Fake-news-free evidence-based communication for proper vein-lymphatic disease management

Published scientific evidence demonstrate the current spread of healthcare misinformation in the most popular social networks and unofficial communication channels. Up to 40% of the medical websites were identified reporting inappropriate information, moreover being shared more than 450,000 times in a 5-year-time frame. The phenomenon is particularly spread in infective diseases medicine, oncology and cardiovascular medicine. The present document is the result of a scientific and educational endeavor by a worldwide group of top experts who selected and analyzed the major issues and related evidence-based facts on vein and lymphatic management. A section of this work is entirely dedicated to the patients and therefore written in layman terms, with the aim of improving public vein-lymphatic awareness. The part dedicated to the medical professionals includes a revision of the current literature, summing up the statements that are fully evidence-based in venous and lymphatic disease management, and suggesting future lines of research to fulfill the still unmet needs. The document has been written following an intense digital interaction among dedicated working groups, leading to an institutional project presentation during the Universal Expo in Dubai, in the occasion of the v-WINter 2022 meeting.

Sclerotherapy of lower limb veins: Indications, contraindications and treatment strategies to prevent complications - A consensus document of the International Union of Phlebology-2023

BACKGROUND

Sclerotherapy is a non-invasive procedure commonly used to treat superficial venous disease, vascular malformations and other ectatic vascular lesions. While extremely rare, sclerotherapy may be complicated by serious adverse events.

OBJECTIVES

To categorise contraindications to sclerotherapy based on the available scientific evidence.

METHODS

An international, multi-disciplinary panel of phlebologists reviewed the available scientific evidence and developed consensus where evidence was lacking or limited.

RESULTS

Absolute Contraindications to sclerotherapy where the risk of harm would outweigh any benefits include known hypersensitivity to sclerosing agents; acute venous thromboembolism (VTE); severe neurological or cardiac adverse events complicating a previous sclerotherapy treatment; severe acute systemic illness or infection; and critical limb ischaemia. Relative Contraindications to sclerotherapy where the potential benefits of the proposed treatment would outweigh the risk of harm or the risks may be mitigated by other measures include pregnancy, postpartum and breastfeeding; hypercoagulable states with risk of VTE; risk of neurological adverse events; risk of cardiac adverse events and poorly controlled chronic systemic illness. Conditions and circumstances where Warnings and Precautions should be considered before proceeding with sclerotherapy include risk of cutaneous necrosis or cosmetic complications such as pigmentation and telangiectatic matting; intake of medications such as the oral contraceptive and other exogenous oestrogens, disulfiram and minocycline; and psychosocial factors and psychiatric comorbidities that may increase the risk of adverse events or compromise optimal treatment outcomes.

CONCLUSIONS

Sclerotherapy can achieve safe clinical outcomes provided that (1) patient-related risk factors and in particular all material risks are (1a) adequately identified and the risk benefit ratio is clearly and openly discussed with treatment candidates within a reasonable timeframe prior to the actual procedure; (1b) when an individual is not a suitable candidate for the proposed intervention, conservative treatment options including the option of 'no intervention as a treatment option' are discussed; (1c) complex cases are referred for treatment in controlled and standardised settings and by practitioners with more expertise in the field; (1d) only suitable individuals with no absolute contraindications or those with relative contraindications where the benefits outweigh the risks are offered intervention; (1e) if proceeding with intervention, appropriate prophylactic measures and other risk-mitigating strategies are adopted and appropriate follow-up is organised; and (2) procedure-related risk factors are minimised by ensuring the treating physicians (2a) have adequate training in general phlebology with additional training in duplex ultrasound, procedural phlebology and in particular sclerotherapy; (2b) maintain their knowledge and competency over time and (2c) review and optimise their treatment strategies and techniques on a regular basis to keep up with the ongoing progress in medical technology and contemporary scientific evidence.

