Intrasphincteric botulinum toxin for the treatment of achalasia

[Pseudoachalasia due to amyloidosis treated by botulinum toxin]

INTRODUCTION

Pseudoachalasia mimics primary achalasia and can provoke serious complications in the elderly.

CASE RECORD

A 84 years-old woman had dysphagia with recurrent pneumonia. Pseudoachalasia related to a multifocal primitive amyloidosis was diagnosed. Treatment with botulinum toxin injection during a gastric fibroscopy resulted in clinical improvement, still notable 15 months later.

DISCUSSION

Botulinum toxin injection may be a useful tool in treatment of pseudoachalasia due to amyloidosis.

Botulinum toxin type A for poststroke cricopharyngeal muscle dysfunction

OBJECTIVE

To evaluate the therapeutic effectiveness of botulinum toxin type A (BTX-A) in poststroke patients with cricopharyngeal muscle dysfunction.

DESIGN

Before-after trial.

SETTING

University hospital.

PARTICIPANTS

Eight poststroke patients.

INTERVENTION

BTX-A injection into the cricopharyngeal muscle under endoscope guidance for poststroke cricopharyngeal muscle dysfunction.

MAIN OUTCOME MEASURES

Clinical symptom score, disability rating scale for swallowing impairment, videofluoroscopic swallowing study, and upper esophageal sphincter (UES) manometry.

RESULTS

Clinical symptom score, disability rating scale for swallowing impairment, residue in piriform sinus, and UES pressure were all significantly improved at 2 weeks after BTX-A injection compared with evaluations before injection (P<.05). The effects on the clinical symptom score and disability rating scale for swallowing impairment continued to be significantly improved to 12 weeks after injection (P<.05). However, the residue in piriform sinus and the UES pressure at 12 weeks postinjection were reduced compared with before-injection evaluations; these results were not significant. The pharyngeal transit time was not changed after injection. There were no side effects observed in the patients studied.

CONCLUSIONS

The results of the present study suggest that BTX-A injection may be an effective and safe treatment in patients with poststroke cricopharyngeal muscle dysfunction.

Endoscopic pneumatic dilation versus botulinum toxin injection in the management of primary achalasia

BACKGROUND

Achalasia is an oesophageal motility disorder, of unknown cause, which results in increased lower oesophageal sphincter (LOS) tone and symptoms of difficulty swallowing. Treatments are aimed at reducing the LOS tone. Current endoscopic therapeutic options include pneumatic dilation (PD) or botulinum toxin injection (BTX).

OBJECTIVES

The objective of this review was to compare the efficacy and safety of two endoscopic treatments, pneumatic dilatation and intrasphincteric botulinum toxin injection, in the treatment of oesophageal achalasia.

SEARCH STRATEGY

We searched the Cochrane Upper Gastrointestinal and Pancreatic Diseases Group trials register, the Cochrane Central Register of Controlled Trials, MEDLINE (1966 to Oct 2005), EMBASE (1980 to Oct 2005), BIOSIS (1969 to Oct 2005) and Web of Science (1955 to October 2005). We also searched abstracts from significant Gastroenterology meetings (DDW, UEGW) and reference lists of articles.

SELECTION CRITERIA

Randomised controlled trials comparing PD to BTX injection in patients with primary achalasia.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed quality assessment and data extraction.

MAIN RESULTS

Six studies involving 178 participants were included. Two studies were excluded from the meta-analysis of remission rates on the basis of clinical heterogeneity of the initial endoscopic protocols. There was no significant difference in remission between PD or BTX treatment within four weeks of the initial intervention, with a relative risk of remission of 1.15 (95% CI 0.95 to 1.38, P = 0.39) for PD compared to BTX. There was also no significant difference in the mean oesophageal pressures between the treatment groups; weighted mean difference for PD of -0.77 (95% CI -2.44 to 0.91, P = 0.37). Data on remission rates following the initial endoscopic treatment was available for two studies at six months and three studies at 12 months. At six months 22 of 29 PD participants were in remission compared to 7 of 27 in the BTX group, giving a relative risk of 2.90 (95% CI 1.48 to 5.67, P = 0.002); whilst at 12 months 33 of 47 PD participants were in remission compared to 11 of 43 BTX participants, relative risk of 2.67 (95% CI 1.58 to 4.52, P = 0.0002). No serious adverse outcomes occurred in participants receiving BTX, whilst PD was complicated by perforation in three cases.

AUTHORS' CONCLUSIONS

The results of this meta-analysis would suggest that PD is the more effective endoscopic treatment in the long term (greater than six months) for patients with achalasia.

Non-surgical treatment of esophageal achalasia

Esophageal achalasia is an infrequent motility disorder characterized by a progressive stasis and dilation of the oesophagus; with subsequent risk of aspiration, weight loss, and malnutrition. Although the treatment of achalasia has been traditionally based on a surgical approach, especially with the introduction of laparoscopic techniques, there is still some space for a medical approach. The present article reviews the non-surgical therapeutic options for achalasia.

Review article: the management of achalasia - a comparison of different treatment modalities

BACKGROUND

Achalasia is an uncommon primary oesophageal motor disorder with an unknown aetiology. Therapeutic options for achalasia are aimed at decreasing the lower oesophageal sphincter pressure, improving the oesophageal empting, and most importantly, relieving the symptoms of achalasia. Modalities for treatment include pharmacologic, endoscopic, pneumatic dilatation and surgical. The decision of which modality to use involves the consideration of multiple clinical and economic factors.

AIM

To review the management strategies currently available for achalasia.

METHODS

A Medline search identified the original articles and reviews the published in the English language literature between 1966 and 2006.

RESULTS

The results reveal that pharmacotherapy, injection of botulinum toxin, pneumatic dilatation and minimally invasive surgical oesophagomyotomy are variably effective at controlling the symptoms of achalasia but that each modality has specific strengths and weaknesses which make them each suitable in certain populations. Overall, pharmacologic therapy results in the shortest lived, least durable response followed by botulinum toxin injection, pneumatic dilatation and surgery, respectively.

CONCLUSION

The optimal treatment for achalasia remains an area of controversy given our lack of complete understanding about the pathophysiology of the disease as well as the high numbers of clinical relapse after treatment. Further research focusing on optimal dosing of botulinum toxin injection and optimal timing of repeated graduated pneumatic dilatations could add to our knowledge regarding long-term therapy.

