Epidemiology of acute deep vein thrombosis

Validation of a pulmonary embolism risk assessment model in gynecological inpatients : Clinical trial: A single-center, retrospective study

OBJECTIVE

To compare the predictive efficacy of the PADUA and Caprini models for pulmonary embolism (PE) in gynecological inpatients, analyze the risk factors for PE, and validate whether both models can effectively predict mortality rates.

METHODS

A total of 355 gynecological inpatients who underwent computed tomography pulmonary angiography (CTPA) were included in the retrospective analysis. The comparative assessment of the predictive capabilities for PE between the PADUA and Caprini was carried out using receiver operating characteristic (ROC) curves. Logistic regression analysis was used to identify risk factors associated with PE. Additionally, Kaplan-Meier survival analysis plots were generated to validate the predictive efficacy for mortality rates.

RESULTS

Among 355 patients, the PADUA and Caprini demonstrated the area under the curve (AUC) values of 0.757 and 0.756, respectively. There was no statistically significant difference in the AUC between the two models (P = 0.9542). Multivariate logistic analysis revealed immobility (P < 0.001), history of venous thromboembolism (VTE) (P = 0.002), thrombophilia (P < 0.001), hormonal treatment (P = 0.022), and obesity (P = 0.019) as independent risk factors for PE. Kaplan-Meier survival analysis demonstrated the reliable predictive efficacy of both the Caprini (P = 0.00051) and PADUA (P = 0.00031) for mortality. ROC for the three- and six-month follow-ups suggested that the Caprini model exhibited superior predictive efficacy for mortality.

CONCLUSIONS

The PADUA model can serve as a simple and effective tool for stratifying high-risk gynecological inpatients before undergoing CTPA. The Caprini model demonstrated superior predictive efficacy for mortality rates.

Point-of-care ultrasound: impact on emergency department length of stay for suspected lower extremity DVT

BACKGROUND

Point-of-care ultrasound (POCUS) has demonstrated excellent sensitivity and specificity for the diagnosis of DVT in the emergency department (ED). Before POCUS became widespread, patients underwent radiology department comprehensive lower extremity venous duplex ultrasounds (RADUS) which may be associated with a prolonged length of stay.

OBJECTIVES

The goal of this study is to evaluate the impact of POCUS on ED arrival to disposition (ATD) time for patients presenting to the ED with suspected lower extremity DVT.

METHODS

This is a retrospective chart analysis of ED visits to an urban, university-affiliated community hospital from January 2019 to December 2020. This study compared ATD between patients who underwent POCUS by an emergency medicine physician and RADUS by the radiology department.

RESULTS

In total, 1204 patients underwent POCUS, and 1582 patients were evaluated with RADUS. The POCUS mean ATD was 313 ± 16.8 min compared to the RADUS arm average of 323 ± 57.9 min (p = 0.56). Order to disposition time (OTD) was prolonged among the RADUS group relative to POCUS. ATD was significantly reduced in the POCUS subgroup of patients presenting during night shift when RADUS was not available, 326 ± 28.2 min versus 630 ± 109 min (p < 0.05).

CONCLUSION

ED POCUS scans decrease the amount of time between order placement and disposition when compared to RADUS. POCUS significantly decreases length of stay in the ED when RADUS is not available.

Does COVID-19 infection increase the risk of pulmonary embolism in ambulatory patients with deep vein thrombosis

OBJECTIVES

Coronavirus disease 2019 (COVID-19) can lead to systemic coagulation activation and thrombotic complications including venous thromboembolism. This study compares the development of pulmonary embolism, post-thrombotic syndrome, and clinical outcomes of COVID-19 and non-COVID-19 patients with deep vein thrombosis (DVT).

METHODS

One hundred and eight patients diagnosed with acute deep vein thrombosis (DVT) between June 2020 and February 2021 in our institution were included in this retrospective study. Thirty-nine patients had been previously diagnosed with COVID-19 and specified as the COVID-19 group. Sixty-nine patients did not have COVID-19 and specified as the non-COVID-19 group. Mean ages of both groups were 64.3 ± 15.8 and 60.1 ± 19.7 years, respectively (p = .37).

RESULTS

The median duration from the onset of the COVID-19 to diagnosis of DVT was 22 (2-120) days in the COVID-19 group. The patients of two groups were mostly treated outpatient at rates of 94.9% vs 94.2%, respectively (p = .88). Pulmonary embolism was seen in six patients (15.4%) in the COVID-19 group and in three patients (4.3%) in the non-COVID-19 group (p = .04). Kaplan-Meir curves showed that patients with COVİD-19 had significantly higher pulmonary embolism than those without COVID-19 (p = .015). The recurrence rate of DVT was 2.6% in the COVID-19 group (n = 1), and 4.3% in the non-COVID-19 group (n = 3), indicating no statistically significant difference (p = .63). Mortality was seen in six patients (15.4%) in the COVİD-19 group, and in seven patients (10.1%) in the non-COVID-19 group. According to the Kaplan-Meir method, 10 months survival rates were 73.9 ± 10% in the COVID-19 group, and 66.3 ± 12.8% in the non-COVID-19 group with no statistical significance (p = .218).

