Introduction Enhanced recovery programs (ERP) are standard of care in colorectal surgery. Avoidance of opioid analgesia and associated postoperative adverse events (AEs) lead to shortened hospitalisation and lower costs. The addition of long-acting liposomal bupivacaine as part of multimodality pain control may decrease reliance on opioids. This study aimed to evaluate the effect of liposomal bupivacaine infiltration on total amount of opioid use, incidence of AEs and length of stay (LOS) after minimally invasive (MIS) sigmoid coloctomy.

Method A single-centre retrospective review was performed in patients undergoing a MIS sigmoid resection from 2012–2014. Patients in the intervention group received 266mg of liposomal bupivacaine in the surgical incision by a single surgeon and were matched to controls for age, gender, BMI, procedure and extraction site. Primary outcome was total opioid use in the first 72 h. Secondary outcomes included LOS, time to first flatus and bowel movement, and incidence of AEs (ileus and urinary retention). Confounding variables (i.e. ketorolac use) were determined a prioriand were accounted for. Univariate analyses included a t-test for continuous variables and a Mann-Whitney U test for non-parametric variables. Multivariable regression identified the role the intervention had in predicting the primary outcome with adjustment of confounding variables.

Results 70 patients (43% female; mean age 60 (±13) years) were included. The intervention and controls groups included 35 patients each. Diagnoses included diverticulitis (72%), colonic malignancy (14%), benign neoplasm (10%) and inflammatory bowel disease (4%). The median number of port sites was 4 (3–5), where 39% of patients had a midline extraction site vs. 61% with a Pfannenstiel. Total incision length was 9.5cm in 63% of patients. No difference in total opioid use was identified between groups (61mg vs. 70mg; p = 0.51) on univariate analysis. A sensitivity analysis was used to account for extremes in opioid use by removing the outermost 10^thpercentiles of opioid use; no difference was confirmed (59mg vs. 60mg; p = 0.98). LOS was similar in both groups (median 5 days), with no difference in AEs. There was no significant difference in time to first flatus or bowel movement (p = 0.23 and p = 0.35, respectively). A multivariate logistic regression adjusting for ketorolac and acetaminophen use demonstrated that liposomal bupivacaine did not predict total opioid use (OR 0.56–3.73; p = 0.446).

Conclusion When added to an aggressive ERP, liposomal bupivacaine does not decrease the amount of total opioid consumption, the incidence of AEs or the LOS in patients undergoing MIS sigmoid resection.

Disclosure of interest None Declared.