Using the Caprini Risk Score to Increase Awareness of Venous Thrombus Embolism in the Community: Know Your Score II

To assess individual participants' baseline thrombosis risk calculated by Caprini Risk Score (CRS) before injury, illness, or hospitalization occur, to increase the awareness of venous thromboembolism (VTE) by viewing 2 short videos. A cross-sectional study was conducted online between August 2022 and January 2023 in the USA, UK, and India to assess the risk of thrombosis of individuals as a baseline. One nursing practitioner and 4 high school students were on the research team. Descriptive statistical methods were used in data analysis. A total of 928 usable completed questionnaires from 945 participants were analyzed. The mean CRS was 4.93 ± 3.175; 0 to 4 (N  =  460, 49.6%), 5 to 8 (N  =  394, 42.5%), and 9 (N  =  74: 8.0%). History of blood clots (N  =  247, 26.6%), <40 years old (N  =  133, 52.6%); women on oral contraceptives (N  =  324, 34.9%), history of smoking (30%), diabetes (26%), and inflammatory bowel disease (IBD; 17.3%). Top-level findings: High incidence of family history of thrombosis (26.6%), smoking, diabetes, contraceptives, and IBD. The average CRS (7.9) in patients over 75 years indicates that even a minor surgical procedure may be associated with significant VTE risk. We achieved an important goal by increasing awareness of VTE using this unique method involving high school students and a nurse working with friends and families to complete the CRS assessment. Encouraging the respondents to share information with their personal physicians prior to the event and keep these data in their medical file is a potential valuable source of saving time. This study emphasizes the importance of individuals collecting baseline information prior to illness or hospitalization.

Prognostic Value of Venous Thromboembolism Risk Assessment Models in Patients with Severe COVID-19

Introduction  Severe novel corona virus disease 2019 (COVID-19) causes dysregulation of the coagulation system with arterial and venous thromboembolism (VTE). We hypothesize that validated VTE risk scores would have prognostic ability in this population. Methods  Retrospective observational cohort with severe COVID-19 performed in NorthShore University Health System. Patients were >18 years of age and met criteria for inpatient or intensive care unit (ICU) care. The International Medical Prevention Registry on Venous Thromboembolism (IMPROVE) and Caprini scores were calculated and patients were stratified. Results  This study includes 184 patients, mostly men (63.6%), Caucasian (54.3%), 63 years old (interquartile range [IQR]: 24-101), and 57.1% of them required ICU care. Twenty-seven (14.7%) thrombotic events occurred: 12 (6.5%) cases of disseminated intravascular coagulation (DIC), 9 (4.9%) of pulmonary embolism, 5 (2.7%) of deep vein thrombosis, and 1 (0.5%) stroke. Among them, 86 patients (46.7%) died, 95 (51.6%) were discharged, and 3 (1.6%) were still hospitalized. "Moderate risk for VTE" and "High risk for VTE" by IMPROVE score had significant mortality association: (hazard ratio [HR]: 5.68; 95% confidence interval [CI]: 2.93-11.03; p  < 0.001) and (HR = 6.22; 95% CI: 3.04-12.71; p  < 0.001), respectively, with 87% sensitivity and 63% specificity (area under the curve [AUC] = 0.752, p  < 0.001). "High Risk for VTE" by Caprini score had significant mortality association (HR = 17.6; 95% CI: 5.56-55.96; p  < 0.001) with 96% sensitivity and 55% specificity (AUC = 0.843, p  < 0.001). Both scores were associated with thrombotic events when classified as "High risk for VTE" by IMPROVE (HR = 6.50; 95% CI: 2.72-15.53; p  < 0.001) and Caprini scores (HR = 11.507; 95% CI: 2.697-49.104; p  = 0.001). Conclusion  The IMPROVE and Caprini risk scores were independent predictors of mortality and thrombotic events in severe COVID-19. With larger validation, this can be useful prognostic information.

Risks and contraindications of medical compression treatment - A critical reappraisal. An international consensus statement

Objectives

Medical compression therapy is used for non-invasive treatment of venous and lymphatic diseases. Medical compression therapy-associated adverse events and contraindications have been reported, although some contraindications are theoretically based. This consensus statement provides recommendations on medical compression therapy risks and contraindications.

Methods

A systematic literature search of medical compression therapy publications reporting adverse events up until November 2017 was performed. A consensus panel comprising 15 international experts critically reviewed the publications and formulated the recommendations.

Results

Sixty-two publications reporting medical compression therapy adverse events were identified. The consensus panel issued 21 recommendations on medical compression therapy contraindications and adverse event risk mitigation, in addition to reviewing medical compression therapy use in borderline indications. The most frequently reported non-severe medical compression therapy-associated adverse events included skin irritation, discomfort and pain. Very rare but severe adverse events, including soft tissue and nerve injury, were also identified.