CONCLUSIONS

Our data draw attention to the fact that deep vein thrombosis should not be considered a safe and self-limited condition. Efficient preventive measures such as mobilization and prophylactic drug use should be considered to prevent DVT during the management of COVID-19.

Catheter-Directed Interventions for the Treatment of Lower Extremity Deep Vein Thrombosis

Lower extremity deep vein thrombosis (DVT) leads to significant morbidity including pain, swelling, and difficulty walking in the affected limb. If left untreated, DVT increases the risk of pulmonary embolism (PE), recurrent venous thromboembolism (VTE), and post thrombotic syndrome (PTS). The objective of this review was to identify catheter-directed interventions and their success rates for the treatment of lower extremity DVT. A comprehensive search of current and emerging catheter-directed interventions for lower extremity DVT treatment was conducted in PubMed and Google Scholar. Clinical trials, retrospective and prospective observational studies, and case reports were identified to classify percutaneous mechanical thrombectomy (PMT), catheter-directed thrombolysis (CDT), and pharmacomechanical CDT (PCDT) devices based on their mechanism of action and indication of use. Catheter-directed interventions such as PMT, CDT, and PCDT offer an alternative therapeutic strategy for DVT management, particularly in patients with limb-threatening conditions and absolute contraindications to anticoagulants. Currently, there are limited guidelines for the use of mechanical and pharmacomechanical devices because of the lack of clinical evidence available for their use in treatment. Future studies are required to determine the short and long-term effects of using catheter-directed interventions as well as their effectiveness in treating acute versus subacute and chronic DVT.

Evaluation of the diagnostic management of deep vein thrombosis in the emergency department of a tertiary hospital in Santa Catarina, Brazil: a cross-sectional study

Background

Venous thromboembolism is an entity that encompasses both deep vein thrombosis and pulmonary thromboembolism. Although protocols for the diagnosis of these diseases are well defined, there is evidence of inappropriate use of diagnostic resources.

Objectives

To define the epidemiological profiles of patients admitted to the emergency department with suspected deep vein thrombosis, to determine rates of inappropriate ordering of D-dimer assays and color venous Doppler echocardiography of the lower limbs, and to identify whether these requests followed the recommendations contained in the 2015 Brazilian Society of Angiology and Vascular Surgery guidelines.

Methods

We conducted a cross-sectional observational study that retrospectively evaluated 168 patients with suspected deep vein thrombosis for whom D-dimer assays were requested. The most common risk factors were measured and the pretest probability was calculated with the Wells score. The epidemiological profile of these patients and the rates of inappropriate D-dimer testing were assessed using descriptive statistics.

Results

The D-dimer requests were inadequate in 55 (32.7%) patients. Venous color Doppler ultrasound was used to examine the lower limbs of 14 (8.3%) of the patients with a low probability according to the Wells score and a negative D-dimer result. No additional diagnostic methods were used in 19 (11.3%) of those with a low probability according to the Wells score and a high D-dimer result. There was unnecessary use of CDUS in 35 (20.8%) cases. The overall rate of inappropriate workup was 53.5%.

Conclusions

Differences were found between clinical practice and the recommendations for diagnostic evaluation of patients with suspected deep vein thrombosis, with inappropriate use of diagnostic tests.

Optimal preoperative timing for prevention of deep vein thrombosis (DVT) in patients over 60 years of age with intertrochanteric fractures

PURPOSE

To investigate the incidence and risk factors of preoperative DVT in elderly patients with intertrochanteric fracture of the femur and determine the optimal preoperative time.

METHODS

Electronic medical records of 358 patients over 60 years of age with intertrochanteric fractures from May 1, 2016, to May 1, 2019, were retrospectively analyzed. The preoperative group was divided into DVT and non-DVT. Univariate analysis was used for preliminary comparison, and multivariate logistic regression analysis was used to identify independent risk factors associated with DVT development. ROC curve was drawn to analyze the specificity and sensitivity of risk factors for DVT diagnosis. The diagnostic value of the model was analyzed by the ROC curve of multivariable combined diagnosis.

RESULTS

A total of 358 patients who met the criteria were enrolled. The total prevalence of DVT before surgery was 8.38%. Multivariate logistic regression analysis showed that smoking status, preoperative time, albumin (ALB), D-dimer level, diabetes mellitus, and hypertension were independent risk factors for preoperative DVT. Preoperative time has the best sensitivity and specificity for diagnosing the occurrence of preoperative DVT. The ROC curve analysis model of multivariable combined diagnosis has a better diagnostic value.

CONCLUSIONS

In this study, elderly patients with intertrochanteric femur fracture had a higher incidence of deep vein thrombosis before surgery. Early identification of DVT-related risk factors may contribute to individualized risk assessment and preventing adverse outcomes in patients with intertrochanteric fractures.

