Safety and Efficacy of Percutaneous Translumbar Inferior Vena Cava Catheters: A Systematic Review and Meta-Analysis

PURPOSE

To examine the reported adverse events associated with inferior vena cava (IVC) catheterization and investigate the reasons for discrepancies between reports.

MATERIALS AND METHODS

Cochrane Library trials register, PubMed, Embase, and Scopus databases were systematically searched for studies that included any terms of IVC and phrases related to catheters or central access. Of the 5,075 searched studies, 137 were included in the full-text evaluation. Of these, 37 studies were included in the systematic review, and the adverse events reported in 16 of these 37 identified studies were analyzed. An inverse-variance random-effects model was used to conduct the meta-analysis. Outcomes were summarized by the incidence rate (IR) and 95% CI.

RESULTS

Compared with that of catheters <10 F in size (IR, 0.08; 95% CI, 0.03-0.12), the incidence of catheter-related infections per 100 catheter days was 0.2 more for catheters ≥10 F in size (IR, 0.28; 95% CI, 0.25-0.31). In addition, dual-lumen catheters showed 0.13 more malfunction per 100 catheter days (IR, 0.27; 95% CI, 0.16-0.37) than that shown by single-lumen catheters (IR, 0.14; 95% CI, 0.09-0.19). Both differences were statistically significant. Other adverse events were malposition (IR, 0.04; 95% CI, 0.04-0.05), fracture (IR, 0.01; 95% CI, 0.00-0.02), kinking (IR, 0.01; 95% CI, 0.00-0.01), replaced catheter (IR, 0.2; 95% CI, 0.1-0.31), removal (IR, 0.13; 95% CI, 0.1-0.16), IVC thrombosis (IR, 0.01; 95% CI, 0.00-0.03), and retroperitoneal hematoma (IR, 0.01; 95% CI, 0.00-0.01), all per 100 catheter days.

CONCLUSIONS

Translumbar IVC access is an option for patients with exhausted central veins. Small-caliber catheters cause fewer catheter-related infections, and single-lumen catheters function longer.

A systematic review of routine post operative screening duplex ultrasound after thermal and non-thermal endovenous ablation

OBJECTIVE

The Society of Vascular Surgery and the American Venous Forum recommend duplex ultrasound (DUS) following endovenous ablation. However, this screening may not be cost-effective or clinically indicated. The most common abnormal finding, endovenous heat-induced thrombosis (EHIT level 1-2), represents extension of thrombus from the saphenous <50% across the femoral or popliteal vein, which is thought to have a benign course regardless of intervention. The likelihood of venous thromboembolism (VTE) after thermal and non-thermal ablations was explored to determine the utility of routine postoperative DUS.

METHODS

This is an updated and expanded systematic review including data from randomized trials and large observational studies (≥150 patients) of thermal and non-thermal ablations, examining the incidence of VTE. Using PubMed and EMBASE, 4584 publications were screened from 2000 through 2020. After applying inclusion and exclusion criteria, 72 studies were included. Random effects DerSimonian-Laird method was conducted to obtain the pooled incidence. We calculated the number of tests needed to detect one VTE, and the cost was derived from Center for Medicare Services tables.

RESULTS

A total of 31,663 patients were included. The pooled incidence of EHIT II-IV, deep venous thrombosis (DVT), and pulmonary embolism (PE) was 1.32% (95% confidence interval [CI], 0.75%-2.02%); DVT (excluding EHIT), 0.20% (95% CI, 0.0%-0.2%); EHIT (I-IV), 2.51% (95% CI, 1.54%-3.68%); and EHIT (II-IV), 1.00% (95% CI, 0.51%-1.61%). There was no mortality. There was a lower DVT rate in thermal vs non-thermal ablations (0.23% vs 0.43%; P = .02); however, for all VTE (EHIT I-IV + DVT + PE), thermal techniques had more thrombosis (2.5% vs 0.5%; P <.001). When clinical significance is defined as DVT + EHIT (II-IV), 175 studies are needed to identify one VTE, costing $21,813 per "significant VTE." Patients receiving pharmacological prophylaxis had less EHIT I-IV compared with those who did not (3.04% vs 1.63%; P < .001); those who received DUS during the first post-op week had three times higher EHIT incidence compared with those whose first DUS was >7 days postoperative (6.6% vs 2.4%; P < .001).

CONCLUSIONS

For thermal and non-thermal endovenous ablations, the incidence of VTE diagnosed with routine DUS is small and without clear clinical significance but caries a high cost. The Society of Vascular Surgery and the American Venous Forum recommendation to perform DUS within 72 hours is not justified by these data. We recommend a more targeted post-ablation scanning protocol including symptomatic patients and those at high risk.

The American Venous Forum, American Vein and Lymphatic Society and the Society for Vascular Medicine expert opinion consensus on lymphedema diagnosis and treatment

BACKGROUND

Lymphedema imposes a significant economic and social burden in modern societies. Controversies about its risk factors, diagnosis, and treatment permeate the literature. The goal of this study was to assess experts' opinions on the available literature on lymphedema while following the Delphi methodology.

METHODS

In December of 2019, the American Venous Forum created a working group tasked to develop a consensus statement regarding current practices for the diagnosis and treatment of lymphedema. A panel of experts was identified by the working group. The working group then compiled a list of clinical questions, risk factors, diagnosis and evaluation, and treatment of lymphedema. Fifteen questions that met the criteria for consensus were included in the list. Using a modified Delphi methodology, six questions that received between 60% and 80% of the votes were included in the list for the second round of analysis. Consensus was reached whenever >70% agreement was achieved.

RESULTS

The panel of experts reached consensus that cancer, infection, chronic venous disease, and surgery are risk factors for secondary lymphedema. Consensus was also reached that clinical examination is adequate for diagnosing lymphedema and that all patients with chronic venous insufficiency (C3-C6) should be treated as lymphedema patients. No consensus was reached regarding routine clinical practice use of radionuclide lymphoscintigraphy as a mandatory diagnostic tool. However, the panel came to consensus regarding the importance of quantifying edema in all patients (93.6% in favor). In terms of treatment, consensus was reached favoring the regular use of compression garments to reduce lymphedema progression (89.4% in favor, 10.6% against; mean score of 79), but the use of Velcro devices as the first line of compression therapy did not reach consensus (59.6% in favor vs 40.4% against; total score of 15). There was agreement that sequential pneumatic compression should be considered as adjuvant therapy in the maintenance phase of treatment (91.5% in favor vs. 8.5% against; mean score of 85), but less so in its initial phases (61.7% in favor vs. 38.3% against; mean score of 27). Most of the panel agreed that manual lymphatic drainage should be a mandatory treatment modality (70.2% in favor), but the panel was split in half regarding the proposal that reductive surgery should be considered for patients with failed conservative treatment.

CONCLUSION

This consensus process demonstrated that lymphedema experts agree on the majority of the statements related to risk factors for lymphedema, and the diagnostic workup for lymphedema patients. Less agreement was demonstrated on statements related to treatment of lymphedema. This consensus suggests that variability in lymphedema care is high even among the experts. Developers of future practice guidelines for lymphedema should consider this information, especially in cases of low-level evidence that supports practice patterns with which the majority of experts disagree.

