokinetics that are colon-selective are optimal for treating patients with slow-transit constipation, but they are not yet available for clinical use. Recent controlled trials, however, are promising. Biofeedback therapy is the preferred treatment for patients with dyssynergia, but is not widely available. In the near future, user-friendly biofeedback programs including home therapy may facilitate wider use of these methods for patients with dyssynergic defecation.

New approaches to the treatment of anal fissure

According to Antropoli, pathologies of the anal canal are extremely common. About 30 to 40 percent of the population suffers from proctologic pathologies at least once in their lives. In most cases they are more annoying than dangerous. Anal fissure (AF) was recognized as a clinical entity in 1934. It is a longitudinal defect of the anal canal mucosa and anoderm extending usually from the dentate line to the external verge of the anal canal. This defect exposes the lower half or even most of the fibres of internal anal sphincter. AF is almost always accompanied by extensive tension of this muscle. Anal fissures affect all age groups but predominantly occur in the 3rd and 4th decades of life (2, 8, 23). Gathright states that fissure disease causes from 6 to 15% of office visits and 10% of operative procedures in a colorectal practice. The etiology of anal fissure has only been partially explained and remains controversial although spasm of the internal anal sphincter has been recognized to play a main role in the pathogenesis of this disease. Recent studies have cast new light on the pathogenesis of anal fissures.

Side effects of botulinum toxin injection for benign anal disorders

BACKGROUND

Botulinum toxin A (BT-A) is a powerful biological toxin. Nevertheless, it has proved to be a remarkable therapeutic agent for the treatment of benign anal disorders. Higher doses of BT-A could change the outcome of treatment. It is not known whether doses of BT-A higher than 20 units of Botox (or corresponding doses of Dysport) are as safe for patients as lower doses of BT-A.

METHODS

The side effects of BT-A injections in the treatment of chronic anal fissure (105 patients) and functional outlet obstruction (34 patients) were analysed prospectively. The patients received at least 25 units of Botox or 150 units of Dysport.

RESULTS

The patients with chronic anal fissure complained of incontinence of flatus (one severe case and eight mild cases), incontinence of faeces (five mild cases), anal haematoma (five cases), flu-like syndrome (three cases), an acute inflammation of external anal varices (two cases), epididymitis (one case) and haemorrhoid prolapse (one case). Patients with anismus suffered from intertrigo (one case); the pain after injection lasted for 2-4 days (four cases). No life-threatening side effects after 181 injections of BT-A were observed. Most of the side effects were only transient symptoms. No significant interdependence between injection methods (injection into one or two sites) and the risk of side effects was found.

CONCLUSION

Treatment with BT-A is safe. Despite the application of higher doses of BT-A in the treatment of benign anal disorders so far, no severe side effects were observed.

Botulinum neurotoxin and other treatments for fissure-in-ano and pelvic floor disorders

BACKGROUND

The management of disorders of the lower gastrointestinal tract, such as chronic anal fissure and pelvic floor dysfunction, has undergone re-evaluation recently. To a large extent this is due to the advent of neurochemical treatments, such as botulinum neurotoxin injections and topical nitrate ointment.

METHODS AND RESULTS

This review presents, inter alia, current data on the use of botulinum neurotoxin to treat lower gastrointestinal tract diseases, such as chronic anal fissure for which it promotes healing and symptom relief in up to 70 per cent of cases. This agent has also been used selectively to weaken the external anal sphincter and puborectalis muscle in constipation and in Parkinson's disease. Symptomatic improvement can also be induced in anterior rectocele by botulinum neurotoxin injections.

CONCLUSION

Botulinum neurotoxin appears to be a safe therapy for anal fissure. It is more efficacious than nitrate application and does not require patient compliance to complete treatment. While it may also be a promising approach for the treatment of chronic constipation due to pelvic floor dysfunction, further investigation of its efficacy and safety in this role is needed before general usage can be advocated.

Gastrointestinal uses of botulinum toxin

Botulinum toxin was initially used in medicine to produce a potent neuromuscular blockade. It was later found to interfere with acetylcholine release in the myenteric plexus and inhibit contraction in gastrointestinal smooth muscle, leading to its use in the treatment of various conditions. It is frequently used in the treatment of achalasia in elderly patients who may be poor surgical candidates. It has been used successfully in the management of various conditions, including anal fissure and biliary dyskinesia. Large controlled trials are needed to establish the role of botulinum toxin and its safety in gastroenterology.

Sacral magnetic stimulation in puborectalis paradoxical syndrome

BACKGROUND AND PURPOSE

Our earlier studies have demonstrated that sacral magnetic stimulation (MS) in the canine model, in healthy volunteers and in constipated subjects effected rectal pressure rise, decline of the rectal neck (anal canal) pressure as well as rectal evacuation. Based on these results, we studied the effect of sacral MS on defecation in patients with puborectalis paradoxical syndrome (PPS).

METHODS

Eleven subjects (8 women, 3 men; age 36-53 years) with PPS were enrolled in the study. The magnetic coil was placed on the back with its center located between L4 and L5. Stimulation parameters were set at 70% of maximum intensity, 40 Hz frequency and 2-second burst length with 2 seconds off. During MS, the rectal neck and gastric (intra-abdominal) pressures were measured. The procedure was performed in the empty and in the full rectum using the balloon expulsion test in the latter.

RESULTS

MS of the empty and balloon-filled rectum effected rise of the rectal pressure (p < 0.001), decline of the rectal neck pressure (p > 0.001) and no significant change of the intragastric pressure (p > 0.05). The balloon was expelled to the exterior in all the patients.

