Residual rates of reflux and obstruction and their correlation to post-thrombotic syndrome in a randomized study on catheter-directed thrombolysis for deep vein thrombosis

Patency and reflux in relation to postthrombotic syndrome: a subanalysis of the Ultrasound-Accelerated Catheter-Directed Thrombolysis Versus Anticoagulation for the Prevention of Post-Thrombotic Syndrome trial

BACKGROUND

Adjunctive catheter-directed thrombolysis shows variable efficacy in preventing postthrombotic syndrome (PTS), despite restored patency.

OBJECTIVES

This Ultrasound-Accelerated Catheter-Directed Thrombolysis Versus Anticoagulation for the Prevention of Post-Thrombotic Syndrome (CAVA) trial subanalysis investigated the effect of ultrasound-accelerated catheter-directed thrombolysis (UACDT) on patency, reflux, and their relevance in PTS development.

METHODS

This multicenter, randomized, single-blind trial enrolled patients (aged 18-85 years) with a first iliofemoral deep vein thrombosis and symptom duration ≤14 days. Patency and reflux were assessed by duplex ultrasound at 12 months (T12) and long-term (LT) follow-up (median, 39.5 months; IQR, 24.0-63.0 months). PTS was diagnosed using the Villalta score.

RESULTS

UACDT significantly improved patency in all vein segments at T12 (60.3% UACDT vs 25.9% standard treatment [ST]; P = .002) and LT (45.2% UACDT vs 11.9% ST; P < .001). Popliteal patency, however, was similar between groups (87.9% UACDT vs 83.3% ST; P = .487). Reflux was similar between groups at T12 and LT; only popliteal reflux was significantly reduced in the UACDT group at LT (22.6% UACDT vs 44.8% ST; P = .010). Absent iliac patency at T12 was associated with increased PTS risk in the ST group only (odds ratio [OR], 10.84; 95% CI, 1.93-60.78; P = .007). In the UACDT group, popliteal reflux at T12 was associated with moderate-to-severe PTS at T12 (OR, 4.88; 95% CI, 1.10-21.57; P = .041) and LT (OR, 5.83; 95% CI, 1.44-23.63; P = .009). Combined popliteal reflux and absent iliac patency significantly amplified PTS risk (OR, 10.79; 95% CI, 2.41-48.42; P < .001).

CONCLUSION

UACDT improved patency and reduced popliteal reflux. Iliac patency and popliteal reflux are independently associated with moderate-to-severe PTS and contribute synergistically to its development. However, a proportion of moderate-to-severe PTS cases lacks an evident underlying cause.

Delphi Consensus on Reporting Standards in Clinical Studies for Endovascular Treatment of Acute Iliofemoral Venous Thrombosis and Chronic Iliofemoral Venous Obstruction

Acute iliofemoral deep vein thrombosis and chronic iliofemoral venous obstruction cause substantial patient harm and are increasingly managed with endovascular venous interventions, including percutaneous mechanical thrombectomy and stent placement. However, studies of these treatment elements have not been designed and reported with sufficient rigor to support confident conclusions about their clinical utility. In this project, the Trustworthy consensus-based statement approach was utilized to develop, via a structured process, consensus-based statements to guide future investigators of venous interventions. Thirty statements were drafted to encompass major topics relevant to venous study description and design, safety outcome assessment, efficacy outcome assessment, and topics specific to evaluating percutaneous venous thrombectomy and stent placement. Using modified Delphi techniques for consensus achievement, a panel of physician experts in vascular disease voted on the statements and succeeded in reaching the predefined threshold of >80% consensus (agreement or strong agreement) on all 30 statements. It is hoped that the guidance from these statements will improve standardization, objectivity, and patient-centered relevance in the reporting of clinical outcomes of endovascular interventions for acute iliofemoral deep venous thrombosis and chronic iliofemoral venous obstruction in clinical studies and thereby enhance venous patient care.

Society of Interventional Radiology Position Statement on the Endovascular Management of Acute Iliofemoral Deep Vein Thrombosis

PURPOSE

To establish the updated position of the Society of Interventional Radiology (SIR) on the endovascular management of acute iliofemoral deep vein thrombosis (DVT).

MATERIALS AND METHODS

A multidisciplinary writing group with expertise in treating venous diseases was convened by SIR. A comprehensive literature search was conducted to identify studies on the topic of interest. Recommendations were drafted and graded according to the updated SIR evidence grading system. A modified Delphi technique was used to achieve consensus agreement on the recommendation statements.

RESULTS

A total of 84 studies, including randomized trials, systematic reviews and meta-analyses, prospective single-arm studies, and retrospective studies were identified and included in the review. The expert writing group developed 17 recommendations that pertain to the care of patients with acute iliofemoral DVT with the use of endovascular venous interventions.

CONCLUSIONS

SIR considers endovascular thrombus removal to be an acceptable treatment option in selected patients with acute iliofemoral DVT. Careful individualized risk assessment, high-quality general DVT care, and close monitoring during and after procedures should be provided.

