Allastair B. Karmody Award. Calf vein thrombi are not a benign finding

Significance and management of isolated distal deep vein thrombosis

PURPOSE OF REVIEW

Management of isolated distal deep vein thrombosis (IDDVT) remains controversial. We summarize recent studies regarding the natural history of IDDVT as well as pertinent therapeutic trials. We also provide our management approach.

RECENT FINDINGS

IDDVT is more commonly associated with transient risk factors and less often associated with permanent, unmodifiable risk factors than proximal DVT. IDDVT has a significantly lower risk of proximal extension and recurrence than proximal DVT. Cancer-associated IDDVT has a similar natural history to cancer-associated proximal DVT, with substantially less favourable outcomes than noncancer-associated IDDVT. Anticoagulant treatment reduces the risk of proximal extension and recurrence in IDDVT at the cost of increased bleeding risk. Intermediate dosing of anticoagulation may be effective for treating noncancer-associated IDDVT in patients without prior DVT.

SUMMARY

IDDVT with a transient risk factor can be treated for 6 weeks in patients without a prior DVT. Unprovoked IDDVT in patients without malignancy can be treated for 3 months. Outpatients without malignancy or a prior DVT can be left untreated and undergo surveillance compression ultrasound in one week to detect proximal extension, but few patients opt for this in practice. Cancer-associated IDDVT should be treated analogously to cancer-associated proximal DVT.

Incidence and risk factors for deep venous thrombosis of lower extremity after surgical treatment of isolated patella fractures

Background

Limited information exists on the incidence of postoperative deep venous thromboembolism (DVT) in patients with isolated patella fractures. The objective of this study was to investigate the postoperative incidence and locations of deep venous thrombosis (DVT) of the lower extremity in patients who underwent isolated patella fractures and identify the associated risk factors.

Methods

Medical data of 716 hospitalized patients was collected. The patients had acute isolated patella fractures and were admitted at the 3rd Hospital of Hebei Medical University between January 1, 2016, and February 31, 2019. All patients met the inclusion criteria. Medical data was collected using the inpatient record system, which included the patient demographics, patient’s bad hobbies, comorbidities, past medical history, fracture and surgery-related factors, hematological biomarkers, total hospital stay, and preoperative stay. Doppler examination was conducted for the diagnosis of DVT. Univariate analyses and multivariate logistic regression analyses were used to identify the independent risk factors.

Results

Among the 716 patients, DVT was confirmed in 29 cases, indicating an incidence of 4.1%. DVT involved bilateral limbs (injured and uninjured) in one patient (3.4%). DVT involved superficial femoral common vein in 1 case (3.4%), popliteal vein in 6 cases (20.7%), posterior tibial vein in 11 cases (37.9%), and peroneal vein in 11 cases (37.9%). The median of the interval between surgery and diagnosis of DVT was 4.0 days (range, 1.0-8.0 days). Six variables were identified to be independent risk factors for DVT which included age category (> 65 years old), OR, 4.44 (1.34-14.71); arrhythmia, OR, 4.41 (1.20-16.15); intra-operative blood loss, OR, 1.01 (1.00-1.02); preoperative stay (delay of each day), OR, 1.43 (1.15-1.78); surgical duration, OR, 1.04 (1.03-1.06); LDL-C (> 3.37 mmol/L), OR, 2.98 (1.14-7.76).

Conclusion

Incidence of postoperative DVT in patients with isolated patella fractures is substantial. More attentions should be paid on postoperative DVT prophylaxis in patients with isolated patella fractures. Identification of associated risk factors can help clinicians recognize the risk population, assess the risk of DVT, and develop personalized prophylaxis strategies.

High Signal Intensity on Diffusion-Weighted Images Reflects Acute Phase of Deep Vein Thrombus

The effects of antithrombotic therapy on deep vein thrombosis (DVT) can be affected by thrombus age, which cannot be reliably determined by noninvasive imaging modalities. We investigated whether magnetic resonance (MR) diffusion-weighted imaging (DWI) can localize and determine the age of venous thrombus in patients with DVT, animal models, and human blood in vitro. Signal intensity (SI) on DWI and the apparent diffusion coefficient (ADC) of thrombi were assessed in eight patients with DVT using a 1.5-T MR imaging (MRI) system. We assessed the organizing processes as venous thrombus developed in the rabbit jugular vein using a 3.0-T MRI system over time. We also assessed MRI signals of human blood in vitro using the 1.5-T MRI system. Venous thrombi were detected by DWI as areas of high or mixed high and iso SI in all patients. The ADCs were lower in the proximal, than in the distal portion of the thrombi. The thrombi of rabbit jugular veins histologically organized in a time-dependent manner, with high SI on DWI at 4 hours, mixed high and iso SI at 1 and 2 weeks, and iso SI at 3 weeks. The ADC correlated negatively with erythrocyte content, and positively with smooth muscle cells, macrophages, hemosiderin, and collagen content. MRI signals of human blood in vitro showed that ADCs were affected by erythrocyte content, but not by blood clotting. MR-DWI can detect venous thrombus, and high SI on DWI accompanied by a low ADC might reflect erythrocyte-rich, acute-phase thrombi.

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.

Prevalence of Deep Vein Thrombosis in Low-Risk Patients After Elective Foot and Ankle Surgery

BACKGROUND:

The evidence regarding the prevalence of deep vein thrombosis (DVT) after foot and ankle surgery in elective patients that need to be 6 weeks non-weight bearing postoperatively is incomplete and has limitations.

METHODS:

The prevalence of DVT in 114 procedures involving the hindfoot and midfoot was determined using ultrasonographic surveillance at 2 and 6 weeks after surgery.

