A 16-year haemodynamic follow-up of women with pregnancy-related medically treated iliofemoral deep venous thrombosis

A systematic review on long-term clinical impact in patients with iliofemoral deep vein thrombosis

OBJECTIVE

The aim of this systematic review was to investigate the long-term clinical impact of iliofemoral (IF) deep vein thrombosis (DVT) based on patient reported outcomes, physician administered test measures and compare medical to interventional treatment.

METHODS

This study was conducted according to the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. Criteria for inclusion were patients with thrombus involving the common femoral vein or more proximal veins, ≥5-year follow-up and physician assessment. Data quality was assessed using the Robins-I tool and Cochrane tool.

RESULTS

Eight studies that fulfilled our criteria were deemed eligible and provided data for 499 patients. There were 230 patients who received medical treatment and 269 interventional. Two studies were randomized controlled trials and six observational. Venous claudication, where reported, was found in 7.7% (1/13) of interventionally treated patients and 21% (13/62) of medically treated patients. Long term symptom resolution was reported in 58% (18/31) and 24% (12/50) of interventionally and medically treated patients, respectively. Venous ulcers were seen in 5.5% (7/126) of medically treated patients and 5% (5/100)of interventionally treated patients.

CONCLUSION

A wide range of signs and symptoms was reported at long-term. Interventional treatment appeared to be better than medical one but the evidence was weak. Given the significant lack of patient reported outcomes, objective testing and use of validated instruments, the results should be interpreted in context with these limitations. Data on long-term outcomes after IF DVT have been poorly reported and outcome criteria should be better defined in future studies.

Pulmonary Embolism in Pregnancy

Even though venous thromboembolism is a leading cause of maternal mortality in high-income countries, there are limited high-quality data to assist clinicians with the management of pulmonary embolism in this patient population. Diagnosis, prevention, and treatment of pregnancy-associated pulmonary embolism are complicated by the need to consider fetal, as well as maternal, well-being. Recent studies suggest that clinical prediction rules and D-dimer testing can reduce the need for diagnostic imaging in a subset of patients. Low-molecular-weight heparin is the preferred anticoagulant for both prophylaxis and treatment in this setting. Direct oral anticoagulants are contraindicated during pregnancy and in breastfeeding women. Thrombolysis or embolectomy should be considered for pregnant women with pulmonary embolism complicated by hemodynamic instability. Treatment of pregnancy-associated pulmonary embolism should be continued for at least 3 months, including 6 weeks postpartum. Management of anticoagulants at the time of delivery should involve a multidisciplinary individualized approach that uses shared decision making to take patient and caregiver values and preferences into account.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: venous thromboembolism in the context of pregnancy

BACKGROUND

Venous thromboembolism (VTE) complicates ∼1.2 of every 1000 deliveries. Despite these low absolute risks, pregnancy-associated VTE is a leading cause of maternal morbidity and mortality.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians and others in decisions about the prevention and management of pregnancy-associated VTE.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

The panel agreed on 31 recommendations related to the treatment of VTE and superficial vein thrombosis, diagnosis of VTE, and thrombosis prophylaxis.

CONCLUSIONS

There was a strong recommendation for low-molecular-weight heparin (LWMH) over unfractionated heparin for acute VTE. Most recommendations were conditional, including those for either twice-per-day or once-per-day LMWH dosing for the treatment of acute VTE and initial outpatient therapy over hospital admission with low-risk acute VTE, as well as against routine anti-factor Xa (FXa) monitoring to guide dosing with LMWH for VTE treatment. There was a strong recommendation (low certainty in evidence) for antepartum anticoagulant prophylaxis with a history of unprovoked or hormonally associated VTE and a conditional recommendation against antepartum anticoagulant prophylaxis with prior VTE associated with a resolved nonhormonal provoking risk factor.

A comparison of magnetic resonance venography findings and venous occlusion plethysmography variables in postthrombotic syndrome

Objective The relation between venous morphology and venous function in postthrombotic syndrome is poorly understood. The aim of this study was to compare obstruction and collateralization as seen with magnetic resonance venography with variables of venous occlusion plethysmography in patients with postthrombotic syndrome. Methods Medical records, magnetic resonance venography and venous occlusion plethysmography data were analyzed in 28 patients (33 legs). Magnetic resonance venography images were scored for degree of obstruction and collateralization in segments of pelvic and abdominal veins and correlated to venous occlusion plethysmography data. Results Obstruction of the inferior vena cava correlated with an overall increase of collaterals ( p < 0.001). The summary scores of collaterals or obstructions did not correlate with venous occlusion plethysmography variables. Relative expelled volume at 4 s correlated inversely with obstruction of the inferior vena cava ( p = 0.045) and vertebral collateralization ( p = 0.033). Conclusions Modest correlations were found between magnetic resonance venography scores and venous occlusion plethysmography variables. Prospective studies with refined scoring and magnetic resonance venography techniques may increase our knowledge further.