Botulinum toxin: Clinical use

Since its development for the use of blepharospasm and strabismus more than 2.5 decades ago, botulinum neurotoxin (BoNT) has become a versatile drug in various fields of medicine. It is the standard of care in different disorders such as cervical dystonia, hemifacial spasm, focal spasticity, hyperhidrosis, ophthalmological and otolaryngeal disorders. It has also found widespread use in cosmetic applications. Many other indications are currently under investigation, including gastroenterologic and urologic indications, analgesic management and migraine. This paper is an extensive review of the spectrum of BoNT clinical applications.

Botulinum toxin for gastrointestinal disorders: therapy and mechanisms

Botulinum toxin has gained widespread acceptance as a treatment option for various spastic gastrointestinal disorders such as achalasia, gastroparesis, sphincter of Oddi dysfunction, chronic anal fissures, and pelvic floor dyssnergia, despite the lack of strong evidence supporting its use in many of these diseases. This review summarizes the trials investigating the use of BoNT since it was first utilized as a treatment in achalasia. BoNT has proven to be safe, but long-term efficacy in many disorders has not been observed, primarily due to is relatively short duration of action. BoNT may be most useful in confirming a diagnosis which can lead to a more definitive treatment modality. Furthermore, its safety profile allows it to be a useful alternative in patients who are at high risk for invasive procedures.

Treatment with botulinum toxin of octo-nonagerians with oesophageal achalasia: a two-year follow-up study

BACKGROUND

Treatment of oesophageal achalasia with intrasphincteric injections of botulinum toxin has proved to be a successful alternative treatment modality. However, little is known about its long-term effects in very old patients.

AIM

To evaluate the effects of such treatment in octo-nonagerians during a 2-year follow-up period.

PATIENTS AND METHODS

Thirty-three patients with idiopathic oesophageal achalasia (range 81-94 years) entered the study. After basal evaluation and screening procedures, 100 U of botulinum toxin was injected at the lower oesophageal sphincter, and the procedure was repeated 1 month later. Data were collected at baseline and were compared after 1 and 2 years following the procedure.

RESULTS

Seventy-eight per cent of patients were considered responders at 1 year and 54% were considered responders at 2 years. The weight gain at the end of the follow-up period was 2 (0-3) kg. No significant relationship was found between baseline lower oesophageal sphincter pressure and symptoms score after 1 and 2 years of follow-up; moreover, no major complications of botulinum toxin therapy were reported.

CONCLUSION

Treatment of very old achalasic patients with botulinum toxin is safe, effective and yields good quality of life in a substantial proportion of these subjects.

Gastroparesis: clinical update

Gastroparesis refers to chronically abnormal gastric motility characterized by symptoms suggestive of mechanical obstruction and delayed gastric emptying in the absence of mechanical obstruction. It may be idiopathic or attributable to neuropathic or myopathic abnormalities, such as diabetes mellitus, postvagotomy, postviral infection, and scleroderma. Dietary and behavioral modification, prokinetic drugs, and surgical interventions have been used in managing patients with gastroparesis. Although mild gastroparesis is usually well managed with these treatment options, severe gastroparesis may be very difficult to control and may require referral to a specialist center if symptoms are intractable despite pharmacological therapy and dietetic support. New advances in drug therapy, botulinum toxin injection, and gastric electrical stimulation techniques have been introduced and might provide new hope to patients with refractory gastroparesis. This article critically reviews the advances in the field from the perspective of the clinician.

Unlabeled uses of botulinum toxins: a review, part 1

PURPOSE

Efficacy and safety data regarding the unlabeled uses of botulinum toxins are reviewed, and the pharmacology, adverse effects, and characteristics of commercially available botulinum toxins are discussed.

SUMMARY

More than 300 articles have been published on the use of botulinum toxins, particularly botulinum toxin type A, to treat conditions characterized by excessive smooth or skeletal muscle spasticity. Botulinum toxins are synthesized by Clostridium botulinum and cause temporary local paralysis of the injected muscle by inhibiting acetylcholine release at the neuromuscular junction. While botulinum toxins have Food and Drug Administration-approved labeling to treat a limited number of spasticity disorders, including cervical dystonia and blepharospasm, the toxins have more than 50 reported therapeutic uses. Among these uses, the most rigorously studied indications include achalasia, essential tremors, palmar hyperhidrosis, chronic anal fissures, headache prophylaxis, and limb spasticity. The main adverse effects of the toxins are pain and erythema at the injection site, although unintended paralysis of muscles adjacent to the site of toxin injection may also occur.

CONCLUSION

Clinical studies support the use of botulinum toxins for certain conditions, although more studies are needed to establish the role of the drug relative to conventional therapies and to determine patient predictors of response. Although botulinum toxins are generally well tolerated, a patient-specific risk-benefit assessment should precede any decision to use them for unlabeled indications.

Relationship between subjective and objective outcome measures after Heller myotomy and Dor fundoplication for achalasia

BACKGROUND

The purpose of this study is to assess how subjective evaluation (heartburn, dysphagia, quality of life, and satisfaction) correlates with objective data after Heller myotomy and Dor fundoplication for achalasia.

METHODS

A total of 53 consecutive patients with achalasia undergoing laparoscopic Heller myotomy and Dor fundoplication were studied prospectively. Subjective evaluation was done preop and postop using the Gastroesophageal Reflux Disease Health-Related Quality of Life instrument (GERD-HRQL; 0 = best, 45 = worse), 4-point dysphagia and heartburn scales (0 = best, 3 = worst), patient satisfaction scale (0 = very satisfied, 5 = incapacitated), and the SF-12 general health-related quality-of-life score. At 3 months postop, patients were asked to undergo objective evaluation with 24-h pH testing, manometry, and endoscopy. Data are expressed as median (interquartile range) and analyzed by Wilcoxon signed rank test or Mann-Whitney U test.

RESULTS

Forty-nine patients were more than 3 months postsurgery. Comparing preop to postop, improvements were found in dysphagia [3 (2-3) to 0 (0-1)], heartburn [1 (0-2) to 0 (0-1)], GERD-HRQL [13.5 (6.3-22.5) to 2 (0-5)], satisfaction [3 (3-4) to 1 (0-1)], and SF-12 mental component summary [46 (37-56) to 58 (50-59)] and physical component summary [46 (36-53) to 55 (48-56)] scores (p < 0.0001 for all). Thirty-eight patients (78%) agreed to undergo objective testing, and complete data were available for 32 (65%). Four of 32 patients (12.5%) had evidence of reflux based on 24-h pH testing. Of nine patients with GERD-HRQL >5, only two had positive pH test (22%). Of 23 patients with GERD-HRQL <5, two had positive pH test (7%). Of four tested patients with moderate to severe heartburn, two had an abnormal pH test. There was no significant relationship between GERD-HRQL score and pH test results. Lower esophageal sphincter pressure (LESP) decreased from 24 (16-35) to 13 mmHg (11-17) (p < 0.001). There was no relationship between dysphagia score and postop absolute LESP or a decrease in LESP after operation.

