Duplex ultrasound in the hemodynamic evaluation of the late sequelae of deep venous thrombosis

Home Therapy With LMWH in Deep Vein Thrombosis: Randomized Study Comparing Single and Double Daily Administrations

The aim of this study was to assess the effectiveness of low-molecular-weight heparin (LMWH) treatment of deep vein thrombosis (DVT) in terms of the evolution of thrombosis, the incidence of adverse events, and compliance with heparin treatment using 2 types of LMWH available on the market administered in therapeutic doses throughout the period of treatment (Nadroparin) or at therapeutic doses only during the first month of treatment followed by a prophylactic phase at half dose (Parnaparin). A randomized prospective study was carried out on patients under observation with a recent diagnosis of DVT. The objectives of the study were to confirm the effectiveness of therapy with LMWH in terms of prevention of the risk of thromboembolism, of relapse of DVT, and of hemorrhagic complications, and to complete an evaluation of venous recanalization and residual valve competence in the 2 groups of patients. From December 2002 to June 2005, we randomized a total of 91 patients (51 in the Parnaparin group and 40 in the Nadroparin group). Overall, there was 1 case of nonfatal pulmonary embolism (1.1%) at 7 days into therapy with LMWH. There were 3 cases (3.3%) of progression of thrombosis despite therapy with LMWH, 2 cases (5%) in the Nadroparin group, and 1 case (2%) in the Parnaparin group (P = NS), and after suspension of the therapy, there was 1 case of relapse of thrombosis. Three of the 4 thrombotic events occurred in patients with active neoplasia. Moreover, only 1 major hemorrhagic event (1.1%) required blood transfusion. The Doppler ultrasound in the follow-up showed a complete resolution of 56% of the vein thromboses at an average of 6.1 ± 4.6 (mean ± SD) months. Valve competence recovered in 65.9% of cases with no significant difference between the 2 heparin groups. Home treatment of sural and femoral-popliteal DVT using LMWH represents a safe and effective method in the prevention of pulmonary embolism and encourages the process of recanalization of the thrombosed vessel, especially in cases of sural and/or popliteal DVT. Administration can be carried out with the same degree of safety at the therapeutic dose throughout the period of treatment or can be halved after the first month of treatment. In patients with active neoplasia, treatment with oral anticoagulant therapy must be considered.

Recurrent venous thromboembolism: what is the risk and how to prevent it

Venous thromboembolism (VTE) that includes deep vein thrombosis and/or pulmonary embolism is a frequent, severe, and potentially lethal disease. After a first episode, VTE has a strong tendency to recur. While VTE is an acute disease, it may have variable outcomes in early and late phases after initial presentation. Furthermore, the incidence of late, clinically important consequences (postthrombotic syndrome and/or chronic thromboembolic pulmonary hypertension) increases in case of recurrent events. The aims of the present review are (i) to analyze the incidence and risk factors for recurrence of VTE (either those related to the type of first thrombotic event or to the patients), the risks associated with occurrence of recurrent events, and the problems linked to the diagnosis, not always easy, of recurrent events; (ii) to discuss whether or not it is possible to predict the individual risk of recurrence after a first event, by stratifying patients at high or low risk of recurrence, and how this can influence their treatment; (iii) to comment what the current guidelines and guidance suggest/recommend about anticoagulant treatment after a first VTE event and, finally, to propose practical indications on how to manage individual patients affected by VTE.

Prognostic impact of calf muscle near-infrared spectroscopy in patients with a first episode of deep vein thrombosis

BACKGROUND

The risk factors that affect the development of post-thrombotic syndrome (PTS) are not fully recognized, and it is difficult to reliably predict which patients are likely to develop PTS in acute phase of deep vein thrombosis (DVT).

AIMS

To investigate changes in calf muscle deoxygenated hemoglobin (HHb) levels after DVT, and to determine the indicative parameters reflecting the progression of PTS.

METHODS

Seventy-six consecutive patients with a first episode of unilateral DVT were prospectively enrolled. Clinical manifestations were categorized according to the CEAP (Clinical, Etiologic, Anatomical, and Pathophysiologic) classification, and the patients were divided into no-PTS (C(0-3)E(s),A(s,d,p),P(r,o)) and PTS (C(4-6)E(s),A(s,d,p),P(r,o)) groups. Near-infrared spectroscopy (NIRS) was used to measure calf muscle HHb levels at 6 months after diagnosis of DVT. The calf venous blood filling index (HHbFI) was calculated on standing, and the venous ejection index and the venous retention index (HHbRI) were then obtained after exercise. All patients were followed up for more than 24 months after the diagnosis of DVT.