CONCLUSIONS

Sacral MS succeeded in dispelling to the exterior the water-filled rectal balloon. The method is simple, easy, non-invasive, non-radiologic and can be performed on an outpatient basis for the treatment of PPS.

Progress in the understanding and treatment of chronic anal fissure

BACKGROUND

Chronic anal fissure is a common and painful condition associated with internal anal sphincter hypertonia. Reduction of this hypertonia improves the local blood supply, encouraging fissure healing. Surgical sphincterotomy is very successful at healing these fissures but requires an operation with associated morbidity. Temporary reduction in sphincter tone can be achieved on an outpatient basis by applying a topical nitric oxide donor (for example, glyceryl trinitrate) or injecting botulinum toxin into the anal sphincter.

METHODS

A Medline database was used to perform a literature search for articles relating to the non-surgical treatment of chronic anal fissure.

RESULTS

Review of the literature shows botulinum toxin injection to be more effective at healing chronic anal fissures than topical glyceryl trinitrate. Topical isosorbide dinitrate has not been directly compared with either of these two agents but has a healing rate approaching that of botulinum toxin injection. The main side effect of botulinum toxin injection is temporary faecal incontinence in approximately 2% of cases, whereas topical nitrates cause headaches in 20%-100% of cases. No long term side effects were identified with any of the medical treatments.

CONCLUSION

Chemical sphincterotomy is an effective treatment for chronic anal fissure and has the advantages over surgical treatment of avoiding long term complications (notably incontinence) and not requiring hospitalisation.

Botulinum toxin type-A in therapy of patients with anismus

INTRODUCTION

Anismus is a common cause of constipation and outlet obstruction. Standard therapy with laxatives or biofeedback has conflicting results. Surgical treatment gives poor results and has practically been abandoned.

PURPOSE

This study was designed to evaluate the efficacy of botulinum toxin type-A (Botox) injection to the puborectalis muscle in patients with anismus.

METHODS

Twenty-five patients (15 females; mean age, 23.2) with history of constipation and symptoms of outlet obstruction underwent anorectal perfusion manometry and video-proctography. All patients were found to have a nonrelaxing puborectalis muscle on both modalities. All have been unable to expel a rectal balloon. Each patient who participated in the study was randomly assigned to undergo local injection of Botox--10 units to each side of the puborectalis or 20 units to the posterior aspect of this muscle. Eight patients underwent further injections1-5 every 3 months in accordance with previous results. Follow-up was conducted 1, 4, 12, and 24 weeks after injection. Straining, anorectal pain, and overall satisfaction were assessed on a visual analog scale. Weekly evacuation, fecal incontinence, and complications were recorded. At the weekly meeting, each patient underwent anorectal manometry with a balloon expulsion test.

RESULTS

Manometric relaxation was achieved after the first injection in 18 patients (75 percent). Once relaxation was achieved, it lasted throughout the follow-up. Nine patients (37.5 percent) expelled the rectal balloon after the first injection. Seven of 16 patients who failed the first injection had an additional one. In 2 patients it was successful (28.6 percent). Symptom improvement of 29.2 percent in straining index was recorded during follow-up. In 3 patients (12.5 percent) pain developed after injection. No other complications were observed. Overall satisfaction with Botox injection results was observed in 58.3 percent.

CONCLUSIONS

Botox injection to the puborectalis muscle has been found to have a limited therapeutic effect on patients suffering from anismus. Our results justify the need for further double-blind placebo-controlled trials to determine the exact role of botulinum toxin type-A in anismus.

Treatment of proctalgia fugax with botulinum A toxin

Two recent studies described a temporal association between a high-amplitude and high-frequency myoelectrical activity of the anal sphincter and the occurrence of proctalgia, which suggest that paroxysmal hyperkinesis of the anus may cause proctalgia fugax. We describe a single case of proctalgia fugax responding to anal sphincter injection of Clostridium botulinum type A toxin. The presumed aetiology of proctalgia fugax is discussed and the possible mechanism of action of botulinum toxin (BTX) in this condition is outlined. Botulinum A toxin seems to be a promising treatment for patients with proctalgia fugax, and further trials appear to be worthwhile for this condition, which has been described as incurable.

Outlet Dysfunction Constipation

The diagnosis of outlet dysfunction constipation in patients with idiopathic constipation that responds poorly or not at all to conservative measures, such as fiber supplements, fluids, and stimulant laxatives, is based upon diagnostic testing. These tests include colonic transit of radio-opaque markers, anorectal manometry or electromyography, barium defecography, and expulsion of a water-filled balloon. The literature suggests that conditions such as pelvic floor dyssynergia exist but may be over-diagnosed as a laboratory artifact. In our laboratory, we screen patients with balloon expulsion studies, and then test for dyssynergia only if the result of the balloon expulsion test is abnormal. In my opinion, anal sphincter electromyogram and manometry are equivalent in establishing the diagnosis. Barium defecography is helpful in making a diagnosis of a rectocele, but I prefer to document that vaginal pressure on the rectocele significantly improves rectal evacuation. Manometry also helps to establish the presence of megarectum, hypotonia, and weak expulsion efforts. Conceptually, biofeedback training, which incorporates simulated defecation, is the most logical approach to pelvic floor dyssynergia. It incurs no risk and benefits 60% to 80% of patients. The drawbacks are the time-intensive nature of the therapy and the short-term costs, which are offset if there is sustained benefit. There is no evidence that biofeedback is helpful in children with constipation. Habit training has established benefits, but recurrences are frequent and long-term reinforcement is helpful to maintain success. Laxatives and enemas are adjunctive therapies in both habit training and biofeedback. Surgery is effective in those uncommon patients with physiologically significant rectoceles, but surgical division of the puborectalis muscle is risky and unproven. Likewise, botulinum toxin injection into the puborectalis is unproven, but the effects are rarely permanent should incontinence occur. Diagnostic measures and therapeutic success are enhanced when patients are seen in centers experienced with the evaluation of these disorders.