Improvement following restoration of inline flow argues against comprehensive thrombus removal strategies and for selective stenting in acute symptomatic iliofemoral venous thrombosis

OBJECTIVE

Randomized trials have demonstrated the benefit of thrombus removal strategies in iliofemoral deep venous thrombosis (IFDVT) in providing early symptom relief and decreasing the incidence of post-thrombotic syndrome (PTS), especially severe PTS. However, the impact of quantum of residual thrombus burden (RTB) on PTS as determined by intravascular ultrasound examination and the role of venous stenting in the acute setting have not been evaluated and represent the focus of this study.

METHODS

Sixty-nine limbs (65 patients) undergoing thrombus removal for acute symptomatic IFDVT between 2015 and 2021 formed the study cohort. The Venous Clinical Severity Score (VCSS) (range, 0-27) grade of swelling (GOS) (range, 0-4), and visual analog scale (VAS) pain scores (range, 0-10) were evaluated initially and at 6, 12, and 24 months after thrombus removal. Quality of life was appraised using the CIVIQ-20 instrument. The extent of initial and RTB after the intervention was estimated using intravascular ultrasound examination. Grading was done as less than 50% (1), 50% to 99% (2), or 100% (3) of luminal thrombus fill within each segment (common femoral vein, external iliac vein, and common iliac vein) by a blinded rater and then combined to generate a total score. The use of stenting, both concurrent (severe residual stenosis/persistent occlusion) and delayed (quality of life impairing residual or recurrent symptoms), was evaluated.

RESULTS

Of the 69 limbs, 53 underwent pharmacomechanical/mechanical thrombectomy (PMT), whereas 16 patients underwent PMT and catheter-directed thrombolysis with restoration of inline flow in all limbs. Post-intervention VCSS improved from 6 to 2 at 24 months (P < .0001). GOS improved from 4 to 0 at 24 months (P < .0001). The VAS pain score went from 5 to 0 at 6 months (P < .0001) and remained at 0 at 12 months (P < .0001), but increased to 3 at 24 months (P = .02). The CIVIQ-20 score improved from 38 to 22 (P = .001) over a median follow-up of 19 months. The median RTB total score improved from 9 to 4 (P < .0001). There was no impact of RTB total score (<3 vs >3) on VCSS (P = NS), GOS (P = NS), VAS pain score (P = NS) or CIVIQ-20 score (P = NS) at the various time points. Concurrent stenting was used in 23 limbs (33%) and delayed stenting was carried out in 10 limbs (14%). The median time to delayed stenting was 4 months after the initial thrombus removal intervention.

CONCLUSIONS

In patients undergoing PMT or PMT with catheter-directed thrombolysis for acute symptomatic IFDVT, the restoration of inline flow seems to be adequate to provide symptom relief and decrease the incidence of PTS. The extent of RTB does not seem to impact the VCSS, GOS, VAS pain score, or quality of life after such restoration. Stenting can be pursued selectively in the acute setting to help restore inline flow.

Impact of concomitant popliteal vein thrombosis in patients with acute iliofemoral deep vein thrombosis treated with endovascular early thrombus removal

Summary: Background: Catheter-based thrombus removal (CBTR) reduces the risk of moderate to severe post-thrombotic syndrome (PTS) in patients with acute iliofemoral deep vein thrombosis (IF-DVT). However, the impact of concomitant popliteal DVT on clinical and duplex sonographic outcomes is unknown. Patients and methods: In this post-hoc analysis including the entire cohort of the randomized controlled BERNUTIFUL trial (48 patients), we compared clinical (incidence/severity of PTS assessed by Villalta score and revised venous clinical severity scores, rVCSS), disease-specific quality-of-life (QOL, CIVIQ-20 survey) and duplex sonographic outcomes (patency, reflux, post-thrombotic lesions) at 12 months follow-up between patients with IF-DVT with and without concomitant popliteal DVT treated by CBTR. Results: Overall, 48 IF-DVT patients were included (48% men, median age of 50 years), of whom 17 (35%) presented with popliteal DVT. At baseline, patients with popliteal DVT were older, had a higher body mass index and more important leg swelling. At 12 months, freedom from PTS (93% vs 87%, P=0.17), median total Villalta score (1 vs 1.5; P=0.46), rVCSS (2 vs 1.5, P=0.5) and disease-specific QOL (24 points vs 24 points, P=0.72) were similar between patient with and without popliteal DVT, respectively. Duplex sonographic outcomes were similar, except for more frequent popliteal post-thrombotic lesions and reflux (P=0.02) in patients with popliteal DVT. Conclusions: Relevant clinical outcomes 1 year after successful CBTR were favorable, regardless of the presence or absence of concomitant popliteal DVT. However, post-thrombotic popliteal vein lesions and reflux are more frequent in IF-DVT patients with popliteal involvement. Their impact on long-term outcomes remains to be investigated.