RESULTS:

The prevalence of DVT was observed to be 25.4%. The majority (68.9%) of DVTs were diagnosed at the ultrasonographic scan performed 2 weeks postoperatively. The remainder (31.1%) of DVTs were diagnosed at the 6-week postoperative ultrasonographic scan. At least 75% of the patients who had early and late DVT had no clinical symptoms or signs of DVT. The prevalence of DVT in clinically detectable patients was 6%. The average age of patients with early DVT was 62.2 years, significantly higher compared to those who had no DVT. The mean tourniquet time for patients with early DVT was 68.1 minutes, significantly higher compared to those without DVT. All DVTs detected were distal to the popliteal vein.

CONCLUSIONS:

The prevalence of clinically silent DVT was significantly higher than was previously thought. We believe this increased rate is directly attributable to the use of ultrasonographic surveillance postsurgery both at 2 and 6 weeks. The risk of DVT continued after the 2-week visit, and 30% of the DVTs were detected at the ultrasonographic scan at 6 weeks.

LEVEL OF EVIDENCE:

Level II, prospective cohort.

Repair of Chronic Achilles Ruptures Has a High Incidence of Venous Thromboembolism

BACKGROUND

Despite the low incidence of deep vein thrombosis (DVT) in foot and ankle surgery, some authors report a high incidence of symptomatic DVT following Achilles tendon rupture. The purpose of this study was to identify DVT risk factors inherent to Achilles tendon repair to determine which patients may benefit from prophylaxis.

METHODS

One hundred and thirteen patient charts were reviewed following elective and nonelective Achilles tendon repair. For elective repair of insertional or noninsertional Achilles tendinopathy, parameters examined included lateral versus prone positioning and the presence versus absence of a flexor hallucis longus transfer. For nonelective repair, acute Achilles tendon ruptures were compared to chronic Achilles tendon ruptures.

RESULTS

Of 113 Achilles tendon repairs, 3 venous thromboembolism (VTE) events (2.65%) occurred including 2 pulmonary emboli (1.77%). Seventeen of these repairs were chronic Achilles tendon ruptures, and all 3 VTE events (17.6%) occurred within this subgroup. Elevated body mass index was associated with VTE in patients with chronic Achilles ruptures although this did not reach significance ( P = .064). No VTE events were reported after repair of 28 acute tendon ruptures or after 68 elective repairs of tendinopathy. Two patients with misdiagnosed partial Achilles tendon tears were excluded because they experienced a VTE event 3 weeks and 5 weeks after injury, prior to surgery.

CONCLUSION

In our retrospective review, chronic Achilles ruptures had a statistically significant higher incidence of VTE compared with acute Achilles ruptures ( P = .048) or elective repair ( P = .0069). Pharmaceutical anticoagulation may be considered for repair of chronic ruptures. Repair of acute ruptures and elective repair may not warrant routine prophylaxis due to a lower incidence of VTE.

LEVELS OF EVIDENCE

Prognostic, Level III: Case Control Study.

Lower-extremity venous ultrasound - past, present and future

Deep vein thrombosis is a frequent clinical concern and imaging request in the pediatric population. There has been increased awareness of deep venous thrombosis in the pediatric population and sonography is now utilized more liberally and frequently to evaluate for thrombosis in the extremities. In this review the author discusses various aspects of deep vein thrombosis in the lower extremity including the pathophysiology, background, and morbidity in children. The current ultrasound guidelines and techniques, and the controversy over treatment are discussed as well.

Anticoagulation in patients with isolated distal deep vein thrombosis: a meta-analysis

Essentials The optimal management of isolated distal deep vein thrombosis (IDDVT) is undefined. This meta-analysis aimed to assess the clinical benefit of anticoagulation for IDDVT. Anticoagulation reduced the rate of pulmonary embolism without increasing major bleeding risk. Recurrent thromboembolism was less common with more than 6 weeks vs. 6 weeks of anticoagulation.

SUMMARY

Background The optimal management of patients with isolated distal deep vein thrombosis (IDDVT), concerning both the need for anticoagulation and its duration, is undefined. Objectives We performed a meta-analysis of randomized and cohort studies in patients with IDDVT to assess the clinical benefit of: (i) anticoagulation versus no anticoagulation; and (ii) anticoagulant treatment for 6 weeks versus for > 6 weeks. Methods The primary outcome of this analysis was recurrent venous thromboembolism (proximal propagation, recurrence of deep vein thrombosis, and pulmonary embolism). Data were pooled and compared by the use of odds ratio (OR) and 95% confidence interval (CI). Results A reduction in the rate of recurrent venous thromboembolism was observed in patients who received anticoagulation relative to those who did not receive anticoagulation (either therapeutic or prophylactic) (20 studies, 2936 patients; OR 0.50, 95% CI 0.31-0.79), without an increase in the risk of major bleeding (OR 0.64, 95% CI 0.15-2.73). The rate of pulmonary embolism was lower in anticoagulant-treated patients than in controls (15 studies, 1997 patients; OR 0.48, 95% CI 0.25-0.91). A lower rate of recurrent venous thromboembolism was observed in patients who received > 6 weeks of anticoagulant therapy than in those who received 6 weeks of anticoagulant therapy (four studies, 1136 patients; OR 0.39, 95% CI 0.17-0.90). Conclusions In patients with IDDVT, anticoagulation (both therapeutic and prophylactic) reduces the rate of recurrent venous thromboembolism and the incidence of pulmonary embolism as compared with no anticoagulation, without an increased risk of major bleeding. Anticoagulation for > 6 weeks should be preferred over shorter durations.

Predictable factors of deep venous thrombosis in patients undergoing spine surgery

BACKGROUND

DVT is one of the major postoperative complications of joint replacement surgery of the lower extremity which can cause catastrophic complications such as pulmonary embolism. However, little is known about the incidence of DVT after spine surgery. The purpose of this study was to examine predictable factors of DVT after spine surgery.

