Vaginismus is the recurrent or persistent involuntary contraction of the perineal muscles surrounding the outer third of the vagina when penile, finger, tampon, or speculum penetration is attempted.1 Vaginismus can be primary, meaning the women has never been able to have intercourse, or secondary, which is often due to acquired dyspareunia. It is relatively rare, affecting about 1% of women.2 Treatment of vaginismus is directed toward extinguishing the conditioned involuntary vaginal spasm. This can be accomplished by teaching Kegel exercises to acquaint the patient with voluntary control of her levator muscles. Medications such as lubricants, anesthetic creams, propranolol, or alprazolam, to reduce anxiety, have been used effectively,3 but approximately 10% of patients do not respond. Botulinum toxin type A has been successfully used to treat a wide range of muscle disorders such as strabismus, blepharospasm, and cervical dystonia. It is also been used to reduce facial lines and wrinkles. The purpose of this study was to investigate the effect of this drug on vaginal spasm in patients with severe and refractory vaginismus.
MATERIALS AND METHODS
The Research and Ethics Committee of Tehran University of Medical Sciences approved the study. From February 2002 to February 2004, 24 women were referred to our clinic with third- or fourth-degree vaginismus (grade 3: 37.5%; grade four: 62.5%) according to the Lamont classification (Table 1). 4 The women were enrolled in the study after giving informed consent. None had a contraindication to botulinum toxin. Contraindications included hypersensitivity to albumin, botulinum toxin, or any component of the formulation; infection at the proposed injection site(s); pregnancy; diseases of neuromuscular transmission; and coagulopathy or therapeutic anticoagulation.
The mean age of the participants was 25 years (range 19–34 years). The women were married for a mean of 33.71 months (range, 1 month to 13 years). All patients had received different types of treatment, including behavior therapy techniques such as deep muscle relaxation exercises, anesthetic creams, and vaginal lubricants; 5 patients had history of surgery to incise the rigid hymen
The procedure was performed in a day clinic unit. A vial of 500 U botulinum toxin type A (Dysport; Ipsen Ltd, United Kingdom) was diluted with 1.5 mL of normal saline solution. A total dose of 150–400 U was equally injected in the levator ani (puborectalis muscles), 3 points on each side (Fig. 1), with a 23-gauge needle. Because most of our patients had severe vaginismus (62.5%), before attempting this injection, we administered light sedation of 1–5 mg midazolam and 50–150 mg fentanyl. Oxygen (6–8 L/min) was given via face mask. Monitoring of Spo2 was done via pulse oximetry. The sedation was not deep; some extent of muscular contraction was required to be visible to find the exact location of muscles for injection. We used the lowest dose (150–200 U) for our first cases to ensure the safety of the drug. Because we had partial response in some patients, we gradually increased the total dose to 400 U in subsequent cases. Patients were discharged on the same day. They were followed up after 1 week to check the vaginal muscle resistance, and were then followed up for a mean of 12.37 months (range 2–24 months). We used SPSS 11.5 (SPSS Inc, Chicago, IL) to analyze the data.
There were no complications during or after the injection. No patient reported side effects (eg, dry mouth, fecal or urinary incontinence). One patient refused to undergo a vaginal examination, and stated that she could easily put her finger inside her vagina but did not attempt to have coitus. Twenty-three patients (95.8%) had a vaginal examination that showed no or little resistance, 18 (75%) achieved satisfactory intercourse after the first injection, 4 (16.7%) had mild pain, and 1 was cured after a second injection. Another patient had no coitus because of secondary impotence in her husband, and she is planning to receive a second injection after her husband has been treated.
There were no cases of recurrent vaginismus. All patients said that they would recommend this treatment for similar patients.
The term “vaginismus” was originally used in 1862 by Dr. Marion Sims to describe a reflex-like contraction of the circumvaginal musculature, resulting in nonconsummation of marriage.5 The edge of the puborectalis or pubococcygeus muscle impinges on the lateral wall of the vagina about 1.5–2 inches above the hymen. Patients characteristically describe the involuntary spasm of these muscles during attempts at insertion of the penis.
More recently, vaginismus has been described as an involuntary spasm of the pelvic floor muscles and perineal muscles that surround the outer third of the vagina that makes intercourse uncomfortable or impossible. This involuntary spastic contraction is a reflex response that is stimulated by imagined, anticipated, or real attempts at vaginal penetration.6 In severe cases of vaginismus, the abductors of the thighs, the rectus abdominis, and the gluteus muscles also may be involved. Vaginismus can be global, in which case the woman is unable to place anything inside her vagina, or situational, in which case she can use a tampon and tolerate a pelvic examination but cannot have intercourse.3
Botulinum toxin type A is a neurotoxin produced by Clostridium botulinum, a spore-forming anaerobic Bacillus, which appears to affect only the presynaptic membrane of the neuromuscular junction in humans, where it prevents calcium-dependent release of acetylcholine and produces a state of denervation. Muscle inactivation persists until new fibrils grow from the nerve and form junction plates on new areas of the muscle-cell walls.
Botulinum toxin paralyzes muscles by the prevention of acetylcholine release. The extent of paralysis depends on the amount of toxin to which there is exposure relative to muscle bulk.7 The neuromuscular blockade is permanent, and recovery of function results from the establishment of new neuromuscular junctions by a process of terminal axonal and nodal sprouting. Renal, hepatic, or other diseases do not have any effect on the distribution or binding of botulinum toxin. This toxin is thought to be metabolized locally.7 The minimum dose of toxin necessary to produce systemic toxicity is not known. However, by extrapolation of animal experiments, it is estimated that 160 vials of the drug would be needed to produce systemic symptoms of toxicity.7
Since its release, botulinum toxin has been shown to be useful in treating a number of clinical conditions associated with neuromuscular dysfunction, such as focal dystonias, upper motor neuron syndromes, and muscle hyperactivity. Many of these conditions are associated with significant pain. It was observed that botulinum toxin not only treated the neuromuscular disorders, but that the associated pain appeared to be ameliorated. In a randomized trial of 31 patients with chronic low back pain, botulinum toxin type A injections were significantly better than placebo.8
When botulinum toxin is administered, important considerations include the amount injected per muscle, the total amount injected, the number of sites injected, and selection of appropriate areas to inject. The total dose and frequency should be minimized to avoid development of antibodies; however, the incidence of antibody development is low (4%).9
Our study demonstrates the effectiveness of botulinum toxin type A injection in the treatment of moderate and severe cases of vaginismus. However, other types of treatments such as behavior therapy techniques should be tried first.
In a placebo-controlled study of 13 patients, Shafik et al10 also reported complete response to botulinum toxin injection. Brin and Vapnek11 reported a case of dyspareunia complicated with interstitial cystitis that was managed with injection of botulinum toxin at 2 consecutive sessions; after a few days, the patient's symptoms resolved and she had intercourse for the first time in 8 years. There are reports of successful use of botulinum toxin in the treatment of anal fissure.12,13 For example, 30 consecutive patients with chronic anal fissure were randomized to receive intrasphincteric botulinum toxin or saline injection.14 Injection was accomplished by palpation of the internal anal sphincter and administration of a total volume of 0.4 mL (in 2 equal doses for a total of 20 U of botulinum toxin) via a 27-gauge needle close to the fissure on each side. No sedation or local anesthesia was used. After 2 months, significantly more patients who had received botulinum toxin had healed (73% versus 13%).
In conclusion, botulinum toxin may be appropriate therapy for patients with vaginismus who have failed to respond to conventional therapies. However, therapy with botulinum toxin should be considered experimental and ideally administered as part of clinical trials.
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