Contemporary management of acute and chronic deep venous thrombosis

RevCore thrombectomy system for treatment of chronic left external and common iliac vein stent occlusion

In recent years, deep venous stenting has increasingly become a treatment strategy for post-thrombotic syndrome. Stent thrombosis can occur, resulting in symptom recurrence despite medical therapy, and there are few options available for durable stent patency restoration. We present a case of a 50-year-old male with prior iliocaval reconstruction that experienced recurrent left lower extremity swelling secondary to occlusion of left external iliac and common iliac vein stents during follow-up. Mechanical thrombectomy with the RevCore System and angioplasty was performed. One month later, the patient demonstrated widely patent bilateral iliac vein stents and complete symptomatic resolution. The RevCore System is a feasible alternative for treatment of chronic in-stent thrombosis.

A meta-analysis of the medium- to long-term outcomes in patients with chronic deep venous disease treated with dedicated venous stents

OBJECTIVE

This review summarizes the safety profile, stent patency, and clinical effectiveness of dedicated venous stents for the treatment of chronic deep venous disease. The approaches to stenting and post-procedural management of different vascular units are also explored.

METHODS

The MEDLINE and Embase databases were searched for pertinent literature published from January 2010 to January 2023. Outcomes related to post-stenting symptoms and health-related quality of life were described narratively. A meta analysis was conducted to evaluate stent patency, ulcer healing, bleeding, and 30-day stent thrombosis, and these outcomes were presented as proportion event rates.

RESULTS

Seventeen studies were identified comprising of 2218 patients. 62.7% of individuals had post-thrombotic stenosis or occlusion. The majority of patients (78.6%) were noted to have complete occlusions of their deep veins before stenting. Eleven different dedicated venous stents were deployed. At 12 months, the primary patency rate was 83% (95% confidence interval [CI]: 76%-90%), the primary-assisted patency rate was 90% (95% CI: 85%-96%), and the secondary patency rate was 95% (95% CI: 92%-98%). A significant improvement in health-related quality of life was demonstrated after intervention. In total, 68.8% (95% CI: 52.0%-83.7%) of ulcers healed at the last follow-up. The remaining symptomatic changes were described narratively; improvements in pain, venous claudication, and edema after stenting were observed. Seventeen deaths occurred, but none were linked to the stenting procedures. A total of 159 cases (7.2% of patients) of in-stent stenosis were observed, whereas 110 stents (5.0% of patients) were occluded. The incidence of major and minor bleeding was 1.7% (95% CI: 1.0%-2.5%) and 3.2% (95% CI: 1.3%-5.6%), respectively, more commonly seen in patients undergoing hybrid intervention.

CONCLUSIONS

Deep venous stenting using dedicated venous stents is a safe technique to treat chronic deep venous stenosis and/or occlusion. Within the limitations of this study, deep venous stenting is associated with good patency rates and symptomatic improvement.

Percutaneous mechanical thrombectomy to remove post-thrombotic obstructions and manage post-thrombotic syndrome-associated venous leg ulceration

BACKGROUND

Up to one half of patients with a diagnosis of deep vein thrombosis will develop post-thrombotic syndrome (PTS). Patients with PTS can develop venous leg ulcers (VLUs) due to post-thrombotic obstructions (PTOs) that contribute to prolonged ambulatory venous hypertension. The current treatments for PTS, which include chronic thrombus, synechiae, trabeculations, and inflow lesions, do not target PTOs, and such obstructions can affect stenting success. The aim of the present study was to determine whether removal of chronic PTOs using percutaneous mechanical thrombectomy would promote VLU resolution and positive outcomes.

METHODS

In this retrospective analysis, the characteristics and outcomes for patients with VLUs secondary to chronic PTO who were treated using the ClotTriever System (Inari Medical) between August 2021 and May 2022 were assessed. Technical success was considered the ability to cross a lesion and introduce the thrombectomy device. Clinical success was defined as a decrease of ≥1 in the severity category for the ulcer diameter using the revised venous clinical severity score (score 0, no VLU; score 1, mild VLU [size <2 cm]; score 2, moderate VLU [size 2-6 cm]; score 3, severe VLU [size >6 cm]) at the latest follow-up visit.