An Analysis of Guideline Consensus for the Prevention, Diagnosis, and Management of Diabetic Foot Ulcers

BACKGROUND

Multiple organizations have issued guidelines to address the prevention, diagnosis, and management of diabetic foot ulcers (DFUs) based on evidence review and expert opinion. We reviewed these guidelines to identify consensus (or lack thereof) on the nature of these recommendations, the strength of the recommendations, and the level of evidence.

METHODS

Ovid, PubMed, Web of Science, Cochrane Library, and Embase were searched in October 2018 using the MESH term diabetic foot, the key word diabetic foot, and the filters guideline or practice guideline. To minimize recommendations based on older literature, guidelines published before 2012 were excluded. Articles without recommendations characterized by strength of recommendation and level of evidence related specifically to DFU were also excluded. A manual search for societal recommendations yielded no further documents. Recommendations were ultimately extracted from 12 articles. Strength of evidence and strength of recommendation were noted for each guideline recommendation using the Grading of Recommendations Assessment, Development, and Evaluation system or the Centre for Evidence-Based Medicine system. To address disparate grading systems, we mapped the perceived level of evidence and strength of recommendations onto the American Heart Association guideline classification schema.

RESULTS

Recommendations found in two or more guidelines were collected into a clinical checklist characterized by strength of evidence and strength of recommendation. Areas for future research were identified among recommendations based on minimal evidence, areas of controversy, or areas of clinical care without recommendations.

CONCLUSIONS

Through this work we developed a multidisciplinary set of DFU guidelines stratified by strength of recommendation and quality of evidence, created a clinical checklist for busy practitioners, and identified areas for future focused research. This work should be of value to clinicians, guideline-issuing bodies, and researchers. We also formulated a method for the review and integration of guidelines issued by multiple professional bodies.

Private payers' varicose vein policies are inaccurate, disparate, and not evidence based, which mandates a proposal for a reasonable and responsible policy for the treatment of venous disease

Varicose veins afflict more than one in five Americans, and although varicose veins may be an asymptomatic cosmetic concern in some, many others experience symptoms of pain, aching, heaviness, itching, and swelling. More advanced venous disease can result from untreated venous insufficiency. The complications of chronic venous disease, including bleeding, thrombosis, and ulceration, are seen in up to 2 million Americans annually. Numerous reports have documented venous disease adversely affects quality of life and that treatment of venous disease can improve quality of life. It has previously been documented that private insurers, and Centers for Medicare & Medicaid Services subcontractors for that matter, have disparate policies that in many instances are self-serving, contain mistakes, use outdated evidence, and disregard evidence-based guidelines. The two leading venous medical societies, the American Venous Forum and the American Venous and Lymphatic Society, have come together to review the varicose vein coverage policies of seven major U.S. private medical insurance carriers whose policies cover more than 150 million Americans. The authors reviewed the policies for venous disease and, if significant gaps or inconsistencies are found, we hope to point them out, and, finally, to propose a thoughtful and reasonable policy based on the best available evidence.

A systematic review of the quality of cardiovascular surgery studies that extracted data from the MAUDE database

OBJECTIVE

To investigate opportunities and limitations of using the Manufacturer and User Facility Device Experience (MAUDE) database for cardiovascular surgery research, we analyzed the quality of studies having ever used MAUDE, in the field of cardiovascular surgery.

METHODS

We systematically searched the Cochrane Library, PubMed, EMBASE, and Google Scholar for randomized and nonrandomized studies, from inception to July 2019. Two authors evaluated the quality of the retrieved observational studies, according to the National Institutes of Health quality assessment tool for either case series or cross-sectional studies. These tools quantify the quality of case series and cohorts/cross-sectional studies, respectively, with nine and 14 queries.

RESULTS

Fifty-eight studies were included in the final qualitative review. Of 58 identified studies, 32 were case series, 8 were abstracts of case series, and 13 were reviews or case discussion with an included series from MAUDE. Also, five articles were cross-sectional studies. Of the 32 formal case series, 26 (81%) were found to have poor quality. The most common reasons for a poor quality designation included a lack of consecutive participants, undetermined comparability of participants, and undetermined follow-up adequacy. Only one out of five cross-sectional studies had fair quality; four others were evaluated as poor quality studies.

CONCLUSIONS

Cardiovascular surgery studies using the MAUDE database, whether case series or cross-sectional design, are mostly of poor quality. Their low quality is partly caused by poor study design, but mainly by intrinsic limitations to the MAUDE database: cases recruited are not consecutive; patient characteristics are not detailed enough to allow a meaningful comparison of patient characteristics between different patient entries; outcome measures are unclear; there is a limited follow-up; and time-to-event data are lacking. We conclude that the quality of cardiovascular surgery publications that rely on data from MAUDE could be improved if investigators were to extract all relevant data points from MAUDE entries, then apply standard quality assessment tools in compiling and reporting the data. MAUDE might be improved if it used medical case report standards during the process of reporting and indexing adverse events. To calculate the incidence rate of any adverse event, all event-free cases, as well as all adverse events in patients using a device, are required. Neither of these two variables is available in the MAUDE at the time of writing.

The Dynamic Platelet Transcriptome in Obesity and Weight Loss

OBJECTIVE

Adiposity is associated with oxidative stress, inflammation, and glucose intolerance. Previous data suggest that platelet gene expression is associated with key cardiometabolic phenotypes, including body mass index but stable in healthy individuals over time. However, modulation of gene expression in platelets in response to metabolic shifts (eg, weight reduction) is unknown and may be important to defining mechanism. Approach and Results: Platelet RNA sequencing and aggregation were performed from 21 individuals with massive weight loss (>45 kg) following bariatric surgery. Based on RNA sequencing data, we measured the expression of 67 genes from isolated platelet RNA using high-throughput quantitative reverse transcription quantitative PCR in 1864 FHS (Framingham Heart Study) participants. Many transcripts not previously studied in platelets were differentially expressed with bariatric surgical weight loss, appeared specific to platelets (eg, not differentially expressed in leukocytes), and were enriched for a nonalcoholic fatty liver disease pathway. Platelet aggregation studies did not detect alteration in platelet function after significant weight loss. Linear regression models demonstrated several platelet genes modestly associated with cross-sectional cardiometabolic phenotypes, including body mass index. There were no associations between studied transcripts and incident diabetes or cardiovascular end points.

CONCLUSIONS

In summary, while there is no change in platelet aggregation function after significant weight loss, the human platelet experiences a dramatic transcriptional shift that implicates pathways potentially relevant to improved cardiometabolic risk postweight loss (eg, nonalcoholic fatty liver disease). Further studies are needed to determine the mechanistic importance of these observations.

Distal perfusion cannulae reduce extracorporeal membrane oxygenation-related limb ischemia

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is a means of providing cardiopulmonary support that is being increasingly used in patients with acute heart failure. When ECMO cannulae are placed peripherally, their large diameters pose a risk of limb ischemia. Distal perfusion cannulae (DPC) have been proposed as means to reduce risk, but their use is not recommended by the most recent ECMO guidelines. We sought to establish their utility at our institution.

METHODS

We performed a retrospective review of of all patients treated with peripheral VA-ECMO at our institution from 2013-2018. During the first 2 years, DPC were not routinely placed, whereas in the final 4 years, DPC were recommended as part of the ECMO cannulation routine.