RESULTS

Of 76 patients evaluated, 20 (26.3%) had PTS. The NIRS-derived HHbFI and HHbRI were significantly increased in patients who developed PTS in comparison with those who did not (P = 0.04 and P = 0.0001, respectively). HHbRI was significantly increased in patients with iliofemoral DVT in comparison with patients with calf DVT (P = 0.041). An optimal cut-off point of 2.9 for HHbRI showed the strongest ability to predict the development of PTS, with a sensitivity of 100% and a specificity of 82.1%.

CONCLUSIONS

HHbRI as measured by NIRS is significantly increased in patients with iliofemoral DVT as compared with those with calf DVT. Furthermore, HHbRI > 2.9 is a strong predictor of the development of PTS at 6 months.

Inflammation in deep vein thrombosis and the development of post-thrombotic syndrome: a prospective study

BACKGROUND

The aim of this study was to investigate whether inflammatory markers (interleukin-6 [IL-6] and C-reactive protein [CRP]) in the acute phase of deep vein thrombosis (DVT) are associated with elevated venous outflow resistance (VOR), thrombosis score (TS), reflux and the development of clinical post-thrombotic syndrome (PTS).

METHODS

In 110 patients with a first DVT, plasma concentrations of IL-6 and CRP were determined on the day of admission. VOR, TS and reflux were measured 7 days, 1 and 3 months after diagnosis. After 1 year patients were evaluated for PTS using the Clinical, Etiologic, Anatomic and Pathophysiologic (CEAP) classification and Villalta scale.

RESULTS

Median levels of IL-6 and CRP were 7 pg mL(-1) and 21 mg L(-1), respectively. After 3 months, VOR was elevated in 33 patients (30%), TS in 33 (30%) and reflux in 57 (52%). Incidence of PTS was 36.7% using CEAP>or=3 and 35.4% using Villalta-scale>or=5. Elevated levels of IL-6 and CRP were related to higher outcomes of VOR after 3 months [relative risks (RR) 2.4 (95% CI 1.5-3.9) and 1.4 (1.1-3.3), respectively] and for IL-6 to TS [1.5 (1.1-2.1)]. For reflux no relation was found. After 90 days, elevated outcomes of VOR, TS and reflux were related to PTS after 1 year. The association of IL-6 and CRP with PTS was weak using the CEAP classification with a RR of 1.2 (0.7-2.2) and 1.8 (0.9-3.3) and absent according to the Villalta scale 0.6 (0.2-1.4) and 1.2 (0.6-2.5), respectively.

CONCLUSION

The results of this study suggest that inflammation might play a role in incomplete thrombus clearance, venous outflow obstruction and the development of PTS after 1 year.

Multilayer compression bandaging in the acute phase of deep-vein thrombosis has no effect on the development of the post-thrombotic syndrome

OBJECTIVE

The purpose of this randomized study was to evaluate the influence of immediate multilayer compression bandages before application of elastic stockings in the acute phase of deep-vein thrombosis (DVT) on development of the post-thrombotic syndrome (PTS).

METHODS

Sixty-nine patients with acute symptomatic DVT were randomized to immediate bandaging (n = 34) or no bandaging (n = 35). After reduction of edema sized-to-fit elastic stockings were applied in all patients after 7-14 days. Follow-up visits and non-invasive examinations were planned after 7, 30 and 90 days and 1 year. Venous outflow resistance (VOR) was measured by strain gauge plethysmography. Thrombosis score (TS) and reflux were measured by duplex scanning. After one year patients were evaluated for clinical PTS using both the clinical scale of the CEAP classification and the Villalta score.

RESULTS

Improvement of clinical symptoms and decrease of leg circumference was better on day 7 in the bandaging group, but after 1 and 3 months clinical symptoms had improved equally in both groups. In 7 patients in the no-bandaging group a bandage was applied after all because of persistent edema after 10 days. There were no differences in VOR, TS and reflux. Using the CEAP classification the incidence of PTS was 39% in patients with bandages and 42% in patients without bandages (RR 0.91, 95% CI 0.50-1.66). Using the Villalta score the incidence of PTS was resp. 29 and 33% (RR 0.87, 95% CI 0.41-1.8). There was no difference in severity of PTS.

CONCLUSION

Immediate multilayer compression bandaging in the acute phase of DVT is effective in reducing edema and complaints in the first week, but has no effect on thrombus regression, valve incompetence and the development of clinical PTS after 1 year.

Chronic-Stage Deep Vein Thrombosis of the Lower Extremities

OBJECTIVE

To describe the computed tomographic (CT) findings of chronic deep vein thrombosis (DVT) and its evolution from acute DVT.

METHODS

Fifty-one consecutive patients with 52 legs confirmed as acute DVT by CT venography underwent follow-up computed tomography more than 2 months later. Follow-up CT findings were assessed retrospectively by consensus between 2 radiologists. The frequencies of CT findings were analyzed for affected venous segments: common iliac, external iliac, femoral, popliteal, and calf veins.

