Background and aims Common delivery systems for perineural catheter placement use catheters inserted through—or over—a straight, hollow-bore needle. A new delivery system uses a suture-shaped needle to pull the catheter adjacent to the target nerve then out through the skin. With the catheter secured at two sites, local anesthetic is infused via an orifice.

Methods This study was IRB approved and prospectively registered (NCT03442036). Subjects having painful foot/ankle surgery were randomized to through-needle (TN) or suture-catheter (SC) placement proximal to the sciatic bifurcation. Lidocaine was administered via the catheter and patients subsequently received a 3-day ropivacaine. The primary hypothesis was that surgical pain would be noninferior within the first 2 days with the SC compared with the TN technique. The final analysis is pending, so we report here the preliminary findings using a Mann Whitney analysis.

Results Average pain scores (median [interquartile]) during the first 2 postoperative days were 2.0 [0.6–4.4] for SC group vs. 4.0 [1.0–5.0] for TN group (p=0.038). While the number of opioid tablets required was lower in SC group, this difference did not reach statistical significance (p=0.125). For SC vs. TN, the proportion of subjects with sleep disturbances due to pain (30% vs. 56%, p<0.001) and leakage (0% vs. 40%, p<0.001) was lower; but dislodgements were similar (0 vs. 2 for the first 2 days, p=0.150).

Conclusions Postoperative analgesia was not only noninferior, but superior within the first 2 days following painful foot/ankle surgery with a suture-method compared with a through-the-needle perineural catheter when used for a continuous popliteal-sciatic nerve block.