METHODS

This study included 194 patients who underwent spine surgery (104 males, 90 females, mean age 65.7 years). Postoperative DVT was detected using duplex ultrasonography (DUS). Age, sex, BMI, operation time, amount of bleeding, preoperative ambulatory status, usage of instrumentation, and preoperative serum levels of D-dimer were compared between the DVT(+) and DVT(-) groups to establish predictors for postoperative DVT. Cut-off value of the preoperative level of D-dimer was calculated using ROC analysis.

RESULTS

Postoperative DVT was detected in 57 patients (29.4%). No patients showed clinical signs of DVT or pulmonary embolism. Sex, age, BMI, preoperative non-ambulatory status, and preoperative levels of D-dimer were significantly different between the DVT(+) and DVT(-) groups. However, age and BMI was not significantly different factor in logistic regression analysis. Cut-off value of preoperative D-dimer was 1.4 μg/ml.

CONCLUSION

It was suggested that perioperative application of DUS for detecting DVT in the lower extremities should be performed on patients undergoing spine surgery who are female, non-ambulatory, and with higher preoperative D-dimer serum level.

Deep Venous Thrombosis and Tendon Healing

Tendon metabolism after acute Achilles tendon rupture (ATR) is associated with major complications related to immobilization, which results in reduced circulation, high risk of deep venous thrombosis (DVT), impaired healing and functional deficits.DVT has been demonstrated to occur in up to 50 % of the patients with ATR. Suffering from a DVT during tendon healing has been demonstrated as an independent predictive factor for impaired patient outcome at 1 year after ATR, suggesting that specific interventions are warranted to prevent DVT. Since pharmacological DVT prophylaxis has low or no effect during lower leg immobilization it is speculated whether adjuvant treatment with intermittent pneumatic compression (IPC) applied during lower limb immobilization can reduce the incidence of DVT.IPC, which acts through mechanical, chemical and molecular mechanisms, has been demonstrated to enhance neuro-vascular ingrowth in a tendon repair model and stimulate collagen production leading to improved maximum force during healing.Recently, a prospective randomized trial compared adjuvant IPC applied under an orthosis versus plaster cast only in ATR patients. The study found at 2 weeks post-operatively 21 % DVTs in the IPC-group compared to 37 % in the control group. Patients that received no IPC treatment exhibited an almost threefold increased odds for DVT, independently of age. Furthermore, using microdialysis technique, adjuvant IPC treatment was shown to increase the metabolic healing activity at 2 weeks post-ATR.Tendon healing is impaired by reduced circulation and DVT. The demonstration that adjuvant IPC effectively reduced DVT incidence, and also is capable of enhancing the metabolic response suggests that IPC treatment may not only be a viable means of prophylaxis against DVT, but possibly also a method of promoting healing.

Clinical Significance of the Soleal Vein and Related Drainage Veins, in Calf Vein Thrombosis in Autopsy Cases with Massive Pulmonary Thromboembolism

OBJECTIVE

To clarify the histopathological characteristics of deep vein thrombosis (DVT) resulting in lethal pulmonary thromboembolism (PE).

SUBJECTS AND METHODS

We investigated 100 autopsy cases of PE from limb DVT. The distribution and chronology of DVT in each deep venous segment were examined. Venous segments were classified into three groups: iliofemoral vein, popliteal vein and calf vein (CV). The CV was subdivided into two subgroups, drainage veins of the soleal vein (SV) and non drainage veins of SV.

RESULTS

Eighty-nine patients had bilateral limb DVTs. CV was involved in all limbs with DVT with isolated calf DVTs were seen in 47% of patients. Fresh and organized thrombi were detected in 84% of patients. SV showed the highest incidence of DVTs in eight venous segments. The incidence of DVT gradually decreased according to the drainage route of the central SV. Proximal tips of fresh thrombi were mainly located in the popliteal vein and tibioperoneal trunk, occurring in these locations in 63% of limbs.

CONCLUSIONS

SV is considered to be the primary site of DVT; the DVT then propagated to proximal veins through the drainage veins. Lethal thromboemboli would occur at proximal veins as a result of proximal propagation from calf DVTs.

Current management of isolated soleal and gastrocnemius vein thrombosis

Thrombi of the soleal and gastrocnemius veins of the leg remain incompletely characterized in terms of the appropriate treatment algorithm to follow. Although they are anatomically located below the level of the fascia, making them "deep" vein thrombi, their natural history is unclear with respect to propagation and embolization. Varying treatment suggestions have been proposed, from full-dose anticoagulation to "watchful waiting" with repeated duplex examination, with none rising to the level of accepted scientific evidence. Herein, we present the current literature citing the differing opinions and data that have confused the subject.

No consensus exists for use of anticoagulation for calf vein thrombosis

The ideal treatment of calf vein thrombosis (CVT) remains undefined. We assessed practice patterns at a single institution for CVT. Physicians were sent an online survey with 8 multiple choice questions about management of CVT. A total of 99 physicians of varying specialties participated in the survey. A total of 48.5% anticoagulate patients with CVT and 51.5% do not. Of those who anticoagulate, 62.3% use low molecular weight heparin and 11% use IV heparin. Treatment duration is 3 months for 58% and 6 months for 30% of responders. Of those who do not anticoagulate, 71.2% reassess for clot propagation or resolution with a duplex exam. IVC filters are used by 46% when there is a contraindication to anticoagulation and 13.7% when clot propagation is noted on follow-up scan. These results suggest that there is no consensus treatment of CVT. There is a higher than expected rate of IVC filters placed for CVT.