Inferior vena cava filters

Use of inferior vena cava (IVC) filters has increased dramatically in recent decades, despite a lack of evidence that their use has impacted venous thromboembolism (VTE)-related mortality. This increased use appears to be primarily driven by the insertion of retrievable filters for prophylactic indications. A growing body of evidence, however, suggests that IVC filters are frequently associated with clinically important adverse events, prompting a closer look at their role. We sought to narratively review the current evidence on the efficacy and safety of IVC filter placements. Inferior vena cava filters remain the only treatment option for patients with an acute (within 2-4 weeks) proximal deep vein thrombosis (DVT) or pulmonary embolism and an absolute contraindication to anticoagulation. In such patients, anticoagulation should be resumed and IVC filters removed as soon as the contraindication has passed. For all other indications, there is insufficient evidence to support the use of IVC filters and high-quality trials are required. In patients where an IVC filter remains, regular follow-up to reassess removal and screen for filter-related complications should occur.

Hereditary risk factors for thrombophilia and probability of venous thromboembolism during pregnancy and the puerperium

Venous thromboembolism (VTE) is a leading cause of maternal mortality. Few studies have evaluated the individual risk of gestational VTE associated with heritable thrombophilia, and current recommendations for antenatal thromboprophylaxis in women with severe thrombophilia such as homozygous factor V Leiden mutation (FVL) depend on a positive family history of VTE. To better stratify thromboprophylaxis in pregnancy, we aimed to estimate the individual probability (absolute risk) of gestational VTE associated with thrombophilia and to see whether these risk factors are independent of a family history of VTE in first-degree relatives. We studied 243 women with the first VTE during pregnancy and the puerperium and 243 age-matched normal women. Baseline incidence of VTE of 1:483 pregnancies in women ≥35 years and 1:741 deliveries in women <35 years was assumed, according to a recent population-based study. In women ≥35 years (<35 years), the individual probability of gestational VTE was as follows: 0.7% (0.5%) for heterozygous FVL; 3.4% (2.2%) for homozygous FVL; 0.6% (0.4%) for heterozygous prothrombin G20210A; 8.2% (5.5%) for compound heterozygotes for FVL and prothrombin G20210A; 9.0% (6.1%) for antithrombin deficiency; 1.1% (0.7%) for protein C deficiency; and 1.0% (0.7%) for protein S deficiency. These results were independent of a positive family history of VTE. We provide evidence that unselected women with these thrombophilias have an increased risk of gestational VTE independent of a positive family history of VTE. In contrast to current guidelines, these data suggest that women with high-risk thrombophilia should be considered for antenatal thromboprophylaxis regardless of family history of VTE.

Recurrence of venous thromboembolism in patients with recent gestational deep vein thrombosis or pulmonary embolism: Findings from the RIETE Registry

INTRODUCTION

The aim of this study was to investigate the recurrence rate of venous thromboembolism (VTE) and the prevalence of major bleeding or death in patients with previous VTE in pregnancy and puerperium. Risk factors for VTE recurrence were also assessed.

MATERIALS AND METHODS

We evaluated a cohort of patients enrolled in the international, multicenter, prospective Registro Informatizado de la Enfermedad Trombo-Embólica (RIETE) registry with objectively confirmed VTE.

RESULTS

In the registry, 607 women were presenting with VTE that occurred during pregnancy or puerperium. The 2-year VTE recurrence rate was 3.3% (CI: 95 1.5-5.0%) and the recurrent VTE incidence rate was 2.28events/100 patients-year. Among the 16 cases of VTE recurrence 11 cases appeared during drug treatment while only five cases were diagnosed after therapy discontinuation. No significant difference was found in treatment duration among these two subgroups of VTE recurrence cases and women without recurrence. Furthermore, the use of thrombolytics and inferior vena cava filter in initial treatment was associated to an increased risk of VTE recurrence.

CONCLUSIONS

The current study provides new insights on VTE recurrence rate in patients with deep vein thrombosis (DVT) or pulmonary embolism (PE) that occurred in pregnancy or postpartum period. These findings can contribute to risk assessment of thrombotic burden, thereby allowing for better decision making regarding antithrombotic management in this clinical setting.

Analysis of 1,338 Patients with Acute Lower Limb Deep Venous Thrombosis (DVT) Supports the Inadequacy of the Term "Proximal DVT"

OBJECTIVE/BACKGROUND

For decades acute lower limb deep venous thrombosis (DVT) has been subdivided into distal DVT (isolated to the calf veins) and proximal DVT (extending above calf vein level). The aim of this study was to analyse the anatomical site and extent of thrombus in a large cohort of patients with acute DVT.