Conclusion

This consensus statement summarises published medical compression therapy-associated adverse events and contraindications, and provides guidance on medical compression therapy. Severe medical compression therapy-associated adverse events are very rarely encountered if compression is used correctly and contraindications are considered.

D-dimer levels and risk of recurrence following provoked venous thromboembolism: findings from the RIETE registry

BACKGROUND

Patients with venous thromboembolism (VTE) secondary to transient risk factors may develop VTE recurrences after discontinuing anticoagulation. Identifying at-risk patients could help to guide the duration of therapy.

METHODS

We used the RIETE database to assess the prognostic value of d-dimer testing after discontinuing anticoagulation to identify patients at increased risk for recurrences. Transient risk factors were classified as major (postoperative) or minor (pregnancy, oestrogen use, immobilization or recent travel).

RESULTS

In December 2018, 1655 VTE patients with transient risk factors (major 460, minor 1195) underwent d-dimer measurements after discontinuing anticoagulation. Amongst patients with major risk factors, the recurrence rate was 5.74 (95% CI: 3.19-9.57) events per 100 patient-years in those with raised d-dimer levels and 2.68 (95% CI: 1.45-4.56) in those with normal levels. Amongst patients with minor risk factors, the rates were 7.79 (95% CI: 5.71-10.4) and 3.34 (95% CI: 2.39-4.53), respectively. Patients with major risk factors and raised d-dimer levels (n = 171) had a nonsignificantly higher rate of recurrences (hazard ratio [HR]: 2.14; 95% CI: 0.96-4.79) than those with normal levels. Patients with minor risk factors and raised d-dimer levels (n = 382) had a higher rate of recurrences (HR: 2.34; 95% CI: 1.51-3.63) than those with normal levels. On multivariate analysis, raised d-dimers (HR: 1.74; 95% CI: 1.09-2.77) were associated with an increased risk for recurrences in patients with minor risk factors, not in those with major risk factors.

CONCLUSIONS

Patients with raised d-dimer levels after discontinuing anticoagulant therapy for VTE provoked by a minor transient risk factor were at an increased risk for recurrences.

Risk assessment as a guide for the prevention of cancer-associated thromboembolism

Venous thromboembolism (VTE) is a major source of morbidity and mortality among patients diagnosed with cancer. In addition to an increased risk of VTE, patients with cancer are at higher risk of bleeding while receiving therapeutic anticoagulation. Aggressive and targeted thromboprophylaxis is a crucial practice to avoid the dreaded complications of VTE. Risk assessment models (RAM) are tools developed to identify high-risk patients in whom thromboprophylaxis is beneficial. This review describes the most validated VTE RAMs in patients with cancer.

Correlates of thrombin generation in patients with advanced prostate cancer

Thrombin generation is increased in men with advanced prostate cancer. Thrombin has the ability to interact with, and affect the biology of, a variety of cell types including prostate cancer cell lines. We therefore looked for correlations between thrombin generation and other markers of disease activity in spot urine samples obtained from men with advanced prostate cancer. Excretion of part of the prothrombin activation peptide F1+2 (called here iF2), interleukin-6 (IL-6), the bone turnover marker deoxypyridinoline (DpD), and vascular endothelial growth factor (VEGF) were quantitated in spot urine samples collected from 37 men with hormone-refractory prostate cancer. Following log transformation of the data, significant correlations were found by univariate analysis between the excretion of a marker of thrombin generation (iF2) and IL-6, DpD and VEGF, as well as between IL-6 and DpD or VEGF excretion. No correlation was found between any marker and serum PSA level. After multivariate analysis, a significant correlation remained between thrombin generation and IL-6 excretion. Analysis of a second urine specimen obtained from 19 of the subjects 1 to 7 months after the first also revealed a significant correlation between thrombin generation and IL-6, DpD, and VEGF excretion. These data provide evidence of a correlation between thrombin generation/coagulation system activation and IL-6 generation in patients with cancer. They provide a rationale for studying the effects of inhibitors of thrombin generation upon the biology of prostate cancer.

