Abstract
Objectives:
Tumescent local anaesthesia via multiple injections in the perivenous space leads to intraoperative and postoperative pain during endovenous laser ablation (EVLA). We considered whether the application of topical local anaesthesia reduces pain caused by these injections.
Methods:
Eligible patients undergoing local anaesthetic EVLA were recruited and randomized to either application of topical local anaesthesia or water-based gel (placebo) to the inner thigh over the marked great saphenous vein. Varicose vein severity was classified using the American venous forum clinical etiological anatomical pathological (CEAP) classification score for chronic venous disorders and the Aberdeen varicose vein questionnaire (AVVQ) score. Visual analogue pain scores attributable to the varicose veins or tumescent injections were recorded before the procedure, immediately postprocedure and prior to discharge. Secondary outcome measures were extra analgesia requirement during or immediately postoperatively. Analysis was performed using the unpaired Student’s t test and Wilcoxon signed-rank test.
Results:
A total of 52 patients underwent the procedure. Eight patients were excluded from analysis due to failure to complete the procedure or incomplete data. In the remaining 44 patients (24 local anaesthesia, 20 placebo), no statistical difference was noted in age, gender distribution or the severity of varicose veins assessed preoperatively by the clinician (CEAP classification score, median = 2 in both groups) and patient (AVVQ, mean placebo = 21.59, local anaesthesia = 17.53, p = 0.264) between the two groups. There was no statistical difference in pain scores between the placebo and topical local anaesthetic group at baseline (23.0 versus 20.44, p = 0.57), immediately postoperatively (23.35 versus. 19.75, p = 0.44) or predischarge (20.9 versus 13.75, p = 0.68).
Conclusions:
Topical local anaesthesia is of no benefit in EVLA of varicose vein to reduce patient experience of perioperative pain.
Introduction
Varicose veins affecting the lower limbs are a common medical condition affecting up to approximately 27% of western adults [Beebe-Dimmer et al. 2003]. Over the last decade minimally invasive endoluminal techniques such as endovenous laser ablation (EVLA) pioneered by Min and Navarro [Rautio et al. 2002; Navarro et al. 2001], have gained widespread popularity. This is attributed to patient preferences due to reduced perioperative pain, morbidity and faster recovery compared with traditional surgery [Rasmussen et al. 2007]. Also, the procedure may be performed in an office or day-case setting under tumescent anaesthesia [Rasmussen et al. 2007; Van den Bos et al. 2009]. It has been demonstrated to be both safe and effective for the management of varicose veins in a number of clinical trials and meta-analyses, and is endorsed by the National Institute for Health and Care Excellence (NICE) [NICE, 2004; Rasmussen et al. 2007; Van den Bos et al. 2009; Darwood et al. 2008; Luebke and Brunkwall, 2008; Kalteis et al. 2008; Carradice et al. 2011]. The perivenous tumescence has the function of protecting perivenous structures such as nerves and skin from laser burns as well as increasing contact of the endoluminal surface and laser probe. However, this requires multiple injections along the length of the great saphenous vein (GSV). In the experience of the authors and the literature [Firouznia et al. 2013], these numerous injections, which are noxious stimuli to the skin, contribute to the perception of pain in many patients during the procedure. It was therefore hypothesized that the administration of a topical local anaesthesia to the skin prior to these injections may reduce intraoperative pain and perioperative analgesia requirement.
Patients and methods
Patients and inclusion criteria/suitability for EVLA
Ethical approval for the study was obtained from the East of England branch of the National Research Ethics Service. Consecutive adult patients with primary symptomatic varicose veins due to proven sapheno–femoral junction and GSV reflux on duplex ultrasound amenable to endovenous laser therapy were invited to participate in the trial. Exclusion criteria included recurrent varicose veins, reflux in other axial or duplicate veins, the requirement for general anaesthesia (patient preference/requirement) or patients having concurrent procedures at the time of EVLA such as avulsions. All patients received written and verbal information regarding the study according to the Helsinki declaration and written consent was obtained. Anonymized data related to the study can be provided upon request by contacting the corresponding author.
Study design
Participating patients were randomized through random number tables by an independent researcher not involved in the data collection or analysis to either a placebo (topical water-based gel) or intervention (topical local anaesthesia gel; EMLATM cream 5%, AstraZeneca, Luton, UK) group. Patients underwent marking of the GSV in the thigh before the gels were applied from masked containers 20 min prior to the procedure. Thus the patient, surgeon and researcher collecting data were blinded to the treatment allocation.
Power calculations were based on an estimated mean postoperative visual analogue pain score (VAS) of 34 mm (standard deviation 20 mm) from the largest available series (n = 70) at the time of the study design [Darwood et al. 2008]. Todd and colleagues’ study demonstrated the minimum clinically significant difference in VAS of pain was 13 mm and has subsequently been further validated [Todd et al. 1996; Gallagher et al. 2001]. Thus, for 80% power and a two-sided significance of 5%, the estimated minimum sample size was 19 procedures per group.