Catheter-directed thrombolysis for deep vein thrombosis: 2021 update

Catheter-directed thrombolysis (CDT) has been utilized as an adjunct to anticoagulant therapy in selected patients with deep vein thrombosis (DVT) for approximately 30 years. CDT used to be limited to patients with DVT causing acute limb threat and those exhibiting failure of initial anticoagulation, but has expanded over time. Randomized trials evaluating the first-line use of CDT for proximal DVT have demonstrated that CDT does not produce a major reduction in the occurrence of post-thrombotic syndrome (PTS) and that it is poorly suited for elderly patients and those with limited thrombus extent or major risk factors for bleeding. However, CDT does offer selected patients with acute iliofemoral DVT improvement in reducing early DVT symptoms, in achieving reduction in PTS severity, and in producing an improvement in health-related quality of life (QOL). Clinical practice guidelines from medical and surgical societies are now largely aligned with the randomized trial results. This review offers the reader an update on the results of recently completed clinical trials, and additional guidance on appropriate selection of patients with DVT for catheter-directed thrombolytic therapy.

Thrombolytic strategies versus standard anticoagulation for acute deep vein thrombosis of the lower limb

BACKGROUND

Standard treatment for deep vein thrombosis (DVT) aims to reduce immediate complications. Use of thrombolytic clot removal strategies (i.e. thrombolysis (clot dissolving drugs), with or without additional endovascular techniques), could reduce the long-term complications of post-thrombotic syndrome (PTS) including pain, swelling, skin discolouration, or venous ulceration in the affected leg. This is the fourth update of a Cochrane Review first published in 2004.

OBJECTIVES

To assess the effects of thrombolytic clot removal strategies and anticoagulation compared to anticoagulation alone for the management of people with acute deep vein thrombosis (DVT) of the lower limb.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and AMED and the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov trials registries to 21 April 2020. We also checked the references of relevant articles to identify additional studies.

SELECTION CRITERIA

We considered randomised controlled trials (RCTs) examining thrombolysis (with or without adjunctive clot removal strategies) and anticoagulation versus anticoagulation alone for acute DVT.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as recommended by Cochrane. We assessed the risk of bias in included trials with the Cochrane 'Risk of bias' tool. Certainty of the evidence was evaluated using GRADE. For dichotomous outcomes, we calculated the risk ratio (RR) with the corresponding 95% confidence interval (CI). We pooled data using a fixed-effect model, unless we identified heterogeneity, in which case we used a random-effects model. The primary outcomes of interest were clot lysis, bleeding and post thrombotic syndrome.

MAIN RESULTS

Two new studies were added for this update. Therefore, the review now includes a total of 19 RCTs, with 1943 participants. These studies differed with respect to the thrombolytic agent, the doses of the agent and the techniques used to deliver the agent. Systemic, loco-regional and catheter-directed thrombolysis (CDT) strategies were all included. For this update, CDT interventions also included those involving pharmacomechanical thrombolysis. Three of the 19 included studies reported one or more domain at high risk of bias. We combined the results as any (all) thrombolysis interventions compared to standard anticoagulation. Complete clot lysis occurred more frequently in the thrombolysis group at early follow-up (RR 4.75; 95% CI 1.83 to 12.33; 592 participants; eight studies) and at intermediate follow-up (RR 2.42; 95% CI 1.42 to 4.12; 654 participants; seven studies; moderate-certainty evidence). Two studies reported on clot lysis at late follow-up with no clear benefit from thrombolysis seen at this time point (RR 3.25, 95% CI 0.17 to 62.63; two studies). No differences between strategies (e.g. systemic, loco-regional and CDT) were detected by subgroup analysis at any of these time points (tests for subgroup differences: P = 0.41, P = 0.37 and P = 0.06 respectively). Those receiving thrombolysis had increased bleeding complications (6.7% versus 2.2%) (RR 2.45, 95% CI 1.58 to 3.78; 1943 participants, 19 studies; moderate-certainty evidence). No differences between strategies were detected by subgroup analysis (P = 0.25). Up to five years after treatment, slightly fewer cases of PTS occurred in those receiving thrombolysis; 50% compared with 53% in the standard anticoagulation (RR 0.78, 95% CI 0.66 to 0.93; 1393 participants, six studies; moderate-certainty evidence). This was still observed at late follow-up (beyond five years) in two studies (RR 0.56, 95% CI 0.43 to 0.73; 211 participants; moderate-certainty evidence). We used subgroup analysis to investigate if the level of DVT (iliofemoral, femoropopliteal or non-specified) had an effect on the incidence of PTS. No benefit of thrombolysis was seen for either iliofemoral or femoropopliteal DVT (six studies; test for subgroup differences: P = 0.29). Systemic thrombolysis and CDT had similar levels of effectiveness. Studies of CDT included four trials in femoral and iliofemoral DVT, and results from these are consistent with those from trials of systemic thrombolysis in DVT at other levels of occlusion.

AUTHORS' CONCLUSIONS

Complete clot lysis occurred more frequently after thrombolysis (with or without additional clot removal strategies) and PTS incidence was slightly reduced. Bleeding complications also increased with thrombolysis, but this risk has decreased over time with the use of stricter exclusion criteria of studies. Evidence suggests that systemic administration of thrombolytics and CDT have similar effectiveness. Using GRADE, we judged the evidence to be of moderate-certainty, due to many trials having small numbers of participants or events, or both. Future studies are needed to investigate treatment regimes in terms of agent, dose and adjunctive clot removal methods; prioritising patient-important outcomes, including PTS and quality of life, to aid clinical decision making.

