Proximal and isolated distal deep vein thrombosis and Wells score accuracy in hospitalized patients

Bilateral lower limb examinations for deep vein thrombosis: A single-centre pilot study comparing request and report parameters for bilateral and unilateral referrals

INTRODUCTION

Deep vein thrombosis (DVT) is a common pathology with significant morbidity and mortality, often occurring in the lower limb. Ultrasound is the modality of choice for diagnosis of DVT, but all guidance in the United Kingdom assumes a single leg referral. Few studies have addressed the question of bilateral referrals and bilateral DVTs, and it is not known how these should be included in ultrasound protocols. This study aims to compare the request and report parameters of bilateral examinations with those for single leg examinations over a six-month period.

METHODS

A single-centre feasibility study collected data on all single and bilateral leg examinations performed by sonographers, over a six-month period at a small general hospital. Data collected for each examination included the referral and report findings. These were compared using basic statistical methods to compare DVT yield by laterality, referrer, DVT site, and patient factors.

RESULTS

Six hundred and thirty examinations were included, eighteen of which were bilateral examinations. Although the bilateral leg cohort was small, there were significant differences in DVT yield between the groups, with single leg referrals more than eight times more likely to demonstrate a DVT at ultrasound.

CONCLUSION

In a context of limited ultrasound resource, the low DVT yield of bilateral examinations has implications for service design. Further data collection will be needed to validate initial results, and to establish suitable criteria for acceptance of bilateral DVT referrals.

IMPLICATIONS FOR PRACTICE

Low yield of DVTs in bilateral examinations can be validated via further research. Bilateral examinations can be explicitly included in DVT service design.

Diagnostic value of D-dimer for lower extremity deep venous thrombosis caused by rib fracture: a retrospective study

OBJECTIVE

This study aimed to investigate the role of D-dimer in the diagnosis of lower extremity deep venous thrombosis (DVT) in patients with rib fractures.

METHOD

Retrospective analysis was conducted on the clinical data of 499 patients with rib fractures who were admitted to the Third Hospital of Shijiazhuang between October 2020 and September 2021. These patients were divided into the DVT and the non-DVT groups. D-dimer levels were compared between the two groups at 24, 48, and 72 h after the injury. Receiver operating characteristic curves were utilized to evaluate the diagnostic efficacy of dynamically monitoring changes in D-dimer for DVT.

RESULTS

The D-dimer levels in the DVT group were significantly higher than those in the non-DVT group at 24, 48, and 72 h after the injury. The area under the curve values for predicting DVT based on D-dimer level at 24, 48, and 72 h after injury in patients with rib fractures were 0.788, 0.605, and 0.568, respectively.

CONCLUSION

Detecting D-dimer levels 24 h after the injury can enhance diagnostic efficacy and sensitivity for DVT, thereby reducing the rate of missed diagnoses, which is of great clinical value.

Development and validation of a predictive nomogram for lower extremity deep vein thrombosis dislodgement in orthopedic patients

Objective

To analyze the risk factors of lower extremity deep venous thrombosis (DVT) detachment in orthopedic patients, and to establish a risk nomogram prediction model.

Methods

The clinical data of 334 patients with orthopedic DVT admitted to the Third Hospital of Hebei Medical University from January 2020 to July 2021 were retrospectively analyzed. General statistics included gender, age, BMI, thrombus detachment, inferior vena cava filter window type, filter implantation time, medical history, trauma history, operation, use of tourniquet, thrombectomy, anesthesia mode, anesthesia grade, operative position, blood loss during operation, blood transfusion, immobilization, use of anticoagulants, thrombus side, thrombus range, D-dimer content before filter implantation and during removal of inferior vena cava filter. Logistic regression was used to perform univariate and multivariate analysis on the possible factors of thrombosis detachment, screen out independent risk factors, establish a risk nomogram prediction model by variables, and internally verify the predictability and accuracy of the model.