CONCLUSIONS

Laparoscopic Heller myotomy and Dor fundoplication is an effective treatment for achalasia. Subjective evaluation can document patient satisfaction and health-related quality of life but does not accurately reflect postop reflux. Twenty-four-hour pH study is required to accurately assess reflux disease.

Long-term outcomes of laparoscopic heller cardiomyotomy without an anti-reflux procedure

Certain technical features of laparoscopic Heller cardiomyotomy (LHM) remain controversial, including the extent of the myotomy and the indication for an antireflux procedure. We completed a retrospective chart review of all patients who underwent LHM for achalasia at 1 tertiary care institution to review our institutional experience with LHM without an antireflux procedure. Forty patients underwent a LHM performed by 2 surgeons, 65% of whom had previous medical management (Botox: 12 patients, LES dilatation: 14). The operating time was significantly increased in patients with Botox injections (98.3 vs. 71.1 minutes, P = 0.005). There were 3 intraoperative complications (mucosal injury in 3 patients, 2 had Botox injections). Postoperative evaluation demonstrated a mean dysphagia score of 0.2, a mean heartburn score of 3.2, and a mean LES pressure of 6.32 mm Hg. Thirty-two patients are maintained on acid-suppressing medications with good control of reflux symptoms. LHM without an antireflux procedure achieves excellent clinical outcomes in most patients with achalasia regardless of previous medical management. Previous medical management may present a greater technical challenge and may place patients at increased risk of mucosal injury.

Randomized prospective controlled trial of lateral internal sphincterotomy versus injection of botulinum toxin for the treatment of idiopathic fissure in ano

BACKGROUND

Chronic anal fissure is a significant cause of morbidity. Internal sphincterotomy has long been the operative treatment of choice. Concerns remain, however, on its effects on continence. Botulinum toxin has been used as an agent for chemical sphincterotomy, causing temporary alleviation of sphincter spasm and allowing the fissure to heal. The aim of the present study was to compare the results of sphincterotomy to botulinum toxin.

METHODS

The study was designed as a randomized controlled trial. All adult patients over the age of 18 with chronic idiopathic fissure in ano who had failed conservative treatment were included in the trial. Patients were randomized to receive either Botox or sphincterotomy. Pain, healing of fissure and continence scores were the outcomes assessed.

RESULTS

A total of 38 patients were studied. Seventeen patients were randomized to receive Botox and 21, sphincterotomy. Patients in the Botox group were found to have significantly higher 2-week pain scores and reoperation rates, and poor healing. Continence scores were not significantly different in the two groups.

CONCLUSION

Sphincterotomy gives better results than Botox in the treatment of fissure. Botox, however, is safe with no complications and no detriment to continence and could be used in certain situations.

Laparoscopic Heller myotomy for achalasia

BACKGROUND

Achalasia is an uncommon illness affecting 1 per 100,000 patients yearly. There is evidence to suggest viral, autoimmune, and hereditary etiologies. There are many treatment options available including medications, botulinum toxin injection, pneumatic dilation, and surgical myotomy.

METHODS

We present a retrospective review of patients undergoing laparoscopic-modified Heller myotomy at a large referral and surgical training center.

RESULTS

There were 36 patients identified. Thirty patients had undergone prior treatment with botulinum toxin injection, pneumatic dilation, previous Heller myotomy, or esophageal stenting. Immediate complications included mucosal perforation (2), spleen injury (1), and trocar-site infection (1). There were no postoperative esophageal leaks. Three patients suffered reflux requiring the daily use of a proton pump inhibitor 9 months after surgery. Three patients suffered recurrent dysphagia.

CONCLUSIONS

Presently, there are little data to suggest an ideal management strategy in patients with achalasia. Our patient population consists predominantly of failures of other treatment methods submitted for laparoscopic myotomy. Our data suggest that laparoscopic Heller myotomy can be safely undertaken in this population, without a higher than expected rate of recurrent symptoms or reflux.

The lower oesophageal sphincter

The lower oesophageal sphincter (LOS) is a specialized segment of the circular muscle layer of the distal oesophagus, accounting for approximately 90% of the basal pressure at the oesophago-gastric junction. Together with the crural diaphragm, it functions as an antireflux barrier protecting the oesophagus from the caustic gastric content. During swallowing or belching, the LOS muscle must relax briefly in order to allow passage of food or intragastric air. These swallow-induced and prolonged transient lower oesophageal sphincter relaxations (TLOSRs) respectively result from activation of the inhibitory motor innervation of the sphincter. Both in man and animals, the main neurotransmitter released by the inhibitory neurones is nitric oxide. The two typical examples of dysfunction of the LOS are achalasia and gastro-oesophageal reflux disease (GORD). Achalasia is characterized by reduction or even absence of the inhibitory innervation to the LOS, leading to impaired LOS relaxation with dysphagia and stasis of food in the oesophagus. On the contrary, GORD results from failure of the antireflux barrier, with increased exposure of the oesophagus to gastric acid. This leads to symptoms such as heartburn and regurgitation, and in more severe cases to oesophagitis, Barrett's oesophagus and even carcinoma. To date, TLOSRs are recognized as the main underlying mechanism, and may represent an important target for treatment. More insight in the pathogenesis of both diseases will undoubtedly lead to new treatments in the near future.

Endoscopic pyloric injection of botulinum toxin A for the treatment of refractory gastroparesis

BACKGROUND

Botulinum toxin A injected into the pyloric sphincter has been reported in small case series to treat gastroparesis. This study reviews the use of this treatment in a large number of patients with gastroparesis.

METHODS

Patients who underwent pyloric botulinum injection for treatment of gastroparesis were identified. Response was defined as improvement or resolution of the patient's major symptom and/or two minor symptoms for 4 weeks.

RESULTS

Of 115 patients treated, 63 patients met the study criteria. There were 53 women, 10 men, mean age 42 years. Most patients (56%) had idiopathic gastroparesis. Twenty-seven of 63 (43%) patients experienced a symptomatic response to treatment. By stepwise logistic regression, male gender was associated with response to treatment (OR 3.27: 95% CI[1.31, 8.13], p = 0.01). Vomiting as a major symptom was associated with a lack of response (OR 0.16: 95% CI[0.04, 0.67], p = 0.01). Despite the association of male gender with response, the mean duration of response for those patients responding, with a minimum of 3 months' follow-up was 4.9 months (+/-2.7 months) for women and 3.5 months (+/-0.71 months) for men (p = 0.59). The corresponding medians and interquartile ranges (IQR) were 5 (IQR 3-6) for females and 3.5 (IQR 3-4) for males.

