Literature review of distal deep vein thrombosis

OBJECTIVE

Although distal deep vein thrombosis (DDVT) has been more frequently diagnosed with the availability of better ultrasound imaging quality, the data on the best method to manage DDVT have been conflicting. The aim of the present review was to summarize the current and evidence-based recommendations for the diagnosis and management of DDVT and to provide a summary of the most recent societal guideline recommendations.

METHODS

A literature review of DDVT was performed. The PubMed databases were queried for articles on the epidemiology, risk factors, diagnosis, and management of DDVT.

RESULTS

The prevalence of isolated DDVT has been reported in a broad range. The reported risk factors include older age, active malignancy, a low degree of mobility, acute infection, and atrial fibrillation. With more evidence, anticoagulation therapy was found to be associated with a reduced risk of recurrent venous thromboembolism (VTE) and/or thrombus propagation compared with conservative management. However, anticoagulation was associated with an increased risk of bleeding in a number of studies. The rate of VTE recurrence ranged from 7% to 23% during a follow-up period ranging from 3 months to 8 years. The significant risk factors for VTE recurrence included cancer, older age, an unprovoked event, and inpatient status.

CONCLUSIONS

Few studies have addressed the diagnosis and management of DDVT. Further research is needed to standardize the best approach to diagnose and treat DDVT.

Investigation of the Incidence of Perioperative Pulmonary Embolism in Patients with Below-Knee Deep Vein Thrombosis after Lower Extremity Fracture and Evaluation of Retrievable Inferior Vena Cava Filter Deployment in These Patients

BACKGROUND

The objectives of the study were to investigate and compare the incidence of perioperative pulmonary embolism (PE) in trauma patients with below-knee deep vein thrombosis (BKDVT) and above-knee DVT (AKDVT) who need major orthopedic surgery and evaluate the usage of inferior vena cava (IVC) filters in these cases with BKDVT.

METHODS

Between January 2003 and December 2017, patients with pelvic and/or lower extremity fracture diagnosed with DVT by duplex ultrasound were eligible for the study. A reduced-dose anticoagulation therapy was administered in patients without absolute contraindication to anticoagulation therapy during the perioperative period. Patients who did not undergo filter insertion with BKDVT were classified as the BKDVT group, and cases with thrombosis involving the popliteal or more proximal veins were classified as the AKDVT group; the incidence of PE was analyzed. Among patients with BKDVT, cases with or without filter deployment were placed in the filter group and control group, respectively, to evaluate the value of IVC filter in these patients.

RESULTS

A total of 3295 patients with pelvic and/or lower extremity fracture were diagnosed as having DVT, among which, 2070 cases did not undergo filter insertion. The incidence of PE in the BKDVT group and AKDVT group was 2.08% (24/1154) and 3.17% (29/916), respectively. A total of 366 patients with BKDVT underwent filter placement and no PE occurred. The incidence of PE in the filter group was lower than the control group. In patients without filter placement, the cases received anticoagulation therapy and those who did not, the incidence of PE was 2.21% and 1.94%, respectively, and there was no difference between the two subgroups.

CONCLUSIONS

There was no difference in incidence of PE between the AKDVT and BKDVT groups. Reduced-dose anticoagulation therapy does not affect the rates of PE in trauma patients with BKDVT who require ongoing orthopedics operations. For these patients, placement of the retrievable filter may be considered.

Surveillance, anticoagulation, or filter in calf vein thrombosis

OBJECTIVE

This study compared the efficacy and complication rates of inferior vena cava (IVC) filters for calf vein thrombosis (CVT) vs conservative treatment with or without anticoagulation.

METHODS

Vascular laboratory studies of patients who had an isolated CVT (anterior and posterior tibialis, peroneal, soleal, and gastrocnemius veins) from April 2009 to January 2014 were retrospectively analyzed from a single institution. Of 647 patients with isolated CVT, 285 (44%) received an IVC filter, and 362 (56%) received medical treatment alone (38.9% surveillance, 11.6% prophylactic anticoagulation, and 49.4% therapeutic anticoagulation). Univariate, multivariate, propensity matching, and Kaplan-Meier analyses were performed on abstracted data, which included, but was not limited to, risk factors, treatment modalities, venous thromboembolism (VTE) complications (defined as propagation of deep vein thrombosis [DVT] or pulmonary embolism [PE]), bleeding complications, and IVC filter-related complications (ie, filter tilting >15°, perforation >3 mm, fracture, migration >10 mm).

RESULTS

The overall incidence of PE in was 2.5% in the IVC filter group and 3.3% in the medical group (P = .27). The overall incidence of VTE complications (propagation of DVT, PE) was 35% for the surveillance group without anticoagulation, 30% in patients treated with prophylactic anticoagulation, and 10% in patients treated with therapeutic anticoagulation (P = .0003). Only a minority of patients underwent duplex ultrasound imaging after filter insertion. In the IVC filter group, the most common reasons that contraindicated anticoagulation were bleeding (35%) or recent surgery (27%). The number of IVC filter-related complications in the IVC filter group was 29 (10%). Because the IVC filter group was older (mean age, 65 vs 61 years, P = .004) and more likely to have a history of thromboembolic events (56% vs 16%, P < .0001), and malignancy (49% vs 28%, P < .0001), propensity analyses were performed yielding a homogenous cohort. The overall complication and thromboembolic rates did not differ for muscular (soleal, gastrocnemius) vs tibial DVTs (anterior, posterior, peroneal veins).