Incidence of symptomatic deep venous thrombosis after Achilles tendon rupture

Deep venous thrombosis (DVT) is a significant source of morbidity and mortality and is associated with many orthopedic procedures. Previous studies have reported highly variable DVT rates in patients with Achilles tendon rupture undergoing operative and nonoperative treatment. We performed a retrospective chart review for all patients who underwent Achilles tendon repair at our institution from January 2006 to February 2012. Patient data were collected from the electronic medical record system. A total of 115 patients were eligible for the present study. Of these patients, 27 (23.47%) with a surgically treated Achilles tendon rupture developed a symptomatic DVT either while waiting for, or after, surgical intervention, with approximately one third of these diagnosed before surgical intervention. Of the 27 patients with DVT, 3 had a proximal DVT and 24 had a distal DVT. One patient developed a pulmonary embolism. The DVT incidence was greater in the 2 older age groups (40 to 59 and 60 to 79 years) compared individually with the younger age group (20 to 39 years; p < .0026 and p < .0014, respectively). We have shown a high incidence of DVT after Achilles tendon rupture. We recommend a high level of suspicion for the signs and symptoms of DVT during the follow-up period. In addition, patient education and early mobilization should be advocated, especially for patients older than 40 years. Additional randomized controlled trials investigating any benefits to pharmaceutical DVT prophylaxis in this population are needed to establish evidence-based recommendations.

The effects of location and low-molecular-weight heparin administration on deep vein thrombosis outcomes in trauma patients

BACKGROUND

Deep vein thrombosis (DVT) is common after trauma. Pulmonary embolism (PE) is a feared complication of DVT. Standard doses of low-molecular-weight heparin (LMWH) are commonly used to prevent and treat DVT and PE. There is variable bioavailability of LMWH with standard therapy. The traditional concept that below-knee DVT is associated with a lower risk of subsequent PE may result in less aggressive therapy. The purposes of this study were to assess the rates of PE in above-knee versus below-knee DVT and longitudinally evaluate outcomes of DVT treated with LMWH therapy.

METHODS

This was a retrospective review of patients at a university Level I trauma center during the years 2005 through 2010. Patients diagnosed with lower-extremity DVT were included in this study. Patients were classified by location of lower-extremity DVT and type of LMWH therapy received. All high-risk trauma patients were evaluated with weekly duplex Doppler ultrasonography. All duplex studies were reviewed for DVT resolution or improvement. Symptomatic patients were evaluated with computed tomographic angiography to rule out PE. Demographics, total length of hospital stay, length of intensive care unit stay, and Injury Severity Score (ISS) were collected.

RESULTS

Three-hundred eight trauma patients with lower-extremity DVT were included. More patients developed below-knee DVT (65.6%) compared with above-knee DVT (34.4%). Increased length of hospital stay, intensive care unit stay, and higher ISS were noted in patients with above-knee DVT. More patients had below-knee DVT in the prophylactic dosing group. With LMWH therapy, three PEs occurred in patients in the prophylactic dosing group with below-knee DVT, and no PEs occurred in the therapeutic treatment group. The incidence of PE between patients with below-knee DVT compared with above-knee DVT overall was not different (3.3% and 4.7%, p = 0.59). To assess DVT outcomes, 157 of the 308 patients had serial duplex studies following diagnosis of lower-extremity DVT. The number of patients receiving either therapeutic or prophylactic LMWH was similar (51% and 49%). There was no difference in rates of resolution or improvement between LMWH dosing groups or location of DVT.

CONCLUSION

In screened trauma patients, below-knee DVT is more common than above-knee DVT. There was no difference in the incidence of PE between groups. Standard prophylactic and therapeutic dosing of LMWH does not affect the rates of resolution or improvement of lower-extremity DVT. Rates of resolution and improvement of DVT is not dependent of location of lower-extremity DVT.

LEVEL OF EVIDENCE

Therapeutic study, level IV; epidemiologic study, level III.

[Usefulness of low kilovoltage settings in computed tomography venography of lower limbs]

It has been reported that a reduction in tube kilovoltage during computed tomography (CT) angiography results in an average reduction of the effective radiation dose. Furthermore, a lower kilovoltage has been shown as a technique dose. However, there is no fundamental data in a low-kilovoltage protocol for CT venography. Thus, the purpose of this study was to investigate contrast enhancement, image noise, and radiation exposure with lower kilovoltage on CT images scanned using phantom of lower limbs and clinical CT images. In order to grasp the effective energy in each tube voltage of the equipment used, we determined the half-value layer using aluminum attenuation coefficient. The phantom of the lower was sealed with contrast agent that was adjusted in various CT values. We scanned this phantom at 80 kVp, 100 kVp, and 120 kVp settings, and evaluated the changes in CT value. We also compared CT values, CTDIvol, contrast enhancement, and radiation exposure with 100 kVp and 120 kVp in patients with suspected pulmonary embolism or deep venous thrombosis. We found the CT value increased 30 HU with 100 kVp settings, and contrast was also improved. A reduction of radiation exposure without deterioration of image quality would be possible by lowering the kilovoltage setting in CT venography.

[Epidemiology and management of isolated distal deep venous thrombosis]

Isolated distal deep-vein thromboses (DVT) are infra-popliteal DVT without involvement of proximal veins or pulmonary embolism (PE). They can affect deep calf (tibial anterior, tibial posterior, or peroneal) or muscular (gastrocnemius or soleal) veins. They represent half of all lower limbs DVT. Proximal and distal DVTs differ in terms of risk factor profile, proximal DVT being more frequently associated with chronic risk factors and distal DVT with transient ones. Their natural history (rate of spontaneous proximal extension) is debated leading to uncertainties on the need to diagnose and treat them with anticoagulant drugs. In the long term, the risk of venous thromboembolic recurrence is lower than that of proximal DVT and their absolute risk of post-thrombotic syndrome is unknown. French national guidelines suggest treating with anticoagulants for 6 weeks a first episode of isolated distal DVT provoked by a transient risk factor and treating for at least 3 months unprovoked or recurrent or active cancer-related distal DVT. The use of compression stockings use is suggested in case of deep calf vein thrombosis. Ongoing therapeutic trials should provide important data necessary to establish an evidence-based mode of care, especially about the need to treat distal DVT at low risk of extension with anticoagulants.