CONCLUSIONS

Of the patients, 43% had a response to botulinum toxin treatment that lasted a mean of approximately 5 months. Male gender was associated with a response to this therapy; however, durability of response was unrelated to gender. Vomiting as a major symptom predicted no response.

Esophagotomy during laparoscopic Heller myotomy cannot be predicted by preoperative therapies and does not influence long-term outcome

The conventional wisdom is that inadvertent esophagotomy complicates laparoscopic Heller myotomy. This study was undertaken to determine if esophagotomy at myotomy can be predicted by preoperative therapy, and if esophagotomy and/or its repair jeopardizes outcomes. Of 222 laparoscopic Heller myotomies undertaken since 1992, inadvertent esophagotomy occurred in 16 patients (7%); 60 patients who underwent myotomy without esophagotomy were utilized for comparison. Dysphagia and reflux before/after myotomy were scored by patients on a Likert scale (0-5). The median (mean +/- SD) follow-up after myotomy with esophagotomy was 38.8 months (31.6 +/- 21.9 months) versus 46.3 months (51.0 +/- 21.2 months) after myotomy alone. All esophagotomies were immediately recognized and repaired. Patients who experienced esophagotomy were similar to those who did not in application of Botox (56% vs. 77%) or dilation (44% vs. 65%), years of dysphagia (7.3 +/- 5.4 vs. 7.4 +/- 6.0), and mean preoperative dysphagia score (4.9 +/- 0.4 vs. 4.8 +/- 0.4). Esophagotomy led to longer hospitalizations (5.2 days +/- 2.5 days vs. 1.5 days +/- 0.7 days, P < 0.05) but not different postoperative dysphagia scores (1.5 +/- 1.7 vs. 2.1 +/- 1.4), reflux scores (1.4 +/- 1.7 vs. 2.3 +/- 1.3), or good or excellent outcomes (86% vs 84%). Esophagotomy during laparoscopic Heller myotomy is infrequent and cannot be predicted by preoperative therapy or duration or severity of dysphagia. Furthermore, complications after esophagotomy are infrequent and outcomes are indistinguishable from those of patients undergoing uneventful myotomy.

Treatment of Achalasia

Achalasia is a primary motility disorder of the esophagus that causes dysphagia. Normal esophageal motility and lower esophageal sphincter (LES) function can not be restored; thus treatment is directed at decreasing the pressure or disrupting the muscle fibers of the LES to allow passage of ingested material. Effective therapy for achalasia can be broadly characterized as surgery based or endoscopy based. Medications (calcium channel blockers and nitrate derivatives) do not provide adequate relief of dysphagia and have substantial side effects, and thus are rarely used as long-term therapy. Botulinum toxin injection, a recently introduced endoscopic therapy, enjoyed much enthusiasm initially but was shown to have only transient effect and is now recommended only for poor operative candidates. The mainstay of therapy remains endoscopic dilation or laparoscopic esophagomyotomy (LEM) combined with an antireflux procedure. We have found that patients who can tolerate a laparoscopic abdominal surgery are best served with an LEM and Toupet (270 degrees ) posterior fundoplication. This provides good or excellent relief of dysphagia in 90% to 95% of patients with very little morbidity.

From frown lines to fissures: Therapeutic uses for botulinum toxin

INTRODUCTION

Since the pharmacological mode of action of botulinum toxin (BTX) has been elucidated, its therapeutic potential has been increasingly recognised. The aims of this review were to summarize our current understanding of the pharmacological action of this agent and to review its therapeutic uses.

METHODS

An electronic literature search with Medline (January 1965 to December 2004) was carried out to identify articles related to the pharmacological mode of action and clinical uses for botulinum toxin using the keyword "botulinum toxin".

RESULTS AND CONCLUSION

Botulinum toxin A is emerging as a valuable clinical tool, both for diagnostic and therapeutic purposes in a wide variety of disorders, and is already the treatment of choice for selected conditions. Better understanding of its modes of action may identify alternative targets for pharmacological intervention, and may allow development of longer acting drugs with lower immunogenicity. Therapeutic uses of BTX-A must be assessed systematically in prospective studies, and the clinical role of other subtypes requires evaluation.

Endoscopic ultrasound-guided fine-needle injection

With the development of linear array echoendoscopes and the ability to perform endoscopic ultrasound (EUS)-guided fine-needle aspiration, the delivery of therapeutic agents with fine-needle injection (FNI) emerged. EUS-guided FNI is an attractive delivery system because of its minimal invasiveness and low complication rate. This approach is effective in performing celiac plexus neurolysis for pain relief in patients with pancreatic cancer. The most exciting area of interest involves the delivery of antitumor agents in patients with locally advanced cancer, such as cancer of the pancreas or esophagus. The involvement of EUS-guided FNI in tumor therapy adds a host of potential new applications that continue to swing the pendulum of EUS from a diagnostic to a therapeutic modality.

Botulinum toxin treatment of oesophageal achalasia in the old old and oldest old: a 1-year follow-up study

BACKGROUND

Intrasphincteric injection of botulinum toxin (BTX) has become one of the most frequent therapeutic approaches for the treatment of oesophageal achalasia. This treatment seems particularly effective in elderly patients who are not candidates for more invasive procedures.

AIMS

There are few or no data on BTX treatment of achalasia in the old old and oldest old. Therefore, we evaluated BTX treatment in a group of patients with achalasia in the extreme age range who were too ill or frail to undergo surgery or pneumatic dilatation.

PATIENTS AND METHODS

Twelve elderly achalasic patients (age range 81-94 years, average age 86 years) with American Society of Anesthesiologists (ASA) class III-IV status were recruited for the study. After baseline clinical and instrumental evaluations, BTX 100U was injected at time 0 and 1 month later. Clinical follow-up was carried out after 3, 6 and 12 months.

RESULTS

A significant improvement in symptom score was documented at each follow-up step. On the basis of improvements in scores, approximately 70% of patients were considered responders at the end of follow-up.

CONCLUSIONS

BTX treatment is an effective treatment in a substantial proportion of achalasic patients >80 years of age, in whom benefits are still detectable after 12 months. BTX is a therapeutic option in patients unsuitable for surgery or pneumatic dilatation.

American Gastroenterological Association technical review on the diagnosis and treatment of gastroparesis

This literature review and the recommendations herein were prepared for the American Gastroenterological Association Clinical Practice Committee. The paper was approved by the Committee on May 16, 2004, and by the AGA Governing Board on September 23, 2004.

