Arterial false aneurysm in the groin following endovenous laser ablation

Introduction

Endovenous laser ablation (EVLA) is a well-established minimally invasive percutaneous catheter-based procedure for treating truncal varicose veins, which is now favoured above stripping (NICE 2013, CG168). Heating of the vein wall by laser energy causes thermal damage, which leads to fibrosis and ablation of the vein. EVLA is considered a very safe procedure, with the most common consequences of treatment being pain and ecchymosis. ¹ A review of literature and cases of EVLA-induced complications found that only <1% of EVLA cases are associated with serious complications such as nerve injury, deep vein thrombosis (DVT), embolism and skin burns. ¹ The case described is of a false aneurysm following EVLA.

Case report

A 45-year-old woman presented with extensive bilateral varicose veins and thread veins, which had worsened over the previous two years. Following duplex scanning, bilateral EVLA of the great saphenous vein, left anterior accessory saphenous vein and right small saphenous vein was performed. She had a history of DVT and was heterozygous for factor V Leiden. Therefore, it was decided to give a subcutaneous low-molecular-weight heparin, and on patient weight, 4000 IU of dalteparin sodium (Fragmin, Eisai Inc.) was given at the end of the procedure as DVT prophylaxis.

EVLA was performed using standard Seldinger insertion under ultrasound guidance (Biolitec ELVeS Radial kit). Duplex ultrasound-guided tumescent anaesthesia (2% lidocaine/adrenaline 1:200,000 (20 ml), sodium chloride 0.9% (480 ml) and sodium bicarbonate 8.4% (5 ml)) was placed around each vein using a Klein pump and a standard 21 G (green) needle. A target linear endovenous energy density (LEED) of 70 J/cm was planned (10 watts, pull-back 7 s/cm). The measured LEED in the great saphenous vein was 64.7 J/cm. Vein closure was confirmed by duplex scanning, and heparin was administered as planned.

Following the procedure, the patient was discharged fully mobile and well. On the way home, the patient had sudden and severe pain in the right groin with swelling. On immediate return to the clinic, 3 h post EVLA, ultrasound confirmed a false femoral aneurysm (9 × 5 × 4.5 cm) (Figure 1). An arterial jet was identified from a branch of the inferior epigastric artery. OPEN IN VIEWER

Initial compression by ultrasound transducer was not successful. Intravenous protamine was administered in 10 mg aliquots by slow intravenous infusion (5 mg/min), in line with the British National Formulary (BNF) 63 (March 2012), to reverse the heparin. After 40 mg (to reverse 4000 IU dalteparin sodium) of protamine was administered, bleeding continued and so a decision was made to give further protamine with compression. After administering two more 10 mg aliquots with ultrasound transducer compression and then manual compression, the bleeding was successfully stopped. We are aware that the dose of protamine administered was above that recommended by the BNF. The protamine was being titrated against bleeding, and it was decided that this dose was necessary for a successful outcome. The false aneurysm itself was left to re-absorb which it has done over 12 months.

Discussion

False aneurysm after EVLA is a very rare complication. We do not think that damage to the branch of the inferior epigastric artery was caused by the laser. The most probable explanation for the development of the false aneurysm is direct trauma to the artery by the needle used to inject the tumescent anaesthesia. Formation of false aneurysms has been reported following injection of local anaesthesia in other procedures.^2,3

Despite EVLA being such a widespread operation, the fact this complication is rare suggests that the mechanism is not easily repeated. Despite ultrasound control, the tip of the tumescent needle is not always visualised in the ultrasound beam. It is likely that in this case, the needle ‘pierced’ the arterial wall rather than direct puncturing leading to a hole less likely to stop bleeding with simple protamine – a situation worsened by subcutaneous heparin.

Although tumescent anaesthesia avoids the complications associated with spinal and general anaesthesia, problems including nerve damage and ecchymosis can arise and administration can be painful. ⁴ Newer techniques for the treatment of varicose veins, MechanoChemical Endovenous Ablation (MOCA™) and cyanoacrylate glue (VenaSeal™), which do not involve tumescent anaesthesia, would avoid complications such as these.^4,5