Anterior rectocele due to obstructed defecation relieved by botulinum toxin

Background. Surgical repair of rectocele does not always alleviate symptoms related to difficulty in defecation, and some patients have impaired fecal continence after surgical treatment. To avoid complications of surgical repair, we investigated the efficacy of botulinum toxin in treating patients with symptomatic rectocele. Methods. Fourteen female patients with anterior rectocele were included in the study. The patients were studied by using anorectal manometry and defecography, and then treated with a total of 30 units of type A botulinum toxin, injected into 3 sites, 2 on either side of the puborectalis muscle and the third anteriorly in the external anal sphincter, under ultrasonographic guidance. Results. After 2 months, symptomatic improvement was noted in 9 patients (P =.0003). At the same time, rectocele depth (mean +/- SD) was reduced from 4.3 +/- 0.6 cm to 1.8 +/- 0.5 cm (P =.0000001) and rectocele area from 9.2 +/- 1.3 cm(2) to 2.8 +/- 1.6 cm(2) (P =.0000001). Anorectal manometry demonstrated decreased tone during straining from 70 +/- 28 mm Hg at baseline to 41 +/- 19 mm Hg at 1 month (P =.003) and to 41 +/- 22 mm Hg at 2 months (P =.005). No permanent complications were observed in any patient for a mean follow-up period of 18 +/- 4 months. At 1 year evaluation, incomplete or digitally assisted rectal voiding was not reported by any patient, and a rectocele was not found at physical examination. Four recurrent, asymptomatic rectoceles were noted at defecography. Conclusions. Botulinum toxin injections should be considered as a simple therapeutic approach in patients with anterior rectocele. The treatment is safe and less expensive than surgical repair. A more precise method of toxin injections under transrectal ultrasonography accounts for the high success rate. Repeated injections may be necessary to maintain the clinical improvement.

Chronic idiopathic anal pain: analysis of ultrasonography, pathology, and treatment

PURPOSE

This study was undertaken to analyze whether intra-anal ultrasound examination, anorectal physiologic evaluation, and histopathologic examination in patients with chronic idiopathic anal pain presented any common features and whether the results of different treatment modalities correlated with these findings.

METHODS

Eighteen patients who met the criteria for chronic idiopathic anal pain were studied. All had an intra-anal ultrasound examination and a complete anorectal physiologic evaluation. In a selected group of patients, ultrasound-guided biopsy samples were taken from pathological areas in the internal and external sphincter. Treatment consisted of analgesics only in four patients, 0.2 percent nitroglycerin ointment in four, and ultrasound injection of botulin (botulinum toxin, Botox) into the intersphincteric space in nine. Two patients, including one who was previously treated with botulin, ultimately had a colostomy.

RESULTS

Four patients were managed satisfactorily on analgesic treatment under the guidance of the hospital's pain clinic. Nitroglycerin ointment resulted in temporary pain relief in one of four patients. Injection of botulin resulted in a permanent improvement in four patients, a temporary improvement in one patient, and no effect in four patients. Two patients had a colostomy, resulting in complete pain relief. The effect or lack of effect of nitroglycerin ointment and botulin was not related to changes in anal pressure.

CONCLUSION

Chronic idiopathic anal pain is a condition of unknown origin for which no proven therapy exists. As in other syndromes based on muscular dystonia, some patients may benefit from injection of botulin.

Indications and efficacy of botulinum toxin in disorders of the gastrointestinal tract

In recent years, botulinum toxin type A (BT) has been found to be effective in the treatment of various spastic disorders of smooth muscle in the upper and lower gastrointestinal tract. The short-term efficacy of intrasphincteric injection of BT in achalasia is now well established, however, because of the chronic nature of the disease, patients will require repeated injections at regular intervals. In contrast, after a single injection into the anal sphincter, BT has impressively high healing rate with minimal side effects. BT remains a novel therapeutic approach in a range of other gastrointestinal motility disorders including diffuse oesophageal spasm, sphincter of Oddi dysfunction and anismus, and the list of its indications is increasing. BT seems to be safe but as its long-term effects remain unestablished, it should be used with caution in younger patients. In this review we discuss the mechanism of action, indications, efficacy and side-effects of BT with its use in various areas of gastrointestinal tract.

Dyssynergic defecation

Dyssynergic defecation is a common clinical problem that affects half of patients with chronic constipation. In many patients, there is a significant overlap with slow transit constipation. The chief underlying pathophysiologic mechanism is a failure of rectoanal coordination. By using a combination of history, prospective stool diaries, detailed clinical evaluation, and anorectal physiologic tests, it is possible to diagnose this problem. Controlled trials are under way to evaluate the efficacy of biofeedback therapy. Meanwhile, it is possible to treat most patients by using neuromuscular conditioning and biofeedback therapy. Further refinements in diagnostic criteria and in rehabilitation therapy programs should facilitate better diagnosis and treatment of patients with dyssynergic defecation.

Reproducibility of colonic transit study in patients with chronic constipation

PURPOSE

Major therapeutic decisions are rendered based on a single colonic transit study. Therefore, the aim of this study was to assess the reproducibility of colonic transit time in patients with chronic constipation.