Results

Binary logistic regression analysis showed that Short time window filter (OR = 5.401, 95% CI = 2.338–12.478), lower extremity operation (OR = 3.565, 95% CI = 1.553–8.184), use of tourniquet (OR = 3.871, 95% CI = 1.733–8.651), non-strict immobilization (OR = 3.207, 95% CI = 1.387–7.413), non-standardized anticoagulation (OR = 4.406, 95% CI = 1.868–10.390), distal deep vein thrombosis (OR = 2.212, 95% CI = 1.047–4.671) were independent risk factors for lower extremity DVT detachment in orthopedic patients (P < 0.05). Based on these six factors, a prediction model for the risk of lower extremity DVT detachment in orthopedic patients was established, and the risk prediction ability of the model was verified. The C-index of the nomogram model was 0.870 (95% CI: 0.822–0.919). The results indicate that the risk nomogram model has good accuracy in predicting the loss of deep venous thrombosis in orthopedic patients.

Conclusion

The nomogram risk prediction model based on six clinical factors, including filter window type, operation condition, tourniquet use, braking condition, anticoagulation condition, and thrombosis range, has good predictive performance.

'Current trends in lower limb Doppler scanning in Ireland'

INTRODUCTION

The clinical need to diagnose and treat above knee deep vein thrombosis (AKDVT) has long been established in literature and in practice. On the other hand, the need to diagnose and treat below knee deep vein thrombosis (BKDVT) continues to be debated in literature. This has resulted in variation in clinical guidelines and protocols nationwide. This research aims to establish if there is a standard practice in Irish ultrasound departments and if so, what that practice is and where sonographers are getting information to inform this.

METHODS

A questionnaire was designed using SurveyMonkey and distributed using online platforms. The questionnaire aimed to establish the experience of the sonographer, the types of exams performed, protocols/guidelines used as well as scenarios where the sonographer might deviate from protocol.

RESULTS

The study yielded 90 responses. The research found 49% of sites perform whole leg ultrasound routinely and 46% perform proximal ultrasound only. 41% of respondents said their protocols were based on clinical guidelines however, 22% of participants didn't know what these guidelines were. 49% of respondents were unaware of what treatment a patient would receive in cases where there is a high clinical suspicion of DVT, but the ultrasound is negative for DVT.

CONCLUSION

The research has established a lack of consistency amongst sonographers and scanning practices with a fairly even split (49% of respondents perform whole leg ultrasound and 46% perform proximal only). Not only has the research identified a lack of standardised scanning approach nationwide, but inconsistencies are also seen in the guidelines that inform our department's protocols as well as inconspicuous terms used in radiology reporting and jargon in literature in relation to DVT.

IMPLICATIONS FOR PRACTICE

1. An inconsistency in practice has been established. Discussions are now needed to decide what guidelines should be implemented into Irish Ultrasound DVT protocols. 2. A national protocol for BKDVT would result in all patients in Ireland having access to the same standard of care. 3. Call for consensus on appropriate training for sonographers undertaking LLDs.

Clinical presentation of isolated calf deep vein thrombosis in inpatients and prevalence of associated pulmonary embolism

OBJECTIVE

There is a controversy over the clinical significance and optimal treatment for isolated calf DVT. This study aimed to investigate the clinical presentation of isolated calf deep vein thrombosis (DVT) and the association of isolated calf DVT with pulmonary embolism (PE) in inpatients.

METHODS

A total of 1435 hospitalized patients underwent whole-leg duplex ultrasound between January 2018 and June 2020. Among them, 135 were diagnosed with isolated calf vein DVT.