RESULTS

Twelve legs (23%) were completely normalized on follow-up computed tomography, but 40 legs (77%) showed abnormal findings as follows: luminal obliteration (n = 16), decreased caliber (n = 30), residual thrombi (n = 3), fibrotic bands (n = 28), ipsilateral muscle enlargement (n = 28), ipsilateral subcutaneous edema (n = 11), and superficial collateral vein development (n = 23). The external iliac vein (26/40, 65%) was the most commonly affected site followed in decreasing order by femoral (29/50, 58%), common iliac (9/18, 50%), popliteal (22/47, 47%), and calf veins (9/43, 21%). Trends were observed whereby luminal obliteration affected iliac veins and fibrotic bands affected femoropopliteal veins.

CONCLUSIONS

Luminal obliteration, decreased caliber, fibrotic bands, ipsilateral muscle enlargement, and superficial collateral vein development are common CT findings in chronic DVT of the lower extremity.

Successful iliac vein and inferior vena cava stenting ameliorates venous claudication and improves venous outflow, calf muscle pump function, and clinical status in post-thrombotic syndrome

OBJECTIVES

Stent therapy has been proposed as an effective treatment of chronic iliofemoral (I-F) and inferior vena cava (IVC) thrombosis. The purpose of this study was to determine the effects of technically successful stenting in consecutive patients with advanced CVD (CEAP3-6 +/- venous claudication) for chronic obliteration of the I-F (+/-IVC) trunks, on the venous hemodynamics of the limb, the walking capacity, and the clinical status of CVD. These patients had previously failed to improve with conservative treatment entailing compression and/or wound care for at least 12 months.

METHODS

The presence of venous claudication was assessed by > or =3 independent examiners. The CEAP clinical classification was used to determine the severity of CVD. Outflow obstruction [Outflow Fraction at 1- and 4-second (OF1 and OF4) in %], venous reflux [Venous Filling Index (VFI) in mL/100 mL/s], calf muscle pump function [Ejection Fraction (EF) in %] and hypertension [Residual Venous Fraction (RVF) in %], were examined before and after successful venous stenting in 16 patients (23 limbs), 6 females, 10 males, median age 42 years; range, 31-77 yearas, left/right limbs 14/9, using strain gauge plethysmography; 7/16 of these had thrombosis extending to the IVC. Contralateral limbs to those stented without prior I-F +/- IVC thrombosis, nor infrainguinal clots on duplex, were used as control limbs (n = 9). Excluded were patients with stent occlusion or stenoses, peripheral arterial disease (ABI <1.0), symptomatic cardiac disease, unrelated causes of walking impairment, and malignancy. Preinterventional data (< or =30 days) were compared with those after endovascular therapy (8.4 months; interquartile range [IQR], 3-11.8 months). Nonparametric analysis was applied.

RESULTS

Compared with the control group, limbs with I-F +/- IVC thrombosis before stenting had reduced venous outflow (OF4) and calf muscle pump function (EF), worse CEAP clinical class, and increased RVF (all, P < 0.05). At 8.4 months (IQR, 3-11.8 months) after successful I-F (+/-IVC) stenting, venous outflow (OF1, OF4) and calf muscle pump function (EF) had both improved (P < 0.001) and the RVF had decreased (P < 0.001), at the expense of venous reflux, which had increased further (increase of median VFI by 24%; P = 0.002); the CEAP status had also improved (P < 0.05) from a median class C3 (range, C3-C6; IQR, C3-C5) [distribution, C6: 6; C4: 4; C3: 13] before intervention to C2 (range, C2-C6; IQR, C2-C4.5) [distribution, C6: 1; C5: 5; C4: 4; C2: 13] after intervention. At this follow up (8.4 months median), venous outflow (OF1, OF4), calf muscle pump function (EF), and RVF of the stented limbs did not differ significantly from those of the control; significantly worse (P < 0.025) were the amount of venous reflux (VFI), and the CEAP clinical class, despite the improvement with stenting. Incapacitating venous claudication noted in 62.5% (10 of 16, 95% CI, 35.8%-89.1%) of patients (15 of 23 limbs; 65.2%, 95% CI, 44.2%-86.3%) before stenting was eliminated in all after stenting (P < 0.001).

CONCLUSIONS

Successful I-F (+/-IVC) stenting in limbs with venous outflow obstruction and complicated CVD (C3-C6) ameliorates venous claudication, normalizes outflow, and enhances calf muscle pump function, compounded by a significant clinical improvement of CVD. The significant increase in the amount of venous reflux of the stented limbs indicates that elastic or inelastic compression support of the successfully stented limbs would be pivotal in preventing disease progression.