Efficacy and safety of dabigatran etexilate for the prevention of venous thromboembolism following total hip or knee arthroplasty

Dabigatran etexilate has been investigated in three phase III trials for the prevention of venous thromboembolism (VTE). Health technology assessment agencies increasingly require meta-analyses of all relevant evidence for an intervention, if appropriate. The objective of this study was to perform a meta-analysis of efficacy and safety data for the recommended dose of dabigatran etexilate, 220 mg once daily (od), for VTE prophylaxis after total knee arthroplasty (TKA) and total hip arthroplasty (THA), and discuss the appropriateness of combining the data. Risk ratios (RR) for VTE and bleed end-points were estimated using fixed and random effects meta-analysis. Analyses were performed combining RE-MODEL and RE-NOVATE, which compared dabigatran etexilate with enoxaparin 40 mg od after TKA and THA, respectively, and also including RE-MOBILIZE, which compared dabigatran etexilate with enoxaparin 30 mg twice daily after TKA. Tests for statistical heterogeneity were performed using the Chi-squared statistic. No significant differences were detected between dabigatran etexilate and enoxaparin in any of the end-points analysed, either in the two trial analysis (all p>0.15), or when all three trials were combined ( all p>0.30). RRs (random effects) for the composite end-point total VTE and all-cause mortality were 0.95 [95% confidence intervals 0.82 – 1.10] and 1.05 [0.87 – 1.26] in the two and three trial analyses, respectively. Meta-analysis of RE-MODEL and RE-NOVATE supported the conclusions of the individual trials that dabigatran etexilate is non-inferior to enoxaparin 40 mg od, with a similar safety profile. Meta-analysis of all three trials found no significant differences between treatments in any of the end-points analysed. Heterogeneity between the trials cannot be ruled out.

Validation of a Patient-Completed Caprini Risk Score for Venous Thromboembolism Risk Assessment

Introduction  Individualized risk assessment for venous thromboembolism (VTE) using the Caprini risk score (CRS), coupled with targeted prophylaxis based on the score, is effective in reducing postoperative VTE. Critics contend that using this tool is time consuming for health care providers. We decided to create a patient-completed CRS and conducted a prospective study to compare the scores calculated by a patient with those calculated by a blinded physician for the same patient.

Methods  In phase 1, we interviewed patients in our deep vein thrombosis (DVT) support group who had a history of thrombosis and included their family members to determine areas of misunderstanding in the original CRS. We created a patient-completed form based on these interviews. In phase 2, we further optimized the questions after a CRS-trained, blinded physician scored 20 hospitalized patients during the pilot study. In the final (third) phase, we measured the agreement level between the new form filled out by the trained physicians and those filled out by the patients. The study was approved by our local institutional review board. Using PASS version 11, we determined that a sample size of 37 individuals achieves a power of 80%, to detect a 0.1 difference between the null hypothesis correlation of 0.5 and the alternative hypothesis correlation of 0.7 using a two-sided hypothesis test with a significance level of 0.05. We tabulated the individuals' answers and categorized the scores by using SPSS version 23 to estimate the kappa value, linear correlation, and the Bland–Altman test. A kappa value greater than 0.8 indicated an “almost perfect agreement.”

Results  We tested the first patient-completed CRS version (phase 2) in a 20-patient pilot study. A poor agreement was observed with the body mass index (BMI) responses in multiple iterations, and so we excluded the BMI calculation from the final patient-completed CRS form. We recruited 42 patients with an average age of 55, mostly female (45%), who completed less than college education (62%) to fill out the updated CRS form (phase 3). An almost perfect agreement was found for both the individual questions and the overall score comparing physician and patient answers, resulting in a high correlation ( r  = 0.95). In Bland–Altman, we did not find any trend for extreme values.

Conclusion  We created and validated a patient-completed CRS form that has an excellent agreement level with the physician-completed form. From the results, the physician only needs to calculate the BMI. The average time for a patient to complete the form was 5 minutes. The average time for the physician to finalize the score was approximately 6 minutes. Implementation studies are needed to assess the correlation of the aggregated score, derived from this form, with the occurrence of perioperative VTE.

Abstract 512: Predictors of Mortality in Cancer-Associated Calf Deep Vein Thrombosis

Background: Venous thromboembolism (VTE) is a leading cause of mortality in cancer patients. The outcomes of patients with cancer-associated calf deep vein thrombosis (CDVT), including mortality data, are less understood compared with proximal thrombosis.

Aim: To characterize predictors of mortality among cancer-associated CDVT patients.