CONCLUSIONS

The use of anticoagulation in patients with CVT significantly decreases the rates of VTE complications. The use of IVC filters in this study was associated with a 10% complication rate and did not significantly reduce the incidence of PE. Nevertheless, given the overall low rates of PE and the higher risk of VTE in patients who receive filters, the decision to insert a filter in patients with calf CVT should be individualized.

Identifying the factors influencing practice variation in thrombosis medicine: A qualitative content analysis of published practice-pattern surveys

Practice variation, the differences in clinical management between physicians, is one reason why patient outcomes may differ. Identifying factors that contribute to practice variation in areas of clinical uncertainty or equipoise may have implications for understanding and improving patient care. To discern what factors may influence practice variation, we completed a qualitative content analysis of all practice-pattern surveys in thrombosis medicine in the last 10years. Out of 2117 articles screened using a systematic search strategy, 33 practice-pattern surveys met eligibility criteria. Themes were identified using constant comparative analysis of qualitative data. Practice variation was noted in all 33 practice-pattern surveys. Contributing factors to variation included lack of available evidence, lack of clear and specific guideline recommendations, past experience, patient context, institutional culture and the perceived risk and benefit of a particular treatment. Additional themes highlight the value placed on expertise in challenging clinical scenarios, the complexity of practice variation and the value placed on minimizing practice variation.

Emergency Department Management of Suspected Calf-Vein Deep Venous Thrombosis: A Diagnostic Algorithm

Introduction

Unilateral leg swelling with suspicion of deep venous thrombosis (DVT) is a common emergency department (ED) presentation. Proximal DVT (thrombus in the popliteal or femoral veins) can usually be diagnosed and treated at the initial ED encounter. When proximal DVT has been ruled out, isolated calf-vein deep venous thrombosis (IC-DVT) often remains a consideration. The current standard for the diagnosis of IC-DVT is whole-leg vascular duplex ultrasonography (WLUS), a test that is unavailable in many hospitals outside normal business hours. When WLUS is not available from the ED, recommendations for managing suspected IC-DVT vary. The objectives of the study is to use current evidence and recommendations to (1) propose a diagnostic algorithm for IC-DVT when definitive testing (WLUS) is unavailable; and (2) summarize the controversy surrounding IC-DVT treatment.

Discussion

The Figure combines D-dimer testing with serial CUS or a single deferred FLUS for the diagnosis of IC-DVT. Such an algorithm has the potential to safely direct the management of suspected IC-DVT when definitive testing is unavailable. Whether or not to treat diagnosed IC-DVT remains widely debated and awaiting further evidence.

Conclusion

When IC-DVT is not ruled out in the ED, the suggested algorithm, although not prospectively validated by a controlled study, offers an approach to diagnosis that is consistent with current data and recommendations. When IC-DVT is diagnosed, current references suggest that a decision between anticoagulation and continued follow-up outpatient testing can be based on shared decision-making. The risks of proximal progression and life-threatening embolization should be balanced against the generally more benign natural history of such thrombi, and an individual patient’s risk factors for both thrombus propagation and complications of anticoagulation.

Retrospective review on isolated distal deep vein thrombosis (IDDVT) - A benign entity or not?

INTRODUCTION

Isolated distal deep venous thrombosis (IDDVT) is traditionally associated with less severe clinical sequelae, with ongoing debate on multiple aspects of its management. Despite numerous studies evaluating its acute management, there remains a paucity of data evaluating long-term complications such as recurrence and subsequent malignancy. We aim to evaluate the characteristics of IDDVT in institutions that routinely perform whole leg ultrasonography, and the risks of recurrence and complications in comparison to major venous thromboembolism (major VTE; defined as above-knee or proximal DVT and pulmonary embolism (PE)).

METHODS

Retrospective evaluation of consecutive IDDVT and major VTE from July 2011 to December 2012 in a hospital network in Melbourne, Australia. Patients were followed up for a minimum of 24months. Patients with active malignancy were excluded.

RESULTS

Of 1024 VTE cases, there were 164 non-cancer patients (92 males, 72 females, median age of 61years) with IDDVT. Compared to major VTE, IDDVT was more likely to be provoked (73% vs 59%, p<0.01), has shorter duration of anticoagulation (median 3.5months vs 6.0months, p<0.01) and less clinically significant bleeding (2.4% vs 6.7%, p=0.05), independent of duration of therapy. Recurrence was non-inferior compared to major VTE (10% vs 7%, p=0.36) and 60% recurred with major VTE. Three (1.8%) were subsequently diagnosed with cancer (vs 1.9% in major VTE, p=0.97).

CONCLUSIONS

IDDVT has non-inferior rates of recurrence and subsequent cancer detection compared to major VTE and hence, its clinical significance should not differ from major VTE. Further studies are required to determine the adequate length of anticoagulation.