RESULTS

One hundred and one patients were treated with peripheral VA-ECMO, with an overall mortality of 61%. By univariate analysis, obesity (47% vs. 75%, P<0.01) and limb ischemia (57% vs. 83%, P<0.05) were associated with increased mortality. DPC were placed prophylactically in 49% of patients. Prophylactic placement of a DPC at the time of cannulation significantly reduced the incidence of limb ischemia (2% vs. 32%, P<0.05), but did not impact mortality (53% vs. 69%, P=0.0953). In patients who did not have a DPC placed during ECMO cannulation and subsequently developed limb ischemia, late DPC placement for limb salvage did not impact mortality.

CONCLUSIONS

Limb ischemia portends a poor outcome in VA-ECMO patients, and prophylactic DPC placement significantly reduces the risk of limb ischemia. We propose prophylactic DPC placement be considered in patients requiring peripheral VA-ECMO.

Correlation of disease comorbidity with prescribed treatment among insured U.S. lymphedema patients

OBJECTIVE

The objective of this study was to define the current forms of treatment in a contemporary population of lymphedema (LED) patients for LED related to breast cancer, the most prevalently diagnosed LED comorbidity in Western countries, and phlebolymphedema with venous leg ulcer (PLEDU), a sequela of chronic venous disease. The goals of LED therapy are to reduce edema, thereby improving function and related symptoms, and to improve skin integrity to prevent development of infection. Treatment is generally nonsurgical: conservative care, including complex physical therapy, manual lymphatic drainage, and compression bandaging; or pneumatic compression device (PCD) therapy by a simple nonprogrammable device or an advanced programmable device.

METHODS

To determine the frequency of individual types of treatment for LED and their relationship to breast cancer-related lymphedema (BCRL) and PLEDU, we queried claims from a deidentified Health Insurance Portability and Accountability Act-compliant commercial administrative insurance database with >165 million members. A total of 26,902 patients identified with LED who had been enrolled with continuous medical benefits for 12 months before and after the index date for the complete years 2012 through 2016 were separated into four treatment categories: no treatment, conservative care, simple PCD (SPCD), and advanced PCD. LED treatment was related to the BCRL and PLEDU comorbidities.

RESULTS

BCRL patients, who represented 32.1% of all study patients, made up 41% of all patients receiving conservative care and 24% of patients receiving PCD therapy. By contrast, PLEDU patients (9.6% of study patients) were proportionally under-represented in the conservative care group (7.8%) but composed a disproportionately high share of the PCD therapy group (17.7%). PLEDU patients represented 23.5% of all LED patients prescribed SPCD therapy, whereas BCRL patients composed 10.3% of total LED patient SPCD prescriptions (P < .001).

CONCLUSIONS

Our analysis of a large health care administrative database showed clear differences between the way BCRL and PLEDU patients are treated. Compared with BCRL patients, PLEDU patients were less likely to receive conservative care and more likely to be prescribed SPCDs for pneumatic compression therapy. These differences suggest that lymphatic therapy may be undervalued for treatment of chronic venous swelling and prevention and treatment of PLEDU.

A systematic review of guidelines for lymphedema and the need for contemporary intersocietal guidelines for the management of lymphedema

OBJECTIVE

Lymphedema (LED) affects an estimated 35 million patients in the United States and a staggering 140,200 million people worldwide, yet LED is the forgotten vascular disease. Whereas the diagnosis and treatment of arterial and venous diseases have been strengthened by the development of clinical practice guidelines (CPGs), few CPGs are available for LED. Moreover, for CPGs to have their greatest impact, they should be both of high quality and developed using the most rigorous evidence-based methods. We performed a systematic review of the available CPGs for LED, which were assessed for breadth of content and methodologic strength.

METHODS

A literature search was conducted from National Guideline Clearinghouse (www.

GUIDELINES

gov), BMJ Clinical Evidence (http://clinicalevidence.bmj.com), and National Institute for Health and Care Excellence (http://www.nice.org.uk) as well as from MEDLINE and Google, which selected 245 documents. After a horizon scan that identified 13 potential CPGs, 4 satisfied the criteria for LED. These were analyzed for inclusion of key elements of diagnosis and treatment.

RESULTS

A horizon scan (abstract review) of the 245 documents identified 10 potential CPGs. Of the 10 documents, 6 claimed to be CPGs, but 2 were limited in scope (rehabilitation or compression only), 2 were consensus statements, 1 was a position statement, and 1 was a systematic review. This process yielded four CPGs: Lymphedema Framework Best Practice for the Management of Lymphedema; Japanese Lymphedema Study Group-A Practice Guideline for the Management of Lymphedema; Clinical Resource Efficiency Support Team Guidelines for the Diagnosis, Assessment and Management of Lymphedema; and Guidelines of the American Venous Forum. Only one of four CPGs was based on a contemporary systematic review (2016 end date of references), whereas the remainder had older systematic reviews (end dates of 2005, 2007, and 2007). Several areas of contemporary diagnosis, treatment, and monitoring of LED were absent.

CONCLUSIONS

This systematic review of available LED CPGs demonstrates a limited number of guidelines. The four CPGs identified lack contemporary references while demonstrating low overall study quality. Therefore, it is imperative for our vascular societies to develop contemporary high-quality evidence-based CPGs for LED, as they have for other vascular diseases.

Proteins Altered by Surgical Weight Loss Highlight Biomarkers of Insulin Resistance in the Community

Objective- Mechanisms of early and late improvements in cardiovascular risk after bariatric surgery and applicability to larger, at-risk populations remain unclear. We aimed to identify proteins altered after bariatric surgery and their relations to metabolic syndrome and diabetes mellitus. Approach and Results- We identified 19 proteins altered in 32 nonfasting plasma samples from a study of patients undergoing bariatric surgery who were evaluated preoperatively (visit 1) versus both early (visit 2; ≈3 months) and late (visit 3; ≈12 months) postoperative follow-up using predefined protein panels (Olink). Using in silico methods and publicly available gene expression repositories, we found that genes encoding 8 out of 19 proteins had highest expression in liver relative to other assayed tissues, with the top biological and disease processes, including major obesity-related vascular diseases. Of 19 candidate proteins in the surgical cohort, 6 were previously measured in >3000 FHS (Framingham Heart Study) participants (IGFBP [insulin-like growth factor binding protein]-1, IGFBP-2, P-selectin, CD163, LDL (low-density lipoprotein)-receptor, and PAI [plasminogen activator inhibitor]-1). A higher concentration of IGFBP-2 at baseline was associated with a lower risk of incident metabolic syndrome (odds ratio per log-normal unit, 0.45; 95% CI, 0.32-0.64; P=7.7×10^-6) and diabetes mellitus (odds ratio, 0.63; 95% CI, 0.49-0.79; P=0.0001) after multivariable adjustment. Conclusions- Using a directed protein quantification platform (Olink), we identified known and novel proteins altered after surgical weight loss, including IGFBP-2. Future efforts in well-defined obesity intervention settings may further define and validate novel targets for the prevention of vascular disease in obesity.

Risk factors associated with the venous leg ulcer that fails to heal after 1 year of treatment

BACKGROUND

Despite regular treatment of venous leg ulcers (VLUs), some fail to heal. Although several risk factors have previously been identified to be associated with the failure of VLUs to heal, the majority of studies are limited to <24-week follow-up.