METHODS

A retrospective analysis of all patients aged >18 years, presenting with unilateral DVT according to duplex ultrasound investigation was performed at the University Hospital of Antwerp, Belgium (1994-2012). The anatomical site and extent of thrombus was registered and subdivided into five segments: calf veins (segment 1), popliteal vein (segment 2), femoral vein (segment 3), common femoral vein (segment 4), and iliac veins, with or without inferior vena cava (segment 5).

RESULTS

The median age of the 1,338 patients (50% male) included was 62 years (range 18-98 years). Left sided DVT was predominant (57%). DVT was limited to one segment in 443 patients, of whom 370 had DVT isolated to the calf veins (28% of total cohort). In 968 patients with what was previously called "proximal DVT", the median number of affected segments was three (range 1-5 segments). In this group iliofemoral DVT (at least involving segment four and/or five) was present in 506 patients (38% of total cohort), whereas the remaining patients had femoropopliteal DVT (at least in segment two and/or three but not in four or five). Iliofemoral DVT without thrombus in segments one and two was present in 160 patients (12% of total cohort).

CONCLUSION

This study illustrates the large diversity of thrombus distribution in patients previously described as having "proximal DVT". Therefore, this term should be abandoned and replaced with iliofemoral and femoropopliteal DVT. Patients with iliofemoral DVT (38%) could be considered for early clot removal; 12% of all patients with DVT would be ideal candidates for such intervention.

Guidance for the treatment and prevention of obstetric-associated venous thromboembolism

Venous thromboembolism (VTE), which may manifest as pulmonary embolism (PE) or deep vein thrombosis (DVT), is a serious and potentially fatal condition. Treatment and prevention of obstetric-related VTE is complicated by the need to consider fetal, as well as maternal, wellbeing when making management decisions. Although absolute VTE rates in this population are low, obstetric-associated VTE is an important cause of maternal morbidity and mortality. This manuscript, initiated by the Anticoagulation Forum, provides practical clinical guidance on the prevention and treatment of obstetric-associated VTE based on existing guidelines and consensus expert opinion based on available literature where guidelines are lacking.

Computerized venous strain-gauge plethysmography is a reliable method for measuring venous function

OBJECTIVES

To achieve reference values for computerized strain-gauge plethysmography (SGP), to assess reproducibility, and to evaluate the influence of different factors such as age, gender, body mass index, and symptomatic post-thrombotic disease on commonly used variables.

METHODS

Sixty-three healthy controls and 56 patients with previous deep venous thrombosis (DVT) were included. All participants underwent computerized SGP with evaluation of outflow capacity, as well as evaluation of venous reflux and muscle pump function.

RESULTS

All variables were significantly reduced in DVT limbs, both compared with contralateral limbs and with healthy controls. Only two patients had all values within normal ranges (=mean ± 2 SD in controls). Measures of outflow capacity had a coefficient of variation (CV) of 5-6% and exercise-induced volume changes a CV of 10-15%. In symptomatic post-thrombotic limbs half-refilling time was significantly related to presence of edema (R = -0.28, p < .05) and to chronic skin changes (R = -0.58, p < .001).

CONCLUSIONS

We suggest that our values in healthy controls can be used as new reference values for computerized venous strain-gauge plethysmography. The computerized design ensures high reproducibility and the results indicate that this is a very useful and sensitive test for functional quantitative assessment of patients with venous disease.

Venous thromboembolism in women: a specific reproductive health risk

BACKGROUND Venous thromboembolism (VTE) is a specific reproductive health risk for women. METHODS Searches were performed in Medline and other databases. The selection criteria were high-quality studies and studies relevant to clinical reproductive medicine. Summaries were presented and discussed by the European Society of Human Reproduction and Embryology Workshop Group. RESULTS VTE is a multifactorial disease with a baseline annual incidence around 50 per 100 000 at 25 years and 120 per 100 000 at age 50. Its major complication is pulmonary embolism, causing death in 1-2% of patients. Higher VTE risk is associated with an inherited thrombophilia in men and women. Changes in the coagulation system and in the risk of clinical VTE in women also occur during pregnancy, with the use of reproductive hormones and as a consequence of ovarian stimulation when hyperstimulation syndrome and conception occur together. In pregnancy, the risk of VTE is increased ~5-fold, while the use of combined hormonal contraception (CHC) doubles the risk and this relative risk is higher with the more recent pills containing desogestrel, gestodene and drospirenone when compared with those with levonorgestrel. Similarly, hormone replacement therapy (HRT) increases the VTE risk 2- to 4-fold. There is a synergistic effect between thrombophilia and the various reproductive risks. Prevention of VTE during pregnancy should be offered to women with specific risk factors. In women who are at high risk, CHC and HRT should be avoided. CONCLUSIONS Clinicians managing pregnancy or treating women for infertility or prescribing CHC and HRT should be aware of the increased risks of VTE and the need to take a careful medical history to identify additional co-existing risks, and should be able to diagnose VTE and know how to approach its prevention.