Methods: Single institution inception cohort of cancer-associated CDVT patients who presented with thrombosis distal to popliteal level confirmed objectively by ultrasound, computed tomography or VQ scan were independently reviewed. Active cancer was defined as metastatic disease or use of chemotherapy at diagnosis. The Khorana risk score (KRS) suggested for DVT and mortality prediction in cancer was abstracted based on laboratory tests and cancer type at diagnosis. Institutional review board approval was obtained prior to the analysis. Categorical variables are expressed as percentages and continuous variables as median (interquartile range). SPSS software version 22 was used and Chi-square, Mann–Whitney U and Cox proportional hazard were applied.

Results: One hundred nine patients (Men=44 (40%), Age>65=89 (82%), BMI>30=25 (23%), Smoker=59 (54%)) were included. The majority had a low or intermediate KRS (30%-64% respectively). Forty-seven percent died during a median follow-up time of 2.5 years (0.5-3.1). After multivariate analysis, the predictors of mortality were found to be: smoking (Hazard Ratio 2.3; 95%CI 1.2-4.7), metastasis (HR 5.8; 95%CI 2.9-11.7), gastrointestinal cancer (HR 3.9; 95%CI 1.8-8.5), and lung cancer (HR 4.1 95%CI 1.7-10.3). VTE specific variables not associated with mortality included: bilateral CDVT, concomitant pulmonary embolism, multiple vein involvement, filter placement, or a surgery-associated event.

Conclusion: Cancer-specific variables and smoking predicted mortality among CDVT patients in this cohort. Neither the KRS nor VTE specific characteristics were predictive of death. A larger study is necessary to further explore these findings.

Venous hemodynamic changes in lower limb venous disease: the UIP consensus according to scientific evidence

There are excellent guidelines for clinicians to manage venous diseases but few reviews to assess their hemodynamic background. Hemodynamic concepts that evolved in the past have largely remained unchallenged in recent decades, perhaps due to their often complicated nature and in part due to emergence of new diagnostic techniques. Duplex ultrasound scanning and other imaging techniques which evolved in the latter part of the 20th century have dominated investigation. They have greatly improved our understanding of the anatomical patterns of venous reflux and obstruction. However, they do not provide the physiological basis for understanding the hemodynamics of flow, pressure, compliance and resistance. Hemodynamic investigations appear to provide a better correlation with post-treatment clinical outcome and quality of life than ultrasound findings. There is a far better prospect for understanding the complete picture of the patient's disability and response to management by combining ultrasound with hemodynamic studies. Accordingly, at the instigation of Dr Angelo Scuderi, the Union Internationale de Phlebologie (UIP) executive board commissioned a large number of experts to assess all aspects of management for venous disease by evidence-based principles. These included experts from various member societies including the European Venous Forum (EVF), American Venous Forum (AVF), American College of Phlebology (ACP) and Cardiovascular Disease Educational and Research Trust (CDERT). Their aim was to confirm or dispel long-held hemodynamic principles and to provide a comprehensive review of venous hemodynamic concepts underlying the pathophysiology of lower limb venous disorders, their usefulness for investigating patients and the relevant hemodynamic changes associated with various forms of treatment. Chapter 1 is devoted to basic hemodynamic concepts and normal venous physiology. Chapter 2 presents the mechanism and magnitude of hemodynamic changes in acute deep vein thrombosis indicating their pathophysiological and clinical significance. Chapter 3 describes the hemodynamic changes that occur in different classes of chronic venous disease and their relation to the anatomic extent of disease in the macrocirculation and microcirculation. The next four chapters (Chapters 4-7) describe the hemodynamic changes resulting from treatmen by compression using different materials, intermittent compression devices, pharmacological agents and finally surgical or endovenous ablation. Chapter 8 discusses the unique hemodynamic features associated with alternative treatment techniques used by the CHIVA and ASVAL. Chapter 9 describes the hemodynamic effects following treatment to relieve pelvic reflux and obstruction. Finally, Chapter 10 demonstrates that contrary to general belief there is a moderate to good correlation between certain hemodynamic measurements and clinical severity of chronic venous disease. The authors believe that this document will be a timely asset to both clinicians and researchers alike. It is directed towards surgeons and physicians who are anxious to incorporate the conclusions of research into their daily practice. It is also directed to postgraduate trainees, vascular technologists and bioengineers, particularly to help them understand the hemodynamic background to pathophysiology, investigations and treatment of patients with venous disorders. Hopefully it will be a platform for those who would like to embark on new research in the field of venous disease.