RESULTS

A total of 11 patients with 15 VLUs on 14 limbs were identified. Their mean age was 59.7 ± 11.8 years, and four patients (36.4%) were women. The median VLU duration was 11.0 months (interquartile range [IQR], 6.0-17.0 months), and 2 patients had VLUs secondary to a deep vein thrombosis event >40 years previously. All treatments were performed in a single session, with technical success achieved in 100% of the 14 limbs. A median of five passes (IQR, four to six passes) with the ClotTriever catheter were performed per limb. Chronic PTOs were successfully extirpated, and intraprocedural intravascular ultrasound showed effective disruption of venous synechiae and trabeculations. Stents were placed in 10 limbs (71.4%). The time to VLU resolution or the latest follow-up was 12.8 ± 10.5 weeks, and clinical success was achieved for all 15 VLUs (100%), with the revised venous clinical severity score for the ulcer diameter improving from a median of 2 (IQR, 2-2) at baseline to a median score of 0 (IQR, 0-0) at last follow-up. The VLU area had decreased by 96.6% ± 8.7%. Of the 15 VLUs, 12 (80.0%) had resolved completely, and 3 had demonstrated near-complete healing.

CONCLUSIONS

All patients showed complete or near-complete VLU healing within a few months after mechanical thrombectomy. Mechanical extirpation and interruption of chronic PTOs allowed for luminal gain and restoration of cephalad inflow. With additional investigation, mechanical thrombectomy with the study device could prove a vital component to the treatment of VLUs secondary to PTOs.

Symptomatic Chronic Severe Stenosis of the Iliac Vein Successfully Treated Endovascularly Using an Interventional Radiology Computed Tomography System

We report a woman with chronic severe stenosis of the left common and external iliac veins and severe post-thrombotic syndrome symptoms. We successfully recanalized the stenotic segment via interventional radiology, which immediately relieved the symptoms. The interventional radiology computed tomography system was helpful for the safe and precise performance of endovascular treatments.

Splanchnic Vein Thrombosis in Myeloproliferative Neoplasms: Treatment Considerations and Unmet Needs

Patients who develop splanchnic vein thrombosis (SVT) in the setting of a myeloproliferative neoplasm (MPN) are at risk for complications including portal hypertension, bleeding, thrombosis, and death. Prompt multidisciplinary treatment is thus necessary to prevent long-term sequelae. However, optimal management strategies are not well established due to a paucity of data. In this review, we very briefly discuss the epidemiology, pathophysiology, and prognosis of MPN-SVT and then more comprehensively explore treatment considerations of MPN-SVT, including anticoagulation, endovascular/surgical intervention, and cytoreductive therapy. We will also highlight current gaps in our knowledge of MPN-SVT and conclude by suggesting future directions to optimize the treatment of MPN-SVT and improve outcomes.

Chronic venous ulcer resolution and post-thrombotic syndrome improvement after percutaneous mechanical thrombectomy of a 42-year-old deep vein thrombosis

Post-thrombotic syndrome (PTS) is a chronic disease affecting up to one half of patients with deep vein thrombosis. PTS symptoms range in severity, with the worst form involving the development of venous ulcers. In the present report, we have described a patient with PTS with ulceration for >40 years. A percutaneous approach with a mechanical thrombectomy extirpation device was used to remove the chronic thrombus in a single session. At >3 months of follow-up, the PTS symptoms had improved dramatically, and the ulcer had completely healed. We have demonstrated successful removal of long-standing chronic thrombus using the ClotTriever system (Inari Medical, Irvine, CA) and the management of venous ulcers resulting from debilitating PTS.

Comparative Study of Diagnostic Efficacy of Single Phase-Computed Tomography Pulmonary Angiography and Dual Phase-Computed Tomography Pulmonary Angiography in the Diagnosis of Pulmonary Embolism

Objective

We compared the efficacy of single phase-computed tomography pulmonary angiography (SP-CTPA) and dual phase-computed tomography pulmonary angiography (DP-CTPA) for the diagnosis of pulmonary embolism (PE).

Methods

We recruited 1,019 consecutive patients (359 with PE) who underwent DP-CTPA (phase I: pulmonary artery phase; phase II: aortic phase) for suspected PE between January and October 2021. Phase I of DP-CTPA was used as SP-CTPA, and the final clinical diagnosis (FCD) was used as the gold standard.

Results

Three hundred fifty-two cases of PE were detected by both methods, with the same sensitivity of 98.1% (99.6–99.5%). Using SP-CTPA, 142 cases [13 pulmonary insufficiency artifacts (PIA) and 129 systemic-pulmonary shunt artifacts (S-PSA)] were false-positive with specificity of 78.5% (75.3–81.6%). No false-positive was found with DP-CTPA, with specificity of 100%, positive predictive value of 1, and negative predictive value of 0.990 (Net Reclassification Improvement = 0.215; P < 0.05). According to FCD, the positive results of SP-CTPA were divided into PIA, S-PSA, and true-positive (TP_SP−CTPA) groups, and pairwise comparisons were performed. The bronchiectasis and hemoptysis rate in S-PSA group was higher than that in PIA and TP groups (P < 0.001), and the pulmonary hypertension (PH) rate in PIA group was higher than that in S-PSA and TP groups (P < 0.001).

