Summaries of recent phlebological abstracts

Int Angiol 2020. Epub ahead of print, doi: 10.23736/S0392-9590.20.04273-X.

The authors’ aims were to quantitatively evaluate edema of the lower legs in patients with saphenous varicose veins and to determine the association between leg edema and venous hemodynamics of the lower legs. In this retrospective study, 140 patients with saphenous veins over a one-year period were included. Body composition values, including mass index (BMI), extracellular water/total body water (ECW/TBW) of each leg, and skeletal muscle mass of each leg, were measured by segmental multifrequency bioelectrical impedance analyzer. Venous hemodynamics of the leg, including functional venous volume, venous filling index (VFI), and ejection fraction, was assessed using air plethysmography. Saphenous and deep vein refluxes were evaluated by duplex scan. Fifty-eight men and 82 women with a mean age of 66.0 years were analyzed. On visual inspection, 204 legs had saphenous-type varicose veins, while 76 legs did not. The legs were divided into two groups according to the presence or absence of leg edema, which was defined as extracellular water (ECW) divided by total body water (TBW) ECW/TBW ≥ 0.390 and <0.390, respectively. One-hundred seventy-eight legs had leg edema. In univariate analysis, there were significant differences in age, sex, the presence of saphenous varicose veins, hypertension, and VFI between legs with edema and those without edema. Multivariable logistic regression analysis for leg edema detected age, female gender, and VFI as an independent risk factor for leg edema.

The authors concluded that older age, female gender, and increased venous filling index were identified as independent risk factors for leg edema.

Int J Hyperthermia 2020; 37: 231–244.

The authors studied the efficacy, safety, and temperature rise in a sheep model using high-intensity focused ultrasound (HIFU). In vivo experiments were conducted on two saphenous veins to measure the temperature rise induced at the vein wall during HIFU ablation, and were compared with reported RFA-induced thermal rise. Thermocouples were inserted in situ to perform 20 measurements during 8-s ultrasound pulses at 3 MHz. Eighteen saphenous veins of nine anesthetized sheep (2–2.5% Isoflurane) were then exposed to similar pulses (85 W acoustic, 8 s). Animals were followed up at 30, 60, and 90 days posttreatment (n = 3 animals per group). At the end of the follow-up, vein segments and perivenous tissues were harvested and histologically examined. Temperatures induced by HIFU pulses were found to be comparable to reported RFA treatments. Likewise, histological findings were like the ones reported after RFA and laser-based coagulation necrosis of the vein wall, thrombotic occlusions, and vein wall fibrosis.

The authors concluded that the results in the animal model support the effectiveness and safety of HIFU for non-invasive venous ablation.

J Vasc Surg Venous Lymphat Disord 2019; 7: 387–391.

The authors’ aim was to investigate the impact of endovenous ablation of the great saphenous vein (GSV) on the degree of tumescence of the glans penis during penile erection as well as on global erectile function (EF). Sixty-two patients were scheduled for one of three different methods of endoluminal treatment. The questionnaire the patients were given was composed of the EF domain of the International Index of Erectile Function, an additional question that has been validated for assessment of swelling (tumescence) of the glans penis, and a question on the use of erectogenic medication. Seven out of 62 patients (11%) reported a postoperative enlargement of the glans penis on penile erection compared with the subjectively assessed glans tumescence before surgery. Three patients (5%) reported an increased tumescence of the glans one week after surgery, and four (7.4%) different patients reported the effect three months after surgery. Of these seven men, three had normal EF (score ≥26) at any time. One patient had mild erectile dysfunction before the operation, with an improvement to normal EF from week 1 throughout the observation in the study (three months).

The authors concluded that this is the first prospective study that confirms an unexpected side effect of endoluminal treatment of the GSV occurring in approximately 10% of men.

J Thromb Thrombolysis 2019; 48: 603–609.