RESULTS

The soleal vein was the most frequently involved (52.6%). Thrombus was detected only in axial veins in 57 patients (42.2%), muscular veins in 46 patients (34.4%), and in both axial and muscular veins in 32 patients (23.7%). Of the 135 patients, 44 patients (32.6%) had underwent recent orthopedic surgery, 31 patients (23.0%) had active cancer, and 22 patients (16.3%) had a history of recent stroke. The reasons for duplex ultrasound were leg edema and/or pain in 57 patients (42.2%), diagnosis of PE in 33 (24.4%), and elevated D-dimer level in 27 patients (20.0%). Sixteen patients (11.9%) were diagnosed as incidental findings on imaging studies for other purposes. Ninety-six patients (71.1%) received anticoagulation therapy. Concurrent PE was diagnosed in 45 patients (33.3%) and 14 patients had lesions in the main pulmonary artery. Among 45 patients with concurrent PE, 35 patients were diagnosed without leg edema and/or pain. Recurrent VTE was observed in four patients (3.0%) with a mean follow-up of 15.5±12.7 months.

CONCLUSIONS

Isolated calf DVT was associated with a high prevalence of PE in hospitalized patients. Patients with isolated calf DVT even without leg edema and/or pain may have concurrent PE. Anticoagulation therapy should be considered for isolated calf DVT in inpatients. The muscular veins were frequently involved, thus should be thoroughly evaluated and imaged.

Meta-analysis and systematic review of randomized controlled trials assessing the role of thromboprophylaxis after vascular surgery

BACKGROUND

Venous thromboembolism (VTE) is a well-known complication associated with surgical procedures. The implementation of thromboprophylaxis in this population has become a vital aspect of perioperative care to decrease VTE-associated morbidity and mortality risk. However, data assessing the role of thromboprophylaxis for patients undergoing vascular surgery are sparse. Assessing the role of thromboprophylaxis by low-molecular-weight heparin or unfractionated heparin in vascular surgery.

METHODS

We searched MEDLINE, Embase, and the Cochrane Collaboration Central Register of Controlled Trials from inception until December 2020, for randomized controlled trials assessing the role of thromboprophylaxis in vascular surgery.

RESULTS

Eight randomized controlled trials met inclusion criteria, including 3130 patients, with a mean age of 55.35 years and 45% were females. Compared with placebo, anticoagulant use was associated with a decrease in deep venous thrombosis (DVT) (risk ratio [RR], 0.34; 95% confidence interval [CI], 0.11-1.05; P = .06; I² = 68%) and pulmonary embolism (PE) (RR, 0.17; 95% CI, 0.02-1.22; P = .08; I² = 41%), but this trend did not attain statistical significance. There was no difference for bleeding outcomes between anticoagulants and placebo (RR, 0.90; 95% CI, 0.05-15.01; P = .94; I² = 76%). There was no significant difference in outcomes when low-molecular-weight heparin was compared directly with unfractionated heparin. In a sensitivity analysis, anticoagulant use was associated with a significant decrease in DVT or PE in patients undergoing venous surgeries, but was not associated with a significant decrease in DVT or PE in patients undergoing arterial surgeries, although this analysis was limited by the small number of studies in each group.

CONCLUSIONS

Among patients undergoing vascular surgery, thromboprophylaxis with anticoagulants showed a trend toward a lesser incidence of VTE when compared with placebo, although this difference was not statistically significant. Bleeding outcomes were comparable between both treatment groups.

Relevance of immobility as a risk factor for symptomatic proximal and isolated distal deep vein thrombosis in acutely ill medical inpatients

Immobility is a well-recognized risk factor for deep vein thrombosis (DVT) in surgical patients, whereas the level of DVT risk conferred by immobility is less defined in patients on medical wards. The aim of this study was to establish whether immobility and its duration are associated with the risk of DVT in acutely ill medical inpatients. We conducted a cohort study in acutely ill medical inpatients. Patients underwent whole leg ultrasound for suspected lower extremity DVT and were divided into two groups according to presence or absence of immobility, defined as total bed rest or sedentary without bathroom privileges. The endpoint was the detection of proximal DVT or isolated distal DVT (IDDVT). Among the 252 acutely ill medical inpatients with immobility (age 82.6 ± 10.3 years, female 63.9%), ultrasound showed 36 (14.3%) proximal DVTs and 39 (15.5%) IDDVTs, while there were 11 (4.4%) proximal DVTs and 26 (10.5%) IDDVTs among the 248 inpatients without immobility (age 73.6 ± 14.2 years, female 54.8%). The risk of proximal DVT was higher in immobile than in mobile patients (OR 3.59, 95% CI: 1.78-7.23, p = 0.0001), whereas the risk of IDDVT was similar between the two groups (OR 1.56, 95% CI: 0.92-2.66, p = 0.111). During the first 3 days of hospitalization, the frequency of all DVTs was similar in patients with and without immobility, but it was 0.26 ± 0.03 vs 0.18 ± 0.03, respectively, after 4 days. In conclusion, immobility for more than 3 days is a risk factor for proximal DVT in acutely ill medical inpatients.

