Pre-operative opioid analgesia reduces clinical success of laparoscopic gastric electrical stimulation placement in patients with gastroparesis.

INTRODUCTION: Gastroparesis is a common chronic and costly disorder for which medical therapy is often unsuccessful. Gastric electrical stimulation (GES) has been used to treat refractory cases, however, response is variable and difficult to predict. This study aims to assess whether pre-operative opioid analgesics (OA) use affects clinical success of GES.
METHODS: Records of 128 patients who underwent laparoscopic GES placement from March 2001 to September 2012 were analyzed retrospectively. Data collected included demographics, surgical outcomes, and clinical parameters. Pre- and post-operative opioid analgesic dosing (No = 0 morphine equivalents (ME)/day, Low = 0-40 ME/day, Mid = 41-80 ME/day, High >80 ME/day), as well as clinical symptom assessment was collected for up to 3 years post-operatively. Clinical success was defined as (1) OA reduction of >50 %, (2) maintenance of weight, or (3) symptom improvement. Descriptive statistics were computed for all factors. A p < 0.05 was considered statistically significant.
RESULTS: Fifty-three patients were on OA pre-operatively compared to 69 patients who were not. Patients not on OA pre-operatively were less likely than those on OA pre-op group to be on OA post-operatively (p = 0.005); however, there were no differences in weight or symptom improvement. Sub-group analysis of the 53 patients on OA demonstrated significant improvement in clinical symptoms in the low-morphine cohort compared to the mid-morphine cohort (p = 0.02), and OA dosing post-operatively in the low-morphine cohort diminished significantly compared to mid- and high-morphine cohort (p = 0.032). There was no significant difference in weight.
CONCLUSION: OA dosing pre-operatively significantly affects clinical success of GES placement. Criteria for offering GES implantation may need to take OA dosing into consideration.