Deep thrombosis characterization using photoacoustic imaging with intravascular light delivery

Venous thromboembolism (VTE) is a condition in which blood clots form within the deep veins of the leg or pelvis to cause deep vein thrombosis. The optimal treatment of VTE is determined by thrombus properties such as the age, size, and chemical composition of the blood clots. The thrombus properties can be readily evaluated by using photoacoustic computed tomography (PACT), a hybrid imaging modality that combines the rich contrast of optical imaging and deep penetration of ultrasound imaging. With inherent sensitivity to endogenous chromophores such as hemoglobin, multispectral PACT can provide composition information and oxygenation level in the clots. However, conventional PACT of clots relies on external light illumination, which provides limited penetration depth due to strong optical scattering of intervening tissue. In our study, this depth limitation is overcome by using intravascular light delivery with a thin optical fiber. To demonstrate in vitro blood clot characterization, clots with different acuteness and oxygenation levels were placed underneath ten-centimeter-thick chicken breast tissue and imaged using multiple wavelengths. Acoustic frequency analysis was performed on the received PA channel signals, and oxygenation level was estimated using multispectral linear spectral unmixing. The results show that, with intravascular light delivery, clot oxygenation level can be accurately measured, and the clot age can thus be estimated. In addition, we found that retracted and unretracted clots had different acoustic frequency spectrum. While unretracted clots had stronger high frequency components, retracted clots had much higher low frequency components due to densely packed red blood cells. The PACT characterization of the clots was consistent with the histology results and mechanical tests.

Evaluation of the diagnostic management of deep vein thrombosis in the emergency department of a tertiary hospital in Santa Catarina, Brazil: a cross-sectional study

Abstract Background Venous thromboembolism is an entity that encompasses both deep vein thrombosis and pulmonary thromboembolism. Although protocols for the diagnosis of these diseases are well defined, there is evidence of inappropriate use of diagnostic resources. Objectives To define the epidemiological profiles of patients admitted to the emergency department with suspected deep vein thrombosis, to determine rates of inappropriate ordering of D-dimer assays and color venous Doppler echocardiography of the lower limbs, and to identify whether these requests followed the recommendations contained in the 2015 Brazilian Society of Angiology and Vascular Surgery guidelines. Methods We conducted a cross-sectional observational study that retrospectively evaluated 168 patients with suspected deep vein thrombosis for whom D-dimer assays were requested. The most common risk factors were measured and the pretest probability was calculated with the Wells score. The epidemiological profile of these patients and the rates of inappropriate D-dimer testing were assessed using descriptive statistics. Results The D-dimer requests were inadequate in 55 (32.7%) patients. Venous color Doppler ultrasound was used to examine the lower limbs of 14 (8.3%) of the patients with a low probability according to the Wells score and a negative D-dimer result. No additional diagnostic methods were used in 19 (11.3%) of those with a low probability according to the Wells score and a high D-dimer result. There was unnecessary use of CDUS in 35 (20.8%) cases. The overall rate of inappropriate workup was 53.5%. Conclusions Differences were found between clinical practice and the recommendations for diagnostic evaluation of patients with suspected deep vein thrombosis, with inappropriate use of diagnostic tests.

Magneto-sonothrombolysis with combination of magnetic microbubbles and nanodroplets

This paper reports a novel technique using the rotational magnetic field oscillation and low-intensity sub-megahertz ultrasound stimulation of magnetic microbubbles (MMBs) to promote the nanodroplets (NDs) phase transition and improve the permeation of NDs into the blood clot fibrin network to enhance the sonothrombolysis efficiency. In this study, the influence of different treatment methods with a combination of MMBs and NDs on the thrombolysis rate of both unretracted and retracted clots were investigated, including the stable and inertial cavitation, tPA effects, MMBs/NDs concentration ratio, sonication factors (input voltage, duty cycle) and rotational magnetic field factors (flux density, frequency). We demonstrated that tPA-mediated magneto-sonothrombolysis in combining NDs with MMBs could significantly enhance in vitro lysis of both unretracted clots (85 ± 8.3%) and retracted clots (57 ± 6.5%) in a flow model with 30 min treatment. The results showed that the combination of MMBs and NDs substantially improves in vitro lysis of blood clots with an unprecedented lysis rate.

Evaluation of Deep Vein Thrombosis Risk Factors After Arthroscopic Posterior Cruciate Ligament Reconstruction: A Retrospective Observational Study

We evaluated the risk factors of deep venous thrombosis (DVT) after knee arthroscopic posterior cruciate ligament (PCL) reconstruction in patients with only PCL injury. From August 2014 to December 2020, a total of 172 patients who had accepted knee arthroscopic PCL reconstruction underwent the color Doppler ultrasound of bilateral lower-extremities deep veins on 3 days postoperatively. Based on the inspection results, patients were divided into DVT group (18 males and 8 females, mean age 43.62 years) and non-DVT group (108 males and 38 females, mean age 33.96 years). The potential associations of DVT risk and age, gender, body mass index (BMI), diabetes, hypertension, smoking and other factors were analyzed. An old age (OR = 1.090; 95% CI = 1.025-1.158; P = 0.006), a high BMI (OR = 1.509; 95% CI = 1.181-1.929; P = 0.001) and an increased post-surgery D-dimer (OR = 5.034; 95% CI = 2.091-12,117; P ≤ 0.001) value were significantly associated with an elevated DVT risk after knee arthroscopic PCL reconstruction. Increased age, BMI, and postoperative D-dimer were risk factors of DVT following knee arthroscopic PCL reconstruction in patients with only PCL injury.