Thrombosis in women: what are the knowledge gaps in 2013?

Several aspects of the diagnostic and therapeutic management of women with venous thrombosis are uncertain. In this overview, I will discuss three major areas. First, the contribution of hormone use to venous thromboembolism (VTE) will be discussed as prudent prescribing of safe preparations can further reduce the risk of hormone-related VTE. Uncertainties remain regarding certain low-dose progestagens and transdermal routing of hormones and their associated risk of VTE. Second, I will review the diagnosis, treatment, and prevention of pregnancy-related VTE. As direct evidence is largely absent for these individuals, these areas are subject to extrapolation from the non-pregnant population. There is therefore an urgent need for the evaluation of diagnostic strategies that safely exclude the diagnosis of acute pulmonary embolism in pregnant women without the need for diagnostic imaging, which is currently the gold standard, as no studies have confidently demonstrated the safety of ruling out VTE by clinical probability assessment combined with the use of D-dimer levels. Although identification of women at increased risk of pregnancy-related VTE is relatively well established, controversy remains for asymptomatic women from thrombophilic families. The optimal duration and intensity of anticoagulant treatment for, and prophylaxis of, pregnancy-related VTE with low molecular weight heparin is unknown. Third, anticoagulant therapy to prevent recurrence in women with unexplained recurrent miscarriage has shown to have no benefit and should not be prescribed. However, whether antithrombotic therapy prevents recurrent miscarriage in thrombophilic women, or in women with severe pregnancy complications, remains unknown and urgently requires future research.

Venous occlusion plethysmography in patients with post-thrombotic venous claudication

OBJECTIVE

Post-thrombotic venous claudication is a serious condition that may be treated with iliac vein stenting or open surgery, and there is a need for hemodynamic tests in the preoperative evaluation. The purpose of this study was to describe the results of venous occlusion plethysmography in patients with venous claudication and to analyze the outflow curve to find variables that best describe the functional abnormality in this patient group.

METHODS

Twenty-nine patients with previous deep venous thrombosis and with clinical evidence of venous claudication were retrospectively identified. The results of venous occlusion plethysmography in these patients were compared with results obtained in a group of 63 healthy control subjects of similar age and sex. Computerized strain-gauge plethysmography was used in a capacitance mode where the occlusion time is determined by an electronic detector allowing the maximal venous volume to be achieved in all limbs. Outflow volumes (OV1, OV4) and outflow fractions (OF1, OF4) were calculated at 1 and 4 seconds after cuff release. Outflow fraction is OV divided by maximal venous volume.

RESULTS

Both outflow volumes and outflow fractions were significantly reduced in patients compared with healthy control subjects. Outflow fractions were more sensitive than outflow volumes in identifying patients with venous claudication. The most discriminating variable was OF4 that was reduced below the normal lower limit in 69% of the patients, most severely reduced in patients with severe claudication.

CONCLUSIONS

Patients with venous claudication attributable to remaining post-thrombotic iliofemoral obstructive disease are characterized by a functional disturbance shown with venous occlusion plethysmography as a reduced venous outflow during the initial 4 seconds following cuff release in relation to their true maximal venous volume. Our results suggest that venous occlusion plethysmography can be a valuable tool in the preoperative workup for selection of patients with iliofemoral vein obstruction that may benefit from venous intervention.

Early diagnosis of iliofemoral DVT in pregnancy in the emergency department

The case of a 26-year-old woman who was 23 weeks pregnant is described; the patient presented, on a weekend, to the emergency department (ED) with left groin pain. There were few clinical signs of deep venous thrombosis (DVT) but ED ultrasound (US) showed a left external iliac vein thrombus. This is a new technique in the ED. Not only does this case show the importance of using this technique in the ED, but it also shows the importance of correct training in how to examine for thrombus in the external iliac vein in the pregnant patient. The patient was admitted to the hospital and started on low-molecular-weight heparin. A formal radiology department US performed the next week confirmed the diagnosis of DVT.

Prevalence and predictors for post-thrombotic syndrome 3 to 16 years after pregnancy-related venous thrombosis: a population-based, cross-sectional, case-control study

BACKGROUND

The long-term outcome of pregnancy-related venous thrombosis (VT) is not known.