Conclusion

The diagnostic efficiency of DP-CTPA for the diagnosis of PE was high. SP-CTPA may misdiagnose PIA (common in patients with PH) and S-PSA (common in patients with bronchiectasis and hemoptysis) as PE.

Post-thrombotic Syndrome: Preventative and Risk Reduction Strategies Following Deep Vein Thrombosis

Venous disease is common in the general population, with chronic venous disorders affecting 50–85% of the western population and consuming 2–3% of healthcare funding. It, therefore, represents a significant socioeconomic, physical and psychological burden. Acute deep vein thrombosis, although a well-recognised cause of death through pulmonary embolism, can more commonly lead to post-thrombotic syndrome (PTS). This article summarises the pathophysiology and risk factor profile of PTS, and highlights various strategies that may reduce the risk of PTS, and the endovenous management of iliofemoral deep vein thrombosis. The authors summarise the advances in PTS risk reduction strategies and present the latest evidence for discussion.

Non-contrast-enhanced magnetic resonance imaging: Objective figures in differentiation between acute and chronic deep venous thrombosis in the lower extremities

BACKGROUND

Deep vein thrombosis is a severe health problem. Treatment options may differ between acute and chronic deep vein thrombosis. Thus, distinguishing acute from chronic deep vein thrombosis is essential for patients with deep vein thrombosis.Triggered angiography non-contrast enhanced is an innovative magnetic resonance imaging protocol that may provide objective evidence in differentiating acute from chronic deep vein thrombosis.

METHOD

We prospectively collected information on consecutive patients who had been evaluated through triggered angiography non-contrast enhanced magnetic resonance imaging for venous pathology in their lower extremities at a vascular wound care center in a tertiary hospital between April 2017 and January 2020. Patients included were divided into two groups with the onset time cutoff point of 21 days. All were undergone non-contrast-enhanced magnetic resonance imaging evaluation. Non-contrast-enhanced magnetic resonance imaging images were evaluated by a radiologist, and lower extremity venous thrombosis, collateral-vein development, and subcutaneous honeycombing were emphasized. Cohen's kappa coefficient was used to measure interrater agreement between the development of collateral veins, subcutaneous honeycombing, and symptom onset over 21 days.

RESULTS

Interrater agreement analysis revealed that the development of collateral veins was substantially correlated with the onset of symptoms over 21 days (Table 1). Additionally, the development of subcutaneous honeycombing detected through triggered angiography non-contrast enhanced magnetic resonance imaging also substantially agreed with the onset of symptoms over 21 days (Table 2).

CONCLUSION

The diagnostic power of triggered angiography non-contrast enhanced magnetic resonance imaging in deep vein thrombosis is rival to current gold standard, color Doppler sonography. Triggered angiography non-contrast enhanced magnetic resonance imaging provides objective information on onset timing in patients with deep vein thrombosis that could differentiate acute from chronic deep vein thrombosis and provides guidance for treatment planning.

In Vitro Thrombolytic Efficacy of Single- and Five-Cycle Histotripsy Pulses and rt-PA

Although primarily known as an ablative modality, histotripsy can increase the efficacy of lytic therapy in a retracted venous clot model. Bubble cloud oscillations are the primary mechanism of action for histotripsy, and the type of bubble activity is dependent on the pulse duration. A retracted human venous clot model was perfused with and without the thrombolytic recombinant tissue plasminogen activator (rt-PA). The clot was exposed to histotripsy pulses of single- or five-cycle duration and peak negative pressures of 0-30 MPa. Bubble activity within the clot was monitored via passive cavitation imaging. The combination of histotripsy and rt-PA was more efficacious than rt-PA alone for single- and five-cycle pulses with peak negative pressures of 25 and 20 MPa, respectively. For both excitation schemes, the detected acoustic emissions correlated with the degree of thrombolytic efficacy. These results indicate that rt-PA and single- or multicycle histotripsy pulses enhance thrombolytic therapy.