METHODS

A retrospective cohort study was performed at an academic vascular and wound center. A total of 65 patients with VLUs who were observed for a year or more were identified. These patients underwent a variety of treatments following the Society for Vascular Surgery and American Venous Forum VLU guidelines. Risk factors, which were based on previously defined elements for failure of VLUs to heal after a period of treatment, were examined. Both univariate (unadjusted) and multivariate (adjusted) logistic regression analyses were used to assess the magnitude of effect that a given risk factor had on healing.

RESULTS

Of 65 patients treated for a minimum of 52 weeks, 19 (29%) remained unhealed. By univariate analysis, deep venous disease (P = .01; odds ratio [OR], 5.82; 95% confidence interval [CI], 1.49-22.72), history of deep venous thrombosis (P < .001; OR, 14.06; 95% CI, 3.77-52.39), and depression (P = .04; OR, 3.89; 95% CI, 1.10-13.80) were all shown to be significant risk factors for nonhealing. The patient's race (ie, being nonwhite; P = .02; OR, 103.45; 95% CI, 1.94-5.53 × 10³), deep venous disease (P = .05; OR, 37.0; 95% CI, 1.05-1.31 × 10³), and history of deep venous thrombosis (P = .01; OR, 122.4; 95% CI, 3.09-4.84 × 10³), however, were all shown to be significant for nonhealing under multivariate analysis. In addition, identification of an incompetent perforator (P = .02; OR, 0.006; 95% CI, 9.27 × 10^-5-0.44) was conversely shown to be a good prognostic factor for healing.

CONCLUSIONS

This study confirmed that risk factors known to be associated with the failure of a VLU to heal-deep venous disease and post-thrombotic etiology-were significant at 52 weeks, whereas depression and race (nonwhite) are novel risk factors. An analysis of markers of access to care showed no difference between white and nonwhite, suggesting other factors as a cause. The predominance of deep venous disease in the unhealed vs healed cohort (84% vs 48%) highlights the need for a viable treatment option for deep venous disease due to reflux. Overall, this study emphasizes the need to consider all risk factors when evaluating a patient for VLU to coordinate an effective treatment plan and to identify gaps in our treatment.

Venography versus intravascular ultrasound for diagnosing and treating iliofemoral vein obstruction

OBJECTIVE

The Venogram vs IVUS for Diagnosing Iliac vein Obstruction (VIDIO) trial was designed to compare the diagnostic efficacy of intravascular ultrasound (IVUS) with multiplanar venography for iliofemoral vein obstruction.

METHODS

During a 14-month period beginning July 2014, 100 patients with chronic Clinical, Etiologic, Anatomic, and Pathophysiologic clinical class C4 to C6 venous disease and suspected iliofemoral vein obstruction were enrolled at 11 U.S. and 3 European sites. The inferior vena cava and common iliac, external iliac, and common femoral veins were imaged. Venograms were measured for vein diameter; IVUS provided diameter and area measurements. Multiplanar venograms included three views: anteroposterior and 30-degree right and left anterior oblique views. A core laboratory evaluated the deidentified images, determining stenosis severity as the ratio between minimum luminal diameter and reference vessel diameter, minimal luminal area, and reference vessel area. A 50% diameter stenosis by venography and a 50% cross-sectional area reduction by IVUS were considered significant. Analyses assessed change in procedures performed on the basis of imaging method and concordance of measurements between each imaging method.

RESULTS

Venography identified stenotic lesions in 51 of 100 subjects, whereas IVUS identified lesions in 81 of 100 subjects. Compared with IVUS, the diameter reduction was on average 11% less for venography (P < .001). The intraclass correlation coefficient was 0.505 for vein diameter stenosis calculated with the two methods. IVUS identified significant lesions not detected with three-view venography in 26.3% of patients. Investigators revised the treatment plan in 57 of 100 cases after IVUS, most often because of failure of venography to detect a significant lesion (41/57 [72%]). IVUS led to an increased number of stents in 13 of 57 subjects (23%) and the avoidance of an endovascular procedure in 3 of 57 subjects (5%). Overall, IVUS imaging changed the treatment plan in 57 patients; 54 patients had stents placed on the basis of IVUS detection of significant iliofemoral vein obstructive lesions not appreciated with venography, whereas 3 patients with significant lesions on venography had no stent placed on the basis of IVUS.

CONCLUSIONS

IVUS is more sensitive for assessing treatable iliofemoral vein stenosis compared with multiplanar venography and frequently leads to revised treatment plans and the potential for improved clinical outcome.

Histology and Biaxial Mechanical Behavior of Abdominal Aortic Aneurysm Tissue Samples

Abdominal aortic aneurysms (AAAs) represent permanent, localized dilations of the abdominal aorta that can be life-threatening if progressing to rupture. Evaluation of risk of rupture depends on understanding the mechanical behavior of patient AAA walls. In this project, a series of patient AAA wall tissue samples have been evaluated through a combined anamnestic, mechanical, and histopathologic approach. Mechanical properties of the samples have been characterized using a novel, strain-controlled, planar biaxial testing protocol emulating the in vivo deformation of the aorta. Histologically, the tissue ultrastructure was highly disrupted. All samples showed pronounced mechanical stiffening with stretch and were notably anisotropic, with greater stiffness in the circumferential than the axial direction. However, there were significant intrapatient variations in wall stiffness and stress. In biaxial tests in which the longitudinal stretch was held constant at 1.1 as the circumferential stretch was extended to 1.1, the maximum average circumferential stress was 330 ± 70 kPa, while the maximum average axial stress was 190 ± 30 kPa. A constitutive model considering the wall as anisotropic with two preferred directions fit the measured data well. No statistically significant differences in tissue mechanical properties were found based on patient gender, age, maximum bulge diameter, height, weight, body mass index, or smoking history. Although a larger patient cohort is merited to confirm these conclusions, the project provides new insight into the relationships between patient natural history, histopathology, and mechanical behavior that may be useful in the development of accurate methods for rupture risk evaluation.

Matrix- and plasma-derived peptides promote tissue-specific injury responses and wound healing in diabetic swine

Background

Non-healing wounds are a major global health concern and account for the majority of non-traumatic limb amputations worldwide. However, compared to standard care practices, few advanced therapeutics effectively resolve these injuries stemming from cardiovascular disease, aging, and diabetes-related vasculopathies. While matrix turnover is disrupted in these injuries, debriding enzymes may promote healing by releasing matrix fragments that induce cell migration, proliferation, and morphogenesis, and plasma products may also stimulate these processes. Thus, we created matrix- and plasma-derived peptides, Comb1 and UN3, which induce cellular injury responses in vitro, and accelerate healing in rodent models of non-healing wounds. However, the effects of these peptides in non-healing wounds in diabetes are not known. Here, we interrogated whether these peptides stimulate healing in a diabetic porcine model highly reminiscent of human healing impairments in type 1 and type 2-diabetes.

Methods

After 3–6 weeks of streptozotocin-induced diabetes, full-thickness wounds were surgically created on the backs of adult female Yorkshire swine under general anesthesia. Comb1 and UN3 peptides or sterile saline (negative control) were administered to wounds daily for 3–7 days. Following sacrifice, wound tissues were harvested, and quantitative histological and immunohistochemical analyses were performed for wound closure, angiogenesis and granulation tissue deposition, along with quantitative molecular analyses of factors critical for angiogenesis, epithelialization, and dermal matrix remodeling.

