1. Aetna considers placement of balloon-expandable venous stents with or without initial thrombolysis or surgical thrombectomy medically necessary for any of the following indications:
   • Budd-Chiari syndrome (thrombotic obstruction of major hepatic veins); or
   • Chronic iliac vein occlusions; or
   • Ilio-femoral thrombosis secondary to iliac compression syndrome (compression of the left iliac vein between the right iliac artery and the fifth lumbar vertebra); or
   • Post-operative venous narrowing due to repair of sinus venosus atrial septal defect (ASD); or
   • Pulmonary artery stenosis and/or hypoplasia in a child; or
   • Salvage of thrombosed or stenotic arterio-venous dialysis access grafts; or
   • Superior or inferior vena caval stenosis in a child or adult; or
   • Symptomatic pelvic venous spurs (May-Thurner syndrome) -- left deep venous thrombosis or post-thrombotic leg swelling; or
   • Venous obstruction of the superior or inferior limb of an atrial baffle after Mustard or Senning repair of transposition of the great arteries.

2. Aetna considers balloon-expandable venous stents experimental and investigational for all other indications because of insufficient evidence of effectiveness.

Endovascular balloon dilation has been proven to be effective in a great majority of patients with stenoses or occlusions of major veins.  It is performed to re-establish venous flow and relieve symptomatic venous obstructions secondary to benign disease, malignant disease, and/or radiotherapy and has been associated with little morbidity and mortality.  The addition of balloon-expandable stents to the armamentarium has increased the overall success rate in a variety of clinical scenarios.  Stents have been found to be particularly useful in dilatable venous lesions whose intrinsic elasticity results in vessel recoil after balloon dilation alone.

In children, there have been numerous reports of successful balloon dilation with stent placement of systemic venous stenoses, especially in patients who have post-operative narrowing due to repair of sinus venosus atrial septal defect (ASD) or Mustard or Senning operation.  Balloon-expandable stents for superior vena caval stenosis, occurring in patients with sclerosing mediastinitis due to malignancy or other causes, is recommended as a preferred alternative to surgery, as operative repair is difficult and somewhat unrewarding.  In contrast to the success observed with systemic venous obstruction, the limited experience with pulmonary vein stenosis dilation has been almost uniformly futile.  Even when some initial successes were reported, stenosis recurred in virtually every instance.

Balloon-expandable stents have also been used successfully to treat superior or inferior vena caval stenosis in children and adults.  Stenting appears to provide excellent short- and intermediate-term relief of such large venous obstructions, which may be associated with the presence of indwelling central venous lines or mediastinal malignancy, either before or after radiation therapy.  Superior vena cava syndrome, mainly associated with malignant tumors, is usually resistant to any therapy.  Although mechanical dilation of narrowed lumen is ideal for relief of symptoms, conventional balloon angioplasty has not been effective.  Surgical intervention is not a good choice in patients with advanced malignant tumors.  Recently developed expandable metallic stents have been adopted to the superior vena cava syndrome with good results.

Budd-Chiari syndrome (BCS) is an uncommon form of portal hypertension caused by obstruction of the hepatic venous outflow.  Primary BCS requires different therapies depending on the stage of the disease.  The fulminant or chronic forms with irreversible hepatic damage require definitive treatment, such as orthotopic liver transplantation.  For the acute or subacute forms, characterized by reversible hepatic injury, a porto-systemic shunt represents the most effective treatment.  The patients at poor hepatic risk can be treated by balloon-expandable stents.  In both cases preliminary caval stenting is necessary if the syndrome is complicated by significant obstruction of the inferior vena cava.

Iliac vein compression syndrome is a clinical condition that occurs as a result of compression of the left iliac vein between the right iliac artery and the fifth lumbar vertebra.  Venous hypertension develops and patients usually have marked edema of the left leg, sometimes leading to recurrent episodes of left leg cellulitis.  Besides surgical repair, stenting has been shown to restore and maintain venous flow through the compressed area, relieving the leg edema.