Chronic CT features in PE patients with co-existing DVT

OBJECTIVE

Clinical features may be different in patients with PE without co-existing DVT compared to those with PE with co-existing DVT. This prospective study aims to investigate the different clinical features between patients with isolated pulmonary embolism (PE) and those with PE associated with deep venous thrombosis.

METHOD

This is a prospective study conducted in 107 consecutive patients diagnosed with acute PE in the emergency department or other departments of Kırıkkale University Hospital. The diagnosis of PE was confirmed by computed tomography pulmonary angiography (CTPA), which was ordered on the basis of symptoms and findings. Bilateral lower extremity compression ultrasound with standard 7.5 MHz linear array probe was applied to all patients. According to compression ultrasound results, the patients were divided into two classes as with and without deep venous thrombosis. Embolism in the main or lobar pulmonary arteries were classified as central, and those found only in segmental or subsegmental arteries were classified as peripheral. Laboratory parameters and Oxygen saturation were assessed on admission.

RESULTS

67 of 107 (62.6%) patients with PE were isolated pulmonary embolism, and 40 (37.4%) were PE + DVT. Patients with PE with co-existing DVT have wider pulmonary artery, higher d-dimer and pro BNP level, and lower saturation than those with isolated pulmonary embolism. Central pulmonary embolism is more common in patients with deep vein thrombus than those without it. (87.5% (35/40) vs 32.8% (22/67),p = 0.001). 38.6% of central pulmonary embolism occur without deep vein thrombosis of the lower extremities. Patients with PE with co-existing DVT have 42.5% mosaic perfusion pattern,70% chronic infarct appearance such as linear band, pleural nodüle, %15.0 thickened, small arteries and, %12.5 shrunken complete artery occlusion, suggesting the chronic background.

CONCLUSION

PE patients with co-existing DVT are clinically more serious than those who do not have a DVT. An acute picture may be present in the chronic background in a significant proportion of patients with PE with co-existing DVT. In the presence of deep vein thrombosis, pulmonary embolism is usually central, but more than one-third of central pulmonary emboli occur without lower extremity deep vein thrombosis.

Incidence of Venous Thromboembolism Following Major Emergency Abdominal Surgery

BACKGROUND

In a retrospective cohort study, we looked at the incidence and risk factors of developing in-hospital venous thromboembolism (VTE) after major emergency abdominal surgery and the risk factors for developing a venous thrombosis.

METHODS

Data were extracted through medical records from all patients undergoing major emergency abdominal surgery at a Danish University Hospital from 2010 until 2016. The primary outcome was the incidence of venous thrombosis developed in the time from surgery until discharge from hospital. The secondary outcomes were 30-day mortality and postoperative complications. Multivariate logistic analyses were used for confounder control.

RESULTS

In total, 1179 patients who underwent major emergency abdominal surgery during 2010-2016 were included. Thirteen patients developed a postoperative venous thromboembolism (1.1%) while hospitalized. Eight patients developed a pulmonary embolism all verified by CT scan and five patients developed a deep venous thrombosis verified by ultrasound scan. Patients diagnosed with a VTE were significantly longer in hospital with a length of stay of 34 versus 14 days, P < 0.001, and they suffered significantly more surgical complications (69.2% vs. 30.4%, P = 0.007). Thirty-day mortality was equal in patients with and without a venous thrombosis. In a multivariate analysis adjusting for gender, ASA group, BMI, type of surgery, dalteparin dose and treatment with anticoagulants, we found that a dalteparin dose ≥5000 IU was associated with the risk of postoperative surgical complications (odds ratio 1.55, 95% CI 1.11-2.16, P = 0.009).

CONCLUSION

In this study, we found a low incidence of venous thrombosis among patients undergoing major emergency abdominal surgery, comparable to the incidence after elective surgery.

Recurrent unilateral cellulitis: is it May-Thurner syndrome (MTS)?

May-Thurner syndrome (MTS) is a differential diagnosis to be considered in a patient with recurrent unilateral cellulitis. A 73-year-old woman initially presented with recurrent unilateral cellulitis of her left lower limb. A CT scan demonstrated a stenosed left common iliac vein (CIV) narrowed at its origin by the proximal right common iliac artery consistent with MTS. The chronicity of the condition at the time of diagnosis made attempts to recanalise the CIV unsuccessful. A diagnosis of MTS should be considered in a patient with chronic unilateral limb oedema/cellulitis as it represents a potentially treatable condition if detected early.

Prevalence of chronic venous pathology in healthcare workers and the role of upright standing

BACKGROUND

Chronic venous disease (CVD) affects around 25% of adult population in developed countries and it often represent a health problem for different kind of workers, in particular for who spend much of the working time in upright standing.

