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Endovenous Thermal Ablation Failure Explained


 

Endovenous thermal ablations with heat have revolutionized the treatment of patients with chronic venous disease. Both radiofrequency and laser ablations have been equally effective in causing early occlusion of the saphenous vein in more than 90% of patients in most studies, according to Dr. Peter Gloviczki.

Dr. Peter Gloviczki

The main reasons for anatomical failure of endothermal saphenous ablations are persistent patency of the vein after treatment and recanalization of the vein after primary occlusion. Reflux through saphenous tributaries and accessory saphenous veins is another cause of ablation failure. This occurs despite persistent occlusion of the great saphenous vein since the strategy of laser and radiofrequency (RF) treatment is saphenous ablation distal to groin tributaries, a method that corresponds to "low" ligation using a traditional open surgical technique, Dr. Gloviczki said at the Veith symposium on vascular medicine, which was sponsored by the Cleveland Clinic.

The development of recurrent varicose veins, deterioration of quality of life, and worsening of the patient’s VCSS (Venous Clinical Severity Scores) after the procedure are considered clinical failures. Any ablation procedure could also be considered a failure if there is a high risk of complications and if the cost is excessive, said Dr. Gloviczki, the Joe M. and Ruth Roberts Professor of Surgery at the Gonda Vascular Center at the Mayo Clinic in Rochester, Minn.

The common theme for anatomical failure is saphenous recanalization in 5%-26% of cases, which occurs after a very high rate of immediate early occlusion (reaching greater than 95% for the latest-generation laser and RF ablation). Anatomical failure, however, does not translate into clinical failure in most patients; more than three-fourths of those with recanalized saphenous veins remain asymptomatic at 1-2 years after intervention.

To illustrate this, Dr. Gloviczki discussed an important study of 185 limbs that grouped failures into the following three types:

Type 1 (nonocclusion). The treated vein failed to occlude initially and never occluded during follow-up (12%).

Type 2 (recanalization). The vein occluded after treatment but later recanalized partly or completely (70%).

Type 3 (groin reflux). The vein trunk occluded, but reflux was detected at the groin region, often involving an accessory vein (18%).

Most patients had symptomatic improvement despite anatomical failure, and 70%-80% of these "failed" patients remained asymptomatic, compared with 85%-94% of those with anatomical success. Varicose vein recurrence, however, was more frequent with type 2 and type 3 failures. The study investigators found that with the first-generation RF device, catheter pull-back speed and body mass index were the two risk factors associated with anatomical failures, Dr. Gloviczki said in an interview.

In Europe, steam has been used increasingly for thermal ablation, but whether this is more effective than RF and laser ablation remains to be seen, he stated.

Whatever the technique, endovenous thermal ablations are here to stay and clinical failure rates in the short- and midterms are comparable with those observed after open surgical treatment, he said. "So far, there is no convincing evidence that, of the currently used latest generation endothermal ablation techniques, one is better than the other or that any of them has a different failure rate than the traditional open surgery with high ligation and stripping," he added.

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