Management of defecation disorders with botulinum neurotoxin

Bilateral versus unilateral botulinum toxin injections for chronic anal fissure: a randomised trial

BACKGROUND

Botulinum toxin injected into the internal anal sphincter is used in the treatment of chronic anal fissure but there is no standardised technique for its administration. This randomised single centre trial compares bilateral (either side of fissure) to unilateral injection.

METHODS

Participants were randomised to receive bilateral (50 + 50 units) or unilateral (100 units) Dysport® injections into the internal anal sphincter in an outpatient setting. Injection-related pain assessed by visual analogue scale was the primary outcome measure. Secondary outcomes were healing rate, fissure pain, incontinence, and global health scores.

RESULTS

Between October 2008 and April 2012, 100 patients with chronic anal fissure were randomised to receive bilateral or unilateral injections. Injection-related pain was comparable in both groups. There was no difference in healing rate. Initially, there was greater improvement in fissure pain in the bilateral group but at 1 year the unilateral group showed greater improvement. Cleveland Clinic Incontinence score was lower in the unilateral group in the early post-treatment period and global health assessment (EuroQol EQ-VAS) was higher in the unilateral group at 1 year.

CONCLUSIONS

Injection-related pain was similar in bilateral and unilateral injection groups. Unilateral injection was as effective as bilateral injections in healing and improving fissure pain without any deterioration in continence.

Botulinum Toxin A for Controlling Obesity

Rapid growth of the overweight population and the number of obese individuals in recent decades suggests that current strategies based on diet, exercise, and pharmacological knowledge are not sufficient to address this epidemic. Obesity is the result of a high caloric intake and energy storage, not counterbalanced by an equally important energy expense. Botulinum toxin type A (BoNT-A) use is rapidly expanding to include treatment of a variety of ophthalmological, gastrointestinal, urological, orthopedic, dermatological, secretory, painful, and cosmetic disorders. Many studies evaluating the effect of BoNT-A in gastric antrum e/o fundus for the treatment of obesity have been published. This treatment modality was based on the observation that gastric injection of BoNT-A in laparatomized rats induced a significant reduction of food intake and body weight. These studies have been published yielding debated results. Differences in the selection of patients, the doses of BoNT-A, the method of administration of the toxin, and the instruments of evaluation of some parameters among these studies may be the cause. In this review, it will study the state-of-the-art use of BoNT-A in obesity basic science models and review the clinical evidence on the therapeutic applications of BoNT-A for obesity.

Endoscopic botox injections in therapy of refractory gastroparesis

Gastroparesis (GP) is a common disease seen in gastroenterology practice particularly in western countries, and it may be underdiagnosed. The available drug therapies for this condition are quite disappointing. Botulinum toxin type A (BT) has been found to be effective therapy in various spastic disorders of smooth muscle of gastrointestinal tract. However, the benefits of BT injections in GP have been unclear. Several retrospective and open label studies have shown clinical advantages of intrapyloric Botulinum toxin type A injections, while two small randomized trials did not show positive results. Therefore, the available published studies yielded conflicting results leading to fading out of botox therapy for GP. We recognize possible clinical benefit of BT injections without any disadvantages of this treatment. We are calling for revisiting the endoscopy guided botox therapy in refractory GP. In this review we discuss important features of these studies pointing out differences in results among them. Differences in patient selection, doses and method of administration of botox toxin in the prior studies may be the cause of conflicting results. The mechanism of action, indications, efficacy and side-effects of BT are reviewed. Finally, we recognize limited evidence to recommend BT in GP and calling attention for future research in this field since no advances in drug management had been made in the last two decades.