MATERIALS AND METHODS

Fifty-one patients with chronic idiopathic constipation were randomly selected to undergo two separate colonic transit tests. All clinical conditions, methodology, and patients' instructions were identical on both occasions. The gamma rate (linear correlation analysis) was undertaken between the first and second colonic transit times. Groups were divided according to the diagnoses of colonic inertia (slow-transit constipation), paradoxical puborectalis contraction, and chronic idiopathic constipation (normal-transit constipation).

RESULTS

In 35 of 51 patients (69 percent), the results were identical between the two studies; however, in 16 patients (31 percent), the results were disparate (gamma correlation coefficient = 0.53; P < 0.01). The specific correlation coefficients for patients with colonic inertia, paradoxical puborectalis contraction, and chronic idiopathic constipation were 0.12, 0.21, and 0.60 (P < 0.01), respectively. Moreover, the success rate of colectomy for colonic inertia was significantly higher in patients who underwent a repeat transit study confirming inertia than in patients who underwent colectomy based on a single study.

CONCLUSIONS

Overall, colonic transit time is reproducible in patients with chronic constipation. The correlation coefficient is best for patients with idiopathic constipation and worst for patients with colonic inertia. This new finding suggests that suboptimal surgical outcome may be attributable to inaccurate diagnosis. Because of this poor correlation coefficient, in patients with colonic inertia, consideration should be given to repeating the colonic transit study before colectomy to help secure the diagnosis and improve outcome.

Pharmacotherapy with botulinum toxin: harnessing nature's most potent neurotoxin

Botulinum toxin (BTX), a potent biologic neurotoxin, commonly is associated with lethal outbreaks of food poisoning; however, it also plays a role as a therapeutic agent. Since the 1970s physicians have investigated BTX therapy in patients with neurologic disorders. The number of applications greatly expanded over the years to include certain focal dystonias (blepharospasm, torticollis, laryngeal dystonias, writer's cramp), strabismus, and a wide variety of other indications (gastrointestinal disorders, cosmetic wrinkle correction, spasticity, hyperhidrosis). BTX's safety and efficacy are reviewed.

Botulinum toxin in the treatment of outlet obstruction constipation caused by puborectalis syndrome

PURPOSE

Puborectalis syndrome has been difficult to treat. We investigated the efficacy of botulinum toxin in treating patients with puborectalis syndrome who had previously failed to respond to electromyographic biofeedback sessions and who refused to use anal dilators.

METHODS

Of a group of 50 patients with chronic outlet obstruction constipation, four patients with puborectalis syndrome were included in the study. The patients were studied using anorectal manometry, defecography, and electromyography and then treated with 30 units of Type A botulinum toxin, injected into two sites on either side of the puborectalis muscle, under ultrasonographic guidance.

RESULTS

One patient was lost to follow-up. After treatment in other patients, the frequency of natural bowel movements increased from zero to six per week and laxatives were needed by only one patient. Anorectal manometry demonstrated decreased tone during straining from (mean +/- standard deviation) 96.2 +/- 12 mmHg to 42.5 +/- 13 mmHg at four weeks (P = 0.003) and 63.2 +/- 22 mmHg at eight weeks (P = 0.009). Defecography performed eight weeks after treatment showed improvement in the anorectal angle, which increased from 94 +/- 11 degrees to 114 +/- 13 degrees (P = 0.01), and evacuation of barium paste. Electromyography demonstrated mild paradoxical contraction. However, 16 weeks after treatment one of these three patients suffered symptomatic recurrence. This patient was re-treated with 50 units of toxin; eight months later he required a further 60 units. Seven months after the last injection he reported normal daily bowel movements without the use of laxatives.

CONCLUSIONS

Botulinum toxin injection should be considered as a simple therapeutic approach in patients with puborectalis syndrome. The use of higher dosage and a more precise method of toxin injections under transrectal ultrasonography account for the long-term higher success rate. However, because the effects of the toxin wear off within three months of administration, repeated injections could be necessary to maintain the clinical improvement.

Therapeutic effects of different doses of botulinum toxin in chronic anal fissure

PURPOSE

The aim of this study was to evaluate the clinical and manometric results of three different doses of botulinum toxin and two methods of injection for the treatment of chronic idiopathic anal fissure.

METHODS

Sixty-nine patients with chronic anal fissure were included in a non-randomized, prospective trial of intrasphincteric injection of botulinum toxin. All patients reported postdefecatory anal pain lasting more than two months. Scoring systems were developed for anal pain, bleeding, and defecatory difficulty. Maximum resting and squeeze anal pressures were determined before and one month after treatment. Twenty-three patients undergoing a 5-U injection of diluted botulinum toxin A (BOTOX) on each side of the anal sphincter (total dose, 10 U) constituted the first group. In a second group 27 patients were injected as previously described, with an additional 5-U injection below the fissure (total dose, 15 U). The 19 patients constituting the third group received a 7-U injection on each side of the anus and below the fissure (total dose, 21 U). All patients were followed up for at least six months.

RESULTS

Pain relief one month after treatment was more evident in the second and the third group (48 percent of patients in the first group, 74 percent in the second group, and 100 percent in the third group). A significant reduction of the mean resting pressure was demonstrated only in Groups II and III (P < 0.05), whereas the mean squeeze pressure significantly decreased in the three groups (P < 0.01 in Group I and P < 0.001 in Groups II and III). Fifty-two percent of the patients in the first group, 30 percent in the second group, and 37 percent in the third group were reinjected during the follow-up period, because of persistence of symptomatology or early relapse. The need for surgery was similar in the first and the second group (17 and 19 percent, respectively) and clearly lower in the last group (5 percent). No serious complications or incontinence attributable to this therapeutic modality developed in any patient.

