Intentional lateral epidural catheter placement for anterior cruciate ligament reconstruction

Background:  Unilateral epidural block might constitute a clinical option in lower limb orthopedic surgery. Methods:  Seventy-five patients undergoing anterior cruciate ligament reconstruction (ACLR) were randomized to either a laterally directed epidural catheter (IUEC, n = 40) or a classic midline catheter (CMEC, n = 35). Paresthesia encountered during catheter insertion was registered. The start dose of the anesthetic mixture clonidine 60 µg (0.4 ml), sufentanil 15 µg (0.3 ml) and ropivacaine 10 mg ml−1(10.3 ml) in 11 ml of total volume) was set at 5 ml and was increased by 2 ml if anesthesia was inadequate after assessment for sensory blockade to cold and pin-prick. Data were registered intra- and postoperatively regarding pain scores as well as motor block, hemodynamic parameters, adverse effects and need for supplemental analgesia other than a continuous postoperative epidural infusion. Results:  In the IUEC group 80% of patients reported a light paresthesia of the affected side during catheter insertion, whereas 71% of patients in the CMEC group reported no paresthesia at all. The amount of anesthetic used to establish surgical anesthesia was lower in the IUEC group (6.2 ± 0.8 vs. 8 ± 1.9 ml, P < 0.001). Motor block (Bromage score) of the unaffected side was significantly lower in the IUEC group (P < 0.001). Pain intensity scores, hemodynamic parameters, and supplemental analgesia given were similar between the two groups except for VAS scores at 12 h postoperatively, which were higher in the CMEC group (P < 0.01). Urinary retention was significantly more frequent in the CMEC group (19/35 vs. 5/40, P < 0.001). Conclusion:  These results suggest that the IUEC technique is a feasible and efficient method for providing anesthesia and analgesia for ACLR and is associated with a lower consume of anesthetics, less motor block and a reduced incidence of urinary retention.