Adding a mechanical suction technique to local thrombolysis to break up and remove blood clots reduced postthrombotic syndrome (PTS) after deep vein thrombosis (DVT) without causing increased complications, according to a small retrospective study .
Dr. Chun-Yang Huang of the National Yang Ming University (Taipei, Taiwan) and colleagues examined patients diagnosed with acute proximal lower limb DVT. Patients received either thrombolysis alone via a catheter-directed thrombolysis (CDT), or percutaneous mechanical thrombectomy (PMT) by a combination of pharmacologic thrombolysis and suction; both techniques were accompanied by systemic anticoagulation. Though both treatment groups fared well during treatment and for the 12-month follow-up period, the PMT group had a significantly lower incidence of PTS 1 year after treatment (Ann. Vascular Surg. 2015. doi: 10.1016/j.avsg.2015.01.014 ).
For those with DVT, parenteral anticoagulation prevents propagation of the clot and minimizes risk of pulmonary embolism (PE); however, anticoagulation does not accelerate dissolution of the existing clot. According to study authors, 30%-40% of those with proximal leg DVTs will go on to develop PTS, with the prolonged distal venous stasis from an undisturbed clot causing loss of valvular competence and resultant chronic venous insufficiency. PTS can involve leg swelling, discomfort, skin changes, and ulceration, with significant impact on quality of life and health care costs.
Techniques such as CDT and PMT can increase the rate of clot dissolution, thus restoring patency sooner and minimizing risk for PTS. However, these methods also can carry increased risk of bleeding and infection, considerations that must be balanced against potential benefit.
Investigators reviewed records for 39 patients who were diagnosed with ultrasound- or CT-confirmed acute proximal lower limb DVT and received either CDT or PMT during the period from November 2010 to November 2013. Patients were not randomized to treatment arms but were assigned using clinical judgment and patient preference. During the 12-month follow-up, three participants died of malignancy and two were lost to follow-up. Analysis was completed for the remaining 34 patients.
Overall, patient characteristics did not differ significantly between groups, with mean ages of 62.75 for the PMT group (n = 16) and 64.17 for the CDT group (n = 18). In all, 13/34 participants were female. Patients in both treatment groups fared well, with no 30-day mortality, and no episodes of major bleeding, PE, or renal failure. Ten patients in the PMT group and six in the CDT group required stenting of the common iliac vein to maintain patency, a nonsignificant difference. Just one participant in the CDE group experienced a minor bleeding event.
Turning to outcomes, study authors assessed postprocedure patency, finding improved patency for both procedures (P less than .001 for both, compared with preoperation patency scores), with no significant difference between the two groups post procedure. Thrombus scores were also significantly better for both treatment arms post procedure (P less than .001). Clot burden tended to improve more rapidly over the 12-month follow-up period for the PMT group, though the difference between groups was just short of statistically significant.
At 12 months, though the amount of venous reflux did not differ significantly between groups, those who had received PMT had significantly fewer signs and symptoms of PTS. This assessment used the Villalta scale, a standardized assessment and scoring system for PTS, where higher numbers indicate worse PTS. The PMT group’s Villalta score was 2.06 +/–2.95, compared with 5.06 +/–4.07 for the CDT group (P = .030).
Study limitations included the small study size, retrospective study design, and lack of randomization. Acknowledging these limitations, Dr. Huang and coauthors called for larger, multicenter, randomized controlled studies of PMT. The personal and economic costs of PTS, they argue, warrant exploring whether PMT may help minimize total thrombolysis dose, reduce hospital stays, and decrease costs while minimizing the risks of chronic venous insufficiency post DVT.
Dr. Huang and coauthors reported no conflicts of interest.