Late results of catheter-directed recombinant tissue plasminogen activator fibrinolytic therapy of iliofemoral deep venous thrombosis

PURPOSE

To evaluate the efficacy of catheter-directed low-dose recombinant tissue-type plasminogen activator infusion in the treatment of iliofemoral deep venous thrombosis and prevention of post-thrombotic syndrome.

METHOD

Eighteen patients (out of 260 evaluated) with acute iliofemoral deep venous thrombosis and no previous evidence of venous insufficiency were prospectively selected for thrombolytic therapy. Catheter-directed low-dose recombinant tissue-type plasminogen activator (1 mg/h) was infused into the thrombotic segments.

RESULTS

Effective fibrinolysis was achieved in 14 of 18 cases, with correlation between effective fibrinolysis and major/complete resolution of acute signs and symptoms (P <.01). There were no episodes of major complications. Four patients presented with early rethrombosis (1 to 8 weeks). Individuals were followed for a period up to 131 weeks (average, 85.2). The incidence of clinical signs and symptoms of venous insufficiency and duplex-scan findings of valvular reflux was significantly lower in the patients in which lytic therapy succeeded and patency was kept, compared with patients experiencing acute therapeutic failure or rethrombosis (P <.01).

CONCLUSIONS

Low-dose recombinant tissue-type plasminogen activator fibrinolytic therapy is safe and effective in the treatment of acute iliofemoral venous thrombosis. The late evolution as revealed clinically and by ultrasound was superior in patients for whom lytic therapy was effective.

THE CONUNDRUM OF CLAUDICATION

Stable claudication has traditionally been treated conservatively by many clinicians as operative therapies involve considerable risk for a condition that is often slowly progressive and non-fatal. The relative safety of less invasive endovascular techniques brings potential survival benefits from the increased exercise tolerance that result. We aimed to revisit and clarify the aetiologies of intermittent claudication in a review of the rarer causes that can mimic atherosclerotic occlusive disease. An extensive search of Medline, Embase and the Cochrane databases was carried out to compile published work addressing the aetiology of claudication and specific non-atherosclerotic causes. The reference lists of these manuscripts were also searched for relevant articles. There are several vasculogenic and neurogenic causes for intermittent claudication, many of which are unrelated to atherosclerosis. Recognition of these rarer syndromes is essential when planning endovascular or operative management strategies. Consideration of non-atherosclerotic differential diagnoses is recommended when assessing the patient with intermittent claudication. This is particularly critical in the young patient whose pattern of symptoms and risk factors may not fit precisely with atherosclerosis.

Current approaches and controversial issues in the diagnosis of deep vein thrombosis via duplex Doppler ultrasound

Duplex and color Doppler sonography (DUS) is currently the technique of choice for the diagnosis of deep venous thrombosis (DVT) in symptomatic patients, because it has proven safe and cost-effective, with a very high sensitivity and specificity (96% and 98%, respectively) for the diagnosis of proximal DVT. Several issues regarding its method and clinical indications remain controversial, however. Although isolated calf vein thrombosis does not seem to have a significant adverse outcome in the short term, scanning the calf only in patients with localized symptoms or signs is cost-effective. Bilateral examination is indicated in high-risk patients or when screening asymptomatic patients. When negative, a complete DUS examination of the proximal and distal veins, at least down to the level of the popliteal trifurcation, allows withholding anticoagulant therapy without the risk of major complications. This examination may be repeated if signs or symptoms worsen. Some populations of asymptomatic patients at high risk of DVT may benefit from DUS screening. Bilateral DUS examination of lower limb veins should be performed as the initial examination in the workflow of pulmonary embolism only in patients with risk factors for DVT. Recurrent thrombosis is a challenging diagnosis for all imaging modalities. A diagnostic strategy combining clinical probability score and D-dimer test may refine the selection of patients. The pitfalls and limitations of venous DUS are related to vein anatomy, flow changes, technical issues, and operator expertise.

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.

The utility of quantitative calf muscle near-infrared spectroscopy in the follow-up of acute deep vein thrombosis

BACKGROUND

To investigate patterns of venous insufficiency and changes in calf muscle deoxygenated hemoglobin (HHb) levels after an acute deep vein thrombosis (DVT).

METHODS

A total of 78 limbs with an acute DVT involving 156 anatomic segments were evaluated with duplex scanning and near-infrared spectroscopy (NIRS) at 1, 3, 6 and 12 months. Venous segments were examined whether they were occluded, partially recanalized, and totally recanalized, and the development of venous reflux was noted. The NIRS was used to measure calf muscle HHb levels. Calf venous blood filling index (HHbFI) was calculated on standing, then the calf venous ejection index (HHbEI), and the venous retention index (HHbRI) were obtained after exercise.