Results

Comb1 and UN3 significantly increase re-epithelialization and angiogenesis in diabetic porcine wounds, compared to saline-treated controls. Additionally, fluorescein-conjugated Comb1 labels keratinocytes, fibroblasts, and vascular endothelial cells in porcine wounds, and Far western blotting reveals these cell populations express multiple fluorescein-Comb1-interacting proteins in vitro. Further, peptide treatment increases mRNA expression of several pro-angiogenic, epithelializing, and matrix-remodeling factors, importantly including balanced inductions in matrix metalloproteinase-2, -9, and tissue inhibitor of metalloproteinases-1, lending further insight into their mechanisms.

Conclusions

Comb1 and UN3 stimulate wound resolution in diabetic Yorkshire swine through upregulation of multiple reparative growth factors and cytokines, especially matrix metalloproteinases and inhibitors that may aid in reversing the proteolytic imbalance characteristic of chronically inflamed non-healing wounds. Together, these peptides should have great therapeutic potential for all patients in need of healing, regardless of injury etiology.

The small saphenous vein and other 'neglected' veins of the popliteal fossa: a review

The small saphenous vein (SSV) and other veins in the popliteal fossa merit little discussion in the literature or in didactic programmes regarding their role in chronic venous insufficiency (CVI) and, in this sense, they are neglected. The purpose of this review is to present both duplex ultrasound findings and the associated clinical characteristics of patients with SSV reflux, from several large series. Both the anatomic variations and the epidemiology of the SSV, as well as other veins of the popliteal fossa, the gastrocnemius veins, Gocamini vein, popliteal area veins and popliteal vein, will be discussed. Findings from our review of the current available literature will demonstrate the important role that these veins play in association with CVI. The implications for open and endovenous surgery will be underlined.

Recurrence of varicose veins after endovenous ablation of the great saphenous vein in randomized trials

BACKGROUND

Recurrence of varicose veins after surgery (REVAS) for saphenous incompetence has been well described after ligation and stripping (L&S) but not after the now most frequently performed method of saphenous ablation, endovenous ablation (EVA). The purpose of this study was to define the overall incidence of REVAS as well as both the sites of reflux and the causes of REVAS through a systematic review and meta-analysis of randomized controlled trials (RCTs) for EVA. These studies have the advantage of prospectively collected data and a uniform duplex follow-up.

METHODS

We searched databases (January 1, 2000 through July 1, 2014) for published RCTs evaluating EVA treatment of great saphenous vein (GSV) incompetence that employed endovenous laser ablation or radiofrequency ablation. RCTs were eliminated that (1) did not have follow-up of at least 2 years, (2) did not obtain postoperative duplex scans, (3) did not clearly report the incidence of recurrent varicosities after GSV ablation, and (4) treated the small saphenous or anterior accessory saphenous veins.

RESULTS

Of the 68 studies screened, 20 RCTs that employed EVA of the GSV were identified. Eight had a follow-up of at least 2 years, but one was eliminated because of lack of information on both the site and cause of REVAS. The resultant seven RCTs provided eight comparisons (one study compared both types of EVA to a comparator arm): three used radiofrequency ablation, and five employed endovenous laser ablation. Overall recurrent varicose veins developed in 125 limbs after EVA (22%), with no difference in the incidence vs the L&S group (22%) based on the number of limbs available at the time of the development of recurrence for both groups, but this incidence is dependent on the length of follow-up after the initial treatment. The two studies with serial follow-up showed an approximate doubling of REVAS over time for both EVA and L&S. By contrast, the cause of REVAS was different between the two methods. Neovascularization occurred in only two limbs (2%) after EVA vs 18 (18%) in the L&S group. Recanalization was the most common cause of REVAS for EVA (32%; 40 of 125 limbs), followed by the development of anterior accessory saphenous vein incompetence (19%; 23 of 125 limbs). In contrast to other reports, incompetent calf perforating veins were an infrequent cause of REVAS (7%; eight of 125).

CONCLUSIONS

There is no difference in the incidence of REVAS for EVA vs L&S, but the causes of REVAS are different with L&S, which has important implications for treatment.

Twenty-Year Analysis of Trends in the Incidence and In-Hospital Mortality for Lower-Extremity Arterial Thromboembolism

Background—

Epidemiology data for lower-extremity arterial thromboembolism (LET) are limited and may result from either acute limb ischemia or an acute exacerbation of critical limb ischemia. Given marked changes in both diagnosis and therapy over the last 2 decades, we hypothesized that this time period would have witnessed reductions in both the incidence and in-hospital mortality of LET.

Methods and Results—

Data from 1988 through 2007 from the National Hospital Discharge Survey were analyzed. All admissions for patients with LET were extracted, and the respective International Classification of Diseases, Ninth Revision, Clinical Modification codes were internally validated for both LET and acute limb ischemia. Descriptive statistics were used. The validity of the codes was good for identifying LET cases but poor for identifying acute limb ischemia cases because many of these acute presentations were attributable to critical limb ischemia. Over the 20-year span, there were 1.76 million cases of LET. The incidence of LET decreased significantly from 42.4 per 100 000 persons between 1988 and 1997 to 23.3 per 100 000 persons between 1998 and 2007. The in-hospital mortality for LET decreased significantly from 8.28% between 1988 and 1997 to 6.34% between 1998 and 2007, and male patients achieved greater mortality reduction compared with female patients. Treatments for acute limb ischemia showed decreasing use of surgical bypass and amputation and increasing rates of catheter-based thrombolysis.

Conclusions—

Over the 20-year study period, there have been significant reductions in both LET incidence and in-hospital mortality. Unfortunately, LET admissions extracted from an administrative database comprise a diverse group of individuals, including those with acute and chronic forms of limb ischemia and iatrogenic arterial injury, limiting the true assessment of ALI incidence.

Defining the radiation "scatter cloud" in the interventional suite

OBJECTIVE

We hypothesized that fluoroscopic imaging creates radiation fields that are unevenly scattered throughout the endovascular suite. We sought to quantify the radiation dose spectrum at various locations during imaging procedures and to represent this in a clinically useful manner.

METHODS

Digital subtraction imaging (Innova 4100; GE Healthcare, Waukesha, Wisc) of the abdomen and pelvis was performed on a cadaver in anteroposterior, left lateral, and right anterior oblique 45° projections. Radiation exposure was monitored in real time with DoseAware dosimeters (Phillips, Houston, Tex) in eight radial projections at distances of 2, 4, and 6 ft from the center of the imaged field, each at 5-ft heights from the floor. Three to five consecutive data points were collected for each location.

RESULTS

At most positions around the angiographic table, radiation exposure decreased as the distance from the source emitter increased; however, the intensity of the exposure varied dramatically around the axis of imaging. With anteroposterior imaging, the radiation fields have symmetric dumbbell shapes, with maximal exposure perpendicular to the table at the level of the gantry. Peak levels at 4 and 6 ft from the source emitter were 2.4 times and 3.4 times higher, respectively, than predicted based on the inverse square law. Maximal radiation exposure was measured in the typical operator position 2 ft away and perpendicular to the table (4.99 mSv/h). When the gantry was rotated 45° and 90°, the radiation fields shifted, becoming more asymmetric, with increasing radiation doses to 10.9 and 69 mSv/h, respectively, on the side of the emitter. Minimal exposure is experienced along the axis of the table, decreasing with distance from the source (<0.77 mSv/h).