Midterm outcomes in postpartum women following endovenous treatment for acute iliofemoral deep vein thrombosis

BACKGROUND

The development of post-thrombotic syndrome (PTS) after iliofemoral deep vein thrombosis (DVT) continues to be a considerable issue for both pregnant and postpartum women with rates as high as 70% among those managed with anticoagulation alone. This study aims to characterize the outcomes of interventional treatment for acute iliofemoral DVT in this at-risk population.

METHODS

A retrospective analysis of all postpartum patients treated for acute iliofemoral DVT with lysis and stenting between January 2012 and December 2017 at a referral center. Patient demographics, risk factors, procedural factors. and complications were collected. Post-treatment outcomes were compared with all nonpostpartum females treated within the same time period. These included the severity of PTS evaluated using the Villalta scale, duration of vessel patency and factors affecting reintervention timing and success. Further detailed review of cases needing reintervention was also conducted through a retrospective review of documentation and an analysis of all imaging by a consultant radiologist.

RESULTS

A total of 11 postpartum women were identified. The median age was 28 years (range, 22-41 years) and intervention was performed at a median of 3 weeks after birth (range 2-12 weeks). No major or minor complications associated with intervention were reported in any patients. The median Villalta score was 3 at 6 months, improving to 2 at 12 months. Overall, two patients were classified as mild having PTS (18%), with no cases of moderate to severe PTS. On comparison with nonpostpartum (n = 68) Villalta scores, no significant difference in outcome was observed at 6 months (median score, 3; range, 0-15 months; P = .95) or at 1 year (median score, 1; range, 0-15; P = .84). Cumulative patency at 1 year was found to be 64% in postpartum women compared with 93% in nonpostpartum women. The postpartum state was found to be a significant predictor of cumulative patency loss (hazard ratio, 0.10; 95% confidence interval, 0.02-0.62; P = .01). However, no significant difference in primary and primary-assisted patency was observed. Of the postpartum patients, 55% required reintervention (6/11) compared with 29% of nonpostpartum patients (20/68). The mean time to initial reintervention was 62 days (range, 7-233 days). Reintervention was unsuccessful in all cases presenting with 100% vessel occlusion (4/11), but successful in both cases with partial occlusion (2/11). Analysis of the etiologic factors associated with reintervention revealed that all reintervention cases were associated with technical failure to fully lyse and stent beyond residual disease at the initial procedure. No technical, flow, or hematologic factors were identified in the four cases that retained primary patency.

CONCLUSIONS

This study suggests that percutaneous intervention to achieve early thrombus removal and venous stenting provides a favorable alternative to conservative therapies owing to its potential to decrease the severity of PTS. Completion of lysis and adequate stenting of disease is essential to prevent reocclusion, for which reintervention carries a lower likelihood of success. Further research is warranted to further characterize the appropriate management of postpartum women with iliofemoral DVT.

Non-invasive imaging techniques for the differentiation of acute and chronic thrombosis

Thrombosis is the localized clotting of blood that can occur in both the arterial and venous circulation. It is a key factor in the pathogenesis of acute coronary syndrome, myocardial infarction and stroke and the primary cause of deep vein thrombosis and pulmonary embolism. Rapid and accurate diagnosis of thrombotic episodes is crucial in reducing the morbidity and potential mortality associated with arterial and venous thrombotic disorders by allowing early targeted therapeutic interventions. From a clinical perspective the ability to accurately assess the age and composition of thrombus is highly desirable given that anticoagulation and, in particular, fibrinolytic therapies are more effective in treating acute rather than chronic thrombosis. While there are no imaging tests used in routine clinical practice that can reliably determine the age of thrombus and differentiate between acute and chronic thrombosis there are several emerging non-invasive techniques that can provide an indication of the age of a thrombus depending on its location in the body. Examples of techniques developed for venous thrombosis include Doppler imaging with venous duplex ultrasonography, ultrasound B-mode imaging integrated with IER (intrinsic mode functions-based echogenicity ratio), elastography, scintigraphy imaging with ^99mTc-recombinant tissue plasminogen activator (^99mTc-rt-PA), and magnetic resonance direct thrombus imaging (MDRTI). Magnetic resonance imaging (MRI) has been used to noninvasively detect and differentiate acute and chronic arterial and venous thrombosis. These methods have limitations that need further investigation to enable cost-effective and clinically relevant treatment practices to be established in the future. This review will discuss the difference between acute and chronic thrombosis and the role of non-invasive imaging techniques in discriminating between the two.