Early treatment outcome of isolated calf vein thrombosis after total knee arthroplasty

Purpose

In contrast to proximal deep vein thrombosis (DVT), the treatment of isolated calf vein thrombosis (ICVT) remains controversial. This study aimed to investigate early treatment outcomes of ICVT after total knee arthroplasty (TKA).

Methods

Medical records of 313 patients who underwent TKA from October 2007 to December 2009 were retrospectively reviewed. A DVT-computed tomography (CT) was performed 7 days after surgery. ICVT was identified in 76 limbs of 73 patients. Of them, follow-up DVT-CT was available in 39 limbs of 37 patients. The patients with ICVTs were categorized into two groups: oral anticoagulation group (group I, 17 patients with 18 limbs) and conservative treatment group (group II, 20 patients with 21 limbs). Group I received an oral vitamin K antagonist for 3 to 6 months following low molecular weight heparin. Change of thrombus extent and development of pulmonary embolism (PE) was assessed in follow-up DVT-CT.

Results

Mean age was 68 years and 95% were female. Of 39 limbs with ICVT, 16 (41%) involved major lower leg veins (posterior tibial vein or peroneal vein), 13 (33%) involved muscular veins (soleal vein or gastrocnemius vein) and 10 (26%) involved both. During 1 to 6 months, follow-up DVT-CT revealed complete thrombus resolution in all limbs and there was no proximal propagation of thrombus or PE in both groups.

Conclusion

There is no evidence of DVT propagation or newly developed PE in the conservative treatment group. This result suggests that anticoagulation therapy for ICVT patients without PE after TKA may not be mandatory.

The Anticoagulation of Calf Thrombosis (ACT) project: study protocol for a randomized controlled trial

BACKGROUND

Half of all lower limb deep vein thrombi (DVT) in symptomatic ambulatory patients are located in the distal (calf) veins. While proximal disease warrants therapeutic anticoagulation to reduce the associated risks, distal DVT often goes untreated. However, a proportion of untreated distal disease will undoubtedly propagate or embolize. Concern also exists that untreated disease could lead to long-term post thrombotic changes. Currently, it is not possible to predict which distal thrombi will develop such complications. Whether these potential risks outweigh those associated with unrestricted anticoagulation remains unclear. The Anticoagulation of Calf Thrombosis (ACT) trial aims to compare therapeutic anticoagulation against conservative management for patients with acute symptomatic distal deep vein thrombosis.

METHODS

ACT is a pragmatic, open-label, randomized controlled trial. Adult patients diagnosed with acute distal DVT will be allocated to either therapeutic anticoagulation or conservative management. All patients will undergo 3 months of clinical and assessor blinded sonographic follow-up, followed by 2-year final review. The project will commence initially as an external pilot study, recruiting over a 16-month period at a single center to assess feasibility measures and clinical event rates. Primary outcome measures will assess feasibility endpoints. Secondary clinical outcomes will be collected to gather accurate data for the design of a definitive clinical trial and will include: (1) a composite endpoint combining thrombus propagation to the popliteal vein or above, development of symptomatic pulmonary embolism or sudden death attributable to venous thromboembolic disease; (2) the incidence of major and minor bleeding episodes; (3) the incidence of post-thrombotic leg syndrome at 2 years using a validated screening tool; and (4) the incidence of venous thromboembolism (VTE) recurrence at 2 years.

DISCUSSION

The ACT trial will explore the feasibility of comparing therapeutic anticoagulation to conservative management in acute distal DVT, within a modern cohort. We also aim to provide contemporary data on clot propagation, bleeding rates and long-term outcomes within both groups. These results will inform the conduct of a definitive study if feasibility is established.

The incidence of thromboembolic events in surgically treated ankle fracture

BACKGROUND

Thromboembolic events occur following musculoskeletal injury, and some have serious sequelae, including death. The purpose of this study was to determine the incidence of thromboembolic events and its relationship with risk factors in ambulatory patients with ankle fracture requiring open reduction and internal fixation.

METHODS

We conducted a retrospective chart review of 2478 patients who underwent open reduction and internal fixation of an ankle fracture at any one of three university hospitals between January 1, 1997, and April 30, 2005. One thousand five hundred and forty patients meeting the inclusion criteria and with complete records (minimum follow-up, six months) were identified. The median age of the patients at the time of surgery was forty-six years, and there was an equal proportion of male and female patients. Fracture types included 45% unimalleolar fractures, 31% bimalleolar, and 24% trimalleolar. Charts were reviewed to identify thromboembolic events, risk factors (neoplasia, hormone use, pregnancy, blood dyscrasia, history of a previous thromboembolic event, a current history of smoking, obesity, dyslipidemia, atherosclerotic vascular disease, or paralysis), and use of thromboprophylactic agents. A thromboembolic event was defined as symptomatic when deep venous thrombosis was confirmed with use of Doppler ultrasonography or when pulmonary embolism was confirmed with use of ventilation and perfusion scintigraphy or helical computed tomography.

RESULTS

The incidence of thromboembolic events was 2.99% (forty-six patients), with 2.66% (forty-one patients) involving a deep venous thrombosis and 0.32% (five patients) involving a nonfatal pulmonary embolism. There were no fatal pulmonary emboli recorded. The incidence did not differ among hospitals. Of the 1540 patients, 16.43% received thromboprophylaxis during their hospital stay and for six weeks (for the 10.78% taking low-molecular-weight heparin) or three months (for the 5.65% taking warfarin) after discharge without significantly modifying the incidence of thromboembolic events (2.56% vs. 2.37%, relative risk = 0.91). However patients with one or more risk factors had a greater risk of a thromboembolic event than did patients with no risk factors (3.59% vs. 2.38%, respectively; relative risk = 0.66). The use of thromboprophylaxis had no apparent impact on the occurrence of thromboembolic events in patients who did or did not have risk factors (3.68% vs. 3.55%, respectively; relative risk = 0.96). No significant correlation could be identified between the occurrence of thromboembolic events and fracture types, age, or sex.