OBJECTIVES

To assess predictors and long-term frequency of post-thrombotic syndrome (PTS) after pregnancy-related VT.

PATIENTS/METHODS

In 2006, 313 women with pregnancy-related VT during 1990-2003 and 353 controls answered a comprehensive questionnaire that included self-reported Villalta score as a measure of PTS. Cases were identified from 18 Norwegian hospitals using the Norwegian Patient Registry and the Medical Birth Registry of Norway. The latter was used to select as possible controls women who gave birth at the same time as a case. Thirty-nine patients and four controls were excluded because of VT outside the lower limbs/lungs or missing Villalta scores. Two hundred and four patients had DVT in the lower limb and 70 had pulmonary embolism (PE). The control group comprised 349 women naive for VT at the time of the index pregnancy.

RESULTS

Forty-two per cent of cases with DVT in the lower limb, compared with 24% of cases with PE and 10% of controls, reported a Villalta score of ≥ 5. Severe PTS (Villalta score of ≥ 15) was reported among 7%, 4% and 1%. Proximal postnatal, but not antenatal, thrombosis was a strong predictor of PTS with an adjusted odds ratio of 6.3 (95% confidence interval, 2.0-19.8; P = 0.002). Daily smoking before the index pregnancy and age above 33 years at event were independent predictors for post-thrombotic syndrome.

CONCLUSIONS

PTS is a common long-term complication after pregnancy-related DVT. Proximal postnatal thrombosis, smoking and higher age were independent predictors of the development of PTS.

Pregnancy-associated venous thromboembolism: prevention and treatment

Pregnancy is associated with an increased risk of venous thromboembolism (VTE) and this condition remains an important cause of maternal morbidity and mortality. The use of anticoagulant therapy for treatment and prophylaxis of VTE during pregnancy is challenging because of the potential for fetal, as well as maternal, complications. Although evidence-based recommendations for the use of anticoagulants have been published, given the paucity of available data, guidelines are based largely upon observational studies and from data in nonpregnant patients. This article reviews the available literature and provides guidance for the management and prevention of VTE during pregnancy.

VTE, thrombophilia, antithrombotic therapy, and pregnancy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

The use of anticoagulant therapy during pregnancy is challenging because of the potential for both fetal and maternal complications. This guideline focuses on the management of VTE and thrombophilia as well as the use of antithrombotic agents during pregnancy.

METHODS

The methods of this guideline follow the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

We recommend low-molecular-weight heparin for the prevention and treatment of VTE in pregnant women instead of unfractionated heparin (Grade 1B). For pregnant women with acute VTE, we suggest that anticoagulants be continued for at least 6 weeks postpartum (for a minimum duration of therapy of 3 months) compared with shorter durations of treatment (Grade 2C). For women who fulfill the laboratory criteria for antiphospholipid antibody (APLA) syndrome and meet the clinical APLA criteria based on a history of three or more pregnancy losses, we recommend antepartum administration of prophylactic or intermediate-dose unfractionated heparin or prophylactic low-molecular-weight heparin combined with low-dose aspirin (75-100 mg/d) over no treatment (Grade 1B). For women with inherited thrombophilia and a history of pregnancy complications, we suggest not to use antithrombotic prophylaxis (Grade 2C). For women with two or more miscarriages but without APLA or thrombophilia, we recommend against antithrombotic prophylaxis (Grade 1B).

CONCLUSIONS

Most recommendations in this guideline are based on observational studies and extrapolation from other populations. There is an urgent need for appropriately designed studies in this population.

Obstetric thromboprophylaxis: the Swedish guidelines

Obstetric thromboprophylaxis is difficult. Since 10 years Swedish obstetricians have used a combined risk estimation model and recommendations concerning to whom, at what dose, when, and for how long thromboprophylaxis is to be administrated based on a weighted risk score. In this paper we describe the background and validation of the Swedish guidelines for obstetric thromboprophylaxis in women with moderate-high risk of VTE, that is, at similar or higher risk as the antepartum risk among women with history of thrombosis. The risk score is based on major risk factors (i.e., 5-fold increased risk of thromboembolism). We present data on the efficacy of the model, the cost-effectiveness, and the lifestyle advice that is given. We believe that the Swedish guidelines for obstetric thromboprophylaxis aid clinicians in providing women at increased risk of VTE with effective and appropriate thromboprophylaxis, thus avoiding both over- and under-treatment.