Predictors of long-term post-thrombotic syndrome following high proximal deep vein thrombosis: a cross-sectional study

Background

Post-thrombotic syndrome (PTS) is a frequent chronic complication of proximal deep vein thrombosis (DVT) of the lower limb, but predictors of PTS are not well established. We aimed to examine predictors of PTS in patients with long-term PTS following proximal DVT.

Methods

During 2006–09, 209 patients with a first time acute upper femoral or iliofemoral DVT were randomized to receive either additional catheter-directed thrombolysis or conventional therapy alone. In 2017, the 170 still-living participants were invited to participate in a cross-sectional follow-up study. In the absence of a gold standard diagnostic test, PTS was defined in line with clinical practice by four mandatory, predefined clinical criteria: 1. An objectively verified DVT; 2. Chronic complaints (> 1 month) in the DVT leg; 3. Complaints appeared after the DVT; and 4. An alternative diagnosis was unlikely. Possible predictors of PTS were identified with multivariate logistic regression.

Results

Eighty-eight patients (52%) were included 8–10 years following the index DVT, and 44 patients (50%) were diagnosed with PTS by the predefined clinical criteria. Younger age and higher baseline Villalta score were found to be independent predictors of PTS, i.e., OR 0.96 (95% CI, 0.93–0.99), and 1.23 (95% CI, 1.02–1.49), respectively. Lack of iliofemoral patency at six months follow-up was significant in the bivariate analysis, but did not prove to be significant after the multivariate adjustments.

Conclusions

In long-term follow up after high proximal DVT, younger age and higher Villalta score at DVT diagnosis were independent predictors of PTS.

Correlation between Post-Procedure Residual Thrombus and Clinical Outcome in Deep Vein Thrombosis Patients Receiving Pharmacomechanical Thrombolysis in a Multicenter Randomized Trial

PURPOSE

To evaluate relationships between immediate venographic results and clinical outcomes of pharmacomechanical catheter-directed thrombolysis (PCDT).

MATERIALS AND METHODS

Venograms from 317 patients with acute proximal deep vein thrombosis (DVT) who received PCDT in a multicenter randomized trial were reviewed. Quantitative thrombus resolution was assessed by independent readers using a modified Marder scale. The physician operators recorded their visual assessments of thrombus regression and venous flow. These immediate post-procedure results were correlated with patient outcomes at 1, 12, and 24 months.

RESULTS

PCDT produced substantial thrombus removal (P < .001 for pre-PCDT vs. post-PCDT thrombus scores in all segments). At procedure end, spontaneous venous flow was present in 99% of iliofemoral venous segments and in 89% of femoral-popliteal venous segments. For the overall proximal DVT population, and for the femoral-popliteal DVT subgroup, post-PCDT thrombus volume did not correlate with 1-month or 24-month outcomes. For the iliofemoral DVT subgroup, over 1 and 24 months, symptom severity scores were higher (worse), and venous disease-specific quality of life (QOL) scores were lower (worse) in patients with greater post-PCDT thrombus volume, with the difference reaching statistical significance for the 24-month Villalta post-thrombotic syndrome (PTS) severity score (P = .0098). Post-PCDT thrombus volume did not correlate with 12-month valvular reflux.

CONCLUSIONS

PCDT successfully removes thrombus in acute proximal DVT. However, the residual thrombus burden at procedure end does not correlate with the occurrence of PTS during the subsequent 24 months. In iliofemoral DVT, lower residual thrombus burden correlates with reduced PTS severity and possibly also with improved venous QOL and fewer early symptoms.

Factors associated with the development of post-thrombotic syndrome in patients with iliofemoral deep venous thrombosis who underwent catheter-directed thrombolysis

OBJECTIVE

To identify predictors of post-thrombotic syndrome in patients with iliofemoral deep venous thrombosis who underwent catheter-directed thrombolysis.

METHODS

Fifty-two consecutive patients who underwent catheter-directed thrombolysis were included in this retrospective study. In addition to catheter-directed thrombolysis, aspiration thrombectomy or stent placement was performed if needed. At six months, duplex ultrasound was performed to assess iliofemoral patency and deep venous reflux. Post-thrombotic syndrome was assessed using the clinical, etiologic, anatomic, and pathophysiologic classification (post-thrombotic syndrome present ≥3 on a scale from 0 to 6). Univariate analysis and multivariate logistic regression were used to identify predictors of post-thrombotic syndrome.

RESULTS

Median follow-up was 52 months and post-thrombotic syndrome developed in nine patients (17.3%). In univariate analysis, stent placement (odds ratio 0.16, p = 0.022) was negatively associated with post-thrombotic syndrome, whereas iliofemoral venous obstruction with reflux at six months (OR 6.08, p = 0.037) was positively associated with post-thrombotic syndrome. Multivariate analysis indicated that stent placement was associated with reduced risk of post-thrombotic syndrome (OR 0.17, p = 0.043), and iliofemoral obstruction with reflux was associated with increased risk (OR 6.67, p = 0.046).