METHODS

The study was carried out on a population of 173 nonmedical workers of a midsize hospital in Italy (91 nurse, 31 support staff workers and 51 employees). The study protocol was taken from a previous study of our group and included a clinical examination and a questionnaire.

RESULTS

From the analysis of data it emerged a particular importance of upright standing as major risk factor for CVD. The prevalence of venous pathology seems to be greater among nurses and auxiliaries than the administrative staff and, as expected, it was significantly higher among female workers than in males.

CONCLUSIONS

The results obtained show that the clinical-diagnostic protocol described can be used by doctors for screening venous pathology at workplaces.

American College of Veterinary Emergency and Critical Care (ACVECC) Consensus on the Rational Use of Antithrombotics in Veterinary Critical Care (CURATIVE) guidelines: Small animal

OBJECTIVES

To systematically review available evidence and establish guidelines related to the risk of developing thrombosis and the management of small animals with antithrombotics.

DESIGN

Standardized, systematic evaluation of the literature (identified by searching Medline via PubMed and CAB abstracts) was carried out in 5 domains (Defining populations at risk; Defining rational therapeutic use; Defining evidence-based protocols; Refining and monitoring antithrombotic therapies; and Discontinuing antithrombotic therapies). Evidence evaluation was carried out using Population, Intervention, Comparison, Outcome generated within each domain questions to address specific aims. This was followed by categorization of relevant articles according to level of evidence and quality (Good, Fair, or Poor). Synthesis of these data led to the development of a series of statements. Consensus on the final guidelines was achieved via Delphi-style surveys. Draft recommendations were presented at 2 international veterinary conferences and made available for community assessment, review, and comment prior to final revisions and publication.

SETTINGS

Academic and referral veterinary medical centers.

RESULTS

Over 500 studies were reviewed in detail. Worksheets from all 5 domains generated 59 statements with 83 guideline recommendations that were refined during 3 rounds of Delphi surveys. A high degree of consensus was reached across all guideline recommendations.

CONCLUSIONS

Overall, systematic evidence evaluations yielded more than 80 recommendations for the treatment of small animals with or at risk of developing thrombosis. Numerous significant knowledge gaps were highlighted by the evidence reviews undertaken, indicating the need for substantial additional research in this field.

Upper Extremity Deep Venous Thrombosis Prophylaxis After Elective Upper Extremity Surgery

Historically, upper extremity deep venous thromboses (DVTs) have been rare; however, their incidence has increased as awareness has increased. Patients who develop upper extremity DVTs often have multiple comorbidities. However, in the past decade, studies have found a small risk of upper extremity DVTs associated with orthopedic procedures involving the upper extremity. The risk of complications following a DVT, including postthrombotic syndrome and pulmonary embolism, is substantially higher with a DVT of the upper extremity compared with a DVT of the lower extremity. Furthermore, there is no consensus regarding the role and efficacy of prophylactic measures in preventing upper extremity DVT after upper extremity surgery. This article discusses the use of prophylactic agents after elective upper extremity surgery, with an emphasis on the efficacy of commonly used interventions. [Orthopedics. 2018; 41(1):21-27.].

Impact of point-of-care ultrasound on disposition time of patients presenting with lower extremity deep vein thrombosis, done by emergency physicians

Background

Point-of-care venous compression ultrasound (VCU) is highly accurate in deep vein thrombosis (DVT) diagnosis; however, waiting to perform this exam by radiologists, may cause delay in patients' disposition.

Objective

To compare the effect of point-of-care VCU on patients' disposition time, done by emergency physician versus radiologists.

Methods

A total of 50 patients suspected of having lower extremity DVT, were randomized into 2 equal groups and they underwent a point-of-care VCU performed either by an emergency physician (emergency medicine (EM) group) or a radiologist (radiology group). The mean time of patients' disposition and management were compared between the two groups.

Results

The EM group consisted of 16 males and 9 females while the radiology group consisted of 13 males and 12 females. The median time elapsed from triage to performing ultrasonography and the median time elapsed from triage to final disposition were significantly lower in the EM group than those in the radiology group (50 min vs. 142 min, and 69 min vs. 260 min, respectively; p < .001). The final diagnosis was confirmed to be DVT in 14 patients (56%) in the EM group and in 17 patients (68%) in the radiology group (p = .38). There was no false positive or negative diagnosis.

Conclusions

Performing VCU in patients suspected of having DVT by a trained emergency physician could significantly reduce the time of patients' disposition in the emergency setting.

