The background and role of catheter-directed thrombolysis evolving procedures for acute iliofemoral deep venous thrombosis

Minimal invasive treatment such as early endovenous thrombus removal for iliofemoral deep venous thrombosis (DVT) emerged in the end of last century. The principle is catheter-directed thrombolysis (CDT) using either plasminogen activating agents alone, as ultrasound-assisted CDT, or in combination with mechanical devices as pharmaco-mechanical CDT. The interest for this treatment modality is the high rate of post-thrombotic syndrome (PTS) with anticoagulation (AC) alone, especially after iliofemoral DVT. Recently published randomized controlled trials (RCTs) comparing early thrombus removal with AC alone, as well as non-randomized studies, have demonstrated favorable rates, or at least a decrease of moderate and severe PTS, in favor of these procedures. This article will summarize the background and evolution of the procedures in the last three decades and discuss fundamental criteria for inclusion and exclusion, focusing on the procedures regarding thrombus age and location, technical issues, complications and results including different outcome measures for PTS, for which iliac DVT involvement is a massive risk factor to be prevented.

Endovascular Repair of Iatrogenic Inferior Vena Cava and Iliac Vein Injury: A Case Series and Review of the Literature

OBJECTIVE

Iatrogenic injury to the large abdominopelvic veins can he highly morbid, and open surgical repair is technically challenging. Endovascular repair with covered stenting across the injured segment offers an alternative to open surgical management. We present a series of patients with operative injury to the inferior vena cava (IVC) and iliac veins who were treated utilizing an endovascular approach and review the available literature on this technique.

METHODS

A PubMed keyword and MeSH term search was performed, and titles were reviewed for relevance by the first author. Studies related to endovascular repair of iatrogenic injury to the IVC and iliac veins were then read in detail for possible inclusion in the review. Those deemed appropriate were further analyzed for interventional approach, stent type and size, technical success, post-procedural pharmacologic management, complications and surveillance strategy.

RESULTS

The initial search resulted in 6221 publications. A total of 17 met criteria for inclusion, all of which were case reports or series. Twenty-six patients were described as suffering iatrogenic injury to the IVC or iliac veins, treated with various types and sizes of stents. All cases achieved technical success with hemorrhage control. Procedural complications occurred in 15.4% of cases, including 3 cases of acute thrombus formation and 1 case of stenosis caudal to the initial stent edge requiring additional stenting. Two additional patients experienced stent occlusion in the surveillance period.

CONCLUSIONS

Endovascular repair of iatrogenic injury to the IVC and iliac veins can be an effective management option. However, due to limited data regarding this approach, many technical questions remain, including ideal size and type of stent graft, necessity and duration of post-procedural anticoagulant or antiplatelet therapy and appropriate surveillance. Additionally, long term outcomes in this population have not yet been described.

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.

Antithrombotic Therapy after Deep Venous Intervention

Chronic deep venous disease (CVD) can result in significant morbidity and impact on quality of life due to a spectrum of symptoms, including lower extremity edema, venous claudication, and venous ulcers. CVD can be secondary to both thrombotic and nonthrombotic disease processes, including postthrombotic syndrome from prior deep vein thrombosis (DVT) or iliac vein compression syndrome. Endovascular therapy has become a mainstay therapy for CVD patients, with venous stent placement frequently performed. However, the management of anticoagulation following venous stent placement is not well-studied, with no large trials or consensus guidelines establishing an optimal regimen. The current knowledge gap in antithrombotic therapy is magnified by heterogeneity in practice and data collection, along with incomplete reporting in available studies. Furthermore, most published datasets are antiquated in the setting of rapid evolution in technique and technology available for deep venous intervention. Herein, we summarize the current available literature and offer an approach to anticoagulation and antiplatelet management following deep venous intervention for CVD.

Self-Expandable Nitinol Stents for the Treatment of Nonmalignant Deep Venous Obstruction

BACKGROUND

Angioplasty with stent placement is a therapeutic option for patients with acute thrombotic, postthrombotic, and nonthrombotic obstruction of the iliofemoral veins or inferior vena cava. Previous studies of steel-alloy stents described variable patency rate across indications.

METHODS

The prospective Swiss Venous Stent Registry includes patients treated with self-expandable nitinol stents for deep venous obstruction. Routine follow-up visits include serial duplex ultrasound for stent patency assessment. The primary outcome was primary stent patency. The secondary outcome was venous thromboembolisms. We studied the rate of stent occlusion and potentially contributing factors.