CONCLUSION

Stent placement and iliofemoral venous obstruction with reflux, respectively, were important protective and risk factors for post-thrombotic syndrome in patients who underwent catheter-directed thrombolysis.

Relationships between the use of pharmacomechanical catheter-directed thrombolysis, sonographic findings, and clinical outcomes in patients with acute proximal DVT: Results from the ATTRACT Multicenter Randomized Trial

Few studies have documented relationships between endovascular therapy, duplex ultrasonography (DUS), post-thrombotic syndrome (PTS), and quality of life (QOL). The Acute Venous Thrombosis: Thrombus Removal with Adjunctive Catheter-Directed Thrombolysis (ATTRACT) trial randomized 692 patients with acute proximal deep vein thrombosis (DVT) to receive anticoagulation or anticoagulation plus pharmacomechanical catheter-directed thrombolysis (PCDT). Compression DUS was obtained at baseline, 1 month and 12 months. Reflux DUS was obtained at 12 months in a subset of 126 patients. Clinical outcomes were collected over 24 months. At 1 month, patients who received PCDT had less residual thrombus compared to Control patients, evidenced by non-compressible common femoral vein (CFV) (21% vs 35%, p < 0.0001), femoral vein (51% vs 70%, p < 0.0001), and popliteal vein (61% vs 74%, p < 0.0001). At 12 months, in the ultrasound substudy, valvular reflux prevalence was similar between groups (85% vs 91%, p = 0.35). CFV non-compressibility at 1 month was associated with higher rates of any PTS (61% vs 46%, p < 0.001), a higher incidence of moderate-or-severe PTS (30% vs 19%, p = 0.003), and worse QOL (difference 8.2 VEINES-QOL (VEnous INsufficiency Epidemiological and Economic Study on Quality of Life) points; p = 0.004) at 24 months. Valvular reflux at 12 months was associated with moderate-or-severe PTS at 24 months (30% vs 0%, p = 0.01). In summary, PCDT results in less residual thrombus but does not reduce venous valvular reflux. CFV non-compressibility at 1 month is associated with more PTS, more severe PTS, and worse QOL at 24 months. Valvular reflux may predispose to moderate-or-severe PTS. ClinicalTrials.gov Identifier NCT00790335.

Cessation of anticoagulation therapy following endovascular thrombus removal and stent placement for acute iliofemoral deep vein thrombosis

Summary. Background: The optimal duration of anticoagulation therapy (AT) following catheter-based therapy of acute iliofemoral deep vein thrombosis (IFDVT) with stent placement is unknown. Theoretically, resolving the underlying obstructive iliac vein lesion by a stent may eliminate the main trigger for recurrence, the post-thrombotic syndrome (PTS), and the need for extended-duration AT. Patients and methods: From 113 patients with acute IFDVT who underwent endovascular thrombus removal and stent placement, we compared patency rates and clinical outcomes between 58 patients on limited-duration AT (3–12 month) and 55 patients on extended-duration AT (> 12 months). Results: Mean follow-up duration was 26 ± 18 (range 3–77) months; it was 24 ± 18 (range 3–69) months after cessation of AT in the limited-duration AT group. In comparison to patients with extended-duration AT, patients with limited-duration AT were younger (38 versus 54 years; p < 0.001), more often female (74 % versus 49 %; p = 0.01), and had less often prior venous thromboembolism (VTE) (9 % versus 35 %; p = 0.001). May-Thurner syndrome was more frequent in the limited-duration AT group (66 % versus 38 %; p = 0.004). Overall, primary and secondary patency rates at 24 months were 80 % (95 % CI, 70–87 %) and 95 % (95 % CI, 88–98 %), respectively, with no difference between the groups. Overall, 17 (15 %) patients developed recurrent VTE, of which 14 (82 %) events were thrombotic stent occlusions, and 13 (76 %) events occurred during AT. In the limited-duration AT group, 98 % patients were free from the PTS at two years with a VTE recurrence rate of 3.5 per 100 patient years after cessation of AT. Conclusions: In selected patients with acute IFDVT and patent venous stent, particularly in younger and otherwise healthy patients with May-Thurner syndrome, it appears to be safe to discontinue AT 3–12 months after endovascular treatment. Clinical Trial Registration: The study is registered on the National Institutes of Health website (ClinicalTrials.gov; identifier NCT02433054).

The case for catheter-directed thrombolysis in selected patients with acute proximal deep vein thrombosis

This article has a companion Counterpoint by Poston and Garcia.

Rivaroxaban or vitamin-K antagonists following early endovascular thrombus removal and stent placement for acute iliofemoral deep vein thrombosis

BACKGROUND

The optimal anticoagulant following catheter-based therapy of acute iliofemoral deep vein thrombosis (IFDVT) is unknown.

METHODS

From the Swiss Venous Stent registry, an ongoing prospective cohort study, we performed a subgroup analysis of patients with acute IFDVT who underwent catheter-based early thrombus removal followed by nitinol stent placement. Duplex ultrasound and Villalta scores were used to determine patency rates and incidence of the post-thrombotic syndrome (PTS) in patients treated with either rivaroxaban (n = 73) or a vitamin K-antagonist (VKA; n = 38) for a minimum duration of 3 months.

