Acute deep vein thrombosis (DVT) affects nearly 1 million patients in the US annually, with up to 60% of these patients developing some degree of post-thrombotic syndrome (PTS). Although only 5–10% of patients with post-thrombotic syndrome will develop venous ulcers, the quality of life limitations brought on by chronic DVT and PTS can be quite debilitating. In this population, standard of care therapy with therapeutic anticoagulation, elastic compression stocking (ECS) and early ambulation is simply not enough. What is known is that the more central the venous occlusion, the higher the probability of developing PTS. In addition, the higher the ambulatory venous pressures, the more severe the sequelae of PTS may be.

The goal in treating patients suffering from chronic deep vein thrombosis is to reduce the severity of PTS, prevent
progression of PTS, and improve their quality of life overall. An important factor in defining patient expectations is making the appropriate diagnosis and identifying the extent of occlusion including the most central aspect. To obtain maximum benefit of pre-invasive therapy, it is imperative that certain measures are met, which include maintenance of a therapeutic level of anticoagulation as well as proper usage of compression stockings while encouraging activity and exercise.

Only after maximized conservative therapies show no clinical improvement, one might then consider invasive treatment. The goal in treating chronic occlusive DVT and PTS is to relieve the venous obstruction by restoring flow, thus decreasing the venous pressures and, ultimately, the severity of PTS.

Patient evaluation

Initial evaluation of the patient presenting with a history of chronic DVT and PTS includes obtaining the full medical history, including date of symptom onset as well as reviewing the patients imaging and lab work. One can also determine if a full hypercoagulable workup is indicated if not yet performed. Risk factors should be identified and contraindications for interventional therapy should be excluded. A full history and physical exam should include evaluation for severity of PTS using standard scoring systems including CEAP classification, Villalta score, or Venous Clinical Severity Score (VCSS). Additionally, a quality of life questionnaire (such as VEINES) should be completed pre- and post-procedure to establish the baseline function and help assess the benefit obtained from the intervention. The physical exam should include not only observations of external changes and asymmetry in the extremity, but also measurements of both the normal and affected limb at defined reproducible locations. If upon exam and review of available imaging, there are concerns for central venous occlusion, consider CT or MR venography to identify the central extent of the occlusion and better assess the central venous anatomy. This will also aid in determining the access site once intervention is agreed upon.

Ensuring standard of care conservative therapy has been achieved is crucial in obviating unnecessary risks and placing the patient at potential harm by intervening prematurely. The benefits of maximizing conservative therapy include:

• Anticoagulation: enhancing flow out of occluded pathways via collaterals and diseased but patent segments
• Compression: External compression helps augment venous flow, neutralize increased venous pressures while helping to preventing soft tissue-edema, as well as giving resistance to reflux in diseased but patent veins.
• Exercise: While patients with chronic DVT may suffer from poor quality of life and significant lifestyle limitations, increasing their level of activity and exercise, albeit slow and difficult, can aid in the development of collateral pathways and improved flow into either alternative deep vein pathways or superficial veins, which can lead to improved
• PTS symptoms. This can be likened to an exercise program in a patient with peripheral arterial disease.

Preprocedure Planning

Once the patient and interventionalist agree that conservative therapy has failed to give adequate benefit or improvement, endovascular treatment can be considered. Standard preprocedure laboratory studies should be obtained. I suggest performing the procedure once low molecular weight heparin has been initiated. If the patient is currently on warfarin, the patient is transitioned to enoxaparin immediately prior to the procedure. Therapeutic anticoagulation is continued throughout the procedure and for three months post-procedure prior to transitioning them back to Coumadin. An alternative regimen is to consider switching to rivaroxaban once treatment is completed. It has been my personal experience that post-procedure patency is enhanced with the use of factor Xa inhibitors. Low molecular weight heparins also reduce the need for weekly drug draws as well as the variability that can be seen with Coumadin. Performing intervention on patients already on oral Xa inhibitors has not yet been done.

Although there is no level one data in support of such intervention, chronic DVT recanalization has been reported to be safe while effectively achieved.6 This is best accomplished by reestablishing both inflow as well as outflow through the occluded venous segments. Preprocedural imaging and identifying the extent of occlusive disease will facilitate access site determination that will best achieve inflow into the occluded segment. If, for example, the ipsilateral popliteal and upper tibial veins are occluded, one might consider either a jugular, low tibial or contralateral femoral vein approach to allow for intervention of both the popliteal and tibial veins in an effort to improve calf outflow and popliteal inflow. Establishing flow throughout the treated venous segments is crucial in maintaining long-term patency.

Procedure

Procedural and technical details used in performing these procedures will not be discussed here, but can be seen in detail by referencing either the Endovascular Today, (July 2012 issue-7) or online at www.Medscape.com.

Post-Procedure Care

Once treatment has been completed, anticoagulation is continued without interruption, with instructions to use continuous pneumatic compression boots (PCBs) while at bed rest. Ambulation is encouraged as soon as possible. Patients are discharged with prescriptions for elastic compression stockings and anticoagulant drug of choice. It is my current practice to discharge patients on twice daily, weight-based enoxaparin (1 mg/kg bid) for one month, now transitioning to oral Xa inhibitor (Rivaroxaban, 20 mg daily). Furthermore, patients are strongly encouraged to initiate an exercise/ambulation program as early as 72 hours post procedure. Patients are seen in follow up with a venous Doppler exam at 1, 3, 6, 12, 18 and 24 months and annually thereafter. Color Doppler studies must be reviewed and carefully monitored to document patency and evaluate for luminal flow. Chronic venous changes will often be misread as persistent DVT rather than flow restored in the previously occluded segment. Wall thickening is also an expected finding with the desired finding being that of wall-to-wall color filling the lumen. Because these previously occluded segments are permanently damaged, even when flow is restored, the risk of venous insufficiency is expected. Therefore, the use of elastic compression stockings is recommended for an indefinite period. Quality of life questionnaires, as well as remeasuring the Villalta score at a minimum, is suggested at each office visit. Currently, I keep patients on anticoagulation for two years, at which point, if free from rethrombosis, they will be placed on aspirin indefinitely.

Summary

Deep vein thrombosis and its most common complication, post-thrombotic syndrome, can be devastating with significant debilitating outcomes. Management of this disorder entails maximizing conservative therapies prior to engaging in endovascular treatment. Recanalization of chronic occlusive DVT can safely and effectively be undertaken with significant improvement obtained in postthrombotic symptoms and Villalta scores as well as qualityof- life measures. Finally, this is good news for those suffering from chronic DVT and PTS—that there is hope for these patients with good news the possibility of restoring flow and relieving them from their debilitating disorder.