RESULTS

We included 379 patients: 160 with acute thrombotic, 193 with postthrombotic, and 26 with nonthrombotic deep vein obstruction. The mean age was 46±18 years; 55% were women. The cumulative 3-year primary patency rate was 80.5% (95% CI, 73.0%-88.0%) for acute thrombotic, 59.2% (95% CI, 50.4%-68.0%) for postthrombotic, and 100% for nonthrombotic obstruction (log-rank, P<0.0001). Annualized rates of stent occlusion or venous thromboembolism were 7.8 (acute thrombotic), 15.0 (postthrombotic), and 0 (nonthrombotic) events/100 patient-years. In a multivariable Cox regression model, postthrombotic femoral veins at baseline (hazard ratio, 2.64 [95% CI, 1.53-4.56]) and the number of stents (hazard ratio, 1.22 [95% CI, 1.06-1.40]) were associated with stent occlusion after conditioning for age, sex, and clinically relevant factors.

CONCLUSIONS

The rate of stent occlusion (patency loss) and venous thromboembolism varies substantially across indications, also with dedicated venous nitinol stents. Patients with postthrombotic femoral veins and those who received multiple stents were characterized by the highest risk. Registration: URL: https://clinicaltrials.gov. Unique identifier: NCT02433054.

Antithrombotic Therapy after Venous Stent Placement

Chronic deep venous disease (CVD) affects millions of Americans and can result in significant morbidity, such as debilitating lower extremity oedema, venous claudication, and in severe cases, venous ulcers. CVD can be caused by thrombotic and non-thrombotic disease processes, such as deep venous thrombosis and iliac compression syndrome. Recently, endovascular intervention with percutaneous transluminal angioplasty and venous stent placement has become the mainstay therapy for these patients, with several studies demonstrating its safety and efficacy. However, anticoagulation management following venous stent placement is largely unstudied, and there are no large randomised controlled trials or official guidelines establishing an optimal regimen. Most published studies are plagued with data heterogeneity and incomplete reporting. This is further complicated by rapidly evolving improvements in technique and dedicated devices in endovenous intervention. In this article, the authors discuss the current literature to date and offer an approach to anticoagulation and antiplatelet management following venous stent placement in CVD.

Phlegmasia cerulea dolens - an uncommon but alarming manifestation of deep vein thrombosis

In phlegmasia cerulea dolens (PCD), immediate diagnosis and prompt treatment is crucial for limb salvage. Aggressive treatment options including venous intervention, thrombolysis and/or surgical thrombectomy should be considered. Due to the lack of data, the most appropriate intervention depends upon etiology of PCD, clinical presentation and patient's bleeding risk.

Duplex Ultrasound Investigation for the Detection of Obstructed Iliocaval Venous Stents

OBJECTIVE

Duplex ultrasound (DUS) is used for routine surveillance of stents in iliocaval veins, but direct visualisation is often challenging. Duplex ultrasound criteria for detecting venous stent obstruction (VSO) have not been defined to date.

METHODS

A nested case control study of 120 patients (42 ± 17 years, 53% women, mean 2.7 ± 1.8 stents) was performed, and the performance of various duplex parameters for detecting VSO (defined as > 50% lumen diameter reduction or occlusion) was tested, confirmed by biplane venography or intravascular ultrasound (IVUS). Forty patients with VSO (25 with stent occlusion, 15 with >50% in stent stenosis) were matched to 80 control patients by age, gender and index diagnosis who fulfilled the following criteria: (1) ongoing symptom control (Villalta score < 5), (2) good image quality of entire stent segment, (3) spontaneous colour Doppler signal > 50% of lumen in entire stent segment, (4) at least two DUS where the baseline DUS was obtained within 24 h after successful venous intervention.

RESULTS

The best test was the combination of peak flow velocity and flow pattern analysis at the stent inlet. A peak flow velocity >10 cm/s and a flow pattern spontaneously modulated by respiration ruled out VSO with a specificity of 93.7% (95% CI 86.0%-97.3%). A peak flow velocity ≤10 cm/s or any Doppler flow pattern other than spontaneously modulated by respiration was 92.1% (95% CI 79.2%-97.3%) sensitive to detect VSO.

CONCLUSION

The combination of peak flow velocity and analysis of Doppler flow pattern at the stent inlet is accurate to diagnose or rule out stent occlusion. Indirect criteria should always be combined with direct visualisation of iliocaval stents since those may be less sensitive for detecting stent stenosis.