RESULTS

Mean follow-up duration was 24 ± 19 months (range 3 to 77 months). Anticoagulation therapy was time-limited (3 to 12 months) in 56% of patients (47% in the rivaroxaban group and 58% in the VKA group, p = 0.26), with shorter mean duration of anticoagulation in the rivaroxaban group (180 ± 98 days versus 284 ± 199 days, p = 0.01). Overall, primary and secondary patency rates at 24 months were 82% (95%CI, 71-89%) and 95% (95%CI, 87-98%), respectively, with no difference between the rivaroxaban (87% [95%CI, 76-94%] and 95% [95%CI, 85-98%]) and the VKA group (72% [95%CI, 52-86%] and 94% [95%CI, 78-99%]; p > 0.10 for both). Overall, 86 (86%) patients were free from PTS at latest follow-up, with no difference between the rivaroxaban and the VKA groups (57 [85%] versus 29 [88%]; p = 0.76). Two major bleeding complications (1 in each group) occurred in the peri-interventional period, without any major bleeding thereafter.

CONCLUSIONS

In patients with acute IFDVT treated with catheter-based early thrombus removal and venous stent placement, the effectiveness and safety of rivaroxaban and VKA appear to be similar.

CLINICAL TRIAL REGISTRATION

The study is registered on the National Institutes of Health website (ClinicalTrials.gov; identifier NCT02433054).

Catheter-directed thrombolysis through anterior tibial vein for treating acute extensive deep venous thrombosis

OBJECTIVE

The objective of this study was to evaluate the feasibility, efficacy, and safety of catheter-directed thrombolysis (CDT) through an anterior tibial vein approach for acute extensive lower extremity deep venous thrombosis (DVT).

METHODS

There were 125 consecutive patients with acute extensive lower extremity DVT who received CDT through an anterior tibial vein approach between October 2014 and June 2017. The patients with iliac vein compression syndrome were treated with balloon dilation and stent implantation after CDT. The thrombus score differences, limb circumference differences, venous patency, and complications were retrospectively analyzed.

RESULTS

The anterior tibial vein approach was successfully achieved in 118 patients (94.40% [118/125]). The mean thrombolysis time was 5.28 ± 1.10 days, and the average dose of urokinase was 3,903,400 ± 766,900 IU. Metal stents were placed in 50 patients (42.37% [50/118]). There were 109 patients (92.37% [109/118]) who had successful lysis (grade II and grade III lysis); 31 patients (91.18% [31/34]) achieved grade III lysis (no residual thrombus) within 3 days of symptom onset. In contrast, only 33.96% (18/53) of those treated within 4 to 7 days and 9.68% (3/31) of those treated after 7 days achieved grade III lysis. Compared with findings before CDT, the limb circumference above and below the knee was significantly reduced (7.22 ± 2.54 cm vs 1.58 ± 0.75 cm and 5.14 ± 1.41 cm vs 1.19 ± 0.49 cm, respectively). The incidence of bleeding was 10.17% (12/118). Six patients had puncture site bleeding, and three patients suffered major bleeding. One puncture site infection and two catheter-directed infections were observed during treatment. Two patients had accidental anterior tibial artery injury and recovered without complications, and no nerve injury occurred. During a follow-up of 19.39 ± 7.47 months (6-32 months), femoral venous insufficiency and popliteal venous insufficiency were present in 21.65% (21/97) and 30.93% (30/97) of the patients. The overall patency and post-thrombotic syndrome rates were 83.51% (81/97) and 21.65% (21/97).

CONCLUSIONS

CDT through an anterior tibial vein approach is a feasible, effective, and safe method for acute extensive lower extremity DVT patients. In addition, the anterior tibial vein approach can be an alternative to the traditional CDT approach.

Ultrasound-assisted versus conventional catheter-directed thrombolysis for acute iliofemoral deep vein thrombosis: 1-year follow-up data of a randomized-controlled trial

Essentials Acute iliofemoral deep vein thrombosis can be treated with catheter-directed thrombolysis (CDT). We performed a randomized trial comparing conventional CDT versus ultrasound-assisted CDT (USAT). Clinical and duplex sonographic outcomes at 12 months were similar in the CDT and USAT groups. In both groups, incidence of postthrombotic syndrome was very low with good quality of life.