Increased risk of deep vein thrombosis and pulmonary thromboembolism in patients with aortic aneurysms: A nationwide cohort study

Studies on the association between aortic aneurysm (AA) and the subsequent risk of venous thromboembolism (VTE) are limited to a few case reports and investigations which only focused on surgical effects. Therefore, we used the National Health Insurance Research Database to clarify whether patients with AAs have a heightened risk of subsequent VTEs, including deep vein thrombosis (DVT) and pulmonary embolism (PE). Our retrospective cohort study comprised patients aged ≥ 18 years who received a diagnosis of an AA and were hospitalized at any point during 2000–2010 (n = 16,630). Each AA patient was frequency-matched to 4 non-AA hospitalized patients based on age, sex, and index year (n = 66,453). The Cox proportional hazard regressions model was used to estimate the adjusted effect of AAs on VTE risk. The overall incidence of DVT and PE was higher in the patients with AA than in the non-AA group patients (23.5 versus 13.2 and 13.5 versus 7.98/1,000 person-years). After adjustment for age, sex, duration of hospitalization in the study period, and comorbidities, patients with AAs were associated with a 1.88-fold higher risk of DVT and 1.90-fold higher risk of PE compared to the non-AA cohort. Patients with abdominal AAs were more likely to develop DVT, whereas thoracic AA patients were more likely to develop PE. A diagnosis of a ruptured AA was associated with a substantially increased risk of DVT. Surgical treatment of AAs was associated with a heightened risk of VTE within 6-months post-operation. Our study demonstrates that AAs are associated with an increased risk of subsequent VTE. Future investigations are encouraged to delineate the mechanisms underlying this association and to evaluate the cost-effectiveness of screening for VTEs in patients with AAs.

Histotripsy methods in mechanical disintegration of tissue: towards clinical applications

In high intensity focused ultrasound (HIFU) therapy, an ultrasound beam is focused within the body to locally affect the targeted site without damaging intervening tissues. The most common HIFU regime is thermal ablation. Recently there has been increasing interest in generating purely mechanical lesions in tissue (histotripsy). This paper provides an overview of several studies on the development of histotripsy methods toward clinical applications. Two histotripsy approaches and examples of their applications are presented. In one approach, sequences of high-amplitude, short (microsecond-long), focused ultrasound pulses periodically produce dense, energetic bubble clouds that mechanically disintegrate tissue. In an alternative approach, longer (millisecond-long) pulses with shock fronts generate boiling bubbles and the interaction of shock fronts with the resulting vapour cavity causes tissue disintegration. Recent preclinical studies on histotripsy are reviewed for treating benign prostatic hyperplasia (BPH), liver and kidney tumours, kidney stone fragmentation, enhancing anti-tumour immune response, and tissue decellularisation for regenerative medicine applications. Potential clinical advantages of the histotripsy methods are discussed. Histotripsy methods can be used to mechanically ablate a wide variety of tissues, whilst selectivity sparing structures such as large vessels. Both ultrasound and MR imaging can be used for targeting and monitoring the treatment in real time. Although the two approaches utilise different mechanisms for tissue disintegration, both have many of the same advantages and offer a promising alternative method of non-invasive surgery.

Endovascular Treatment of Deep Vein Thrombosis

Venous thromboembolism (VTE) is associated with substantial morbidity and mortality. Conventional treatment with anticoagulation therapy may undertreat the condition. Patients with VTE are at risk for recurrence with increasing time passage. Endovascular approaches exist for treating VTE, including deep vein thrombosis, but it is unclear which patients are appropriate candidates for endovascular versus medical approaches. Many new endovascular technologies are in development, and new oral anticoagulants are also on the market. Clinicians must be mindful of these new products and use them appropriately to better manage VTE.

PICC Zone Insertion Method™ (ZIM™): A Systematic Approach to Determine the Ideal Insertion Site for PICCs in the Upper Arm

The consequences of random PICC practice can be serious and manifest as deep vein thrombosis, pulmonary embolism, catheter related bloodstream infection, and post thrombotic syndrome. Risk factors related to site selection have been well established for other central venous access devices, but not for ultrasound guided PICC insertion in the upper arm. The author presents observations of upper arm PICC insertion designated by color zones to highlight the variability of PICC practice. The author also details site risk factors associated with each color zone and proposes an ideal insertion location for upper arm ultrasound guided PICC procedures.

The PICC Zone Insertion Method (ZIM) is a proposed system design for patient safety related to PICC insertions; performed by optimizing and organizing the clinical approach. It aids in identifying the Ideal Zone for upper arm needle insertion with ultrasound guidance. The significance of a systematic approach is that it is reproducible, measurable, and as a result will reduce variation in PICC insertion practice. The ZIM combines known mechanisms for vascular access insertion site complications with a systematic measuring and ultrasound scanning process, to reduce the impact of site risk factors. The impact of thrombosis cannot be underestimated, as it will likely limit the future use of veins for life saving vascular access. This issue should not be ignored by hospitals or clinicians, in fact, systematic solutions like PICC Zone Insertion Method, should be explored and supported as part of a comprehensive approach to vascular access care.

Cost-effectiveness of strategies for diagnosing pulmonary embolism among emergency department patients presenting with undifferentiated symptoms

STUDY OBJECTIVE

Symptoms associated with pulmonary embolism can be nonspecific and similar to many competing diagnoses, leading to excessive costly testing and treatment, as well as missed diagnoses. Objective studies are essential for diagnosis. This study evaluates the cost-effectiveness of different diagnostic strategies in an emergency department (ED) for patients presenting with undifferentiated symptoms suggestive of pulmonary embolism.

