5 Safety

5 Safety

This section describes safety outcomes from the published literature that the committee considered as part of the evidence about this procedure. For more detailed information on the evidence, see the interventional procedure overview.

5.1 In a randomised controlled trial (RCT) of 117 patients, no patients treated by mechanochemical ablation and 1 patient treated by radiofrequency ablation had deep vein thrombosis. In a case series of 449 patients, 1 patient had deep vein thrombosis, diagnosed in the popliteal vein 3 weeks after treatment. The patient was treated with coumarins for 3 months and, at 6‑month follow‑up, the popliteal vein was no longer occluded. In the same study, pulmonary embolism was reported in 2 patients, 1 week postoperatively in 1 patient and 1 month postoperatively in the other. This patient also had a deep vein thrombosis in the popliteal and femoral vein of the treated limb. Both patients were admitted overnight and treated with coumarins. Neither patient had any sequelae.

5.2 Sural nerve injury resulting in transient hyperaesthesia was reported in 1 patient in the case series of 449 patients. The patient already had sensory sural neuropathy after previous saphenopopliteal junction ligation, which was aggravated by the mechanochemical ablation.

5.3 Thrombophlebitis of the treated limb was reported in 2% (12/558) of limbs in the case series of 449 patients. Thrombophlebitis was reported in 0% (0/34) of patients treated by mechanochemical ablation and in 6% (2/34) of patients treated by radiofrequency ablation in a non‑randomised comparative study of 68 patients (p=0.49). Thrombophlebitis was reported in 0% (0/60) of patients treated by mechanochemical ablation and in 3% (2/59) of patients treated by radiofrequency ablation in the RCT of 117 patients. Superficial thrombophlebitis was reported in 3% of patients (absolute numbers not reported) and 13% (10/73) of legs in 2 case series of 92 patients and 63 patients respectively. Transient superficial thrombophlebitis of the treated vein was reported in 14% of patients (absolute numbers not reported) in a case series of 50 patients. Thrombophlebitis was reported in 10% of patients (absolute numbers not reported) in a case series of 126 patients. Pain and erythema were reported in 1% (6/558) of limbs in the case series of 449 patients. Hardening and pain at the injection site was reported in 18% (13/73) of legs in the case series of 63 patients. Induration was reported in 12% (4/34) of patients treated by mechanochemical ablation and in 24% (8/34) of patients treated by radiofrequency ablation in the non‑randomised comparative study of 68 patients (p=0.20). Induration along the course of the treated vein was reported in 12% of patients (absolute numbers not reported) in the case series of 92 patients.

5.4 Abscess at the puncture site was reported in 1 patient in the case series of 449 patients. A superficial wound infection was reported in 1 patient treated by mechanochemical ablation in a non‑randomised comparative study of 147 patients.

5.5 Haematoma at the puncture site was reported in 1 patient in the case series of 449 patients. Haematoma was reported in 6% (2/34) of patients treated by mechanochemical ablation and in 12% (4/34) of patients treated by radiofrequency ablation in the non‑randomised comparative study of 68 patients (p=0.67). Localised haematoma was reported in 9% of patients (absolute numbers not reported) in the case series of 92 patients. Localised ecchymosis was reported in 12% of patients (absolute numbers not reported) and 8% (6/73) of legs in the 2 case series of 50 and 63 patients respectively. Ecchymosis was reported in 9% of patients (absolute numbers not reported) and haematoma in 1% of patients (absolute numbers not reported) in the case series of 126 patients.

5.6 Hyperpigmentation was reported in 9% (3/34) of patients treated by mechanochemical ablation and in 9% (3/34) of patients treated by radiofrequency ablation in the non‑randomised comparative study of 68 patients. Mild hyperpigmentation at the puncture site was reported in 5% of patients (absolute numbers not reported) in the case series of 92 patients.

5.7 Retrograde inversion stripping of a small saphenous vein was reported in 1 patient in a case report. During the ablation procedure, the catheter got stuck and the motor was shut off. The catheter was pulled out and the entire small saphenous vein was also extracted, having been inversion stripped. The tip of the catheter was found to be fixed to a small, calcified tributary. The patient was asymptomatic and pain free at the 6‑week and 6‑month follow‑up. There was no recurrence, no sign of revascularisation and no neurological compromise.

5.8 In addition to safety outcomes reported in the literature, specialist advisers are asked about anecdotal adverse events (events which they have heard about) and about theoretical adverse events (events which they think might possibly occur, even if they have never done so). For this procedure, specialist advisers did not identify any additional anecdotal adverse events. They considered that the following were theoretical adverse events: vein perforation, migraine, visual disturbance and stroke.