Varicose veins are a common vascular disorder affecting approximately 23% of adults globally, characterized by dilated, tortuous superficial veins primarily in the lower extremities [1]. The condition results from venous hypertension secondary to valvular incompetence, leading to symptoms such as pain, heaviness, swelling, and skin changes that significantly impair quality of life [2]. Risk factors include advancing age, female gender, pregnancy, prolonged standing, and genetic predisposition [3].

Historically, surgical ligation and stripping of the great saphenous vein (GSV) was the gold standard treatment [4]. However, this approach is associated with significant morbidity, including wound complications, prolonged recovery, and recurrence rates up to 40% at 5 years [5]. The advent of endovenous thermal ablation (EVA) techniques, including endovenous laser ablation (EVLA) and radiofrequency ablation (RFA), has revolutionized management by offering minimally invasive alternatives with superior efficacy, faster recovery, and improved cosmetic outcomes [6].

EVA procedures are typically performed under local anesthesia, with tumescent anesthesia (TA) being the most widely employed technique [7]. TA involves infiltration of large volumes of dilute local anesthetic solution around the target vein, providing analgesia, compressing the vein to improve contact with the ablation device, and acting as a heat sink to protect surrounding tissues [8]. Despite these advantages, TA requires multiple needle injections along the GSV course, which can cause significant procedural pain due to the rich innervation of the medial thigh by the femoral nerve [9].

Ultrasound-guided femoral nerve block (FNB) has emerged as a promising adjunct to TA for EVA procedures [10]. By anesthetizing the femoral nerve, which supplies sensory innervation to the medial thigh and leg, FNB can potentially reduce pain during TA infiltration and ablation. Several studies have demonstrated the efficacy of FNB in improving patient comfort during venous procedures [11,12]. However, limited comparative data exist regarding the combined approach of TA with FNB versus TA alone, particularly in the context of EVA for varicose veins [13].

This study aims to evaluate and compare the efficacy of TA alone versus TA combined with ultrasound-guided FNB in patients undergoing EVA for symptomatic varicose veins. The primary objective is to assess intraoperative pain, while secondary objectives include evaluating procedure duration, postoperative analgesic requirements, time to home readiness, and complication rates. We hypothesize that the addition of FNB to TA will provide superior analgesia without compromising safety or significantly prolonging procedure time.

Study Design and Setting

A prospective randomized comparative study was conducted at the Department of General Surgery, Deen Dayal Upadhyay Hospital, New Delhi, between May 2022 and June 2024. The study protocol was approved by the institutional scientific and ethics committee, and written informed consent was obtained from all participants.

Sample Size Calculation

Based on previous research by Al Wahbi et al. [14], which reported mean VAS scores of 7.95 for TA alone and 1.08 for TA+FNB, we calculated the required sample size. Assuming a minimum clinically important difference of 1.0 on the VAS, standard deviation of 1.0, 95% power, and 95% confidence interval, the formula by Snedecor & Cochran yielded a minimum of 27 patients per group. Accounting for potential dropouts, we enrolled 30 patients per group (total n=60).

Inclusion and Exclusion Criteria

Inclusion criteria:

• Primary symptomatic varicose veins involving the GSV with incompetent saphenofemoral junction
• Age > 18 years
• American Society of Anesthesiologists (ASA) physical status I-III

Exclusion criteria:

• Requirement for general or spinal anesthesia
• Unsuitability for endovenous ablation
• Recurrent varicose veins
• Acute deep vein thrombosis
• Known hypersensitivity to local anesthetics

Randomization and Group Allocation

Block randomization with sealed envelope technique was employed. Sixty opaque envelopes contained treatment allocations (TA alone or TA+FNB) in blocks of ten. Upon enrollment, an envelope was opened to assign the patient to either:

• Group TA (n=30): Tumescent anesthesia alone
• Group TA+FNB (n=30): Tumescent anesthesia with ultrasound-guided femoral nerve block

Anesthesia and Procedure

Group TA Protocol:

Patients were positioned supine with mild knee flexion and hip external rotation. After sterile preparation, intradermal 1% lidocaine was administered for local anesthesia. Under ultrasound guidance, the incompetent GSV was punctured with an 18G needle, and a guidewire was advanced. An introducer sheath was placed, and the radiofrequency ablation (RFA) catheter was positioned 2.5-3 cm distal to the saphenofemoral junction. Tumescent anesthesia (25ml lidocaine with adrenaline diluted in 500ml normal saline) was injected under ultrasound guidance until a perivenular halo of 1cm was achieved. RFA was then performed until complete GSV ablation.

Group TA+FNB Protocol:

Similar positioning and preparation were used. A linear ultrasound transducer (5-12 MHz) identified the femoral nerve lateral to the common femoral artery. Using an in-plane technique, 10ml of 1% lidocaine was injected around the nerve with a 22G needle. After 10 minutes, sensory loss was confirmed. The same EVA procedure as Group TA was then performed.

Outcome Measures

Primary Outcome:

• Intraoperative pain assessed using VAS (0-10 scale) during TA infiltration and ablation

Secondary Outcomes:

• Procedure duration (from TA infiltration to completion of compression bandaging)
• Postoperative pain at 1, 2, 6, 12, and 24 hours using VAS
• Time to home readiness assessed by Modified PADSS Score (≥11 indicates readiness)
• Postoperative analgesic requirement (administered if VAS ≥3)
• Motor block assessed by Modified Bromage Score at 1 hour
• Complications (hematoma, nerve injury, skin injury)

Statistical Analysis

Data were analyzed using IBM SPSS Statistics version 23.0. Continuous variables were expressed as mean ± standard deviation (SD) and compared using independent t-tests or Mann-Whitney U tests based on normality. Categorical variables were presented as frequencies (percentages) and compared using chi-square or Fisher's exact tests. Repeated measures were analyzed using Friedman's test. A p-value <0.05 was considered statistically significant.