RESULTS

The segments investigated were the common femoral vein (CFV; 38 segments), femoral vein (FV; 37), popliteal vein (POPV; 44), and calf veins (CV; 37). At 1 year, thrombi had fully resolved in 67% of the segments, 27% remained partially recanalized, 6% were occluded. The venous occlusion was predominant in the FV (24%) at 1 year. On the contrary, rapid recanalization was obtained in CV than proximal veins at each examination (P < 0.01). Venous reflux was predominant in POPV (55%), followed by FV (19%), and no reflux was found in CV. At 1 year, the HHbFI in POPV reflux patients was significantly higher than those with resolution (0.19 +/- 0.14, 0.11 +/- 0.05 microm s, P = 0.009, respectively). Similarly, there was a significant difference in the HHbRI between the two groups (3.08 +/- 1.91, 1.42 +/- 1.56, P = 0.002, respectively). In patients with FV occlusion, the value of HHbRI was significantly higher than those with complete resolution (2.59 +/- 1.50, 1.42 +/- 1.56, P = 0.011, respectively).

CONCLUSIONS

The lower extremity venous segments show different proportions of occlusion, partial recanalization, and total recanalization. The CV shows more rapid recanalization than proximal veins. The NIRS-derived HHbFI and HHbRI could be promising parameters as the overall venous function in the follow-up of acute DVT. These findings might be very helpful for physician in detecting patients who require much longer follow-up studies.

Cost effectiveness of bemiparin sodium versus unfractionated heparin and oral anticoagulants in the acute and long-term treatment of deep vein thrombosis

INTRODUCTION

Low-molecular-weight heparins (LMWHs) are at least as effective and well tolerated as unfractionated heparin (UFH) in the treatment of deep vein thrombosis (DVT), offering easier administration and obviating the need for anticoagulant monitoring, but have a higher acquisition cost than UFH.

OBJECTIVE

To quantify the potential economic impact of two regimens of subcutaneous bemiparin 115 IU/kg/day for 7-10 days (plus oral anticoagulants [OAC] or followed by long-term bemiparin 3500IU) versus dose-adjusted intravenous UFH for 7 days plus OAC for 3 months in the acute and long-term treatment of DVT. The representative patient was a 62-year-old, 77 kg male with proximal DVT of the lower limbs.

METHODS

A cost-effectiveness analysis was performed using a decision-tree modelling approach. The results were expressed in terms of costs (euro, 2002 values) and incremental cost effectiveness. The treatment costs (hospital stay, physician services, drug administration) and costs incurred due to complications (pulmonary embolism, recurrent DVT, bleeding events, thrombocytopenia and deaths) during the 3-month study period were considered for the primary analysis. Life expectancy and QALYs were considered for the secondary analysis. The study was performed in the setting of the Spanish National Health System.

RESULTS

Bemiparin plus OAC or long-term bemiparin for 3 months provided net cost savings of euro 769 and euro 908 per patient, respectively, compared with UFH plus OAC (UFH plus OAC euro 4128 vs bemiparin plus OAC euro 3359 vs long-term bemiparin euro 3220). Bemiparin plus OAC and long-term bemiparin for 3 months were calculated to avoid 27 and 7 additional VTE events, respectively, per 1000 patients treated. Bemiparin plus OAC or long-term bemiparin increased quality-adjusted life expectancy by approximately 1.72 and 0.74 years, respectively, compared with UFH plus OAC. The univariate sensitivity analysis supported the cost effectiveness of bemiparin in all the ranges tested for complications and costs.

CONCLUSIONS

Our model suggests that bemiparin plus OAC or long-term bemiparin for 3 months may be dominant strategies over UFH plus OAC in the treatment of DVT from the Spanish National Health System perspective, offering better outcomes and cost savings. Long-term bemiparin may be a cost-neutral alternative to bemiparin plus OAC.

Patterns of Venous Insufficiency after an Acute Deep Vein Thrombosis

BACKGROUND

The purpose of this study was to investigate patterns of venous insufficiency during a 12-month period after an acute deep vein thrombosis.

STUDY DESIGN

Seventy limbs in 67 patients with an acute deep vein thrombosis (DVT) involving 147 anatomic segments were evaluated with duplex scanning at 1 month, 3 months, 6 months, and 1 year. Venous segments were examined whether they were occluded, partially recanalized, or totally recanalized, and the development of venous reflux was evaluated.

RESULTS

The segments investigated were the common femoral vein (38 segments), femoral vein (33 segments), popliteal vein (36 segments), and calf veins (40 segments). There were 35 limbs with isolated DVT and the remaining 35 had multisegment DVT. At 1 year, thrombi had fully resolved in 76% of the segments, 20% remained partially recanalized, and 5% were occluded. The venous occlusion was most predominant in the femoral vein (21%) at 1 year. On the contrary, rapid recanalization was obtained in calf veins than in proximal veins at each examination (p < 0.01). Deep vein insufficiency was detected as early as 1 month after development of DVT, and the reflux was most predominant in popliteal veins (56%), followed by femoral veins (18%). No reflux was found in calf veins. Multisegment DVTs had a significantly higher incidence of deep vein insufficiency than single segment DVTs at 1 year. Development of superficial venous insufficiency was found in 5 limbs (7%) and perforating vein insufficiency in 5 (7%).