The authors investigated whether unfavorable fibrin clot properties can predict post-thrombotic venous ulcers. In 186 consecutive patients with a previous diagnosis of deep vein thrombosis (DVT) at three months after the indexed event, the following were determined: plasma fibrin clot characteristics, including clot permeability and lysability, inflammatory markers, thrombin generation, and fibrinolysis proteins. Occurrence of post-thrombotic syndrome (PTS) and venous ulcers were recorded during a median follow-up of 53 months. Fifty-seven DVT patients (30.6%) developed PTS, including 12 subjects (6.45%) with a venous ulcer (4 individuals with recurrent ulcers). Patients who developed ulcers compared with the remainder had at enrolment 13.0% lower clot permeability (K_s), 17.4% longer clot lysis time (CLT), 13.1% longer lag phase of clot formation, and 5.0% higher maximum absorbance, with no difference in fibrinogen, C-reactive protein, and thrombin generation. The baseline prothrombotic fibrin clot phenotype (K_s ≤ 6.5 × 10⁻⁹ cm² and CLT > 100 min) was associated with a higher risk of ulcers [hazard ratio (HR), 5.37; 95% confidence interval (CI), 1.3–21.5]. A multivariate model adjusted for age, sex, and fibrinogen showed that independent predictors of the ulcer occurrence were body mass index (HR 1.53; 95% CI 1.30–1.86), CLT (HR 1.43; 95% CI 1.04–2.05), and α₂-antiplasmin (HR 0.95; 95% CI 0.90–0.99).

The authors concluded that this study suggested that formation of denser fibrin clots with impaired fibrinolysis predisposes to post-thrombotic venous ulcers.

J Thromb Haemost 2020. Epub ahead of print, doi: 10.1111/jth.14817.

The authors studied the outcomes of consecutive patients with severe COVID-19 in Tongji hospital in a retrospective analysis. Morbidity from disseminated intravascular coagulation and venous thromboembolism is a risk in this patient population. Four-hundred forty-nine patients with severe COVID-19 were enrolled, and 99 patients received low-molecular weight heparin (LMWH) for seven days or longer. The 28-day mortality of patients treated with heparin who had sepsis-induced coagulopathy (SIC) scores > 4 (40% vs. 64.2%) and D-dimer >6-fold of normal (32.8% vs. 52.4%) was lower than those not treated with heparin.

The authors concluded that anticoagulant therapy with LMWH or heparin is associated with a better prognosis in severe COVID-19 patients meeting the SIC criteria or with markedly elevated D-dimer.

Ann Vasc Surg 2020. Epub ahead of print, doi: 10.1016/j.avsg.2020.02.010.

The authors performed a retrospective review of a prospectively maintained database of all patients undergoing endovenous stenting with a covered stent for chronic occlusive iliocaval disease over a three-year period. Twenty covered self-expanding stents were placed and 13 balloon expandable covered stents were placed in 10 patients. The inferior vena cava, common iliac, and external iliac veins were treated. Median follow-up was 12.1 months. Ninety percent of the patients maintained patency of their stents. All symptomatic patients had improvement in pain, venous ulceration, and venous claudication. Lower extremity edema improved in 89% of the patients.

The authors concluded that covered stents placed in patients with chronic venous occlusions are performed safely, and long term outcomes are promising. They did ascertain that further studies must be done to better understand efficacy and cost.

Thromb Res 2020. Epub ahead of print, doi: 10.1016/j.thromres.2020.04.013.

The authors studied the incidence of the outcome of symptomatic acute pulmonary embolism (PE), deep vein thrombosis (DVT), myocardial infarction, or systemic arterial embolism in 184 patients in the intensive care units of three Dutch hospitals. All patients received thromboprophylaxis. They found that venous thromboembolism occurred in 27%. The most frequent thrombotic complication was PE. Age and coagulopathy were independent predictors of thrombotic complications. Arterial thrombotic complications occurred in 3.7% of the patients. Infection with COVID-19 is thought to increase the risk of venous and arterial thromboembolism secondary to inflammation, hypoxia, immobilization, and diffuse intravascular coagulation.

The authors recommend aggressive prophylaxis in the severely ill ICU patients infected with COVID-19.

J Vasc Int Radiol 2020; 31: 635–643.

The authors in this study retrospectively analyzed data from 130 patients who underwent catheter-directed thrombolysis and stent placement for iliac vein compression syndrome (IVCS). Factors affecting the development of recurrent deep venous thrombosis in the ipsilateral and contralateral leg were identified. Ipsilateral DVT occurred in 5.4% and contralateral DVT occurred in 8.5% of patients. Using multivariate analysis, thrombophilia, presence of inferior vena cave filter, and in stent thrombosis were predictors of ipsilateral DVT early during follow-up. Contralateral DVT was associated with stent location (extension into the inferior vena cava) and in stent thrombosis occurring late in follow-up.