The treatment of diabetic gastroparesis with botulinum toxin injection of the pylorus

OBJECTIVE

Gastroparesis is a disorder of delayed gastric emptying that is often chronic in nature. Up to 50% of type 1 diabetic subjects have symptoms of gastroparesis, which include nausea, vomiting, and early satiety. Elevated pyloric pressures may be responsible for delayed gastric emptying in diabetic subjects. Botulinum toxin inhibits the release of acetylcholine and produces transient paralysis when injected into smooth muscle. The aim of this study was to determine whether injection of the pylorus with botulinum toxin in patients with diabetic gastroparesis improves symptoms of gastroparesis, alters gastric emptying scan time, and/or changes weight and insulin use.

RESEARCH DESIGN AND METHODS

This was an open-label trial with age- and sex-matched control subjects from a tertiary care referral center for patients with gastroparesis. Eight type 1 diabetic subjects (six women and two men; mean age 41 years; mean years with diabetes 25.3) who had failed standard therapy were enrolled. Intervention consisted of injection of the pylorus with 200 units of botulinum toxin during upper endoscopy. Symptoms, antropyloric manometry, gastric emptying scan times, weight, and insulin use were all recorded before intervention and during a 12-week follow-up period.

RESULTS

Seven of the eight patients completed the full 12-week follow-up period. No complications were noted. Mean symptom scores declined from 27 to 12.1 (P < 0.01), whereas the SF-36 physical functioning domain also improved (P < 0.05). Four patients noted an increase in insulin use of >5 units/day. Six of the seven patients gained weight (P = 0.05). Gastric emptying scan time improved in four patients.

CONCLUSIONS

Botulinum toxin injection of the pylorus is safe and improves symptoms in patients with diabetic gastroparesis. These results warrant further investigation with a large, double-blind, placebo-controlled trial.

Efficacy of botulinum toxin injection before pneumatic dilatation in patients with idiopathic achalasia

Graded pneumatic dilatation (PD) is an appropriate long-term therapy and botulinum toxin injection (BT) is a relatively short-term therapy in idiopathic achalasia. Their combination has not been previously scrutinized. This study aimed to evaluate the role of BT in enhancing the efficacy of PD with 30 mm balloons. Patients who underwent PD with 30 mm balloons after botulinum toxin injections and a group of age- and sex-matched controls who were treated only with PD were enrolled in the study. Symptom scores were taken before, 1 month after and then every 3 months after PD. There were no significant differences between the two groups in gender, duration or severity of symptoms. One of the 12 patients in the case group relapsed 30 months after PD but the others were in remission for an average of 25.6 months. In the control group, all the patients relapsed after a mean of 12.6 months and needed a 35-mm PD. The cumulative remission rate was significantly higher in the case group compared with the control group (P < 0.01). The mean symptom score decreased by 76% in the case group (P < 0.001) and 53% in the controls (P < 0.01) at the end of the first month. Neither age, sex, nor duration or severity of symptoms were predictive of patients' responses to treatment. It seems that BT may be a meaningful enhancing factor in long-term efficacy of PD. PD with a 30 mm balloon after a BT session may resolve the need for the future higher grade PD.

Dysphagia

Dysphagia is a common complaint that always warrants investigation. The patient's history and preliminary testing can help differentiate between the two types of dysphagia: oropharyngeal or esophageal. Specific treatments for either of these types of dysphagia depend on the underlying etiology. Oropharyngeal dysphagia is often associated with a neuromuscular disorder and is treated with swallowing rehabilitation. Esophageal dysphagia is usually due to an anatomic defect or a motility disorder. Anatomic defects can often be corrected with endoscopic or surgical procedures. Motility disorders often benefit from pharmacologic treatment. Achalasia may be corrected with an endoscopic procedure with pneumatic dilation or, more recently, with injection of botulinum toxin.

Laparoscopic esophagomyotomy for achalasia: does anterior hemifundoplication affect clinical outcome?

OBJECTIVE

To determine whether the addition of anterior hemifundoplication to laparoscopic esophagomyotomy for achalasia yields better clinical outcomes than laparoscopic esophagomyotomy alone.

SUMMARY BACKGROUND DATA

Although hemifundoplication may prevent gastroesophageal reflux after esophagomyotomy for achalasia, it may also lead to persistent dysphagia in these patients with esophageal aperistalsis.

METHODS

This is a retrospective study of 51 consecutive patients (mean age 47.5 +/- 12.6 years) who had laparoscopic esophagomyotomy for achalasia by our group between August 1995 and January 2001. In 29 patients (57%) an anterior hemifundoplication was added to the esophagomyotomy. In 22 patients (43%), no wrap was added. Patients scored (0 = none; 1 = mild; 2 = moderate; 3 = severe) symptom severity (dysphagia, regurgitation, heartburn, chest pain) preoperatively and postoperatively. Weight gain, use of gastrointestinal (GI) medication, tolerance to food, and patient satisfaction were also assessed.

RESULTS

Mean patient follow-up was 33 months, and there were no operative deaths. Four patients were converted to open operation (8%). The wrap and no wrap groups were similar in terms of esophageal dilation, preoperative symptom severity and duration (5.7 +/- 7.1 versus 6.1 +/- 7.0 years), and preoperative weight loss (18 +/- 15 versus 20 +/- 20 pounds). Both groups had similar improvement in symptom grade postoperatively and equivalent satisfaction rates (86%). Postoperative weight gain, GI medication use, and food intolerance was also similar. Postoperatively, patients in the wrap group did not have higher dysphagia scores or lower heartburn scores than the no wrap group.

CONCLUSION

The addition of anterior hemifundoplication to esophagomyotomy for achalasia does not improve or worsen clinical results.

Botulinum toxin in clinical practice

Botulinum toxin, the most potent biological toxin, has become a powerful therapeutic tool for a growing number of clinical applications. This review draws attention to new findings about the mechanism of action of botulinum toxin and briefly reviews some of its most frequent uses, focusing on evidence based data. Double blind, placebo controlled studies, as well as open label clinical trials, provide evidence that, when appropriate targets and doses are selected, botulinum toxin temporarily ameliorates disorders associated with excessive muscle contraction or autonomic dysfunction. When injected not more often than every three months, the risk of blocking antibodies is slight. Long term experience with this agent suggests that it is an effective and safe treatment not only for approved indications but also for an increasing number of off-label indications.