Evaluation of the acute coronary syndrome safety profile of dabigatran etexilate in patients undergoing major orthopedic surgery: findings from four Phase 3 trials

INTRODUCTION

Several anticoagulants have been associated with a 'rebound effect' that potentially increases the risk of thrombosis and cardiovascular events following discontinuation. Four Phase 3 trials of dabigatran etexilate in major orthopedic surgery incorporated measures to assess the risk of acute coronary syndrome (ACS) events during and after treatment.

MATERIALS AND METHODS

Patients in RE-MOBILIZE®, RE-MODEL™, RE-NOVATE®, and RENOVATE® II were randomized to dabigatran etexilate (150 mg or 220mg once daily) or enoxaparin for 6-35 days, and followed for up to 90 days. ACS data were tabulated from investigator-reported serious adverse events using ACS-specific Medical Dictionary for Regulatory Authorities (MedDRA) lower-level terms. To ensure that all ACS events were identified in the initial three studies, RE-MOBILIZE®, RE-MODEL™, and RE-NOVATE®, a broader list of MedDRA terms was prespecified that would trigger treatment-blinded adjudication.

RESULTS

When pooling the four trials, patients receiving dabigatran etexilate 220 mg had the fewest treatment-emergent, investigator-reported ACS events (6 [0.16%] vs 14 [0.51%] for dabigatran 150 mg and 13 [0.35%] for enoxaparin). Corresponding post-treatment rates were 2 (0.06%), 1 (0.04%), and 4 (0.11%). Similarly, treatment-emergent centrally adjudicated definite or likely ACS events in the first three trials were fewer in patients on dabigatran 220 mg (16 [0.60%]) than dabigatran 150 mg (26 [0.95%]) and enoxaparin (20 [0.74%]). The corresponding numbers post treatment were 2, 2, and 7. None of these between-group differences were statistically significant.

CONCLUSION

No increased ACS signal was detected with dabigatran etexilate compared with enoxaparin during or after treatment.

Measurement of Lower Leg Compression In Vivo: Recommendations for the Performance of Measurements of Interface Pressure and Stiffness

BACKGROUND

Interface pressure and stiffness characterizing the elastic properties of the material are the parameters determining the dosage of compression treatment and should therefore be measured in future clinical trials.

OBJECTIVE

To provide some recommendations regarding the use of suitable methods for this indication.

METHOD

This article was formulated based on the results of an international consensus meeting between a group of medical experts and representatives from the industry held in January 2005 in Vienna, Austria.

RESULTS

Proposals are made concerning methods for measuring the interface pressure and for assessing the stiffness of a compression device in an individual patient.

CONCLUSIONS

In vivo measurement of interface pressure is encouraged when clinical and experimental outcomes of compression treatment are to be evaluated.

Novel in vitro perfusion model to study the interaction between coagulation and blood-borne metastasis

The association between cancer and hemostasis has long been studied in cell culture, animal models, and cancer patients developing thrombosis. The variety of biologic mechanisms involved in malignancy and metastasis makes the understanding of the relative importance of each mechanism difficult. We have developed a novel in vitro perfusion model that allows for the isolated study of the interactions between tumor cells and components of the hemostatic system under normal physiologic conditions. Segments of denuded umbilical cord or saphenous vein are cut longitudinally and mounted in a perfusion chamber under sterile conditions. Human breast cancer cells are perfused for 24 h under venous flow conditions with either whole blood (WB), platelet-rich plasma (PRP), platelet-poor plasma (PPP), or serum. Tissue samples are fixed and stained with hematoxylin and eosin as well as with pan-cytokeratin. Morphometric analysis is performed to quantify cancer cell adhesion. With PRP, this model maintains normal human physiologic conditions for the duration of the experiment. It differentiates between previously characterized high and low metastatic breast cancer cell lines. In addition, different vein tissue types do not alter tumor cell attachment. This model appears to be an accurate representation of the pathophysiology of in vivo metastasis. This model may serve as a useful bridge between cell culture studies and animal models. It may be a useful tool to elucidate the role of selected hemostatic systems in blood-borne metastasis and may potentially serve as a screening tool for the development of antimetastatic pharmaceutical agents.

Results of an economic model to assess the cost-effectiveness of enoxaparin, a low-molecular-weight heparin, versus warfarin for the prophylaxis of deep vein thrombosis and associated long-term complications in total hip replacement surgery in the United States

BACKGROUND

Premature death due to pulmonary embolism is a short-term complication of deep vein thrombosis (DVT). The long-term clinical course after DVT can be further complicated by excess mortality, recurrent venous thromboembolism (VTE), and the post-thrombotic syndrome (PTS), which may produce sizable long-term economic burdens.