CONCLUSIONS

Intrasphincteric injection of botulinum toxin is a reliable new option in the treatment of uncomplicated chronic anal fissure. The healing rate is related to the dose and probably to the number of puncture sites. No permanent damage to the continence mechanism was detected in these patients.

Botulinum toxin in motor disorders

Advances in the clinical use of botulinum neurotoxins continue. Of interest to the neurologist is the advanced practice in the treatment of focal dystonia and the new developments on other dyskinesias and on autonomic control of smooth muscle motility. New toxin serotypes are now being tested; their availability will improve clinical practice and will possibly lead to combined treatments. Indications in spasticity and in juvenile cerebral palsy are now under scrutiny. The combination of focal chemodenervation with specific rehabilitation procedures enables new development in this field.

Identification of patients likely to benefit from biofeedback for outlet obstruction constipation

BACKGROUND

Biofeedback for outlet obstruction constipation has a varying success rate. The aim of this study was to identify which patients are likely to respond to biofeedback.

METHODS

Thirty patients with severe outlet obstruction constipation were treated by a specialist nurse using three or four sessions of visual and auditory feedback of anal sphincter pressures. All patients were assessed by evacuating proctography, whole-gut transit studies and anorectal physiology before treatment.

RESULTS

Two patients did not complete the course of biofeedback. Nine patients improved. Before treatment these patients had predominantly normal anorectal physiology and were all able to open the anorectal angle at evacuating proctography. Nineteen patients did not improve, of whom only three had no measured abnormality other than inability to empty the rectum. Ten of these patients had abnormal anorectal physiology which may have been due to previous vaginal delivery.

CONCLUSION

Biofeedback for outlet obstruction constipation is more likely to be successful in patients without evidence of severe pelvic floor damage.

Chronic anal fissures treated with botulinum toxin injections: a dose-finding study with Dysport(®)

Botox(®) injection of the anal sphincter muscle cures chronic uncomplicated anal fissures in up to 80% of patients. This study examines the therapeutic efficacy and side effect profile of the British botulinum product Dysport(®) . Fifty patients (29 women) were recruited to participate in this randomized dose-finding study, their mean age being 32.9 years. The low dose group A was treated with a total dose of 20 U injected in two sites each lateral to the fissure, the high dose group B was treated with 40 U. Eighty-two percent of patients were pain-free within a week following the injections. The fissure was healed in 78% of treated patients after 3 months. Three patients relapsed within 6 months. The most common adverse side effect was transient incontinence (n = 4). Clinical outcome was not significantly different between the two treatment groups. The low dose can therefore be regarded sufficient for the treatment of anal fissure. Therapeutic efficacy was equivalent to published data on Botox treatment. Both Dysport(®) and Botox(®) can therefore be used to treat chronic uncomplicated anal fissures. Both Dysport(®) and Botox(®) therapy are well tolerated, can be performed on an out-patient basis and avoid the risk of permanent faecal incontinence which complicates surgical treatment of anal fissures.

Botulinum toxin injections in the internal anal sphincter for the treatment of chronic anal fissure: long-term results after two different dosage regimens

OBJECTIVE

To investigate the effects of two different dosage regimens of botulinum toxin to induce healing in patients with idiopathic anal fissure.

SUMMARY BACKGROUND DATA

Chronic anal fissure is maintained by contraction of the internal anal sphincter. Sphincterotomy, which is successful in 85% to 95% of patients, permanently weakens the sphincter and therefore might be associated with anal deformity and incontinence.

METHODS

Fifty-seven consecutive outpatients were evaluated. Type A botulinum toxin was injected into the internal anal sphincter.

RESULTS

Patients were divided into two treatment groups based on the number of botulinum toxin units injected. Patients in the first group were treated with 15 units and retreated with 20 units. Patients in the second group were treated with 20 units and retreated with 25 units. Two months after treatment, 10 patients in the first group and 23 patients in the second group had a healing scar. Symptomatic improvement was observed in 13 patients in the first group and in 24 patients in the second group. Statistical analysis showed that resting anal pressure varied from baseline values as a function of treatment; in contrast, the treatment had no effect on maximum voluntary pressure. Long-term healing was achieved in 13 patients in the first group and in all patients in the second group who underwent a complete treatment.

CONCLUSIONS

Botulinum toxin is safe and effective in the treatment of anal fissure. It is less expensive and easier to perform than surgical treatment. No adverse effects resulted from injections of the toxin. The higher dosage is effective in producing long-term healing without complications.

Obstructive defecation: a failure of rectoanal coordination

OBJECTIVE

The pathophysiology of obstructive defecation is unclear. We investigated whether impaired rectoanal coordination causes obstructive defecation and if this dysfunction can be corrected by biofeedback therapy.

METHODS

We prospectively studied 25 healthy subjects and 35 consecutive patients with constipation (>1 year) with anorectal manometry and balloon expulsion test. Symptoms were assessed from diary cards. Patients found to have obstructive defecation were offered biofeedback therapy. After treatment, their defecation dynamics and symptoms were reassessed.