Safety of botulinum toxin type A: a systematic review and meta-analysis

OBJECTIVE

To define quantitatively the safety and tolerability profile of botulinum toxin type A (BTX-A) across all common therapeutic indications. The review was limited to the evaluation of the safety profile of one preparation of BTX-A (BOTOX) because distinct formulations of BTX-A are associated with different clinical profiles, requiring separate consideration for an analysis of safety.

RESEARCH DESIGN AND METHODS

We identified randomized controlled trials of BTX-A through searches of the MEDLINE, EMBASE, and Cochrane Controlled Trial databases for the years 1966-2003. Studies were double-blind, randomized, crossover, or of parallel group design. The search strategy included the terms 'botulinum toxin', 'therapeutic use', 'randomized controlled trial', 'controlled clinical trial', 'randomized clinical trial', and 'placebo controlled trial'. Only randomized controlled trials of at least 7 days duration that reported adverse events were included in the analysis.

MAIN OUTCOME MEASURE

Safety was assessed by means of a meta-analysis of the number and frequency of adverse events.

RESULTS

Thirty-six studies involving 2309 subjects met the inclusion criteria. These reported on 1425 subjects receiving BTX-A treatment. No study reported any severe adverse events. The meta-analysis of any mild to moderate adverse events showed a rate of roughly 25% in the BTX-A-treated group (353/1425 patients) compared with 15% in the control group (133/884 patients, p < 0.001). Focal weakness was the only adverse event that occurred significantly more often with BTX-A treatment than control.

CONCLUSION

The results of this meta-analysis and experience from long-term, open-label investigations demonstrate that the formulation of BTX-A evaluated here has a favorable safety and tolerability profile across a broad spectrum of therapeutic uses.

Randomized controlled trial of botulinum toxin versus laparoscopic heller myotomy for esophageal achalasia

OBJECTIVE

To compare laparoscopic cardia myotomy and fundoplication with botulinum toxin (BoTx) injection in patients with esophageal achalasia.

SUMMARY BACKGROUND DATA

Although myotomy is thought to offer better results, recent studies have reported 80% success rates after 2 BoTx injections a month apart. No randomized controlled trials comparing the 2 treatments have been published so far.

MATERIALS AND METHODS

Newly diagnosed achalasia patients were randomly assigned to BoTx injection or laparoscopic myotomy. Symptoms were scored; lower esophageal sphincter resting and nadir pressures were measured by manometry; barium swallow was used to assess esophageal diameter pre- and post-treatment. Eight to one hundred units of BoTx were injected twice, a month apart, at the esophagogastric junction. Myotomy included anterior partial (Dor) or Nissen fundoplication.

RESULTS

Eighty patients were involved in the study: 40 received BoTx and 40 underwent myotomy. Mortality was nil. One surgical patient bled from the trocar site. Median hospital stay was 6 days for surgery; BoTox patients were treated as day-hospital admissions. All patients completed the follow-up. After 6 months, the results in the 2 groups were comparable, although symptom scores improved more in surgical patients (82% confidence interval [CI] 76-89 vs. 66% CI 57-75, P < 0.05). The drop in lower esophageal sphincter pressure was similar in the 2 groups; the reduction in esophageal diameter was greater after surgery (19% CI 13-26 vs. 5% CI 2-11, P < 0.05). Later on, symptoms recurred in 65% of the BoTx-treated patients and the probability of being symptom-free at 2 years was 87.5% after surgery and 34% after BoTx (P < 0.05).

CONCLUSION

Laparoscopic myotomy is as safe as BoTx treatment and is a 1-shot treatment that cures achalasia in most patients. BoTx should be reserved for patients who are unfit for surgery or as a bridge to more effective therapies, such as surgery or endoscopic dilation.

Behandlung der Achalasie

Achalasia is a condition of unknown etiology. It represents a motor disorder of the esophagus characterized by absent or incomplete relaxation of the lower esophageal sphincter upon swallowing and by non-propulsive swallow-induced contraction waves or amotility of the esophageal body. Dysphagia and regurgitation of ingesta are the most frequent symptoms. Medical treatment, i.e. by calcium-channel blockers and nitric oxide donors, may be tried in patients with mild dysphagia or in elderly patients but rarely yields adequate symptom relief. Mechanical dilatation of the achalasic sphincter may be performed as an initial treatment option. Intrasphincteric injections of botulinum toxin seemed to be a promising alternative, but it has become obvious that, in most cases, repeated applications of the toxin are required to maintain patients symptom-free. Myotomy of the achalasic sphincter with or without fundoplication to prevent gastroesophageal reflux, is employed mainly in patients in whom dilatations have failed, but since the introduction of minimally invasive surgery, myotomy has become the primary treatment at many centers. This article aims to provide an overview of the development of the conservative and surgical treatment of achalasia.

Prolonged effect of botulinum toxin injection in the treatment of cricopharyngeal dysphagia: case report and literature review

Cricopharyngeus (CP) muscle spasm can lead to severe dysphagia. Myotomy of the CP muscle was the treatment of choice. Recently, botulinum toxin type A (BtxA) has been used for CP spasm. It usually brings improvement in deglutition but most patients require reinjection in 3-5 months. We report a 35-year-old man who had an arteriovenous malformation hemorrhage in the brain stem resulting in CP spasm and consequently severe dysphagia. He received BtxA injection and deglutition and nutrition remained good one year after treatment. A literature review analyzing 28 patients and our patient showed negative correlations between age and BtxA dose and between age and duration. Efficacy was positively correlated with duration and BtxA dose was positively correlated with pretreatment severity. In conclusion, physicians would use higher doses on patients with more severe cases but use lower doses on older patients. Those who obtained better post-treatment results would enjoy longer effective duration. Thus, the effective duration of the BtxA is multifactorial.

Early results of laparoscopic Heller myotomy do not necessarily predict long-term outcome

BACKGROUND

We sought to evaluate how patients' symptoms evolve after laparoscopic Heller myotomy.

METHODS

Before and after laparoscopic Heller myotomy, 88 patients graded dysphagia and heartburn on a Likert scale (0 = none; 5 = severe). Patients graded outcomes as excellent, good, fair, or poor. Outcomes were compared in the same patients at 1 and 3 years of follow-up.

RESULTS

At early follow-up (10.6 +/- 7.8 months) significant reductions were noted in dysphagia (11% versus 100%), dysphagia scores (0.6 +/- 1.1 versus 4.7 +/- 0.7), heartburn (31% versus 72%), and heartburn scores (1.2 +/- 1.6 versus 2.7 +/- 1.9). By late follow-up (37.6 months +/- 18.0) these values increased (47%, 1.9 +/- 1.7, 48%, 1.8 +/- 1.5, respectively) but remained significantly reduced compared with before operation. Excellent/good outcomes at early and late follow-up were 89% and 85%, respectively (P = not significant).