OBJECTIVE

The goal of this study was to determine the cost-effectiveness of the low-molecular-weight heparin (LMWH) enoxaparin versus warfarin for the universal prophylaxis of DVT and associated long-term complications in US patients undergoing total hip replacement surgery (THRS).

METHODS

A model was constructed to assess the long-term cost-effectiveness of the 2 treatments. Patients undergoing THRS were exposed to a short-term risk of developing a DVT. Patients surviving a DVT were exposed to increased risk of long-term complications of DVT, including PTS, recurrent VTE, and increased mortality. Published literature, augmented by expert opinion, served as input for the model's resource use and costs for DVT prophylaxis, clinical diagnosis, and treatment of DVT, VTE, and PTS.

RESULTS

When the analysis included only the short-term consequences of DVT, therapy with enoxaparin resulted in a net cost of $133 per patient and a net increase of 0.04 quality-adjusted life-years (QALYs) per patient. Thromboprophylaxis with enoxaparin versus warfarin resulted in $3733 per QALY saved. In contrast, when the long-term consequences of DVT were included, enoxaparin resulted in net lifetime savings of $89 per patient and net QALY benefits of 0.16 per patient.

CONCLUSIONS

To the best of our knowledge, this is the first US economic analysis comparing DVT prophylaxis with the LMWH enoxaparin versus warfarin that included the long-term complications of DVT. Our model suggests that use of enoxaparin in patients undergoing THRS reduces the economic burden associated with these long-term complications.

Prevention of venous thromboembolism: adherence to the 1995 American College of Chest Physicians consensus guidelines for surgical patients

BACKGROUND

The American College of Chest Physicians addressed the dilemma of identifying optimal therapy for venous thromboembolism (VTE) prophylaxis and published their Fourth Consensus Conference on Antithrombotic Therapy in 1995, with recommendations for prophylactic therapy. Despite these recommendations, appropriate VTE prophylactic therapy is underused.

OBJECTIVES

To examine routine practices in the prevention of VTE in high-risk surgical patients and to determine the extent of adoption of grade A prophylactic therapies as recommended by the American College of Chest Physicians.

METHODS

Retrospective medical record review in 10 teaching or community-based hospitals located in the United States. Medical charts of 1907 patients were randomly selected for review from the population of patients who underwent high-risk major abdominal surgery, total hip replacement, hip fracture repair, or total knee replacement between January 1, 1996, and February 28, 1997.

RESULTS

Of 1907 patients, VTE prophylaxis was used in 89.3%; use was 93.7% in each of the 3 orthopedic surgery groups and 75.2% in the high-risk major abdominal surgery group. The percentage of patients receiving grade A therapy was highest in the hip replacement group (84.3%) vs. the other groups (knee replacement, 75.9%; hip fracture repair, 45.2%; abdominal surgery, 50.3%).

CONCLUSIONS

The use of grade A prophylaxis was related to the type of surgery, with the highest use seen in total hip replacement and the lowest in hip fracture repair. One in 4 patients who underwent high-risk major abdominal surgeries failed to receive any form of VTE prophylaxis. Publication of consensus statements alone may be insufficient to ensure the incorporation of important new clinical information into routine practice.

Volvulus of the small bowel: an uncommon complication after laparoscopic cholecystectomy

We report here two patients with volvulus of the small bowel after laparoscopic cholecystectomy (LC). There has been only one case report of a similar condition after LC in the English literature; the patient had malrotation of the midgut. Both patients we are reporting had previous pelvic surgery resulting in intraabdominal adhesions. Volvulus had occurred along an axis between the mesenteric attachment and the adhesion to the parietal peritoneum of the involved loop of small bowel. The creation of pneumoperitoneum could conceivably allow rotation to occur. One patient presented with signs of peritonitis from a gangrenous segment of small bowel. The other presented with continued abdominal pain after surgery. Definitive diagnosis was made only at laparotomy. Previous surgery is considered a relative contraindication to LC, although the incidence of morbidity and conversion to open procedure appear not to be influenced by previous surgery. Surgeons should be aware of volvulus as a complication after LC in patients who had previous abdominal surgery.