CONCLUSIONS

Quantifiable and reproducible radiation scatter is created during interventional procedures. Radiation doses vary widely around the perimeter of the angiography table and change according to imaging angles. These data are easily visualized using contour plots and scatter three-dimensional mesh plots. Rather than the concentric circles predicted by the inverse square law, these data more closely resemble a "scatter cloud." Knowledge of the actual exposure levels within the endovascular environment may help in mitigating these risks to health care providers.

Primary tibial vein aneurysm: a source of pulmonary emboli

OBJECTIVE

To describe a case of a rare type of venous aneurysm (posterior tibial) with associated pulmonary embolus. We will discuss options and considerations germane to the diagnostic evaluation and possible interventions for this challenging clinical scenario.

METHODS

Case presentation and literature review.

RESULTS

A 36-year-old man presented to an outside hospital with a three-day history of left calf pain, acute shortness of breath and syncope elicited by exercise. Work-up demonstrated a pulmonary embolus and a posterior tibial venous aneurysm with mural thrombus. The patient presented to us 18 months later with persistent calf pain seeking an alternative to recommendations of lifelong anticoagulation. The patient was treated with surgical resection of the venous aneurysm with subsequent discontinuation of his anticoagulation. There were no surgical or thrombotic complications of this treatment course and the patient's discomfort improved.

CONCLUSION

Primary aneurysms of the tibial veins as a cause of pulmonary emboli are rare. A review of the literature suggests that anticoagulation alone does not provide effective amelioration of thromboembolic risk from lower extremity venous aneurysms. We have reported a case of successful surgical treatment of a posterior tibial venous aneurysm and recommend that surgical correction be strongly considered for accessible venous aneurysms.

Validation of Venous Clinical Severity Score (VCSS) with other venous severity assessment tools from the American Venous Forum, National Venous Screening Program

BACKGROUND

Several standard venous assessment tools have been used as independent determinants of venous disease severity, but correlation between these instruments as a global venous screening tool has not been tested. The scope of this study is to assess the validity of Venous Clinical Severity Scoring (VCSS) and its integration with other venous assessment tools as a global venous screening instrument.

METHODS

The American Venous Forum (AVF), National Venous Screening Program (NVSP) data registry from 2007 to 2009 was queried for participants with complete datasets, including CEAP clinical staging, VCSS, modified Chronic Venous Insufficiency Quality of Life (CIVIQ) assessment, and venous ultrasound results. Statistical correlation trends were analyzed using Spearman's rank coefficient as related to VCSS.

RESULTS

Five thousand eight hundred fourteen limbs in 2,907 participants were screened and included CEAP clinical stage C0: 26%; C1: 33%; C2: 24%; C3: 9%; C4: 7%; C5: 0.5%; C6: 0.2% (mean, 1.41 ± 1.22). VCSS mean score distribution (range, 0-3) for the entire cohort included: pain 1.01 ± 0.80, varicose veins 0.61 ± 0.84, edema 0.61 ± 0.81, pigmentation 0.15 ± 0.47, inflammation 0.07 ± 0.33, induration 0.04 ± 0.27, ulcer number 0.004 ± 0.081, ulcer size 0.007 ± 0.112, ulcer duration 0.007 ± 0.134, and compression 0.30 ± 0.81. Overall correlation between CEAP and VCSS was moderately strong (r(s) = 0.49; P < .0001), with highest correlation for attributes reflecting more advanced disease, including varicose vein (r(s) = 0.51; P < .0001), pigmentation (r(s) = 0.39; P < .0001), inflammation (r(s) = 0.28; P < .0001), induration (r(s) = 0.22; P < .0001), and edema (r(s) = 0.21; P < .0001). Based on the modified CIVIQ assessment, overall mean score for each general category included: Quality of Life (QoL)-Pain 6.04 ± 3.12 (range, 3-15), QoL-Functional 9.90 ± 5.32 (range, 5-25), and QoL-Social 5.41 ± 3.09 (range, 3-15). Overall correlation between CIVIQ and VCSS was moderately strong (r(s) = 0.43; P < .0001), with the highest correlation noted for pain (r(s) = 0.55; P < .0001) and edema (r(s) = 0.30; P < .0001). Based on screening venous ultrasound results, 38.1% of limbs had reflux and 1.5% obstruction in the femoral, saphenous, or popliteal vein segments. Correlation between overall venous ultrasound findings (reflux + obstruction) and VCSS was slightly positive (r(s) = 0.23; P < .0001) but was highest for varicose vein (r(s) = 0.32; P < .0001) and showed no correlation to swelling (r(s) = 0.06; P < .0001) and pain (r(s) = 0.003; P = .7947).

CONCLUSIONS

While there is correlation between VCSS, CEAP, modified CIVIQ, and venous ultrasound findings, subgroup analysis indicates that this correlation is driven by different components of VCSS compared with the other venous assessment tools. This observation may reflect that VCSS has more global application in determining overall severity of venous disease, while at the same time highlighting the strengths of the other venous assessment tools.

The role of amputation as an outcome measure in cellular therapy for critical limb ischemia: implications for clinical trial design

BACKGROUND

Autologous bone marrow-derived stem cells have been ascribed an important therapeutic role in No-Option Critical limb Ischemia (NO-CLI). One primary endpoint for evaluating NO-CLI therapy is major amputation (AMP), which is usually combined with mortality for AMP-free survival (AFS). Only a trial which is double blinded can eliminate physician and patient bias as to the timing and reason for AMP. We examined factors influencing AMP in a prospective double-blinded pilot RCT (2:1 therapy to control) of 48 patients treated with site of service obtained bone marrow cells (BMAC) as well as a systematic review of the literature.

METHODS

Cells were injected intramuscularly in the CLI limbs as either BMAC or placebo (peripheral blood). Six month AMP rates were compared between the two arms. Both patient and treating team were blinded of the assignment in follow-up examinations. A search of the literature identified 9 NO-CLI trials, the control arms of which were used to determine 6 month AMP rates and the influence of tissue loss.

RESULTS

Fifteen amputations occurred during the 6 month period, 86.7% of these during the first 4 months. One amputation occurred in a Rutherford 4 patient. The difference in amputation rate between patients with rest pain (5.6%) and those with tissue loss (46.7%), irrespective of treatment group, was significant (p = 0.0029). In patients with tissue loss, treatment with BMAC demonstrated a lower amputation rate than placebo (39.1% vs. 71.4%, p = 0.1337). The Kaplan-Meier time to amputation was longer in the BMAC group than in the placebo group (p = 0.067). Projecting these results to a pivotal trial, a bootstrap simulation model showed significant difference in AFS between BMAC and placebo with a power of 95% for a sample size of 210 patients. Meta-analysis of the literature confirmed a difference in amputation rate between patients with tissue loss and rest pain.

CONCLUSIONS

BMAC shows promise in improving AMP-free survival if the trends in this pilot study are validated in a larger pivotal trial. The difference in amp rate between Rutherford 4 & 5 patients suggests that these patients should be stratified in future RCTs.