CONCLUSIONS

Laparoscopic Heller myotomy is highly effective at palliating the symptoms of achalasia. With time, symptoms may recur owing to esophageal dysmotility, mandating continued surveillance.

Review article: the management of pelvic floor disorders

Anorectal disorders, such as faecal incontinence, defecation difficulty and conditions associated with anorectal pain, are commonly encountered in the practices of gastroenterologists, urogynaecologists and colorectal surgeons. The evaluation of these disorders has been very much improved by the development and wider availability of diagnostic tests, such as manometry, endo-anal ultrasound, static and dynamic pelvic magnetic resonance imaging and electromyography. After briefly reviewing the normal anatomy and physiology of the anorectum, the pathophysiology and diagnostic approaches to faecal incontinence, defecation disorders and functional anorectal pain are discussed. Until recently, the management of these disorders has been largely anecdotal. However, our therapeutic armamentarium has been expanded by pharmacological agents, such as nitrates, calcium channel blockers and botulinum toxin, as well as the development of novel techniques, such as sacral nerve stimulation. These and other pharmacological, behavioural and surgical approaches are reviewed with respect to the robustness of evidence to support their efficacy in patients with these disorders.

Current and future treatment of chest pain of presumed esophageal origin

Patients with chest pain of presumed esophageal origin should be reassured and should undergo an esophageal manometry study. In patients with spastic esophageal disorders, a trial with calcium channel blockers or low-dose antidepressants used as visceral analgesics is the best approach. Inpatients with non GERD-related, nonspastic esophageal motility disorder, low-dose antidepressants seem reasonable. Anxiolytics are useful in patients with panic disorders, and psychological interventions (eg, cognitive-behavioral therapy) are also valuable, mainly in patients in whom reassurance is not sufficient to avoid the misinterpretation of their symptoms. In the future, visceral sensitivity modifying agents such as serotoninergic agonists or antagonists may become the cornerstone of therapy in patients with chest pain of presumed esophageal origin. Combinations of different approaches, such as proton pump inhibitors and psychotropic or antinociceptive agents, should also be evaluated in clinical trials.

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.

Randomized controlled trial of botulinum toxin versus laparoscopic heller myotomy for esophageal achalasia

OBJECTIVE

To compare laparoscopic cardia myotomy and fundoplication with botulinum toxin (BoTx) injection in patients with esophageal achalasia.

SUMMARY BACKGROUND DATA

Although myotomy is thought to offer better results, recent studies have reported 80% success rates after 2 BoTx injections a month apart. No randomized controlled trials comparing the 2 treatments have been published so far.

MATERIALS AND METHODS

Newly diagnosed achalasia patients were randomly assigned to BoTx injection or laparoscopic myotomy. Symptoms were scored; lower esophageal sphincter resting and nadir pressures were measured by manometry; barium swallow was used to assess esophageal diameter pre- and post-treatment. Eight to one hundred units of BoTx were injected twice, a month apart, at the esophagogastric junction. Myotomy included anterior partial (Dor) or Nissen fundoplication.

RESULTS

Eighty patients were involved in the study: 40 received BoTx and 40 underwent myotomy. Mortality was nil. One surgical patient bled from the trocar site. Median hospital stay was 6 days for surgery; BoTox patients were treated as day-hospital admissions. All patients completed the follow-up. After 6 months, the results in the 2 groups were comparable, although symptom scores improved more in surgical patients (82% confidence interval [CI] 76-89 vs. 66% CI 57-75, P < 0.05). The drop in lower esophageal sphincter pressure was similar in the 2 groups; the reduction in esophageal diameter was greater after surgery (19% CI 13-26 vs. 5% CI 2-11, P < 0.05). Later on, symptoms recurred in 65% of the BoTx-treated patients and the probability of being symptom-free at 2 years was 87.5% after surgery and 34% after BoTx (P < 0.05).

CONCLUSION

Laparoscopic myotomy is as safe as BoTx treatment and is a 1-shot treatment that cures achalasia in most patients. BoTx should be reserved for patients who are unfit for surgery or as a bridge to more effective therapies, such as surgery or endoscopic dilation.

Cost-assessment of alternative management strategies for achalasia

Achalasia is a primary oesophageal motor disorder characterised by the abnormal relaxation of the lower oesophageal sphincter (LES) and absent oesophageal peristalsis. It is a rare disease, with an estimated incidence of approximately 1/100,000 and a prevalence close to 10/100,000 [1]. Its exact aetiology remains unknown. Autoimmune, infectious, degenerative and hereditary processes have all been proposed as factors that lead to a chronic inflammatory response in the myenteric plexus, thus resulting in selective loss of inhibitory neurons [2] and failure of the LES to relax and aperistalsis in the body of the oesophagus. The most common symptoms of achalasia are dysphagia for solids and liquids, regurgitation, chest pain, weight loss and heartburn in > 90 approximately 75, 40 - 50, approximately 60, approximately 40%, respectively [3,4]. The diagnosis is based on symptoms, barium swallow and manometry. A barium oesophagram typically shows a dilated oesophagus that tapers into a 'bird-beak' at the gastro-oesophageal junction with lack of normal peristalsis on fluoroscopic evaluation. The characteristic manometric features of achalasia are abnormal LES relaxation and aperistalsis; additionally, the LES pressure is frequently high, but can also be normal. Current practice of medicine is faced with rising healthcare costs and limited budgets [5]. We are therefore confronted with an increasing demand to justify the value of our therapeutic interventions, not only from the risk/benefit standpoint but also from the cost perspective [6,7].

Treatment of patients with achalasia with botulinum toxin: a multicenter prospective cohort study

Botulinum toxin (BT) injection is an alternative treatment of achalasia. The aim of the study was to examine outcomes of patients treated with BT in the Czech Republic. Since 1997, 49 patients with achalasia have been treated with BT. We prospectively evaluated the effect of BT injection on 41 patients during a median follow-up of 24 months (range 9-62). Esophageal manometry was performed before and at 3-5 months after the injection. In 16 patients, BT was injected from the antegrade angle only (subgroup A), in 15 patients, BT was injected from both retrograde and antegrade angles (subgroup B) and, in 10 patients, BT injection was combined with subsequent balloon dilatation (subgroup C). Immediate clinical response was achieved in 93% of patients. Clinical remission was sustained beyond 3 months in 83% of patients (responders). Fourteen responders (41%) did not experience a relapse during the median of 22 months. Twenty responders (59%) experienced symptomatic relapse approximately 8 months after the injection. Ten relapsers underwent BT reinjection, five (50%) of them were asymptomatic for another 14 months. The remaining five (50%) patients reported a second relapse approximately 6 months after the reinjection. Median duration of the symptom-free period was 11.5 months after the first BT injection, and 10.5 months after the second (P = 0.21). We did not find any significant predictor of a favorable outcome; responders tended to be older and to have a lower basal lower-esophageal-sphincter pressure. Patients in subgroup C were more likely to be in remission at 1 and 2 years as compared with patients in subgroup A. BT injection is an effective treatment of achalasia in the short term. However, almost 70% of patients experience a relapse within 2 years. BT injection should therefore be reserved for patients at risk for more invasive procedures or for patients who prefer this treatment.

