a 58-year - old woman visited our pain clinic for consideration of a splanchnic nerve block . , she suffered from chronic recurrent abdominal pain and underwent repeated multiple abdominal work - ups and hospitalization . after several trials of endoscopic retrograde cholangiopancreatography , the patient was diagnosed as having sod . her visual analog scale ( vas ) score for pain intensity was 8 - 9/10 . pain relief was not achieved by numerous medications including opioids , anticonvulsants , antidepressants , and others . medications included 40 mg of oxycodone at every 8 hrs , a fentanyl citrate patch , 150 mg of tramadol at every 12 hrs , 200 g of fentanyl oral tablets at prn , 1,000 mg of gabapentin at every 8 hrs , and 50 mg of milnacipran at every 12 hrs . endoscopic sphincterotomy was recommended for the patient by a gastroenterologist , but the result of an endoscopic sphincterotomy was disappointing . therefore , a splanchnic nerve block was performed with local anesthetics and corticosteroid , providing a benefit for a short duration . this was followed by splanchnic nerve destruction with 100% dehydrated alcohol , and the patient was satisfied with the result . the procedure was repeated three times in two years , but the duration of the effect was reduced gradually , and the last procedure did not reduce the pain at all . the patient did not respond to numerous medications , nor did splanchnic nerve block help . it was difficult for her to live a normal life due to pain , and she fell into depression . we decided to proceed with a trial of spinal cord stimulation which utilized a percutaneous octopolar catheter - type lead ( octrode lead , advanced neuromodulation systems , plano , tx , usa ) . the trial scs lead was placed at the t5 - 7 level corresponding to the painful area . during the trial , after this successful trial , a permanent percutaneous octopolar catheter - type lead was placed at the t5 - 7 level ( fig . the stimulation parameters were a pulse width of 450 s , amplitude of 6.0 ma and a frequency of 60 hz . postoperative medication included 40 mg of oxycodone , 400 mg of gabapentin at every 8 hrs , and 50 mg of milnacipran at every 12 hrs when she finally visited our pain clinic . the patient was followed - up with for more than six months , and she demonstrated excellent improvement in pain without complications . three clinical categories may cause sod symptoms : post - cholecystectomy syndrome , acalculous biliary pain with an intact gallbladder , and recurrent idiopathic pancreatitis . the prevalence of sod in patients after cholecystectomy is 1% , but it is 14 - 23% in patients with post - cholecystectomy syndrome ( biliary pain with elevated liver enzymes ) . the milwaukee classification classifies sod according to clinical characteristics based on elevated liver enzymes , a dilated common bile duct and the presence of abdominal pain . type i sod patients have abdominal pain , abnormal liver enzymes and a dilated common bile duct . a diagnosis of sod requires a strong suspicion of the disease after ruling out anatomical causes . manometry of the sphincter of oddi is the most objective and direct diagnostic method of sod . however , invasive diagnostic techniques such as manometry have limited availability given the risk of potential complications . medical treatment of sod includes smooth muscle relaxants and calcium channel blockers , but the effectiveness of these agents is limited . there are a few reports which found that a medical treatment with trimebutine and nitrates is as effective as surgical treatment . however , thus far the most effective treatment of sod is endoscopic sphincterotomy . despite the availability of extensive pharmacologic , physical therapeutic , surgical , and cognitive- behavioral treatments endoscopic sphincterotomy was also performed for the patient in this study , but she did not experience a decrease in vas scores for pain intensity . the pain from a visceral origin is classically described as poorly localized with dull , cramping characteristics . it is produced by stimuli different from those adequate for the activation of somatic nociceptors . adequate stimuli for the production of visceral pain include the distention of hollow organs , traction on the mesentery , ischemia , and chemicals typically associated with inflammatory processes . it is associated with emotional and autonomic responses typically greater than those associated with somatic pain . a hypothesis that scs is gating visceral nociception at the spinal level , i.e , the " gate theory " of melzack and wall , has been proposed . scs is promoting the descending inhibitory pathway which acts via the supraspinal mechanism by pretectal nucleus stimulation . case series which have gained good results about ventral epidural space scs in patients suffering from visceral pain have been reported , suggesting that there may be another mechanism of action for the effect of scs . scs has been applied to patients with intractable pain syndrome as an effective treatment modality and its indications have been expanded . many studies about scs as a treatment for neuropathic pain have been reported , and complex regional pain syndrome is the disease most commonly treated with scs . recently , case reports of patients successfully treated for visceral pain with scs have increased . the initial report of scs for visceral pain published by ceballos et al .   described a 78-year - old man with mesenteric ischemia who was not determined to be a surgical candidate for revascularization . since the first clinical trial , neuromodulation has been applied to chronic pancreatitis , pelvic visceral pain , angina chest pain , crohn 's disease , endometriosis and irritable bowel syndrome . scs lead placement varies from c3 to t12 , and the " sweet spot " also varies compared with extremity pain , even when the pain is in a similar site . decreased vas scores for pain intensity , a reduction of opioid consumption , and the recovery of daily life activities were described in previous studies . however , the effectiveness of the scs treatment is not proven because there is no randomized controlled trial comparing scs with a conventional treatment . in addition , results from long - term follow - up also have not been reported . scs as a treatment for visceral pain involves complications , like other etiology cases , such as infection , lead migration , and unpleasant stimulation to extremities . therefore , scs is not the first line of treatment for visceral pain , but it is worth applying for chronic intractable patients who do not respond to conventional treatment methods as an alternative treatment option . after an application of permanent scs , the vas score for pain intensity of the patient was reduced to 2 - 3/10 , and the pain was well controlled for six months without significant complications . scs may provide moderate pain relief with an improved quality of life and less consumption of analgesics for patients with sod . we report the application of scs as an alternative treatment option for chronic intractable visceral pain due to sod .
sphincter of oddi dysfunction ( sod ) is a syndrome of chronic biliary pain or recurrent pancreatitis due to the functional obstruction of the pancreaticobiliary flow . 
 we report a case of spinal cord stimulation ( scs ) for chronic abdominal pain due to sod . 
 the patient had a history of cholecystectomy and had suffered from chronic right upper quadrant abdominal pain . 
 the patient had been diagnosed as having sod . 
 the patient was treated with opioid analgesics and nerve blocks , including a splanchnic nerve block . 
 however , two years later , the pain became intractable . 
 we implanted percutaneous scs at the t5 - 7 level for this patient . 
 visual analog scale ( vas ) scores for pain and the amount of opioid intake decreased . 
 the patient was tracked for more than six months without significant complications . from our clinical case 
 , scs is an effective and alternative treatment option for sod . 
 further studies and long - term follow - up are necessary to understand the effectiveness and the limitations of scs on sod .