Performance of the Wells score in predicting deep vein thrombosis in medical and surgical hospitalized patients with or without thromboprophylaxis: The R-WITT study

The Wells score had shown weak performance to determine pre-test probability of deep vein thrombosis (DVT) for inpatients. So, we evaluated the impact of thromboprophylaxis on the utility of the Wells score for risk stratification of inpatients with suspected DVT. This bicentric cross-sectional study from February 1, 2018 to January 31, 2019 included consecutive medical and surgical inpatients who underwent lower limb ultrasound study for suspected DVT. Wells score clinical predictors were assessed by both ordering and vascular physicians within 24 h after clinical suspicion of DVT. Primary outcome was the Wells score's accuracy for pre-test risk stratification of suspected DVT, accounting for anticoagulation (AC) treatment (thromboprophylaxis for ⩾ 72 hours or long-term anticoagulation). We compared prevalence of proximal DVT among the low, moderate and high pre-test probability groups. The discrimination accuracy was defined as area under the receiver operating characteristics (ROC) curve. Of the 415 included patients, 30 (7.2%) had proximal DVT. Prevalence of proximal DVT was lower than expected in all pre-test probability groups. The prevalence in low, moderate and high pre-test probability groups was 0.0%, 3.1% and 8.2% (p = 0.22) and 1.7%, 4.2% and 25.8% (p < 0.001) for inpatients with or without AC, respectively. Area under ROC curves for discriminatory accuracy of the Wells score, for risk of proximal DVT with or without AC, was 0.72 and 0.88, respectively. The Wells score performed poorly for discrimination of risk for proximal DVT in hospitalized patients with AC but performed reasonably well among patients without AC; and showed low inter-rater reliability between physicians. ClinicalTrials.gov Identifier: NCT03784937.

The anatomic distribution and pulmonary embolism complications of hospital-acquired lower extremity deep venous thrombosis

OBJECTIVE

The anatomic distribution of lower extremity deep venous thrombosis (LEDVT) plays an important role in its prevention and treatment. This study aimed to evaluate the anatomic distribution of hospital-acquired LEDVT (HA-LEDVT) and its probable role in the occurrence of pulmonary embolism (PE).

METHODS

We retrospectively analyzed the demographic data, ultrasound results, and PE-related findings of inpatients with HA-LEDVT in 28 clinical departments at Peking University People's Hospital between January 1, 2007, and December 31, 2018.

