INTRASPHINCTERIC INJECTION OF BOTULINUM TOXIN FOR SUSPECTED SPHINCTEROF ODDI DYSFUNCTION

Botulinum toxin is a potent inhibitor of the release of acetylcholine from nerve endings. It has previously been shown that it can effective ly reduce lower oesophageal sphincter pressures both in animals and hu mans with achalasia. This examined the hypothesis that injected botuli num toxin could also reduce sphincter of Oddi pressure in patients wit h sphincter of Oddi dysfunction. Two patients with postcholecystectomy pain syndrome were diagnosed with sphincter of Oddi dysfunction (by b iliary manometry in one patient and by hepatobiliary scanning criteria in the other). Botulinum toxin was injected into the sphincter of Odd i, by a sclerotherapy needle passed through a duodenoscope. In the fir st patient, intrasphincteric injection of botulinum toxin reduced sphi ncter pressure by about 50%, an effect that was sustained for at least four months. In the second patient, intrasphincteric injection caused about a 50% improvement in bile flow, with normalisation of scintigra phy. Neither patient showed any sustained improvement in pain despite these objective findings. Both patients eventually had endoscopic sphi ncterotomy, which also did not result in symptomatic improvement in ei ther patient. No side effects were seen. Intrasphincteric botulinum to xin is a simple and effective means of lowering sphincter of Oddi pres sure. This technique has potential for being useful clinically.