CONCLUSIONS

Clinically detectable thromboembolic events after surgical treatment of ankle fractures are uncommon and do not appear to be influenced by the use of thromboprophylaxis. Patients with risk factors appear to be at higher risk for these events, but there is a need for prospective studies to determine the efficacy of thromboprophylaxis after surgical treatment of ankle fractures.

Relation between Isolated Venous Thrombi in Soleal Muscle and Positive Anti-Nuclear Antibody

OBJECTIVE

In patients with isolated soleal vein thrombosis (SVT), the relation between acute thrombi and positive anti-nuclear antibody (ANA) was investigated.

SUBJECTS AND METHODS

The subjects were 116 lower extremities in 86 patients with SVT. They were diagnosed and examined by ultrasonography and blood serum analysis (D-dimer, ANA), and had been followed up every three months.

RESULTS

They had acute SVT in 35 limbs (30%) and chronic SVT in 86 limbs (70%), and they had positive ANA in 63%. They had recurrent SVT in 26%, and all were positive for ANA.

CONCLUSION

ANA-positivity might be a risk factor for acute thrombi in patients with SVT. (*English Translation of J Jpn Coll Angiol 2010; 50: 417-422.).

Venous thromboembolism following microsurgical breast reconstruction: an objective analysis in 225 consecutive patients using low-molecular-weight heparin prophylaxis

BACKGROUND

Free flap breast reconstruction involves major risk factors for postsurgical venous thromboembolism. The main study objectives were (1) to estimate objectively the incidence of symptomatic and asymptomatic lower extremity deep vein thrombosis in patients who received postoperative thromboprophylaxis after free flap breast reconstruction, (2) to evaluate the safety of low-molecular-weight heparin postoperatively, and (3) to assess the incidence of symptomatic pulmonary embolism or sudden death.

METHODS

A cohort study of 225 consecutive patients who underwent abdominally based free flap breast reconstruction at a single cancer center was conducted. The postoperative thromboprophylaxis regimen was based on the American College of Chest Physicians guidelines. A study group of 118 patients systematically underwent bilateral lower extremity duplex ultrasound before hospital discharge to assess objectively the status of the lower extremity deep venous system. A retrospective cohort of 107 women who were not systematically screened for deep vein thrombosis was used for comparison.

RESULTS

The incidence of postoperative deep vein thrombosis confirmed by duplex ultrasound was 3.4 percent in the study group, all events being clinically silent. Bleeding complications in the entire patient sample were estimated at 5.3 percent. Partial flap loss and total flap loss rates were 2.7 and 1.9 percent, respectively. No venous thromboembolism event was diagnosed in the control group.

CONCLUSIONS

This report shows that the objective incidence of deep vein thrombosis was 3.4 percent within 5 postoperative days in this patient population. The authors' findings support the use of triple thromboprophylaxis and demonstrate that low-molecular-weight heparin is a safe and effective method for prevention of venous thromboembolism in this population.

Prolonged thromboprophylaxis with Dalteparin during immobilization after ankle fracture surgery: a randomized placebo-controlled, double-blind study

BACKGROUND

Skeletal trauma and immobilization are well-known risk factors for deep vein thrombosis (DVT) and pulmonary embolism (PE). While prophylaxis against thromboembolic complications has become routine after major orthopedic surgery, whether or not prophylaxis after minor surgery and lower limb immobilization is necessary is still under debate.

METHODS

In a double-blind, placebo-controlled study, 272 consecutive patients were randomized to receive either thromboprophylaxis with Dalteparin (n = 136) or placebo (n = 136) for 5 weeks after ankle fracture surgery. All patients received 1 week of initial treatment with Dalteparin before randomization. A unilateral phlebography was performed when the cast was removed.

RESULTS

The overall incidence of DVT was 21% (95% CI: 13-29%) in the Dalteparin group and 28% (CI: 19- 37%) in the placebo group (risk ratio = 0.8, CI: 0.6-1.1; p = 0.3). The incidence of proximal DVTs was 4% and 3%, respectively. No major bleeding occurred.

INTERPRETATION

We found no significant difference in the incidence of DVT between the 2 treatment groups and our results do not support prolonged thromboprophylaxis. The overall incidence of DVT was high, reflecting the potential risk of PE and post-thrombotic syndrome after ankle fracture surgery. Most of the DVTs were asymptomatic, however, and were located in distal veins.

Short-term and mid-term outcome of isolated symptomatic muscular calf vein thrombosis

BACKGROUND

Although muscular calf vein thrombosis (MCVT) is commonly seen in everyday practice, no treatment guidelines are available. This study evaluated short-term and mid-term outcome of isolated symptomatic MCVT.

METHOD

We included prospectively and consecutively all patients referred to an outpatient clinic with isolated MCVT. Clinical signs were pain or edema, or both, of the calf. Diagnosis was established with duplex ultrasound (DUS) examination. Not completely occlusive and asymptomatic MCVTs were excluded. Patients were followed up clinically and with DUS at 1, 3, and 9 months, and up to 36 months. Anticoagulant therapy at curative dosage associated with compression was prescribed for 1 month and was extended for 2 additional months in case of incomplete recanalization at 1 month or if risk factors for venous thromboembolism (VTE) were present.