RESULTS

This study included 1431 HA-LEDVT events: 35.8%, 31%, and 33.3% were left, right, and bilateral LEDVT. Isolated distal, proximal, and blended DVT were detected in 83.4%, 7.3%, and 9.3% of the patients, respectively. The distribution of HA-LEDVT in the left and right lower extremities were not significantly different except in patients aged ≥40 years (left: 2.07 vs right: 1.88 per 1000 extremities, P = .04). For anatomic types of HA-LEDVT, isolated distal HA-LEDVT was 5.02 times more prevalent than proximal HA-LEDVT (1.24 vs 0.26 per 1000 extremities, P ＜ .01). The involvement rates of specific deep veins by HA-LEDVT were highest in the muscular calf vein (87.5%) followed by the popliteal vein (10.1%), superficial femoral vein (9.3%), and common femoral vein (9.2%). HA-LEDVT involving multiple vein segments simultaneously occurred in 338 extremities. HA-LEDVT involving the muscular calf vein and at least one of three connected axial veins of the muscular calf vein occurred most frequently. Eighty-eight patients with HA-LEDVT (6.15%) had PE. The frequency of PE among patients with proximal and distal DVT (7.89% vs 6.23% P = .275) was not significantly different. The incidence of PE was highest in patients with bilateral proximal DVT (15.4%) and lowest in patients with a single right distal DVT (4.5%). PE occurred in 6% of muscular calf vein HA-LEDVT. In isolated muscular calf vein DVT cases, PE were more likely to occur in cases with a ＞6.05-mm-diameter thrombus than in those with a ＜6.05-mm-diameter thrombus (10.3% vs 4.2%, P ＜ .0001).

CONCLUSIONS

HA-LEDVT is characterized by a significantly high percentage of DVT in the muscular calf vein. Muscular calf vein thrombosis may be the primary origin of lower extremity deep vein thrombosis. The diameter of the thrombus in the muscular calf vein may be associated with the occurrence of PE. More prospective studies are needed to more fully determine the natural history of HA-LEDVT and develop prevention and treatment guidelines for HA-LEDVT.

Thromboprophylaxis for orthopedic surgery; An updated meta-analysis

BACKGROUND

Venous thromboembolism (VTE) is a serious complication of orthopedic surgery. Low molecular weight heparin (LMWH) has been the standard of care for thromboprophylaxis in this population. However, direct oral anticoagulants (DOACs) are increasingly being used as alternatives.

OBJECTIVE

To assess the efficacy and safety of DOACs versus LMWH for thromboprophylaxis in orthopedic surgery.

METHODS

We searched MEDLINE, Embase, and the Cochrane Collaboration Central Register of Controlled Trials from inception until April 2020, for randomized controlled trials (RCTs) comparing DOACs with LMWH for thromboprophylaxis in orthopedic surgery.

RESULTS

Twenty-five RCTs met inclusion criteria, including 40,438 patients, with a mean age of 68 years and 50% were males. Compared to LMWH, DOACs were associated with a significant reduction of major VTE; defined as the composite events of proximal deep vein thrombosis (DVT), pulmonary embolism (PE), and VTE-related mortality (RR 0.33; 95% CI: 0.20-0.53; P<0.01), and total DVT (RR: 0.59; 95% CI: 0.48-0.73; P<0.01), but not PE (RR 0.81; 95% CI: 0.49-1.34; P=0.42). There was no statistically significant difference between both groups on the incidence of major bleeding (RR 0.99; 95% CI: 0.77-1.27; P=0.92), clinically relevant non-major bleeding (RR 1.04; 95% CI: 0.92-1.17; P=0.52), all-cause mortality (RR 1.06; 95% CI: 0.64-1.76; P=0.83), VTE-related mortality (RR 0.84; 95% CI: 0.40-1.74; P=0.64) and bleeding-related mortality (RR 1.24; 95% CI: 0.30-5.18; P=0.77).

CONCLUSION

For patients undergoing orthopedic surgery, thromboprophylaxis with DOACs is associated with a significant reduction of major VTE and DVT, compared to LMWH. Safety outcomes were not significantly different between both treatment groups.

Calf deep vein thrombosis: frequency, therapeutic management, early outcomes and all-causes mortality in a cohort of hospitalized patients

BACKGROUND

Isolated distal deep vein thromboses (IDDVT) are frequent; however, their optimal management is still controversial.

METHODS

We performed a retrospective study on inpatients undergoing ultrasound for suspected deep vein thrombosis (DVT) or with a particular risk profile, during 2016. This study aimed to assess the frequency of proximal deep vein thromboses (PDVT) and IDDVT; to evaluate therapeutic management and identify variables associated with early outcomes and mortality among IDDVT patients; to compare all-causes mortality between subjects with PDVT and IDDVT.