Standard laser technique
All endovenous laser procedures were performed by one of two surgeons on a day-surgery basis under local tumescent anaesthesia in an operating theatre using an 810 nm laser source (Endo Venous Laser Treatment [EVLTTM], Diomed, Cambridge, UK). Ultrasound-guided cannulation of the GSV just above or below the knee was performed and a 5 F catheter introduced using the Seldinger technique. The patient was placed in the Trendelenburg position. Ultrasound was used to guide the manual perivenous infiltration of 500 ml normal saline mixed with 40 ml 1% lignocaine with 1:200,000 adrenaline solution via multiple (approximately five to seven) injections in the inner thigh in the distal to proximal direction. An 810 nm laser fibre was introduced via the catheter and thermal ablation of the endoluminal surface achieved with continual withdrawal of the laser fibre and catheter set at a continuous power delivery of 14 W. Following the procedure compression with bandages and later class 2 support stockings was applied to the treated limb for 2 weeks.
Data collection and analysis
Developed in 1994 by the American Venous Forum, the Clinical Etiology Anatomical Pathological (CEAP) classification for chronic venous disease [Eklöf et al. 2004] is widely used to assess severity by clinicians. Meanwhile, the Aberdeen Varicose Vein Questionnaire (AVVQ) [Garratt et al. 1993], is a validated disease-specific measure of quality of life from the patients’ perspective. Both tools were used to assess the severity of varicose veins preoperatively. Pain scores attributable to the varicose veins and postoperatively specifically due to the tumescent injections were documented using a VAS along a 100 mm bar preoperatively (baseline), immediately postoperatively in the operating theatre and prior to discharge (within 3 h of procedure). In addition, the most potent analgesia (paracetamol, nonsteroidal anti-inflammatory or opioids) required at each of these time points was recorded. Data analysis of parametric data was performed using unpaired Student’s t test and Wilcoxon signed-rank test for nonparametric data to assess for statistically significant differences set at the 5% level.
Results
Over the 2-year study period 52 patients were recruited to the study. In five patients the data were incomplete and in three patients the procedure was abandoned due to difficulty in cannulation. In the remaining 44 patients (24 local anaesthesia, 20 placebo), there was no statistical difference in mean ages or gender distribution (Table 1). The severity of varicose veins assessed preoperatively by the clinician (CEAP classification score, median = 2 in both groups) and patient (AVVQ, mean placebo = 21.59, local anaesthesia = 17.93) were similar as were baseline pain scores (23.0 versus 20.44).
Comparison of patient baseline characteristics.
No statistical difference of the mean AVVQ between placebo and local anaesthesia groups, p = 0.264.
Fisher’s exact test. AVVQ, Aberdeen varicose vein questionnaire; CEAP, clinical etiological anatomical pathological classification score for chronic venous disorders.
Pain scores in both groups improved with time postoperatively. There was no statistically significant difference in pain experience from the tumescent injections between the placebo and topical local anaesthetic group as reflected in their pain scores at each time point (Table 2). Analgesia requirements immediately postoperatively and predischarge were comparable in both groups (Table 2). Improvement in AVVQ was noted in both placebo and treatment groups and no significant differences were noted between the groups when compared directly, which demonstrated a similar cohort of patients in each group.
Mean pain scores, analgesia requirements and Aberdeen varicose vein questionnaire score for placebo and local anaesthetic groups.
Discussion
Endovenous techniques for the management of varicose veins have become increasingly popular and thus refinement and optimization of the technique is essential. EVLA is frequently performed under tumescent local anaesthesia only and it has been postulated that the multiple injections required to provide this are a significant source of intraoperative pain. This pilot double-blind randomized control trial demonstrated that although lower mean pain scores were recorded perioperatively in patients who had topical local anaesthesia gel applied to the thigh prior to laser treatment, this was not statistically significant. It is possible that although the topical local anaesthesia ameliorates the pain of the tumescent needle passing through the skin as noted by previous studies [Biro et al. 1997], it does not have any effect on the discomfort caused by the pressure of the tumescent fluid being forced into the perivenous space or the discomfort from the laser procedure itself. It is also postulated that the tumescent anaesthesia may itself have greater analgesic properties in both groups once it has had the opportunity to take effect, accounting for the lack of difference in pain experience between the two groups. Other recognized methods of providing analgesia during the endovenous laser treatment for varicose veins include general anaesthesia and inhaled equimolar nitrous oxide/oxygen [Meier et al. 2015].
Perioperative pain scores and analgesia use noted were similar to VAS scores from other EVLA studies [Gunes et al. 2015; Elderman et al. 2014], demonstrating that the clinical technique and pain assessment methods are comparable with other studies. The distal to proximal approach (rather than proximal to distal) of injecting perivenous tumescence was used, which has been demonstrated to be optimal for the patient in terms of pain from tumescent injections and number of puncture sites required [Kutas et al. 2015]. The findings that the AVVQ scores were reduced in both groups following treatment with EVLA is in concordance with other trials [Rasmussen et al. 2007; Van den Bos et al. 2009; Rautio, 2002].
This study was limited by its relatively small sample size. This is a pilot study and the calculation was based on the assumption of a 30% difference in pain score. A larger sample size may have detected a smaller difference in pain scores; however, such a difference may be too small to justify routine use of topical anaesthesia.
Conclusion
There is no benefit in using topical local anaesthesia for EVLA of varicose veins to reduce patient experience of perioperative pain.
Footnotes
Authors’ note
The data has been presented orally at the Association of Surgeons of Great Britain and Ireland International Surgical Congress, ‘Expertise & Excellence’, Liverpool, UK, 2012.
Funding
This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Conflict of interest statement
The authors declare that there is no conflict of interest.