METHODS

Using a probabilistic decision model, we evaluated the incremental costs and effectiveness (quality-adjusted life-years gained) of 60 testing strategies for 5 patient pretest categories (distinguished by Wells score [high, moderate, or low] and whether deep venous thrombosis is clinically suspected). We performed deterministic and probabilistic sensitivity analyses.

RESULTS

In the base case, for all patient pretest categories, the most cost-effective diagnostic strategy is to use an initial enzyme-linked immunosorbent assay D-dimer test, followed by compression ultrasonography of the lower extremities if the D-dimer is above a specified cutoff. The level of the preferred cutoff varies with the Wells pretest category and whether a deep venous thrombosis is clinically suspected. D-dimer cutoffs higher than the current recommended cutoff were often preferred for patients with even moderate and high Wells categories. Compression ultrasonography accuracy had to decrease below commonly cited levels in the literature before it was not part of a preferred strategy.

CONCLUSION

When pulmonary embolism is suspected in the ED, use of an enzyme-linked immunosorbent assay D-dimer assay, often at cutoffs higher than those currently in use (for patients in whom deep venous thrombosis is not clinically suspected), followed by compression ultrasonography as appropriate, can reduce costs and improve outcomes.

[Importance of D-dimer testing in ambulatory detection of atypical and "silent" phlebothrombosis]

BACKGROUND/AIM

Deep venous thrombosis (DVT) is a life-threatening condition, which could be manifested with discrete symptoms (silent DVT). High mortality and disability of patients with DVT indicate the importance of early diagnosis, especially of "silent" DVT. The aim of this paper was to evaluate of reliability of early detection model for diagnosing DVT in ambulatory patients by using clinical probability of DVT presence, D-dimmer test (DD) and ultrasound evaluation (US).

METHODS

Ambulatory patients with suspected DVT were classified as "unlikely" and "likely" DVT by the Wells clinical model. The patients were randomly divided into the control and DD group. In the control group (629 patients) only US examination of lower limbs deep vein was done. All patients in the DD group (643 patients), with "unlikely" TDV, had DD, and in the positive patients US examination was done. In the "likely" patients US examination was done and negative US finding indicated DD test. Positive DD test was an indication for US examination after 7 days. The patients with initially excluded DVT were evaluated during 3 months.

RESULTS

A total number of 1 272 patients were examined; 117 (9.19%) patients were with DVT--62 (9.640%) in the DD and 55 (8.74%) in the control group. During the follow-up periods in the DD group (with 582 initially excluded DVT) we registered DVT in only one patient (0.17%). It was significantly lower (p < 0.05) compared to the control group where we registered 7 (1.10%) DVT (a group with 581 initially excluded DVT). The applied DD diagnostic strategy for 70.7% (p < 0.001) reduced the need for US examination.

CONCLUSION

The applied DD strategy in the diagnostic of DVT reduces the need for US examinations and reduces frequency of false negative results, with direct impact on cost and efficacy of procedures. DD diagnostic model should replace serial US examination in patients with suspect DVT.

Endovascular treatment for iliac vein compression syndrome: a comparison between the presence and absence of secondary thrombosis

Objective

To evaluate the value of early identification and endovascular treatment of iliac vein compression syndrome (IVCS), with or without deep vein thrombosis (DVT).

Materials and Methods

Three groups of patients, IVCS without DVT (group 1, n = 39), IVCS with fresh thrombosis (group 2, n = 52) and IVCS with non-fresh thrombosis (group 3, n = 34) were detected by Doppler ultrasonography, magnetic resonance venography, computed tomography or venography. The fresh venous thrombosis were treated by aspiration and thrombectomy, whereas the iliac vein compression per se were treated with a self-expandable stent. In cases with fresh thrombus, the inferior vena cava filter was inserted before the thrombosis suction, mechanical thrombus ablation, percutaneous transluminal angioplasty, stenting or transcatheter thrombolysis.

Results

Stenting was performed in 111 patients (38 of 39 group 1 patients and 73 of 86 group 2 or 3 patients). The stenting was tried in one of group 1 and in three of group 2 or 3 patients only to fail. The initial patency rates were 95% (group 1), 89% (group 2) and 65% (group 3), respectively and were significantly different (p = 0.001). Further, the six month patency rates were 93% (group 1), 83% (group 2) and 50% (group 3), respectively, and were similarly significantly different (p = 0.001). Both the initial and six month patency rates in the IVCS patients (without thrombosis or with fresh thrombosis), were significantly greater than the patency rates of IVCS patients with non-fresh thrombosis.

Conclusion

From the cases examined, the study suggests that endovascular treatment of IVCS, with or without thrombosis, is effective.

Postoperative venous thromboembolism rates vary significantly after different types of major abdominal operations

BACKGROUND

Venous thrombolism (VTE) is a significant cause of morbidity for surgical patients. Comparative risk across major procedures is unknown.

