Femoral nerve blockade during endovenous laser ablation of great saphenous vein decreases pain but does not affect the use of opioids during the procedure

Abstract

BackgroundEndovenous laser ablation (EVLA) using tumescent anesthesia for treatment of an insufficient great saphenous vein (GSV) can be painful and require intravenous pain management and, sometimes, sedation with propofol. Femoral nerve blockade (FNB) anesthetizes the femoral nerve distribution and is usually used for anterior thigh and knee procedures. It is easy to inject with ultrasound guidance because the nerve is easy to visualize in the groin. The aim of the present double-blind, randomized controlled trial was to determine whether FNB before tumescent anesthesia decreases the pain of GSV EVLA combined with local phlebectomy. MethodsEighty patients who underwent GSV EVLA combined with local phlebectomy under tumescent anesthesia were randomized into two groups. The placebo group (control group; 40 patients) was given placebo FNB with 0.9% saline before tumescent injection. The FNB group (intervention group; 40 patients) received 1% lidocaine with adrenaline for FNB before tumescent injection. Only the study nurse, who performed the randomization, knew which patients were in which group. The patients and operating surgeon were unaware of the randomization group. FNB was performed under ultrasound guidance. The effectiveness of anesthesia was tested 10 minutes after injection using the pin-prick test and a numeric rating scale (NRS). The NRS was completed before and during tumescent anesthesia and during EVLA ablation and local phlebectomy. The motor function of the femoral nerve was tested at the end of the procedure and 1 hour after using the Bromage method. Patients had a follow-up visit 1 month after the procedure, and their need for pain medication and the duration of sick leave were recorded. ResultsNo differences were found in the gender distribution, age, or GSV dimensions at baseline. The mean length of the treated GSV segment was 28 cm and 30 cm and the mean energy used was 1911 J and 2059 J in the placebo and FNB groups, respectively. The median NRS score for pain during tumescent injection around the GSV was 2 (interquartile range [IQR], 1-4) in the placebo group compared with 1 (IQR, 1-3) in the FNB group. Very little pain was experienced during laser ablation. The median NRS score was 0 (IQR, 0-0) and 0 (IQR, 0-0.75) in the placebo and FNB groups, respectively. The most painful stage was injection of tumescence to the local phlebectomy sites in both groups. The median NRS score was 4 (IQR, 3-7) in the placebo group and 2 (IQR, 1-4) in the FNB group (P = .01). During local phlebectomy, the NRS score was 2 (IQR, 0-4) vs 1 (IQR, 0-3) in the placebo and FNB groups, respectively. Only the difference in pain during injection of tumescence before local phlebectomy was significant. ConclusionsFNB seems to decrease pain during EVLA combined with local phlebectomy. Patients experienced the highest pain when tumescence was injected before local phlebectomy, and those in the FNB group experienced significantly less pain than the placebo group. No indication for routine use of FNB is indicated. However, it could be used to decrease the pain for patients who experience strong pain during varicose vein surgery, especially if extensive local phlebectomies are required.