RESULTS

Eighteen patients had obstructive defecation and 17 had normal defecation dynamics (nonobstructive). Five normals (20%) exhibited obstructive pattern but only one failed to expel balloon. In the obstructive group, during straining, the intrarectal pressure and defecation index were lower (p < 0.05), and anal residual pressure was higher (p < 0.01) when compared with the nonobstructive group or normals. After biofeedback therapy, the intrarectal pressure and defecation index increased (p < 0.02) and anal residual pressure decreased (p < 0.001); stool frequency, degree of straining, and bowel satisfaction scores improved (p < 0.05); 67% stopped laxatives and 11 patients discontinued stooling with digitation.

CONCLUSION

Patients with obstructive defecation showed impaired rectal contraction, paradoxical anal contraction, or inadequate anal relaxation. These features suggest that rectoanal coordination was impaired. Biofeedback therapy rectified these pathophysiological disturbances and improved constipation.

Involuntary contractions of the striated anal sphincters as a cause of constipation: report of a case

PATIENT HISTORY

We present a case of anismus in a 36-year-old patient. He complained of therapy refractory constipation that had been present for 15 years, with delayed micturition and voiding by stages.

METHODS AND RESULTS

During digital examination of the anal canal, we found spontaneous contractions of the sphincters at rest. The urethral pressure profile showed irregular contractions during micturition. The electromyogram, which was performed with concentric needle electrodes from the external anal sphincter, puborectalis, and external vesical sphincter, revealed synchronous contractions of these muscles. Injections of botulinum toxin into the sphincters showed good effects and no incontinence.

CONCLUSION

Focal dystonia of the striated anal and vesical sphincters is a very rare cause of constipation but should be included in the differential diagnosis.

Histology and function of the internal anal sphincter after injection of botulinum toxin

BACKGROUND

Children with Hirschsprung's disease may have persistent obstructive symptoms due to internal anal sphincter hypertonicity, even after definitive surgery. Anal myectomy is not universally effective and may result in permanent sphincter injury. Botulinum toxin injection has been used to selectively weaken a variety of muscles and could theoretically represent a less invasive option for children with this difficult problem. We evaluated the efficacy and safety of botulinum toxin in an immature porcine model.

MATERIALS AND METHODS

Six-week-old piglets underwent four-quadrant intrasphincteric injection of botulinum toxin or saline. Under ketamine sedation, internal sphincter resting pressure was measured using a water-perfused system before injection and 4 weeks later. Animals were sacrificed 4 weeks after injection. Histological evidence of neuromuscular changes or inflammation in the internal sphincter was documented. All analysis was done blindly.

RESULTS

Internal anal sphincter pressure increased in control animals, likely due to growth over the 4-week period. Conversely, botulinum toxin injection was associated with a significant decrease in internal sphincter pressure. There were no significant differences between the botulinum toxin and control groups with respect to histologic evaluation of neuronal size and number, nerve bundle size and number, inflammation, or muscle atrophy.

CONCLUSIONS

These data suggest that botulinum toxin is effective in decreasing internal anal sphincter pressure without histologically evident adverse effects. A clinical trial using botulinum toxin for persistent obstructive symptoms following surgery for Hirschsprung's disease is therefore justified.

Results of biofeedback in constipated patients: a prospective study

PURPOSE

The aims of this study were to assess the results of biofeedback treatment in constipated patients and to identify variables that might be used to predict the outcome.

METHOD

Twenty-eight patients (5 men; median age, 46 (range, 22-72) years) with any degree of paradoxical activation measured with thin hook needle electromyography in the external sphincter or puborectalis muscle were included. The symptom duration varied between 1 and 30 (median, 9) years. The patients had eight outpatient training sessions with electromyography-based audiovisual feedback. All patients were followed up prospectively with a validated bowel function questionnaire from which a symptom index was created.

RESULTS

At three months, nine patients had no improvement and underwent other treatments. The remaining 19 patients were followed up for a median of 14 (range, 12-34) months. Twelve patients (43 percent) stated they had improved rectal emptying. A good result was associated with increased stool frequency (P < 0.05), improved symptom index (P < 0.01), and reduction of laxative use (P < 0.05). A long symptom duration, a high pretreatment symptom index, and laxative use were related to a poor result (P < 0.01-0.05). The improved group had less perineal descent (P < 0.05), and a prominent puborectalis impression on defecography tended to be more common (P = 0.06).

CONCLUSION

With the use of wide inclusion criteria, biofeedback was successful in 43 percent of patients, with a treatment effect lasting at least one year. The results suggest that biofeedback should be used as the initial treatment of constipated patients with a paradoxical puborectalis contraction.

Outcome and predictors of success of biofeedback for constipation

BACKGROUND

A study was undertaken to determine outcome and to identify predictors of success for biofeedback for constipation.

METHODS

Patients who had at least one biofeedback session were evaluated whether or not they completed a treatment course. Parameters assessed included use of cathartics, number of spontaneous bowel movements per week, presence of rectal pain, number of biofeedback sessions and results of anorectal physiology.

RESULTS

A total of 194 patients (59 male, 135 female) of median age 71 (range 11-96) years, including 30 with concomitant rectal pain, were treated. The median number of spontaneous bowel movements per week before treatment was 0. Some 35 per cent of patients had complete success (three or more spontaneous bowel movements per week with discontinuation of cathartics), 13 per cent had partial success (fewer than three spontaneous bowel movements per week with continued use of cathartics) and 51 per cent had no improvement. Neither patient age, sex nor duration of symptoms significantly affected outcome. Only 18 per cent of patients who had between two and four sessions had complete success, compared with 44 per cent of those who had five or more (P < 0.001). A total of 63 per cent of patients who completed the treatment protocol experienced complete success, compared with 25 per cent of those who self-discharged (P < 0.0001).