The utility of screening for deep venous thrombosis in asymptomatic, non-ambulatory neurosurgical patients

OBJECTIVES

Decisions regarding deep venous thrombosis (DVT) prophylaxis are complicated in neurosurgical patients because of the potential for catastrophic bleeding complications. Screening with venous duplex ultrasound (VDUS) may improve outcomes, but can strain hospital resources. Since there is little data to guide VDUS surveillance, we investigated the utility of a comprehensive VDUS screening program in neurosurgical patients.

METHODS

Medical records of patients admitted to the neurosurgical service at a university-affiliated hospital from October 2007 through January 2010 who underwent weekly VDUS of the lower extremities until ambulatory or discharged were retrospectively reviewed. Demographics, comorbidities, interventions, and use of DVT prophylaxis were recorded. All patients in this study were asymptomatic for clinical evidence of DVT. When DVT was identified, VDUS reported its location and progression.

RESULTS

One hundred seventy-four consecutive patients were screened according to the established protocol. They had 312 VDUS studies, 68 (21.8%) of which were positive in 40 (23%) unique patients; 10 were bilateral and two catheter-related. There were no documented pulmonary emboli in this series. Seventeen patients (37.7%) had isolated calf DVT, four of which were bilateral (totaling 21 thrombi), and 9 (20%) had coexistent thrombi in calf and proximal veins. Of the 21 isolated calf DVTs, 15 had follow-up studies and two progressed to the popliteal or ileofemoral vein on follow-up (13.3%). Mechanical prophylaxis was uniformly utilized, but chemical prophylaxis varied based on surgeons' assessment of bleeding risk. DVT developed in 19.3% (28/145) of patients receiving prophylactic medication (unfractionated heparin or low-molecular weight heparin) and 41.4% (12/29) receiving no chemoprophylaxis (P < .001). The only patient characteristic that correlated with DVT risk was a body mass index <30 (9.1% vs 29.4%, P = .01).

CONCLUSIONS

Despite the uniform application of mechanical DVT prophylaxis and the use of chemoprophylaxis in a majority of patients, we found a 23% incidence of DVT in these hospitalized, nonambulatory, neurosurgical patients. No patients with isolated calf DVT had an embolic complication but 13.3% progressed proximally in short-term follow-up. While chemical prophylaxis significantly reduced DVT risk, no factor was sufficiently predictive to exclude patients from screening. These data substantiate the importance of full leg VDUS screening and maximizing DVT prophylaxis in this high risk population.

M118, a novel low-molecular weight heparin with decreased polydispersity leads to enhanced anticoagulant activity and thrombotic occlusion in ApoE knockout mice

Heparin and low-molecular weight heparin (LMWH) are complex, heterogeneous polysaccharides used in the treatment of arterial and venous thrombosis. M118 is a novel LMWH with low polydispersity and pronounced anti-Xa and anti-thrombin (IIa) activity as compared to current LMWHs. To determine if M118 is effective in preventing thrombosis in the setting of a vascular plaque, apolipoprotein E knockout mice fed a high fat diet were injected with M118, enoxaparin, unfractionated heparin, or saline control and examined for arterial thrombosis using a rose bengal laser induced carotid artery injury model. M118 significantly increased the time to occlusion as compared to control and unfractionated heparin but not compared to enoxaparin although fewer M118 treated animals had any vascular occlusion present at the time of protocol completion. Platelet-neutrophil aggregates were studied by flow cytometry and were found to be decreased with M118 as compared to enoxaparin. This is the first published report examining M118, a novel LMWH designed to have low polydispersity and enhanced anticoagulant activity. In an animal model of vascular plaque, M118 is a potent inhibitor of arterial thrombosis and, despite lower in vivo anti-Xa and anti-IIa activity levels, M118 was superior to UFH in the prevention of arterial thrombosis.

Relation of platelet and leukocyte inflammatory transcripts to body mass index in the Framingham heart study

BACKGROUND

Although many genetic epidemiology and biomarker studies have been conducted to examine associations of genetic variants and circulating proteins with cardiovascular disease and risk factors, there has been little study of gene expression or transcriptomics. Quantitative differences in the abundance of transcripts has been demonstrated in malignancies, but gene expression from a large community-based cohort examining risk of cardiovascular disease has never been reported.

METHODS AND RESULTS

On the basis of preliminary microarray data and previously suggested genes from the literature, we measured expression of 48 genes by high-throughput quantitative reverse-transcriptase polymerase chain reaction in 1846 participants of the Framingham Offspring cohort from RNA derived from isolated platelets and leukocytes. A multivariable stepwise regression model was used to assess clinical correlates of quantitative RNA expression. For specific inflammatory platelet-derived transcripts, including ICAM1, IFNG, IL1R1, IL6, MPO, COX2, TNF, TLR2, and TLR4, there were significant associations with higher body mass index (BMI). Compared with platelets, fewer leukocyte-derived transcripts were associated with BMI or other cardiovascular risk factors. Select transcripts were found to be highly heritable, including GPIBA and COX1. Almost uniformly, heritable transcripts were not those associated with BMI.

CONCLUSIONS

Inflammatory transcripts derived from platelets, particularly those part of the nuclear factor kappa B pathway, are associated with BMI, whereas others are heritable. This is the first study, using a large community-based cohort, to demonstrate clinical correlates of gene expression and is consistent with the hypothesis that specific peripheral-blood transcripts play a role in the pathogenesis of coronary heart disease and its risk factors.

Subfascial Endoscopic Perforator Vein Surgery

Chronic venous insufficiency is a tremendous health care problem in western societies. Venous disease can affect any combination of the superficial, deep, and perforator venous systems of the lower extremities. Generally the superficial venous deficits are addressed through sclerotherapy, enovenous ablation, stab phlebectomy, and or stripping. Patients with advanced clinical sequelae (lipodermatosclerosis or ulceration) of CVI should also be evaluated for the presence of incompetent perforating veins. Open surgical approached to the calf perforating veins (ie. Linton procedure) were complicated by significant wound complications and have largely been replaced by the less invasive Subfascial Endoscopic Perforator Surgery (SEPS). The use of SEPS in patients with ulceration has been shown to be safe and to reduce the time that patients will have ulcers during follow-up. This chapter will review the pathophysiology, diagnosis, and treatment of incompetent perforating veins of the legs with particular attention to surgical issues.

Compensatory mechanisms influence hemostasis in setting of eNOS deficiency

The balance between thrombosis and hemorrhage is carefully regulated. Nitric oxide (NO) is an important mediator of these processes, as it prevents platelet adhesion to the endothelium and inhibits platelet recruitment. Although endothelial NO synthase (eNOS)-deficient mice have decreased vascular reactivity and mild hypertension, enhanced thrombosis in vivo has not been demonstrated. To determine the role of endogenous NO in hemostasis, a model of carotid arterial injury and thrombosis was performed using eNOS-deficient and wild-type mice. Paradoxically, the eNOS-deficient animals had a prolongation of time to occlusion compared with the wild-type mice (P < 0.001). Consistent with this finding, plasma markers suggesting enhanced fibrinolysis [tissue plasminogen activator (t-PA) activity and antigen and D-dimer levels] were significantly elevated in eNOS-deficient animals. Vascular tissue expression of t-PA and platelet activity levels were not altered. In endothelial cells, t-PA is stored in Weibel-Palade bodies, and exocytosis of these storage granules is inhibited by NO. Thus in the absence of NO, release of Weibel-Palade body contents (and t-PA) could be enhanced; this observation is also supported by increased von Willebrand factor levels observed in eNOS-deficient animals. In summary, although eNOS deficiency attenuates vascular reactivity and increases platelet recruitment, it is also associated with enhanced fibrinolysis due to lack of NO-dependent inhibition of Weibel-Palade body release. These processes highlight the complexity of NO-dependent regulation of vascular homeostasis. Such compensatory mechanisms may partially explain the lack of spontaneous thrombosis, minimally elevated baseline blood pressure, and normal life span that are seen in animals deficient in a pivotal regulator of vascular patency.