How I treat pregnancy-related venous thromboembolism

Venous thromboembolism (VTE) complicates ∼ 1 to 2 of 1000 pregnancies, with pulmonary embolism being a leading cause of maternal mortality and deep vein thrombosis an important cause of maternal morbidity, also on the long term. However, a strong evidence base for the management of pregnancy-related VTE is missing. Management is not standardized between physicians, centers, and countries. The management of pregnancy-related VTE is based on extrapolation from the nonpregnant population, and clinical trial data for the optimal treatment are not available. Low-molecular-weight heparin (LMWH) in therapeutic doses is the treatment of choice during pregnancy, and anticoagulation (LMWH or vitamin K antagonists postpartum) should be continued until 6 weeks after delivery with a minimum total duration of 3 months. Use of LMWH or vitamin K antagonists does not preclude breastfeeding. Whether dosing should be based on weight or anti-Xa levels is unknown, and practices differ between centers. Management of delivery, including the type of anesthesia if deemed necessary, requires a multidisciplinary approach, and several options are possible, depending on local preferences and patient-specific conditions.

Recommendations for the prevention of pregnancy-associated venous thromboembolism

Pregnancy is a risk factor for venous thromboembolism (VTE), an important cause of maternal morbidity and mortality. Although there is a 4-5-fold increased risk compared to that of nonpregnant women of the same age, the absolute risk is low at no more than two episodes of VTE per 1000 pregnancies. There is uncertainty about which women require thromboprophylaxis during pregnancy or postpartum because of a lack of data from appropriate clinical trials. For this reason, recommendations for prophylaxis should be made only after explaining the available evidence to the patient and taking into account her perception of the balance of risk and benefit in thromboprophylaxis. The aim of these recommendations is to provide clinicians with practical advice to assist in decisions regarding thromboprophylaxis in women considered to be at risk of VTE during pregnancy and the postpartum. The authors are clinicians from across New Zealand and Australia representing the fields of haematology, obstetric medicine, anaesthesiology, maternal-fetal medicine and obstetrics. Authors were invited to review the relevant literature and then worked collaboratively to devise recommendations and resolve areas of controversy. The recommendations contained herein were reached by consensus and represent the opinion of the panel. The absence of randomised clinical trials in this area limits the strength of evidence that can be used, and it is acknowledged that they represent level C evidence. The panel advocates for appropriate clinical studies to be carried out in this patient population to address the inadequacy of present evidence.

Deep venous thrombosis after surgery for Achilles tendon rupture: a provoked transient event with minor long-term sequelae

BACKGROUND

Deep venous thrombosis (DVT) occurs frequently in patients undergoing orthopedic surgery, but there is a lack of knowledge regarding long-term sequelae of DVT after different types of surgical procedures.

OBJECTIVE

To describe the long-term effect of symptomatic (SDVT) and asymptomatic (ADVT) deep venous thrombosis on venous function and subsequent incidence of post-thrombotic syndrome (PTS) in patients who have undergone surgery for Achilles tendon rupture.

PATIENTS/METHODS

This observational follow-up study includes 83 patients with postoperative DVT, examined after a mean of 7 years. There were two series of patients: 45 with SDVT and 38 with ADVT. In both series, more than 90% of the DVTs were limited to calf veins. Follow-up examinations comprised color duplex ultrasonography (CDU), strain-gauge plethysmography (SGP), clinical examination including scoring for venous disease and questionnaires for quality of life (QOL).

RESULTS

A mild degree of PTS was found in 11% of the patients: 13% in SDVT and 8% in ADVT patients. The rate of recurrent ipsilateral DVT was 2%. Deep venous reflux was more common in patients with SDVT than in ADVT patients (84% vs. 55%, P < 0.01). Only a few patients had plethysmograpically abnormal findings without difference between the two groups.

CONCLUSION

DVT after surgery for Achilles tendon rupture consists mainly of distal DVTs and are associated with a low risk for PTS. Deep venous reflux was more common in SDVT than in ADVT patients, probably as an effect of larger DVTs in the former group.

A follow-up study of the fate of small asymptomatic deep venous thromboses

Background

Postoperative asymptomatic deep venous thromboses (ADVT) can give rise to posttthrombotic syndrome (PTS), but there are still many unresolved issues in this context. For example, there is a lack of knowledge regarding the fate of small ADVT following minor orthopedic surgery. This follow-up study evaluates postthrombotic changes and clinical manifestations of PTS in a group of patients with asymptomatic calf vein DVT after surgery for Achilles tendon rupture.

Methods

Forty-six consecutive patients with distal ADVT were contacted and enrolled in a follow-up consisting of a single visit at the hospital at a mean time of 5 years postoperatively, including clinical examination and scoring, ultrasonography and venous plethysmography. All patients had participated in DVT-screening with colour duplex ultrasound (CDU) 3 and 6 weeks postoperatively and 80% of them were treated with anticoagulation.