CONCLUSIONS

This large study indicates that the success rate of biofeedback for patients with constipation is less than previously reported. However, the success rate improves significantly after five or more sessions and is significantly related to the patient's willingness to complete treatment.

Severe constipation in Parkinson's disease relieved by botulinum toxin

A parkinsonian patient with severe outlet-type constipation was treated with injection of botulinum toxin into the puborectalis muscle. A total of 30 units (Botox) was injected in two sites. Resting anal pressure, maximum voluntary contraction, and pressure on straining were evaluated before treatment and 4, 8, 12, and 16 weeks afterward. Pressure values declined following treatment, the decline of pressure on straining ending by week 12. Proctography performed 8 weeks after treatment showed improvement in the anorectal angle and evacuation of barium paste. The clinical benefit lasted for approximately 12 weeks. The present data show that botulinum toxin is a promising tool for treating outlet-type constipation in Parkinson's disease.

One hundred cases of anal fissure treated with botulin toxin: early and long-term results

PURPOSE

Sphincterotomy still is considered the therapy of choice to eliminate sphincter spasm in the treatment of uncomplicated chronic anal fissure. The surgery is weighted with the possible surgical risk and the risk of subsequent fecal incontinence. This study reports the effect of botulin toxin injections within the first six months.

PATIENTS AND METHODS

One hundred patients were treated (43 females; average age, 34.7 years). The injection of botulin toxin (2.5-5 units of Botox each) was done bilaterally to the fissure, thereby causing paresis of the sphincters for approximately three months. Patients were re-examined after one week and three and six months.

RESULTS

Within the first week, 78 percent of patients were free of pain. In 82 percent of patients, complete healing of the fissure occurred within the first three months. Eight patients experienced relapses within the first six months of therapy, three of whom needed surgical intervention. The healing rate after six months was 79 percent. No healing occurred in 21 patients, and they had to undergo surgery. Transitory fecal incontinence resulted in seven cases.

CONCLUSIONS

Injection of botulin toxin enables us to treat chronic, uncomplicated anal fissures with increased sphincter tone. It is well tolerated, can be administered on an outpatient basis, does not cause any lesion of the continence organ, and subsequently, does not lead to any permanent latent or apparent fecal incontinence.

Biofeedback retraining in patients with functional constipation and paradoxical puborectalis contraction: comparison of anal manometry and sphincter electromyography for feedback

PURPOSE

This study was undertaken to assess the effect of biofeedback therapy in patients with constipation and paradoxical puborectalis contraction and to compare two different feedback modes.

METHODS

Twenty-six patients were randomly allocated to either of two feedback modes: anal pressure using a manometry probe or anal sphincter electromyography (EMG) using surface electrodes.

RESULTS

Six patients were unable to complete their training; ten patients were retrained using anal manometry and ten patients using EMG. The paradoxical puborectalis contraction disappeared after retraining with manometry feedback in eight of ten patients and with EMG feedback in ten of ten patients. A significant improvement in both bowel function and abdominal symptoms was found after training and a continued improvement at follow-up six months later. Six patients in the manometry group and nine in the EMG group experienced an overall improvement in symptoms. The two feedback methods did not differ in terms of efficacy.

CONCLUSIONS

Our results suggest that biofeedback, using either manometry or EMG, is effective in improving symptoms and anorectal function caused by paradoxical puborectalis contraction.

Treatment of puborectalis syndrome with progressive anal dilation

PURPOSE

The aim of this study is to assess the ability of progressive anal dilations to improve frequency of spontaneous bowel movements in patients with puborectalis syndrome (PRS).

METHOD

Thirteen patients (9 females and 4 males; mean age, 37 years) with severe, chronic constipation caused by PRS were treated with daily, progressive anal dilation for a three-month period. Three dilators of 20, 23, and 27 mm in diameter were used. Dilators were inserted every day for 30 minutes (10 minutes each dilator). Patients were evaluated with anorectal manometry and defecography halfway through treatment, at the end of treatment, and six months after the end of treatment. At six months, patients also underwent physical examination.

RESULTS

There was a significant improvement of weekly mean spontaneous bowel movements from zero to six (P < 0.0001), and the need for laxatives decreased from 12 patients with a weekly mean of 4.6 to 2 patients once per week (P < 0.001). Enemas used before treatment by eight patients who had a weekly mean of 2.3 were, after treatment, needed only by three patients once per week (P < 0.01). During straining, tone measured with anorectal manometry decreased from 93 to 62 mmHg after six months of the end of therapy (F = 6.97; P < 0.01), and anorectal angle measured with defecography during the strain increased from 95 degrees to 110 degrees (P = not significant).

CONCLUSIONS

Daily progressive anal dilation should be considered as the first and most simple therapeutic approach in patients with PRS.

Initial North American experience with botulinum toxin type A for treatment of anismus

PURPOSE

Botulinum toxin type A (BTX-A), produced by Clostridium botulinum, is a potent neurotoxin. The purpose of this study was to evaluate the efficacy of BTX-A for treatment of anismus.

MATERIALS AND METHODS

All patients treated with BTX-A for anismus were evaluated. Eligibility criteria included a history of chronic assisted evacuation (laxatives, enemas, or suppositories), demonstration of anismus by cinedefecogram and electromyography, and failure of a minimum of three sessions of supervised biofeedback therapy (BF). Contingent on body mass, 6 to 15 units of BTX-A was injected bilaterally under electromyography guidance into the external sphincter or the puborectalis muscle. Treatment was repeated as necessary for a maximum of three sessions during a three-month period. Success was considered as discontinuation of evacuatory assistance and was evaluated between one and three months and again at up to one year.