RESULTS

Included were 128 patients (78 women, 50 men) presenting with 131 MCVTs. Their mean age was 57.02 +/- 15.36 years (range, 20 to 87 years). Thrombus was present in the soleal veins (SoV) in 73 patients (55.7%) and in the medial gastrocnemius veins (MGV) in 58 (44.3%). Initial symptoms were isolated pain in the calf in 90 patients, isolated edema of the calf in six, and pain plus edema in 32. Anticoagulant therapy was prescribed in 53 patients (41.4%) for 1 month, in 59 (46.1%) for 3 months, and in 13 (10.2%) for >or=6 months. At baseline, nine pulmonary embolisms (7%), complicated with MCVT, were observed in six MGV patients (10.3%) and three SoV patients (4.1%; P = .18). Two nonfatal hemorrhagic events occurred. Three patients died during the follow-up after anticoagulant therapy had been discontinued. Recanalization of MCVT was considered complete at 1, 3, and 9 months in 54.8%, 84.7%, and 96% of cases, respectively, with no significant difference between the MGV and the SoV groups. Twenty-nine VTE symptomatic recurrences (PE, n = 6; DVT including MCVT, n = 23) were observed in 24 patients (18.8%), with similar figures in both thrombosis groups: none at 3 months, 11 between 3 and 9 months and 18 between 9 and 36 months. No extension of the MCVT or a recurrence of VTE was observed in patients treated with anticoagulant therapy. Twelve cases of superficial thrombophlebitis occurred during the follow-up period.

CONCLUSION

This study confirms the place of MCVT in VTE disorders. Pulmonary embolism at the MCVT initial diagnosis was not rare, and mid-term follow-up (mean, 26.7 months) revealed that 18.8% of patients had at least one VTE recurrence. The treatment of acute MCVT needs to be standardized because no guidelines currently exist.

Prolonged thromboprophylaxis with dalteparin after surgical treatment of achilles tendon rupture: a randomized, placebo-controlled study

OBJECTIVES

Prophylaxis against thromboembolic complications has become routine after major orthopedic surgery. In contrast, it remains an issue for debate whether prophylaxis after minor surgery and immobilization is necessary, even though these treatments are well-known risk factors for deep-vein thrombosis (DVT). The objective of this study was to evaluate the efficacy of dalteparin during lower-limb immobilization after surgical treatment of Achilles tendon rupture. DESIGN SETTING, AND PATIENTS: Randomized, placebo-controlled, double-blind study of 105 consecutive patients surgically treated for Achilles tendon rupture in a trauma hospital. DVT screening with color duplex sonography was conducted 3 weeks and 6 weeks after surgery. All DVTs were confirmed with phlebography. Intervention was placebo or dalteparin (5000 U) given subcutaneously once daily for 6 weeks postoperatively.

MAIN OUTCOME MEASURE

DVT incidence.

RESULTS

Primary endpoint analysis was available for 91 patients. DVT was diagnosed in 16 of 47 patients (34%) in the dalteparin group and in 16 of 44 patients (36%) in the placebo group. These figures are not significantly different (P = 0.8). Proximal DVT was diagnosed in 1 patient (2%) in the dalteparin group and in 3 patients (6%) in the placebo group (P = 0.6). No pulmonary emboli or major bleeding occurred in either of the groups.

CONCLUSIONS

DVT is common after surgical treatment of Achilles tendon rupture, and therefore effective thromboprophylaxis is desirable. In our study, thromboprophylaxis with dalteparin, however, does not affect the incidence of DVT during immobilization after Achilles tendon rupture surgery. Long-term effects of immobilization, such as the risk for postthrombotic syndrome, need to be investigated further.

Pilot study on the comprehensive economic costs of major trauma: Consequential costs are well in excess of medical costs

BACKGROUND

Trauma care is expensive. However, reliable data on the exact lifelong costs incurred by a major trauma patient are lacking. Discussion usually focuses on direct medical costs--underestimating consequential costs resulting from absence from work and permanent disability.

METHODS

Direct medical costs and consequential costs of 63 major trauma survivors (ISS >13) at a Swiss trauma center from 1995 to 1996 were assessed 5 years posttrauma. The following cost evaluation methods were used: correction cost method (direct cost of restoring an original state), human capital method (indirect cost of lost productivity), contingent valuation method (human cost as the lost quality of life), and macroeconomic estimates.

RESULTS

Mean ISS (Injury Severity Score) was 26.8 +/- 9.5 (mean +/- SD). In all, 22 patients (35%) were disabled, causing discounted average lifelong total costs of USD 1,293,800, compared with 41 patients (65%) who recovered without any disabilities with incurred costs of USD 147,200 (average of both groups USD 547,800). Two thirds of these costs were attributable to a loss of production whereas only one third was a result of the cost of correction. Primary hospital treatment (USD 27,800 +/- 37,800) was only a minor fraction of the total cost--less than the estimated cost of police and the judiciary. Loss of quality of life led to considerable intangible human costs similar to real costs.

CONCLUSIONS

Trauma costs are commonly underestimated. Direct medical costs make up only a small part of the total costs. Consequential costs, such as lost productivity, are well in excess of the usual medical costs. Mere cost averages give a false estimate of the costs incurred by patients with/without disabilities.

Normal D-dimer concentration is a common finding in symptomatic outpatients with distal deep vein thrombosis

The D-dimer analysis has been shown to have a high sensitivity and a high negative predictive value for the exclusion of deep vein thrombosis (DVT). However, most D-dimer studies, including recent clinical management studies, are performed without examination of the calf veins and/or performed on patient populations with a predominance of proximal DVT. The purpose of this study was to evaluate the diagnostic performance of the D-dimer test in a population with a suspected high incidence of distal DVT. In the present study, 393 outpatients with clinically suspected symptomatic DVT of the lower extremities were examined with whole-leg duplex ultrasonography. The D-dimer analysis was performed using an automated micro-latex assay (Tina-quant). A total of 137 of 393 patients had a proven DVT, with the majority presenting with distal DVT (59%). Twenty-eight out of 81 patients with distal DVT had a normal D-dimer, compared with two of 56 patients with proximal DVT. The sensitivity for distal DVT was only 65% compared with 96% for proximal DVT; the negative predictive values were 84 and 99%, respectively. In conclusion, the prevalence of distal DVT in a study population seems to have a great impact on the diagnostic performance of the D-dimer analysis. The study results also show that normal D-dimer levels do not exclude distal DVT in outpatients; instead, it can be hypothesized that normal D-dimer levels exclude DVT that require treatment, as indicated by the good outcome in recent management studies.

