Bo Eklof

Risk factors for venous thromboembolism following prolonged air travel. Coach class thrombosis.

Venous thromboembolism (VTE) in legs and lungs is a potentially life-threatening condition. The incidence of VTE associated with air travel is still unknown, but it may have increased. Most travelers who develop symptoms do so within 24 hours after their flight takes off. Predisposing risk factors may be divided into patient-related and cabin-related factors, both of which are described. It is emphasized that better information and better inflight precautions can minimize these risk factors.

Deep venous valve reconstruction

The place of deep venous valve reconstruction in the surgical management of the patient with chronic venous insufficiency has become clearer with collected experience over the past 25 years. The reasons to perform surgery in chronic venous disease and the specific rationale for deep venous repair are contrasted with the management of the same patient by medical means. A new classification of chronic venous disease has been developed and provides the basis for a more objective understanding of specific entities in the entire field of chronic venous symptoms. The requirements for diagnosis before reconstructive surgery are stringent and a diagnostic algorithm is discussed in the selection of candidates for deep venous reconstruction. The multiple surgical techniques for deep venous reconstruction include internal intravenous direct valve repair and extravenous tightening of the vein wall around the valve cusp. The results of valve repair for primary valve incompetence are discussed in terms of long-term clinical results, long-term imaging results and long-term physiologic results as reflected by venous pressure examinations. It is becoming increasingly clear with the passage of time and the sharpening of our diagnostic skills that reflux is the dominant cause of chronic venous insufficiency. The ability of surgical procedures to decrease reflux in a diseased extremity can be used to restore patients to their normal way of life free of pain, swelling and ulceration and, in the ideal case, free of the need for elastic support.

INDICATIONS FOR SURGICAL TREATMENT OF ILIOFEMORAL VEIN THROMBOSIS

The goals of treatment of acute iliofemoral DVT should be prevention of fatal PE, reduction of pain and swelling of the involved leg, trying to stop the development of phlegmasia cerulea dolens and venous gangrene, prevention of disabling PTS by early removal of the blood clot, avoiding proximal venous obstruction, preserving normal, functioning valves in the leg veins, and preventing reflux. The authors recommend an aggressive approach with rapid removal of the occluding thrombus in the leg veins extending up into the iliac veins in active patients with a short history of symptomatic DVT, usually less than 7 days. This approach is not justified in chronically ill, bedridden, high-risk, or aged patients, or those with serious intercurrent disease or limited life expectancy. In these patients, such interventions can only be indicated for limb salvage in phlegmasia cerulea dolens when conservative treatment does not prevent the development of an acute compartment syndrome with venous gangrene. The preferred means of accomplishing early and quick removal of the thrombus is CDITT. Most of the authors positive experience with thrombolysis is based on the use of urokinase. The Food and Drug Administration (FDA) has put this drug on temporary hold for almost 1 year. The alternative drugs (e.g., tissue plasminogen activator [tPA]) have not been tested for CDITT of DVT, and tPA is not FDA-approved for this indication. When there are contraindications or failure of thrombolysis, TE with a temporary AVF is a valid alternative.

Stent-Graft Arteriovenous Fistula: An Endovascular Technique in Hemodialysis Access

PURPOSEnTo determine the feasibility and safety of a new endovascular technique for creating an arteriovenous (AV) fistula utilizing catheter-directed techniques and stents.nnnMETHODSnStent-graft AV fistulas were offered on an experimental basis to 8 patients who had a history of multiple failed access procedures or very small arm veins unsuitable for standard vascular access techniques. The device consisted of a balloon-expandable Palmaz stent attached to the designated venous end of a polytetrafluoroethylene graft. The balloon-mounted stent-graft was inserted into the brachial vein through an arteriotomy and advanced over a guidewire into the axillary vein. After the stent-graft was deployed, the arterial anastomosis was completed in standard surgical fashion using an end-to-side anastomosis of the graft to the brachial artery.nnnRESULTSnThe stent-graft was inserted successfully in all patients, but there were two early failures. The first resulted from a steal phenomenon secondary to high flows through the stent-graft, necessitating ligation of the fistula. Another stent-graft was placed too peripherally in the upper arm, and the stainless steel stent was crushed by external compression. Three of the 6 remaining grafts were patent for over 1 year, and 2 grafts are still functioning at 22 and 13 months.nnnCONCLUSIONSnEndoluminal stent-grafts can be successfully inserted into the axillary vein for creation of an AV fistula and remain patent for 2 years or more. This method may be most useful in patients with very small, unusable arm veins or multiple failed AV grafts.

Clinical Presentation and Classification of Chronic Venous Disease

Effective communication about diseases of the blood vessels requires a classification that categorizes patients into well-defined groups which can be reliably reproduced. The classification needs to be capable of distinguishing two dissimilar conditions which have the same external appearance by elements in the classification other than the appearance. This is particularly important in chronic venous disease where similar external features, such as discoloration, skin changes, and even ulceration are found in individuals with widely divergent venous pathology. Consider the extremities pictured in Fig. 5.1 and Fig. 5.2. The limb in Fig. 5.1 bears the appearance of the classical “post-phlebitic” leg so often discussed in the literature.

Practical Application of the CEAP Classification

When Rene Leriche described the “obliteration of the terminal abdominal aorta” in 1923, his approach included an organized discussion of the clinical state, etiology, location of the problem and the involved pathophysiology.1 Such an organized approach to arterial disease has become well established in the modern era of vascular surgery since the 1940s. It is surprising that a similar organized approach to the venous system has lagged so far behind its arterial counterpart. Like the treatment of arterial disease, progress in the management of venous disease requires clear identification of four basic elements that describe the venous limb. Ultimately, by knowing the clinical symptom or sign, the etiology of the venous problem, the site involved and the physiologic abnormality, one can formulate a logical treatment plan for the patient.

Venous Reconstruction: Evidence-based Analysis of Results

The purpose of this chapter is to analyze evidence in the literature for the validity of reconstruction in the deep venous system. This must begin with the recognition that there are no large or small randomized studies of different treatments in this field that would satisfy the criteria for Level I or Level II clinical evidence for therapy as defined by Sackett.1 In all of the venous reconstruction literature there is only one trial that is nonrandomized with concurrent controls2 (Level III evidence) while all of the rest of the reports are case series with no controls (Level V evidence). For these reasons, evidence in this subject can only be examined in light of the reliability of the original diagnosis, the types of testing used in the pre-and post-treatment analyses, the size of the various published series and the comparative results of different authors using similar treatment in similar patients.