METHODS

Retrospective analysis of the Nationwide Inpatient Sample (2001-2005) was conducted. Eight surgeries were identified: bariatric surgery, colorectal surgery, esophagectomy, gastrectomy, hepatectomy, nephrectomy, pancreatectomy, splenectomy. Age < 18, patients with multiple major surgeries, and those admitted for treatment of VTE were excluded. Primary outcome was occurrence of VTE. Independent variables included age, gender, race, Charlson score, hospital teaching status, elective procedures, cancer/metastasis, trauma, and year.

RESULTS

Patients, 375,748, were identified, 5,773 (1.54%) with VTE. Overall death rate was 3.97%, but 13.34% after VTE. Unadjusted rate (0.35%) and adjusted risk for VTE were lowest among bariatric patients. On multivariate analysis, highest risk for VTE was splenectomy (odds ratio 2.69, 95% CI 2.03-3.56). Odds ratio of in-hospital mortality following VTE was 1.84 (1.65-2.05), associated with excess stay of 10.88days and $9,612 excess charges, translating into $55 million/year nationwide.

CONCLUSION

Highest risk for VTE was associated with splenectomy, lowest risk with bariatric surgery. Since bariatric patients are known to have greater risk for this complication, these findings may reflect better awareness/prophylaxis. Further studies are necessary to quantify effect of best-practice guidelines on prevention of this costly complication.

Mechanical compression in the prophylaxis of venous thromboembolism

Venous thromboembolism (VTE) is an important cause of morbidity and mortality in a substantial number of the Australian community. There exists a considerable range of potential prophylactic measures aimed at reducing the risk of VTE. These antithrombotic regimens include pharmacological interventions and mechanical techniques to counteract venous stasis including graduated compression stockings and intermittent pneumatic compression (IPC) devices. This review particularly concentrates on evidence for the use of mechanical prophylaxis and the interrelationship with pharmacological methods of VTE prophylaxis. Mechanical and pharmacological methods of VTE prophylaxis are both effective and when used in combination have synergistic effects. Although there are a number of different IPC systems, little evidence is available at present that differentiates these on the basis of VTE prevention. Compliance and patient acceptance of IPC as a preventative measure has improved with miniaturization and device weight reduction. IPC should be used according to recommended guidelines. In moderate-risk patients when pharmacological prophylaxis is contraindicated, IPC can be used as an alternative. High-risk patients should receive both mechanical and pharmacological prophylaxis to reduce their relative risk. Until further evidence becomes available, the specific type of IPC unit chosen will generally be determined by ease of use, availability and cost.

A patient with deep vein thrombosis presenting to a chiropractic clinic: a case report

OBJECTIVE

The objective of this article is to present and discuss a case of deep vein thrombosis in a chiropractic clinic setting.

CLINICAL FEATURES

A 33-year-old male patient presented for follow-up chiropractic care for a long-term low back complaint. A working diagnosis of facet joint syndrome was made. Despite improvement of low back symptoms, the patient experienced right-sided groin pain. The patient was referred to the hospital with a provisional diagnosis of deep vein thrombosis.

INTERVENTIONS AND OUTCOMES

The patient consulted a physician, and within 2 hours of chiropractic consultation, his entire leg had become painful. Doppler ultrasound revealed extensive thrombosis. He was placed on heparin and was hospitalized for 8 days. On discharge, a full-length right leg stocking and moderate exercise were recommended. Consecutive checkups were scheduled with the clot almost resolved at 19 months postdiagnosis.

CONCLUSION

This case report highlights the importance for the manipulative therapist to be aware of cardiovascular disease mechanisms and associated risk factors, so comanagement via referral to the appropriate specialist can occur.

Deep vein thrombosis in an athletic military cadet

STUDY DESIGN

Resident's case problem.

BACKGROUND

A 21-year-old healthy athletic male military cadet with complaint of worsening diffuse left knee pain was evaluated 4 days after onset. The knee pain began 2 hours after completing a long car trip, worsened over the subsequent 3 days, and became almost unbearable during the return trip. The patient reported constant pain, limited knee motion, and difficulty ambulating. In addition, he was unable to perform physical military training or attend academic classes due to the severe left knee pain. Past medical history revealed a mild left lateral calf strain 21/2 weeks prior, which completely resolved within 24 hours of onset.

DIAGNOSIS

Our physical examination led us to either monoarticular arthritis, pseudothrombophlebitis (ruptured Baker's cyst), or a lower leg deep vein thrombosis (DVT) as the cause of knee pain. Diagnostic imaging of this patient revealed a left superficial femoral vein thrombosis and popliteal DVT, with bilateral pulmonary emboli (PE).

DISCUSSION

A systematic differential diagnosis was undertaken to rule out a potentially fatal DVT diagnosis as the cause of knee pain, despite minimal DVT risk factors. The physical therapist in a direct-access setting must ensure timely evaluation and referral of a suspected DVT, even when patient demographics cause the practitioner to question the likelihood of this diagnosis. The physical examination findings, clinical suspicion, and established clinical prediction rules can accurately dictate the appropriate referral action necessary.