CONCLUSIONS

Lower extremity venous segments showed different proportions of occlusion, partial recanalization, and total recanalization. Calf veins showed more rapid recanalization than proximal veins. Venous reflux was noted as early as 1 month. The limbs involving multisegment DVTs on initial examination had a higher incidence of deep vein insufficiency and could require much longer followup studies.

Generalized changes in venous distensibility in postthrombotic patients

INTRODUCTION

In situ biomechanical properties of peripheral large veins were compared between asymptomatic young patients who had previously unilateral femoro-popliteal deep venous thrombosis (DVT) and age-matched, healthy controls; the aim of this study was to assess local or generalized alterations of venous wall biomechanics in postthrombotic patients.

PATIENTS AND METHODS

Inner diameters of both common femoral veins, right axillary vein, and right internal jugular veins were measured in two directions by ultrasonography. Venous pressure was altered by posture changes (standing and lying) and by application of graded and controlled Valsalva. Ten postthrombotic young patients without any symptoms and 11 age-matched control subjects were included.

RESULTS

In postthrombotic patients, both the affected and unaffected common femoral vein diameters and capacities were larger at low transmural pressures than those for the control group, but they demonstrated significantly less distensibility when higher pressures were applied. Similarly, in the internal jugular vein, capacity without Valsalva was significantly higher in postthrombotic patients and distensibility was reduced (statistically significant in the erect position). Pressure-induced changes in axillary vein diameter were negligible.

CONCLUSIONS

In situ diameter and capacity changes, and in situ distensibility of the femoral veins on both sides (i.e., the side of previous thrombosis as well as the disease-free side) and of the jugular veins are reduced in the young DVT patients compared to veins of the age-matched, healthy controls. The pathophysiological mechanism of generalized venous wall changes in these young DVT patients remains unknown.

Venous claudication in iliofemoral thrombosis: long-term effects on venous hemodynamics, clinical status, and quality of life

OBJECTIVE

We evaluated the long-term impact of iliofemoral thrombosis (I-FDVT) on walking capacity, venous hemodynamic status, CEAP class, venous clinical severity, and quality of life, and determined the prevalence of venous claudication.

MATERIALS AND METHODS

All patients with prior I-FDVT, assessed at our institution since 1990, were called for follow-up. Those with walking impairment due to arterial disease (ABI < 1.0 postexercise) or unrelated causes and those thrombectomized or thrombolyzed were excluded; 39 patients (22-83 years, median 46 years) were included. Median follow-up was 5 years (range 1-23 years). Investigation included classification in CEAP and Venous Clinical Severity Scoring (VCSS) systems, air-plethysmography (outflow fraction [OF], venous filling index [VFI], residual volume fraction [RVF]) and venous duplex, treadmill (3.5 km/h, 10%) to determine initial (ICD) and absolute (ACD) claudication distances, and quality of life assessment (SF-36). Nonaffected limbs of patients with unilateral I-FDVT (37 of 39) comprised the control group. Data are presented as median and interquartile range.

RESULTS

A total of 81% of limbs with I-FDVT had superficial and deep reflux and 19% superficial reflux; reflux in control limbs was 29.7% (P < 0.001) and 27% (P > 0.2), respectively; 43.6% (17 of 39; 95% CI, 27-60%) of patients developed venous claudication ipsilateral to I-FDVT (ICD: 130 m, range 105-268 m), compelling 15.4% (6 of 39; 95% CI, 3.5-27%) to discontinue treadmill (ACD: 241 m, range 137-298 m). Limbs with prior I-FDVT had a lower OF (37%, range 32.2-43%; P < 0.001), abnormally higher VFI (3.8 mL/s, range 2.5-5.7 mL/s; P < 0.001), and RVF (45%, range 32.5-51.5%; P = 0.006), and clinical impairment in CEAP and VCSS systems (P < 0.0001). Patients with I-FDVT had impaired physical functioning (P = 0.02) and role (P = 0.033), general health (P = 0.001), social function (P = 0.047), and mental health (P = 0.043).

CONCLUSIONS

A total of 43.6% of those with prior I-FDVT developed venous claudication compelling interruption of walking in 15.4%. Prior I-FDVT caused outflow impairment and a large residual venous volume and reflux, resulting in marked clinical and quality of life compromise. Standardized challenge enabled discrimination of those with clinically relevant impairment.

