Role of botulinum toxin A injection into the submandibular salivary glands as an assessment for the subsequent removal of the submandibular glands in the management of children with sialorrhoea

Sialorrhoea is caused by an excessive production of saliva or a lack of muscular coordination at the initiation of the swallowing reflex during the voluntary phase. In children with neuromuscular disorders it can cause excoriation and social embarrassment. In adults, repeated injections of botulinum have been shown to be beneficial in the control of sialorrhoea, but in children, lack of cooperation necessitates general anaesthesia, and repeated injections would not be appropriate. We aimed to assess outcome after injection of botulinum into the submandibular glands to find out whether subsequent removal of the glands would reduce salivary flow to an acceptable level. We assessed 30 children with various neuromuscular disorders that caused a lack of muscular coordination when swallowing. Under general anaesthesia, they all had injection of 1 unit/kg/gland of botulinum toxin A (Dysport™, Ipsen Ltd., Slough, UK) into each submandibular gland either by bimanual palpation or under ultrasound guidance. They were reassessed at 6 weeks to find out whether the flow had reduced adequately or whether the mouth was too dry. Twenty-one had improved and of these, 20 went on to have the glands removed successfully with no neurological or surgical complications. The mouth of one patient had become too dry after injection and the parents declined further surgery. The remaining 9 did not improve noticeably and continued to be managed medically.Injection of botulinum into the submandibular glands gives a reliable assessment of how much the salivary flow will be reduced after the submandibular gland has been removed.