Correlation of duplex ultrasound scanning–derived valve closure time and clinical classification in patients with small saphenous vein reflux: is lesser saphenous vein truly lesser?

OBJECTIVE

We recently identified small saphenous vein (SSV) reflux as a significant risk factor for ulcer recurrence in patients with severe chronic venous insufficiency (CVI) undergoing perforator vein ligation. In this study we examined the role of SSV reflux in patients across the spectrum of CVI.

METHODS

From March 15, 1997, to December 24, 2002, clinical and duplex ultrasound (US) scanning data from all valve closure time studies performed in our vascular laboratory were prospectively recorded. Valve closure time in the deep and superficial leg veins was assessed with the rapid cuff deflation technique; reflux time greater than 0.5 seconds was considered abnormal. SSV reflux was correlated with the CEAP classification system and eventual surgical procedure. Data were analyzed with Pearson chi(2) analysis.

RESULTS

We analyzed 722 limbs in 422 patients, 265 (63%) female patients and 157 (37%) male patients, with a mean age of 48 +/- 12.8 years (range, 16-85 years). In the entire cohort the cause was congenital (Ec) in 5 patients, primary (Ep) in 606 patients, and secondary (Es) in 112 patients. SSV reflux was present in 206 limbs (28.5%) evaluated. Among limbs with SSV reflux, Ec = 4 (2%), Ep = 162 (79%), and Es = 40 (19%). SSV reflux did not correlate with gender, side, or age. The prevalence of SSV reflux increases with increasing severity of clinical class: C1-C3, 25.8% versus C4-C6, 36.1% (P =.006). SSV reflux is highly associated with deep venous reflux, 35.2% of femoral vein reflux (P =.015), 35.8% of femoral vein plus popliteal vein reflux (P =.001), and 40.5% of isolated popliteal vein reflux (P <.001). Great saphenous vein (GSV) reflux was identified in 483 (67%) limbs studied with valve closure time, whereas SSV reflux was present in 206 (28%) limbs. In this cohort, 127 GSV or SSV surgical procedures were performed subsequent to valve closure time examination. Among these operations 107 (84%) were GSV procedures, and only 20 (16%) were SSV procedures.

CONCLUSION

SSV reflux is most common in patients demonstrating severe sequelae of CVI, such as lipodermatosclerosis or ulceration. The increasing prevalence of SSV reflux in more severe clinical classes and the strong association of SSV reflux and deep venous reflux suggest that SSV may have a significant role in CVI. Our data further show that, in our institution, a GSV with reflux is more than twice as likely to be surgically corrected as an SSV with reflux. It is time for the SSV to assume greater importance in the treatment of lower extremity venous disease. Future improvements in surgical techniques for access and visualization of the SSV may facilitate this method.

Systematic review of outcomes after surgical management of venous disease incorporating subfascial endoscopic perforator surgery

INTRODUCTION

In the United States more than 6 million persons have chronic venous insufficiency and more than 500,000 have venous ulcers. Patients in whom conservative therapies fail may improve after surgical treatment of superficial and perforating venous disease, but the degree of this benefit is uncertain.

PURPOSE

We performed a systematic review of health outcomes in patients with severe chronic venous insufficiency treated with surgical management that incorporated subfascial endoscopic perforator surgery (SEPS), to quantify the overall rates of surgical outcomes.

METHODS

Published studies in English reporting venous ulcer healing and recurrence outcomes after SEPS were obtained from a MEDLINE search. Data regarding patient characteristics and surgical outcomes were abstracted from each study, and the outcomes were combined by using a random effects model.

RESULTS

Our search identified 20 studies, 1 randomized trial and 19 case series, involving 1140 treated limbs. CEAP classification was secondary cause (E(S)) in 36%, deep venous involvement (A(D))in 56%, and obstructive (P(O)) in 12%. Overall, after surgical treatment including SEPS, with or without concomitant superficial venous ablation, ulcers in 88% of limbs healed. Ulcers recurred in 13%, at mean time of 21 months. Risk factors for nonhealing and recurrence included postoperative incompetent perforator veins, pathophysiologic obstruction, secondary cause, and ulcer diameter greater than 2 cm. Complications and their overall rates after surgical treatment including SEPS were wound infection (6%), hematoma (9%), neuralgia (7%), and deep venous thrombosis (1%).

CONCLUSION

Our results suggest that surgical management of venous ulcer including SEPS, with or without saphenous ablation, leads to an 88% chance of ulcer healing and a 13% chance of ulcer recurrence over the short term. Randomized controlled trials are needed to discern the contributions of compression therapy, superficial venous surgery, and SEPS in the treatment of venous ulcer disease.

Microthrombectomy reduces postsclerotherapy pigmentation: multicenter randomized trial

OBJECTIVE

Postsclerotherapy pigmentation occurs in nearly 30% of patients. Hemosiderin, from degradation of the venous thrombus, is the possible cause. The hypothesis that early removal of the thrombus may eliminate or decrease the incidence of pigmentation has not been proved or documented. The objective of this study was to investigate the effects of early microthrombectomy on incidence of postsclerotherapy pigmentation.

MATERIAL AND METHODS

This multicenter, randomized, controlled study involved 101 patients with varicose veins (100 women, 1 man; mean age, 46 years [range, 25-68 years]). Patients were divided into two groups, with veins 1 mm or less in diameter (group 1, n = 50) or veins 3 mm or less in diameter (group 2, n = 51). Group 1 was treated with Sotradecol (STD) 0.25%, and group 2 with STD 0.50%. In each patient, an area of varicosities was selected and divided into halves. One half was randomized to microthrombectomy and the other half served as control. Microthrombectomy was performed 1 to 3 weeks after treatment in the randomized half. Standard photographs were obtained before and 16 weeks after treatment, and were evaluated by three independent reviewers who were blinded to treatment assignments. Each reviewer received an identical set of pretreatment and posttreatment 10 x 15-cm color photographs of the study area, and completed a scoring sheet. Average of the scores was used to evaluate primary (pigmentation) and secondary (overall clinical improvement) end points. The paired t test and chi-square test were used for statistical analysis.

RESULTS

In group 1, microthrombectomized areas had statistically significant less pigmentation (P =.0047) and better overall clinical improvement scores (P =.0002) compared with the control side. In group 2 there was no significant difference between the two areas, but patients reported significant relief of pain and inflammation associated with postsclerotherapy thrombophlebitis.

CONCLUSION

In veins 1 mm or smaller, microthrombectomy reduced pigmentation and improved overall clinical results. In veins 3 mm or smaller, statistical significance was not achieved, but thrombectomy resulted in faster resolution of the postsclerotherapy pain and inflammation. On the basis of these results, microthrombectomy after sclerotherapy is recommended.