Patent Foramen Ovale and Stroke: Prognosis and Treatment in Young Adults

A patent foramen ovale (PFO) is found with increased frequency in patients with stroke of undetermined origin but the significance and therapeutic implications of this observation remain unclear. Several lines of evidence suggest a role for the PFO in stroke pathophysiology for some cryptogenic stroke patients, such as those whose PFO is accompanied by a prothrombotic state, atrial septal aneurysm, or lower extremity/pelvic DVT. Diagnostic evaluation of the patient with cryptogenic stroke and PFO is directed at identifying these subgroups. Appropriate therapy for primary and secondary stroke prevention in a subject with a PFO remains unclear given current uncertainties as to the pathophysiological significance of PFO. Additional studies are needed, such as those focused on lower extremity veins or the cardiac interatrial septum, to guide therapy in specific stroke subpopulations.

Variation in the diagnostic performance of D-dimer for suspected deep vein thrombosis

BACKGROUND

Numerous studies have evaluated the accuracy of D-dimer in diagnosing suspected deep vein thrombosis (DVT), but results are conflicting.

AIM

To overview estimates of the diagnostic accuracy of D-dimer and identify causes of variation.

DESIGN

Systematic review, meta-analysis and meta-regression.

METHODS

We searched Medline, EMBASE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Reviews of Effectiveness, the ACP Journal Club, citation lists, and contacted manufacturers. We selected studies that compared D-dimer to a reference standard in patients with suspected DVT. Data were analysed by random effects meta-analysis and meta-regression.

RESULTS

We included 97 studies reporting 198 assays in 99 different patient groups. Overall estimated sensitivity and specificity of D-dimer were 90.5% and 54.7%, but both estimates were subject to significant heterogeneity (p < 0.001). Meta-regression identified that some heterogeneity was explained by study setting, exclusion criteria, whether recruitment was consecutive or the study prospective, whether D-dimer and the reference standard were measured blind, and whether the D-dimer threshold was determined a priori. Sensitivity and specificity also varied between ELISA (94% and 45% respectively), latex (89% and 55%) and whole blood agglutination assays (87% and 68%). Sensitivity was higher for proximal than distal DVT. Specificity was dependent upon whether clinical probability of DVT was high (specificity 51%), intermediate (67%) or low (78%).

DISCUSSION

D-dimer has good sensitivity, but poor specificity, for DVT. Estimates are subject to substantial heterogeneity from various sources. D-dimer specificity appears to be strongly dependent upon the pre-test clinical probability of DVT.

Is bilateral duplex scanning necessary in patients with symptoms of deep venous thrombosis?

BACKGROUND

Venous duplex ultrasound scanning (VDUS) has been shown to be an accurate non-invasive means to diagnose symptomatic deep venous thrombosis (DVT). The aim of our study was to determine whether bilateral VDUS is necessary in patients who present with symptoms of DVT.

METHODS

We retrospectively reviewed the results of bilateral lower extremity VDUS performed on 1029 inpatients at Royal Prince Alfred Hospital in the 24 months from 1 January 1998 to 31 December 1999.

RESULTS

Of the 1029 patients, 705 (69%) presented with unilateral symptoms and 324 (31%) with bilateral symptoms. The overall incidence of DVT was 168 (16% of 1029 patients). In 705 patients with unilateral symptoms the diagnosis of DVT was confirmed in 120 (17.0%), of whom 20 (16.7%) had unsuspected bilateral DVT. There were 12 patients (1.7% of the 705 patients) who had DVT in the asymptomatic limb, without DVT identified in the symptomatic limb. Overall there were 32 (5% of 705) patients with unilateral symptoms who had unsuspected DVT in the asymptomatic limb. Of the 20 patients with bilateral DVT, only one patient had more extensive DVT in the asymptomatic limb than in the symptomatic limb, that was therefore likely to alter treatment. Bilateral symptoms of DVT were present in 324 (31.5%) patients, 48 (14.8%) of whom were found to have DVT. Nineteen (39.6%) of these DVTs were bilateral.

CONCLUSION

Overall the diagnostic yield of VDUS was low in this study, with an incidence of 16% of DVT detected in symptomatic patients. Techniques that improve the diagnostic yield of VDUS in symptomatic patients are required. A significant proportion (23%) of the DVT detected in this study were bilateral, and a small but significant proportion (10%) of DVT found in patients presenting with unilateral symptoms were only in the asymptomatic contralateral limb. Our study supports bilateral VDUS in symptomatic inpatients, as the detection of DVT in asymptomatic limbs aids future patient management if symptoms develop in the asymptomatic limb.

[An update on thrombosis prophylaxis in orthopaedic and accident surgery]

The prevention of deep venous thrombosis has become a routine in orthopaedic surgery. While the necessity for prophylaxis is not questioned, its practice is still a matter of controversy. The development of new anticoagulants increases the variety of prophylactic methods but leads to a need for additional information. This review deals with the indications for thrombosis prophylaxis in relation to exposing and predisposing risk factors. The currently available modalities of prophylaxis, their pharmacological details and clinical significance are presented. Evidence based data, recommendations on the duration of prophylaxis derived from official guidelines, issues of the cost/effectiveness, and medico-judicial aspects are discussed.

Calf deep venous thrombosis should be treated with anticoagulation

A 50-year-old man with hypertension presents with a 2-day history of right calf swelling and pain. Venous duplex ultrasound reveals a right soleal vein thrombosis. He denies history of bleeding, renal disease, and symptoms suggestive of pulmonary embolism (PE). Physical examination is unrevealing except for calf tenderness, redness, warmth, and swelling. He is ambulatory. A decision is made to treat the calf deep venous thrombosis (DVT) with anticoagulation.