Pathogenesis of varicose veins

BACKGROUND

varicose veins are present in up to 40% of the population. They may be associated with considerable morbidity. Around 70% of patients with chronic venous insufficiency have evidence of superficial venous incompetence on duplex imaging.

METHODS

in this publication we review the evidence available regarding the pathogenesis of varicose veins.

RESULTS

a number of theories have been suggested. The present data suggests that abnormalities in the venous endothelium and smooth muscle cells result in vein wall dilatation with secondary valvular incompetence. However, there is also evidence to support acquired venous valve failure. Congenital venous valve abnormalities have not been well studied.

CONCLUSION

further work is required on this relatively neglected topic. The use of improved imaging such as high-resolution ultrasound is likely to significantly improve our understanding of venous valve function and pathology.

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

OBJECTIVES

to evaluate clinical and functional long-term outcomes following pregnancy-related medically treated iliofemoral deep venous thrombosis (DVT).

DESIGN

retrospective follow-up of patients identified through a registry search.

MATERIAL AND METHODS

twenty-five women underwent clinical examination, colour duplex ultrasound and computerised strain-gauge plethysmography on two occasions a mean of nine and 16 years after DVT.

RESULTS

40% of the patients were completely asymptomatic and 52% had no clinical signs of venous disease after a mean follow-up of 16 years. The clinical signs were in general mild, and none of the 25 patients had skin changes or ulcers. Deep venous reflux was found in 36% of the patients; the same percentage at nine- and 16-years follow-up, and 24% had normal ultrasonographic appearance of all deep veins. None of the patients had plethysmographic evidence of outflow obstruction. There was a significant relationship between measures of venous reflux and the presence of leg swelling, but there was no clear relation between functional abnormalities and the extent of the initial DVT.

CONCLUSION

even after 16 years there are relatively mild symptoms and signs of venous disease in women with medically treated pregnancy-related iliofemoral DVT. Our results do not support earlier stated opinions that these patients represent a particular risk group for developing post-thrombotic syndrome.

Evolution of deep venous thrombosis: a 2-year follow-up using duplex ultrasound scan and strain-gauge plethysmography

OBJECTIVE

The development of the post-thrombotic syndrome (PTS) and recurrence of deep venous thrombosis (DVT) are not yet fully understood. The aim of the study was to identify factors that lead to the long-term complications of DVT.

METHODS

In a 2-year prospective follow-up study, duplex scanning and strain-gauge plethysmography were used to evaluate DVT in relation to the development of long-term complications. Each of the 12 segments examined was assigned as a thrombosis score (TS). A total TS was calculated for each leg. Patent segments were assigned a TS = 0, noncompressible vein segments with flow TS = 1 and noncompressible vein segments without flow TS = 2. The degree of resolution of DVT and the incidence, timing, and outcome of further thrombotic events were measured during 24 months of follow-up.

RESULTS

The study involved 86 legs with DVT. The 2-year follow-up was completed for 70 legs. Within 3 months, only 1% of the originally occluded proximal deep vein segments were still occluded. Between all time intervals, from month 12 to month 24, for example, thrombus regression continued in 36% of the legs and thrombus propagation continued in 27%. Multiple regression analysis revealed that an increase in age (P = .008) and proximal location of the original DVT (P = .05) was significantly related to thrombus propagation. Multiple regression analysis showed that the risk factors for clinical signs of PTS were a high venous outflow resistance after 1-month and 12-month follow-ups (P <or= .002) and a high thrombosis score in the proximal veins after 3 months (P = .008).

CONCLUSIONS

In the follow-up of older patients and patients with proximal DVT, evolution was shown to be an unstable process with continuing propagation for 2 years. The risk factors for the development of PTS were a slow decrease in venous outflow resistance or a high thrombosis score of the proximal veins after 3 months.

The patterns and distribution of residual abnormalities between the individual proximal venous segments after an acute deep vein thrombosis

INTRODUCTION

The subsequent course of residual abnormalities after an acute deep vein thrombosis (DVT) can vary within individual venous segments. To investigate the pattern of response within the individual venous segment, we used sequential duplex scanning to determine whether certain segments are more likely to recanalize or remain occluded.

METHODS

The anatomic segments involved in 63 above-knee DVTs were examined with duplex scanning at 1 week, 1 month, 6 months, and 1 year after the acute event. The segments under investigation were the external iliac vein (EIV), common femoral vein (CFV), superficial femoral vein (SFV), and popliteal vein (PV). Reflux studies were performed at each follow-up examination. During the follow-up period the segments were examined to see whether they were occluded, partially recanalized, or totally recanalized and the development of reflux was noted.