Demographic and Baseline Characteristics

Sixty patients completed the study, with 30 in each group. The mean age was 39.37 ± 12.15 years in Group TA and 42.90 ± 10.00 years in Group TA+FNB (p=0.224). Male predominance was observed in both groups (83.3% in TA vs. 86.7% in TA+FNB, p=1.000). No significant differences were found in age distribution, gender, or occupational risk factors between groups (Table 1).

Table 1: Demographic Characteristics of Study Participants

Primary and Secondary Outcomes

Intraoperative Pain: Group TA+FNB had significantly lower intraoperative VAS scores compared to Group TA (2.37 ± 0.49 vs. 3.30 ± 0.92, p<0.001). This difference persisted at 1 hour postoperatively (2.13 ± 0.43 vs. 2.50 ± 0.78, p=0.019), but no significant differences were observed at subsequent time points (Table 2).

Procedure Duration: The mean procedure duration was significantly longer in Group TA+FNB (38.97 ± 5.52 minutes) compared to Group TA (32.53 ± 4.09 minutes, p<0.001).

Postoperative Analgesic Requirements: Significantly fewer patients in Group TA+FNB required postoperative analgesics compared to Group TA (16.7% vs. 53.3%, p=0.003).

Time to Home Readiness and Complications: All patients in both groups achieved a Modified PADSS Score of 12 at 2 hours postoperatively, indicating readiness for discharge. No significant differences were observed in hospital stay duration or complication rates. All patients had a Modified Bromage Score of 0 at 1 hour, indicating no motor blockade. No hematomas, nerve injuries, or skin injuries occurred in either group.

Table 2: Pain Scores and Procedure Duration

Table 3: Postoperative Outcomes

This study demonstrates that combining ultrasound-guided femoral nerve block with tumescent anesthesia significantly improves analgesia during endovenous thermal ablation of varicose veins compared to tumescent anesthesia alone. The TA+FNB group experienced substantially lower intraoperative pain scores and reduced postoperative analgesic requirements, supporting our primary hypothesis. These findings align with previous research by Al Wahbi et al. [14], who reported VAS scores of 7.95 with TA alone versus 1.08 with TA+FNB, and Dzieciuchowicz et al. [15], who observed reduced pain with FNB during endovenous laser ablation.

The superior analgesia in the TA+FNB group can be attributed to the comprehensive sensory blockade provided by the femoral nerve, which innervates the medial thigh and leg where GSV ablation is performed [16]. By anesthetizing this region prior to TA infiltration, we effectively preempted the pain associated with multiple needle punctures and tumescent fluid injection. This approach addresses a significant limitation of TA alone, which requires numerous injections along the GSV course, often causing considerable discomfort despite local anesthetic use [17].

Interestingly, while the TA+FNB group had better pain control, the procedure duration was approximately 6 minutes longer than with TA alone. This increase is attributable to the additional time required to perform the FNB (approximately 8-10 minutes). However, this modest prolongation seems clinically acceptable given the substantial benefits in pain reduction and patient comfort. Similar findings were reported by Hanbeyoglu et al. [18], who noted longer procedure times with FNB but significantly improved pain scores during endovenous procedures.

The reduction in postoperative analgesic requirements in the TA+FNB group (16.7% vs. 53.3%) is clinically significant. This finding suggests that the analgesic benefits of FNB extend beyond the intraoperative period, likely due to the prolonged effect of local anesthetics used in nerve blocks compared to tumescent infiltration [19]. This reduction in analgesic use may decrease the risk of opioid-related side effects and improve overall patient satisfaction.

Notably, both groups achieved excellent discharge readiness scores at 2 hours postoperatively, with no complications observed. This indicates that both techniques are safe for outpatient settings. The absence of motor blockade in the TA+FNB group, as evidenced by all patients having a Modified Bromage Score of 0, is particularly important as it preserves mobility and facilitates early discharge. This contrasts with some studies that reported transient motor weakness following FNB [20], possibly due to differences in local anesthetic volume or concentration.

Our study has several strengths, including its prospective randomized design, standardized protocols, and comprehensive outcome assessment. However, limitations include the single-center setting and relatively small sample size. Additionally, the study was not blinded due to the nature of the interventions, which could introduce bias in pain assessment. Future multicenter trials with larger samples and blinded outcome assessment would further validate these findings.

The clinical implications of our results are significant. For patients undergoing EVA for varicose veins, TA combined with FNB offers a superior analgesic profile compared to TA alone, with minimal impact on safety or discharge readiness. This approach may improve patient acceptance of office-based procedures and enhance overall satisfaction with minimally invasive vein treatments [21].

This prospective randomized comparative study demonstrates that combining ultrasound-guided femoral nerve block with tumescent anesthesia significantly improves analgesia during endovenous thermal ablation of varicose veins compared to tumescent anesthesia alone. The TA+FNB approach resulted in substantially lower intraoperative pain scores and reduced postoperative analgesic requirements, despite a modest increase in procedure duration. Both techniques were safe with no complications observed, and all patients achieved discharge readiness within 2 hours. These findings support the use of femoral nerve block as a valuable adjunct to tumescent anesthesia for enhancing patient comfort during minimally invasive vein procedures.

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