RESULTS

Among 21594 patients hospitalized in the study period 251 IDDVT and 149 PDVT were diagnosed; the frequency was 1.2% and 0.7% respectively. 19% of IDDVT patients died compared to 25.5% of PDVT subjects (OR=0.72; 95% CI=0.44-1.17; P=0.19). In IDDVT patients, age ≥80, cancer and intracranial bleeding increased the risk of death (OR=2; 95% CI=1.07-3.75, P=0.001; OR=8.47; 95% CI=3.28-21.88, P=0.0000003; OR=2.33; 95% CI=1.18-4.58, P=0.0003). A significant association between intracranial hemorrhage and both proximal extension by using the Fisher's exact test (P=0.031; OR=16.11; 95% CI=0.80-321.2), and composite of propagation to popliteal or to other calf veins (OR=8.28, 95% CI=2.07-33 P=0.001) was observed. Standard anticoagulation significantly reduced the composite of propagation to popliteal or to other calf veins (OR=0.07; 95% CI=0.009-0.61, P=0.007), and all-causes mortality (OR=0.37; 95% CI=0.17-0.8; P=0.02), without a significant increase of bleeding.

CONCLUSIONS

Among inpatients, IDDVT exceeded 60% of DVT. Mortality was not significantly different between IDDVT and PDVT subjects. Intracranial bleeding significantly increased the risk of propagation and death. Although standard anticoagulation decreased both these complications, further targeted studies are needed.

Calf deep vein thrombosis – clinical relevance, diagnostic approaches and therapeutic options

Summary. Isolated distal deep vein thromboses (IDDVT) represent up to 50 % of legs deep vein thromboses (DVT). However, since their natural history is to date unknown, the need to diagnose and treat them is a matter of debate. The diagnostic strategy based on the assessment of pre-test probability and D-dimer demonstrated a scarse efficiency for IDDVT. The choice between a proximal and a complete ultrasonographic approach should be guided by the clinical context, the local expertise and the patient characteristics. Randomized and observational studies have analyzed the need of therapy and compared different regimens of anticoagulation, with conflicting results. Systematic reviews and meta-analyses tend to support the usefulness of an anticoagulant treatment, even if the optimal dose and duration are not still defined. A careful stratification of the patient’s profile, taking into account risk factors for proximal extension, recurrence and bleeding should address the therapeutic approach, which must always be discussed with an adequately informed patient. Further studies aimed to clarify the natural history of IDDVT, and to assess safety and efficacy of lower intensity and shorter duration protocols are urgently needed.

Diagnosis of deep vein thrombosis

Deep vein thrombosis (DVT) is part of the clinical spectrum of venous thromboembolism disease (VTE), whose estimated annual incidence rate is 1-2 episodes per 1000 individuals and represents the third leading cause of cardiovascular mortality in developed countries. Establishing an accurate diagnosis of DVT is essential for preventing acute complications (such as pulmonary embolism) and chronic complications associated with post-thrombotic syndrome. Currently, there are well-established diagnostic algorithms for lower extremity DVT, which include clinical probability models that help establish the risk of experiencing the disease based on the patients' history, clinical findings, D dimer measurements, fibrin degradation product tests with a high negative predictive value and imaging tests to confirm the diagnosis. Venous compression ultrasonography is currently the technique of choice because it is a non-invasive, easy-to-administer test that can make serial evaluations. There is much accumulated evidence that DVT can be safely ruled out in patients with a low or intermediate clinical probability and a negative D dimer (<500 ng/mL) without performing additional examinations. The consensus is not as clear about the need for a proximal or complete examination of the entire extremity. Other techniques may also be employed, such as magnetic resonance venography and venous phase computed axial tomography, although these should not be a substitute for compression ultrasonography as the initial diagnostic test. There are other special circumstances in which the diagnosis is more problematic and there are no diagnostic algorithms as consolidated, such as DVT during pregnancy, diagnosing rethrombosis and DVT that affects the upper extremities.