SUMMARY

Background In patients with acute iliofemoral deep vein thrombosis (IFDVT), catheter-directed thrombolysis (CDT) aims to prevent the postthrombotic syndrome (PTS). Adding intravascular high-frequency, low-power ultrasound energy to CDT does not seem to improve the immediate thrombolysis results but its impact on clinical outcomes at 12 months is not known. Patients/Methods In this randomized-controlled trial, 48 patients (mean age 50 ± 21 years; 52% women) with acute IFDVT were randomized to conventional CDT (n = 24) or ultrasound-assisted CDT (USAT; n = 24). In both groups, a fixed-dose thrombolysis regimen (20 mg r-tPA over 15 h) was used, followed by routine stenting of residual venous obstruction. At 12 months, PTS and venous disease severity (Villalta score and revised Venous Clinical Severity Score [rVCSS]), disease-specific quality of live (QOL; CIVIQ-20) and duplex-sonographic outcomes were assessed. Results Among the 45 surviving patients, 40 (89%; 95% confidence interval [CI] 76-96%) patients were free from PTS (defined as Villalta score < 5 points; 83%, 95% CI 61-95% in the USAT and 96%, 95% CI 77-100% in the CDT group), with a similar mean total Villalta score of 2.3 ± 2.9 vs. 1.7 ± 1.6, and a mean total rVCSS of 3.0 ± 3.5 vs. 2.7 ± 2.9 in the USAT and the CDT groups, respectively. Both groups had good disease-specific QOL with a CIVIQ-20 score of 29.4 ± 11.8 vs. 26.1 ± 7.8, respectively. Primary (100% vs. 92%) and secondary (100% vs. 96%) iliofemoral patency rates and presence of femoro-popliteal venous reflux (39% vs. 33%) were similar in both groups. Conclusion The addition of intravascular ultrasound energy to conventional CDT for the treatment of acute IFDVT did not have any impact on relevant clinical or duplex sonographic outcomes, which were favorable in both study groups. Clinical Trial Registration URL: http://www.clinicaltrials.gov. Unique identifier:NCT01482273.

The postthrombotic syndrome: current evidence and future challenges

Postthrombotic syndrome (PTS) is a chronic complication of deep vein thrombosis (DVT) that develops in 20-50% of patients. PTS manifests as a spectrum of symptoms and signs of chronic venous insufficiency that can impose significant morbidity and have a negative impact on quality of life. Chronic venous hypertension caused by a combination of residual venous obstruction and valvular reflux is believed to play a major role in the pathophysiology of PTS. The Villalta scale is the most widely applied clinical scale used to diagnose and define PTS. Proximal DVT and recurrent ipsilateral DVT are the two principal established risk factors for PTS, and efforts in recent years have been focused on identifying a combination of clinical and biomarker predictors that will define high-risk patients and possibly new therapeutic targets. The best way to prevent PTS is to prevent the occurrence of DVT, and to provide optimal anticoagulation for the acute phase of DVT once it occurs. Recent years have brought progress in our understanding of the role of endovascular techniques in the prevention and treatment of PTS and the subgroups of patients that may benefit from these modalities. Pharmacomechanical catheter-directed thrombolysis is the most promising interventional modality for prevention of PTS. This review summarizes the current state of evidence on PTS of the lower limbs, and highlights areas where uncertainty still exists that require further research.

Should catheter-directed thrombolysis be monitored?

Catheter-directed thrombolysis for deep venous thrombosis is considered the basic treatment modality for intrathrombus removal. This method is preferably used in patients with iliofemoral deep venous thrombosis due to poor spontaneous recanalization in this segment, especially on the left side. The method was published almost 25 years ago and has gained ground in the treatment because of poor results from systemic thrombolysis and because of the possibility of stenting any underlying iliac obstruction during the procedure. However, the publications of catheter-directed thrombolysis reveal a great heterogeneity concerning catheter-directed thrombolysis technique and the lack of high quality evidence about monitoring as a tool to minimize the risk of bleeding and pulmonary embolism. Strict inclusion and exclusion criteria, correct composition and infusion of thrombolysis agent, imaging thrombus clearance during catheter-directed thrombolysis, ensuring flow enhancement during the bedridden situation, careful evaluation of indication for stenting based on imaging, and sufficient conversion to anticoagulation treatment following catheter-directed thrombolysis are essential. The aim of this paper is to discuss different treatment aspects of catheter-directed thrombolysis for iliofemoral thrombosis and to suggest a monitoring model for future treatment.

Thrombolysis for acute deep vein thrombosis

BACKGROUND

Standard treatment for deep vein thrombosis aims to reduce immediate complications. Use of thrombolysis or clot dissolving drugs could reduce the long-term complications of post-thrombotic syndrome (PTS) including pain, swelling, skin discolouration, or venous ulceration in the affected leg. This is the third update of a review first published in 2004.

OBJECTIVES

To assess the effects of thrombolytic therapy and anticoagulation compared to anticoagulation alone for the management of people with acute deep vein thrombosis (DVT) of the lower limb as determined by the effects on pulmonary embolism, recurrent venous thromboembolism, major bleeding, post-thrombotic complications, venous patency and venous function.

SEARCH METHODS

For this update the Cochrane Vascular Information Specialist (CIS) searched the Specialised Register (February 2016). In addition the CIS searched the Cochrane Register of Studies (CENTRAL (2016, Issue 1)). Trial registries were searched for details of ongoing or unpublished studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) examining thrombolysis and anticoagulation versus anticoagulation for acute DVT were considered.

DATA COLLECTION AND ANALYSIS

For this update (2016), LW and CB selected trials, extracted data independently, and sought advice from MPA where necessary. We assessed study quality with the Cochrane risk of bias tool. For dichotomous outcomes, we calculated the risk ratio (RR) and corresponding 95% confidence interval (CI). Data were pooled using a fixed-effect model unless significant heterogeneity was identified in which case a random-effects model was used. GRADE was used to assess the overall quality of the evidence supporting the outcomes assessed in this review.

