Preoperative opioid use and the outcome of thoracoscopic splanchnicectomy in chronic pancreatitis: a systematic review

Background Thoracoscopic splanchnicectomy (TS) is a minimally invasive intervention to relieve pain in patients with chronic pancreatitis (CP) with equivocal results. Preoperative opioid use seems to impair TS outcome but this has not been investigated in a systematic matter. Methods We searched PubMed, EMBASE, and The Cochrane Library for studies on the outcome of TS in CP patients. Studies with >= 5 patients and a follow-up of >= 12 months were included. Success was defined as the proportion of patients free of opioids or who had a reduction of >= 4 points on a pain scale. The effect of opioid use on the success rate of TS was analyzed by uni- and multivariate regression. Results Sixteen studies with 484 patients were included in our review. The mean (+/- SD) age of the patients was 44 +/- 4.3 years and 66 % were male. Median follow-up period was 21 months (IQR 14-35). Median preoperative opioid use was 85 % (IQR 54-100 %). After TS, a median of 49 % (IQR 22-75 %) of patients were free of opioids at end of follow-up. The median success rate was 62 % (IQR 48-86 %). Mean success rate in studies in which <= 50 % of the patients used opioids preoperatively was 81 % (SD +/- 21) compared to 60 % (SD +/- 15) for other studies (p = 0.049). Higher age, male gender, and lower rates of preoperative opioid use were associated with a higher success rate (p = 0.003, 0.047, and 0.017, respectively). Multivariate regression, including age, gender, preoperative opioid use, and duration of follow-up, identified age and preoperative opioid use as independent predictors of success after TS (both p = 0.002). Conclusion Preoperative opioid use is associated with a worse outcome after TS in CP patients. To optimize outcome, use of TS may be considered at an earlier stage in the treatment of patients with CP before prolonged opioid therapy.