Results

With CDU postthrombotic changes and deep venous reflux were detected at follow-up in more than 50% of the patients, more commonly in somewhat larger calf DVT:s initially affecting more than one vessel. However, only about 10% of the patients had significant venous reflux according to venous plethysmography. No patient had plethysmographic evidence of remaining outflow obstruction, but presence of postthrombotic changes shown with CDU negatively influenced venous outflow capacity measured with plethysmography. A clinical entity of PTS was rarely found and occurred only in two patients (4%) and then classified by Villalta scoring as of mild degree with few clinical signs of disease. Distal ADVT:s detected in the early postoperative period (3 weeks) showed DVT-progression in 75% of the limbs that were still immobilized and without anticoagulation.

Conclusions

Asymptomatic postoperative distal DVT:s following surgery for Achilles tendon rupture have a good prognosis and a favourable clinical outcome. In our material of 46 patients the general appearance of the clinical entity of PTS at 5 years follow-up was low (<5%). Morphological and functional abnormalities were mainly seen in those patients that initially had somewhat larger distal DVT:s involving more than one deep calf vein segment.

Asymptomatic deep venous thrombosis is associated with a low risk of post-thrombotic syndrome

Post-thrombotic syndrome (PTS) is a well-recognized condition that develops after symptomatic deep venous thrombosis, but the clinical significance and late complications of asymptomatic deep venous thrombosis (ADVT) are unclear.

OBJECTIVE

To determine whether ADVT following minor surgery affects venous function and contributes to the later development of PTS.

PATIENTS/METHODS

The study included 83 patients operated on for Achilles tendon rupture; 38 patients with postoperative ADVT and 45 patients without (control group). The follow-up examinations five years after the operation comprised computerised strain-gauge plethysmography, colour duplex ultrasonography, clinical scoring of venous disease, and quality of life (QOL).

RESULTS

Villalta scores, CEAP classification and QOL did not differ between groups. PTS (=Villalta score > or =5) was found in three ADVT patients (8%) and in two controls (4%). Ultrasonography revealed post-thrombotic changes in 55% of ADVT patients and in none of the controls. Deep venous reflux occurred in 22 ADVT patients and in three controls (P<0.001). There was no difference between groups in plethysmographic variables, demonstrating that the ultrasonographic abnormalities were of negligible haemodynamic significance.

CONCLUSIONS

PTS is not a common sequel to ADVT after minor surgery. Although more than 50% of patients with ADVT developed post-thrombotic changes according to ultrasound, these changes did not result in haemodynamically significant venous dysfunction.

Prevention and management of venous thromboembolism in pregnancy

Normal pregnancy is accompanied by an increase in clotting factors. The resulting hypercoagulable state has likely evolved to protect women from hemorrhage at the time of miscarriage and childbirth. During pregnancy, women are 4 times more likely to suffer from venous thromboembolism (VTE) compared with when they are not pregnant. Relative to pregnancy, the risk postpartum is even higher. The incidence of VTE is approximately 2 per 1,000 births, and VTE accounts for 1 death per 100,000 births, or approximately 10% of all maternal deaths. The most important risk factors during pregnancy are thrombophilia and a history of thrombosis. A history of thrombosis increases the risk for VTE to 2% to 12%. Thrombophilia increases not only the risk for maternal thrombosis but also the risk of poor pregnancy outcome. Despite the increased risk for thrombosis during pregnancy and the postpartum period, most women do not require anticoagulation. Those who do require anticoagulation include women with current VTE, women on lifelong anticoagulation, and many women with thrombophilia or a history of thrombosis. Recommended options for anticoagulation in pregnancy are limited to heparins, which do not cross the placenta. Low-molecular-weight heparin (LMWH) is preferred over unfractionated heparin because LMWH has a longer half-life and is presumed to have fewer side effects. The longer half-life is a disadvantage around the time of delivery, when unfractionated heparin, with its shorter half-life, is easier to manage. For women who develop or are at high risk for heparin-induced thrombocytopenia or severe cutaneous reactions, fondaparinux is probably the agent of choice. Women who do not require lifelong anticoagulation, but require anticoagulation during pregnancy, will still require anticoagulation for the first 6 weeks postpartum.

Hemodynamic and morphologic evaluation of sequelae of primary upper extremity deep venous thromboses treated with anticoagulation

OBJECTIVES

This study was performed to describe venous function, residual morphologic abnormalities, and the occurrence of post-thrombotic syndrome in patients with conservatively treated primary upper-extremity deep venous thromboses (UEDVT).

METHOD

This was a retrospective follow-up study of 31 patients with previous primary UEDVT treated with anticoagulation only, identified by a search of medical records. The mean follow-up time was 5 years. The patients were evaluated by interview, clinical examination, computerized strain-gauge plethysmography, and color duplex ultrasound imaging. The grade of post-thrombotic syndrome was rated according to the Villalta score (0 to 3 on each of four subjective and five clinically assessed features).