Intrasphincteric botulinum toxin injection in the treatment of chagasic achalasia

According to the WHO, 16-18 million people in Central and South America are infected by Trypanosoma cruzi. Chagasic achalasia affects between 7.1% and 10.6% of the population. The aim of this study was to evaluate the effects of Botox injections in the clinical response and esophageal function of patients with dysphagia due to chagasic achalasia. In total, 24 symptomatic patients with chagasic achalasia were randomly chosen to receive Botulinum Toxin (BT) or saline injected by endoscopy in the lower esophageal sphincter (LES). Patients were monitored with a clinical score of dysphagia and an objective assessment (esophagograms, scintillography, manometry, and nutritional assessment) for a period of 6 months. Clinical improvement of dysphagia was statistically significant (P < 0.001) in patients receiving BT when compared with the placebo. There was no significant difference in the placebo group regarding clinical score, LES basal pressure and esophageal emptying time. Esophageal emptying time in the toxin group was significantly lower than in the placebo (P=0.04) after 90 days. There were non-significant increases in esophageal emptying of 25.36% and 17.39%, respectively, at 90 and 180 days, in the BT group (P=0.266). Gender, age, and baseline LES pressure did not influence the response to BT. Our data strongly suggests that intrasphincteric injection of BT in LES is clinically effective in the treatment of chagasic achalasia.

Effect of tensor veli palatini muscle paralysis on eustachian tube mechanics

Several physiological functions, such as regulating middle ear (ME) pressure and clearing ME fluid into the nasopharynx, require an opening of the collapsed eustachian tube (ET). The ability to perform these functions has been related to several mechanical properties of the ET: opening pressure (Popen), compliance (ETC), and hysteresis (eta). These global properties may be influenced by the mechanics of the surrounding tissue and/or the mucosa-air interface. In this study, we investigated the influence of tissue mechanics by paralyzing the right tensor veli palatini (TVP) muscle in 12 cynomolgus monkeys via botulinum toxin injection. A previously developed modified forced-response protocol was used to measure Popen, ETC, and eta under normal conditions and after muscle paralysis. The loss of muscle tone and/or stiffness resulted in a significant decrease in Popen (p < .01) and a significant increase in ETC (p < .01). In addition, muscle paralysis reduced the viscoelastic properties of the TVP muscle and therefore resulted in a significant decrease in eta (p < .05). A comparison with previous measurements on the influence of surface tension mechanics indicates that the ET's compliance is primarily determined by tissue elastic properties. The ET hysteresis, however, is equally affected by viscoelastic tissue properties and surface tension hysteretic properties. Knowledge of how these physical components affect the global mechanical environment may lead to improved treatments for ET dysfunction that target the underlying mechanical abnormality.

Inhibitory effects of botulinum toxin on pyloric and antral smooth muscle

Botulinum toxin injection into the pylorus is reported to improve gastric emptying in gastroparesis. Classically, botulinum toxin inhibits ACh release from cholinergic nerves in skeletal muscle. The aim of this study was to determine the effects of botulinum toxin on pyloric smooth muscle. Guinea pig pyloric muscle strips were studied in vitro. Botulinum toxin type A was added; electric field stimulation (EFS) was performed every 30 min for 6 h. ACh (100 microM)-induced contractile responses were determined before and after 6 h. Botulinum toxin caused a concentration-dependent decrease of pyloric contractions to EFS. At a low concentration (2 U/ml), botulinum toxin decreased pyloric contractions to EFS by 43 +/- 9% without affecting ACh-induced contractions. At higher concentrations (10 U/ml), botulinum toxin decreased pyloric contraction to EFS by 75 +/- 7% and decreased ACh-induced contraction by 79 +/- 9%. In conclusion, botulinum toxin inhibits pyloric smooth muscle contractility. At a low concentration, botulinum toxin decreases EFS-induced contractile responses without affecting ACh-induced contractions suggesting inhibition of ACh release from cholinergic nerves. At higher concentrations, botulinum toxin directly inhibits smooth muscle contractility as evidenced by the decreased contractile response to ACh.

Achalasia: a comprehensive review

Achalasia is a rare neurologic deficit of the esophagus, producing a syndrome of impaired relaxation of the lower esophageal sphincter and decreased motility of the esophageal body for which the cause is unknown. The resultant chronic esophageal stasis produces discomforting symptoms that can be managed with medication, chemical paralysis of the lower esophageal sphincter, mechanical dilation, or surgical esophagomyotomy. Chemical paralysis by injection of the esophagus with botulinum toxin and dilation with an inflatable balloon offers good short-term relief of symptoms; however, the best long-term results are produced by surgery, and advancing minimally invasive techniques continually reduce the morbidity of these operations. The type of surgical procedure, the necessity for fundoplication, and the order of treatment continue to be unresolved issues, but prospective evaluation with objective followup should allow us to provide the optimal treatment regimen to our patients.

Review article: botulinum toxin in the therapy of gastrointestinal motility disorders

Since 1980, botulinum toxin has been employed for the treatment of various voluntary muscle spastic disorders in the fields of neurology and ophthalmology. More recently, botulinum toxin has been proved to be effective in the therapy of dyskinetic smooth muscle disorders of the gastrointestinal tract. Achalasia and anal fissure are the gastrointestinal disorders in which botulinum toxin therapy has been most extensively investigated. Botulinum toxin is the best treatment option for achalasia in patients whose condition makes them unfit for pneumatic dilation or surgery. In anal fissure, botulinum toxin is highly effective and may become the treatment of choice. In the future, botulinum toxin application in the gastrointestinal tract will be extended to many other gastrointestinal disorders, such as non-achalasic motor disorders of the oesophagus, dysfunction of Oddi's sphincter, achalasia of the internal anal sphincter and others. This article describes the mechanism of action, rationale of employment, indications and side-effects of botulinum toxin application in smooth muscle disorders of the gastrointestinal tract, and compares the results of different techniques of botulinum toxin therapeutic application.