MAIN RESULTS

Seventeen RCTs with 1103 participants were included. These studies differed in the both thrombolytic agent used and in the technique used to deliver it. Systemic, loco-regional and catheter-directed thrombolysis (CDT) were all included. Fourteen studies were rated as low risk of bias and three studies were rated as high risk of bias. We combined the results as any (all) thrombolysis compared to standard anticoagulation. Complete clot lysis occurred significantly more often in the treatment group at early follow-up (RR 4.91; 95% CI 1.66 to 14.53, P = 0.004) and at intermediate follow-up (RR 2.44; 95% CI 1.40 to 4.27, P = 0.002; moderate quality evidence). A similar effect was seen for any degree of improvement in venous patency. Up to five years after treatment significantly less PTS occurred in those receiving thrombolysis (RR 0.66, 95% CI 0.53 to 0.81; P < 0.0001; moderate quality evidence). This reduction in PTS was still observed at late follow-up (beyond five years), in two studies (RR 0.58, 95% CI 0.45 to 0.77; P < 0.0001; moderate quality evidence). Leg ulceration was reduced although the data were limited by small numbers (RR 0.87; 95% CI 0.16 to 4.73, P = 0.87). Those receiving thrombolysis had increased bleeding complications (RR 2.23; 95% CI 1.41 to 3.52, P = 0.0006; moderate quality evidence). Three strokes occurred in the treatment group, all in trials conducted pre-1990, and none in the control group. There was no significant effect on mortality detected at either early or intermediate follow-up. Data on the occurrence of pulmonary embolism (PE) and recurrent DVT were inconclusive. Systemic thrombolysis and CDT had similar levels of effectiveness. Studies of CDT included two trials in femoral and iliofemoral DVT, and results from these are consistent with those from trials of systemic thrombolysis in DVT at other levels of occlusion.

AUTHORS' CONCLUSIONS

Thrombolysis increases the patency of veins and reduces the incidence of PTS following proximal DVT by a third. Evidence suggests that systemic administration and CDT have similar effectiveness. Strict eligibility criteria appears to improve safety in recent studies and may be necessary to reduce the risk of bleeding complications. This may limit the applicability of this treatment. In those who are treated there is a small increased risk of bleeding. Using GRADE assessment, the evidence was judged to be of moderate quality due to many trials having low numbers of participants. However, the results across studies were consistent and we have reasonable confidence in these results.

Post-thrombotic syndrome after catheter-directed thrombolysis for deep vein thrombosis (CaVenT): 5-year follow-up results of an open-label, randomised controlled trial

BACKGROUND

Post-thrombotic syndrome is a common complication after acute proximal deep vein thrombosis (DVT) and is associated with reduced quality of life and a substantial cost burden. In the 2-year results of the CaVenT study, additional catheter-directed thrombolysis reduced the risk of post-thrombotic syndrome by 14% compared with conventional therapy, but did not affect quality of life. In this study we report results at the 5-year follow-up, aiming to assess whether findings for post-thrombotic syndrome and quality of life have persisted.

METHODS

Between Jan 3, 2006, and Dec 22, 2009, we recruited patients aged 18-75 years with a first-time high proximal leg DVT from 20 hospitals in the Norwegian southeastern health region. With sealed envelopes, participants were randomly assigned (1:1) to standard treatment with compression stockings and anticoagulants (control group) or to standard treatment plus catheter-directed thrombolysis with alteplase within 21 days from symptom onset. Pre-specified outcomes in this analysis were post-thrombotic syndrome at 5 years as assessed with the Villalta score and scores for quality of life at 5 years with EQ-5D and the disease-specific VEINES-QOL/Sym. Analyses were by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00251771.

FINDINGS

At 5 year follow-up (last date Oct 14, 2014), data were available for 176 patients (84% of the 209 patients originally randomised)--87 originally assigned to catheter-directed thrombolysis and 89 originally assigned to the control group. 37 patients (43%; 95% CI 33-53) allocated to catheter-directed thrombolysis developed post-thrombotic syndrome, compared with 63 (71%; 95% CI 61-79) allocated to the control group (p<0·0001), corresponding to an absolute risk reduction of 28% (95% CI 14-42) and a number needed to treat of 4 (95% CI 2-7). Four (5%) patients assigned to catheter-directed thrombolysis and one (1%) to standard treatment had severe post-thrombotic syndrome (Villalta score ≥ 15 or presence of an ulcer). Quality-of-life scores with either assessment scale did not differ between the treatment groups.

INTERPRETATION

Additional catheter-directed thrombolysis resulted in a persistent and increased clinical benefit during follow-up for up to 5 years, supporting the use of additional catheter-directed thrombolysis in patients with extensive proximal DVT. However, allocation to this therapy did not lead to better quality of life. The optimal endovascular thrombolytic approach needs further investigation.

FUNDING

Southeastern Norway Regional Health Authority, the Research Council of Norway, University of Oslo, Oslo University Hospital.