RESULTS

Between July 1994 and May 1995, four patients ranging from 29 to 82 years in age (2 females, 2 males) had anismus that failed to respond to between 3 and 15 biofeedback sessions. All patients improved between one and three months after BTX-A injection, and two had sustained improvement for a range of three months to one year. There was no morbidity or mortality associated with BTX-A injection.

CONCLUSIONS

BTX-A is extremely successful for temporary treatment of anismus that is refractory to BF management. However, because the mechanism of action is short, longer term results are only 50 percent successful. Hopefully, modifications in the strain of BTX-A and dose administered will allow longer periods of success or a repeat trial of BF. Nonetheless, this preliminary report is very encouraging in offering a method of managing this recalcitrant condition.

[Mechanism of action, clinical indication and results of treatment of botulinum toxin]

Botulinum toxin, the most potent of the neurotoxins, produces paralysis by blocking presynaptic release of the neurotransmitter (acetylcholine) at the neuromuscular junction, with reversible chemical denervation of the muscle fibre, thereby inducing partial paralysis and atrophy. Because chemical denervation is reversible, botulinum toxin has temporary effects, the muscle being progressively reinnervated by nerve sproutings. Type A botulinum toxin (Bix-A) is available under two dosage forms: Botox and Dysport. Although the initial clinical indication was strabismus, subsequent studies have demonstrated the efficacy of Btx-A, mainly in dystonia, hemifacial spasm and spasticity. However, botulinum toxin has been successfully used in various other clinical indications. In regard to spasticity associated with cerebral palsy, Btx-A is a promising treatment requiring a multidisciplinary approach. Btx-A injections lead to effective reduction of muscle hyperactivity with minor side-effects. They are painless, even though electromyographic guidance may be required for the injection of deep muscles. However, the production of antibodies to Btx-A may compromise the effect of long-term treatment.

Patterns of anismus and the relation to biofeedback therapy

PURPOSE

A study was undertaken to assess physiologic characteristics and clinical significance of anismus. Specifically, we sought to assess patterns of anismus and the relation of these findings to the success of therapy.

METHODS

Sixty-eight patients were found to have anismus based on history and diagnostic criteria including anismus by defecography and at least one of three additional tests: anorectal manometry, electromyography, or colonic transit time study. Interpretation of defecography was based on the consensus of at least three of four observers. Anal canal hypertonia (n = 32) was defined when mean and maximum resting pressures were at least 1 standard deviation higher than those in 63 controls. There were two distinct defecographic patterns of anismus: Type A (n = 26), a flattened anorectal angle without definitive puborectalis indentation but a closed anal canal; Type B (n = 42), a clear puborectalis indentation, narrow anorectal angle, and closed anal canal. Outcomes of 57 patients who had electromyographybased biofeedback therapy were reported as either improved or unimproved at a mean follow-up of 23.7 (range, 6-62) months. These two types of anismus were compared with biofeedback outcome to assess clinical relevance.

RESULTS

Patients with Type A anismus showed greater perineal descent at rest (mean, 5.1 vs. 3.5 cm; P < 0.01), greater dynamic descent between rest and evacuation (mean, 2.7 vs. 1.4 cm; P < 0.01), greater difference of anorectal angle between rest and evacuation (mean, 14.6 vs. -3.1 degrees; P < 0.001), higher mean resting pressure (mean, 77.1 vs. 62.8 mmHg; P < 0.05), lower mean squeeze pressure (58.8 vs. 80.7 mmHg; P < 0.05), and a higher incidence of anal canal hypertonia (69.2 vs. 33.3 percent; P < 0.01) than did patients with Type B anismus. Only 25 percent of patients who had Type A anismus with anal canal hypertonia were improved by biofeedback therapy. Conversely, 86 percent of patients with Type B anismus without anal canal hypertonia were successfully treated with biofeedback (P < 0.001; Fisher's exact test).

CONCLUSIONS

These two distinct physiologic patterns of anismus correlate with the success of biofeedback treatment. Therefore, knowledge of these patterns may help direct therapy.

Clinical and physiologic effects of biofeedback in outlet obstruction constipation

PURPOSE

We report the results of biofeedback (BF) on patients with outlet obstruction defecation (OOC), including those with and without measurable paradoxical puborectalis contractions (PP). Clinical and anorectal physiologic parameters (ARP) were assessed one week before and after a standardized course of BF.

METHODS

Sixty-two consecutive patients (24 men, 38 women; mean age, 48 (standard error of the mean, 2.3) years) were recruited. All had persistent constipation despite six weeks of dietary fiber supplements. Colonic inertia was excluded by transit marker studies. Defecating proctography excluded anatomic abnormalities causing outlet obstruction. Patients underwent four outpatient sessions of biofeedback, each session lasting one hour.

RESULTS

After BF, 56 patients (90.3 percent) were subjectively improved. Frequency of spontaneous bowel movements were significantly increased (P = 0.003). Frequency of laxative-induced (P = 0.004) and enema-induced (P = 0.005) stools were reduced. Anal resting (P = 0.04) and squeeze (P = 0.002) pressures were increased. Number of patients with PP was reduced from 40 to 31 (P = 0.004). Presence of PP did not affect response to BF. There were no differences in ARP between the 56 patients who improved and the 6 who did not. There were no side effects or clinical regressions after a mean follow-up of 14.9 (standard error of the means, 0.9) months.

CONCLUSIONS

BF effectively treated OOC in 90.3 percent, regardless of PP. Anal pressures were increased, and PP was decreased.