Early Venous Stent Failure Predicted by Platelet Count and Neutrophil/Lymphocyte Ratio

BACKGROUND

Inflammation and platelet activation have been shown to be involved in acute thromobogenicity following venous occlusive conditions. The aim of this study was to identify the association of baseline platelet count and neutrophil/lymphocyte ratio (NLR) with venous stent failure. Methods and Results: Patients who underwent technically successful iliocaval venous stent placement with available baseline complete blood count and follow-up stent patency data were selected (n=50). Stent failure was defined as >50% stenosis or occlusion at follow-up angiography, contrast-enhanced CT, MRI or duplex US. Median patient age was 49.5 years (range, 13-76 years), and 62% were female. Median follow-up time was 10.2 months (range, 0.1-76.4 months). Stent failure occurred in 13 patients (26%) after a median of 1.2 months (range, 1 day-76.4 months). On multivariable-adjusted Cox modeling, baseline platelets (HR, 2.28; P=0.004) and WBC count (HR, 2.03; P=0.013) were significantly associated with stent failure on follow-up; neutrophils (HR, 16.10; P=0.050); and NLR (HR, 12.19; P=0.050) had borderline significance. Compared with patients without stent failure, those with early, but not late, stent failure had higher baseline platelets (P=0.031) and neutrophils (P=0.025), and NLR (P=0.026).

CONCLUSIONS

Baseline platelet count and NLR are associated with early but not late failure of iliocaval venous stents. This suggests different pathophysiologic mechanisms and a role for both platelet activation and inflammatory mechanisms in early rather than late stent thrombosis. Future research is needed to better explain this novel finding.

Validation of the STA-Liatest DDi assay for exclusion of proximal deep vein thrombosis according to the latest Clinical and Laboratory Standards Institute/Food and Drug Administration guideline: results of a multicenter management study

: Recommended strategy for venous thromboembolism (VTE) diagnosis includes the use of sensitive D-dimer (DDi) assays along with pretest probability (PTP) assessment. The Clinical and Laboratory Standards Institute (CLSI) recently issued a guideline (US FDA endorsed) on DDi in VTE exclusion. Such guideline specifies the ideal D-dimer assay characteristics and target population. Demonstrate STA-LiatestD-Di performance combined with a PTP score for proximal deep vein thrombosis (pDVT) exclusion in a CLSI compliant study. International, multicenter, prospective nonrandomized, noninterventional clinical outcome management study conducted in a standard-of-care setting. DDi was measured in DVT-suspected consecutive low/moderate PTP outpatients, without conditions possibly impacting DDi values independently of thrombosis presence (age >80, pregnancy, postoperative, cancer) using a 0.5 μg/ml (FEU) threshold for DVT exclusion. Results were used to determine test performance. One thousand two hundred and thirty-four patients (17 centers) signed informed consent. Nine hundred and eighty (mean age: 55) with valid results (494 negative DDi) completed the study (DVT prevalence: 8.7%). STA-LiatestD-Di performance exceeded CLSI/FDA requirements: sensitivity: 100% (95% CI 95.8-100%), NPV: 100% (95% CI 99.3-100%). STA-LiatestD-Di associated with PTP score showed excellent performance for pDVT exclusion, as recently demonstrated for pulmonary embolism. The assay allows safe VTE exclusion, avoiding unnecessary imaging tests.

Impact of thrombosis on pulmonary endothelial injury and repair following sepsis

The prevailing morbidity and mortality in sepsis are largely due to multiple organ dysfunction (MOD), most commonly lung injury, as well as renal and cardiac dysfunction. Despite recent advances in defining many aspects of the pathogenesis of sepsis-related MOD, including acute respiratory distress syndrome (ARDS), there are currently no effective pharmacological or cell-based treatments for the disease. Human and animal studies have shown that pulmonary thrombosis is common in sepsis-induced ARDS, and preclinical studies have shown that anticoagulation may improve outcome following sepsis challenge. The potential beneficial effect of anticoagulation on outcome is unconvincing in clinical studies, however, and these discrepancies may arise from the multiple and sometimes opposing actions of thrombosis on the pulmonary endothelium following sepsis. It has been suggested, for example, that mild pulmonary thrombosis prevents escape of bacterial infection into the circulation, while severe thrombosis causes hypoxia and results in pulmonary endothelial damage. Evidence from both human and animal studies has demonstrated the key role of microvascular leakage in determining the outcome of sepsis. In this review, we describe thrombosis-dependent mechanisms that regulate pulmonary endothelial injury and repair following sepsis, including activation of the coagulation cascade by tissue factor and stimulation of vascular repair by hypoxia-inducible factors. Targeting such mechanisms through anticoagulant, anti-inflammatory, and reparative methods may represent a novel approach for the treatment of septic patients.