RESULTS

The rate of venous emptying was significantly lower in the arms with DVTs than in the contralateral arms (P < .001). Eleven of the patients (35%) had a remaining outflow obstruction in the affected arm (venous emptying <68 mL/100 mL per min). Eighteen (58%) had a residual thrombus according to color duplex ultrasound scans, with four remaining occluded subclavian veins. None of the patients had deep or superficial venous reflux. There was no statistically significant relationship between plethysmographic and duplex findings. Most (77%) of the patients reported remaining symptoms in the affected arm, and there was a significant side difference in upper arm circumference (P < .001). Approximately one third had developed a moderate grade of post-thrombotic syndrome according to the Villalta score (total, 5 to 9). No significant relation was evident between the post-thrombotic syndrome score and duplex findings. Patients with post-thrombotic syndrome had a lower venous emptying value than those without (69 vs 84 mL/100 mL per min), but this difference was not statistically significant.

CONCLUSIONS

Patients with conservatively treated previous primary UEDVT had significantly reduced venous outflow capacity and a residual thrombus was common. Swelling of the arm was the most common symptom, and one third had a moderate grade of post-thrombotic syndrome. However, there was no clear relation between hemodynamic and morphologic factors and the development of post-thrombotic syndrome in these 31 patients, examined at a mean of 5 years after an acute DVT episode.

A methodological study of computerized venous strain-gauge plethysmography of the upper extremities

This study was performed to assess the efficiency of computerized strain-gauge plethysmography for evaluation of venous volume (VV) and outflow capacity of the upper extremities and to receive reference values. For this purpose, we investigated 34 healthy controls; 16 males and 18 females with a mean age of 45 years (range 31-58 years). These results were compared with those obtained in 32 patients with earlier spontaneous deep venous thrombosis (DVT) in the upper extremities. In the control group, there was no difference between right and left arm and none of the variables were influenced by age and gender. Venous volume and rate of venous emptying (VE) were significantly lower in arms with earlier DVT than in those without (VV: DVT arms 3.7+/-0.96 ml 100ml-1 and controls 4.6+/-0.81 ml 100 ml-1; VE: DVT arms 79+/-24 ml 100 ml-1 min-1 and controls 110+/-21 ml 100 ml-1 min-1). Repeated measurements had a coefficient of variation of approximately 10% in both groups. We found the device easy to handle and the results demonstrates that this is a useful method to study venous function in upper extremities. This implicates that computerized strain-gauge plethysmography is an efficient method both for clinical diagnostic routine and research studies of circulatory changes in acute and chronic DVT in the upper extremity.

Preservation of Venous Valve Function after Catheter-Directed and Systemic Thrombolysis for Deep Venous Thrombosis

OBJECTIVES

The aim of the study was to assess venous reflux and the obstruction pattern after catheter-directed and systemic thrombolysis of deep iliofemoral venous thrombosis.

PATIENTS

Thirty-two patients treated either with systemic (16) or catheter-directed local thrombolysis (16) for massive iliofemoral thrombosis were identified from the hospital registry.

METHODS

Clinical evaluation at follow up was based on the CEAP classification and disability score. Reflux was assessed by colour duplex ultrasonography and standardised reflux testing. A vascular surgeon blinded to treatment established the clinical status of the lower limb following the previous DVT.

RESULTS

Valvular competence was preserved in 44% of patients treated with catheter-directed thrombolysis compared with 13% of those treated with systemic thrombolysis (p=0.049, Chi squared). Reflux in any deep vein was present in 44% of patients treated by catheter-directed lysis compared with 81% of patients receiving systemic thrombolysis (p=0.03, Chi squared). Reflux in any superficial vein was observed in 25% vs. 63% of the patients, respectively (p=0.03, Chi squared). There were significantly more patients with venous insufficiency of classes C0-1 in the group treated with catheter-directed thrombolysis.

CONCLUSION

In this clinical series venous valvular function was better preserved after iliofemoral DVT when treated with catheter-directed thrombolysis.

Young patients with iliofemoral deep venous thrombosis should receive thrombolytic therapy

A 20-year-old otherwise healthy woman on oral contraceptive pills presents with sudden-onset left leg swelling and pain extending from her calf to her groin. Pulmonary embolism symptoms are lacking. Venous duplex ultrasound reveals acute deep venous thrombosis (DVT) involving the distal external iliac, common femoral, superficial femoral, and popliteal veins. Her leg is markedly swollen, slightly cool to the touch, but has preserved pedal pulses. She is unable to ambulate secondary to pain. Thrombolytic therapy to eliminate the DVT is recommended.