RESULTS

Most DVTs were multisegmental with a total number of 171 sites involved. Initially, a greater number of segments were occluded (71%) than partially thrombosed (29%). The occluded segments were predominantly in the SFV and PV. At 1 year the thrombi had fully resolved in 60% of the venous segments, 27% remained partially recanalized, and 13% were occluded. The venous segments that resolved within the first 6 months had a higher rate of valvular competence than those that resolved from 6 months to 1 year. The SFV and PV had a higher incidence of valvular incompetence than the EIV and CFV. All venous segments that were partially recanalized at 1 year were found to have significant reflux. The SFV had the highest incidence of total occlusion at the end of 1 year (36%). Many of the occluded SFVs had established collateral pathways that displayed no evidence of reflux.

CONCLUSION

The lower extremity venous segments differ in respect to their tendencies to partially or fully recanalize or remain occluded. All partially recanalized segments displayed reflux. Fully resolved segments that recanalized within the first 6 months were more likely to have competent valves than those that recanalized after 6 months. In the presence of an occluded SFV, collateral pathways establish rapidly. No reflux was found in these collaterals.

Low molecular weight heparin versus oral anticoagulants in the long-term treatment of deep venous thrombosis

PURPOSE

The purpose of this study was to evaluate whether low molecular weight heparin (LMWH) could be equal or more effective than conventional oral anticoagulants (OAs) in the long-term treatment of deep venous thrombosis (DVT).

METHODS

One hundred fifty-eight patients with symptomatic DVT of the lower limbs confirmed by means of duplex ultrasound scan were randomized to receive 3 to 6 months' treatment with nadroparine calcium or acenocoumarol. Quantitative and qualitative duplex scan scoring systems were used to study the evolution of thrombosis in both groups at 1, 3, 6, and 12 months.

RESULTS

During the 12-month surveillance period, two (2.5%) of the 81 patients who received LMWH and seven (9%) of the 77 patients who received OAs had recurrence of venous thrombosis (not significant). In the LMWH group no cases of major bleeding were found, and four cases (5.2%) occurred in the OA group (not significant). The mortality rate was nine (11.1%) in the LMWH group and 7.8% in the OA group (not significant). The quantitative mean duplex scan score decreased in both groups during the follow-up and had statistical significance after long-term LMWH treatment on iliofemoral DVT (1, 3, 6, and 12 months), femoropopliteal DVT (1-3 months), and infrapopliteal DVT (first month). Duplex scan evaluation showed that the rate of venous recanalization significantly increased in the common femoral vein at 6 and at 12 months and during each point of follow-up in the superficial and popliteal veins in the LMWH group. Reflux was significantly less frequent in communicating veins after LMWH treatment (17.9% vs 32.2% in the OA group). The reflux rates in the superficial (22.4% in the LMWH group, 30.6% in OA group) and deep (13.4% vs 17.7%) venous system showed no significant differences between groups.

CONCLUSIONS

The unmonitored subcutaneous administration of nadroparine in fixed daily doses was more effective than oral acenocoumarol with laboratory control adjustment in achieving recanalization of leg thrombi. With nadroparine, there was less late valvular communicating vein insufficiency, and it was at least as efficacious and safe as oral anticoagulants after long-term administration. These results suggest that LMWHs may therefore represent a real therapeutic advance in the long-term management of DVT.

The postthrombotic syndrome in relation to venous hemodynamics, as measured by means of duplex scanning and strain-gauge plethysmography

PURPOSE

Venous hemodynamics were evaluated in relation to the postthrombotic syndrome (PTS) 7 to 13 years after deep venous thrombosis (DVT).

METHODS

The presence of flow, reflux, and compressibility of 1394 vein segments in 82 patients was assessed by means of duplex scanning. The venous outflow resistance was measured by means of strain-gauge plethysmography. The venous hemodynamics were related to the clinical severity of the PTS, characterized by the CEAP (clinical, etiologic, anatomic, pathophysiologic) classification.

RESULTS

In patients with severe clinical symptoms of PTS, the prevalence of reflux was significantly higher. There was no relationship between the severity of the PTS and the noncompressibility or the combination of reflux and noncompressibility or an increased venous resistance. By means of multiple regression analysis with the variables of age, gender, reflux, and venous resistance, age and reflux were shown to be the main contributors to the severity of PTS. Significantly more patients (64%) with severe signs of PTS had a combination of deep and superficial reflux. In each of the traceable vein segments, the mean of the CEAP classification was calculated for the vein segments with and without reflux. In the proximal superficial femoral vein (P <.001), distal superficial femoral vein (P <.05), and popliteal vein (P <.05), a significantly higher mean CEAP classification was found in the veins with reflux, whereas in the distal, long, and short saphenous veins, no such relationship was found.

CONCLUSION

Most patients with severe PTS had a combination of deep and superficial reflux. Reflux in the deep proximal veins contributes significantly to the PTS.